Sample records for biological nutrient removal

  1. Biological Nutrient Removal in Compact Biofilm Systems

    NARCIS (Netherlands)

    Bassin, J.P.


    The removal of nutrients such as nitrogen and phosphorus from both domestic and industrial wastewaters is imperative since they potentially harm the environment. One of the main consequences of excessive availability of nitrogen and phosphorus in aquatic ecosystems (freshwater, marine and estuarine)

  2. Benchmarking Biological Nutrient Removal in Wastewater Treatment Plants

    DEFF Research Database (Denmark)

    Flores-Alsina, Xavier; Gernaey, Krist; Jeppsson, Ulf


    This paper examines the effect of different model assumptions when describing biological nutrient removal (BNR) by the activated sludge models (ASM) 1, 2d & 3. The performance of a nitrogen removal (WWTP1) and a combined nitrogen and phosphorus removal (WWTP2) benchmark wastewater treatment plant...

  3. Nutrient release, recovery and removal from waste sludge of a biological nutrient removal system. (United States)

    Wang, Yi; Zheng, Shu-Jian; Pei, Li-Ying; Ke, Li; Peng, Dang-Cong; Xia, Si-Qing


    The uncontrolled release of nutrients from waste sludge results in nitrogen and phosphorus overloading in wastewater treatment plants when supernatant is returned to the inlet. A controlled release, recovery and removal of nutrient from the waste sludge of a Biological Nutrient Removal system (BNR) are investigated. Results showed that the supernatant was of high mineral salt, high electrical conductivity and poor biodegradability, in addition to high nitrogen and phosphorus concentrations after the waste sludge was hydrolysed through sodium dodecyl sulphate addition. Subsequently, over 91.8% of phosphorus and 10.5% of nitrogen in the supernatants were extracted by the crystallization method under the conditions of 9.5 pH and 400 rpm. The precipitate was mainly struvite according to X-ray diffraction and morphological examination. A multistage anoxic-oxic Moving Bed Biofilm Reactor (MBBR) was then adopted to remove the residual carbon, nitrogen and phosphorus in the supernatant. The MBBR exhibited good performance in simultaneously removing carbon, nitrogen and phosphorus under a short aeration time, which accounted for 31.25% of a cycle. Fluorescence in situ hybridization analysis demonstrated that nitrifiers presented mainly in floc, although higher extracellular polymeric substance content, especially DNA, appeared in the biofilm. Thus, a combination of hydrolysis and precipitation, followed by the MBBR, can complete the nutrient release from the waste sludge of a BNR system, recovers nutrients from the hydrolysed liquor and removes nutrients from leftovers effectively.

  4. Prefermentation of liquid dairy manure to support biological nutrient removal. (United States)

    Güngör, Kerem; Müftügil, Mert B; Ogejo, Jactone Arogo; Knowlton, Katharine F; Love, Nancy G


    A continuously operated, intermittently fed reactor (fermenter) system with a 2-d solids retention time was proposed for supporting biological nutrient removal from liquid dairy manure. The first objective of this study was to select a material with high fermentation potential to be used as the fermenter feed. Primary sludge, liquid separated dairy manure, and flushed dairy manure were investigated for their fermentation potential. Liquid separated dairy manure had the highest fermentation potential, 0.73mg volatile fatty acid as chemical oxygen demand/mg of initial volatile suspended solids (VSS). The second objective was to investigate the performance of a pilot-scale fermenter operated under an average organic loading rate (OLR) of 3 kg-VSS/m(3)/d. The reactor utilized 18% of the manure fermentation potential. Performance comparison of the pilot-scale fermenter and a lab-scale fermenter with an average OLR of 7 kg-VSS/m(3)/d highlighted the need to increase the OLR of the pilot-scale fermenter so that it can exploit a higher fraction of the manure fermentation potential. A continuously operated, intermittently fed fermenter with 2-d SRT can utilize the majority of the manure fermentation potential and support a downstream BNR reactor provided that it receives a sufficiently high OLR.

  5. Benchmarking biological nutrient removal in wastewater treatment plants: influence of mathematical model assumptions

    DEFF Research Database (Denmark)

    Flores-Alsina, Xavier; Gernaey, Krist V.; Jeppsson, Ulf


    This paper examines the effect of different model assumptions when describing biological nutrient removal (BNR) by the activated sludge models (ASM) 1, 2d & 3. The performance of a nitrogen removal (WWTP1) and a combined nitrogen and phosphorus removal (WWTP2) benchmark wastewater treatment plant...

  6. Circulating fluidized bed biological reactor for nutrients removal

    Institute of Scientific and Technical Information of China (English)

    Yubo CUI; Hongbo LIU; Chunxue BAI


    A new biological nitrogen removal process, which is named herein "The circulating fluidized bed bio-reactor (CFBBR)", was developed for simultaneous removal of nitrogen and organic matter. This process was composed of an anaerobic bed (Riser), aerobic bed (Downer) and connecting device. Influent and nitrified liquid from the aerobic bed enters the anaerobic bed from the bottom of the anaerobic bed, completing the removal of nitrogen and organic matter. The system performance under the conditions of different inflow loadings and nitrified liquid recirculation rates ranging from 200% to 600% was examined. From a technical and economic point of view, the optimum nitrified liquid recirculation rate was 400%. With a shortest total retention time of 2.5 h (0.8 h in the anaerobic bed and 1.5 h in the aerobic bed) and a nitrified liquid recir-culation rate of 400% based on the intluent flow rate, the average removal efficiencies of total nitrogen (TN) and sol-uble chemical oxygen demand (SCOD) were found to be 88% and 95%, respectively. The average effluent concentra-tions of TN and SCOD were 3.5 mg/L and 16 mg/L, respectively. The volatile suspended solid (VSS) concentra-tion, nitrification rate and denitrification rate in the system were less than 1.0 g/L, 0.026-0.1 g NH4+-N/g VSS.d, and 0.016-0.074 g NOx--N/g VSS.d, respectively.

  7. Effects of Sludge Retention Times on Nutrient Removal and Nitrous Oxide Emission in Biological Nutrient Removal Processes

    Directory of Open Access Journals (Sweden)

    Bo Li


    Full Text Available Sludge retention time (SRT is an important factor affecting not only the performance of the nutrient removal and sludge characteristics, but also the production of secondary pollutants such as nitrous oxide (N2O in biological nutrient removal (BNR processes. Four laboratory-scale sequencing batch reactors (SBRs, namely, SBR5, SBR10, SBR20 and SBR40 with the SRT of 5 d, 10 d, 20 d and 40 d, respectively, were operated to examine effects of SRT on nutrient removal, activated sludge characteristics and N2O emissions. The removal of chemical oxygen demand or total phosphorus was similar under SRTs of 5–40 d, SRT mainly affected the nitrogen removal and the optimal SRT for BNR was 20 d. The molecular weight distribution of the effluent organic matters was in the range of 500–3,000 Da under SRTs of 5–40 d. The lowest concentration of the effluent soluble microbial products concentration was obtained at the SRT of 5 d. Nitrifier growth was limited at a short SRT and nitrite existed in the effluent of SBR5. With increasing SRTs, mixed liquor suspended solids concentration increased while the excess sludge production was reduced due to the high endogenous decay rate at high SRTs. Endogenous decay coefficients were 0.020 d−1, 0.036 d−1, 0.037 d−1 and 0.039 d−1 under SRTs of 5–40 d, respectively. In BNR, the N2O emission occurred mainly during the aerobic phase and its emission ratio decreased with increasing SRTs. The ratio between the N2O-N emission and the removed ammonium nitrogen in the aerobic phase was 5%, 3%, 1.8% and 0.8% at the SRT of 5 d, 10 d, 20 d and 40 d, respectively. With low concentrations of dissolved oxygen and high concentrations of oxidized nitrogen, the N2O emission was significantly accelerated due to heterotrophic denitrification activities.

  8. Assessment of the removal of estrogenicity in biological nutrient removal wastewater treatment processes

    Energy Technology Data Exchange (ETDEWEB)

    Ogunlaja, O.O., E-mail:; Parker, W.J., E-mail:


    The removal of estrogenicity in a University of Cape Town-biological nutrient removal (UCT-BNR) wastewater treatment process was investigated using pilot and bench scale systems, batch experiments and mathematical modeling. In the pilot BNR process, 96 ± 5% of the estrogenicity exerted by the influent wastewater was removed by the treatment process. The degradation efficiencies in the anaerobic, anoxic and aerobic zones of the pilot BNR bioreactor were 11 ± 9%, 18 ± 2% and 93 ± 10%, respectively. In order to further understand the performance of the BNR process in the removal of estrogenicity from wastewater, a bench scale BNR process was operated with synthetic wastewater dosed with E1 and E2. The removal of estrogenicity in the bench scale system (95 ± 5%) was comparable to the pilot BNR process and the degradation efficiencies were estimated to be 8 ± 0.8%, 38 ± 4% and 85 ± 22% in the anaerobic, anoxic and aerobic zones, respectively. A biotransformation model developed to predict the fate of E1 and E2 in batch tests using the sludge from the BNR process was calibrated using the data from the experiments. The biotransformation rate constants for the transformation of E2 to E1 were estimated as 71 ± 1.5, 31 ± 3.3 and 1 ± 0.9 L g COD{sup −1} d{sup −1} for the aerobic, anoxic and anaerobic batch tests, respectively, while the corresponding biotransformation rate constants for the transformation of E1 were estimated to be 7.3 ± 1.0, 3 ± 2.0, and 0.85 ± 0.6 L·g COD{sup −1} d{sup −1}. A steady state mass balance model formulated to describe the interactions between E2 and E1 in BNR activated sludge reasonably described the fate of E1 and E2 in the BNR process. - Highlights: • Comparable estrogenicity removal was observed from two BNR processes. • Pseudo first order model described the transformation of E2 and E1 in BNR process. • Biotransformation of E1 in BNR activated sludge controls the degradation of E2.

  9. Economic Benefits of Advanced Control Strategies in Biological Nutrient Removal Systems

    DEFF Research Database (Denmark)

    Carstensen, J.; Nielsen, M.K.; Harremoës, Poul


    Advances in on-line monitoring of nutrient salt concentrations and computer technology has created a large potential for the implementation of advanced and complex control strategies in biological nutrient removal systems. The majority of wastewater treatment plants today are operated with very...... strategies incorporating information from the grey box models are capable of reducing the total nitrogen discharge as well as energy costs. These results have a major impact on both existing and future plants. In fact, it is expected that future plants can be reduced with 10-20 per cent in size......, and that the complexity in reactor design of biological nutrient removal systems will be substituted by complexity in control in the future....

  10. A Modified Oxidation Ditch with Additional Internal Anoxic Zones for Enhanced Biological Nutrient Removal

    Institute of Scientific and Technical Information of China (English)

    LIU Wei; YANG Dianhai; XU Li; SHEN Changming


    A novel modified pilot scale anaerobic oxidation ditch with additional internal anoxic zones was operated experimentally,aiming to study the improvement of biological nitrogen and phosphorus removal and the effect of enhanced denitrifying phosphorus removal in the process.Under all experimental conditions,the anaerobic-oxidation ditch with additional internal anoxic zones and an internal recycle ratio of 200% had the highest nutrient removal efficiency.The effluent NH+4-N,total nitrogen(TN),PO34--P and total phosphorus(TP)contents were 1.2 mg·L-1,13 mg·L-1,0.3 mg·L-1 and 0.4 mg·L-1,respectively,all met the discharge standards in China.The TN and TP removal efficiencies were remarkably improved from 37% and 50% to 65% and 88% with the presence of additional internal anoxic zones and internal recycle ratio of 200%.The results indicated that additional internal anoxic zones can optimize the utilization of available carbon source from the anaerobic outflow for denitrification.It was also found that phosphorus removal via the denitrification process was stimulated in the additional internal anoxic zones,which was beneficial for biological nitrogen and phosphorus removal when treating wastewater with a limited carbon source.However,an excess internal recycle would cause nitrite to accumulate in the system.This seems to be harmful to biological phosphorus removal.

  11. Diversity and importance of filamentous bacteria in biological nutrient removal wastewater treatment plants – a worldwide survey

    DEFF Research Database (Denmark)

    Nierychlo, Marta; Ziegler, Anja Sloth; McIlroy, Simon Jon;

    bacteria in full-scale nutrient removal WWTPs. 16S rRNA gene amplicon sequencing was applied to survey 24 Danish and 30 worldwide full-scale biological nutrient removal WWTPs (total of >550 samples), where all known bacterial genera possessing filamentous morphology were investigated. Candidatus Microthrix...

  12. Behaviors of intercellular materials and nutrients in biological nutrient removal process supplied with domestic wastewater and food waste. (United States)

    Chae, So-Ryong; Jeong, Hyeong-Seok; Lim, Jae-Lim; Kang, Seok-Tae; Shin, Hang-Sik; Paik, Byeong-Cheon; Youn, Jong-Ho


    A four-stage biological nutrient removal (BNR) process was operated to investigate the effect of anaerobically fermented leachate of food waste (AFLFW) as an external carbon source on nutrient removal from domestic wastewater having a low carbon-to-nitrogen ratio. The BNR system that was supplemented with AFLFW showed a good performance at a sludge retention time (SRT) of 30 days, despite low temperature. With this wastewater, average removal efficiencies of soluble chemical oxygen demand (COD), total nitrogen (T-N), and total phosphorus (T-P) were 88 to 93%, 70 to 74%, and 63 to 68%, respectively. In this study, several kinds of poly-hydroxyalkanoates (PHAs) were observed in cells. These included 24% poly-3-hydroxybutyrate (PHB), 41% poly-3-hydroxyvalerate (PHV), 18% poly-3-hydroxyhexanoate (PHH), 10% poly-3-hydroxyoctanoate (PHO), 5% poly-3-hydroxydecanoate (PHD). and 2% poly-3-hydroxydodecanoate (PHDD), indicating that microorganisms could store various PHAs through the different metabolic pathways. However, breakdown of the enhanced biological phosphorus removal (EBPR) mechanism was observed when SRT increased from 30 to 50 days for the enhancement of nitrification. To study the effect of SRT on EBPR, a sequencing batch reactor (SBR) system that was supplied with glucose was operated at various SRTs of 5, 10, and 15 days. Nitrification and denitrification efficiencies increased as SRT increased. However, the content of intracellular materials such as PHAs, glycogen. and poly-P in cells decreased. From these results, it was concluded that SRT should be carefully controlled to increase nitrification activity and to maintain biological phosphorus removal activity in the BNR process.

  13. Enhanced biological nutrient removal in a simultaneous fermentation, denitrification and phosphate removal reactor using primary sludge as internal carbon source. (United States)

    Zhang, Liang; Zhang, Shujun; Wang, Shuying; Wu, Chengcheng; Chen, Yinguang; Wang, Yayi; Peng, Yongzhen


    The production of volatile fatty acids (VFAs) from primary sludge and the subsequent application to improve biological nutrient removal has drawn much attention. In this study, a novel approach of using primary sludge as an additional carbon source was conducted in batch tests. The nitritation effluent was directly injected into the sludge fermentation reactor to achieve nitrogen removal. Complete denitrification could be realized in the combined reactor. Moreover, injecting nitrite not only promoted the sludge stabilization process, but also reduced the release of phosphate and ammonium during sludge stabilization. The novel process was further evaluated in a continuous system by treating sludge dewatering liquors. Under optimum conditions, 85% removal of ammonium and 75% of total nitrogen could be obtained using primary sludge, resulting in the suitable effluent for recycling into the inlet of the wastewater treatment plant.

  14. Simulation and applications of a novel modified SBR system for biological nutrient removal. (United States)

    Wu, W; Timpany, P; Dawson, B


    Dynamic simulation and applications of a novel, continuous-fed, constant level modified sequencing batch reactor for biological nutrient removal are presented. The underlying mathematical model and practical applications of the simulation are discussed. Case studies are presented to illustrate the applications as well as the flexibility of the system in meeting different wastewater treatment requirements. Operation experience from full-scale wastewater treatment plant demonstrates the reliability, ease of operation and high efficiency of the system. Average BOD5, total nitrogen, total phosphorus and TSS removals of 97, 81, 88 and 94% are achieved respectively on an annual basis with little operator attention. Consistently high waste activated sludge concentrations are demonstrated, averaging approximately 20,000 mg/L.

  15. The role and control of sludge age in biological nutrient removal activated sludge systems. (United States)

    Ekama, G A


    The sludge age is the most fundamental and important parameter in the design, operation and control of biological nutrient removal (BNR) activated sludge (AS) systems. Generally, the better the effluent and waste sludge quality required from the system, the longer the sludge age, the larger the biological reactor and the more wastewater characteristics need to be known. Controlling the reactor concentration does not control sludge age, only the mass of sludge in the system. When nitrification is a requirement, sludge age control becomes a requirement and the secondary settling tanks can no longer serve the dual purpose of clarifier and waste activated sludge thickeners. The easiest and most practical way to control sludge age is with hydraulic control by wasting a defined proportion of the reactor volume daily. In AS plants with reactor concentration control, nitrification fails first. With hydraulic control of sludge age, nitrification will not fail, rather the plant fails by shedding solids over the secondary settling tank effluent weirs.

  16. Biological nutrient removal from leachate using a pilot liquid-solid circulating fluidized bed bioreactor (LSCFB). (United States)

    Eldyasti, Ahmed; Chowdhury, Nabin; Nakhla, George; Zhu, Jesse


    Biological treatment of landfill leachate is a concern due to toxicity, high ammonia, low biodegradable organic matter concentrations, and low carbon-to-nitrogen ratio. To study the reliability and commercial viability of leachate treatment using an integrated liquid-solid circulating fluidized bed bioreactor (LSCFB), a pilot-scale LSCFB was established at the Adelaide Pollution Control Plant, London, Ontario, Canada. Anoxic and aerobic columns were used to optimize carbon and nutrient removal capability from leachate using 600 microm lava rock with a total porosity of 61%, at empty bed contact times (EBCTs) of 0.55, 0.49, and 0.41 d. The LSCFB achieved COD, nitrogen, and phosphorus removal efficiencies of 85%, 80%, and 70%, respectively at a low carbon-to-nitrogen ratio of 3:1 and nutrients loading rates of 2.15 kg COD/(m(3) d), 0.70 kg N/(m(3) d), and 0.014 kg P/(m(3) d), as compared with 60-77% COD and 70-79% nitrogen removal efficiencies achieved by upflow anaerobic sludge blanket (UASB) and moving bed bioreactor (MBBR), respectively. The LSCFB effluent characterized by biological solids retention times (SRTs) of 31, 38 and 44 d.

  17. Impact of membrane solid-liquid separation on design of biological nutrient removal activated sludge systems. (United States)

    Ramphao, M; Wentzel, M C; Merritt, R; Ekama, G A; Young, T; Buckley, C A


    Installing membranes for solid-liquid separation into biological nutrient removal (BNR) activated sludge (AS) systems makes a profound difference not only in the design of the BNR system itself, but also in the design approach for the whole wastewater treatment plant (WWTP). In multizone BNR systems with membranes in the aerobic reactor and fixed volumes for the anaerobic, anoxic, and aerobic zones (i.e., fixed volume fractions), the mass fractions can be controlled (within a range) with the interreactor recycle ratios. This zone mass fraction flexibility is a significant advantage in membrane BNR systems over conventional BNR systems with SSTs, because it allows for changing of the mass fractions to optimize biological N and P removal in conformity with influent wastewater characteristics and the effluent N and P concentrations required. For PWWF/ADWF ratios in the upper range (f(q) approximately 2.0), aerobic mass fractions in the lower range (f(maer) secondary settling tanks is not as large (40% to 60%), the cost of the membranes can be offset against sludge thickening and stabilization costs. Moving from a flow-unbalanced raw wastewater system to a flow-balanced (f(q) = 1), low (usually settled) wastewater strength system can double the ADWF capacity of the biological reactor, but the design approach of the WWTP changes from extended aeration to include primary sludge stabilization. The cost of primary sludge treatment then has to be paid from the savings from the increased WWTP capacity.

  18. Troubleshooting a Full-scale Wastewater Treatment Plant for Biological Nutrient Removal

    Directory of Open Access Journals (Sweden)

    Oleyiblo Oloche James


    Full Text Available The International Association of Water Quality (IAWQ Activated Sludge Model No.2 (ASM2 was applied to troubleshoot an existing underperforming full-scale wastewater treatment plant (WWTP built for biological nutrient removal. The WWTP is operated in a 3-stage pho-redox process configuration (A2O. This study was undertaken with the aim of finding optimal operating conditions that will meet TP and TN concentration requirements in the effluent of the WWTP under study without the use of either chemical or external carbon sources and also to verify the applicability, capability and predictability of ASM2 as implemented in STOAT software. ASM2 was successfully used to troubleshoot bottle neck areas and to define the operational schedule for optimal performance of the wastewater treatment plant. Consequently, the costs of chemical and external carbon sources were eliminated and the effect of residual chemicals on the environment reduced.

  19. Demonstrating Compliance with Stringent Nitrogen Limits Using a Biological Nutrient Removal Process in California's Central Valley. (United States)

    Merlo, Rion; Witzgall, Bob; Yu, William; Ohlinger, Kurt; Ramberg, Steve; De Las Casas, Carla; Henneman, Seppi; Parker, Denny


    The Sacramento Regional County Sanitation District (District) must be compliant with stringent nitrogen limits by 2021 that the existing treatment facilities cannot meet. An 11-month pilot study was conducted to confirm that these limits could be met with an air activated sludge biological nutrient removal (BNR) process. The pilot BNR treated an average flow of 946 m(3)/d and demonstrated that it could reliably meet the ammonia limit, but that external carbon addition may be necessary to satisfy the nitrate limit. The BNR process performed well throughout the 11 months of operation with good settleability, minimal nocardioform content, and high quality secondary effluent. The BNR process was operated at a minimum pH of 6.4 with no noticeable impact to nitrification rates. Increased secondary sludge production was observed during rainfall events and is attributed to a change in wastewater influent characteristics.

  20. Benchmarking biological nutrient removal in wastewater treatment plants: influence of mathematical model assumptions. (United States)

    Flores-Alsina, Xavier; Gernaey, Krist V; Jeppsson, Ulf


    This paper examines the effect of different model assumptions when describing biological nutrient removal (BNR) by the activated sludge models (ASM) 1, 2d & 3. The performance of a nitrogen removal (WWTP1) and a combined nitrogen and phosphorus removal (WWTP2) benchmark wastewater treatment plant was compared for a series of model assumptions. Three different model approaches describing BNR are considered. In the reference case, the original model implementations are used to simulate WWTP1 (ASM1 & 3) and WWTP2 (ASM2d). The second set of models includes a reactive settler, which extends the description of the non-reactive TSS sedimentation and transport in the reference case with the full set of ASM processes. Finally, the third set of models is based on including electron acceptor dependency of biomass decay rates for ASM1 (WWTP1) and ASM2d (WWTP2). The results show that incorporation of a reactive settler: (1) increases the hydrolysis of particulates; (2) increases the overall plant's denitrification efficiency by reducing the S(NOx) concentration at the bottom of the clarifier; (3) increases the oxidation of COD compounds; (4) increases X(OHO) and X(ANO) decay; and, finally, (5) increases the growth of X(PAO) and formation of X(PHA,Stor) for ASM2d, which has a major impact on the whole P removal system. Introduction of electron acceptor dependent decay leads to a substantial increase of the concentration of X(ANO), X(OHO) and X(PAO) in the bottom of the clarifier. The paper ends with a critical discussion of the influence of the different model assumptions, and emphasizes the need for a model user to understand the significant differences in simulation results that are obtained when applying different combinations of 'standard' models.

  1. Experimental investigation of the external nitrification biological nutrient removal activated sludge (ENBNRAS) system. (United States)

    Hu, Zhi-Rong; Sötemann, S; Moodley, R; Wentzel, M C; Ekama, G A


    A systematic lab-scale experimental investigation is reported for the external nitrification (EN) biological nutrient removal (BNR) activated sludge (ENBNRAS) system, which is a combined fixed and suspended medium system. The ENBNRAS system was proposed to intensify the treatment capacity of BNR-activated sludge (BNRAS) systems by addressing two difficulties often encountered in practice: (a) the long sludge age for nitrification requirement; and (b) sludge bulking. In the ENBNRAS system, nitrification is transferred from the aerobic reactor in the suspended medium activated sludge system to a fixed medium nitrification system. Thus, the sludge age of the suspended medium activated sludge system can be reduced from 20 to 25 days to 8 to 10 days, resulting in a decrease in reactor volume per ML wastewater treated of about 30%. Furthermore, the aerobic mass fraction can also be reduced from 50% to 60% to 55% (if the anaerobic mass fraction is 15%), and thus complete denitrification in the anoxic reactors becomes possible. Research indicates that both the short sludge age and complete denitrification could ameliorate anoxic aerobic (AA) or low food/microorganism (F/M) ratio filamentous bulking, and hence reduce the surface area of secondary settling tanks or increase the treatment capacity of existing systems. The lab-scale experimental investigations indicate that the ENBNRAS system can obtain: (i) very good chemical oxygen demand (COD) removal, even with an aerobic mass fraction as low as 20%; (ii) high nitrogen removal, even for a wastewater with a high total kjeldahl nitrogen (TKN)/COD ratio, up to 0.14; (iii) adequate settling sludge (diluted sludge volume index [DSVI] <100 mL/g); and (iv) a significant reduction in oxygen demand.

  2. Application of Moving Bed Biofilm Process for Biological Organics and Nutrients Removal from Municipal Wastewater

    Directory of Open Access Journals (Sweden)

    M. Kermani


    Full Text Available In this study, experiments have been conducted to evaluate the organics and nutrients removal from synthetic wastewater by a laboratory scale moving bed biofilm process. For nutrients removal, moving bed biofilm process has been applied in series with anaerobic, anoxic and aerobic units in four separate reactors. Moving bed biofilm reactors were operated continuously at different loading rates of nitrogen and Phosphorus. During optimum conditions, close to complete nitrification with average ammonium removal efficiency of 99.72% occurred in the aerobic reactor. In the aerobic reactor, the average specific nitrification rate was 1.8 g NOx-N kg VSS-1 h-1. The results of the average effluent soluble COD concentration from each reactor showed that denitrification process in the second anoxic reactor consumed most of the biodegradable organic matter. As seen from the results, denitrification rate has increased with increasing NOx-N loading in the second anoxic reactor. The aerobic phosphate removal rate showed a good correlation to the anaerobic phosphate release rate. Moreover, phosphate removal rate showed a strong correlation to the phosphate loading rate in the aerobic reactor. In optimum conditions, the average SCOD, total nitrogen and phosphorus removal efficiencies were 96.9, 84.6 and 95.8%, respectively. This study showed that the moving bed biofilm process could be used as an ideal and efficient option for the total nutrient removal from municipal wastewater.

  3. Feasibility of hydraulic separation in a novel anaerobic-anoxic upflow reactor for biological nutrient removal. (United States)

    Díez-Montero, Rubén; De Florio, Loredana; González-Viar, Marta; Volcke, Eveline I P; Tejero, Iñaki


    This contribution deals with a novel anaerobic-anoxic reactor for biological nutrient removal (BNR) from wastewater, termed AnoxAn. In the AnoxAn reactor, the anaerobic and anoxic zones for phosphate removal and denitrification are integrated in a single continuous upflow sludge blanket reactor, aiming at high compactness and efficiency. Its application is envisaged in those cases where retrofitting of existing wastewater treatment plants for BNR, or the construction of new ones, is limited by the available surface area. The environmental conditions are vertically divided up inside the reactor with the anaerobic zone at the bottom and the anoxic zone above. The capability of the AnoxAn configuration to establish two hydraulically separated zones inside the single reactor was assessed by means of hydraulic characterization experiments and model simulations. Residence time distribution (RTD) experiments in clean water were performed in a bench-scale (48.4 L) AnoxAn prototype. The required hydraulic separation between the anaerobic and anoxic zones, as well as adequate mixing in the individual zones, were obtained through selected mixing devices. The observed behaviour was described by a hydraulic model consisting of continuous stirred tank reactors and plug-flow reactors. The impact of the denitrification process in the anoxic zone on the hydraulic separation was subsequently evaluated through model simulations. The desired hydraulic behaviour proved feasible, involving little mixing between the anaerobic and anoxic zones (mixing flowrate 40.2 % of influent flowrate) and negligible nitrate concentration in the anaerobic zone (less than 0.1 mgN L(-1)) when denitrification was considered.

  4. The stoichiometric ratio during biological removal of inorganic carbon and nutrient in the Mississippi River plume and adjacent continental shelf

    Directory of Open Access Journals (Sweden)

    W.-J. Huang


    Full Text Available The stoichiometric ratios of dissolved inorganic carbon (DIC and nutrients during biological removal have been widely assumed to follow the Redfield ratios (especially the C/N ratio in large river plume ecosystems. However, this assumption has not been systematically examined and documented because DIC and nutrients are rarely studied simultaneously in a river plume area, a region in which they can be affected by strong river-ocean mixing as well as intense biological activity. We examined stoichiometric ratios of DIC, total alkalinity (TA, and nutrients (NO3, PO43− and Si(OH4 data during biological removal in the Mississippi River plume and adjacent continental shelf in June 2003 and August 2004 with biological removals defined as the difference between measured values and values predicted on the basis of conservative mixing determined using a multi-endmember mixing model. Despite complex physical and biogeochemical influences, relationships between DIC and nutrients were strongly dependent on salinity range and geographic location, and influenced by biological removal. Lower C/Si and N/Si ratios in one nearshore area were attributed to a potential silicate source induced by water exchange with coastal salt marshes. When net biological uptake was separated from river-ocean mixing and the impact of marshes and bays excluded, stoichiometric ratios of C/N/Si were similar to the Redfield ratios, thus supporting the applicability of the Redfield-type C/N/Si ratios as a principle in river-plume biogeochemical models.

  5. Simultaneous nutrients and carbon removal from low-strength domestic wastewater with an immobilised-microorganism biological aerated filter. (United States)

    Chen, Q; Qu, L; Tong, G; Ni, J


    To improve the efficiency of low-strength domestic wastewater treatment, an immobilised-microorganism biological aerated filter (I-BAF) was established for simultaneous carbon, nitrogen and phosphorus removal. The I-BAF performance was systematically evaluated under continuous and intermittent aeration modes. At the optimal condition with an intermittent aeration control schedule of 2 h on/1 h off, the maximum removal rates of COD, NH(4)(+)-N, TN and P were 82.54%, 94.83%, 51.85% and 61.49%, respectively, and the corresponding averaged effluents could meet the first class standards of China. Further analysis of PCR-DGGE profile revealed that members of the gamma and alpha proteobacterium bacterial groups were probably responsible for the nitrogen and phosphorus removal. The I-BAF system showed excellent performance in carbon and nutrients removal, which provided a cost-effective solution for the treatment of low-strength domestic wastewater.

  6. Enhanced biological nutrient removal by the alliance of a heterotrophic nitrifying strain with a nitrogen removing ecosystem

    Institute of Scientific and Technical Information of China (English)


    and COD, respectively. These results suggest that it was more efficient for both the ammonia and carbon nutrient removals in a reactor inoculated with a heterotrophic nitrifier at high Corg/N ratio, inferring that the heterotrophic nitrifers would be practically more available in the treatment of wastewater with high level of ammonia and COD.

  7. Enhanced biological nutrient removal in modified carbon source division anaerobic anoxic oxic process with return activated sludge pre-concentration☆

    Institute of Scientific and Technical Information of China (English)

    Qin Lu; Haiyan Wu; Haoyan Li; Dianhai Yang


    A pilot-scale modified carbon source division anaerobic anoxic oxic (AAO) process with pre-concentration of returned activated sludge (RAS) was proposed in this study for the enhanced biological nutrient removal (BNR) of municipal wastewater with limited carbon source. The influent carbon source was fed in step while a novel RAS pre-concentration tank was adopted to improve BNR efficiency, and the effects of an influent carbon source distribution ratio and a RAS pre-concentration ratio were investigated. The results show that the removal efficiency of TN is mainly influenced by the carbon source distribution ratio while the TP removal relies on the RAS pre-concentration ratio. The optimum carbon source distribution ratio and RAS pre-concentration ratio are 60%and 50%, respectively, with an inner recycling ratio of 100%under the optimum steady operation of pilot test, reaching an average effluent TN concentration of 9.8 mg·L−1 with a removal efficiency of 63%and an average TP removal efficiency of 94%. The mechanism of nutrient removal is discussed and the kinetics is analyzed. The results reveal that the optimal carbon source distribution ratio provides sufficient denitrifying carbon source to each anoxic phase, reducing nitrate accumulation while the RAS pre-concentration ratio improves the condition of anaerobic zone to ensure the phosphorus release due to less nitrate in the returned sludge. Therefore, nitrifying bacteria, denitrifying bacteria and phosphorus accumulation organisms play an important role under the optimum condition, enhancing the performance of nutrient removal in this test.

  8. Removal of organics and nutrients from food wastewater using combined thermophilic two-phase anaerobic digestion and shortcut biological nitrogen removal. (United States)

    Cui, Fenghao; Lee, Seungho; Kim, Moonil


    A process combining pilot-scale two-phase anaerobic digestion and shortcut biological nitrogen removal (SBNR) was developed to treat organics and nutrients (nitrogen and phosphorus) from food wastewater. The thermophilic two-phase anaerobic digestion process was investigated without adjusting the pH of the wastewater for the pre-acidification process. The digested food wastewater was treated using the SBNR process without supplemental carbon sources or alkalinity. Under these circumstances, the combined system was able to remove about 99% of COD, 88% of TN, and 97% of TP. However, considerable amounts of nutrients were removed due to chemical precipitation processes between the anaerobic digestion and SBNR. The average TN removal efficiency of the SBNR process was about 74% at very low C/N (TCOD/TN) ratio of 2. The SBNR process removed about 39% of TP from the digested food wastewater. Conclusively, application of the combined system improved organic removal efficiency while producing valuable energy (biogas), removed nitrogen at a low C/N ratio, and conserved additional resources (carbon and alkalinity).

  9. Enhanced Nutrient Removal with Upflow Biological Aerated Filter for Reclaimed Water

    Institute of Scientific and Technical Information of China (English)

    WANG Hai-dong; PENG Yong-zhen; WANG Shu-ying; ZHANG Yan-ping


    A two-stage upflow biological aerated filter was designed as an advanced treatment process to optimize the operating parameters and study the correlative factors influencing the efficiency of nitrification, denitrification and phosphorus removal. The experimental results showed that the final effluent of the two-stage upflow biofilter process operated in series could meet the stringent limits of the reclaimed water for the total nitrogen of 2mg/L, and total phosphorus of 0.3mg/L. The high treatment efficiency allowed the reactor operating at very high hydraulic loadings and reaching nearly complete nitrification and denitrification.

  10. Strategies for achieving energy neutrality in biological nutrient removal systems - a case study of the Slupsk WWTP (northern Poland). (United States)

    Zaborowska, Ewa; Czerwionka, Krzysztof; Makinia, Jacek


    The paper presents a model-based evaluation of technological upgrades on the energy and cost balance in a large biological nutrient removal (BNR) wastewater treatment plant (WWTP) in the city of Slupsk (northern Poland). The proposed upgrades include chemically enhanced primary sludge removal and reduction of the nitrogen load in the deammonification process employed for reject water treatment. Simulations enabled to estimate the increased biogas generation and decreased energy consumption for aeration. The proposed upgrades may lead the studied WWTP from the energy deficit to energy neutrality and positive cost balance, while still maintaining the required effluent standards for nitrogen. The operating cost balance depends on the type of applied coagulants/flocculants and specific costs of electric energy. The choice of the coagulant/flocculent was found as the main factor determining a positive cost balance.

  11. Comparative modeling of biological nutrient removal from landfill leachate using a circulating fluidized bed bioreactor (CFBBR). (United States)

    Eldyasti, Ahmed; Andalib, Mehran; Hafez, Hisham; Nakhla, George; Zhu, Jesse


    Steady state operational data from a pilot scale circulating fluidized bed bioreactor (CFBBR) during biological treatment of landfill leachate, at empty bed contact times (EBCTs) of 0.49, and 0.41 d and volumetric nutrients loading rates of 2.2-2.6 kg COD/(m(3)d), 0.7-0.8 kg N/(m(3)d), and 0.014-0.016 kg P/(m(3)d), was used to calibrate and compare developed process models in BioWin(®) and AQUIFAS(®). BioWin(®) and AQUIFAS(®) were both capable of predicting most of the performance parameters such as effluent TKN, NH(4)-N, NO(3)-N, TP, PO(4)-P, TSS, and VSS with an average percentage error (APE) of 0-20%. BioWin(®) underpredicted the effluent BOD and SBOD values for various runs by 80% while AQUIFAS(®) predicted effluent BOD and SBOD with an APE of 50%. Although both calibrated models, confirmed the advantages of the CFBBR technology in treating the leachate of high volumetric loading and low biomass yields due to the long solid retention time (SRT), both BioWin(®) and AQUIFAS(®) predicted the total biomass and SRT of CFBBR based on active biomass only, whereas in the CFBBR runs both active as well as inactive biomass accumulated.

  12. Biological nutrient removal from municipal wastewater in sequencing batch biofilm reactors

    Energy Technology Data Exchange (ETDEWEB)

    Arnz, P.


    Enhanced biological phosphorus removal (EBPR) has only been put into practice in activated sludge systems. In recent years, the Sequencing Batch Biofilm Reactor (SBBR) has emerged as an alternative allowing EBPR to be achieved in a biofilm reactor. High efficiency of phosphate removal was demonstrated in a SBBR fed with synthetic wastewater containing acetate. The aim of this study was to investigate EBPR from municipal wastewater in semi full-scale and laboratory-scale SBBRs. The focus of the investigation in the semi full-scale reactor was on determination of achievable reaction rates and effluent concentrations under varying influent conditions throughout all seasons of a year. Interactions between nitrogen and phosphorus removal and the influence of backwashing on the reactor performance was examined. Summing up, it can be stated that the SBBR proved to be an attractive alternative to activated sludge systems. Phosphorus elimination efficiency was comparable to common systems but biomass sedimentation problems were avoided. In order to further exploit the potential of the SBBR and to achieve reactor performances superior to those of existing systems designing a special biofilm carrier material may allow to increase the phenomenon of simultaneous nitrification/denitrification while maintaining EBPR activity. (orig.) [German] Die vermehrte biologische Phosphorelimination (Bio-P) aus Abwasser wurde bisher nur in Belebtschlammsystemen praktiziert. In den letzten Jahren konnte jedoch gezeigt werden, dass sich durch die Anwendung des Sequencing Batch Biofilm Reactor (SBBR) - Verfahrens auch in Biofilmreaktoren Bio-P verwirklichen laesst. Versuche in Laboranlagen haben ergeben, dass sich eine weitgehende Phosphorelimination aufrecht erhalten laesst, wenn die Reaktoren mit einem ideal zusammengesetzten, synthetischen Abwasser beschickt werden. Ziel dieser Arbeit war es, Bio-P aus kommunalem Abwasser in SBBR-Versuchsanlagen im halbtechnischen und im Labormassstab zu

  13. Biological nutrients removal from the supernatant originating from the anaerobic digestion of the organic fraction of municipal solid waste. (United States)

    Malamis, S; Katsou, E; Di Fabio, S; Bolzonella, D; Fatone, F


    This study critically evaluates the biological processes and techniques applied to remove nitrogen and phosphorus from the anaerobic supernatant produced from the treatment of the organic fraction of municipal solid waste (OFMSW) and from its co-digestion with other biodegradable organic waste (BOW) streams. The wide application of anaerobic digestion for the treatment of several organic waste streams results in the production of high quantities of anaerobic effluents. Such effluents are characterized by high nutrient content, because organic and particulate nitrogen and phosphorus are hydrolyzed in the anaerobic digestion process. Consequently, adequate post-treatment is required in order to comply with the existing land application and discharge legislation in the European Union countries. This may include physicochemical and biological processes, with the latter being more advantageous due to their lower cost. Nitrogen removal is accomplished through the conventional nitrification/denitrification, nitritation/denitritation and the complete autotrophic nitrogen removal process; the latter is accomplished by nitritation coupled with the anoxic ammonium oxidation process. As anaerobic digestion effluents are characterized by low COD/TKN ratio, conventional denitrification/nitrification is not an attractive option; short-cut nitrogen removal processes are more promising. Both suspended and attached growth processes have been employed to treat the anaerobic supernatant. Specifically, the sequencing batch reactor, the membrane bioreactor, the conventional activated sludge and the moving bed biofilm reactor processes have been investigated. Physicochemical phosphorus removal via struvite precipitation has been extensively examined. Enhanced biological phosphorus removal from the anaerobic supernatant can take place through the sequencing anaerobic/aerobic process. More recently, denitrifying phosphorus removal via nitrite or nitrate has been explored. The removal of

  14. Nutrient Removal in Wastewater Treatment (United States)

    Shah, Kanti L.


    Discusses the sources and effects of nutrients in wastewater, and the methods of their removal in wastewater treatment. In order to conserve water resources and eliminate the cost of nutrient removal, treated effluent should be used wherever possible for irrigation, since it contains all the ingredients for proper plant growth. (JR)

  15. A modified UCT method for biological nutrient removal: configuration and performance. (United States)

    Vaiopoulou, E; Aivasidis, A


    A pilot-scale prototype activated sludge system is presented, which combines both, the idea of University of Cape Town (UCT) concept and the step denitrification cascade for removal of carbon, nitrogen and phosphorus. The experimental set-up consists of an anaerobic selector and stepwise feeding in subsequent three identical pairs of anoxic and oxic tanks. Raw wastewater with influent flow rates ranging between 48 and 168 l d(-1) was fed to the unit at hydraulic residence times (HRTs) of 5-18 h and was distributed at percentages of 60/25/15%, 40/30/30% and 25/40/35% to the anaerobic selector, 2nd and 3rd anoxic tanks, respectively (influent flow distribution before the anaerobic selector). The results for the entire experimental period showed high removal efficiencies of organic matter of 89% as total chemical oxygen demand removal and 95% removal for biochemical oxygen demand, 90% removal of total Kjeldahl nitrogen and total nitrogen removal through denitrification of 73%, mean phosphorus removal of 67%, as well as excellent settleability. The highest removal efficiency and the optimum performance were recorded at an HRT of about 9h and influent flow rate of 96 l d(-1), in which 60% is distributed to the anaerobic selector, 25% to the second anoxic tank and 15% to the last anoxic tank. Consequently, the plant configuration enhanced removal efficiency, optimized performance, saved energy, formed good settling sludge and provided operational assurance.

  16. High rate biological nutrient removal from high strength wastewater using anaerobic-circulating fluidized bed bioreactor (A-CFBBR). (United States)

    Andalib, Mehran; Nakhla, George; Zhu, Jesse


    Biological nutrient removal (BNR) from high strength wastewater was investigated using a newly developed integrated anaerobic fluidized bed (AF) with circulating fluidized bed bioreactor henceforth called A-CFBBR. The A-CFBBR showed 99.7%COD removal, 84% nitrogen removal, with a very low sludge yield of 0.017 g VSS/g COD while treating a synthetic wastewater containing 10,700 mg COD/L and 250 mg NH(3)-N/L over a period of 6 months. The system was operated at an organic loading rate (OLR) of 35 kg COD/m(3)(AF) d and nitrogen loading rate (NLR) of 1.1 kg N/m(3)(CFBBR) d at a hydraulic retention time (HRT) of less than 12 h in the A-CFBBR. Microbial communities analysis using DGGE confirmed the presence of both AOBs and NOBs in the riser and downer. Pseudomonas putida and Pseudomonas fluorescence were the dominant denitrifiers present in the downer. Methanogenic activity was accomplished by a microbial mixture of archaea and bacteria in the anaerobic column.

  17. Evaluation of biological nutrient removal from wastewater by Twin Circulating Fluidized Bed Bioreactor (TCFBBR) using a predictive fluidization model and AQUIFAS APP. (United States)

    Andalib, Mehran; Nakhla, George; Sen, Dipankar; Zhu, Jesse


    A two-phase and three-phase predictive fluidization model based on the characteristics of a system such as media type and size, flow rates, and reactor cross sectional area was proposed to calculate bed expansion, solid, liquid and gas hold up and specific surface area (SSA) of the biofilm particles. The model was subsequently linked to 1d AQUIFAS APP software (Aquaregen) to model biological nutrient removal in two phase (anoxic) and three phase (aerobic) fluidized bed bioreactors. The credibility of the proposed model for biological nutrient removal was investigated using the experimental data from a Twin Circulating Fluidized Bed Bioreactors (TCFBBR) treating synthetic and municipal wastewater. The SSA of bio-particles and volume of the expanded bed were simulated as a function of operational parameters. Two-sided t-tests demonstrated that simulated SCOD, NH(4)-N, NO(3)-N, TN, VSS and biomass yields agreed with the experimental values at the 95% confidence level.

  18. Removal of nutrients in denitrification system using coconut coir fibre for the biological treatment of aquaculture wastewater. (United States)

    Manoj, Valsa Remony; Vasudevan, Namasivayam


    Ideal bacterial support medium for fixed film denitrification processes/bioreactors must be inexpensive, durable and possess large surface area with sufficient porosity. The present study has been focussed on removing nitrate nitrogen at two different nitrate nitrogen loading rates (60 (NLR I) and 120 (NLR II) mg l(-1)) from simulated aquaculture wastewater. Coconut coir fibre and a commercially available synthetic reticulated plastic media (Fujino Spirals) were used as packing medium in two independent upflow anaerobic packed bed column reactors. Removal of nitrate nitrogen was studied in correlation with other nutrients (COD, TKN, dissolved orthophosphate). Maximum removal of 97% at NLR-I and 99% at NLR - II of nitrate nitrogen was observed in with either media. Greater consistency in the case of COD removal of upto 81% was observed at NLR II where coconut coir was used as support medium compared to 72% COD removal by Fujino Spirals. The results observed indicate that the organic support medium is just as efficient in nitrate nitrogen removal as conventionally used synthetic support medium. The study is important as it specifically focuses on denitrification of aquaculture wastewater using cheaper organic support medium in anoxic bioreactors for the removal of nitrate nitrogen; which is seldom addressed as a significant problem.

  19. Combined Pre-Precipitation, Biological Sludge Hydrolysis and Nitrogen Reduction - A Pilot Demonstration of Integrated Nutrient Removal

    DEFF Research Database (Denmark)

    Kristensen, G. H.; Jørgensen, P. E.; Strube, R.


    A pilot study was performed to investigate advanced wastewater treatment by pre-precipitation in combination with biological nitrogen removal supported by biological sludge hydrolysis. The influent wastewater was pretreated by addition of a pre-polymerized aluminum salt, followed by flocculation...... solubilization was 10-13% of the suspended COD. The liquid phase of the hydrolyzed sludge, the hydrolysate, was separated from the suspended fraction by centrifugation and added to the biological nitrogen removal stage to support denitrification. The hydrolysate COD consisted mainly of volatile fatty acids......, resulting in high denitrification rates. Nitrogen reduction was performed based on the Bio-Denitro principle in an activated sludge system. Nitrogen was reduced from 45 mg/l to 9 mg/l and phosphorus was reduced from 11 mg/l to 0.5 mg/l. The sludge yield was low, approx. 0.3-0.4 gCOD/gCOD removed...

  20. Pilot-scale experience with biological nutrient removal and biomass yield reduction in a liquid-solid circulating fluidized bed bioreactor. (United States)

    Chowdhury, Nabin; Nakhla, George; Zhu, Jesse; Islam, Mohammad


    A pilot-scale liquid-solid circulating fluidized bed (LSCFB) bioreactor was developed at the Adelaide Pollution Control Plant, London, Ontario, Canada, to study its commercial viability for biological nutrient removal. Lava rock particles of 600 microm were used as a biomass carrier media. The LSCFB removed approximately 90% organic, 80% nitrogen, and 70% phosphorus at loading rates of 4.12 kg COD/m3 x d, 0.26 kg N/m3 x d, and 0.052 kg P/m3 x d, and an empty bed contact time of 1.5 hours. Effluent characterized by < 1.0 mg NH4-N/L, < 5.0 mg NO3-N/ L, < 1.0 mg PO4-P/L, < 10 mg TN/L, < 10 mg SBOD/L, and 10 to 15 mg volatile suspended solids (VSS)/L can easily meet the criteria for nonpotable reuse of treated wastewater. The system removed nutrients without using any chemicals, and the secondary clarifier removed suspended solids removal without chemicals. A significant reduction (approximately 75%) in biomass yield to 0.12 to 0.16 g VSS/g chemical oxygen demand (COD) was observed, primarily because of long biological solids retention time (SRT) of 20 to 39 days and a combination of anoxic and aerobic COD consumption.

  1. Biological wastewater treatment. II Nutrient elimination; Tratamiento biologico de aguas residuales. II Eliminacion de nutrientes

    Energy Technology Data Exchange (ETDEWEB)

    Arnaiz, C.; Isac, L.; Lebrato, J. [Universidad de Sevilla (Spain)


    Most biological wastewater processes are designed for carbonaceous compounds removal. In some cases, nutrient removal is required. In this work, biodiversity and microbial interactions of nitrogen and phosphorus removal are described. (Author) 12 refs.

  2. Outcomes of a 2-year investigation on enhanced biological nutrients removal and trace organics elimination in membrane bioreactor (MBR). (United States)

    Lesjean, B; Gnirss, R; Buisson, H; Keller, S; Tazi-Pain, A; Luck, F


    Two configurations of membrane bioreactors were identified to achieve enhanced biological phosphorus and nitrogen removal, and assessed over more than two years with two parallel pilot plants of 2m3 each. Both configurations included an anaerobic zone ahead of the biological reactor, and differed by the position of the anoxic zone: standard pre-denitrification, or post-denitrification without dosing of carbon source. Both configurations achieved improved phosphorus removal. The goal of 50 microgP/L in the effluent could be consistently achieved with two types of municipal wastewater, the second site requiring a low dose of ferric salt ferric salt eliminated for 10 mg BOD5 in the influent. The post-denitrification configuration enabled a very good elimination of nitrogen. Daily nitrate concentration as low as 1 mgN/L could be monitored in the effluent in some periods. The denitrification rates, greater than those expected for endogenous denitrification, could be accounted for by the use of the glycogene pool, internally stored by the denitrifying microorganisms in the anaerobic zone. Pharmaceuticals residues and steroids were regularly monitored on the two parallel MBR pilot plants during the length of the trials, and compared with the performance of the Berlin-Ruhleben WWTP. Although some compounds such as carbamazepine were persistent through all the systems, most of the compounds could be better removed by the MBR plants. The influence of temperature, sludge age and compound concentration could be shown, as well as the significance of biological mechanisms in the removal of trace organic compounds.

  3. Biological nutrient removal with low nitrous oxide generation by cancelling the anaerobic phase and extending the idle phase in a sequencing batch reactor. (United States)

    Chen, Yinguang; Wang, Dongbo; Zheng, Xiong; Li, Xiang; Feng, Leiyu; Chen, Hong


    Although wastewater biological nutrient removal can be achieved by alternating the anaerobic-oxic-anoxic phases, significant amount of nitrous oxide (N2O) is generated in oxic phases, where ammonia-oxidizing bacteria (AOB) rather than heterotrophic denitrifiers are the main contributors. Here a new efficient strategy to remarkably reduce N2O generation was reported. It was found that by cancelling the anaerobic phase and extending the idle phase the N2O generation was reduced by 42% using synthetic wastewater, whereas the total nitrogen and phosphorus removals were unaffected. The mechanistic investigations revealed that the cancelling of anaerobic phase benefited heterotrophic denitrifiers instead of AOB to be responsible for nitrogen removal in the oxic phases, increased the ratio of total nitrogen removal driven by external carbon source, and decreased nitrite accumulation. Quantitative real-time polymerase chain reaction and fluorescence in situ hybridization analyses further showed that the new strategy increased the number of N2O reducing bacteria but decreased the abundance of glycogen accumulating organisms, with N2O as their primary denitrification product. It was also determined that the ratio of nitric oxide reductase activity to N2O reductase activity was significantly decreased after anaerobic phase was cancelled. All these observations were in accord with the reduction of N2O production. The feasibility of this strategy to minimize the generation of N2O was finally confirmed for a real municipal wastewater. The results reported in this paper provide a new viewpoint to reduce N2O generation from wastewater biological nutrient removal.

  4. Biological Nutrient Removal in a Full Scale Anoxic/Anaerobic/Aerobic/Pre-anoxic-MBR Plant for Low C/N Ratio Municipal Wastewater Treatment

    Institute of Scientific and Technical Information of China (English)

    胡香; 谢丽; 张善发; 杨殿海


    A novel full scale modified A2O (anoxic/anaerobic/aerobic/pre-anoxic)-membrane bioreactor (MBR) plant combined with the step feed strategy was operated to improve the biological nutrient removal (BNR) from low C/N ratio municipal wastewater in Southern China. Transformation of organic carbon, nitrogen and phosphorus, and membrane fouling were investigated. Experimental results for over four months demonstrated good efficiencies for chemical oxygen demand (COD) and 4NH+-N removal, with average values higher than 84.5%and 98.1%, re-spectively. A relatively higher total nitrogen (TN) removal efficiency (52.1%) was also obtained at low C/N ratio of 3.82, contributed by the configuration modification (anoxic zone before anaerobic zone) and the step feed with a distribution ratio of 1︰1. Addition of sodium acetate into the anoxic zone as the external carbon source, with a theoretical amount of 31.3 mg COD per liter in influent, enhanced denitrification and the TN removal efficiency in-creased to 74.9%. Moreover, the total phosphate (TP) removal efficiency increased by 18.0%. It is suggested that the external carbon source is needed to improve the BNR performance in treating low C/N ratio municipal waste-water in the modified A2O-MBR process.

  5. Integrated real-time control strategy in multi-tank A2O process for biological nutrient removal treating real domestic wastewater

    Directory of Open Access Journals (Sweden)

    Saad Abualhail


    Full Text Available An integrated real-time anaerobic–anoxic/oxic (A2O operated with multi-tank called IMT–A2O process was designed and operated with fluctuating influent loads for biological nutrient removal for treating real domestic wastewater. IMT–A2O process, a “phased isolation tank” technology, varies both aeration pattern and flow path in a continuous flow multi-tank system to force fluctuation of organic and nutrient concentrations in process reactors. Using an eight-phase cycle, desired biochemical transformations, are accomplished at different times in the same tank. On-line sensors (pH, ORP, and DO were used as real-time control parameters to adjust the duration of each operational phase in the IMT–A2O process. The control system is an algorithm that automatically adjusts the cycle length to the influent wastewater characteristics according to the end points. It was found that on-line sensor values of pH, ORP, and DO were somehow related with the dynamic behaviors of nutrient concentrations in IMT–A2O. The algorithm acts in the reaction phases of the IMT–A2O cycle using ORP and pH break points of tank one to distinguish the end of denitrification and the beginning of phosphorus release, pH break point of tank two to control the end of denitrification and beginning of phosphorus release and a sudden increase in DO pattern, pH break point and ORP to control phosphorus uptake and the end of the nitrification process. Although the fluctuations in raw wastewater concentration are extreme; an influent with a low C/N ratio is deficient in organic carbon, and a low carbon source level can limit the overall biological denitrification process, the average removal efficiencies achieved for COD, ammonia–nitrogen, total nitrogen and total phosphorus were not less than 76.11%, 87.78%, 76.45% and 83.75%, respectively, using the integrated real-time control strategy. The integrated IMT–A2O exhibited a better performance in nutrient removal than the

  6. Enhanced biological nutrients removal using an integrated oxidation ditch with vertical circle from wastewater by adding an anaerobic column

    Institute of Scientific and Technical Information of China (English)

    WANG Shu-mei; LIU Jun-xin


    Compared to conventional oxidation ditches, an integrated oxidation ditch with vertical circle(IODVC) has the characters of concise configuration, simple operation and maintenance, land saving and automatical sludge returning. By the utilization of vertical circulation, an aerobic zone and an anoxic zone can be unaffectedly formed in the IODVC. Therefore, COD and nitrogen can be efficiently removed. However, the removal efficiency of phosphorus was Iow in the IODVC. In the experiment described, a laboratory scale system to add an anaerobic column to the IODVC has been tested to investigate the removal of phosphorus from wastewater. The experimental results showed that the removal efficiency of TP with the anaerobic column was increased to 54.0 % from 22.3 % without the anaerobic column. After the acetic sodium was added into the influent as carbon sources, the mean TP removal efficency of 77.5 % was obtained. At the same time, the mean removal efficiencies of COD, TN and NH3-N were 92.2%, 81.6% and 98.1%, respectively, at 12 h of HRT and 21-25 d of SRT. The optimal operational conditions in this study were as follows: recycle rate = 1.5-2.0, COD/TN > 6, COD/TP > 40,COD loading rate = 0.26-0.32 kgCOD/(kgSS·d), TN loading rate =0.028-0.034 kgTN/(kgSS·d) and TP loading rate = 0.003-0.005kgTP/(kgSS·d), respectively.

  7. Nutrients removal and recovery in bioelectrochemical systems: a review. (United States)

    Kelly, Patrick T; He, Zhen


    Nutrient removal and recovery has received less attention during the development of bioelectrochemical systems (BES) for energy efficient wastewater treatment, but it is a critical issue for sustainable wastewater treatment. Both nitrogen and phosphorus can be removed and/or recovered in a BES through involving biological processes such as nitrification and bioelectrochemical denitrification, the NH4(+)/NH3 couple affected by the electrolyte pH, or precipitating phosphorus compounds in the high-pH zone adjacent a cathode electrode. This paper has reviewed the nutrients removal and recovery in various BES including microbial fuel cells and microbial electrolysis cells, discussed the influence factors and potential problems, and identified the key challenges for nitrogen and phosphorus removal/recovery in a BES. It expects to give an informative overview of the current development, and to encourage more thinking and investigation towards further development of efficient processes for nutrient removal and recovery in a BES.

  8. Plant Leachate Nutrient Recovery with Biological, Thermal, and Photocatalytic Pretreatments (United States)

    Wong, Les


    Plants are ideal for long term space travel: provide essential resources - oxygen, water, food; Water-soaked plants expel soluble nutrients in a leachate solution - toxins and wastes are also expelled and inhibit growth; biological, thermal, photocatalytic coupled with an acid digestion treatment will hopefully maximize recovery and remove wastes

  9. Phycoremediation of Wastewater: Heavy Metal and Nutrient Removal Processes

    Directory of Open Access Journals (Sweden)

    Kwarciak-Kozłowska Anna


    Full Text Available Phycoremediation is the use of algae for the removal or biotrans-formation of pollutants from wastewater. The study is a novel at-tempt to integrate nutrient (N and P removal and some heavy met-als (iron, manganese and zinc bioaccumulation from municipal wastewater using two microalgae species: Chlorella vulgaris and Scenedesmus armatus. The Chlorella vulgaris showed higher re-moval of total nitrogen (TN both in influent and effluent waste water than Scenedesmus armatus. Nevertheless, more than 51% of total phosphorus (TP in effluent and 36% in influent wastewaters were removed by Scenedesmus armatus. More efficient microalga in heavy metal removal in influent wastewater was Scenedesmus armatus. The results showed that Chlorella vulgaris was appropriate for TN removal and bioaccumulation of heavy metals from effluent wastewater. Nevertheless, Scenedesmus armatus was highly pref-erable for heavy metals removal from influent wastewater.

  10. Biological systems combined for the treatment of coffee processing wastewater: II - Removal of nutrients and phenolic compounds - doi: 10.4025/actascitechnol.v35i3.13628

    Directory of Open Access Journals (Sweden)

    Ronaldo Fia


    Full Text Available Three treatment systems consisting of anaerobic filters with upward flow followed by constructed wetland systems (CW were evaluated for the removal of nutrients and phenolic compounds, in the treatment of coffee processing wastewater (WCP in Viçosa, Minas Gerais State. Filters were made of PVC (1.5 m high and 0.35 m diameter filled with gravel # 2 and CW were made of wooden boxes (1.5 m long, 0.4 m high and 0.5 m wide sealed by HDPE geomembrane and filled with gravel ‘zero’. The WCP had the pH adjusted with lime to values close to 7.0 and the nutrient concentration changed to obtain a BOD/N/P ratio of 100/5/1. As a result, hydraulic retention times longer than 160 h in all treatment systems during phase III had not promoted greater efficiencies for removal compared with the phase I, because the recovery time of the systems was inadequate. The F1+CW1 system that received the lowest organic load, showed a satisfactory performance with regard to the removal of nutrients (above 50%.  

  11. 除磷系统剩余污泥中营养元素的快速释放及回收%Rapid Release and Recovery of Nutrient Elements in Excess Sludge from Biological Phosphorus Removal Process

    Institute of Scientific and Technical Information of China (English)

    王怡; 曲鹏程; 郑淑健; 彭党聪


    除磷系统的剩余污泥在浓缩、储存及后续的处理过程中均可能引起磷的释放,释放的磷往往导致正在运行的污水处理厂的磷负荷超标,最终引起出水磷的不稳定排放.针对此问题,在分析生物除磷系统剩余污泥化学特性的基础上,探讨除磷剩余污泥中营养元素的快速释放条件及磷回收效果.采用两个平行反应器,其中一个作为控制反应器,另一个添加表面活性剂十二烷基硫酸钠(SDS),在中温厌氧条件下对剩余污泥进行水解,并对水解产物中的营养元素在室温、pH值为9.5、搅拌转速为400 r/min的条件下进行鸟粪石回收.结果表明:生物除磷系统的剩余污泥具有磷含量高、磷释放快速、氮释放缓慢的特点;添加SDS不仅可以促进污泥水解过程中磷和氮的释放,而且对回收鸟粪石有积极作用;综合考虑水解产物中的氮、磷浓度及其比值和水解的时间成本,建议快速水解条件为添加SDS且水解24 h.%Excess sludge from biological phosphorus removal (BPR) process usually releases phosphorus when the sludge is thickened, stored and subsequently treated, which always leads to phosphorus overload in a running wastewater treatment plant and results in unstable discharge of effluent phosphorus. Based on the analysis of chemical characteristics of excess sludge from BPR process, the rapid release and recovery of nutrient elements in excess sludge were investigated. Bench-scale experiments of anaerobic hydrolysis under mesothermal condition were carried out in two identical reactors. One reactor served as control and the other was filled with sodium dodecyl sulfate (SDS). The nutrient elements in the hydrolysate were recovered by struvite crystallization under room temperature, pH value of 9.5 and mixing speed of 400 r/min. The results showed that excess sludge from BPR process was characterized by high phosphorus content, rapid release of phosphorus and slow release of

  12. Performance evaluation of a modified step-feed anaerobic/anoxic/oxic process for organic and nutrient removal

    Institute of Scientific and Technical Information of China (English)

    A.R. Majdi Nasab; S.M. Soleymani; M. Nosrati; S.M. Mousavi


    A pilot scale modified step-feed process was improved to increase nutrient (N and P) and organic removal operations from municipal wastewater. It combined the step-feed process and a method named“University of Cape Town (UCT)”. The effect of nutrient ratios and inflow distribution ratios were studied. The highest uptake efficiency of 95%for chemical oxygen demand (COD) has been achieved at the inflow distribution ratio of 40/35/25. However, maximum removal efficiency obtained for total nitrogen (TN) and phosphorus at 93%and 78%, respectively. The average mixed liquor suspended solids (MLSS) was 5500 mg·L−1. In addition, convenient values for dissolved oxygen (DO) concentration, and pH were obtained throughout different stages. The proposed system was identified to be an appropriate enhanced biological nutrient removal process for wastewater treatment plants owing to relatively high nutrient removal, sturdy sludge settle ability and COD removal.

  13. Enhanced Biological Nutrients Removal in Modified Step-feed Anaerobic/Anoxic/Oxic Process%改进型分段进水厌氧/缺氧/好氧工艺强化营养物去除

    Institute of Scientific and Technical Information of China (English)

    王伟; 王淑莹; 彭永臻; 张善锋; 殷芳芳


    In order to enhance phosphorus removal in traditional step-feed anoxic/oxic nitrogen removal process, a modified pilot-scale step-feed anaerobic/anoxic/oxic (SFA~2/O) system was developed, which combined a reactor similar to UCT-type configuration and two-stage anoxic/oxic process. The simultaneous nitrogen and phosphorus removal capacities and the potential of denitrifying phosphorus removal, in particular, were investigated with four different feeding patterns using real municipal wastewater. The results showed that the feeding ratios (Q_1) in the first stage determined the nutrient removal performance in the SFA~2/O system. The average phosphorus removal efficiency increased from 19.17% to 96.25% as Q_1 was gradually increased from run 1 to run 4, but the nitrogen removal efficiency exhibited a different tendency, which attained a maximum 73.61% in run 3 and then decreased to 59.62% in run 4. As a compromise between nitrogen and phosphorus removal, run 3 (Q_1 = 0.45Q_(total)) was identified as the optimal and stable case with the maximum anoxic phosphorus uptake rate of 1.58 mg(g MLSS)~(-1)·h~(-1). The results of batch tests showed that ratio of the anoxic phosphate uptake capacity to the aerobic phosphate uptake capacity increased from 11.96% to 36.85% with the optimal influent feeding ratio to the system in run 3, which demonstrated that the denitrifying polyP accumulating organisms could be accumulated and contributed more to the total phosphorus removal by optimizing the inflow ratio distribution. However, the nitrate recirculation to anoxic zone and influent feeding ratios should be carefully controlled for carbon source saving.

  14. Nutrient distribution in flowering stems, nutrient removal and fertilization of three proteaceae cultivars

    Directory of Open Access Journals (Sweden)

    M.M. Hernández


    Full Text Available Several parameters of flowering stems of two cultivars of protea Leucospermum cordifolium (Knight Fourc (‘Succession II’ and ‘Tango’ and one of protea Protea L. (Protea susannae x magnifica ‘Susara’ were studied in different commercial plantations. These included length and weight measures, nutrient concentrations of detached parts (flower heads, leaves and stems, and removal of nutrients of harvested flowers. A base for fertilization was also calculated. Harvested flowers of ‘Susara’ removed more P, K and Cu than ‘Succession II’ and ‘Tango’, and more Ca and Fe than ‘Tango’. ‘Succession II’ showed the highest Zn removal. The P and Cu removal by the crop of ‘Susara’ were significantly higher than those of both Leucospermum cultivars, while K, Ca, and Fe outputs of ‘Susara’ exceeded only those of ‘Tango’. The nutrient top removals amounted to 4.55 g m-2 of N, 0.48 g m-2 of P, and 5.26 g m-2 of K. Data as a base to supply fertilizer to each cultivar are given, with N:P:K ratios of 1:0.08:0.87 for ‘Succession II’, 1:0.08:0.83 for ‘Tango’ and 1:0.10:1.27 for ‘Susara’.

  15. Biological systems combined for the treatment of coffee processing wastewater: II - Removal of nutrients and phenolic compounds - doi: 10.4025/actascitechnol.v35i3.13628



    Three treatment systems consisting of anaerobic filters with upward flow followed by constructed wetland systems (CW) were evaluated for the removal of nutrients and phenolic compounds, in the treatment of coffee processing wastewater (WCP) in Viçosa, Minas Gerais State. Filters were made of PVC (1.5 m high and 0.35 m diameter) filled with gravel # 2 and CW were made of wooden boxes (1.5 m long, 0.4 m high and 0.5 m wide) sealed by HDPE geomembrane and filled with gravel ‘zero’. The WCP ...

  16. Determination of optimum conditions for dairy wastewater treatment in UAASB reactor for removal of nutrients. (United States)

    Amini, Malihe; Younesi, Habibollah; Lorestani, Ali Akbar Zinatizadeh; Najafpour, Ghasem


    In this study, the granular sludge was generated for simultaneous nitrification, denitrification and phosphorus removal (SNDPR) and studied on a laboratory scale. Analyzing the nutrients removal percentages from wastewater were scrutinized by using an optimization of the variables, i.e., COD:N:P ratio, OLR, aeration time, MLSS, F:M and HRT. These 6 interrelated parameters were evaluated as the process response. Microscopic observations of the performance of the SNDPR process revealed that the granules included Bacillus sp. in the bacterial community. According to these results, the UAASB system produced an effluent that lends dairy wastewater suitable for land irrigation and that this an attractive process of using granular sludge is appropriate for achieving carbon, nitrogen and phosphorus removal from nutrient-rich wastewater by a biological method.

  17. Biological removal of methanol from process condensate for the purpose of reclamation

    Institute of Scientific and Technical Information of China (English)

    WANG Yan-ming; YANG Min; ZHANG Yu; GAO Meng-chun; ZHANG Jing


    The biological removal of methanol from condensate of ammonia manufacturing processes for the purpose of reclamation using contact type reactor was studied. Methanol of 60 mg/L was removed completely under an HRT of 1.12 h. Optimal inorganic nutrient dose was determined on evaluating methanol removal performance and dehydrogenase activities (DHA) under different nutrition doses. The optimal inorganic nutrient dose only gave an increase of conductivity of ca. 10 μs/cm2 in the effluent on treating synthetic condensate containing methanol of 30 mg/L. The results demonstrated that biological removal of methanol was effective for the purpose of recovering the methanol-bearing condensate.

  18. Biological Phosphorus Removal in a Moving Bed Biofilm Reactor


    Helness, Herman


    Phosphorus (P) and nitrogen (N) removal from municipal wastewater is performed to prevent or reduce eutrophication in the receiving water.Both P and N can be removed physical/chemically as well as biologically. While biological processes have always dominated in N-removal, chemical P-removal is used in many cases. Biological P-removal using enhanced biological phosphorus removal (EBPR) is normally carried out in suspended culture (activated sludge) processes while biological N-removal (throug...

  19. Corn Stover Nutrient Removal Estimates for Central Iowa, USA

    Directory of Open Access Journals (Sweden)

    Douglas L. Karlen


    Full Text Available One of the most frequent producer-asked questions to those persons striving to secure sustainable corn (Zea mays L. stover feedstock supplies for Iowa’s new bioenergy conversion or other bio-product facilities is “what quantity of nutrients will be removed if I harvest my stover?” Our objective is to summarize six years of field research from central Iowa, U.S.A. where more than 600, 1.5 m2 samples were collected by hand and divided into four plant fractions: vegetative material from the ear shank upward (top, vegetative material from approximately 10 cm above the soil surface to just below the ear (bottom, cobs, and grain. Another 400 stover samples, representing the vegetative material collected directly from a single-pass combine harvesting system or from stover bales were also collected and analyzed. All samples were dried, ground, and analyzed to determine C, N, P, K, Ca, Mg, S, Al, B, Cu, Fe, Mn, and Zn concentrations. Mean concentration and dry matter estimates for each sample were used to calculate nutrient removal and estimate fertilizer replacement costs which averaged $25.06, $20.04, $16.62, $19.40, and $27.41 Mg−1 for top, bottom, cob, stover, and grain fractions, respectively. We then used the plant fraction estimates to compare various stover harvest scenarios and provide an answer to the producer question posed above.

  20. Habitat-specific nutrient removal and release in Oregon salt marshes (United States)

    Wetlands can be sources, sinks and transformers of nutrients, although it is their role in nutrient removal that is valued as a water purification ecosystem service. In order to quantify that service for any wetland, it is important to understand the drivers of nutrient removal w...

  1. Effect of nickel on nutrient removal by selected indigenous protozoan species in wastewater systems. (United States)

    Kamika, Ilunga; Momba, Maggy N B


    Nutrient and heavy metal pollutions are major concern worldwide. This study aimed at comparing the effect of Ni(2+) on nutrient removal efficiency of four indigenous wastewater protozoan species (Aspidisca sp., Paramecium sp., Peranema sp., Trachelophyllum sp.). Specific physicochemical parameters and microbial growth/die-off were measured using standard methods. The results revealed that protozoan species were able to simultaneously remove phosphate, nitrate and Ni(2+) at concentrations ranging between 66.4-99.36%, 56.19-99.88% and 45.98-85.69%, respectively. Peranema sp. appeared to be the isolates with the highest removal of nutrients (Phosphate-99.36% and Nitrate-99.88%) while Paramecium sp. showed higher removal of Ni(2+) at 85.69% and low removal of nutrients. Aspidisca sp. was the most sensitive isolate to Ni(2+) but with significant nutrient removal (Phosphate-66.4% and Nitrate-56.19%) at 10 mg-N(2+)/L followed by an inhibition of nutrient removal at Ni(2+) concentration greater than 10 mg/L. Significant correlation between the growth rate and nutrient removal (r = 0.806/0.799, p nutrient removal ability at 10 mg-Ni(2+)/L, an increase in Ni(2+) concentration had a significant effect on nutrient removal efficiency of these indigenous protozoan species. This study suggests that although Ni(2+) appeared to be toxic to microbial isolates, its effect at a low concentration (10 mg-Ni(2+)/L) towards these isolates can be used to enhance the wastewater treatment process for the removal of nutrients. Peranema sp., which was able to remove both Ni(2+) and nutrients from wastewater mixed-liquor, can also be used for bioremediation of wastewater systems.

  2. The micro and macro of nutrients across biological scales. (United States)

    Warne, Robin W


    During the past decade, we have gained new insights into the profound effects that essential micronutrients and macronutrients have on biological processes ranging from cellular function, to whole-organism performance, to dynamics in ecological communities, as well as to the structure and function of ecosystems. For example, disparities between intake and organismal requirements for specific nutrients are known to strongly affect animal physiological performance and impose trade-offs in the allocations of resources. However, recent findings have demonstrated that life-history allocation trade-offs and even microevolutionary dynamics may often be a result of molecular-level constraints on nutrient and metabolic processing, in which limiting reactants are routed among competing biochemical pathways. In addition, recent work has shown that complex ecological interactions between organismal physiological states such as exposure to environmental stressors and infectious pathogens can alter organismal requirements for, and, processing of, nutrients, and even alter subsequent nutrient cycling in ecosystems. Furthermore, new research is showing that such interactions, coupled with evolutionary and biogeographical constraints on the biosynthesis and availability of essential nutrients and micronutrients play an important, but still under-studied role in the structuring and functioning of ecosystems. The purpose of this introduction to the symposium "The Micro and Macro of Nutrient Effects in Animal Physiology and Ecology" is to briefly review and highlight recent research that has dramatically advanced our understanding of how nutrients in their varied forms profoundly affect and shape ecological and evolutionary processes.

  3. Enhancement of nutrient removal from swine wastewater digestate coupled to biogas purification by microalgae Scenedesmus spp. (United States)

    Prandini, Jean Michel; da Silva, Márcio Luís Busi; Mezzari, Melissa Paola; Pirolli, Mateus; Michelon, William; Soares, Hugo Moreira


    This work investigated the effects of swine wastewater-derived biogas on microalgae biomass production and nutrient removal rates from piggery wastewater concomitantly with biogas filtration. Photobioreactors with dominant Scenedesmus spp. were prepared using non-sterile digestate and exposed to different photoperiods. In the presence of biogas and autotrophic conditions microalgae yield of 1.1±0.2 g L(-1) (growth rate of 141.8±3.5 mg L(-1) d(-1)) was obtained leading to faster N-NH3 and P-PO4(3-) assimilation rate of 21.2±1.2 and 3.5±2.5 mg L(-1) d(-1), respectively. H2S up to 3000 ppmv was not inhibitory and completely removed. Maximum CO2 assimilation of 219±4.8 mg L(-1) d(-1) was achieved. Biological consumption of CH4 up to 18% v/v was verified. O2 up to 22% v/v was controlled by adding acetate to exacerbate oxygen demand by microorganisms. Microalgae-based wastewater treatment coupled to biogas purification accelerates nutrient removal concomitantly producing valuable biomass and biomethane.

  4. The effect of spatial pattern on nutrient removal of a wetland landscape

    NARCIS (Netherlands)

    Li, X.; Jongman, R.; Xiao, D.; Harms, W.B.; Bregt, A.K.


    The effect of spatial pattern on nutrient removal is investigated using a spatial simulation model. Field data have been used from reed marshes in the Liaohe Delta, China. Four scenarios have been designed to test the effect of different landscape components on nutrient removal in the reed marsh: ca


    Directory of Open Access Journals (Sweden)

    Juliana Sobreira de Souza


    Full Text Available management of ministumps to produce minicuttings results in the continuous removal of nutrients andit is necessary replacement to avoid depletion and decline in production. Thus, it is necessary to determinethe amount of nutrients removed over time, in different management models, to enable commercial mulproduction.The objective of this study was to evaluate two minigarden multiclonal systems of Toonaciliata, in plastic tubes and bed, for productivity and nutrients removal over time by ministumps, producedby seeds, submitted to successive collections of minicuttings. One hundred and eighty-six seedlings wereused in each management system. In this paper, it was determined the nutrient content in shoots issued by20 ministumps randomly selected in each system. Five shoots were collected at intervals of 32 days in bedsystem, while in the plastic tubes system three shoots were collected at intervals of 31 days. The data wereanalyzed by a sample simple random considering an infinite population of minicuttings. The qualitativetreatment average was compared by confidence interval using the Student t test, 5% probability, and thequantitative treatment (productivity and nutrients removed in time by ministumps by regression. It hasbeen found that the productivity and nutrient contents removed by ministumps in bed were higher than inthe plastic tubes. Nitrogen and potassium are the nutrients most removed by ministumps in both systems.Here, it was presented the curves corresponding to the nutrients exported, to estimate the replacement thatwill be made in each system over time.

  6. Wetland nutrient removal: a review of the evidence

    Directory of Open Access Journals (Sweden)

    J. Fisher


    Full Text Available Data from 57 wetlands from around the world have been collated to investigate whether wetlands affect the nutrient loading of waters draining through them; the majority of wetlands reduced nutrient loading and there was little difference in the proportion of wetlands that reduced N to those that reduced P loading. However, some wetlands increase nutrient loadings by increasing the loading of soluble N and P species thus potentially driving aquatic eutrophication. Studies conducted over a period of a year or more, or that involved frequent sampling during high flow events, were more likely to indicate that the wetland increased nutrient loadings. Swamps and marshes differed from riparian zones in their nutrient function characteristics by being slightly more effective at nutrient reduction than riparian zones. The attributes that enable wetlands to be effective in reducing N and P loadings need consideration when constructing or managing wetlands to reduce nutrient loadings. Their wise use will be an important strategy for meeting the Water Framework Directive requirements for many water bodies. Keywords: wetlands, nutrient functioning, nitrogen, phosphorus, riparian, swamps, marshes, eutrophication

  7. Identification of wastewater treatment processes for nutrient removal on a full-scale WWTP by statistical methods

    DEFF Research Database (Denmark)

    Carstensen, Jakob; Madsen, Henrik; Poulsen, Niels Kjølstad;


    with variable influent flows and pollution loads. In this paper nonlinear time series models describing the variations of the ammonia and nitrate concentrations in the aeration tanks of a biological nutrient removal WWTP are established. The models proposed herein are identified by combining well-known theory......The introduction of on-line sensors of nutrient salt concentrations on wastewater treatment plants opens a wide new area of modelling wastewater processes. Time series models of these processes are very useful for gaining insight in real time operation of wastewater treatment systems which deal...

  8. Biological anoxic phosphorus removal in a continuous-flow external nitrification activated sludge system

    Energy Technology Data Exchange (ETDEWEB)

    Kapagiannidis, A. G.; Aivasidis, A.


    Application of Biological Nutrient Removal (BNR) process in wastewater treatment is necessitated for the protection of water bodies from eutrophication. an alternative BNR method is tested for simultaneous Carbon (C), Nitrogen (N) and Phosphorus (P) removal in a continuous-flow bench scale plant for municipal wastewater treatment. The plant operation is based on the activity of two microbial populations which grow under different operational conditions (two sludge system). (Author)

  9. Using wastewater and high-rate algal ponds for nutrient removal and the production of bioenergy and biofuels. (United States)

    Batten, David; Beer, Tom; Freischmidt, George; Grant, Tim; Liffman, Kurt; Paterson, David; Priestley, Tony; Rye, Lucas; Threlfall, Greg


    This paper projects a positive outcome for large-scale algal biofuel and energy production when wastewater treatment is the primary goal. Such a view arises partly from a recent change in emphasis in wastewater treatment technology, from simply oxidising the organic matter in the waste (i.e. removing the biological oxygen demand) to removing the nutrients - specifically nitrogen and phosphorus - which are the root cause of eutrophication of inland waterways and coastal zones. A growing need for nutrient removal greatly improves the prospects for using new algal ponds in wastewater treatment, since microalgae are particularly efficient in capturing and removing such nutrients. Using a spreadsheet model, four scenarios combining algae biomass production with the making of biodiesel, biogas and other products were assessed for two of Australia's largest wastewater treatment plants. The results showed that super critical water reactors and anaerobic digesters could be attractive pathway options, the latter providing significant savings in greenhouse gas emissions. Combining anaerobic digestion with oil extraction and the internal economies derived from cheap land and recycling of water and nutrients on-site could allow algal oil to be produced for less than US$1 per litre.

  10. Nutrient Recovery of Plant Leachates Under Thermal, Biological, and Photocatalytic Pretreatments (United States)

    Wong, Les


    Nutrient recovery has always been a problem for long distance and long-term space missions. To allow humans to man these missions, a steady source of oxygen, water, and food are necessary for survival beyond Earth's atmosphere. Plants are currently an area of interest since they are capable of providing all three resources for life sustainability. We are currently interested in nutrient recovery for future plant growth and simple aqueous leachate extractions can recover some of the nutrients. However, leaching plants also removes water-soluble organic plant wastes, which inhibits plant growth if not separated properly. To combat the issues with waste and maximize nutrient recovery, we are attempting to pre-treat the plant matter using biological, thermal, and photocatalytic methods before subjecting the solution with variable-strength acid digestion. For the biological method, the inoculums: mixed heterotrophic/nitrifying bioreactor effluent and Trichoderma vessei are used in an attempt to liberate more nutrients from the plant matter. For the thermal method, plants are subjected to varying temperatures at different retention times to determine nutrient recovery. Lastly, the photocatalytic method utilizes TiO (sub 2)'s oxidizing abilities under specific pHs and retention times to reduce organic wastes and improve nutrient gains. A final acid digestion serves to liberate nutrients even further in order to maximize recovery. So far, we have tested ideal acid digestion variables for practicality and performance in our experiments. We found that a low retention time of 10 minutes and a high acid concentration of 0.1 and 1 mole HCl were the most effective at nutrient recovery. For space travel purposes, 0.1 mole currently looks like a viable acid digestion to use since it is relatively effective and sustainable from a mass and energy balance if acid recovery can be performed on waste brines. Biological pretreatments do not look to be too effective and the thermal and

  11. Hydrologic and biologic influences on stream network nutrient concentrations: Interactions of hydrologic turnover and concentration-dependent nutrient uptake (United States)

    Mallard, John; McGlynn, Brian; Covino, Tim


    Stream networks lie in a crucial landscape position between terrestrial ecosystems and downstream water bodies. As such, whether inferring terrestrial watershed processes from watershed outlet nutrient signals or predicting the effect of observed terrestrial processes on stream nutrient signals, it is requisite to understand how stream networks can modulate terrestrial nutrient inputs. To date integrated understanding and modeling of physical and biological influences on nutrient concentrations at the stream network scale have been limited. However, watershed scale groundwater - surface water exchange (hydrologic turnover), concentration-variable biological uptake, and the interaction between the two can strongly modify stream water nutrient concentrations. Stream water and associated nutrients are lost to and replaced from groundwater with distinct nutrient concentrations while in-stream nutrients can also be retained by biological processes at rates that vary with concentration. We developed an empirically based network scale model to simulate the interaction between hydrologic turnover and concentration-dependent nutrient uptake across stream networks. Exchange and uptake parameters were measured using conservative and nutrient tracer addition experiments in the Bull Trout Watershed, central Idaho. We found that the interaction of hydrologic turnover and concentration-dependent uptake combined to modify and subsequently stabilize in-stream concentrations, with specific concentrations dependent on the magnitude of hydrologic turnover, groundwater concentrations, and the shape of nutrient uptake kinetic curves. We additionally found that by varying these physical and biological parameters within measured ranges we were able to generate a spectrum of stream network concentration distributions representing a continuum of shifting magnitudes of physical and biological influences on in-stream concentrations. These findings elucidate the important and variable role of

  12. Enhanced Biological Phosphorus Removal: Metabolic Insights and Salinity Effects

    NARCIS (Netherlands)

    Welles, L.


    Enhanced biological phosphorus removal (EBPR) is a biological process for efficient phosphate removal from wastewaters through intracellular storage of polyphosphate by polyphosphate-accumulating organisms (PAO) and subsequent removal of PAO from the system through wastage of sludge. In comparison t

  13. Photomicrobial fuel cell (PFC) for simultaneous organic carbon, nutrients removal and energy production

    DEFF Research Database (Denmark)

    Zhang, Yifeng; Safa, Jafar; Angelidaki, Irini


    A sediment-type photomicrobial fuel cell (PFC), based on the synergistic interaction between microalgae (Chlorella vulgaris) and electrochemically active bacteria, was developed to remove carbon and nutrients from wastewater, and produce electricity and algal biomass simultaneously. Under...

  14. Kinetic start-up performance of two large treatment plants for nutrient removal

    DEFF Research Database (Denmark)

    Haarbo, A.; Harremoës, Poul; Thirsing, C.


    In 1987 an action plan was passed in the Danish Parliament demanding a considerable reduction of the discharge of nutrients to the aquatic environment in Denmark. Consequently, the two largest wastewater treatment plants in the Copenhagen area had to be upgraded to include nutrient removal...

  15. Nutrient removal and microalgal biomass production on urine in a short light-path photobioreactor

    NARCIS (Netherlands)

    Tuantet, K.; Temmink, B.G.; Zeeman, G.; Janssen, M.G.J.; Wijffels, R.H.; Buisman, C.J.N.


    Due to the high nitrogen and phosphorus content, source-separated urine can serve as a major nutrient source for microalgae production. The aim of this study was to evaluate the nutrient removal rate and the biomass production rate of Chlorella sorokiniana being grown continuously in urine employing

  16. Using floating vegetation to remove nutrients from an anaerobic swine wastewater lagoon (United States)

    Methods are needed for utilizing nutrients contained within animal wastewater lagoons. One potential method for removing nutrients is to have vegetation growing in the lagoon. A study was conducted from 2005-2007 to determine the feasibility of growing vegetation on floating platforms on a single ...

  17. Effect of nickel on nutrient removal by selected indigenous protozoan species in wastewater systems



    Nutrient and heavy metal pollutions are major concern worldwide. This study aimed at comparing the effect of Ni2+ on nutrient removal efficiency of four indigenous wastewater protozoan species (Aspidisca sp., Paramecium sp., Peranema sp., Trachelophyllum sp.). Specific physicochemical parameters and microbial growth/die-off were measured using standard methods. The results revealed that protozoan species were able to simultaneously remove phosphate, nitrate and Ni2+ at concentrations ranging ...

  18. Exploring Bioelectrochemical Systems for Removal and Recovery of Hexavalent Chromium or Nutrients



    Bioelectrochemical systems (BES) is a platform technology that is able to realize versatile engineering functions and recover valuable resources in an energy-efficient manner. One of the potential applications of BES is to remove and recover nutrients simultaneously from nutrient-rich wastewater, such as digested manure from livestock. A four-chamber BES was developed and used in this study to explore the potential to remove and recover hexavalent Chromium from synthetic wastewater, and ammon...

  19. Solids and nutrient removal from flushed swine manure using polyacrylamide

    Energy Technology Data Exchange (ETDEWEB)

    Perez Sangrador, M. P.; Garcia Gonzalez, M. C.; Leon Cofreces, M. C.; Acitores Benavente, M.


    Most of the organic nutrient elements (nitrogen and phosphorus) and carbon compounds (COD) in liquid swine manure are contained in fine suspended particles. Flocculation treatment with polyacrylamide (PAM) followed by screening if on the best methods to separate the liquid fraction.

  20. Ecophysiology of novel core phylotypes in activated sludge wastewater treatment plants with nutrient removal

    DEFF Research Database (Denmark)

    McIlroy, Simon Jon; Awata, Takanori; Nierychlo, Marta

    An in depth understanding of the ecology of activated sludge nutrient removal wastewater treatment systems requires detailed knowledge of the community composition and metabolic activities of individual members. Recent 16S rRNA gene amplicon surveys of activated sludge wastewater treatment plants...... with nutrient removal in Denmark indicate a core set of bacterial genera. These core genera are suggested to be responsible for the bulk of nutrient transformations underpinning the functions of these plants. While we know the basic in situ activities of some of these genera, there is little to no information...

  1. Characterization of the in situ ecophysiology of novel phylotypes in nutrient removal activated sludge treatment plants

    DEFF Research Database (Denmark)

    McIlroy, Simon Jon; Awata, Takanori; Nierychlo, Marta


    An in depth understanding of the ecology of activated sludge nutrient removal wastewater treatment systems requires detailed knowledge of the community composition and metabolic activities of individual members. Recent 16S rRNA gene amplicon surveys of activated sludge wastewater treatment plants...... with nutrient removal indicate the presence of a core set of bacterial genera. These organisms are likely responsible for the bulk of nutrient transformations underpinning the functions of these plants. While the basic activities of some of these genera in situ are known, there is little to no information...

  2. Nutrients, Recycling, and Biological Populations in Upwelling Ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Whitledge, T. E.


    Nutrient recycling has been studied in the upwelling areas of Baja California, Northwest Africa, and Peru. Regeneration by biological populations in these areas contributes significant quantities of recycled nitrogen which is utilized in productivity processes. Each area has a different combination of organisms which leads to differences in the relative contributions of zooplankton, nekton, or benthos to the nutrient cycles. Comparisons of ammonium regeneration rates of zooplankton and nekton-micronekton populations in the three upwelling areas show that zooplankton recycle relatively less nitrogen in the Baja California and Peru systems than nekton. In the Northwest Africa upwelling region, however, zooplankton, fish, and benthic inputs are all substantial. In recent years the Peruvian upwelling system has been altered with the decline of the anchoveta population and an increase in the importance of zooplankton in nutrient recycling. The distribution of recycled nitrogen (ammonium and urea) in transects across the shelf at 10°S and 15°S indicates that regeneration is relatively more important at 10°S in the region of the wide shelf. In both areas the distribution of ammonium and urea are not entirely coincident thereby indicating differences in their production and/or utilization.

  3. Removal of nutrients in various types of constructed wetlands. (United States)

    Vymazal, Jan


    The processes that affect removal and retention of nitrogen during wastewater treatment in constructed wetlands (CWs) are manifold and include NH(3) volatilization, nitrification, denitrification, nitrogen fixation, plant and microbial uptake, mineralization (ammonification), nitrate reduction to ammonium (nitrate-ammonification), anaerobic ammonia oxidation (ANAMMOX), fragmentation, sorption, desorption, burial, and leaching. However, only few processes ultimately remove total nitrogen from the wastewater while most processes just convert nitrogen to its various forms. Removal of total nitrogen in studied types of constructed wetlands varied between 40 and 55% with removed load ranging between 250 and 630 g N m(-2) yr(-1) depending on CWs type and inflow loading. However, the processes responsible for the removal differ in magnitude among systems. Single-stage constructed wetlands cannot achieve high removal of total nitrogen due to their inability to provide both aerobic and anaerobic conditions at the same time. Vertical flow constructed wetlands remove successfully ammonia-N but very limited denitrification takes place in these systems. On the other hand, horizontal-flow constructed wetlands provide good conditions for denitrification but the ability of these system to nitrify ammonia is very limited. Therefore, various types of constructed wetlands may be combined with each other in order to exploit the specific advantages of the individual systems. The soil phosphorus cycle is fundamentally different from the N cycle. There are no valency changes during biotic assimilation of inorganic P or during decomposition of organic P by microorganisms. Phosphorus transformations during wastewater treatment in CWs include adsorption, desorption, precipitation, dissolution, plant and microbial uptake, fragmentation, leaching, mineralization, sedimentation (peat accretion) and burial. The major phosphorus removal processes are sorption, precipitation, plant uptake (with

  4. Investigating the efficiency and kinetic coefficients of nutrient removal in the subsurface artificial wetland of Yazd wastewater treatment plant

    Directory of Open Access Journals (Sweden)

    Mahdi Farzadkia


    Full Text Available Background: Investigating the performance of naturally operated treatment plants may be due to the fact that they cannot be operated as desired, or that they should be modified to achieve good performance e.g. for nutrients removal. The advantage of kinetic coefficient determination is that the model can be adjusted to fit data and then used for analyzing alternatives to improve the process. This study investigates the efficiency of subsurface artificial wetland and determines its kinetic coefficients for nutrient removal. Methods: The present study investigated the kinetics of biological reactions that occurred in subsurface wetland to remove wastewater nutrient. Samples were taken from 3 locations of wetlands for 6 months. The nutrient content was determined through measuring Total Kjehldahl Nitrogen (TKN, ammonium, nitrate, and phosphate values. Results: Average levels for TKN, ammonium, nitrate, and phosphate in effluent of control wetland were 41.15, 23.59, 1.735, and 6.43 mg/L, and in wetland with reeds were 28.91, 19.99, 1.49 and 5.63 mg/L, respectively. First-order, second-order, and Stover-Kincannon models were applied and analyzed using statistical parameters obtained from the models (Umax, KB. Conclusion: The nutrients removal at Yazd wastewater treatment plant was remarkable, and the presence of reeds in wetland beds was not very efficient in improving system performance. Other more efficient plants are suggested to be evaluated in the system. Stover-Kincannon kinetic model provided predictions having the closest relationship with actual data obtained from the field.

  5. Evaluation of leaf removal as a means to reduce nutrient concentrations and loads in urban stormwater. (United States)

    Selbig, William R


    While the sources of nutrients to urban stormwater are many, the primary contributor is often organic detritus, especially in areas with dense overhead tree canopy. One way to remove organic detritus before it becomes entrained in runoff is to implement a city-wide leaf collection and street cleaning program. Improving our knowledge of the potential reduction of nutrients to stormwater through removal of leaves and other organic detritus on streets could help tailor more targeted municipal leaf collection programs. This study characterized an upper ideal limit in reductions of total and dissolved forms of phosphorus and nitrogen in stormwater through implementation of a municipal leaf collection and street cleaning program in Madison, WI, USA. Additional measures were taken to remove leaf litter from street surfaces prior to precipitation events. Loads of total and dissolved phosphorus were reduced by 84 and 83% (premoval program. Without leaf removal, 56% of the annual total phosphorus yield (winter excluded) was due to leaf litter in the fall compared to 16% with leaf removal. Despite significant reductions in load, total nitrogen showed only minor changes in fall yields without and with leaf removal at 19 and 16%, respectively. The majority of nutrient concentrations were in the dissolved fraction making source control through leaf removal one of the few treatment options available to environmental managers when reducing the amount of dissolved nutrients in stormwater runoff. Subsequently, the efficiency, frequency, and timing of leaf removal and street cleaning are the primary factors to consider when developing a leaf management program.

  6. A new method for nutrients removal and recovery from wastewater using a bioelectrochemical system. (United States)

    Zhang, Fei; Li, Jian; He, Zhen


    Nutrients management is a key task of wastewater treatment and removal of nutrients is usually associated with significant energy/economic cost. A new bioelectrochemical system, named "R(2)-BES", was developed for removing and possibly recovering nutrients from wastewater. This R(2)-BES takes advantage of bioelectricity generation from oxidation of organic compounds to drive ammonium migration out of wastewater, and uses hydroxide ions produced from the cathode reaction as a medium to exchange phosphate ions from wastewater at the same time. Under an applied voltage of 0.8 V, the R(2)-BES removed 83.4 ± 1.3% of ammonium nitrogen and 52.4 ± 9.8% of phosphate, significantly higher than those (3.6 ± 3.7% and 21.1 ± 2.6%) under an open circuit condition. Applying an external voltage can increase current generation, COD removal, and nutrient removal. Those results demonstrate a proof of concept that the R(2)-BES may be potentially applied to remove and recover nutrients through appropriate integration into the existing treatment facilities.

  7. Comparison of Habitat-Specific Nutrient Removal and Release in Pacific NW Salt Marshes at Multiple Spatial Scales (United States)

    Wetlands can be sources, sinks and transformers of nutrients, although it is their role in nutrient removal that is valued as a water purification ecosystem service. In order to quantify that service for any wetland, it is important to understand the drivers of nutrient removal w...

  8. Comparison of Habitat-Specific Nutrient Removal and Release in Pacific NW Salt Marshes at Multiple Spatial Scales - CERF (United States)

    Wetlands can be sources, sinks and transformers of nutrients, although it is their role in nutrient removal that is valued as a water purification ecosystem service. In order to quantify that service for any wetland, it is important to understand the drivers of nutrient removal w...

  9. Biological phosphorus removal inhibition by roxarsone in batch culture systems. (United States)

    Guo, Qingfeng; Liu, Li; Hu, Zhenhu; Chen, Guowei


    Roxarsone has been extensively used in the feed of animals, which is usually excreted unchanged in the manure and eventually enter into animal wastewater, challenging the biological phosphorus removal processes. Knowledge of its inhibition effect is key for guiding treatment of roxarsone-contaminated wastewater, and is unfortunately keeping unclear. We study the inhibition of roxarsone on biological phosphorus removal processes for roxarsone-contaminated wastewater treatment, in terms of the removal and rates of chemical oxygen demand (COD), phosphate. Results showed that presence of roxarsone considerably limited the COD removals, especially at roxarsone concentration exceeding 40 mg L(-1). Additionally, roxarsone inhibited both phosphorus release and uptake processes, consistent with the phosphate profiles during the biological phosphorus removal processes; whereas, roxarsone is more toxic to phosphorus uptake process, than release function. The results indicated that it is roxarsone itself, rather than the inorganic arsenics, inhibit biological phosphorus removal processes within both aerobic and anaerobic roxarsone-contaminated wastewater treatment.

  10. Nutrients removal using moving beds with aeration cycles

    Energy Technology Data Exchange (ETDEWEB)

    Martin Martin, A.; Foresti, E.; Garcia-Encina, P. A.


    Moving Bed Biofilm Reactors (MBBR) are based on the biomass growth over a media that moves into the reactor due to aeration, mechanical agitation or recirculation. These reactors have been gaining popularity and they are employed in hundreds of plants everywhere with different treatment purposes (organic matter removal, nitrification/denitrification), both for urban and industrial wastewater. (Author)

  11. Biological - Elwha River Dam Removal Study (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This study examines the ecosystem response of the Elwha River to the removal of the Elwha River dams. We will measure the following attributes of ecosystem response:...

  12. Nutrient and biological conditions of selected small streams in the Edwards Plateau, central Texas, 2005-06, and implications for development of nutrient criteria (United States)

    Mabe, Jeffrey A.


    During the summers of 2005 and 2006 the U.S. Geological Survey, in cooperation with the Texas Commission on Environmental Quality, evaluated nutrient and biological conditions in small streams in parts of the Edwards Plateau of Central Texas. Land-cover analysis was used to select 15 small streams that represented a gradient of conditions with the potential to affect nutrient concentrations across the study area, which comprises two of four subregions of the Edwards Plateau ecoregion. All 15 streams were sampled for water properties, nutrients, algae, benthic invertebrates, and fish in summer 2005, and eight streams were resampled in summer 2006. Streams that did not receive wastewater effluent had relatively low nutrient concentrations and were classified as oligotrophic; streams receiving wastewater effluent had relatively high nutrient concentrations and were classified as eutrophic. Nutrient concentrations measured in the least-disturbed streams closely matched the U.S. Environmental Protection Agency nutrient criteria recommendations based on estimated reference concentrations. Nitrogen/phosphorus ratios indicated streams not affected by wastewater effluent might be limited by phosphorus concentrations. Algal indicators of nutrient condition were closely related to dissolved nitrogen concentrations and streamflow conditions. Ambient dissolved nitrogen concentrations (nitrite plus nitrate) were positively correlated with benthic algal chlorophyll-a concentrations. The correlation of benthic algal chlorophyll-a with instantaneous nitrite plus nitrate load was stronger than correlations with ambient nutrients. Increased nutrient concentrations were associated with increased macroalgae cover, wider diel dissolved oxygen ranges, and reduced diel dissolved oxygen minimums. Benthic invertebrate aquatic life use scores generally were classified as High to Exceptional in study streams despite the influence of urbanization or wastewater effluent. Reductions in aquatic

  13. Data to support "Boosted Regression Tree Models to Explain Watershed Nutrient Concentrations & Biological Condition" (United States)

    U.S. Environmental Protection Agency — Spreadsheets are included here to support the manuscript "Boosted Regression Tree Models to Explain Watershed Nutrient Concentrations and Biological Condition". This...

  14. Comparison of Nutrients and Salinity on Phenanthrene Removal from Polluted Soil 

    Directory of Open Access Journals (Sweden)

    Maasoumeh Ravanipour


    Full Text Available Background and Objectives:The poor accessibility of microorganisms to PAHs in soil has limited success in the process of bioremediation as an effective method for removing pollutants from soils. Different physicochemical factors are effective on the rate of biodegradation. The main objective of this study is to assess effects of nutrient and salinity on phenanthrene removal from polluted soils.Materials and Methods:The soil having no organic and microbial pollution was first artificially polluted with phenanthrene then nutrients and salinity solution in two concentrations were added to it in order to have the proportion of 10% w:v (soil: water. After that a microbial mixture enable to degrade phenanthrene was added to the slurry and was aerated. Finally, the residual concentration of Phenanthrene in the soil was extracted by ultrasonic and was analyzed using GC. We measured the microbial populationusing MPN test. This study was conducted based on the two level full factorial design of experiment. Results: MPN test showed that the trend of microbial growth has experienced a lag growth. The full factorial design indicated that nutrient had the maximum effect on bioremediation; the rate of phenanthrene removal in the maximum nutrients - minimum salinity solution was 75.14%.Conclusion: This study revealed that the more nutrient concentration increases, the more degradation will be happened by microorganisms in the soils. However, salinity in the concentration used had no effect on inhabitation or promoting on the Phenanthrene removal.

  15. The rapid return of marine-derived nutrients to a freshwater food web following dam removal (United States)

    Tonra, Christopher M; Sager-Fradkin, Kimberly A.; Morley, Sarah A; Duda, Jeff; Marra, Peter P.


    Dam removal is increasingly being recognized as a viable river restoration action. Although the main beneficiaries of restored connectivity are often migratory fish populations, little is known regarding recovery of other parts of the freshwater food web, particularly terrestrial components. We measured stable isotopes in key components to the freshwater food web: salmon, freshwater macroinvertebrates and a river specialist bird, American dipper (Cinclus mexicanus), before and after removal of the Elwha Dam, WA, USA. Less than a year after dam removal, salmon returned to the system and released marine-derived nutrients (MDN). In that same year we documented an increase in stable-nitrogen and carbon isotope ratios in American dippers. These results indicate that MDN from anadromous fish, an important nutrient subsidy that crosses the aquatic–terrestrial boundary, can return rapidly to food webs after dams are removed which is an important component of ecosystem recovery.

  16. Nutrient removal and biogas upgrading by integrating freshwater algae cultivation with piggery anaerobic digestate liquid treatment. (United States)

    Xu, Jie; Zhao, Yongjun; Zhao, Guohua; Zhang, Hui


    An integrated approach that combined freshwater microalgae Scenedesmus obliquus (FACHB-31) cultivation with piggery anaerobic digestate liquid treatment was investigated in this study. The characteristics of algal growth, biogas production, and nutrient removal were examined using photobioreactor bags (PBRbs) to cultivate S. obliquus (FACHB-31) in digestate with various digestate dilutions (the concentration levels of 3200, 2200, 1600, 1200, 800, and 400 mg L(-1) chemical oxygen demand (COD)) during 7-day period. The effects of the level of pollutants on nutrient removal efficiency and CO2 removal process were investigated to select the optimum system for effectively upgrade biogas and simultaneously reduce the nutrient content in digestate. The treatment performance displayed that average removal rates of COD, total nitrogen (TN), total phosphorous (TP), and CO2 were 61.58-75.29, 58.39-74.63, 70.09-88.79, and 54.26-73.81 %, respectively. All the strains grew well under any the dilution treatments. With increased initial nutrient concentration to a certain range, the CO4 content (v/v) of raw biogas increased. Differences in the biogas enrichment of S. obliquus (FACHB-31) in all treatments mainly resulted from variations in biomass productivity and CO2 uptake. Notably, the diluted digestate sample of 1600 mg L(-1) COD provided an optimal nutrient concentration for S. obliquus (FACHB-31) cultivation, where the advantageous nutrient and CO2 removals, as well as the highest productivities of biomass and biogas upgrading, were revealed. Results showed that microalgal biomass production offered real opportunities to address issues such as CO2 sequestration, wastewater treatment, and biogas production.

  17. Comparison of Nutrients and Salinity on Phenanthrene Removal from Polluted Soil 



    Background and Objectives:The poor accessibility of microorganisms to PAHs in soil has limited success in the process of bioremediation as an effective method for removing pollutants from soils. Different physicochemical factors are effective on the rate of biodegradation. The main objective of this study is to assess effects of nutrient and salinity on phenanthrene removal from polluted soils.Materials and Methods:The soil having no organic and microbial pollution was first artificially poll...

  18. Impacts of multiwalled carbon nanotubes on nutrient removal from wastewater and bacterial community structure in activated sludge.

    Directory of Open Access Journals (Sweden)

    Reti Hai

    biological wastewater nutrient removal, and altered the diversity and structure of bacterial community in activated sludge.

  19. Removal of nutrients and metals by constructed and naturally created wetlands in the Las Vegas Valley, Nevada. (United States)

    Adhikari, Achyut R; Acharya, Kumud; Shanahan, Seth A; Zhou, Xiaoping


    Increased water use associated with rapid growth in the Las Vegas Valley has inadvertently led to the creation of unique wetland systems in Southern Nevada with an abundance of biological diversity. Constructed and naturally created wetlands in the Las Vegas Valley watershed were studied to characterize and understand their potential role for improving ecosystem services (i.e., water purification). Nutrient and metal removal was assessed at four sites including a natural urban runoff wetland, a constructed urban runoff wetland, a constructed wastewater wetland, and a natural urban runoff/wastewater wetland. Plant nutrient uptake was dependent on ambient nutrient concentrations in water and sediments of specific wetlands, irrespective of the type of plants present. Phosphorus was mostly concentrated in below-ground plant parts whereas nitrogen was concentrated in above-ground parts. As for metalloids, bulrushes were more efficient than cattails at taking up arsenic and selenium. Averaging all the wetland sites and plant species, total nitrogen, phosphorus, arsenic and selenium removal was 924.2, 61.5, 0.30, and 0.38 kg/ha/year, respectively. Our findings suggest that natural and created wetland systems can improve water quality in the Las Vegas Valley watershed for some common pollutants, however, other measures are still needed to improve water quality below regulatory thresholds.

  20. Comparison of four aquatic plant treatment systems for nutrient removal from eutrophied water. (United States)

    Li, Jihua; Yang, Xiaoying; Wang, Zhengfang; Shan, Ying; Zheng, Zheng


    Nutrient removal behaviors of four aquatic plant treatment systems (Oenanthe javanica, Iris pseudacorus L., Canna lily, and Potamogeton crispus) were systematically examined and compared. The kinetics of nutrient uptake were conducted with the standard depletion method. All four aquatic species exhibited a strong preference of ammonium nitrogen (NH4(+)-N) over nitrate nitrogen (NO3(-)-N) and nitrite nitrogen (NO2(-)-N). Main pathways of nutrient removal in the aquatic plant treatment system were examined in details. It was estimated that direct assimilation by plants accounted for 28.2-34.5% of N reduction and 25.2-33.4% of P reduction while substrate absorption accounted for 7.2-25.5% of N reduction and 7.3-25.0% of P reduction. The activity of urease and phosphatase in the substrates could indicate the aquatic plant treatment system's capability for reducing TN and soluble P load.

  1. External Carbon Source Addition as a Means to Control an Activated Sludge Nutrient Removal Process

    DEFF Research Database (Denmark)

    Isaacs, Steven Howard; Henze, Mogens; Søeberg, Henrik;


    In alternating type activated sludge nutrient removal processes, the denitrification rate can be limited by the availability of readily-degradable carbon substrate. A control strategy is proposed by which an easily metabolizable COD source is added directly to that point in the process at which...

  2. Comparing two surface flow wetlands for removal of nutrients in agricultural drainage water

    DEFF Research Database (Denmark)

    Hoffmann, Carl Christian; Kjærgaard, Charlotte; Levesen, Bo

    In Denmark there is a growing interest for using constructed wetlands as a mean for removal of nutrients from agricultural run-off, such as drainage ditches and tile drainage systems. We have studied two surface flow constructed wetlands from district Vejle, Jutland, Denmark. The Vicarage Wetland...

  3. Corn stover nutrient removal estimates for Central Iowa, U.S.A. (United States)

    One of the most frequently asked questions to those striving to secure sustainable corn (Zea mays L.) stover feedstock supplies for Iowa’s new bioenergy conversion facilities is “what quantity of nutrients will be removed if I harvest my stover?”. Our objective is to summarize six years of field res...

  4. Efficiency of three halophyte species in removing nutrients from saline water

    NARCIS (Netherlands)

    Lange, de H.J.; Paulissen, M.P.C.P.


    Saline wetlands may be well suited for purifying contaminated water from saline agriculture and aquaculture or from freshwater-based agriculture in areas subject to increased salinity. However, case studies on the nutrient removal efficiency of halophyte species are scarce, especially for tempera

  5. Removal of UV 254 nm matter and nutrients from a photobioreactor-wetland system. (United States)

    Wu, Yonghong; He, Jiangzhou; Hu, Zhengyi; Yang, Linzhang; Zhang, Naiming


    The output of organic pollutants and excessive nutrients in intensive agricultural areas has frequently occurred, which easily lead to pollution events such as harmful algal blooms in downstream aquatic ecosystems. A photobioreactor-wetland system was applied to remove UV(254 nm) matter and dissolved nutrients discharged from an intensive agricultural area in the Kunming region of western China. The photobioreactor-wetland system was composed of two main components: an autotrophic photobioreactor with replanted macrophytes and a constructed wetland. The results showed that there was a significant correlation between UV(245)(nm) absorbance and chemical oxygen demand (COD) concentration in the effluent of the agricultural ecosystem. When the hydraulic load of the photobioreactor-wetland system was 500 m(3)day(-1), the UV(254 nm) absorbance was dramatically reduced, and dissolved nutrients such as TDP, NO(3)-N and NH(4)-N were effectively removed. The overall average removal efficiencies were as follows in relatively steady-state conditions: UV(254 nm) matter (66%), TDP (71%), NO(3)-N (75%) and NH(4)-N (65%). Simpson's diversity index of zoobenthos indicated that the system could increase the zoobenthic diversity and improve the growth conditions of the zoobenthos habitat. The results also showed that the photobioreactor-wetland system could remove the UV(254 nm) matter and dissolved nutrients, providing a promising bio-measure for reducing the risk of pollution event occurrences in downstream surface waters.

  6. Removal of nutrients from piggery wastewater using struvite precipitation and pyrogenation technology. (United States)

    Huang, Haiming; Xu, Chunlian; Zhang, Wei


    In this paper, removal of nutrients from piggery wastewater by struvite crystallization was conducted using a combined technology of low-cost magnesium source in struvite precipitation and recycling of the struvite pyrolysate in the process. In the present research, it was found that high concentrations of K(+) and Ca(2+) present in the solution significantly affected the removal of nutrients. When the struvite crystallization formed at the condition of dosing the magnesite pyrolysate at a Mg:N:P molar ratio of 2.5:1:1, and having a reaction time of 6 h, a majority of nutrients in piggery wastewater can be removed. Surface characterization analysis demonstrated that the main components of the pyrolysate of the obtained struvite were amorphous magnesium sodium phosphate (MgNaPO(4)) and MgO. When the struvite pyrolysate was recycled in the process at the pH range of 8.0-8.5, the precipitation effect was optimum. When the struvite pyrolysate was recycled repeatedly at pH 8.5 or without any adjustment of pH, the outcome of the removal of the nutrients in both cases was similar. With the increase in the number of recycle times, the performance of struvite precipitation progressively decreased. An economic evaluation showed that the combination of using low-cost material and recycling of struvite was feasible. Recycling struvite for three process cycles could save the chemical costs by 81% compared to the use of pure chemicals.

  7. Nutrients and pharmaceuticals removal from wastewater by culture and harvesting of Chlorella sorokiniana. (United States)

    Escapa, C; Coimbra, R N; Paniagua, S; García, A I; Otero, M


    This work aimed to study both the removal of nutrients and pharmaceuticals, namely salicylic acid or paracetamol, from water by the culture of Chlorella sorokiniana. The removal of nutrients was nearly complete at the end of the batch culture; above 70% for nitrates and 89% for phosphates in the semicontinuous culture. The pharmaceuticals removal kinetics were 2.3 times greater for the salicylic acid than paracetamol, reaching volumetric efficiencies above 93% for salicylic acid in the semicontinuous culture. Finally, to separate the microalgae biomass from treated water, metal salts, synthetic polyelectrolytes and a biopolymer were tested as coagulants-flocculants. The best flocculation results were achieved with AlCl3 (95.23% with 200mgg(-1), 1min incubation time). However, given that resulting flocs had different characteristics, flocculants must be chosen on the basis of the subsequent use of the biomass.

  8. Evaluation of leaf removal as a means to reduce nutrient concentrations and loads in urban stormwater (United States)

    Selbig, William R.


    While the sources of nutrients to urban stormwater are many, the primary contributor is often organic detritus, especially in areas with dense overhead tree canopy. One way to remove organic detritus before it becomes entrained in runoff is to implement a city-wide leaf collection and street cleaning program. Improving our knowledge of the potential reduction of nutrients to stormwater through removal of leaves and other organic detritus on streets could help tailor more targeted municipal leaf collection programs. This study characterized an upper ideal limit in reductions of total and dissolved forms of phosphorus and nitrogen in stormwater through implementation of a municipal leaf collection and street cleaning program in Madison, WI, USA. Additional measures were taken to remove leaf litter from street surfaces prior to precipitation events.

  9. Identification and evaluation of a dominant alga from municipal wastewater in removal of nutrients. (United States)

    Yang, Yixuan; Tang, Fei; Su, Xiaoling; Yin, Hua; Ge, Fei


    To access better removal of nutrients with algae-based techniques, a dominant alga from real municipal wastewater was identified and its capacity in removing low concentrations of nitrogen (NH(+)4 or NO(-)3) and phosphorus (PO(3-)4) was evaluated. Results showed that Oedogonium brevicingulatum, a filamentous green alga, was confirmed as the dominant alga in the secondary effluent of a municipal wastewater treatment plant by polymerase chain reaction-denaturing gradient gel electrophoresis. Low concentrations of NH(+)4 or NO(-)3 (≤5 mg N L(-1)) and PO(3-)4 (≤0.5 mg P L(-1)) were 100% removed by the algae in a 7-d test. The maximum nutrient removal rate (Vmax) and the half-saturation constant (Km) for NH(+)4 (10.03 ± 0.95 mg g(-1)d(-1) and 0.19 ± 0.03 mg L(-1)) and NO(-)3 (8.43 ± 0.21 mg g(-1) d(-1) and 0.27 ± 0.11 mg L(-1)) indicated the uptake capability for NH(+)4 is higher than that for NO(-)3. Meanwhile, it showed higher affinity for PO(3-)4 (Vmax: 1.42 ± 0.02 mg g(-1) d(-1); Km: 0.02 ± 0.00 mg L(-1)) with NH(+)4 as nitrogen source than that (Vmax: 1.24 ± 0.15 mg g(-1) d(-1); Km: 0.06 ± 0.03 mg L(-1)) with NO(-)3 as nitrogen source. Moreover, nutrient removal efficiencies were observed steady when nitrogen/phosphorus ratio ranged from 5:1 to 20:1. These results suggest that the dominant algae from municipal wastewater have potentials to be applied in nutrient removal.

  10. Removal of arsenic and iron removal from drinking water using coagulation and biological treatment. (United States)

    Pramanik, Biplob Kumar; Pramanik, Sagor Kumar; Suja, Fatihah


    Effects of biological activated carbon (BAC), biological aerated filter (BAF), alum coagulation and Moringa oleifera coagulation were investigated to remove iron and arsenic contaminants from drinking water. At an initial dose of 5 mg/L, the removal efficiency for arsenic and iron was 63% and 58% respectively using alum, and 47% and 41% respectively using Moringa oleifera. The removal of both contaminants increased with the increase in coagulant dose and decrease in pH. Biological processes were more effective in removing these contaminants than coagulation. Compared to BAF, BAC gave greater removal of both arsenic and iron, removing 85% and 74%, respectively. Longer contact time for both processes could reduce the greater concentration of arsenic and iron contaminants. The addition of coagulation (at 5 mg/L dosage) and a biological process (with 15 or 60 min contact time) could significantly increase removal efficiency, and the maximum removal was observed for the combination of alum and BAC treatment (60 min contact time), with 100% and 98.56% for arsenic and iron respectively. The reduction efficiency of arsenic and iron reduced with the increase in the concentration of dissolved organics in the feedwater due to the adsorption competition between organic molecules and heavy metals.

  11. Nutrient and dissolved organic carbon removal from natural waters using industrial by-products. (United States)

    Wendling, Laura A; Douglas, Grant B; Coleman, Shandel; Yuan, Zheng


    Attenuation of excess nutrients in wastewater and stormwater is required to safeguard aquatic ecosystems. The use of low-cost, mineral-based industrial by-products with high Ca, Mg, Fe or Al content as a solid phase in constructed wetlands potentially offers a cost-effective wastewater treatment option in areas without centralised water treatment facilities. Our objective was to investigate use of water treatment residuals (WTRs), coal fly ash (CFA), and granular activated carbon (GAC) from biomass combustion in in-situ water treatment schemes to manage dissolved organic carbon (DOC) and nutrients. Both CaO- and CaCO(3)-based WTRs effectively attenuated inorganic N species but exhibited little capacity for organic N removal. The CaO-based WTR demonstrated effective attenuation of DOC and P in column trials, and a high capacity for P sorption in batch experiments. Granular activated carbon proved effective for DOC and dissolved organic nitrogen (DON) removal in column trials, but was ineffective for P attenuation. Only CFA demonstrated effective removal of a broad suite of inorganic and organic nutrients and DOC; however, Se concentrations in column effluents exceeded Australian and New Zealand water quality guideline values. Water treated by filtering through the CaO-based WTR exhibited nutrient ratios characteristic of potential P-limitation with no potential N- or Si-limitation respective to growth of aquatic biota, indicating that treatment of nutrient-rich water using the CaO-based WTR may result in conditions less favourable for cyanobacterial growth and more favourable for growth of diatoms. Results show that selected industrial by-products may mitigate eutrophication through targeted use in nutrient intervention schemes.

  12. Enhanced nutrient removal in three types of step feeding process from municipal wastewater. (United States)

    Peng, Yongzhen; Ge, Shijian


    An anoxic/oxic step feeding process was improved to enhance nutrient removal by reconfiguring the process into (1) anaerobic/anoxic/oxic step feeding process or (2) modified University of Capetown (UCT) step feeding process. Enhanced nitrogen and phosphorus removal and optimized organics utilization were obtained simultaneously in the modified UCT type with both internal and sludge recycle ratios of 75% as well as anaerobic/anoxic/oxic volume ratio of 1:3:6. Specifically, the UCT configuration and optimized operational conditions lead to the enrichment of denitrifying phosphorus removal microorganisms and achieved improved anaerobic P-release and anoxic P-uptake activities, which were beneficial to the denitrifying phosphorus removal activities and removal efficiencies. Due to high mixed liquor suspended solid and uneven distributed dissolved oxygen, 35% of total nitrogen was eliminated through simultaneous nitrification and denitrification process in aerobic zones. Moreover, 62 ± 6% of influent chemical oxygen demands was involved in the denitrification or phosphorus release processes.

  13. Optimization of hard clams, polychaetes, physical disturbance and denitrifying bacteria of removing nutrients in marine sediment. (United States)

    Shen, Hui; Thrush, Simon F; Wan, Xihe; Li, Hui; Qiao, Yi; Jiang, Ge; Sun, Ruijian; Wang, LiBao; He, Peimin


    Marine organisms are known to play important roles in transforming nutrients in sediments, however, guidelines to optimize sediment restoration are not available. We conducted a laboratory mesocosm experiment to investigate the role of hard clams, polychaetes, the degree of physical disturbance and denitrifying bacterial concentrations in removing total nitrogen (TN), total phosphorus (TP), and total organic carbon (TOC) in marine sediments. Response surface methodology was employed to analyze the results of initial experiments and in a subsequent experiment identified optimal combinations of parameters. Balancing the TN, TP, TOC removal efficiency, our model predicted 39% TN removal, 33% TP removal, and 42% TOC removal for a 14-day laboratory bioremediation trial using hard clams biomass of 1.2kgm(-2), physical disturbance depth of 16.4cm, bacterial density of 0.18Lm(-2), and polychaetes biomass of 0.16kgm(-2), respectively. These results emphasize the value of combining different species in field-based bioremediation.

  14. Nutrients removal and nitrous oxide emission during simultaneous nitrification, denitrification, and phosphorus removal process: effect of iron. (United States)

    Jia, Wenlin; Wang, Qian; Zhang, Jian; Yang, Weihua; Zhou, Xiaowei


    The short- and long-term influences of ferric iron (Fe(III)) on nutrients removal and nitrous oxide (N2O) emission during SNDPR process were evaluated. According to the continuous cycle experiments, it was concluded that the addition of Fe(III) could lower the nitrogen removal of the following cycle during SNDPR process, which was mainly induced by the chemical removal of phosphorus. However, the impacts were transitory, and simultaneous nitrogen and phosphorus removal would recover from the inhibition of Fe(III) after running certain cycles. Moreover, the addition of Fe(III) could stimulate N2O emission transitorily during SNDPR process. However, if Fe(III) was added into reactor continuously, the nitrogen removal would be improved, especially at low Fe load condition. It was because that the activity of NO reductase was enhanced by the addition of Fe. However, the low Fe load in reactor would induce more N2O emission. When Fe(III) load was 40 mg/L in the reactor, the N2O yield was 10 % higher than control. The TN removal was weakened when Fe(III) load reached to 60 mg/L, and the N2O yield was lower than control, due to the inhibition of the high Fe load on denitrification enzymes.

  15. Seed removal by scatter-hoarding rodents: the effects of tannin and nutrient concentration. (United States)

    Wang, Bo; Yang, Xiaolan


    The mutualistic interaction between scatter-hoarding rodents and seed plants have a long co-evolutionary history. Plants are believed to have evolved traits that influence the foraging behavior of rodents, thus increasing the probability of seed removal and caching, which benefits the establishment of seedlings. Tannin and nutrient content in seeds are considered among the most essential factors in this plant-animal interaction. However, most previous studies used different species of plant seeds, rendering it difficult to tease apart the relative effect of each single nutrient on rodent foraging behavior due to confounding combinations of nutrient contents across seed species. Hence, to further explore how tannin and different nutritional traits of seed affect scatter-hoarding rodent foraging preferences, we manipulated tannin, fat, protein and starch content levels, and also seed size levels by using an artificial seed system. Our results showed that both tannin and various nutrients significantly affected rodent foraging preferences, but were also strongly affected by seed size. In general, rodents preferred to remove seeds with less tannin. Fat addition could counteract the negative effect of tannin on seed removal by rodents, while the effect of protein addition was weaker. Starch by itself had no effect, but it interacted with tannin in a complex way. Our findings shed light on the effects of tannin and nutrient content on seed removal by scatter-hoarding rodents. We therefore, believe that these and perhaps other seed traits should interactively influence this important plant-rodent interaction. However, how selection operates on seed traits to counterbalance these competing interests/factors merits further study.

  16. Optimization of simultaneous biomass production and nutrient removal by mixotrophic Chlorella sp. using response surface methodology. (United States)

    Lee, Yu-Ru; Chen, Jen-Jeng


    The bioprospecting of potentially mixotrophic microalgae in a constructed wetland was conducted. A locally isolated microalga, Chlorella sp., was grown to determine the effect of temperature, aeration rate, and cultivation time on simultaneous biomass production and nutrient removal from piggery wastewater using central composite design (CCD). The most important variable for the biomass productivity of Chlorella sp. was aeration rate, while that for lipid content and nutrient removal efficiency was cultivation time. Total nitrogen (TN) and total phosphorus (TP) removal efficiencies were higher than that of chemical oxygen demand (COD) from piggery wastewater. The CCD results indicate that the highest biomass productivity (79.2 mg L(-1) d(-1)) and simultaneous nutrient removal efficiency (TN 80.9%, TP 99.2%, COD 74.5%) were obtained with a cultivation temperature of 25 °C, a cultivation time of 5 days, and an air aeration rate of 1.6 L L(-1) min(-1). Palmitic acid (C16:0) and linoleic acid (C18:2) were both abundant in Chlorella sp. cells under mixotrophic cultivation with piggery wastewater.

  17. Nutrient removal by grasses irrigated with wastewater and nitrogen balance for reed canarygrass

    Energy Technology Data Exchange (ETDEWEB)

    Geber, U.


    To develop complementary wastewater treatment systems that increase nutrient reduction and recycling, an experiment was conducted to evaluate the efficiency of three grass species as catch crops for N, P, and K at Aurahammar wastewater treatment plant (WWTP) in the southern part of Sweden. Another objective was also to assess soil accumulation of N, P, and K and the risk of N leaching by drainage. Three grasses--reed canarygrass (Phalaris arundinacea L.), meadow foxtail (Alopecurus pratensis L.), and smooth bromegrass (Bromus inermis Leyss.)--were irrigated with a mixture of treated effluent and supernatant at two levels of intensity [optimum level (equal to evapotranspiration) and over-optimal level] and at two nutrient levels, approximately 150 and 300 kg N ha{sup {minus}1}. There were small differences in dry matter (DM) yield between grass species and no difference in N removal among species. The amount of N removed in harvested biomass to N applied was 0.58 in 1995 and 0.63 in 1996. The amount of N removed increased with increased nutrient load. Applied amounts of P were the same as P in harvested biomass. All species removed K amounts several times greater than applied amounts. Increased nutrient load increased overall K removal. The low amount of mineral N and especially NO{sub 3}{sup {minus}}-N in the soil profile in autumn samplings indicate the risk for leaching is small. Soil water NO{sub 3}{sup {minus}} contents were also low, <2.5 mg NO{sub 3}{sup {minus}}-N L{sup {minus}1} during the growing season, with a mean value of <1 mg NO{sub 3}{sup {minus}}-N L{sup {minus}1}.

  18. [Ecological stability on biological removal of iron and manganese filter under poor nutritional conditions]. (United States)

    Yang, Hong; Xiong, Xiao-Li; Duan, Xiao-Dong; Song, Li-Xin; Yu, Ping-Bo; Li, Wei; Zhang, Jie


    To supply necessary bacteria and available nutrients, a method of returning backwashing wastewater to the bio-filter for removal of iron and manganese was used. The ecological stability of bio-filter was investigated from 3 aspects: iron and manganese removal efficiency, micro-ecological characteristics and the quantity distribution of dominant bacteria. The results indicated that, the bio-filter held strong antishock loading capability, when the system was operated at high filtration rate (10-13.9 m/h) and high manganese concentration (3.5-4.5 mg/L), a removal rate more than 98.9% of iron and manganese was achieved. Iron and manganese oxidizing bacteria are the dominant microflora in biological filtering layer, they not only adhere on filter sand materials (4.3 x 10(6) MPN/mL) to form compact biofilm, but also exist among filter materials void (6.5 x 10(6) MPN/mL) to form suspended flocs, which is very important to complete removal of iron and manganese. In the past 5 years, the bio-filter realized a continuous and stable operation and kept a high removal efficiency of iron and manganese without adding any nutrients.

  19. Estimating the carrying capacity of green mussel cultivation by using net nutrient removal model. (United States)

    Srisunont, Chayarat; Babel, Sandhya


    This study aims to evaluate the nutrient removal potential and carrying capacity of green mussel cultivation by using the mass balance model. The developed model takes into consideration the green mussel growth rate, density and chlorophyll a concentration. The data employed in this study were based on culture conditions at Sriracha Fisheries Research Station, Thailand. Results show that net nutrient removal by green mussel is 3302, 380, and 124mg/year/indv for carbon, nitrogen, and phosphorus respectively. The carrying capacity of green mussel cultivation was found to be 300indv/m(2) based on chlorophyll a concentration which will not release phosphorus in the water environment beyond the standard (45μg-PO4(-3)-P/L). Higher chlorophyll a concentration results in lowered green mussel carrying capacity. This model can assist farm operators with possible management strategies for a sustainable mussel cultivation and protection of the marine environment.

  20. A Potential Waste to be Selected as Media for Metal and Nutrient Removal (United States)

    Zayadi, N.; Othman, N.; Hamdan, R.


    This study describes the potential of application of cassava peel, banana peel, coconut shell, and coconut coir to be selected as metal removal while limestone and steel slag for nutrient removal. The media were characterized by X-Ray Fluorescence (XRF), Fourier Transform Infrared (FTIR), Field Emission Scanning Electron Microscopy-Energy Dispersive X-Ray (FESEM-EDX), and X-Ray Powder Diffraction (XRD). The results of XRF analysis medias show the present of calcium oxide, CaO which confirm the high efficiency in adsorbing metal ions and nutrient which is in agreement with the result of XRD. The characteristics of medias by FTIR analysis also confirmed the involvement of alcohol, carboxylic, alkanes, amines and ethers which play important role to reduce ions while FESEM-EDX indicates the porous structures of study medias. The characterization analysis highlight that cassava peel and steel slag were selected as a potential media in this study.

  1. Regeneration of nutrients and biological productivity in Antarctic waters

    Digital Repository Service at National Institute of Oceanography (India)

    Verlecar, X.N.; Somasundar, K.; Qasim, S.Z.

    Physique E Chirnie Marine, France, for their expert comments on the manuscript. LITERATURE CITED Allanson, B. R., Hart, R. C, Lutjerhams, J. R. E. (1981). Obser vations on the nutrients, chlorophyll and primary produc tion of Southern Oceans south...

  2. Nutrient removal through autumn harvest of Phragmites australis and Thypha latifolia shoots in relation to nutrient loading in a wetland system used for polishing sewage treatment plant effluent. (United States)

    Toet, Sylvia; Bouwman, Meike; Cevaal, Annechien; Verhoeven, Jos T A


    The efficacy and feasibility of annual harvesting of Phragmites australis and Typha latifolia shoots in autumn for nutrient removal was evaluated in a wetland system used for polishing sewage treatment plant (STP) effluent. Aboveground biomass and nutrient dynamics nutrient removal through harvest were studied in parallel ditches with stands of Phragmites or Typha that were mown in October during two successive years. The inflow rate of STP effluent to the ditches was experimentally varied, resulting in pairs of ditches with mean hydraulic retention times (HRT) of 0.3, 0.8, 2.3, and 9.3 days, corresponding to N and P mass loading rates of 122-4190 g N m(-2) yr(-1) and 28.3-994 g P m(-2) yr(-1). Nitrogen and P removal efficiency by harvest of Phragmites and Typha shoots in October increased with increasing HRT, despite the opposite HRT effect on N and P standing stocks. This removal through harvest appeared to be useful in treatment wetlands with N and P mass loading rates lower than approximately 120 g N m(-2) yr(-1) and 30 g P m(-2) yr(-1), corresponding to a HRT of roughly 9 days in the ditches of this wetland system. At the HRT of 9.3 days, the annual mass input to the ditches was reduced through the harvest by 7.0-11% and 4.5 -9.2% for N and P, respectively. At the higher nutrient mass loading rates, the nutrient removal through harvest was insignificant compared to the mass inputs. The vitality of Phragmites and Typha, measured as maximum aboveground biomass, was not affected by the annual cutting of the shoots in autumn over two years. The Typha stands yielded higher N and P removal efficiencies through shoot harvest than the Phragmites stands, which was largely the result of lower decreases in N and P standing stocks between August and October. This difference in nutrient standing stocks between the two species was caused by a combined effect of greater decreases in nutrient concentrations largely due to higher nutrient retranslocation efficiencies of

  3. Nutrient removal by Chlorella vulgaris F1068 under cetyltrimethyl ammonium bromide induced hormesis. (United States)

    Zhou, Qiongzhi; Li, Feng; Ge, Fei; Liu, Na; Kuang, Yangduo


    Toxicants are generally harmful to biotechnology in wastewater treatment. However, trace toxicant can induce microbial hormesis, but to date, it is still unknown how this phenomenon affects nutrient removal during municipal wastewater treatment process. Therefore, this study focused on the effects of hormesis induced by cetyltrimethyl ammonium bromide (CTAB), a representative quaternary ammonium cationic surfactant, on nutrient removal by Chlorella vulgaris F1068. Results showed that when the concentration of CTAB was less than 10 ng/L, the cellular components chlorophyll a, proteins, polysaccharides, and total lipids increased by 10.11, 58.17, 38.78, and 11.87 %, respectively, and some enzymes in nutrient metabolism of algal cells, such as glutamine synthetase (GS), acid phosphatase (ACP), H(+)-ATPase, and esterase, were also enhanced. As a result, the removal efficiencies of ammonia nitrogen (NH4 (+)) and total phosphorus (TP) increased by 14.66 and 8.51 %, respectively, compared to the control during a 7-day test period. The underlying mechanism was mainly due to an enhanced photosynthetic activity of C. vulgaris F1068 indicated by the increase in chlorophyll fluorescence parameters (the value of Fv/Fm, ΦII, Fv/Fo, and rETR increased by 12.99, 7.56, 25.59, and 8.11 %, respectively) and adenylate energy charge (AEC) (from 0.68 to 0.72). These results suggest that hormesis induced by trace toxicants could enhance the nutrient removal, which would be further considered in the design of municipal wastewater treatment processes. Graphical abstract The schematic mechanism of C. vulgaris F1068 under CTAB induced hormesis. Green arrows ( ) represent the increase and the red arrow ( ) represents the decrease.

  4. Nutrient removal from an anaerobic membrane bioreactor effluent using microalgae. Study and modeling of the process.


    Ruiz Martínez, Ana


    [EN] Anaerobic membrane bioreactors for urban wastewater treatment present interesting advantages when compared with aerobic treatments, such as less sludge production, lower energy demand and biogas generation. However, the generated effluent cannot generally be discharged without further ammonium and phosphate elimination. This thesis studies the removal of these inorganic nutrients by means of microalgae cultivation. The main objective of this work is therefore to obtain an autochthono...

  5. Role of extracellular exopolymers on biological phosphorus removal

    Institute of Scientific and Technical Information of China (English)

    LIU Ya-nan; XUE Gang; YU Shui-li; ZHAO Fang-bo


    Three sequencing batch reactors supplied with different carbon sources were investigated. The system supplied with glucose gained the best enhanced biological phosphorus removal although all of the three reactors were seeded from the same sludge. With the measurement of poly-β-hydroxyalkanoate (PHA) concentration, phosphorus content in sludge and extracellular exopolymers (EPS) with scanning electron microscopy (SEM) combined with energy dispersive spectrometry (EDS), it was found that the biosorption effect of EPS played an important role in phosphorus removal and that the amount of PHA at the end of anaerobic phase was not the only key factor to determine the following phosphorus removal efficiency.

  6. The removal of nutrients from non-point source wastewater by a hybrid bioreactor. (United States)

    Wu, Yonghong; Hu, Zhengyi; Yang, Linzhang; Graham, Bruce; Kerr, Philip G


    The aim of this project was to establish an economical and environmentally benign biotechnology for removing nutrients from non-point source wastewater. The proposal involves a hybrid bioreactor comprised of sequential anaerobic, anoxic and aerobic (A(2)/O) processes and an eco-ditch being constructed and applied in a suburban area, Kunming, south-western China, where wastewater was discharged from an industrial park and suburban communities. The results show that the hybrid bioreactor fosters heterotrophic and autotrophic microorganisms. When the hydraulic load is 200 m(3) per day with the running mode in 12h cycles, the removal efficiencies of the nutrients were 81% for TP, 74% for TDP, 82% for TN, 79% for NO(3)-N and 86% for NH(4)-N. The improved bacterial community structure and bacterial habitats further implied enhanced water quality and indicates that the easily-deployed, affordable and environmentally-friendly hybrid bioreactor is a promising bio-measure for removing high loadings of nutrients from non-point source wastewater.

  7. Controlled biomass removal - the key parameter to achieve enhanced biological phosphorus removal in biofilm systems

    DEFF Research Database (Denmark)

    Morgenroth, E.


    In contrast to enhanced biological phosphorus removal (EBPR) in activated sludge systems mass transfer processes have a major influence on overall phosphorus removal in biofilm reactors. Based on results from a laboratory scale sequencing batch biofilm reactor (SBBR) and from a mathematical model......) had only a minor effect on overall phosphorus removal. Soluble components fully penetrate the biofilm at certain times during the SBBR cycle as a consequence of SBBR operation with large concentration variations over the cycle time. The limiting processes for EBPR is the efficient removal...... of phosphorus rich biomass from the reactor. Biomass at the base of the biofilm that is not removed during backwashing will release accumulated phosphorus due to lysis or endogenous respiration and will not contribute to net phosphorus removal. For efficient operation of EBPR in biofilm systems regular...

  8. Boosted Regression Tree Models to Explain Watershed Nutrient Concentrations and Biological Condition (United States)

    Boosted regression tree (BRT) models were developed to quantify the nonlinear relationships between landscape variables and nutrient concentrations in a mesoscale mixed land cover watershed during base-flow conditions. Factors that affect instream biological components, based on ...

  9. Sludge Retention Time as a Suitable Operational Parameter to Remove Both Estrogen and Nutrients in an Anaerobic-Anoxic-Aerobic Activated Sludge System. (United States)

    Zeng, Qingling; Li, Yongmei; Yang, Shijia


    Estrogen in wastewater are responsible for a significant part of the endocrine-disrupting effects observed in the aquatic environment. The effect of sludge retention time (SRT) on the removal and fate of 17β-estradiol (E2) and 17α-ethinylestradiol (EE2) in an anaerobic-anoxic-oxic activated sludge system designed for nutrient removal was investigated by laboratory-scale experiments using synthetic wastewater. With a hydraulic retention time of 8 h, when SRT ranged 10-25 days, E2 was almost completely removed from water, and EE2 removal efficiency was 65%-81%. Both estrogens were easily sorbed onto activated sludge. Distribution coefficients (Kd) of estrogens on anaerobic sludge were greater than those on anoxic and aerobic sludges. Mass balance calculation indicated that 99% of influent E2 was degraded by the activated sludge process, and 1% remained in excess sludge; of influent EE2, 62.0%-80.1% was biodegraded; 18.9%-34.7% was released in effluent; and 0.88%-3.31% remained in excess sludge. Optimal SRT was 20 days for both estrogen and nutrient removal. E2 was almost completely degraded, and EE2 was only partly degraded in the activated sludge process. Residual estrogen on excess sludge must be considered in the sludge treatment and disposal processes. The originality of the work is that removal of nutrients and estrogens were linked, and optimal SRT for both estrogen and nutrient removal in an enhanced biological phosphorus removal system was determined. This has an important implication for the design and operation of full-scale wastewater treatment plants.

  10. Benchmarking Combined Biological Phosphorus and Nitrogen Removal Wastewater Treatment Processes

    DEFF Research Database (Denmark)

    Gernaey, Krist; Jørgensen, Sten Bay


    This paper describes the implementation of a simulation benchmark for studying the influence of control strategy implementations on combined nitrogen and phosphorus removal processes in a biological wastewater treatment plant. The presented simulation benchmark plant and its performance criteria...... are to a large extent based on the already existing nitrogen removal simulation benchmark. The paper illustrates and motivates the selection of the treatment plant lay-out, the selection of the biological process model, the development of realistic influent disturbance scenarios for dry, rain and storm weather...... conditions respectively, the definition of performance indexes that include the phosphorus removal processes, and the selection of a suitable operating point for the plant. Two control loops were implemented: one for dissolved oxygen control using the oxygen transfer coefficient K(L)a as manipulated variable...

  11. Biological removal of phenol from wastewaters: a mini review (United States)

    Pradeep, N. V.; Anupama, S.; Navya, K.; Shalini, H. N.; Idris, M.; Hampannavar, U. S.


    Phenol and its derivatives are common water pollutants and include wide variety of organic chemicals. Phenol poisoning can occur by skin absorption, inhalation, ingestion and various other methods which can result in health effects. High exposures to phenol may be fatal to human beings. Accumulation of phenol creates toxicity both for flora and fauna. Therefore, removal of phenol is crucial to perpetuate the environment and individual. Among various treatment methods available for removal of phenols, biodegradation is environmental friendly. Biological methods are gaining importance as they convert the wastes into harmless end products. The present work focuses on assessment of biological removal (biodegradation) of phenol. Various factors influence the efficiency of biodegradation of phenol such as ability of the microorganism, enzymes involved, the mechanism of degradation and influencing factors. This study describes about the sources of phenol, adverse effects on the environment, microorganisms involved in the biodegradation (aerobic and anaerobic) and enzymes that polymerize phenol.

  12. Biomass production and nutrients removal by a new microalgae strain Desmodesmus sp. in anaerobic digestion wastewater. (United States)

    Ji, Fang; Liu, Ying; Hao, Rui; Li, Gang; Zhou, Yuguang; Dong, Renjie


    Anaerobic digestion wastewater (ADW), which contains large amount of nitrogen and phosphorus, particularly high concentration of ammonium, might lead to severely environmental pollution. A new unicellular green microalgae species from a wetland at the Olympic Forest Park, Beijing, China was screened based on its growth rates and nutrients removal capability under ADW. Results of 18s rDNA and ITS1 analysis indicated that this strain have a close relationship with Desmodesmus sp., named as EJ9-6. Desmodesmus sp. EJ9-6 could remove 100% NH4-N (68.691mg/L), TP (4.565mg/L) and PO4-P (4.053mg/L), and 75.50% TN (84.236mg/L) at 10.0% ADW, which the highest biomass production was 0.412g/L after 14d cultivation. Maximum nutrients removal was observed at 10.0% ADW with daily removal rates of TN, NH4-N, TP and PO4-P at 4.542, 5.284, 0.326 and 0.290mg/L/d, respectively.

  13. Nutrients removal and recovery from anaerobically digested swine wastewater by struvite crystallization without chemical additions. (United States)

    Song, Yong-Hui; Qiu, Guang-Lei; Yuan, Peng; Cui, Xiao-Yu; Peng, Jian-Feng; Zeng, Ping; Duan, Liang; Xiang, Lian-Cheng; Qian, Feng


    Anaerobically digested swine wastewater contains high concentrations of phosphorus (P) and nitrogen (N). A pilot-scale experiment was carried out for nutrients removal and recovery from anaerobically digested swine wastewater by struvite crystallization. In the pilot plant, a sequencing batch reactor (SBR) and a continuous-flow reactor with struvite accumulation devices were designed and employed. The wastewater pH value was increased by CO(2) stripping, and the struvite crystallization process was performed without alkali and Mg(2+) additions. Results of the long-term operation of the system showed that, both reactors provided up to 85% P removal and recovery over wide ranges of aeration times (1.0-4.0 h), hydraulic retention times (HRT) (6.0-15.0 h) and temperatures (0-29.5°C) for an extended period of 247 d, in which approximate 30% of P was recovered by the struvite accumulation devices. However, 40-90% of NH(4)(+)-N removed was through air stripping instead of being immobilized in the recovered solids. The recovered products were detected and analyzed by scanning electron microscope (SEM), X-ray diffraction (XRD) and chemical methods, which were proved to be struvite with purity of more than 90%. This work demonstrated the feasibility and effects of nutrients removal and recovery from anaerobically digested swine wastewater by struvite crystallization without chemical additions.

  14. Protozoan biomass relation to nutrient and chemical oxygen demand removal in activated sludge mixed liquor. (United States)

    Akpor, Oghenerobor B; Momba, Maggy N B; Okonkwo, Jonathan O


    The relationship between biomass concentration to nutrient and chemical oxygen demand (COD) removal in mixed liquor supplemented with sodium acetate was investigated, using three protozoan isolates and three different initial biomass concentrations (10(1), 10(2) and 10(3) cells/mL). The study was carried out in a shaking flask environment at a shaking speed of 100 rpm for 96 h at 25 degrees C. Aliquot samples were taken periodically for the determination of phosphate, nitrate, COD and dissolved oxygen, using standard methods. The results revealed remarkable phosphate removal of 82-95% at biomass concentration of 10(3)cells/mL. A high nitrate removal of over 87% was observed at all initial biomass concentration in mixed liquor. There was an observed COD increase of over 50% in mixed liquor in at the end of 96-h incubation and this was irrespective of initial biomass concentration used for inoculation. The study shows the trend in nutrient and COD removal at different biomass concentrations of the test isolates in mixed liquor.

  15. Growth of three microalgae strains and nutrient removal from an agro-zootechnical digestate. (United States)

    Franchino, Marta; Comino, Elena; Bona, Francesca; Riggio, Vincenzo A


    In this paper three microalgae strains (Neochloris oleoabundans, Chlorella vulgaris and Scenedesmus obliquus) were cultivated on an agro-zootechnical digestate in comparable conditions. The material used as growth media was obtained from a pilot plant anaerobic digestor used to digest several mixes of cattle slurry and raw cheese whey. The main aims were to compare the algae growth, their tolerance with respect to the various dilutions of digestate, their nutrient removal efficiency and their role in the transformation of nitrogen compounds. C. vulgaris presented the highest elimination capacity of ammonium in 1:10 digestate sample; it was also observed that only 4% of ammonia was removed with stripping, microalgal and bacterial consortium recovered the remaining 96%. The three strains almost completely removed different nitrogen forms and phosphate in 11d. The results show that microalgal biomass production offers real opportunities for addressing issues such CO2 sequestration, biofuel production and wastewater treatment.

  16. Biological nitrate removal using wheat straw and PLA as substrate. (United States)

    Fan, Zhenxing; Hu, Jun; Wang, Jianlong


    Biological nitrate removal using wheat straw and polylactic acid (PLA) as both carbon source and biofilm support was investigated. The results showed that biofilm could develop on the surface of wheat straw within 15 d, the denitrification rate was 0.067 mg-N/(g-wheat straw x h) and nitrate removal efficiency was about 100%. For PLA, the time required for biofilm development was 40 d, the denitrification rate was 0.0026 mg-N/(g-PLA x h) and nitrate removal efficiency could also reach 100%. Temperature had a substantial influence on the denitrification performance of both wheat straw and PLA. The FTIR analysis and SEM observation confirmed that wheat straw and PLA were used for denitrification, and explained some reasons for the differences between the two substrates. The wheat straw was superior to PLA when used as carbon source for nitrate removal, in terms of the denitrification rate.

  17. Removal of geosmin and 2-methylisoborneol by biological filtration. (United States)

    Elhadi, S L N; Huck, P M; Slawson, R M


    The quality of drinking water is sometimes diminished by the presence of certain compounds that can impart particular tastes or odours. One of the most common and problematic types of taste and odour is the earthy/musty odour produced by geosmin (trans-1, 10-dimethyl-trans-9-decalol) and MIB (2-methylisoborneol). Taste and odour treatment processes including powdered activated carbon, and oxidation using chlorine, chloramines, potassium permanganate, and sometimes even ozone are largely ineffective for reducing these compounds to below their odour threshold concentration levels. Ozonation followed by biological filtration, however, has the potential to provide effective treatment. Ozone provides partial removal of geosmin and MIB but also creates other compounds more amenable to biodegradation and potentially undesirable biological instability. Subsequent biofiltration can remove residual geosmin and MIB in addition to removing these other biodegradable compounds. Bench scale experiments were conducted using two parallel filter columns containing fresh and exhausted granular activated carbon (GAC) media and sand. Source water consisted of dechlorinated tap water to which geosmin and MIB were added, as well as, a cocktail of easily biodegradable organic matter (i.e. typical ozonation by-products) in order to simulate water that had been subjected to ozonation prior to filtration. Using fresh GAC, total removals of geosmin ranged from 76 to 100% and total MIB removals ranged from 47% to 100%. The exhausted GAC initially removed less geosmin and MIB but removals increased over time. Overall the results of these experiments are encouraging for the use of biofiltration following ozonation as a means of geosmin and MIB removal. These results provide important information with respect to the role biofilters play during their startup phase in the reduction of these particular compounds. In addition, the results demonstrate the potential biofilters have in responding to

  18. Biological phosphorus and nitrogen removal in a single sludge system

    Energy Technology Data Exchange (ETDEWEB)

    Carlsson, Hans


    The primary aim of this thesis was to investigate the process stability of a single sludge activated system designed for the combined operation of enhanced biological phosphorus removal (EBPR) and nitrogen removal. A pilot plant at the Sjoelunda wastewater treatment plant in Malmoe, Sweden, has formed the basis for the investigation. The pilot plant study showed that the concentration of total phosphorus on average was low in the effluent, below 0.5 mg P/l. Simultaneously with the highest concentrations of phosphorus in the effluent, the lowest COD/P ratios in the effluent were recorded. A recurrent pattern of high concentrations of phosphorus was observed every year in July, which is the industrial holiday month in Sweden. Other instances of increased phosphorus concentrations in the secondary effluent illustrate the effect of prolonged periods of rain. Increasing flow rates due to rain lead to a dilution and a change in the composition of the COD in the influent wastewater. The COD/P and VFA/P ratios decrease with decreasing concentrations of COD. It was also shown that high removal ratios of both nitrogen and phosphorus during long periods are possible. The nitrogen removal was stable during the whole investigated period, whereas the phosphorus removal was unstable during prolonged periods with low concentrations of COD in the influent water. The combined biological phosphorus and nitrogen removal process implies that during these periods the risk of recirculating nitrate to the anaerobic reactor increases. Such a recirculation both stabilizes the nitrogen removal and withdraws some of the readily degradable organic material from the bio-P bacteria. The main conclusion of this study is that a phosphorus limited EBPR process can cope with the day to day variations, but occasionally, measures have to be taken if the demands for phosphorus removal are stringent. 49 refs, 8 figs, 1 tab

  19. The Potential Role of Urban Forests in Removing Nutrients from Stormwater. (United States)

    Denman, E C; May, P B; Moore, G M


    Biofiltration systems can be used to improve the quality of stormwater by treating runoff using plants grown in a moderately permeable soil. Most biofilters use herbaceous species, but in highly urbanized locations, such as streets, trees may be a more suitable vegetation. Biofilters that use urban woody vegetation are less studied. This experiment investigated the use of four street tree species [ Schauer, (R. Br.) Peter G. Wilson & J.T. Waterh., (Sm.) Colvill ex Sweet, and L.] and an unplanted control in model biofilters. All four tree species are used in urban landscapes in southern Australia and were chosen to investigate potential species differences in biofiltration systems. The trees were grown in mesocosms as a randomized block factorial design in soils with three saturated hydraulic conductivity rates (4, 95, and 170 mm h). The trees were regularly flooded with mains water (tap water) or artificial stormwater. Tree growth and nutrient removal performance of the systems were investigated over 13 mo. All four species grew well in all three soils, including one chosen for its low, and potentially growth-limiting, drainage rate. Tree growth increased significantly, except for , when flooded with stormwater. Unplanted controls were a source of nutrients; however, the presence of trees reduced oxidized nitrogen and filterable reactive phosphorus concentrations in leachate. There was little effect of species on the removal of nutrients from stormwater. Trees have the potential to be effective elements in urban biofiltration systems, but further field-level evaluation of these systems is required to fully assess this potential.

  20. 木薯酒糟及其厌氧发酵液作为外加碳源强化城市生活污水生物营养盐去除研究%Cassava stillage and its anaerobic fermentation liquid as external carbon sources in biological nutrient removal

    Institute of Scientific and Technical Information of China (English)

    Fan BU; Xiang HU; Li XIE; Qi ZHOU


      结论:(1)在整个试验过程中,与乙酸钠作为碳源相比,木薯酒糟及其厌氧发酵液在相同的运行条件下取得了更高的总氮( TN )去除率,分别为(72.4±3.2)%和(73.2±2.6)%,高于乙酸钠的(62.6±3.5)%。NUR 试验结果表明,木薯酒糟及其厌氧发酵液污泥的反硝化速率分别为5.49~5.99 g N/(kg MLVSS·h)和6.63~6.81 g N/(kg MLVSS·h),与其他研究中报道的食品工业废水的反硝化速率相当或略高。(2)以木薯酒糟及其厌氧发酵液作为碳源的系统发生了显著的反硝化聚磷现象,两体系中的反硝化聚磷菌分别占总聚磷菌的62.6%(86天)和61.8%(65天)。(3)以木薯酒糟上清液及其厌氧发酵液作为碳源的生物营养盐去除(SBR)系统均取得了良好稳定的脱氮除磷效果。在 BNR 工艺中投加木薯酒糟及其厌氧碱性发酵液作为外加碳源,不仅可以提高系统氮磷去除效果,还能解决这部分废水的处理问题,是一种很有潜力的替代碳源。%The aim of this study was to investigate the effects of one kind of food industry effluent, cassava stillage and its anaerobic fermentation liquid, on biological nutrient removal (BNR) from municipal wastewater in anaerobic-anoxic-aerobic sequencing batch reactors (SBRs). Experiments were carried out with cassava stillage supernatant and its anaerobic fermentation liquid, and one pure compound (sodium acetate) served as an external carbon source. Cyclic studies indicated that the cassava by-products not only affected the transformation of nitrogen, phosphorus, poly-β-hydroxyalkanoates (PHAs), and glycogen in the BNR process, but also resulted in higher removal efficiencies for phosphorus and nitrogen compared with sodium acetate. Furthermore, assays for phosphorus accumulating or-ganisms (PAOs) and denitrifying phosphorus accumulating organisms (DPAOs) demonstrated that the proportion of DPAOs to PAOs reached 62.6% (Day 86) and

  1. Efficiency and kinetic modeling of removal of nutrients and organic matter from a full-scale constructed wetland in Qasre-Shirin, Iran

    Directory of Open Access Journals (Sweden)

    Abdolmajid Gholizadeh


    Full Text Available Background: This study assessed the removal of organic material and nutrients from full-scale subsurface flow (SSF constructed wetlands (CWs followed by anaerobic stabilization ponds under environmental conditions. Methods: The effluents were distributed evenly in 12 reed beds. Samples were taken twice monthly for a total of 6 months from several points in the wetland. Biochemical oxygen demand (BOD, chemical oxygen demand (COD, total suspended solids (TSS, and nutrient removal from the system and the longitudinal effect of the reed beds for removal of pollutions were determined. A full-scale model of flow, BOD, and nutrients in SSF in the CWs is presented. Results: The flow rate and concentrations of parameters indicated that removal of organic matter and nutrients in the cold months decreased rather than in the hot months, as expected. The removal efficiency for BOD, COD, and TSS and the strongest biological interactions showed no uniform trends. The beds showed the highest removal rates in the first few meters of bed. The hybrid Monod-Plug flow regime and the Stover-Kincannon models showed the best fit for the kinetics of the processes. Umax in the Stover-Kincannon model was 3.64 mg/l.d for nitrogen and 0.24 mg/l.d for phosphorus. These values are very low, which indicates lower consumption and inefficiency of the system for removing nitrogen and phosphorus. Conclusion: It can be concluded that the SSF in CWs are able to treat average wastewater as effectively as common mechanical systems at lower cost.

  2. Removal of nutrients and veterinary antibiotics from swine wastewater by a constructed macrophyte floating bed system. (United States)

    Xian, Qiming; Hu, Lixia; Chen, Hancheng; Chang, Zhizhou; Zou, Huixian


    The potential of three varieties of Italian ryegrass (Lolium multiflorum Lam.), Dryan, Tachimasari and Waseyutaka, to improve the water quality of swine wastewater was evaluated using a constructed macrophyte floating bed system. With respect to reductions in levels of nutrients, chemical oxygen demand (COD), and sulfonamide antimicrobials (SAs, including sulfadiazine, sulfamethazine, and sulfamethoxazole), Dryan performed better than Tachimasari and Waseyutaka. For Dryan, total N was reduced by 84.0%, total P by 90.4%, COD by 83.4% and sulfonamide antimicrobials by 91.8-99.5%. Similar results were observed for Tachimasari and Waseyutaka. The results indicated that the treatment of swine wastewater using the constructed macrophyte floating bed system was effective in the removal of nutrients and veterinary antibiotics.

  3. Mixed Wastewater Coupled with CO2 for Microalgae Culturing and Nutrient Removal. (United States)

    Yao, Lili; Shi, Jianye; Miao, Xiaoling


    Biomass, nutrient removal capacity, lipid productivity and morphological changes of Chlorella sorokiniana and Desmodesmus communis were investigated in mixed wastewaters with different CO2 concentrations. Under optimal condition, which was 1:3 ratio of swine wastewater to second treated municipal wastewater with 5% CO2, the maximum biomass concentrations were 1.22 g L-1 and 0.84 g L-1 for C. sorokiniana and D. communis, respectively. Almost all of the ammonia and phosphorus were removed, the removal rates of total nitrogen were 88.05% for C. sorokiniana and 83.18% for D. communis. Lipid content reached 17.04% for C. sorokiniana and 20.37% for D. communis after 10 days culture. CO2 aeration increased intracellular particle numbers of both microalgae and made D. communis tend to be solitary. The research suggested the aeration of CO2 improve the tolerance of microalgae to high concentration of NH4-N, and nutrient excess stress could induce lipid accumulation of microalgae.

  4. Mixed Wastewater Coupled with CO2 for Microalgae Culturing and Nutrient Removal (United States)

    Yao, Lili; Shi, Jianye; Miao, Xiaoling


    Biomass, nutrient removal capacity, lipid productivity and morphological changes of Chlorella sorokiniana and Desmodesmus communis were investigated in mixed wastewaters with different CO2 concentrations. Under optimal condition, which was 1:3 ratio of swine wastewater to second treated municipal wastewater with 5% CO2, the maximum biomass concentrations were 1.22 g L-1 and 0.84 g L-1 for C. sorokiniana and D. communis, respectively. Almost all of the ammonia and phosphorus were removed, the removal rates of total nitrogen were 88.05% for C. sorokiniana and 83.18% for D. communis. Lipid content reached 17.04% for C. sorokiniana and 20.37% for D. communis after 10 days culture. CO2 aeration increased intracellular particle numbers of both microalgae and made D. communis tend to be solitary. The research suggested the aeration of CO2 improve the tolerance of microalgae to high concentration of NH4-N, and nutrient excess stress could induce lipid accumulation of microalgae. PMID:26418261

  5. Mixed Wastewater Coupled with CO2 for Microalgae Culturing and Nutrient Removal.

    Directory of Open Access Journals (Sweden)

    Lili Yao

    Full Text Available Biomass, nutrient removal capacity, lipid productivity and morphological changes of Chlorella sorokiniana and Desmodesmus communis were investigated in mixed wastewaters with different CO2 concentrations. Under optimal condition, which was 1:3 ratio of swine wastewater to second treated municipal wastewater with 5% CO2, the maximum biomass concentrations were 1.22 g L-1 and 0.84 g L-1 for C. sorokiniana and D. communis, respectively. Almost all of the ammonia and phosphorus were removed, the removal rates of total nitrogen were 88.05% for C. sorokiniana and 83.18% for D. communis. Lipid content reached 17.04% for C. sorokiniana and 20.37% for D. communis after 10 days culture. CO2 aeration increased intracellular particle numbers of both microalgae and made D. communis tend to be solitary. The research suggested the aeration of CO2 improve the tolerance of microalgae to high concentration of NH4-N, and nutrient excess stress could induce lipid accumulation of microalgae.

  6. The investigation of effect of organic carbon sources addition in anaerobic-aerobic (low dissolved oxygen) sequencing batch reactor for nutrients removal from wastewaters. (United States)

    Zheng, Xiong; Tong, Juan; Li, Hongjing; Chen, Yinguang


    The effect of addition of organic carbon sources (acetic acid and waste activated sludge alkaline fermentation liquid) on anaerobic-aerobic (low dissolved oxygen, 0.15-0.45 mg/L) biological municipal wastewater treatment was investigated. The results showed that carbon source addition affected not only the transformations of polyhydroxyalkanoates (PHA), glycogen, nitrogen and phosphorus, but the net removal of nitrogen and phosphorus. The removal efficiencies of TN and TP were, respectively, 61% and 61% without organic carbon source addition, 81% and 95% with acetic acid addition, and 83% and 97% with waste activated sludge alkaline fermentation liquid addition. It seems that the alkaline fermentation liquid of waste biosolids generated in biological wastewater treatment plant can be used to replace acetic acid as an additional carbon source to improve the anaerobic-aerobic (low dissolved oxygen) municipal wastewater nutrients removal although its use was observed to cause a slight increase of effluent BOD and COD concentrations.

  7. A high loading overland flow system: Impacts on soil characteristics, grass constituents, yields and nutrient removal. (United States)

    Wen, C G; Chen, T H; Hsu, F H; Lu, C H; Lin, J B; Chang, C H; Chang, S P; Lee, C S


    The objectives of this paper are to determine effects of different grass species and their harvests on pollutant removal, elucidate impacts on soil characteristics and grass constituents, observe grass yield and quantify nutrient uptake by vegetation in an overland flow system (OLFS). Polluted creek water was applied to eight channels in the OLFS, which were planted with Paragrass, Nilegrass, Cattail, and Vetiver, with each two channels being randomly planted with a given grass species. The grass in one channel was harvested while that in the other channel was not. At a high rate of 27.8 m d(-1) hydraulic loading, the removal efficiencies of conventional pollutants such as BOD, COD, suspended solids (SS), and total coliforms in wastewater are not affected by the type of the grasses species, but those of nitrogen and phosphorus are affected by different species. Overall average removal efficiencies of BOD, COD, SS, ammonia, total nitrogen, total phosphorus and total coliforms through the OLFS are 42%, 48%, 78%, 47%, 40%, 33% and 89%, respectively. The concentration of nitrate, however, increases due to nitrification. Soil characteristics in OLFS have been changed significantly; specific conductivity, organic matter, exchangeable magnesium, extractable copper and zinc in soils all increase with time while pHs decrease. During the winter season, there is a significant accumulation of nitrate in grass with the subsequent reduction during the active growing season (Spring). The contents of nitrate and phosphorus in grass tissue are higher than those of grass in general pastureland, probably due to nutrient luxury uptake by grass. The overall grass yield, growth rate and nutrient uptake are quantified and implication of such high rate OLFS discussed.

  8. High-latitude controls of thermocline nutrients and low latitude biological productivity. (United States)

    Sarmiento, J L; Gruber, N; Brzezinski, M A; Dunne, J P


    The ocean's biological pump strips nutrients out of the surface waters and exports them into the thermocline and deep waters. If there were no return path of nutrients from deep waters, the biological pump would eventually deplete the surface waters and thermocline of nutrients; surface biological productivity would plummet. Here we make use of the combined distributions of silicic acid and nitrate to trace the main nutrient return path from deep waters by upwelling in the Southern Ocean and subsequent entrainment into subantarctic mode water. We show that the subantarctic mode water, which spreads throughout the entire Southern Hemisphere and North Atlantic Ocean, is the main source of nutrients for the thermocline. We also find that an additional return path exists in the northwest corner of the Pacific Ocean, where enhanced vertical mixing, perhaps driven by tides, brings abyssal nutrients to the surface and supplies them to the thermocline of the North Pacific. Our analysis has important implications for our understanding of large-scale controls on the nature and magnitude of low-latitude biological productivity and its sensitivity to climate change.

  9. Simultaneous carbon and nitrogen removal in anoxic-aerobic circulating fluidized bed biological reactor (CFBBR). (United States)

    Cui, Y; Nakhla, G; Zhu, J; Patel, A


    Biological nutrient removal (BNR) in municipal wastewater treatment to remove carbonaceous substrates and nutrients, has recently become increasingly popular worldwide due to increasingly stringent regulations. Biological fluidized bed (BFB) technology, which could be potentially used for BNR, can provide some advantages such as high efficiency and a compact structure. This work shows the results of simultaneous elimination of organic carbon and nitrogen using a circulating fluidized bed biological reactor (CFBBR, which has been developed recently for chemical engineering processes. The CFBBR has two fluidized beds, running as anoxic and aerobic processes to accomplish simultaneous nitrification and denitrification, with continuous liquid recirculation through the anoxic bed and the aerobic bed. Soluble COD concentrations in the effluent ranging from 4 to 20 mg l(-1) were obtained at varying COD loading rates; ammonia nitrogen removal efficiencies averaged in excess of 99% at a minimum total hydraulic retention time (HRT) of 2.0 hours over a temperature range of 25 degrees C to 28 degrees C. Effluent nitrate nitrogen concentration of less than 5 mg l(-1) was achieved by increasing effluent recycle rate. No nitrite accumulation was observed either in the anoxic bed or in the aerobic bed. The system was able to treat grit chamber effluent wastewater at a HRT of 2.0 hours while achieving average effluent BOD, COD, NH3-N, TKN, nitrates, total phosphate, TSS and VSS concentrations of 10 mg l(-1), 18 mg l(-1), 1.3 mg l(-1), 1.5 mg l(-1), 7 mg l(-1), 2.0 mg l(-1), 10 mg l(-1) and 8 mg l(-1) respectively. The CFBBR appears to be not only an excellent alternative for conventional activated sludge type BNR technologies but also capable of processing much higher loadings that are suitable for industrial applications.

  10. Leaching techniques to remove metals and potentially hazardous nutrients from trout farm sludge. (United States)

    Jung, I S; Lovitt, R W


    A fish farm sludge high in P (2-6% w/w as dry matter), Fe (5-7%), C (40-50%) and N (0.8-4%) was subjected to a series of acid leaching treatments using HCl, organic acids, and biologically mediated acid production. Additions of biodegradable organic acid solubilized heavy metals better than HCl, while additions of 1.5% w/v glucose followed by 7 day incubation stabilized the sludge releasing 92% P, 100% Fe. The use of homo-lactic Lactobacillus plantarum starter cultures were more effective than hetero-lactic Lactobacillus buchneri, solubilizing 81.9% P, 92.2% Fe, 93.0% Zn and 96.4% Ca in the sludge. The anaerobic sludge-glucose fermentation using L. plantarum produced a leached sludge that has low heavy metal and nutrient content while affording the recovery of nutrients. The potential of these methods for practical application are briefly discussed.

  11. Effects of two different nutrient loads on microalgal production, nutrient removal and photosynthetic efficiency in pilot-scale wastewater high rate algal ponds. (United States)

    Sutherland, Donna L; Turnbull, Matthew H; Broady, Paul A; Craggs, Rupert J


    When wastewater treatment high rate algal ponds (HRAP) are coupled with resource recovery processes, such as biofuel production, short hydraulic retention times (HRTs) are often favoured to increase the microalgal biomass productivity. However, short HRT can result in increased nutrient load to the HRAP which may negatively impact on the performance of the microalgae. This paper investigate the effects of high (NH4-N mean concentration 39.7 ± 17.9 g m(-3)) and moderate ((NH4-N mean concentration 19.9 ± 8.9 g m(-3)) nutrient loads and short HRT on the performance of microalgae with respect to light absorption, photosynthesis, biomass production and nutrient removal in pilot-scale (total volume 8 m(3)) wastewater treatment HRAPs. Microalgal biomass productivity was significantly higher under high nutrient loads, with a 133% and 126% increase in the chlorophyll-a and VSS areal productivities, respectively. Microalgae were more efficient at assimilating NH4-N from the wastewater under higher nutrient loads compared to moderate loads. Higher microalgal biomass with increased nutrient load resulted in increased light attenuation in the HRAP and lower light absorption efficiency by the microalgae. High nutrient loads also resulted in improved photosynthetic performance with significantly higher maximum rates of electron transport, oxygen production and quantum yield. This experiment demonstrated that microalgal productivity and nutrient removal efficiency were not inhibited by high nutrient loads, however, higher loads resulted in lower water quality in effluent discharge.

  12. Dissolved nutrients and atrazine removal by column-scale monophasic and biphasic rain garden model systems. (United States)

    Yang, Hanbae; McCoy, Edward L; Grewal, Parwinder S; Dick, Warren A


    Rain gardens are bioretention systems that have the potential to reduce peak runoff flow and improve water quality in a natural and aesthetically pleasing manner. We compared hydraulic performance and removal efficiencies of nutrients and atrazine in a monophasic rain garden design versus a biphasic design at a column-scale using simulated runoff. The biphasic rain garden was designed to increase retention time and removal efficiency of runoff pollutants by creating a sequence of water saturated to unsaturated conditions. We also evaluated the effect of C substrate availability on pollutant removal efficiency in the biphasic rain garden. Five simulated runoff events with various concentrations of runoff pollutants (i.e. nitrate, phosphate, and atrazine) were applied to the monophasic and biphasic rain gardens once every 5d. Hydraulic performance was consistent over the five simulated runoff events. Peak flow was reduced by approximately 56% for the monophasic design and 80% for the biphasic design. Both rain garden systems showed excellent removal efficiency of phosphate (89-100%) and atrazine (84-100%). However, significantly (p<0.001) higher removal of nitrate was observed in the biphasic (42-63%) compared to the monophasic rain garden (29-39%). Addition of C substrate in the form of glucose increased removal efficiency of nitrate significantly (p<0.001), achieving up to 87% removal at a treatment C/N ratio of 2.0. This study demonstrates the importance of retention time, environmental conditions (i.e. saturated/unsaturated conditions), and availability of C substrate for bioremediation of pollutants, especially nitrates, in rain gardens.

  13. Nitrification and microalgae cultivation for two-stage biological nutrient valorization from source separated urine. (United States)

    Coppens, Joeri; Lindeboom, Ralph; Muys, Maarten; Coessens, Wout; Alloul, Abbas; Meerbergen, Ken; Lievens, Bart; Clauwaert, Peter; Boon, Nico; Vlaeminck, Siegfried E


    Urine contains the majority of nutrients in urban wastewaters and is an ideal nutrient recovery target. In this study, stabilization of real undiluted urine through nitrification and subsequent microalgae cultivation were explored as strategy for biological nutrient recovery. A nitrifying inoculum screening revealed a commercial aquaculture inoculum to have the highest halotolerance. This inoculum was compared with municipal activated sludge for the start-up of two nitrification membrane bioreactors. Complete nitrification of undiluted urine was achieved in both systems at a conductivity of 75mScm(-1) and loading rate above 450mgNL(-1)d(-1). The halotolerant inoculum shortened the start-up time with 54%. Nitrite oxidizers showed faster salt adaptation and Nitrobacter spp. became the dominant nitrite oxidizers. Nitrified urine as growth medium for Arthrospira platensis demonstrated superior growth compared to untreated urine and resulted in a high protein content of 62%. This two-stage strategy is therefore a promising approach for biological nutrient recovery.

  14. Biological removal of phyto-sterols in pulp mill effluents. (United States)

    Mahmood-Khan, Zahid; Hall, Eric R


    Phyto-sterols and extractives found in pulp mill effluents are suspected to cause endocrine abnormalities in receiving water fish. The control of sterols in pulp mill effluents through biological secondary wastewater treatment was studied using two lab-scale bioreactor systems. After achieving a stable performance, both bioreactor systems successfully removed (>90%) sterols and the estimated biodegradation was up to 80%. Reactor 1 system operating at 6.7 ± 0.2 pH effectively treated pulp mill effluent sterols spiked up to 4500 μg/L in 11 h HRT and 11 day SRT. However, Reactor 2 system operating at 7.6 ± 0.2 pH performed relatively poorly. Retention time reductions beyond critical values deteriorated the performance of treatment systems and quickly reduced the sterols biodegradation. The biodegradation loss was indicated by mixed liquor sterols content that started increasing. This biodegradation loss was compensated by the increased role of bio-adsorption and the overall sterols removal remained relatively high. Hence, a relatively small (20-30%) loss in the overall sterols removal efficiency did not fully reflect the associated major (60-70%) loss in the sterols biodegradation because the amount of sterols accumulated in the sludge due to adsorption increased so the estimate of sterols removal through adsorption increased from 30-40% to 70-80% keeping the overall sterols removal still high.

  15. Nutrient removal using biosorption activated media: preliminary biogeochemical assessment of an innovative stormwater infiltration basin (United States)

    O'Reilly, Andrew M.; Wanielista, Martin P.; Chang, Ni-Bin; Xuan, Zhemin; Harris, Willie G.


    Soil beneath a stormwater infiltration basin receiving runoff from a 22.7 ha predominantly residential watershed in central Florida, USA, was amended using biosorption activated media (BAM) to study the effectiveness of this technology in reducing inputs of nitrogen and phosphorus to groundwater. The functionalized soil amendment BAM consists of a 1.0:1.9:4.1 mixture (by volume) of tire crumb (to increase sorption capacity), silt and clay (to increase soil moisture retention), and sand (to promote sufficient infiltration), which was applied to develop a prototype stormwater infiltration basin utilizing nutrient reduction and flood control sub-basins. Comparison of nitrate/chloride (NO3-/Cl-) ratios for the shallow groundwater indicate that prior to using BAM, NO3- concentrations were substantially influenced by nitrification or variations in NO3- input. In contrast, for the prototype basin utilizing BAM, NO3-/Cl- ratios indicate minor nitrification and NO3- losses with the exception of one summer sample that indicated a 45% loss. Biogeochemical indicators (denitrifier activity derived from real-time polymerase chain reaction and variations in major ions, nutrients, dissolved and soil gases, and stable isotopes) suggest NO3- losses are primarily attributable to denitrification, whereas dissimilatory nitrate reduction to ammonium is a minor process. Denitrification was likely occurring intermittently in anoxic microsites in the unsaturated zone, which was enhanced by increased soil moisture within the BAM layer and resultant reductions in surface/subsurface oxygen exchange that produced conditions conducive to increased denitrifier activity. Concentrations of total dissolved phosphorus and orthophosphate (PO43-) were reduced by more than 70% in unsaturated zone soil water, with the largest decreases in the BAM layer where sorption was the most likely mechanism for removal. Post-BAM PO43-/Cl- ratios for shallow groundwater indicate predominantly minor increases and

  16. Practice of High Concentration Sludge for Efficient Nutrient Removal from Municipal Sewage

    Institute of Scientific and Technical Information of China (English)

    LI Ang; ZHANG Yan-qiu; LI Yan


    ECOSUNIDE is a new activated sludge process based on the sludge concentration optimization theory.With it,we carried out a high sludge concentration by changing influent mode and distributing carbon source in a reasonable way,which can improve the ecological superiority of nitrification and denitrification for the growth of phosphorous accumulating organisms(PAOs)and nitrifiers and raised the nutrient removal efficiency of municipal sewage treatment plants.In 2007,we adopted this technique in Linyi Sewage Treatment Plant in Shandong Province,China.After the reconstruction,we achieved the high efficiency of nutrient removal with low investment under the dynamic load of the secondary sewage treatment plant.The effluent water qualities meet the class I-A criteria specified in Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant(GB 18918-2002)and the rest effluent indexes meet the class I-B criteria.Besides, we have above 20% operating cost cut by stopping the internal reflux without power charge increased and any new pool structures built.

  17. Removal and recovery of nutrients as struvite from anaerobic digestion residues of poultry manure. (United States)

    Yilmazel, Y D; Demirer, G N


    The removal and the recovery of nutrients, namely nitrogen (N) and phosphorus (P) from anaerobically digested and solid-liquid separated manure effluents via struvite precipitation were investigated. Both the liquid and the solid phases of the poultry manure digester effluent were subjected to struvite precipitation experiments. The Mg:N:P molar ratio of 1:1:1 in the liquid phase resulted in an average NH4-N removal efficiency of 86.4%, which increased to 97.4% by adjusting the Mg:N:P ratio to 1.5:1:1. The acidic phosphorus-dissolution process was applied to the solid phase of the effluent to obtain a phosphorus-enriched solution. Nutrient recovery experiments with NaOH as the buffering reagent were conducted with and without addition of external chemicals (Mg and P sources) to evaluate the influence of the Mg:N:P molar ratio, the Mg:P molar ratio and pH. All the experiments depicted complete PO4-P (99.6-100.0%) and partial NH4-N (3.3-65.6%) recoveries from the phosphorus-enriched solution.

  18. Identification and Control of Nutrient Removing Processes in Wastewater Treatment Plants

    DEFF Research Database (Denmark)

    Nielsen, Marinus K.; Madsen, Henrik; Carstensen, Niels Jacob


    Today the use of on-line control for wastewater treatment plants is very low. A main reason is the lack of quality of the data, and the fact that more sophisticated control strategies must be based on a model of the dynamics of the biological processes. This paper discusses the historical reasons...... for the limited use of modern control strategies for wastewater treatment plants. Today, however, on-line nutrient sensors are more reliable. In the present context the use of on-line monitored values of ammonia, nitrate and phosphate from a full scale plant are used as the background for discussing...

  19. Precooking processing of bamboo shoots for removal of anti-nutrients. (United States)

    Pandey, Ashok Kumar; Ojha, Vijayalakshmi


    Bamboo shoots being low in fat, high in dietary fiber and rich in mineral content, like an ideal vegetable have been used traditionally. Besides nutrients, bamboo shoots also contain lethal concentration of the anti-nutrient (cyanogen) that need to be removed before human consumption. Therefore an attempt has been made to find out the best processing method for confiscation of cyanogens. B. bambos, B. tulda, D. strictus and D.asper were selected for the study. Fresh and processed bamboo shoots were analyzed for their various nutritional and anti-nutritional contents. Carbohydrate content in fresh shoots of studied species ranged from 2.39%-3.6%, proteins from 1.65%-2.08%, phenols from 0.36%-0.63%, cyanogens from 0.011%-0.018%, minerals did not vary significantly among the species except potassium which ranged from 0.32%-0.52%. The shoots were processed by boiling in water and different concentrations of NaCl (1%, 5% and 10%) for different intervals (10, 15, 20 and 25 min) to achieve maximum removal of cyanogens with minimum loss of nutrients. Boiling shoots in 5% NaCl for 15 min was found to be the best method for B. bamboos, 10 min boiling in 1% NaCl for B. tulda, 15 min boiling in 1% NaCl for D. strictus and 10 min boiling in 5% NaCl for D. asper. These processing methods will be very useful in utilization of bamboo shoots as these are very simple and can be used by the local inhabitants and shoot processing industries.

  20. Including Life Cycle Assessment for decision-making in controlling wastewater nutrient removal systems. (United States)

    Corominas, Lluís; Larsen, Henrik F; Flores-Alsina, Xavier; Vanrolleghem, Peter A


    This paper focuses on the use of Life Cycle Assessment (LCA) to evaluate the performance of seventeen control strategies in wastewater treatment plants (WWTPs). It tackles the importance of using site-specific factors for nutrient enrichment when decision-makers have to select best operating strategies. Therefore, the LCA evaluation is repeated for three different scenarios depending on the limitation of nitrogen (N), phosphorus (P), or both, when evaluating the nutrient enrichment impact in water bodies. The LCA results indicate that for treated effluent discharged into N-deficient aquatic systems (e.g. open coastal areas) the most eco-friendly strategies differ from the ones dealing with discharging into P-deficient (e.g. lakes and rivers) and N&P-deficient systems (e.g. coastal zones). More particularly, the results suggest that strategies that promote increased nutrient removal and/or energy savings present an environmental benefit for N&P and P-deficient systems. This is not the case when addressing N-deficient systems for which the use of chemicals (even for improving N removal efficiencies) is not always beneficial for the environment. A sensitivity analysis on using weighting of the impact categories is conducted to assess how value choices (policy decisions) may affect the management of WWTPs. For the scenarios with only N-limitation, the LCA-based ranking of the control strategies is sensitive to the choice of weighting factors, whereas this is not the case for N&P or P-deficient aquatic systems.

  1. Nutrients' removal from aquaculture wastewater using the macroalgae Gracilaria birdiae

    Energy Technology Data Exchange (ETDEWEB)

    Marinho-Soriano, E.; Nunes, S.O.; Carneiro, M.A.A.; Pereira, D.C. [Universidade Federal do Rio Grande do Norte, Depto. de Oceanografia e Limnologia, Via Costeira, Praia de Mae Luiza, s/n, Natal, RN 59014-100 (Brazil)


    Intensive aquaculture releases large amount of nutrients into aquatic ecosystems and can lead to eutrophication of coastal waters. Studies conducted in aquaculture systems have demonstrated that the seaweeds are efficient in reducing nutrients and at the same time provides extra income, when species of economic importance are used. This study was conducted to evaluate whether Gracilaria birdiae could be cultivated efficiently for the production of useful algal biomass and removal of nutrients from shrimp pond effluents. The results obtained showed a gradual increase in biomass and relative growth rate (RGR) over the experimental period. Mean RGR between the weeks varied significantly (p < 0.01), reaching a maximum of 3.6 {+-} 0.35% d{sup -1} and a minimum of 1.6 {+-} 0.52% d{sup -1}. The mean for the whole period was 2.6% d{sup -1}. The biofiltration capacity of G. birdiae was confirmed by the significantly reduced concentration of the three nutrients analyzed (PO{sub 4}{sup 3-}, NH{sub 4}{sup +} and NO{sub 3}{sup -}) over the study period. The concentration of PO{sub 4}{sup 3-} decreased by 93.5%, NH{sub 4}{sup +} by 34% and NO{sub 3}{sup -} by 100% after the 4-week experimental period. The results obtained in this study indicated that G. birdiae can be used in aquaculture systems as a biofilter. In addition, the macroalgae biomass produced offers alternative source of raw material for the extraction of the phycocolloid agar, human food and animal feed. (author)

  2. Cultivation of Chlorella vulgaris in wastewater with waste glycerol: Strategies for improving nutrients removal and enhancing lipid production. (United States)

    Ma, Xiaochen; Zheng, Hongli; Addy, Min; Anderson, Erik; Liu, Yuhuan; Chen, Paul; Ruan, Roger


    To improve nutrients removal from wastewater and enhance lipid production, cultivation of Chlorella vulgaris in wastewater with waste glycerol generated from biodiesel production using scum derived oil as feedstock was studied. The results showed that nutrients removal was improved and lipid production of C. vulgaris was enhanced with the addition of waste glycerol into wastewater to balance its C/N ratio. The optimal concentration of the pretreated glycerol for C. vulgaris was 10gL(-1) with biomass concentration of 2.92gL(-1), lipid productivity of 163mgL(-1)d(-1), and the removal of 100% ammonia and 95% of total nitrogen. Alkaline conditions prompted cell growth and lipid accumulation of C. vulgaris while stimulating nutrients removal. The application of the integration process can lower both wastewater treatment and biofuel feedstock costs.

  3. Simultaneous removal of nutrients from milking parlor wastewater using an AO2 sequencing batch reactor (SBR) system. (United States)

    Wu, Xiao; Zhu, Jun


    The feasibility of using a lab-scale, anaerobic-aerobic-anoxic-aerobic sequencing batch reactor ((AO)2 SBR) to simultaneously remove biological organics, nitrogen and phosphorus from dairy milking parlor wastewater was investigated in this study. Three hydraulic retention times (HRT = 2.1, 2.7, and 3.5 days) and three mixing-to-process time ratios (TM/TP = 0.43, 0.57, and 0.68) were evaluated as two controlling factors using a 3 × 3 experimental design to determine the optimal combination. Results showed that the HRT of 2.7 days with TM/TP = 0.57 was the best to achieve simultaneous nutrients removal for the influent with initial soluble chemical oxygen demand (SCOD) of about 2000 mg L(-1) (only 0.55 mg L(-1) NH4-N, < 0.1 mg L(-1) nitrate, and 0.14 mg L(-1) soluble phosphorus in the effluent). Good correlations between pH and ORP, and ORP and DO, were also obtained with correlation coefficients all higher than or equal to 0.975. These relationships could be used to develop real-time control strategies to optimize the duration of each operating phase in the (AO)2 SBR system to save energy and enhance treatment efficiency.

  4. Application of electrochemical processes to membrane bioreactors for improving nutrient removal and fouling control. (United States)

    Borea, Laura; Naddeo, Vincenzo; Belgiorno, Vincenzo


    Membrane bioreactor (MBR) technology is becoming increasingly popular as wastewater treatment due to the unique advantages it offers. However, membrane fouling is being given a great deal of attention so as to improve the performance of this type of technology. Recent studies have proven that the application of electrochemical processes to MBR represents a promising technological approach for membrane fouling control. In this work, two intermittent voltage gradients of 1 and 3 V/cm were applied between two cylindrical perforated electrodes, immersed around a membrane module, at laboratory scale with the aim of investigating the treatment performance and membrane fouling formation. For comparison purposes, the reactor also operated as a conventional MBR. Mechanisms of nutrient removal were studied and membrane fouling formation evaluated in terms of transmembrane pressure variation over time and sludge relative hydrophobicity. Furthermore, the impact of electrochemical processes on transparent exopolymeric particles (TEP), proposed as a new membrane fouling precursor, was investigated in addition to conventional fouling precursors such as bound extracellular polymeric substances (bEPS) and soluble microbial products (SMP). All the results indicate that the integration of electrochemical processes into a MBR has the advantage of improving the treatment performance especially in terms of nutrient removal, with an enhancement of orthophosphate (PO4-P) and ammonia nitrogen (NH4-N) removal efficiencies up to 96.06 and 69.34 %, respectively. A reduction of membrane fouling was also observed with an increase of floc hydrophobicity to 71.72 %, a decrease of membrane fouling precursor concentrations, and, thus, of membrane fouling rates up to 54.33 %. The relationship found between TEP concentration and membrane fouling rate after the application of electrochemical processes confirms the applicability of this parameter as a new membrane fouling indicator.

  5. Removal design report for the 108-F Biological Laboratory

    Energy Technology Data Exchange (ETDEWEB)



    Most of the 100-F facilities were deactivated with the reactor and have since been demolished. Of the dozen or so reactor-related structures, only the 105-F Reactor Building and the 108-F Biology Laboratory remain standing today. The 108-F Biology Laboratory was intended to be used as a facility for the mixing and addition of chemicals used in the treatment of the reactor cooling water. Shortly after F Reactor began operation, it was determined that the facility was not needed for this purpose. In 1949, the building was converted for use as a biological laboratory. In 1962, the lab was expanded by adding a three-story annex to the original four-story structure. The resulting lab had a floor area of approximately 2,883 m{sup 2} (main building and annex) that operated until 1973. The building contained 47 laboratories, a number of small offices, a conference room, administrative section, lunch and locker rooms, and a heavily shielded, high-energy exposure cell. The purpose of this removal design report is to establish the methods of decontamination and decommissioning and the supporting functions associated with facility removal and disposal.

  6. Biological methods of dye removal from textile effluents - A review

    Directory of Open Access Journals (Sweden)

    Archna *


    Full Text Available Textile dyes are molecules designed to impart permanent colours to textile fabrics. They pose an environmental problem due to their toxicity and decrease the aesthetic value of water bodies into which they are discharged. Current physico-chemical technologies for dye removal cannot remove all classes of dyes, and two or more technologies are usually combined to achieve satisfactory decolourisation efficiencies. Direct biological treatment using fungi or bacteria can also be employed, but nutritional and physiological requirements of microorganisms put constraints on the applicability of such bioremediation processes. The search for efficient and green oxidation technologies has increased the interest in the use of enzymes to replace the conventional non-biological methods. Among the different existing oxidant enzymes, laccase (benzenediol:oxygen oxidoreductases; EC has been the subject of intensive research in the past few decades due to its low substrate specificity. Enzymatic treatment using laccase can be simpler and much more efficient than the traditional physical or chemical treatments. This paper reviews conventional biological processes as well as  laccase-based processes might replace the traditionally energy intensive and water-consuming chemical treatment operations in the textile industry. Keywords: Dyes, Decolourisation, Green Oxidation, Laccase, Textile industry  

  7. Biological removal of dimethyl sulphide from sea water (United States)

    Kiene, Ronald P.; Bates, Timothy S.


    DIMETHYL sulphide (DMS) is an important sulphur-containing trace gas in the atmosphere. It is present in oceanic surface waters at concentrations sufficient to sustain a considerable net flux of DMS from the oceans to the atmosphere, estimated to comprise nearly half of the global biogenic input of sulphur to the atmosphere1. DMS emitted from the oceans may be a precursor of tropospheric aerosols and of cloud condensation nuclei in the remote marine atmosphere, thereby affecting the Earth's radiative balance and thus its climate2-4. Relatively little is known, however, about the biogeochemical and physical processes that control the concentration of DMS in sea water. Here we present data from incubation experiments, carried out at sea, which show that DMS is removed by microbial activity. In the eastern, tropical Pacific Ocean, DMS turnover is dominated by biological processes, with turnover times for biological DMS removal generally more than ten (3-430) times faster than turnover by ventilation to the atmosphere. Thus biological consumption of DMS seems to be a more important factor than atmospheric exchange in controlling DMS concentrations in the ocean, and hence its flux to the atmosphere. These results have significant implications for climate feedback models involving DMS emissions3, and highlight the importance of the microbial food web in oceanic DMS cycling.

  8. Nutrient removal using biosorption activated media: Preliminary biogeochemical assessment of an innovative stormwater infiltration basin

    Energy Technology Data Exchange (ETDEWEB)

    O' Reilly, Andrew M., E-mail: [U.S. Geological Survey, Florida Water Science Center, 12703 Research Pkwy, Orlando, FL 32826 (United States); Wanielista, Martin P., E-mail: [University of Central Florida, Water Research Center and Stormwater Management Academy, 4000 Central Florida Blvd, Building 91, Suite 442, Orlando, FL 32816 (United States); Chang, Ni-Bin, E-mail: [University of Central Florida, Department of Civil, Environmental, and Construction Engineering, 4000 Central Florida Blvd, Building 91, Suite 442, Orlando, FL 32816 (United States); Xuan, Zhemin, E-mail: [University of Central Florida, Department of Civil, Environmental, and Construction Engineering, 4000 Central Florida Blvd, Building 91, Suite 442, Orlando, FL 32816 (United States); Harris, Willie G., E-mail: [University of Florida, Soil and Water Science Department, 2169 McCarty Hall, Gainesville, FL 32611 (United States)


    for removal. Post-BAM PO{sub 4}{sup 3-}/Cl{sup -} ratios for shallow groundwater indicate predominantly minor increases and decreases in PO{sub 4}{sup 3-} with the exception of one summer sample that indicated a 50% loss. Differences in nutrient variations between the unsaturated zone and shallow groundwater may be the result of the intensity and duration of nutrient removal processes and mixing ratios with water that had undergone little biogeochemical transformation. Observed nitrogen and phosphorus losses demonstrate the potential, as well as the future research needs to improve performance, of the innovative stormwater infiltration basin using BAM for providing passive, economical, stormwater nutrient-treatment technology to support green infrastructure. -- Highlights: Black-Right-Pointing-Pointer New technology to control nutrient leaching beneath stormwater infiltration basins. Black-Right-Pointing-Pointer Integrated nutrient reduction and flood control sub-basins. Black-Right-Pointing-Pointer Biosorption activated media (BAM) promotes sorption and soil moisture retention. Black-Right-Pointing-Pointer Soil moisture retention is key BAM function promoting biogeochemical processes. Black-Right-Pointing-Pointer Documented decreases in nitrogen and phosphorus species.

  9. Atrazine Removal from Aqueous Solutions using Submerged Biological Aerated Filter

    Directory of Open Access Journals (Sweden)

    Mohammad Ali Baghapour


    Full Text Available Atrazine is widely used in the agriculture as an herbicide. Due to its high mobility, Atrazine leaks into the groundwaters, surface waters, and drinking water wells. Many physical and chemical methods have been suggested for removing Atrazine from aquatic environments. However, these methods are very costly, have many performance problems, produce a lot of toxic intermediates which are very harmful and dangerous, and cannot completely mineralize Atrazine. In this study, biodegradation of Atrazine by microbial consortium was evaluated in the aquatic environment. In order to assess the Atrazine removal from the aquatic environment, submerged biological aerated filter (SBAF was fed with synthetic wastewater based on sucrose and Atrazine at different hydraulic retention times (HRTs. The maximum efficiencies for Atrazine and Soluble Chemical Oxygen Demand (SCOD removal were 97.9% and 98.9%, respectively. The study findings showed that Stover-Kincannon model had very good fitness (R2 > 99% in loading Atrazine in the biofilter and by increasing the initial concentration of Atrazine, the removal efficiency increased. Aerobic mixed biofilm culture was observed to be suitable for the treatment of Atrazine from aquatic environment. There was no significant inhibition effect on mixed aerobic microbial consortia. Atrazine degradation depended on the strength of wastewater and the amount of Atrazine in the influent

  10. Modified rotating biological contactor for removal of dichloromethane vapours. (United States)

    Ravi, R; Philip, Ligy; Swaminathan, T


    Bioreactors are used for the treatment of waste gas and odour that has gained much acceptance in the recent years to treat volatile organic compounds (VOCs). The different types of bioreactors (biofilter, biotrickling filter and bioscrubber) have been used for waste gas treatment. Each of these reactors has some advantages and some limitations. Though biodegradation is the main process for the removal of the pollutants, the mechanisms of removal and the microbial communities may differ among these bioreactors. Consequently, their performance or removal efficiency may also be different. Clogging of reactor and pressure drop are the main problems. In this study attempts are made to use the principle of rotating biological contactor (RBC) used for wastewater treatment for the removal of VOC. To overcome the above problem the RBC is modified which is suitable for the treatment of VOC (dichloromethane, DCM). DCM is harmful to human health and hazardous to the atmospheric environment. Modified RBC had no clogging problems and no pressure drop. So, it can handle the pollutant load for a longer period of time. A maximum elimination capacity of 25.7 g/m3 h has been achieved in this study for the DCM inlet load of 58 g/m3 h. The average biofilm thickness is 1 mm. The transient behaviour of the modified RBC treating DCM was investigated. The modified RBC is able to handle shutdown, restart and shock loading operations.

  11. Water treatment by aquatic ecosystem: Nutrient removal by reservoirs and flooded fields (United States)

    Reddy, K. R.; Sacco, P. D.; Graetz, D. A.; Campbell, K. L.; Sinclair, L. R.


    Potential use of reservoirs and flooded fields stocked with aquatic plants for reduction of the nutrient levels of organic soil drainage water was evaluated. The treatment systems include 1) a large single reservoir (R1) stocked with waterhyacinth ( Eichhornia crassipes), elodea ( Egeria densa), and cattails ( Typha sp.) in series; 2) three small reservoirs in series with waterhyacinth (R2), elodea (R3), and cattails (R4), grown in independent reservoirs; 3) a control reservoir (R5) with no cultivated plants; 4) a large single flooded field planted to cattails; 5) three small flooded fields in a series planted to cattails; and 6) a flooded field with no cultivated plants. Drainage water was pumped daily (6 hours a day, and 6 days a week) into these systems for a period of 27 months at predetermined constant flow rates. Water samples were collected at the inlet and outlet of each treatment system and analyzed for N and P forms. The series of reservoirs stocked with aquatic plants functioned effectively in the removal of N and P from agricultural drainage water, compared to a single large reservoir. Allowing the water to flow through the reservoir stocked with waterhyacinth plants with a residence time of 3.6 days was adequate to remove about 50% of the incoming inorganic N. Allowing the water to flow through a series of two small reservoirs, R2 and R3, with a residence time of 7.3 days was necessary to remove about 60% of the incoming ortho-P. Flooded fields were effective in the removal of inorganic N, but showed poor efficiency in the removal of ortho-P.

  12. Investigating the Efficiency of Biological Filters for Ammonia Removal

    Directory of Open Access Journals (Sweden)

    S Motesaddi Zarandi, MR Massoudinejad, A Mazaheri Tehrani, H Pouri


    Full Text Available Backgrounds and Aims: Ammonia removal from air to prevent severe damage to the environment and living organisms is very important. Biofiltration is an efficient, easy, cost-effective, and environmentally friendly process for degradation of ammonia from waste air. The aim of this study is to investigate the efficiency of biological filtration using a compost and scallop bed for ammonia removal. Materials and Methods: According to the ammonia removal method a column with 14cm inner diameter and 45cm height made from transparent Plexiglas was used. The column was filled up to 25 cm with compost and scallop (with a scallop: compost ratio of 1:4. In this study, performance of the biofilter was studied under 10 different flow rates (1, 2, 3, 4, 5, 6, 7, 8, 9 and 10 lit/min and 5 different concentrations (0-20, 20-40, 40-60, 60-80 and 80-100 ppm at a temperature of 25 degrees Celsius. Results: The results of this study showed that efficiency is decreased when the flow rate or concentration is increased because the microbial population is reduced. The efficiency was reduced by 84.6-98.2 percent. Maximum efficiency occurred at a 0.19g/(m3.h loading rate. Efficiency was in 0-20 concentration intervals at a flow rate of 1 lit/min and at an Empty Bed Residence Time (EBRT of 240 seconds. Conclusion: The results show that a biofilter with a compost and scallop bed is efficient for ammonia removal from air. Results can be optimized in the design and operation of biological systems to be used in the industrial control of ammonia gas.


    NARCIS (Netherlands)



    Recent research on the process of biological phosphorus removal in lab-scale treatment systems has indicated that: (i) the development of an actively polyP-accumulating bacterial community after the introduction of an anaerobic period may take at least 4 months; (ii) up to 80% of all aerobic bacteri

  14. Biological removal of arsenic pollution by soil fungi. (United States)

    Srivastava, Pankaj Kumar; Vaish, Aradhana; Dwivedi, Sanjay; Chakrabarty, Debasis; Singh, Nandita; Tripathi, Rudra Deo


    Fifteen fungal strains were isolated from arsenic contaminated (range 9.45-15.63 mg kg(-1)) agricultural soils from the state of West Bengal, India. Five fungal strains were belonged to the Aspergillus and Trichoderma group each, however, remaining five were identified as the Neocosmospora, Sordaria, Rhizopus, Penicillium and sterile mycelial strain. All these fungal strains were cultivated on medium supplemented with 100, 500, 1000, 5000 and 10,000 mg l(-1) of sodium arsenate. After 30-day cultivation under laboratory conditions, radial growth of these strains was determined and compared with control. Toxicity and tolerance of these strains to arsenate were evaluated on the basis of tolerance index. Out of fifteen, only five fungal strains were found resistant and survived with tolerance index pattern as 0.956 (sterile mycelial strain)>0.311 (Rhizopus sp.)>0.306 (Neocosmospora sp.)>0.212 (Penicillium sp.)>0.189 (Aspergillus sp.) at 10,000 mg l(-1) of arsenate. The arsenic removal efficacy of ten fungal strains, tolerant to 5000 mg l(-1) arsenate, was also assayed under laboratory conditions for 21 days. All these strains were cultivated individually on mycological broth enriched with 10 mg l(-1) of arsenic. The initial and final pH of cultivating medium, fungal biomass and removal of arsenic by each fungal strain were evaluated. Fungal biomass of ten strains removed arsenic biologically from the medium which were ranged from 10.92 to 65.81% depending on fungal species. The flux of biovolatilized arsenic was determined indirectly by estimating the sum of arsenic content in fungal biomass and medium. The mean percent removal as flux of biovolatilized arsenic ranged from 3.71 to 29.86%. The most effective removal of arsenic was observed in the Trichoderma sp., sterile mycelial strain, Neocosmospora sp. and Rhizopus sp. fungal strains. These fungal strains can be effectively used for the bioremediation of arsenic-contaminated agricultural soils.

  15. Green microalga Scenedesmus acutus grown on municipal wastewater to couple nutrient removal with lipid accumulation for biodiesel production. (United States)

    Sacristán de Alva, Manuel; Luna-Pabello, Víctor M; Cadena, Erasmo; Ortíz, Edgar


    The green microalga Scenedesmus acutus was cultivated in two different municipal wastewater discharges (pre- and post-treated), and was compared to a culture medium with basic nutrients (20% of N, P, K), in order to study the simultaneous potential of nutrient removal and lipid accumulation ability. The highest level of nutrient removal was found in the pretreated wastewater discharge (achieving a high removal of phosphorus [66%] and organic nitrogen [94%]). Likewise, better results on biomass productivity and lipid accumulation were found in cultures using pretreated wastewater compared to enriched medium, obtaining 79.9 mg/L, and 280 mg/L, respectively. Since the best results were found in pretreated wastewater, the biodiesel preparation was performed using said medium at small-scale. After cultivation, 249.4 mg/L of biodiesel were obtained. According to this analysis, S. acutus could be used for wastewater treatment producing biomass with a suitable content of lipids, convenient for biodiesel production.

  16. Enhanced biological phosphorus removal with different carbon sources. (United States)

    Shen, Nan; Zhou, Yan


    Enhanced biological phosphorus removal (EBPR) process is one of the most economical and sustainable methods for phosphorus removal from wastewater. However, the performance of EBPR can be affected by available carbon sources types in the wastewater that may induce different functional microbial communities in the process. Glycogen accumulating organisms (GAOs) and polyphosphate accumulating organisms (PAOs) are commonly found by coexisting in the EBPR process. Predominance of GAO population may lead to EBPR failure due to the competition on carbon source with PAO without contributing phosphorus removal. Carbon sources indeed play an important role in alteration of PAOs and GAOs in EBPR processes. Various types of carbon sources have been investigated for EBPR performance. Certain carbon sources tend to enrich specific groups of GAOs and/or PAOs. This review summarizes the types of carbon sources applied in EBPR systems and highlights the roles of these carbon sources in PAO and GAO competition. Both single (e.g., acetate, propionate, glucose, ethanol, and amino acid) and complex carbon sources (e.g., yeast extract, peptone, and mixed carbon sources) are discussed in this review. Meanwhile, the environmental friendly and economical carbon sources that are derived from waste materials, such as crude glycerol and wasted sludge, are also discussed and compared.

  17. Biological removal of cationic fission products from nuclear wastewater. (United States)

    Ngwenya, N; Chirwa, E M N


    Nuclear energy is becoming a preferred energy source amidst rising concerns over the impacts of fossil fuel based energy on global warming and climate change. However, the radioactive waste generated during nuclear power generation contains harmful long-lived fission products such as strontium (Sr). In this study, cationic strontium uptake from solution by microbial cultures obtained from mine wastewater is evaluated. A high strontium removal capacity (q(max)) with maximum loading of 444 mg/g biomass was achieved by a mixed sulphate reducing bacteria (SRB) culture. Sr removal in SRB was facilitated by cell surface based electrostatic interactions with the formation of weak ionic bonds, as 68% of the adsorbed Sr(2+) was easily desorbed from the biomass in an ion exchange reaction with MgCl₂. To a lesser extent, precipitation reactions were also found to account for the removal of Sr from aqueous solution as about 3% of the sorbed Sr was precipitated due to the presence of chemical ligands while the remainder occurred as an immobile fraction. Further analysis of the Sr-loaded SRB biomass by scanning electron microscopy (SEM) coupled to energy dispersive X-ray (EDX) confirmed extracellular Sr(2+) precipitation as a result of chemical interaction. In summary, the obtained results demonstrate the prospects of using biological technologies for the remediation of industrial wastewaters contaminated by fission products.

  18. Biological nitrate removal using a food waste-derived carbon source in synthetic wastewater and real sewage. (United States)

    Zhang, Haowei; Jiang, Jianguo; Li, Menglu; Yan, Feng; Gong, Changxiu; Wang, Quan


    The production of volatile fatty acids (VFAs) from food waste to improve biological nutrient removal has drawn much attention. In this study, acidogenic liquid from food waste was used as an alternative carbon source for synthetic wastewater treatment. C/N ratios of 5 and 6 were suitable for denitrification, and the change in acidogenic liquid composition had no negative effect on denitrification. The denitrification rates using optimal carbon-to-nitrate ratios of acidogenic liquid were more than 25 mg NO3-N/(gVSS·h). At the same time, acidogenic liquid was used to improve nutrient removal from summer and winter sewage. C/N ratios of 5 and 6 were acceptable for summer sewage treatment. Total nitrogen in the final effluent was less than 7 mg/L. Two additional hours were required for winter sewage treatment, and the C/N ratio had to be >6.

  19. Transport of biologically important nutrients by wind in an eroding cold desert (United States)

    Sankey, Joel B.; Germino, Matthew J.; Benner, Shawn G.; Glenn, Nancy F.; Hoover, Amber N.


    Wind erosion following fire is an important landscape process that can result in the redistribution of ecologically important soil resources. In this study we evaluated the potential for a fire patch in a desert shrubland to serve as a source of biologically important nutrients to the adjacent, downwind, unburned ecosystem. We analyzed nutrient concentrations (P, K, Ca, Mg, Cu, Fe, Mn, Al) in wind-transported sediments, and soils from burned and adjacent unburned surfaces, collected during the first to second growing seasons after a wildfire that burned in 2007 in Idaho, USA in sagebrush steppe; a type of cold desert shrubland. We also evaluated the timing of potential wind erosion events and weather conditions that might have contributed to nutrient availability in downwind shrubland. Findings indicated that post-fire wind erosion resulted in an important, but transient, addition of nutrients on the downwind shrubland. Aeolian sediments from the burned area were enriched relative to both the up- and down-wind soil and indicated the potential for a fertilization effect through the deposition of the nutrient-enriched sediment during the first, but not second, summer after wildfire. Weather conditions that could have produced nutrient transport events might have provided increased soil moisture necessary to make nutrients accessible for plants in the desert environment. Wind transport of nutrients following fire is likely important in the sagebrush steppe as it could contribute to pulses of resource availability that might, for example, affect plant species differently depending on their phenology, and nutrient- and water-use requirements.

  20. Nutrient removal from separated pig manure digestate liquid using hybrid biofilters. (United States)

    Zhang, Mingchuan; Lawlor, Peadar G; Hu, Zhenhu; Zhan, Xinmin


    In this study, laboratory-scale hybrid biofilters were set up to treat the separated pig manure digestate liquid at two loading rates of 0.12 and 0.07 kg N m(-3) per day. The hybrid biofilters were operated with a sequencing batch reactor mode. Over the operation of 136 days, 84% and 88% of total nitrogen was removed on average in addition with complete nitrification at the high loading rate and low loading rate, respectively. In the anoxic phase, the nitrate reduction rates were 0.31 and 0.24 mg L(-1) min(-1); and in the aerobic phase, nitrification rates were 0.29 and 0.18 mg L(-1) min(-1) at the high loading rate and low loading rate, respectively. It was found that in the hybrid biofilters, biofilm biomass had much higher nitrification and denitrification activities than suspended growth biomass. Phosphorus removals achieved were up to 88%. The results show the hybrid biofilter technology is valid for high nutrient pig manure digestate liquid treatment.

  1. A novel algal biofilm membrane photobioreactor for attached microalgae growth and nutrients removal from secondary effluent. (United States)

    Gao, Feng; Yang, Zhao-Hui; Li, Chen; Zeng, Guang-Ming; Ma, Dan-Hui; Zhou, Li


    In this study, a novel algal biofilm membrane photobioreactor (BMPBR) equipped with solid carriers and submerged membrane module was developed for attached growth of Chlorella vulgaris and secondary effluent treatment. The volumetric microalgae production achieved in BMPBR was 0.072 g L(-1) d(-1), which was 1.44-fold larger than that in suspended growth membrane photobioreactor (MPBR). Furthermore, 72.4% of the total produced algal biomass was immobilized as algal biofilm in BMPBR. Advanced nutrients removal from secondary effluent was achieved both in BMPBR and MPBR, with average reduction of about 85% for PO4(3-)-P in the stable stage. Additionally, BMPBR showed better nitrogen removal performance than MPBR due to its higher algal biomass productivity. Moreover, with the filtration effect of the submerged membrane module in the reactor, suspended microalgae could be completely isolated from the effluent and a low average SS concentration of 0.28 mg L(-1) was achieved in the effluent of BMPBR.

  2. Identification and characterization of a freshwater microalga Scenedesmus SDEC-8 for nutrient removal and biodiesel production. (United States)

    Song, Mingming; Pei, Haiyan; Hu, Wenrong; Zhang, Shuo; Ma, Guixia; Han, Lin; Ji, Yan


    The selection of the right strains is of fundamental important to the success of the algae-based oil industry. From the six newly isolated microalgae strains tested for growth, fatty acid methyl ester (FAME) profiles and biodiesel properties, Scenedesmus SDEC-8, with favorable C16:0 fatty acids (73.43%), showed the best combined results. Then, morphological and molecular identification were examined. From the three wastewaters samples, Scenedesmus SDEC-8 showed good ability to yield oil and remove nutrients, which were comparable with other reports. In b artificial wastewater (TN 40 mg L(-1), TP 8 mg L(-1)), Scenedesmus SDEC-8 achieved the highest value of lipid productivity (53.84 mg L(-1) d(-1)), MUFA content (35.35%) and total FAME content (59.57±0.02 mg g(-1) DW), besides higher removal efficiencies of TN (99.18%) and TP (98.86%) helped effluent directly discharge and smaller dilution factor of N, P (3.3 and 9) which was good for lessening water utilization.

  3. Modelling biological and chemically induced precipitation of calcium phosphate in enhanced biological phosphorus removal systems. (United States)

    Barat, R; Montoya, T; Seco, A; Ferrer, J


    The biologically induced precipitation processes can be important in wastewater treatment, in particular treating raw wastewater with high calcium concentration combined with Enhanced Biological Phosphorus Removal. Currently, there is little information and experience in modelling jointly biological and chemical processes. This paper presents a calcium phosphate precipitation model and its inclusion in the Activated Sludge Model No 2d (ASM2d). The proposed precipitation model considers that aqueous phase reactions quickly achieve the chemical equilibrium and that aqueous-solid change is kinetically governed. The model was calibrated using data from four experiments in a Sequencing Batch Reactor (SBR) operated for EBPR and finally validated with two experiments. The precipitation model proposed was able to reproduce the dynamics of amorphous calcium phosphate (ACP) formation and later crystallization to hydroxyapatite (HAP) under different scenarios. The model successfully characterised the EBPR performance of the SBR, including the biological, physical and chemical processes.

  4. Fed-batch cultivation of Arthrospira and Chlorella in ammonia-rich wastewater: Optimization of nutrient removal and biomass production. (United States)

    Markou, Giorgos


    In the present work the cyanobacterium Arthrospira platensis and the microalga Chlorella vulgaris were fed-batch cultivated in ammonia-rich wastewater derived from the anaerobic digestion of poultry litter. Aim of the study was to maximize the biomass production along with the nutrient removal aiming to wastewater treatment. Ammonia and phosphorus removals were very high (>95%) for all cultures investigated. Both microorganisms were able to remove volatile fatty acids to an extent of >90%, indicating that they were capable of mixotrophic growth. Chemical oxygen demand and proteins were also removed in various degrees. In contrast, in all cultures carbohydrate concentration was increased. The biochemical composition of the microorganisms varied greatly and was influenced by the indicate that the nutrient availability. A. platensis accumulated carbohydrates (≈ 40%), while C. vulgaris accumulated lipids (≈ 50%), rendering them interesting for biofuel production.

  5. Aerobic granules formation and nutrients removal characteristics in sequencing batch airlift reactor (SBAR) at low temperature. (United States)

    Bao, Ruiling; Yu, Shuili; Shi, Wenxin; Zhang, Xuedong; Wang, Yulan


    To understand the effect of low temperature on the formation of aerobic granules and their nutrient removal characteristics, an aerobic granular sequencing batch airlift reactor (SBAR) has been operated at 10 degrees C using a mixed carbon source of glucose and sodium acetate. The results showed that aerobic granules were obtained and that the reactor performed in stable manner under the applied conditions. The granules had a compact structure and a clear out-surface. The average parameters of the granules were: diameter 3.4mm, wet density 1.036 g mL(-1), sludge volume index 37 mL g(-1), and settling velocity 18.6-65.1 cm min(-1). Nitrite accumulation was observed, with a nitrite accumulation rate (NO(2)(-)-N/NO(x)(-)-N) between 35% and 43% at the beginning of the start-up stage. During the stable stage, NO(x) was present at a level below the detection limit. However, when the influent COD concentration was halved (resulting in COD/N a reduction of the COD/N from 20:1 to 10:1) nitrite accumulation was observed once more with an effluent nitrite accumulation rate of 94.8%. Phosphorus release was observed in the static feeding phase and also during the initial 20-30 min of the aerobic phase. Neither the low temperature nor adjustment of the COD/P ratio from 100:1 to 25:1 had any influence on the phosphorus removal efficiency under the operating conditions. In the granular reactor with the influent load rates for COD, NH(4)(+)-N, and PO(4)(3-)-P of 1.2-2.4, 0.112 and 0.012-0.024 kg m(-3)d(-1), the respective removal efficiencies at low temperature were 90.6-95.4%, 72.8-82.1% and 95.8-97.9%.

  6. Population dynamics of bacteria involved in enhanced biological phosphorus removal in Danish wastewater treatment plants. (United States)

    Mielczarek, Artur Tomasz; Nguyen, Hien Thi Thu; Nielsen, Jeppe Lund; Nielsen, Per Halkjær


    The enhanced biological phosphorus removal (EBPR) process is increasingly popular as a sustainable method for removal of phosphorus (P) from wastewater. This study consisted of a comprehensive three-year investigation of the identity and population dynamics of polyphosphate-accumulating organisms (PAOs) and glycogen-accumulating organisms (GAOs) in 28 Danish municipal wastewater treatment plants with nutrient removal. Fluorescence in situ hybridization was applied to quantify ten probe-defined populations of PAO and GAO that in total constituted a large fraction (30% on average) of the entire microbial community targeted by the EUBmix probes. Two PAO genera, Accumulibacter and Tetrasphaera, were very abundant in all EBPR plants (average of 3.7% and 27% of all bacteria, respectively), and their abundance was relatively stable in the Danish full-scale plants without clear temporal variations. GAOs were occasionally present in some plants (Competibacter in 11 plants, Defluviicoccus in 6 plants) and were consistent in only a few plants. This shows that these were not core species in the EBPR communities. The total GAO abundance was always lower than that of Accumulibacter. In plants without EBPR design, the abundance of PAO and GAO was significantly lower. Competibacter correlated in general with high fraction of industrial wastewater. In specific plants Accumulibacter correlated with high C/P ratio of the wastewater and Tetrasphaera with high organic loading. Interestingly, the relative microbial composition of the PAO/GAO species was unique to each plant over time, which gives a characteristic plant-specific "fingerprint".

  7. Stabilisation of Biological Phosphorus Removal from Municipal Wastewater

    DEFF Research Database (Denmark)

    Krühne, Ulrich

    The biological phosphorus removal (BPR) from wastewater has developed considerably during the last decades and is applied in many present wastewater treatment plants (WWTP) all over the world. The process performance and the control of the BPR are under the influences of daily and seasonal...... variations of the influent wastewater concentrations and are not yet always guaranteed. Even though the scientific knowledge and practical experience has reached a high level of understanding of the involved key-processes it is still necessary to apply chemical precipitation of phosphorus during the time...... have been performed on an alternating pilot plant, receiving municipal wastewater. The pilot plant is equipped with an automatic measurement system based on the flow injection analysis (FIA) principle. Continuos analysis of the ammonium (NH4-N), nitrate (as NOx-N) and phosphorus (PO4-P) was performed...

  8. Optimization of biological sulfide removal in a CSTR bioreactor. (United States)

    Roosta, Aliakbar; Jahanmiri, Abdolhossein; Mowla, Dariush; Niazi, Ali; Sotoodeh, Hamidreza


    In this study, biological sulfide removal from natural gas in a continuous bioreactor is investigated for estimation of the optimal operational parameters. According to the carried out reactions, sulfide can be converted to elemental sulfur, sulfate, thiosulfate, and polysulfide, of which elemental sulfur is the desired product. A mathematical model is developed and was used for investigation of the effect of various parameters on elemental sulfur selectivity. The results of the simulation show that elemental sulfur selectivity is a function of dissolved oxygen, sulfide load, pH, and concentration of bacteria. Optimal parameter values are calculated for maximum elemental sulfur selectivity by using genetic algorithm as an adaptive heuristic search. In the optimal conditions, 87.76% of sulfide loaded to the bioreactor is converted to elemental sulfur.

  9. Evaluation of cyanobacteria: Spirulina maxima for growth, nutrient removal, and quality on waste-effluent media in batch cultures

    Energy Technology Data Exchange (ETDEWEB)

    Tadros, M.G.; Phillips, J. (Alabama A M Univ., Normal (United States))


    Spirulina maxima, a semi-microscopic filamentous blue-green alga, was inoculated in synthetic and waste media of different sources. The alga was evaluated for growth yield, uptake of nutrients and chemical composition. The removal rate of N and P was rapid during the first week of growth. At the end of the second week, more than 90% of the total -P and -N was removed. The mass of alga was high. The quality of the alga obtained in different media did not show much variations, except when the medium was limited in nutrients. Results indicated that Spirulina may be integrated into the effluent treatment system. Recycling waste materials not only minimizes the problem of water pollution but also revitalizes the inherently rich nutrients of waste. The biomass obtained from cultivation of Spirulina in these wastewater media may be used as a pigment-protein supplement in animal feed and as raw material for certain chemicals.

  10. Hierarchical eco-restoration: a systematical approach to removal of COD and dissolved nutrients from an intensive agricultural area. (United States)

    Wu, Yonghong; Hu, Zhengyi; Yang, Linzhang


    A systematical approach based on hierarchical eco-restoration system for the simultaneous removal of COD and dissolved nutrients was proposed and applied in a complex residential-cropland area in Kunming, China from August 2006 to August 2008, where the self-purifying capacity of the agricultural ecosystem had been lost. The system includes four main parts: (1) fertilizer management and agricultural structure optimization, (2) nutrients reuse, (3) wastewater treatment, and (4) catchment restoration. The results showed that the average removal efficiencies were 90% for COD, 93% for ammonia, 94% for nitrate and 71% for total dissolved phosphorus (TDP) when the hierarchical eco-restoration agricultural system was in a relatively steady-state condition. The emergence of 14 species of macrophytes and 4 species of zoobenthos indicated that the growth conditions for the plankton were improved. The results demonstrated that this promising and environmentally benign hierarchical eco-restoration system could decrease the output of nutrients and reduce downstream eutrophication risk.

  11. Methanethiol Removal from Biogas by Biological Conversion in an Anaerobic Biotrickling Filter

    Institute of Scientific and Technical Information of China (English)

    王佳佳; 张卫江; 徐姣


    In this study, methanethiol(MT)-degradation bacteria were cultivated by using MT, methanol and trimethylamine as carbon sources under anaerobic conditions. It was found that the batch bacteria used MT and metha-nol as carbon sources grew faster than those used trimethylamine. The enriched bacteria used MT and methanol as the carbon sources were respectively inoculated in different biotrickling filters. The biological conversion performance of MT under anaerobic conditions was investigated in biotrickling filters. The results showed that the performance of the biotrickling filter inoculated with the bacteria enriched using MT was better than that inoculated with the bacteria en-riched using methanol. When the inlet concentration of MT was 0.005vol%(50,ppm), the empty bed residence time was 50 s, pH value was 8.0, and the flow rate of the nutrient solution was 10 L/h, the removal efficiency of MT reached 95.3%. Adding methanol stimulated the growth of the biomass and the degradation of MT, but caused that some bacteria only degrading methanol outcompeted the bacteria only degrading MT. The concentration of sodium bicarbonate in the nutrient solution needed to be controlled lower than 30 g/L, otherwise, it would be harmful to the degradation of MT.

  12. A multiscale analysis of nutrient transport and biological tissue growth in vitro

    KAUST Repository

    O'Dea, R. D.


    © The authors 2014. In this paper, we consider the derivation of macroscopic equations appropriate to describe the growth of biological tissue, employing a multiple-scale homogenization method to accommodate explicitly the influence of the underlying microscale structure of the material, and its evolution, on the macroscale dynamics. Such methods have been widely used to study porous and poroelastic materials; however, a distinguishing feature of biological tissue is its ability to remodel continuously in response to local environmental cues. Here, we present the derivation of a model broadly applicable to tissue engineering applications, characterized by cell proliferation and extracellular matrix deposition in porous scaffolds used within tissue culture systems, which we use to study coupling between fluid flow, nutrient transport, and microscale tissue growth. Attention is restricted to surface accretion within a rigid porous medium saturated with a Newtonian fluid; coupling between the various dynamics is achieved by specifying the rate of microscale growth to be dependent upon the uptake of a generic diffusible nutrient. The resulting macroscale model comprises a Darcy-type equation governing fluid flow, with flow characteristics dictated by the assumed periodic microstructure and surface growth rate of the porous medium, coupled to an advection-reaction equation specifying the nutrient concentration. Illustrative numerical simulations are presented to indicate the influence of microscale growth on macroscale dynamics, and to highlight the importance of including experimentally relevant microstructural information to correctly determine flow dynamics and nutrient delivery in tissue engineering applications.

  13. Efficacy of Chlorella pyrenoidosa and Scenedesmus abundans for Nutrient Removal in Rice Mill Effluent (Paddy Soaked Water). (United States)

    Abinandan, S; Bhattacharya, Ribhu; Shanthakumar, S


    Microalgae are product of sustainable development owing to its ability to treat variety of wastewater effluents and thus produced biomass can serve as value added product for various commercial applications. This paper deals with the cultivation of microalgae species namely Chlorella pyrenoidosa and Scenedesmus abundans in rice mill effluent (i.e., paddy soaked water) for nutrient removal. In order to investigate the nutrient removal capability, microalgae are subjected to cultivation in both raw and autoclaved samples. The maximum phosphate removal by Scenedesmus abundans and Chlorella pyrenoidosa in raw sample was 98.3% and 97.6%, respectively, whereas, the removal of ammoniacal nitrogen by Scenedesmus abundans and Chlorella pyrenoidosa in raw sample was 92% and 90.3%, respectively. The growth (measured in terms of chlorophyll content) of Scenedesmus abundans and Chlorella pyrenoidosa in raw sample was 3.88 mg/l and 5.55 mg/l, respectively. The results indicate the suitability of microalgae cultivation in rice mill effluent treatment for nutrient removal.

  14. Influence of carbon sources on nutrient removal in A(2)/O-MBRs: Availability assessment of internal carbon source. (United States)

    Xu, Rongle; Fan, Yaobo; Wei, Yuansong; Wang, Yawei; Luo, Nan; Yang, Min; Yuan, Xing; Yu, Rong


    Both internal carbon source and some external carbon sources were used to improve the nutrient removal in Anaerobic-Anoxic-Oxic-Membrane Bioreactor (A(2)/O-MBRs), and their technical and cost analysis was investigated. The experimental results showed that the nutrient removals were improved by all the carbon source additions. The total nitrogen and phosphorus removal efficiency were higher in the experiments with external carbon source additions than that with internal carbon source addition. It was found that pathways of nitrogen and phosphorus transform were different dependent on different carbon source additions by the mass balance analysis. With external carbon source addition, the simultaneous nitrification and denitrification occurred in aerobic zone, and the P-uptake in aerobic phase was evident. Therefore, with addition of C-MHP (internal carbon source produced from sludge pretreatment by microwave-H2O2 process), the denitrification and phosphorus-uptake in anoxic zone was notable. Cost analysis showed that the unit nitrogen removal costs were 57.13CNY/kg N of C-acetate addition and 54.48CNY/kgN of C-MHP addition, respectively. The results indicated that the C-MHP has a good technical and economic feasibility to substitute external carbon sources partially for nutrient removal.

  15. Nutrient removal capacity of wood residues for the Agro-environmental safety of ground and surface waters

    Directory of Open Access Journals (Sweden)

    Paulo A. Dumont


    Full Text Available The aim of this study was to determine the effectiveness of wood residues in the removal of nutrients (ammonium-N; NH4-N from nutrient-rich (NH4-N waters. The water holding capacity of the wood materials was also determined. Carried out at Rothamsted Research, North Wyke, UK, this controlled laboratory experiment tested two wood residues; in length, one being 1-2cm and the other from 150 µm (microns to 9.5mm. Although a wide range of studies have shown the effectiveness and performance of various absorbent materials as animal beddings, such as straw (cereal straw, woodchip (sawdust, bark or wood shavings, bracken and rushes, only few have focused on the NH4-N sorption/desorption capacity. The depuration capacity of wood residues from nutrient-rich effluents such as those from cattle bedded on woodchip or straw will be controlled by processes such as sorption (adsorption-absorption and desorption of nutrients. Studies have reported the nitrogen removal capacity of woodchip materials and biochar from woodchip as well as removal of NH4+-N from domestic and municipal wastewater, farm dirty water, landfill and industry effluents. These studies have observed that the mechanism of removal of nitrogen is by either increasing NO3--N removal form leachate by enhancing N2O losses via denitrification (biochar as carbon source for denitrifiers or by decreasing NH4+-N in leachate through adsorption to negatively charged sites. Results showed that although the cation exchange capacity (CEC and surface area (SA are both fundamental properties of adsorbent materials, no correlation was found with CEC and adsorption or desorption. Nor did changes in pH appear to be sufficiently important to cause changes in CEC. For this reason, osmotic pressure appeared to be a more predominant parameter controlling processes of adsorption and desorption of NH4+-N in both wood residues. Thus, wood residues high in NH4+-N should be avoided, as they could have an opposite effect

  16. Improved nutrient removal using in situ continuous on-line sensors with short response time. (United States)

    Ingildsen, P; Wendelboe, H


    Nutrient sensors that can be located directly in the activated sludge processes are gaining in number at wastewater treatment plants. The in situ location of the sensors means that they can be located close to the processes that they aim to control and hence are perfectly suited for automatic process control. Compared to the location of automatic analysers in the effluent from the sedimentation reactors the in situ location means a large reduction in the response time. The settlers typically work as a first-order delay on the signal with a retention time in the range of 4-12 hours depending on the size of the settlers. Automatic process control of the nitrogen and phosphorus removal processes means that considerable improvements in the performance of aeration, internal recirculation, carbon dosage and phosphate precipitation dosage can be reached by using a simple control structure as well as simple PID controllers. The performance improvements can be seen in decreased energy and chemicals consumption and less variation in effluent concentrations of ammonium, total nitrogen and phosphate. Simple control schemes are demonstrated for the pre-denitrification and the post precipitation system by means of full-scale plant experiments and model simulations.

  17. Grazer removal and nutrient enrichment as recovery enhancers for overexploited rocky subtidal habitats. (United States)

    Guarnieri, Giuseppe; Bevilacqua, Stanislao; Vignes, Fabio; Fraschetti, Simonetta


    Increasing anthropogenic pressures are causing long-lasting regime shifts from high-diversity ecosystems to low-diversity degraded ones. Understanding the effects of multiple threats on ecosystems, and identifying processes allowing for the recovery of biodiversity, are the current major challenges in ecology. In several temperate marine areas, large parts of rocky subtidal habitats characterised by high diversity have been completely degraded to barren grounds by overfishing, including illegal date mussel fishing. Bare areas are characterized by the dominance of sea urchins whose grazing perpetuates the impact of overfishing. We investigated experimentally the separate and combined effects of nutrient enrichment and sea urchin exclusion on the recovery of barren grounds. Our results indicate that the two factors have a synergistic effect leading to the re-establishment of erect macroalgal canopies, enhancing the structural complexity of subtidal assemblages. In particular, in the overfished system considered here, the recovery of disturbed assemblages could occur only if sea urchins are removed. However, the recolonization of barren grounds by erect macroalgae is further enhanced under enriched conditions. This study demonstrates that the recovery of dramatically depleted marine habitats is possible, and provides useful indications for specific management actions, which at present are totally lacking, to achieve the restoration of barren grounds caused by human activity.

  18. Potential of Duckweed for Swine Wastewater Nutrient removal and Biomass Valorisation through Anaerobic Co-digestion

    Directory of Open Access Journals (Sweden)

    Luis Pena


    Full Text Available Over the last decades, phytodepuration has been considered an efficient technology to treat wastewaters. The present study reports a bench scale depuration assay of swine wastewater using Lemna minor. The highest observed growth rate obtained in swine wastewater was 3.1 ± 0.3 gDW m−2 day−1 and the highest nitrogen and phosphorus uptake were 140 mg N m−2 day−1 and 3.47 mg P m−2 day−1, respectively. The chemical oxygen demand removal efficiency in the swine wastewater assay was 58.9 ± 2.0%. Furthermore, the biomass valorisation by anaerobic co-digestion with swine wastewater was assessed. Results showed a clear improvement in specific methane production rate (around 40% when compared to mono-substrate anaerobic digestion. The highest methane specific production, 131.0 ± 0.8 mL CH4 g−1 chemical oxygen demand, was obtained with a mixture containing 100 g of duckweed per liter of pre-treated swine wastewater. The water-nutrients-energy nexus approach showed to be promising for swine waste management.

  19. Comparing results of cultured and uncultured biological methods used in biological phosphorus removal

    Institute of Scientific and Technical Information of China (English)


    Increasing attention has been paid to phosphate-accumulating organisms (PAOs) for their important role in biological phosphorus removal. In this study, microbial communities of PAOs cultivated under different carbon sources (sewage, glucose, and sodium acetate) were investigated and compared through culture-dependent and culture-independent methods, respectively. The results obtained using denaturing gradient gel electrophoresis (DGGE) of polymerase chain reaction-amplified 16S rDNA fragments revealed that the diversity of bacteria in a sewage-fed reactor (1#) was much higher than in a glucose-fed one (2#) and a sodium acetate-fed one (3#); there were common PAOs in three reactors fed by different carbon sources. Five strains were separated from three systems by using a phosphate-rich medium; they were from common bacteria isolated and three isolates could not be found in DGGE profile at all. Two isolates had good phosphorus removal ability. When the microbial diversity was studied, the molecular biological method was better than the culture-dependent one. When phosphorus removal characteristics were investigated, culture-dependent approach was more effective. Thus a combination of two methods is necessary to have a comprehensive view of PAOs.

  20. Cutting of Phragmites australis as a lake restoration technique:Productivity calculation and nutrient removal in Wuliangsuhai Lake, northern China

    Institute of Scientific and Technical Information of China (English)

    Jan Felix Kbbing; Niels Thevs; Stefan Zerbe


    Reed is one of the most frequent and dominant species in wetlands all over the world, with common reed (Phragmites australis (Cav.) Trin. ex Steud.) as the most widely distributed species. In many wetlands, P. australis plays a highly ambivalent role. On the one hand, in many wetlands it purifies wastewater, provides habitat for numerous species, and is a potentially valuable raw material, while on the other hand it is an invasive species which expands aggressively, prevents fishing, blocks ditches and waterways, and builds monospecies stands. This paper uses the eutrophic reed-swamp of Wuliangsuhai Lake in Inner Mongolia, northern China, as a case to present the multiple benefits of regular reed cutting. The reed area and aboveground biomass production are calculated based on field data. Combined with data about water and reed nutrient content, the impact of reed cutting on the lake nutrient budget (N and P) is investigated. Currently, at this lake around 100,000 tons of reed are harvested in winter annually, removing 16%and 8%of the total nitrogen and phosphorus influx, respectively. Harvesting all available winter reed could increase the nutrient removal rates to 48%and 24%, respectively. We also consider the effects of summer harvesting, in which reed biomass removal could overcompensate for the nutrient influx but could potentially reduce reed regrowth.

  1. Effect of wastewater-borne bacteria on algal growth and nutrients removal in wastewater-based algae cultivation system. (United States)

    Ma, Xiaochen; Zhou, Wenguang; Fu, Zongqiang; Cheng, Yanling; Min, Min; Liu, Yuhuan; Zhang, Yunkai; Chen, Paul; Ruan, Roger


    Centrate, a type of nutrient-rich municipal wastewater was used to determine the effect of wastewater-borne bacteria on algal growth and nutrients removal efficiency in this study. The characteristics of algal and bacterial growth profiles, wastewater nutrient removal and effect of initial algal inoculums were systematically examined. The results showed that initial algal concentration had apparent effect on bacterial growth, and the presence of bacteria had a significant influence on algal growth pattern, suggesting symbiotic relationship between algae and bacteria at the initial stage of algae cultivation. The maximum algal biomass of 2.01 g/L with 0.1g/L initial algal inoculums concentration can be obtained during algae cultivation in raw centrate medium. The synergistic effect of centrate-borne bacteria and microalgae on algae growth and nutrient removal performance at initial fast growth stage has great potential to be applied to pilot-scale wastewater-based algae wastewater system cultivated in continuous or semi-continuous mode.

  2. Past, present and future of technologies for nutrient removal in WWTP; Pasado, presente y futuro de tecnologias para la eliminacion de nutrientes en EDAR

    Energy Technology Data Exchange (ETDEWEB)

    Larrea Urcola, L.


    In the past decades, nitrogen and phosphorous (nutrient) removal from urban wastewater has been carried out throughout the world mainly using different reactor configurations of activated sludge processes like A{sup 2} O, UCT, etc. Since 2000, three innovative technologies that mitigate activated sludge processes limitations have been introduced in new and existing plants as they operate with high biomass concentration and without filamentous bulking. One technology is the membrane bioreactor where similar configurations to activated slugged processes are applied, but the secondary settler is replaced by a membrane tank. The two other technologies are based on biofilm processes: One is the submerged granular bio filter where a fixed bed of small supports of 3-8 mm causes biodegradation and filtration phenomena, thus not requiring a secondary settler. The second one is the IFAS hybrid process where moving plastic supports promotes nitrification in the biofilm, while denitrification and phosphorous removal take place in suspension. In order to meet stricter effluent nitrogen requirements, currently nitrogen removal from the water in the sludge line that returns to the head of the plant, is proposed. Innovative technologies are based on partial nitrification and anammox, using biomass in suspension, in biofilm and in granules. With a horizon application in the medium term, emergent technologies are being developed, like granular processes, combination of membrane and biofilm systems and the recovery of nutrients in the context of the WWTP as a facility of resources. (Author)

  3. From Earth to Space: Application of Biological Treatment for the Removal of Ammonia from Water (United States)

    Pickering, Karen; Adam, Niklas; White, Dawn; Ghosh, Amlan; Seidel, Chad


    Managing ammonia is often a challenge in both drinking water and wastewater treatment facilities. Ammonia is unregulated in drinking water, but its presence may result in numerous water quality issues in the distribution system such as loss of residual disinfectant, nitrification, and corrosion. Ammonia concentrations need to be managed in wastewater effluent to sustain the health of receiving water bodies. Biological treatment involves the microbiological oxidation of ammonia to nitrate through a two-step process. While nitrification is common in the environment, and nitrifying bacteria can grow rapidly on filtration media, appropriate conditions, such as the presence of dissolved oxygen and required nutrients, need to be established. This presentation will highlight results from two ongoing research programs - one at NASA's Johnson Space Center, and the other at a drinking water facility in California. Both programs are designed to demonstrate nitrification through biological treatment. The objective of NASA's research is to be able to recycle wastewater to potable water for spaceflight missions. To this end, a biological water processor (BWP) has been integrated with a forward osmosis secondary treatment system (FOST). Bacteria mineralize organic carbon to carbon dioxide as well as ammonia-nitrogen present in the wastewater to nitrogen gas, through a combination of nitrification and denitrification. The effluent from the BWP system is low in organic contaminants, but high in total dissolved solids. The FOST system, integrated downstream of the BWP, removes dissolved solids through a combination of concentration-driven forward osmosis and pressure driven reverse osmosis. The integrated system testing planned for this year is expected to produce water that requires only a polishing step to meet potable water requirements for spaceflight. The pilot study in California is being conducted on Golden State Water Company's Yukon wells that have hydrogen sulfide odor

  4. Factors affecting population of filamentous bacteria in wastewater treatment plants with nutrients removal. (United States)

    Miłobędzka, Aleksandra; Witeska, Anna; Muszyński, Adam


    Filamentous population in activated sludge and key operational parameters of full-scale municipal wastewater treatment plants (WWTPs) with bulking problems representative for Poland were investigated with quantitative fluorescence in situ hybridization. Statistical analyses revealed few relationships between operational parameters and biovolume of filamentous bacteria. Sludge age was not only positively correlated with abundance of Chloroflexi (parametric correlation and principal component analysis (PCA)), but also differentiated Microthrix population (analysis of variance (ANOVA)). Phylum Chloroflexi and pH presented a negative relation during the study (PCA). ANOVA showed that pH of influent and sludge volume index (SVI) differentiated abundance of types 0803 and 1851 of Chloroflexi and candidate division TM7. SVI increased along with higher abundance of Microthrix (positive parametric and non-parametric correlations and positive relation in PCA). Biovolumes of morphotypes 0803 and 1851 of Chloroflexi were differentiated by organic matter in influent, also by nutrients in the case of Chloroflexi type 1851. Chemical and biological oxygen demands (COD and BOD5, respectively) were negatively correlated with Microthrix. COD also differentiated the abundance of Haliscomenobacter hydrossis. Results of the study can be used to prevent WWTPs from excessive proliferation of filamentous bacteria and operational problems caused by them--bulking and foaming of activated sludge.

  5. Removal of Pesticides and Inorganic Contaminants in Anaerobic and Aerobic Biological Contactors (United States)

    This presentation contains data on the removal of pesticides (acetochlor, clethodim, dicrotophos), ammonia, nitrate, bromate and perchlorate through aerobic and anaerobic biological treatment processes.

  6. Removal of chemical oxygen demand and dissolved nutrients by a sunken lawn infiltration system during intermittent storm events. (United States)

    Hou, Lizhu; Yang, Huan; Li, Ming


    Urban surface water runoff typically contains high but varying amounts of organic matter and nutrients that require removal before reuse. Infiltration systems such as sunken lawns can improve water quality. However, there is currently insufficient information describing the treatment efficiency of lawn-based infiltration systems. In this study, novel sunken lawn infiltration systems (SLISs) were designed and their pollutant removal effectiveness was assessed. The results revealed that SLISs with Poa pratensis and Lolium perenne effectively removed most chemical oxygen demand (CODCr) and dissolved nutrients. Average CODCr, total nitrogen (TN), ammonium-nitrogen (NH4(+)-N) and total phosphorus (TP) concentrations were reduced by 78.93, 66.64, 71.86 and 75.83%, respectively, and the corresponding effluent concentrations met the standard for urban miscellaneous water consumption in China. The NH4(+)-N in the synthetic runoff was shown to be removed by adsorption during the stormwater dosing and nitrification during subsequent dry days, as well as through uptake by plants. Phosphorus was mainly removed by adsorption and chemical precipitation. The NH4(+)-N and phosphorus Langmuir isotherm model fitted the clay loam soil adsorption process better than the Freundlich model. Overall, these results indicate that an SLIS provides an alternative means of removing runoff pollutants owing to its efficiency, easy operation and maintenance.

  7. Heterogeneity of intracellular polymer storage states in enhanced biological phosphorus removal (EBPR)--observation and modeling. (United States)

    Bucci, Vanni; Majed, Nehreen; Hellweger, Ferdi L; Gu, April Z


    A number of agent-based models (ABMs) for biological wastewater treatment processes have been developed, but their skill in predicting heterogeneity of intracellular storage states has not been tested against observations due to the lack of analytical methods for measuring single-cell intracellular properties. Further, several mechanisms can produce and maintain heterogeneity (e.g., different histories, uneven division) and their relative importance has not been explored. This article presents an ABM for the enhanced biological phosphorus removal (EBPR) treatment process that resolves heterogeneity in three intracellular polymer storage compounds (i.e., polyphosphate, polyhydroxybutyrate, and glycogen) in three functional microbial populations (i.e., polyphosphate-accumulating, glycogen-accumulating, and ordinary heterotrophic organisms). Model predicted distributions were compared to those based on single-cell estimates obtained using a Raman microscopy method for a laboratory-scale sequencing batch reactor (SBR) system. The model can reproduce many features of the observed heterogeneity. Two methods for introducing heterogeneity were evaluated. First, biological variability in individual cell behavior was simulated by randomizing model parameters (e.g., maximum acetate uptake rate) at division. This method produced the best fit to the data. An optimization algorithm was used to determine the best variability (i.e., coefficient of variance) for each parameter, which suggests large variability in acetate uptake. Second, biological variability in individual cell states was simulated by randomizing state variables (e.g., internal nutrient) at division, which was not able to maintain heterogeneity because the memory in the internal states is too short. These results demonstrate the ability of ABM to predict heterogeneity and provide insights into the factors that contribute to it. Comparison of the ABM with an equivalent population-level model illustrates the effect

  8. Carbon dioxide capture and nutrients removal utilizing treated sewage by concentrated microalgae cultivation in a membrane photobioreactor. (United States)

    Honda, Ryo; Boonnorat, Jarungwit; Chiemchaisri, Chart; Chiemchaisri, Wilai; Yamamoto, Kazuo


    A highly efficient microalgae cultivation process was developed for carbon dioxide capture using nutrients from treated sewage. A submerged-membrane filtration system was installed in a photobioreactor to achieve high nutrient loading and to maintain a high concentration and production of microalgae. Chlorella vulgaris, Botryococcus braunii and Spirulina platensis were continuously cultivated with simulated treated sewage and 1%-CO(2) gas. The optimum hydraulic retention time (HRT) and solids retention time (SRT) were explored to achieve the maximum CO(2) capture rate, nutrient removal rate and microalgae biomass productivity. The carbon dioxide capture rate and volumetric microalgae productivity were high when the reactor was operated under 1-day (HRT) and 18-days (SRT) conditions. The independent control of HRT and SRT is effective for efficient microalgae cultivation and carbon dioxide capture using treated sewage.

  9. Biological and chemical removal of Cr(VI) from waste water: cost and benefit analysis. (United States)

    Demir, Aynur; Arisoy, Münevver


    The objective of the present study is cost and benefit analysis of biological and chemical removal of hexavalent chromium [Cr(VI)] ions. Cost and benefit analysis were done with refer to two separate studies on removal of Cr(VI), one of heavy metals with a crucial role concerning increase in environmental pollution and disturbance of ecological balance, through biological adsorption and chemical ion-exchange. Methods of biological and chemical removal were compared with regard to their cost and percentage in chrome removal. According to the result of the comparison, cost per unit in chemical removal was calculated 0.24 euros and the ratio of chrome removal was 99.68%, whereas those of biological removal were 0.14 and 59.3% euros. Therefore, it was seen that cost per unit in chemical removal and chrome removal ratio were higher than those of biological removal method. In the current study where chrome removal is seen as immeasurable benefit in terms of human health and the environment, percentages of chrome removal were taken as measurable benefit and cost per unit of the chemicals as measurable cost.

  10. Nutrient removal efficiency and physiological responses of Desmodesmus communis at different HRTs and nutrient stress condition using different sources of urban wastewater effluents. (United States)

    Samorì, Giulia; Samorì, Chiara; Pistocchi, Rossella


    The objective of the present study was to evaluate the nutrient removal efficiency and the physiological responses in terms of growth, biochemical composition and photosynthetic activity of the autochthonous freshwater algal strain Desmodesmus communis. Microalgae were grown in a primary municipal effluent under different hydraulic retention times (HRTs) and in a two-phases process using both primary and secondary wastewater effluents. Semi-continuous cultures were operated for 7 day at 5-, 3- and 1.5-day HRT and the different dilution rate showed a greater influence on the biomass composition and nutrient removal efficiency. Removal of N-NH3 and P-PO4 was over 99 % and the highest accumulation of polysaccharides (57.2 wt.%) was obtained at high HRT (5 day); the maximum content of proteins (26.9 wt.%) was achieved at 1.5-day HRT, even if, under this condition, a clear inefficiency in terms of ammonia removal was observed. Moreover the accumulation of N-NH3 occurring at 1.5-day HRT caused the decrease of the photosynthetic response in terms of efficiency of light capture (α) and relative electron transport rate (rETR), both parameters extracted from the rapid light curves (RLC) measurements. No significant differences were observed for the total fatty acids (TFAs), with a content of 2-3.5 wt.% for each HRT condition. On the other hand, in the two-phases process, when a nutrient deprivation condition was induced by diluting the culture with the secondary wastewater effluent, the algal cells accumulated TFAs, achieving a maximum content of 9.7 wt.% and a great increment in terms of biomass (1.64 ± 0.02 g L(-1)) due to the ability of this algal strain to accumulate intracellular N. The wide and accurate investigation of the different aspects related to the whole process represents a relevant point of novelty in this research field and suggests the operational conditions for the start-up of an open pond system for wastewater treatment and biomass

  11. [Effects of COD/TN and HRT(s) on nutrients removal by an alternating anoxic/oxic CAST]. (United States)

    Wang, Li; Peng, Yong-Zhen; Ma, Juan; Liu, Yang; Ma, Ning-Ping


    The effects of different COD/TN and HRT(s) (hydraulic retention time of select) on nutrients removal were investigated by using an alternating anoxic/oxic CAST (cyclic activated sludge technology) fed with municipal wastewater. The results showed that various COD/TN and HRT(s) had a bigger influence on the nitrogen removal efficiency rather than the COD removal efficiency. As the influent C/N ratios were about 2.6 and 3.5, ammonia was removed by 98% and TN removal efficiency was increased from 62.9% to 76.2% and 72.1% to 84.6%, respectively, by increasing the HRT(s) from 1.8 h to 5 h. When the COD/TN ratio was increased to about 4.4, TN removal efficiency was decreased from 86.3% to 58.2% by enlarging the HRT(s), which was due to the incomplete nitrification of ammonia. It was also observed that both of increasing the COD/TN and HRT(s) could improve the phosphorus removal performance of the system. Furthermore, effluent of CAST reached the demanded A of integrated wastewater discharge standards (GB 18918-2002) when the COD/TN and HRT(s) were 4.4 and 1.8 h, respectively.

  12. How the novel integration of electrolysis in tidal flow constructed wetlands intensifies nutrient removal and odor control. (United States)

    Ju, Xinxin; Wu, Shubiao; Huang, Xu; Zhang, Yansheng; Dong, Renjie


    Intensified nutrient removal and odor control in a novel electrolysis-integrated tidal flow constructed wetland were evaluated. The average removal efficiencies of COD and NH4(+)-N were above 85% and 80% in the two experimental wetlands at influent COD concentration of 300 mg/L and ammonium nitrogen concentration of 60 mg/L regardless of electrolysis integration. Effluent nitrate concentration decreased from 2.5mg/L to 0.5mg/L with the reduction in current intensity from 1.5 mA/cm(2) to 0.57 mA/cm(2). This result reveals the important role of current intensity in nitrogen transformation. Owing to the ferrous and ferric iron coagulant formed through the electro-dissolution of the iron anode, electrolysis integration not only exerted a positive effect on phosphorus removal but also effectively inhibited sulfide accumulation for odor control. Although electrolysis operation enhanced nutrient removal and promoted the emission of CH4, no significant difference was observed in the microbial communities and abundance of the two experimental wetlands.

  13. Cultivation of Chlorella vulgaris JSC-6 with swine wastewater for simultaneous nutrient/COD removal and carbohydrate production. (United States)

    Wang, Yue; Guo, Wanqian; Yen, Hong-Wei; Ho, Shih-Hsin; Lo, Yung-Chung; Cheng, Chieh-Lun; Ren, Nanqi; Chang, Jo-Shu


    Swine wastewater, containing a high concentration of COD and ammonia nitrogen, is suitable for the growth of microalgae, leading to simultaneous COD/nutrients removal from the wastewater. In this study, an isolated carbohydrate-rich microalga Chlorella vulgaris JSC-6 was adopted to perform swine wastewater treatment. Nearly 60-70% COD removal and 40-90% NH3-N removal was achieved in the mixotrophic and heterotrophic culture, depending on the dilution ratio of the wastewater, while the highest removal percentage was obtained with 20-fold diluted wastewater. Mixotrophic cultivation by using fivefold diluted wastewater resulted in the highest biomass concentration of 3.96 g/L. The carbohydrate content of the microalga grown on the wastewater can reach up to 58% (per dry weight). The results indicated that the microalgae-based wastewater treatment can efficiently reduce the nutrients and COD level, and the resulting microalgal biomass had high carbohydrate content, thereby having potential applications for the fermentative production of biofuels or chemicals.

  14. Twenty years' monitoring of Mèze stabilisation ponds: part I--Removal of organic matter and nutrients. (United States)

    Picot, B; Andrianarison, T; Gosselin, J P; Brissaud, F


    The Mèze stabilisation pond system has been monitored over more than 20 years. Despite the enlargement of the plant, the organic load doubled between the early 1980s and recent years, the removal of organic matter and nutrients has been maintained at the same level for COD and increased for BOD5, N and P. Combining anaerobic, step-fed aerated and maturation ponds and multiplying the number of cells resulted in a significant improvement in the performances of the plant. Respectively 34, 24 and 23% of the applied COD was eliminated in the anaerobic, the step-fed and the first three maturation ponds, while the figures for BOD5 were 47, 26, and 19% respectively. 38% of the applied nitrogen was eliminated in the first three maturation ponds. Nitrification and denitrification seem to be a major process of nitrogen removal in warm periods. Most of the phosphorus removal was observed to take place in the two polishing ponds.

  15. Removal of nutrients and organic pollution load from pulp and paper mill effluent by microalgae in outdoor open pond. (United States)

    Usha, M T; Sarat Chandra, T; Sarada, R; Chauhan, V S


    A mixed culture of microalgae, containing two Scenedesmus species, was analysed to determine its potential in coupling of pulp and paper mill effluent treatment and microalgal cultivation. Laboratory studies suggested that 60% concentration of wastewater was optimum for microalgal cultivation. A maximum of 82% and 75% removal of BOD and COD respectively was achieved with microalgal cultivation in outdoor open pond. By the end of the cultivation period, 65% removal of NO3-N and 71.29% removal of PO4-P was observed. The fatty acid composition of mixed microalgal culture cultivated with effluent showed the palmitic acid, oleic acid, linoleic acid and α-linolenic acid as major fatty acids. The results obtained suggest that pulp and paper mill effluent could be used effectively for cultivation of microalgae to minimise the freshwater and nutrient requirements.

  16. Improving the Effectiveness of a Nutrient Removal System Composed of Microalgae and Daphnia by an Artificial Illumination

    Directory of Open Access Journals (Sweden)

    In-Ho Chang


    Full Text Available For determining the effect of illumination on nutrient removal in an artificial food web (AFW system, we launched a pilot continuous-flow system. The system consisted of a storage basin, a phytoplankton growth chamber, and a zooplankton growth chamber. A 25,000 Lux AFW-light emitting diode (LED on system and an AFW-LED off system were separately operated for 10 days. In the AFW-LED on system, the maximum chlorophyll-a concentration of the phytoplankton chamber was four times higher than that of the AFW-LED off system. With artificial nighttime illumination, the microalgae became both smaller and more nutritious; the microalgae became high quality food for the zooplankton, Daphnia magna. Consequently, this zooplankton became more efficient at extracting nutrients and grew more densely than in the AFW-LED off system condition. In the LED-on condition, the amounts of total nitrogen (TN and total phosphorus (TP flowing into the system for 10 days were 84.7 g and 20.4 g, and the amounts flowing out were 19.5 g (23% and 4.0 g (20%, respectively. In contrast, in the LED-off condition, 83.8 g and 20.6 g of TN and TP flowed into the system while 38.8 g (46% and 6.8 g (33% flowed out, respectively. Artificial illumination significantly improves the removal rate of nutrients in an AFW system.

  17. Simultaneous removal of color, organic compounds and nutrients in azo dye-containing wastewater using up-flow constructed wetland. (United States)

    Ong, Soon-An; Uchiyama, Katsuhiro; Inadama, Daisuke; Yamagiwa, Kazuaki


    Combination of aerobic and anaerobic processes in constructed wetlands can enhance the treatment performance in textile wastewater. This study assessed the treatment of azo dye Acid Orange 7 (AO7) and nutrients using five laboratory-scale up-flow constructed wetlands (UFCW) with and without supplementary aeration, and with different emergent plants. Supplementary aeration controlled the size of aerobic and anaerobic zones in the UFCW reactors as evidenced by the oxidation-reduction potential (ORP) and dissolved oxygen (DO) profile of the UFCW. The AO7 removal efficiency was above 95% in all UFCW reactors and most of the color was extensively removed in the anaerobic region of the UFCW beds. The intermediates produced through the breakage of azo bond were significantly reduced in the UFCW reactors with supplementary aeration. The results indicated the applicability of the UFCW reactors to the treatment of azo dye-containing wastewater. The removals of T-N and T-P were in the range of 60-67% and 26-37%, respectively, among the UFCW reactors. The COD and NH(4)-N removals in the aerated reactors were about 86 and 96%, respectively. On the other hand, the COD and NH(4)-N removals were in the range of 78-82% and 41-48%, respectively, in the non-aerated reactors. The supplementary aeration enhanced the removal efficiencies in organic matter, NH(4)-N and aromatic amines in the UFCW reactors.

  18. Effects of organic nutrients and growth factors on biostimulation of tributyltin removal by sediment microorganisms and Enterobacter cloacae. (United States)

    Sakultantimetha, Arthit; Keenan, Helen E; Beattie, Tara K; Bangkedphol, Sornnarin; Cavoura, Olga


    Natural attenuation can reduce contamination of tributyltin (TBT), but persistence of the xenobiotic can cause long-term issues in the environment. Biostimulation is used to accelerate biodegradation. This study investigated the ability of individual organic nutrients and growth factors to enhance TBT biodegradation by sediment microorganisms (SED) and Enterobacter cloacae strain TISTR1971 (B3). The supplements that produced high biomass yield were selected for degradation enhancement. For TBT degradation at initial concentration of 0.1 mg/l, negative or limited degradation was observed in some selected supplements indicating that increasing the biomass did not necessarily promote degradation. Consequently, the addition of nutrients was expected to increase both dioxygenase activity and the degrader population. At different concentrations of supplements, a mixture of succinate/glycerol showed the highest removal for SED which reduced TBT by 77%, 75%, and 68% for 0.1×, 1×, and 10× supplement concentration, respectively. For B3, the addition of succinate showed degradation of 49% (0.1×), 75% (1×), and 77% (10×). Most nutrients and amino acids had an inhibitory effect at 1× or 10× levels. Excess amount of the nutrients added can inhibit the initial degradation of TBT. Therefore, TBT biostimulation requires supplements that increase the capability of TBT degraders at an appropriate amount.

  19. Nutrient regulation by continuous feeding removes limitations on cell yield in the large-scale expansion of Mammalian cell spheroids.

    Directory of Open Access Journals (Sweden)

    Bradley P Weegman

    Full Text Available Cellular therapies are emerging as a standard approach for the treatment of several diseases. However, realizing the promise of cellular therapies across the full range of treatable disorders will require large-scale, controlled, reproducible culture methods. Bioreactor systems offer the scale-up and monitoring needed, but standard stirred bioreactor cultures do not allow for the real-time regulation of key nutrients in the medium. In this study, β-TC6 insulinoma cells were aggregated and cultured for 3 weeks as a model of manufacturing a mammalian cell product. Cell expansion rates and medium nutrient levels were compared in static, stirred suspension bioreactors (SSB, and continuously fed (CF SSB. While SSB cultures facilitated increased culture volumes, no increase in cell yields were observed, partly due to limitations in key nutrients, which were consumed by the cultures between feedings, such as glucose. Even when glucose levels were increased to prevent depletion between feedings, dramatic fluctuations in glucose levels were observed. Continuous feeding eliminated fluctuations and improved cell expansion when compared with both static and SSB culture methods. Further improvements in growth rates were observed after adjusting the feed rate based on calculated nutrient depletion, which maintained physiological glucose levels for the duration of the expansion. Adjusting the feed rate in a continuous medium replacement system can maintain the consistent nutrient levels required for the large-scale application of many cell products. Continuously fed bioreactor systems combined with nutrient regulation can be used to improve the yield and reproducibility of mammalian cells for biological products and cellular therapies and will facilitate the translation of cell culture from the research lab to clinical applications.

  20. Nutrient regulation by continuous feeding removes limitations on cell yield in the large-scale expansion of Mammalian cell spheroids. (United States)

    Weegman, Bradley P; Nash, Peter; Carlson, Alexandra L; Voltzke, Kristin J; Geng, Zhaohui; Jahani, Marjan; Becker, Benjamin B; Papas, Klearchos K; Firpo, Meri T


    Cellular therapies are emerging as a standard approach for the treatment of several diseases. However, realizing the promise of cellular therapies across the full range of treatable disorders will require large-scale, controlled, reproducible culture methods. Bioreactor systems offer the scale-up and monitoring needed, but standard stirred bioreactor cultures do not allow for the real-time regulation of key nutrients in the medium. In this study, β-TC6 insulinoma cells were aggregated and cultured for 3 weeks as a model of manufacturing a mammalian cell product. Cell expansion rates and medium nutrient levels were compared in static, stirred suspension bioreactors (SSB), and continuously fed (CF) SSB. While SSB cultures facilitated increased culture volumes, no increase in cell yields were observed, partly due to limitations in key nutrients, which were consumed by the cultures between feedings, such as glucose. Even when glucose levels were increased to prevent depletion between feedings, dramatic fluctuations in glucose levels were observed. Continuous feeding eliminated fluctuations and improved cell expansion when compared with both static and SSB culture methods. Further improvements in growth rates were observed after adjusting the feed rate based on calculated nutrient depletion, which maintained physiological glucose levels for the duration of the expansion. Adjusting the feed rate in a continuous medium replacement system can maintain the consistent nutrient levels required for the large-scale application of many cell products. Continuously fed bioreactor systems combined with nutrient regulation can be used to improve the yield and reproducibility of mammalian cells for biological products and cellular therapies and will facilitate the translation of cell culture from the research lab to clinical applications.

  1. Biotechnological potential of Synechocystis salina co-cultures with selected microalgae and cyanobacteria: Nutrients removal, biomass and lipid production. (United States)

    Gonçalves, Ana L; Pires, José C M; Simões, Manuel


    Cultivation of microalgae and cyanobacteria has been the focus of several research studies worldwide, due to the huge biotechnological potential of these photosynthetic microorganisms. However, production of these microorganisms is still not economically viable. One possible alternative to improve the economic feasibility of the process is the use of consortia between microalgae and/or cyanobacteria. In this study, Chlorella vulgaris, Pseudokirchneriella subcapitata and Microcystis aeruginosa were co-cultivated with Synechocystis salina to evaluate how dual-species cultures can influence biomass and lipid production and nutrients removal. Results have shown that the three studied consortia achieved higher biomass productivities than the individual cultures. Additionally, nitrogen and phosphorus consumption rates by the consortia provided final concentrations below the values established by European Union legislation for these nutrients. In the case of lipid productivities, higher values were determined when S. salina was co-cultivated with P. subcapitata and M. aeruginosa.

  2. Optimizing cultivation strategies for robust algal growth and consequent removal of inorganic nutrients in pretreated livestock effluent. (United States)

    Kim, Hyun-Chul; Choi, Wook Jin; Ryu, Jun Hee; Maeng, Sung Kyu; Kim, Han Soo; Lee, Byung-Chan; Song, Kyung Guen


    Dilution was employed as a pretreatment strategy to increase light transmittance and decrease ammonia toxicity in piggery effluent prior to the cultivation of microalgae. The dilution effect was quantitatively determined based on both the maximum specific nutrient consumption rate and the maximum growth coefficient to minimize the usage of diluent. The biomass productivity of microalgae was also evaluated to select the best species among the five different candidates examined. A 20-fold dilution of piggery wastewater resulted in decreased chromaticity (584 mg Pt-Co L(-1)) and total nitrogen (76 mg L(-1)), on which the microalgae cultivation was more effective for an algal growth compared to the other dilution factors. If the initial cell concentration of Scenedesmus quadricauda increased, the production of biomass tended to improve. Robust growth and harvesting of S. quadricauda were achieved, and the associated consistent removal of inorganic nutrients was accomplished during the semi-continuous cultivation of the best species.

  3. Physical, Nutrient, and Biological Measurements of Coastal Waters off Central California in March 2012 (United States)


    Oceanography Physical Oceanography Nutrients Nutrients Nutrients Naval Postgraduate School ENS Amber Payne (NOAA)* Cynthia Carrion ...Jolla, CA Cynthia Carrion University of California at Santa Cruz Santa Cruz, CA LT Luke Penrose, USN United States Navy 1 1

  4. Effect of solids retention time and wastewater characteristics on biological phosphorus removal

    DEFF Research Database (Denmark)

    Henze, Mogens; Aspegren, H.; Jansen, J.l.C.


    The paper deals with the effect of wastewater, plant design and operation in relation to biological nitrogen and phosphorus removal and the possibilities to model the processes. Two Bio-P pilot plants were operated for 2.5 years in parallel receiving identical wastewater. The plants had SRT of 4...... with time which has importance in relation to modelling. The overall conclusion of the comparison between the two plants is that the biological phosphorus removal efficiency under practical operating conditions is affected by the SRT in the plant and the wastewater composition. Thus great care should...... in verification of models for Nitrogen and Enhanced Biological Phosphorus Removal....

  5. Fed-batch cultivation of Desmodesmus sp. in anaerobic digestion wastewater for improved nutrient removal and biodiesel production. (United States)

    Ji, Fang; Zhou, Yuguang; Pang, Aiping; Ning, Li; Rodgers, Kibet; Liu, Ying; Dong, Renjie


    Desmodesmus sp. was used in anaerobically digested wastewater (ADW) for nutrients removal and the biodiesel production was measured and compared using fed-batch cultivation was investigated and compared with batch cultivation. The Desmodesmus sp. was able to remove 236.143, 268.238 and 6.427 mg/L of TN, NH4-N and PO4-P respectively after 40 d of fed-batch cultivation, while in batch cultivation the quantities of TN, NH4-N and PO4-P removed were 33.331, 37.227 and 1.323 mg/L. Biomass production of Desmodesmus sp. was also enhanced in fed-batch cultivation, when ADW loading was carried out every 2 days; the biomass concentration peaked at 1.039 g/L, which was three times higher than that obtained in batch cultivation (0.385 g/L). The highest lipid production (261.8 mg/L) was also recorded in fed-batch cultivation as compared to batch cultivation (83.3 mg/L). Fed-batch cultivation of Desmodesmus sp. could provide effective control of nutrients limitation and/or ammonia inhibition on microalgae cultivation.

  6. Effects of different influent C/N ratios on the performance of various earthworm eco-filter systems: nutrient removal and greenhouse gas emission. (United States)

    Huang, Wei; Zhao, Yongjun; Wu, Jiangtao; Zhang, Jibiao; Zheng, Zheng


    In this study, we sought to identify influent carbon-to-nitrogen (C/N) ratios that yield relatively high nutrient removal efficiency with relatively low greenhouse gas (GHG) emissions. The earthworm eco-filter (EE) system, which is composed of earthworms and plants (EP group), was found to be optimal for maximizing nutrient removal while reducing GHG emissions. In this EE system, the optimal influent C/N ratio for nutrient removal and GHG emission under C2N treatment conditions. Nutrient removal efficiency under this condition was 85.19 ± 6.40% chemical oxygen demand, 71.99 ± 11.28% total nitrogen, and 77.91 ± 8.51% total phosphorus, while the CO2 emission rate was 678.89 ± 201.87 mg m(-2) h(-1). Moreover, the highest nutrient removal and GHG emission rates were both achieved in late summer (August). Thus, carbon variation, season, system variation, as well as synergistic interaction between system variations and seasons, significantly affect nutrient removal efficiencies and GHG emissions.

  7. Soil fertility in deserts: a review on the influence of biological soil crusts and the effect of soil surface disturbance on nutrient inputs and losses (United States)

    Reynolds, R.; Phillips, S.; Duniway, M.; Belnap, J.


    Sources of desert soil fertility include parent material weathering, aeolian deposition, and on-site C and N biotic fixation. While parent materials provide many soil nutrients, aeolian deposition can provide up to 75% of plant-essential nutrients including N, P, K, Mg, Na, Mn, Cu, and Fe. Soil surface biota are often sticky, and help retain wind-deposited nutrients, as well as providing much of the N inputs. Carbon inputs are from both plants and soil surface biota. Most desert soils are protected by cyanobacterial-lichen-moss soil crusts, chemical crusts and/or desert pavement. Experimental disturbances applied in US deserts show disruption of soil surfaces result in decreased N and C inputs from soil biota by up to 100%. The ability to glue aeolian deposits in place is compromised, and underlying soils are exposed to erosion. The ability to withstand wind increases with biological and physical soil crust development. While most undisturbed sites show little sediment production, disturbance by vehicles or livestock produce up to 36 times more sediment production, with soil movement initiated at wind velocities well below commonly-occurring wind speeds. Soil fines and flora are often concentrated in the top 3 mm of the soil surface. Winds across disturbed areas can quickly remove this material from the soil surface, thereby potentially removing much of current and future soil fertility. Thus, disturbances of desert soil surfaces can both reduce fertility inputs and accelerate fertility losses.


    Institute of Scientific and Technical Information of China (English)


    @@Baesd on the survey in 1997 fiscal year, we have been making a further survey and study together with 中国石油(Petro China) at Liaohe Refinery since 1998 fiscal year, aiming at the transfer of Japanese waste water treating technologies to China.   Scope is as follows:   (1) Demonstration of a new waste water treating technology, a kind of biological treating methods (Fluidized bed biological treatment), to eliminate phenols in FCCU effluent.   (2) Recommendation of eliminating pollutant and reducing total effluent by improving the operation.    1 Fluidized bed biological treatment 1.1 What is fluidized bed biological treatment   Fluidized bed biological treatment is the process to treat waste water as follows:   (1) To put biologically inert granular matters (fluidized carrier) into an aeration tank;   (2) Homogeneously and entirely to fluidize the particles in the tank to form highly active biofilm on the surface of each particle;   (3) To contact organic substances with these microorganisms to purify the waste water.   The surface area of the particle per unit volume is about ten times as large as that in conventional biofilm treatment process. In addition, no blockade of the filler (carrier) may be caused. Accordingly, volumetric loading of the aeration tank can be improved to attain highly efficient treatment.

  9. Nutrient removal by NF and RO membranes in a decentralized sanitation system

    NARCIS (Netherlands)

    Voorthuizen, van Ellen M.; Zwijnenburg, Arie; Wessling, Matthias


    Decentralized treatment of domestic wastewater offers the possibility of water and nutrient reuse. In a decentralized sanitation system the household wastewater streams are separated in a large diluted stream (gray water) and a small and concentrated stream (black water) containing important nutrien

  10. Including Life Cycle Assessment for decision-making in controlling wastewater nutrient removal systems

    DEFF Research Database (Denmark)

    Corominas, Lluís; Larsen, Henrik Fred; Flores-Alsina, Xavier


    This paper focuses on the use of Life Cycle Assessment (LCA) to evaluate the performance of seventeen control strategies in wastewater treatment plants (WWTPs). It tackles the importance of using site-specific factors for nutrient enrichment when decision-makers have to select best operating stra...

  11. Macrophytes may not contribute significantly to removal of nutrients, pharmaceuticals, and antibiotic resistance in model surface constructed wetlands. (United States)

    Cardinal, Pascal; Anderson, Julie C; Carlson, Jules C; Low, Jennifer E; Challis, Jonathan K; Beattie, Sarah A; Bartel, Caitlin N; Elliott, Ashley D; Montero, Oscar F; Lokesh, Sheetal; Favreau, Alex; Kozlova, Tatiana A; Knapp, Charles W; Hanson, Mark L; Wong, Charles S


    Outdoor shallow wetland mesocosms, designed to simulate surface constructed wetlands to improve lagoon wastewater treatment, were used to assess the role of macrophytes in the dissipation of wastewater nutrients, selected pharmaceuticals, and antibiotic resistance genes (ARGs). Specifically, mesocosms were established with or without populations of Typha spp. (cattails), Myriophyllum sibiricum (northern water milfoil), and Utricularia vulgaris (bladderwort). Following macrophyte establishment, mesocosms were seeded with ARG-bearing organisms from a local wastewater lagoon, and treated with a single pulse of artificial municipal wastewater with or without carbamazepine, clofibric acid, fluoxetine, and naproxen (each at 7.6μg/L), as well as sulfamethoxazole and sulfapyridine (each at 150μg/L). Rates of pharmaceutical dissipation over 28d ranged from 0.073 to 3.0d(-1), corresponding to half-lives of 0.23 to 9.4d. Based on calculated rate constants, observed dissipation rates were consistent with photodegradation driving clofibric acid, naproxen, sulfamethoxazole, and sulfapyridine removal, and with sorption also contributing to carbamazepine and fluoxetine loss. Of the seven gene determinants assayed, only two genes for both beta-lactam resistance (blaCTX and blaTEM) and sulfonamide resistance (sulI and sulII) were found in sufficient quantity for monitoring. Genes disappeared relatively rapidly from the water column, with half-lives ranging from 2.1 to 99d. In contrast, detected gene levels did not change in the sediment, with the exception of sulI, which increased after 28d in pharmaceutical-treated systems. These shallow wetland mesocosms were able to dissipate wastewater contaminants rapidly. However, no significant enhancement in removal of nutrients or pharmaceuticals was observed in mesocosms with extensive aquatic plant communities. This was likely due to three factors: first, use of naïve systems with an unchallenged capacity for nutrient assimilation and

  12. Population dynamics in wastewater treatment plants with enhanced biological phosphorus removal operated with and without nitrogen removal

    DEFF Research Database (Denmark)

    Lee, N.; Jansen, J.l.C.; Aspegren, H.


    The population dynamics of activated sludge in a pilot plant with two activated sludge systems, both designed for enhanced biological phosphorus removal (EBPR), but one of them with (BNP) and the other without (BP) nitrogen removal, was monitored during a period of 2.5 years. The influent water...... to the pilot plant was periodically manipulated by external addition of phosphorus (P), acetate and glucose, respectively. The population dynamics and the in situ physiology were monitored by quantitative fluorescence in situ hybridization (FISH) and microautoradiography. Significant P removal was observed...... in both systems throughout the whole period, with significant increases of the P removal when substrates were dosed. The activated sludge in both systems contained large amounts of dense clusters of gram-negative, methylene-blue staining coccoid rods during the whole period. A large part of the clusters...

  13. State Estimation for a Biological Phosphorus Removal Process using an Asymptotic Observer

    DEFF Research Database (Denmark)

    Larose, Claude Alain; Jørgensen, Sten Bay


    This study investigated the use of an asymptotic observer for state estimation in a continuous biological phosphorus removal process. The estimated states are the concentration of heterotrophic, autotrophic, and phosphorus accumulating organisms, polyphosphate, glycogen and PHA. The reaction scheme...

  14. A sequencing batch reactor system for high-level biological nitrogen and phosphorus removal from abattoir wastewater. (United States)

    Lemaire, Romain; Yuan, Zhiguo; Bernet, Nicolas; Marcos, Marcelino; Yilmaz, Gulsum; Keller, Jürg


    A sequencing batch reactor (SBR) system is demonstrated to biologically remove nitrogen, phosphorus and chemical oxygen demand (COD) to very low levels from abattoir wastewater. Each 6 h cycle contained three anoxic/anaerobic and aerobic sub-cycles with wastewater fed at the beginning of each anoxic/anaerobic period. The step-feed strategy was applied to avoid high-level build-up of nitrate or nitrite during nitrification, and therefore to facilitate the creation of anaerobic conditions required for biological phosphorus removal. A high degree removal of total phosphorus (>98%), total nitrogen (>97%) and total COD (>95%) was consistently and reliably achieved after a 3-month start-up period. The concentrations of total phosphate and inorganic nitrogen in the effluent were consistently lower than 0.2 mg P l(-1) and 8 mg N l(-1), respectively. Fluorescence in situ hybridization revealed that the sludge was enriched in Accumulibacter spp. (20-40%), a known polyphosphate accumulating organism, whereas the known glycogen accumulating organisms were almost absent. The SBR received two streams of abattoir wastewater, namely the effluent from a full-scale anaerobic pond (75%) and the effluent from a lab-scale high-rate pre-fermentor (25%), both receiving raw abattoir wastewater as feed. The pond effluent contained approximately 250 mg N l(-1) total nitrogen and 40 mg P l(-1) of total phosphorus, but relatively low levels of soluble COD (around 500 mg l(-1)). The high-rate lab-scale pre-fermentor, operated at 37 degrees C and with a sludge retention time of 1 day, proved to be a cheap and effective method for providing supplementary volatile fatty acids allowing for high-degree of biological nutrient removal from abattoir wastewater.


    Directory of Open Access Journals (Sweden)

    Y.C. WEE and H.H. YEOH


    Full Text Available Profuse growth of Eichhornia crassipes and Salvinia molesta in Singapore reservoirs required their regular manual removal as their prolonged presence can lead to deterioration in the quality of the potable water. Clearing of the reservoir catchments, together with regular removal of the weeds and dumping them away from the catchments, should, in the long term, reduce their presence in the reservoirs. Laboratory experiments showing the removal of chloride, sulphate, phosphorus and nitrate from the growing medium and the release of chloride, phosphorus and nitrate by rotting plants should convince the administrators of the benefit of proper management of the problem.

  16. Electricity generation and nutrients removal from high-strength liquid manure by air-cathode microbial fuel cells. (United States)

    Lin, Hongjian; Wu, Xiao; Nelson, Chad; Miller, Curtis; Zhu, Jun


    Air-cathode microbial fuel cells (MFCs) are widely tested to recover electrical energy from waste streams containing organic matter. When high-strength wastewater, such as liquid animal manure, is used as a medium, inhibition on anode and cathode catalysts potentially impairs the effectiveness of MFC performance in power generation and pollutant removal. This study evaluated possible inhibitive effects of liquid swine manure components on MFC power generation, improved liquid manure-fed MFCs performance by pretreatment (dilution and selective adsorption), and modeled the kinetics of organic matter and nutrients removal kinetics. Parameters monitored included pH, conductivity, chemical oxygen demand (COD), volatile fatty acids (VFAs), total ammoniacal nitrogen (TAN), nitrite, nitrate, and phosphate concentrations. The removals of VFA and TAN were efficient, indicated by the short half-life times of 4.99 and 7.84 d, respectively. The mechanism for phosphate decrease was principally the salt precipitation on cathode, but the removal was incomplete after 42-d operation. MFC with an external resistor of 2.2 kΩ and fed with swine wastewater generated relatively small power (28.2 μW), energy efficiency (0.37%) and Coulombic efficiency (1.5%). Dilution of swine wastewater dramatically improved the power generation as the inhibitory effect was decreased. Zeolite and granular activated carbon were effective in the selective adsorption of ammonia or organic matter in swine wastewater, and so substantially improved the power generation, energy efficiency, and Coulombic efficiency. A smaller external resistor in the circuit was also observed to promote the organic matter degradation and thus to shorten the treatment time. Overall, air-cathode MFCs are promising for generating electrical power from livestock wastewater and meanwhile reducing the level of organic matter and nutrients.

  17. Full-Scale Implementation of a Vertical Membrane Bioreactor for Simultaneous Removal of Organic Matter and Nutrients from Municipal Wastewater

    Directory of Open Access Journals (Sweden)

    So-Ryong Chae


    Full Text Available In nutrient-sensitive estuaries, wastewater treatment plants (WWTPs are required to implement more advanced treatment methods in order to meet increasingly stringent effluent guidelines for organic matter and nutrients. To comply with current and anticipated water quality regulations and to reduce the volume of produced sludge, we have successfully developed a vertical membrane bioreactor (VMBR that is composed of anoxic (lower layer and oxic (upper layer zones in one reactor. Since 2009, the VMBR has been commercialized (Q = 1100–16,000 m3/d under the trade-name of DMBRTM for recycling of municipal wastewater in South Korea. In this study, we explore the performance and stability of the full-scale systems. As a result, it was found that the DMBRTM systems showed excellent removal efficiencies of organic substances, suspended solids (SS and Escherichia coli (E. coli. Moreover, average removal efficiencies of total nitrogen (TN and total phosphorus (TP by the DMBRTM systems were found to be 79% and 90% at 18 °C, 8.3 h HRT and 41 d SRT. Moreover, transmembrane pressure (TMP was maintained below 40 kPa at a flux of 18 L/m2/h (LMH more than 300 days. Average specific energy consumption of the full-scale DMBRTM systems was found to be 0.94 kWh/m3.

  18. Microalgal-biotechnology as a platform for an integral biogas upgrading and nutrient removal from anaerobic effluents. (United States)

    Bahr, Melanie; Díaz, Ignacio; Dominguez, Antonio; González Sánchez, Armando; Muñoz, Raul


    The potential of a pilot high rate algal pond (HRAP) interconnected via liquid recirculation with an external absorption column for the simultaneous removal of H2S and CO2 from biogas using an alkaliphilic microalgal-bacterial consortium was evaluated. A bubble column was preferred as external absorption unit to a packed bed column based on its ease of operation, despite showing a comparable CO2 mass transfer capacity. When the combined HRAP-bubble column system was operated under continuous mode with mineral salt medium at a biogas residence time of 30 min in the absorption column, the system removed 100% of the H2S (up to 5000 ppmv) and 90% of the CO2 supplied, with O2 concentrations in the upgraded biogas below 0.2%. The use of diluted centrates as a free nutrient source resulted in a gradual decrease in CO2 removal to steady values of 40%, while H2S removal remained at 100%. The anaerobic digestion of the algal-bacterial biomass produced during biogas upgrading resulted in a CH4 yield of 0.21-0.27 L/gVS, which could satisfy up to 60% of the overall energy demand for biogas upgrading. This proof of concept study confirmed that algal-bacterial photobioreactors can support an integral upgrading without biogas contamination, with a net negative CO2 footprint, energy production, and a reduction of the eutrophication potential of the residual anaerobic effluents.

  19. Bioremediation efficiency in the removal of dissolved inorganic nutrients by the red seaweed, Porphyra yezoensis, cultivated in the open sea. (United States)

    He, Peimin; Xu, Shannan; Zhang, Hanye; Wen, Shanshan; Dai, Yongjing; Lin, Senjie; Yarish, Charles


    The bioremediation capability and efficiency of large-scale Porphyra cultivation in the removal of inorganic nitrogen and phosphorus from open sea area were studied. The study took place in 2002-2004, in a 300 ha nori farm along the Lusi coast, Qidong County, Jiangsu Province, China, where the valuable rhodophyte seaweed Porphyra yezoensis has been extensively cultivated. Nutrient concentrations were significantly reduced by the seaweed cultivation. During the non-cultivation period of P. yezoensis, the concentrations of NH4-N, NO2-N, NO3-N and PO4-P were 43-61, 1-3, 33-44 and 1-3 micromol L(-1), respectively. Within the Porphyra cultivation area, the average nutrient concentrations during the Porphyra cultivation season were 20.5, 1.1, 27.9 and 0.96 micromol L(-1) for NH4-N, NO2-N, NO3-N and PO4-P, respectively, significantly lower than in the non-cultivation season (p0.05). The highest tissue nitrogen content, 7.65% in dry wt, was found in December and the lowest value, 4.85%, in dry wt, in April. The annual biomass production of P. yezoensis was about 800 kg dry wt ha(-1) at the Lusi Coast in 2003-2004. An average of 14708.5 kg of tissue nitrogen and 2373.5 kg of tissue phosphorus in P. yezoensis biomass were harvested annually from 300 ha of cultivation from Lusi coastal water. These results indicated that Porphyra efficiently removed excess nutrient from nearshore eutrophic coastal areas. Therefore, large-scale cultivation of P. yezoensis could alleviate eutrophication in coastal waters economically.

  20. Sand filters for removal of microbes and nutrients from wastewater during a one-year pilot study in a cold temperate climate. (United States)

    Kauppinen, Ari; Martikainen, Kati; Matikka, Ville; Veijalainen, Anna-Maria; Pitkänen, Tarja; Heinonen-Tanski, Helvi; Miettinen, Ilkka T


    Onsite wastewater treatment systems (OWTS) are recognised as potential threats to groundwater or other water environments subject to discharged effluents. In this study, the microbiological and nutrient removal properties of three different pilot-scale sand filters (SFs) were followed over a one-year period. Moreover, a separate phosphorus removal unit was tested for six months. For the best treatment system, the average log removals were 2.2-3.5 for pathogenic human noro- and adenoviruses and 4.3-5.2 and 4.6-5.4 for indicator viruses and bacteria, respectively. The system that effectively removed microbes was also efficient at removing nutrients. However, the poorest treatment system yielded substantially lower removals. The remarkable differences noted between the studied SFs highlights the importance of construction materials and the careful planning of the filters. Moreover, seasonal conditions appear to have a clear effect on purification efficiencies, emphasising the vulnerability of these systems especially in cold climates.

  1. Identification of a novel group of bacteria in sludge from a deteriorated biological phosphorus removal reactor

    DEFF Research Database (Denmark)

    Nielsen, Alex Toftgaard; Liu, Wen-Tso; Filipe, Carlos


    The microbial diversity of a deteriorated biological phosphorus removal reactor was investigated by methods not requiring direct cultivation. The reactor was fed with media containing acetate and high levels of phosphate (P/C weight ratio, 8:100) but failed to completely remove phosphate...... in the effluent and showed very limited biological phosphorus removal activity. Denaturing gradient gel electrophoresis (DGGE) of PCR-amplified 16S ribosomal DNA was used to investigate the bacterial diversity. Up to 11 DGGE bands representing at least 11 different sequence types were observed; DNA from the 6...

  2. Enhanced biological phosphorus removal from activated sludge system; Eliminacion biologica del fosfor en aguas residuales

    Energy Technology Data Exchange (ETDEWEB)

    Pidre Bocardo, J. R.; Toja Santillana, J.; Alonso Alvarez, E. [Sevilla (Spain)


    A literature review of enhanced biological phosphorus removal was performed. This biological removal is based on the selective enrichment of bacteria accumulating inorganic polyphosphate, obtained at a cyclic regime of alternating anaerobic and aerobic conditions; or anaerobic, anoxic and aerobic zones for combined nitrogen and phosphorus removal. Some bacterial groups may to be implicate in this process, the gen Acinetobacter has been the most studied. In this paper a study of phosphorate forms from wastewater for a conventional activated sludge system is presented. (Author) 40 refs.

  3. The Impact of Temperature on Anaerobic Biological Perchlorate Removal and Aerobic Polishing of the Effluent (United States)

    This abstract describes a pilot-scale evaluation of anaerobic biological perchlorate (C1O4) removal followed by aerobic effluent polishing. The anaerobic biological contactor operated for 3.5 years. During that period, two effluent polishing evaluations, lasting 311 an...

  4. The Impact of Temperature on Anaerobic Biological Perchlorate Removal and Aerobic Polishing of the Effluent - paper (United States)

    This abstract describes a pilot-scale evaluation of anaerobic biological perchlorate (C1O4) removal followed by aerobic effluent polishing. The anaerobic biological contactor operated for 3.5 years. During that period, two effluent polishing evaluations, lasting 311 an...

  5. Hybrid Adsorption-Membrane Biological Reactors for Improved Performance and Reliability of Perchlorate Removal Processes (United States)


    carbon supply for the autotrophic perchlorate reducing bacteria. The membrane used in the reactor is a hollow-fiber microfiltration membrane made from...1 HYBRID ADSORPTION- MEMBRANE BIOLOGICAL REACTORS FOR IMPROVED PERFORMANCE AND RELIABILITY OF PERCHLORATE REMOVAL PROCESSES L.C. Schideman...Center Champaign, IL 61826, USA ABSTRACT This study introduces the novel HAMBgR process (Hybrid Adsorption Membrane Biological Reactor) and

  6. A novel membrane distillation-thermophilic bioreactor system: biological stability and trace organic compound removal. (United States)

    Wijekoon, Kaushalya C; Hai, Faisal I; Kang, Jinguo; Price, William E; Guo, Wenshan; Ngo, Hao H; Cath, Tzahi Y; Nghiem, Long D


    The removal of trace organic compounds (TrOCs) by a novel membrane distillation-thermophilic bioreactor (MDBR) system was examined. Salinity build-up and the thermophilic conditions to some extent adversely impacted the performance of the bioreactor, particularly the removal of total nitrogen and recalcitrant TrOCs. While most TrOCs were well removed by the thermophilic bioreactor, compounds containing electron withdrawing functional groups in their molecular structure were recalcitrant to biological treatment and their removal efficiency by the thermophilic bioreactor was low (0-53%). However, the overall performance of the novel MDBR system with respect to the removal of total organic carbon, total nitrogen, and TrOCs was high and was not significantly affected by the conditions of the bioreactor. All TrOCs investigated here were highly removed (>95%) by the MDBR system. Biodegradation, sludge adsorption, and rejection by MD contribute to the removal of TrOCs by MDBR treatment.

  7. Riparian and Associated Habitat Characteristics Related to Nutrient Concentrations and Biological Responses of Small Streams in Selected Agricultural Areas, United States, 2003-04 (United States)

    Zelt, Ronald B.; Munn, Mark D.


    sampled sites. The habitat characteristics sampled within the five study units were compared statistically. Bivariate correlations between riparian habitat variables and either nutrient-chemistry or biological-response variables were examined for all sites combined, and for sites within each study area. Nutrient concentrations were correlated with the extent of riparian cropland. For nitrogen species, these correlations were more frequently at the basin scale, whereas for phosphorus, they were about equally frequent at the segment and basin scales. Basin-level extents of riparian cropland and reach-level bank vegetative cover were correlated strongly with both total nitrogen and dissolved inorganic nitrogen (DIN) among multiple study areas, reflecting the importance of agricultural land-management and conservation practices for reducing nitrogen delivery from near-stream sources. When sites lacking segment-level wetlands were excluded, the negative correlation of riparian wetland extent with DIN among 49 sites was strong at the reach and segment levels. Riparian wetland vegetation thus may be removing dissolved nutrients from soil water and shallow groundwater passing through riparian zones. Other habitat variables that correlated strongly with nitrogen and phosphorus species included suspended sediment, light availability, and antecedent water temperature. Chlorophyll concentrations in seston were positively correlated with phosphorus concentrations for all sites combined. Benthic chlorophyll was correlated strongly with nutrient concentrations in only the Delmarva study area and only in fine-grained habitats. Current velocity or hydraulic scour could explain correlation patterns for benthic chlorophyll among Georgia sites, whereas chlorophyll in seston was correlated with antecedent water temperature among Washington and Delmarva sites. The lack of any consistent correlation pattern between habitat characteristics and organic material density (ash-free dry mass)

  8. Biological regeneration of ferric (Fe3+) solution during desulphurisation of gaseous streams: effect of nutrients and support material. (United States)

    Mulopo, Jean; Schaefer, L


    This paper evaluates the biological regeneration of ferric Fe3+ solution during desulphurisation of gaseous streams. Hydrogen sulphide (H2S) is absorbed into aqueous ferric sulphate solution and oxidised to elemental sulphur, while ferric ions Fe3+ are reduced to ferrous ions Fe2+. During the industrial regeneration of Fe3+, nutrients and trace minerals usually provided in a laboratory setup are not present and this depletion of nutrients may have a negative impact on the bacteria responsible for ferrous iron oxidation and may probably affect the oxidation rate. In this study, the effect of nutrients and trace minerals on ferrous iron oxidation have been investigated and the results showed that the presence of nutrients and trace minerals affects the efficiency of bacterial Fe2+oxidation. The scanning electron microscopy analysis of the geotextile support material was also conducted and the results showed that the iron precipitate deposits appear to play a direct role on the bacterial biofilm formation.

  9. Scenario Analysis of Nutrient Removal from Municipal Wastewater by Microalgal Biofilms

    NARCIS (Netherlands)

    Boelee, N.C.; Temmink, H.; Janssen, M.; Buisman, C.J.N.; Wijffels, R.H.


    Microalgae can be used for the treatment of municipal wastewater. The application of microalgal biofilms in wastewater treatment systems seems attractive, being able to remove nitrogen, phosphorus and COD from wastewater at a short hydraulic retention time. This study therefore investigates the area

  10. Green-cane harvest of sugarcane effects on biomass and energy yields and nutrient removal (United States)

    Sugarcane yields in Louisiana can approach 40 dry Mg ha-1, making sugarcane an attractive biofuel feedstock as well as a profitable sugar crop. Existing technology used in green-cane harvesting can be used to allow chopper harvester extractor fans to remove variable amounts of extraneous leaf materi...

  11. The effect of nutrient supplementation on the biofiltration removal of butanal in contaminated air

    NARCIS (Netherlands)

    Weckhuysen, B.M.; Vriens, L.; Verachtert, H.


    Butanal is one of the odorous compounds produced in the animal-rendering and food-processing industries and also in sewage-treatment plants. It shows the necessity for complementing such plants with systems for off-gas treatment. Biofiltration using simple packing material was tested for the removal

  12. Removal of nutrients from septic tank effluent with baffle subsurface-flow constructed wetlands. (United States)

    Cui, Lihua; Ouyang, Ying; Yang, Weizhi; Huang, Zhujian; Xu, Qiaoling; Yu, Guangwei


    Three new baffle flow constructed wetlands (CWs), namely the baffle horizontal flow CW (Z1), baffle vertical flow CW (Z2) and baffle hybrid flow CW (Z3), along with one traditional horizontal subsurface flow CW (Z4) were designed to test the removal efficiency of nitrogen (N) and phosphorus (P) from the septic tank effluent under varying hydraulic retention times (HRTs). Results showed that the optimal HRT was two days for maximal removal of N and P from the septic tank effluent among the four CWs. At this HRT, the Z1, Z2, Z3 and Z4 CWs removed, respectively, 49.93, 58.50, 46.01 and 44.44% of TN as well as 87.82, 93.23, 95.97 and 91.30% of TP. Our study further revealed that the Z3 CW was the best design for overall removal of N and P from the septic tank effluent due to its hybrid flow directions with better oxygen supply inside the CW system.

  13. 生物除磷的机理及工艺%Mechanism and Processes of Biological Phosphorus Removal

    Institute of Scientific and Technical Information of China (English)



    水体富营养化是世界性难题,其中磷是主要限制因子。生物除磷工艺具有结构简单、污泥产量少、运行费用较低、便于操作和磷的回收等优点。在介绍PAO和DPB除磷原理的基础上,综述国内外生物除磷的研究进展,并介绍应用较多的除磷工艺,以供污水防治参考。%The phosphorus is the limited nutrient in eutrophication of the waterbody,which is a significant worldwide problem. The process of biological removal of phosphorus in waterbody is structure simple, sludge production less,low-cost,convenient in operation and reelaimation. Based on the introduction of the mechanism of PAO and DPB ,the updated progresses and processes in biological removal of phosphorus in waterbody were summarized in this paper, so as to provide references for the control of waste water.

  14. Nutrient availability affects pigment production but not growth in lichens of biological soil crusts (United States)

    Bowker, M.A.; Koch, G.W.; Belnap, J.; Johnson, N.C.


    Recent research suggests that micronutrients such as Mn may limit growth of slow-growing biological soil crusts (BSCs) in some of the drylands of the world. These soil surface communities contribute strongly to arid ecosystem function and are easily degraded, creating a need for new restoration tools. The possibility that Mn fertilization could be used as a restoration tool for BSCs has not been tested previously. We used microcosms in a controlled greenhouse setting to investigate the hypothesis that Mn may limit photosynthesis and consequently growth in Collema tenax, a dominant N-fixing lichen found in BSCs worldwide. We found no evidence to support our hypothesis; furthermore, addition of other nutrients (primarily P, K, and Zn) had a suppressive effect on gross photosynthesis (P = 0.05). We also monitored the growth and physiological status of our microcosms and found that other nutrients increased the production of scytonemin, an important sunscreen pigment, but only when not added with Mn (P = 0.01). A structural equation model indicated that this effect was independent of any photosynthesis-related variable. We propose two alternative hypotheses to account for this pattern: (1) Mn suppresses processes needed to produce scytonemin; and (2) Mn is required to suppress scytonemin production at low light, when it is an unnecessary photosynthate sink. Although Mn fertilization does not appear likely to increase photosynthesis or growth of Collema, it could have a role in survivorship during environmentally stressful periods due to modification of scytonemin production. Thus, Mn enrichment should be studied further for its potential to facilitate BSC rehabilitation. ?? 2008 Elsevier Ltd.

  15. Effect of carbon source on biomass growth and nutrients removal of Scenedesmus obliquus for wastewater advanced treatment and lipid production. (United States)

    Shen, Qiao-Hui; Jiang, Jia-Wei; Chen, Li-Ping; Cheng, Li-Hua; Xu, Xin-Hua; Chen, Huan-Lin


    The combination of tertiary wastewater treatment and microalgal lipid production is considered to be a promising approach to water eutrophication as well as energy crisis. To intensify wastewater treatment and microalgal biofuel production, the effect of organic and inorganic carbon on algal growth and nutrient removal of Scenedesmus obliquus were examined by varying TOC (total organic carbon) concentrations of 20-120mgL(-1) in wastewater and feeding CO2 concentrations in the range of 0.03-15%, respectively. The results showed that the maximal biomass and average lipid productivity were 577.6 and 16.7mgL(-1)d(-1) with 5% CO2 aeration. The total nitrogen, total phosphorus and TOC removal efficiencies were 97.8%, 95.6% and 59.1% respectively within 6days when cultured with real secondary municipal wastewater. This work further showed that S. obliquus could be utilized for simultaneous organic pollutants reduction, N, P removal and lipid accumulation.

  16. Effect of algae growth on aerobic granulation and nutrients removal from synthetic wastewater by using sequencing batch reactors. (United States)

    Huang, Wenli; Li, Bing; Zhang, Chao; Zhang, Zhenya; Lei, Zhongfang; Lu, Baowang; Zhou, Beibei


    The effect of algae growth on aerobic granulation and nutrients removal was studied in two identical sequencing batch reactors (SBRs). Sunlight exposure promoted the growth of algae in the SBR (Rs), forming an algal-bacterial symbiosis in aerobic granules. Compared to the control SBR (Rc), Rs had a slower granulation process with granules of loose structure and smaller particle size. Moreover, the specific oxygen uptake rate was significantly decreased for the granules from Rs with secretion of 25.7% and 22.5% less proteins and polysaccharides respectively in the extracellular polymeric substances. Although little impact was observed on chemical oxygen demand (COD) removal, algal-bacterial symbiosis deteriorated N and P removals, about 40.7-45.4% of total N and 44% of total P in Rs in contrast to 52.9-58.3% of TN and 90% of TP in Rc, respectively. In addition, the growth of algae altered the microbial community in Rs, especially unfavorable for Nitrospiraceae and Nitrosomonadaceae.

  17. A new hybrid treatment system of bioreactors and electrocoagulation for superior removal of organic and nutrient pollutants from municipal wastewater. (United States)

    Nguyen, Dinh Duc; Ngo, Huu Hao; Yoon, Yong Soo


    This paper evaluated a novel pilot scale hybrid treatment system which combines rotating hanging media bioreactor (RHMBR), submerged membrane bioreactor (SMBR) along with electrocoagulation (EC) as post treatment to treat organic and nutrient pollutants from municipal wastewater. The results indicated that the highest removal efficiency was achieved at the internal recycling ratio as 400% of the influent flow rate which produced a superior effluent quality with 0.26mgBOD5L(-1), 11.46mgCODCrL(-1), 0.00mgNH4(+)-NL(-1), and 3.81mgT-NL(-1), 0.03mgT-PL(-1). During 16months of operation, NH4(+)-N was completely eliminated and T-P removal efficiency was also up to 100%. It was found that increasing in internal recycling ratio could improve the nitrate and nitrogen removal efficiencies. Moreover, the TSS and coliform bacteria concentration after treatment was less than 5mgL(-1) and 30MPNmL(-1), respectively, regardless of internal recycling ratios and its influent concentration.

  18. In situ biological resources: Soluble nutrients and electrolytes in carbonaceous asteroids/meteorites. Implications for astroecology and human space populations (United States)

    Mautner, Michael N.


    Ecosystems in space will need in-situ bioavailable nutrients. The measured nutrients in meteorites allow experiment-based estimates of nutrients in asteroids, and of the biomass and populations that can be derived from these in situ bioresources. In this respect, we found that carbonaceous chondrite meteorites can support microorganisms and plant cultures, suggesting that similar asteroid materials are also biologically fertile. The sustainable biomass and populations are determined by the available resource materials, their yields of nutrients and biomass, the biomass needed to support human populations, the duration of the ecosystem, and wastage. The bioavailable C, N, and electrolytes in carbonaceous chondrite meteorites vary as CM2>CR2>CV3>CO3>CK4>CK5 in correlation with petrologic type, including aqueous alteration. Their average bioavailable C, N, K and P can yield 2.4, 3.5, 2.5, and 0.08 g biomass/kg resource material, respectively, showing phosphorus as the limiting nutrient. On this basis, soluble nutrients in a 100 km radius, 1019 kg resource asteroid can sustain an ecosystem of 108 kg biomass and a human population of 10,000 for >109 years, and its total nutrient contents can sustain a population of one million, by replacing a wastage of 1% of the biomass per year. Overall, the total nutrient contents of the 1022 kg carbonaceous asteroids can yield a biomass of 1020 kg that supports a steady-state human population of one billion during the habitable future of the Solar System, contributing a time-integrated biomass of 1022 kg-years. These astroecology estimates use experimental data on nutrients in asteroids/meteorites to quantify the sustainable biomass and human populations in this and similar solar systems.

  19. Investigation into ammonia stress on Cyperus alternifolius and its impact on nutrient removal in microcosm experiments. (United States)

    Tao, Wendong; Han, Jianqiu; Li, Hanyan


    Ammonia stress on plants has been investigated at discrete ammonia concentrations in constructed wetlands. This study introduced a Gaussian model to simulate the kinetics of ammonia stress and investigated reversible and irreversible ammonia stress on Cyperus alternifolius in wetland-like microcosms. Ammonia stress on plant weight increase and oxygen release potential started at weekly ammonia concentrations of 27 and 28 mg N/L, reached 50% inhibition at 178 and 158 mg N/L, and resulted in lethal effects at 311 and 303 mg N/L, respectively. The stress of one-time ammonia concentrations up to 400 mg N/L could be reversible. Ammonia concentrations constantly above 219 mg N/L exerted irreversible stress. In the microcosms with ammonia concentrations above the 50% inhibition levels, plants played a minor role in nitrogen removal. Nitrogen removal performance was not affected considerably by ammonia stress. Orthophosphate removal was suppressed by ammonia stress due to less plant uptake. Design and operation of constructed wetlands should consider wastewater ammonia concentration so that the integrity of constructed wetland ecosystems can be maintained.

  20. Changes in nutrient profile of soil subjected to bioleaching for removal of heavy metals using Acidithiobacillus thiooxidans

    Energy Technology Data Exchange (ETDEWEB)

    NareshKumar, R. [Centre for Environmental Studies, Anna University, Chennai 600025 (India)], E-mail:; Nagendran, R. [Centre for Environmental Studies, Anna University, Chennai 600025 (India)


    Studies were carried out to assess changes in nitrogen, phosphorus and potassium contents in soil during bioleaching of heavy metals from soil contaminated by tannery effluents. Indigenous sulfur oxidizing bacteria Acidithiobacillus thiooxidans isolated from the contaminated soil were used for bioremediation. Solubilization efficiency of chromium, cadmium, copper and zinc from soil was 88, 93, 92 and 97%, respectively. However, loss of nitrogen, phosphorus and potassium from the soil was 30, 70 and 68%, respectively. These findings indicate that despite its high potential for removal of heavy metals from contaminated soils, bioleaching results in undesirable dissolution/loss of essential plant nutrients. This aspect warrants urgent attention and detailed studies to evaluate the appropriateness of the technique for field application.

  1. Changes in nutrient profile of soil subjected to bioleaching for removal of heavy metals using Acidithiobacillus thiooxidans. (United States)

    NareshKumar, R; Nagendran, R


    Studies were carried out to assess changes in nitrogen, phosphorus and potassium contents in soil during bioleaching of heavy metals from soil contaminated by tannery effluents. Indigenous sulfur oxidizing bacteria Acidithiobacillus thiooxidans isolated from the contaminated soil were used for bioremediation. Solubilization efficiency of chromium, cadmium, copper and zinc from soil was 88, 93, 92 and 97%, respectively. However, loss of nitrogen, phosphorus and potassium from the soil was 30, 70 and 68%, respectively. These findings indicate that despite its high potential for removal of heavy metals from contaminated soils, bioleaching results in undesirable dissolution/loss of essential plant nutrients. This aspect warrants urgent attention and detailed studies to evaluate the appropriateness of the technique for field application.

  2. Treatment of sludge containing nitro-aromatic compounds in reed-bed mesocosms - Water, BOD, carbon and nutrient removal. (United States)

    Gustavsson, L; Engwall, M


    Since the mid-1970s, Sweden has been depositing 1 million ton d.w sludge/year, produced at waste water treatment plants. Due to recent legislation this practice is no longer a viable method of waste management. It is necessary to improve existing and develop new sludge management techniques and one promising alternative is the dewatering and treatment of sludge in constructed wetlands. The aim of this study was to follow reduction of organic carbon, BOD and nutrients in an industrial sludge containing nitro-aromatic compounds passing through constructed small-scale wetlands, and to investigate any toxic effect such as growth inhibition of the common reed Phragmites australis. The result showed high reduction of all tested parameters in all the outgoing water samples, which shows that constructed wetlands are suitable for carbon and nutrient removal. The results also showed that P. australis is tolerant to xenobiotics and did not appear to be affected by the toxic compounds in the sludge. The sludge residual on the top of the beds contained low levels of organic carbon and is considered non-organic and could therefore be landfilled. Using this type of secondary treatment method, the amount of sludge could be reduced by 50-70%, mainly by dewatering and biodegradation of organic compounds.

  3. Control Structure Design of an Innovative Enhanced Biological Nutrient Recovery Activated Sludge System Coupled with a Photobioreactor

    DEFF Research Database (Denmark)

    Valverde Perez, Borja; Fuentes-Martínez, José Manuel; Flores Alsina, Xavier


    The TRENS system is a train of biological units designed for resource recovery from wastewater. It is a sequence of a modified enhanced biological phosphorus removal and recovery system (EBP2R) coupled with a photobioreactor (PBR). The bacteria-based system constructs an optimal culture media for...

  4. Particle size distribution and removal in the chemical-biological flocculation process

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhi-bin; ZHAO Jian-fu; XIA Si-qing; LIU Chang-qing; KANG Xing-sheng


    The particle characterization from the influent and effluent of a chemical-biological flocculation (CBF) process was studied with a laser diffraction device. Water samples from a chemically enhanced primary treatment (CEPT) process and a primary sediment tank process were also analyzed for comparison. The results showed that CBF process was not only effective for both the big size particles and small size particles removal, but also the best particle removal process in the three processes. The results also indicated that CBF process was superior to CEPT process in the heavy metals removal. The high and non-selective removal for heavy metals might be closely related to its strong ability to eliminate small particles. Samples from different locations in CBF reactors showed that small particles were easier to aggregate into big ones and those disrupted flocs could properly flocculate again along CBF reactor because of the biological flocculation.

  5. Removal of disinfection by-product formation potentials by biologically assisted GAC treatment

    Institute of Scientific and Technical Information of China (English)


    The object of this paper is to evaluate the removal of disinfection by-products formation potential by artificially intensified biological activated carbon(BAC) process which is developed on the basis of traditional ozone granular activated carbon (GAC). The results show that 23.1% of trihalomethane formation potential (THMFP) and 68% of haloacetic acid formation potential (HAAFP) can be removed by BAC,respectively. Under the same conditions, the removal rates of the same substances were 12.2% and 13-25 % respectively only by GAC process. Compared with GAC, the high removal rates of the two formed potential substances were due to the increasing of bioactivity of the media and the synergistic capabilities of biological degradation cooperating with activated carbon adsorption of organic compounds. BAC process has some advantages such as long backwashing cycle time, low backwashing intensity and prolonged activated carbon lifetime, etc.

  6. The contribution of 'omic'-based approaches to the study of enhanced biological phosphorus removal microbiology. (United States)

    Forbes, Christina M; O'Leary, Niall D; Dobson, Alan D; Marchesi, Julian R


    The role that microorganisms play in the biological removal of phosphate from wastewater streams has received sustained interest since its initial observation over 30 years ago. Recent advances in 'omic'-based approaches have greatly advanced our knowledge in this field and facilitated a refinement of existing enhanced biological phosphate removal (EBPR) models, which were primarily based on culture-dependent approaches that had predominantly been used to investigate the process. This minireview will focus on the recent advances made in our overall understanding of the EBPR process resulting from the use of 'omic'-based methodologies.

  7. Innovative low cost procedure for nutrient removal as an integrated element of a decentralised water management concept for rural areas. (United States)

    Burde, M; Rolf, F; Grabowski, F


    The absence of large rivers with rather high niveau of self purifying effect in parts of east Germany leads to a discharging of the effluent of wastewater treatment plants into the groundwater in many cases. One useful consequence is the idea of realisation of decentralised measures and concepts in urban water resources management concerning municipal wastewater as well as rainfall, precipitation. At the same time, only the upper soil zone--a few decimetres--is water--saturated and thus discharge effective, even when extreme rainfall takes place. Underneath, however, there generally exists an unsaturated soil zone, which is up to now a rather unexplored retardation element of the hydrologic- and substrate-cycle. Nutrient removal in small wastewater treatment plants that are emptying into ground waters is often beneficial. The presented studies optimised an inexpensive method of subsequent enhanced wastewater treatment. The developed reactor is similar to a concentrated subsoil passage. The fixed bed reactor is divided in two sections to achieve aerobic and anoxic conditions for nitrification/denitrification processes. To enhance phosphorus removal, ferrous particles are put into the aerobic zone. Two series of column tests were carried out and a technical pilot plant was built to verify the efficiency of the process. The results show that this method can be implemented successfully.

  8. A metagenome of a full-scale microbial community carrying out Enhanced Biological Phosphorus Removal

    DEFF Research Database (Denmark)

    Albertsen, Mads; Hansen, Lea Benedicte Skov; Saunders, Aaron Marc


    Enhanced biological phosphorus removal (EBPR) is widely used for removal of phosphorus from wastewater. In this study, a metagenome (18.2 Gb) was generated using Illumina sequencing from a full-scale EBPR plant to study the community structure and genetic potential. Quantitative fluorescence......, underlining the need for more reference genomes of key EBPR species. Only the genome of ‘Candidatus Accumulibacter’, a genus of phosphorus-removing organisms, was closely enough related to the species present in the metagenome to allow for detailed investigations. Accumulibacter accounted for only 4.8% of all...

  9. Combination of ion exchange system and biological reactors for simultaneous removal of ammonia and organics. (United States)

    Park, Wooshin; Jang, Eunhee; Lee, Myun-Joo; Yu, Seungho; Kim, Tak-Hyun


    A novel process for a simultaneous removal of ammonia and organics was developed on the basis of ion exchange and biological reactions. From batch experiments, it was found out that NH(4)(+) could be removed effectively by combining cation exchange and biological nitrification showing 0.98 mg N/m(2) ∙ s of a maximum flux. On the other hand, the removal of NO(3)(-) was 3.5 times faster than NH(4)(+) and the maximum flux was calculated to be 3.4 mg N/m(2) ∙ s. The systems for NH(4)(+) and NO(3)(-) removal were combined for establishing the IEBR process. When the process was operated in a continuous mode, approximately 95.8% of NH(4)(+) was removed showing an average flux of 0.22 mg N/m(2) · s. The removal efficiency of total nitrogen was calculated as 94.5% whereas that of organics was 99.5%. It was concluded that the IEBR process would be effectively used for a simultaneous removal of NH(4)(+) and organics.

  10. Embedding constructed wetland in sequencing batch reactor for enhancing nutrients removal: A comparative evaluation. (United States)

    Liu, Ranbin; Zhao, Yaqian; Zhao, Jinhui; Xu, Lei; Sibille, Caroline


    In the present study, a novel green bio-sorption reactor (GBR) was firstly proposed and preliminarily investigated by embedding constructed wetland (CW) into the aeration tank of the conventional activated sludge (CAS). This integrated novel system owns the striking features of adding carriers of wetland substrate (i.e. the dewatered alum sludge in this case) in CAS for robust phosphorus adsorption and enriching the biomass. Meanwhile, the "green" feature of this GBR imparted aesthetic value of CW to the CAS system. The preliminary 3-month trial of GBR based on a sequencing batch reactor (GB-SBR) with diluted piggery wastewater demonstrated an average removal of 96%, 99% and 90% for BOD, TP and TN, respectively. The comparison with moving bed biofilm reactor (MBBR) and integrated fixed-film activated sludge (IFAS) reflected the advantages of GBR over purification performance, aesthetic value and potential carbon sink. Moreover, the carriers used in the GBR are dewatered alum sludge which is in line with the policy of "recycle, reuse and reduce". Overall, this GBR undoubtedly offered a more sustainable and economical solution for retrofitting the aging CAS.

  11. Nitrate-reducing, sulfide-oxidizing bacteria as microbial oxidants for rapid biological sulfide removal. (United States)

    De Gusseme, Bart; De Schryver, Peter; De Cooman, Michaël; Verbeken, Kim; Boeckx, Pascal; Verstraete, Willy; Boon, Nico


    The emission of hydrogen sulfide into the atmosphere of sewer systems induces the biological production of sulfuric acid, causing severe concrete corrosion. As a possible preventive solution, a microbial consortium of nitrate-reducing, sulfide-oxidizing bacteria (NR-SOB) was enriched in a continuously stirred tank reactor in order to develop a biological technique for the removal of dissolved sulfide. The consortium, dominated by Arcobacter sp., was capable of removing 99% of sulfide. Stable isotope fractioning of the sulfide indicated that the oxidation was a biological process. The capacity of the NR-SOB consortium for rapid removal of sulfide was demonstrated by using it as an inoculum in synthetic and real sewage. Removal rates up to 52 mg sulfide-S g VSS(-1) h(-1) were achieved, to our knowledge the highest removal rate reported so far for freshwater species in the absence of molecular oxygen. Further long-term incubation experiments revealed the capacity of the bacteria to oxidize sulfide without the presence of nitrate, suggesting that an oxidized redox reserve is present in the culture.

  12. Recent developments in the biochemistry and ecology of enhanced biological phosphorus removal

    NARCIS (Netherlands)

    Kortstee, GJJ; Appeldoorn, KJ; Bonting, CFC; van Niel, EWJ; van Veen, HW


    Most of the genes encoding the enzymes involved in polyP synthesis and degradation and in phosphate transport have been studied in various Gram-negative bacteria. Progress has also been made in studying the biochemical mechanisms underlying the process of enhanced biological phosphorus removal (EBPR

  13. Isolation and characterization of Cupriavidus basilensis HMF14 for biological removal of inhibitors from lignocellulosic hydrolysatembt

    NARCIS (Netherlands)

    Wierckx, N.; Koopman, F.; Bandounas, L.; Winde,; Ruijssenaars, H.J.


    The formation of toxic fermentation inhibitors such as furfural and 5-hydroxy-2-methylfurfural (HMF) during acid (pre-)treatment of lignocellulose, calls for the efficient removal of these compounds. Lignocellulosic hydrolysates can be efficiently detoxified biologically with microorganisms that spe

  14. A hypothesis on Microthrix parvicella proliferation in biological nutrient removal activated sludge systems with selector tanks. (United States)

    Noutsopoulos, Constantinos; Mamais, Daniel; Andreadakis, Andreas; Stams, Alfons


    The objective of this study was to evaluate the ability of Microthrix parvicella for long-chain fatty acids uptake under anaerobic, anoxic, and aerobic conditions as well as its ability to utilize volatile fatty acids and long-chain fatty acids under anoxic and aerobic conditions. According to the results, a hypothesis on the competition between floc-forming microorganisms and M. parvicella for long-chain fatty acids uptake under aerobic, anoxic, and anaerobic conditions was formulated. According to this hypothesis, M. parvicella exhibits similar long-chain fatty acids uptake capacity with floc-forming microorganisms even at relatively high floc loading values that are very often imposed at selector tanks. Following this hypothesis, the failure of selector tanks to provide for an effective M. parvicella control is evidenced. Based on the experimental results, the ability of M. parvicella to utilize long-chain fatty acids with rates comparable to those of floc formers, even in anoxic conditions, in conjunction with its lower acetate utilization rates, provides a good explanation regarding its preference to slowly biodegradable organic carbon compounds.

  15. Enhanced Biological Phosphorus Removal with Pseudomonas putida GM6 from Activated Sludge

    Institute of Scientific and Technical Information of China (English)


    The enhanced biological phosphorus removal (EBPR) method is widely adopted for phosphorus removal from wastewater, yet little is known about its microbiological and molecular mechanisms. Therefore, it is difficult to predict and control the deterioration of the EBPR process in a large-scale municipal sewage treatment plant. This study used a novel strain isolated in the laboratory, Pseudomonas putida GM6, which had a high phosphate accumulating ability and could recover rapidly from the deteriorated system and enhance the capability of phosphorus removal in activated sludge. Strain GM6 marked with gfp gene, which was called GMTR, was delivered into a bench-scale sequencing batch reactor (SBR)of low efficiency, to investigate the colonization of GMTR and removal of phosphorus. After 21 days, the proportion of GMTR in the total bacteria of the sludge reached 9.2%, whereas the phosphorus removal rate was 96%, with an effluent concentration of about 0.2 mg L-1. In the reactor with the addition of GMTR, phosphorus was removed quickly, in 1 h under anaerobic conditions, and in 2 h under aerobic conditions. These evidences were characteristic of EBPR processes.Field testing was conducted at a hospital sewage treatment facility with low phosphorus removal capability. Twentyone days after Pseudononas putida GM6 was added, effluent phosphorus concentration remained around 0.3 mg L-1,corresponding to a removal rate of 96.8%. It was therefore demonstrated that Pseudomonas putida GM6 could be used for a quick startup and enhancement of wastewater biological phosphorus removal, which provided a scientific basis for potential large-scale engineering application.

  16. Characterization of nutrient removal and microalgal biomass production on an industrial waste-stream by application of the deceleration-stat technique

    DEFF Research Database (Denmark)

    Van Wagenen, Jonathan; Pape, Mathias Leon; Angelidaki, Irini


    in batch and continuous cultures. The aim was to evaluate the rates of nutrient removal and biomass production possible at various dilution rates. The results demonstrate that the industrial wastewater served as a highly effective microalgae culture medium and that dilution rate strongly influenced algae...

  17. Biological N removal from wastes generated from amine-based CO2 capture: case monoethanolamine. (United States)

    Hauser, Ingrid; Colaço, Ana B; Skjæran, Julie A; Einbu, Aslak; Ostgaard, Kjetill; Svendsen, Hallvard F; Cervantes, Francisco J


    Large-scale amine-based CO(2) capture will generate waste containing large amounts of ammonia, in addition to contaminants such as the actual amine as well as degradation products thereof. Monoethanolamine (MEA) has been a dominant amine applied so far in this context. This study reveals how biological N removal can be achieved even in systems heavily contaminated by MEA in post- as well as pre-denitrification treatment systems, elucidating the rate-limiting factors of nitrification as well as aerobic and denitrifying biodegradation of MEA. The hydrolysis of MEA to ammonia readily occurred both in post- and pre-denitrification treatment systems with a hydraulic retention time of 7 h. MEA removal was ≥99 ± 1 % and total nitrogen removal 77 ± 10 % in both treatment systems. This study clearly demonstrates the advantage of pre-denitrification over post-denitrification for achieving biological nitrogen removal from MEA-contaminated effluents. Besides the removal of MEA, the removal efficiency of total nitrogen as well as organic matter was high without additional carbon source supplied.

  18. Removal of disinfection by-products formation potential by biologically intensified process

    Institute of Scientific and Technical Information of China (English)

    AN Dong; LI Wei-guang; CUI Fu-yi; HE Xin; ZHANG Jin-song


    The removal of disinfection by-products formation potential(DBPFP) in artificially intensified biological activated carbon(IBAC) process which is developed on the basis of traditional ozone granular activated carbon was evaluated. By IBAC removals of 31% and 68% for THMFP and HAAFP were obtained respectively. Under identical conditions, the removals of the same substances were 4% and 32% respectively only by the granular activated carbon(GAC) process. Compared with GAC, the high removal rates of the two formed potential substances were due to the increasing of bioactivity of the media and the synergistic capabilities of biological degradation cooperating with activated carbon adsorption of organic compounds. A clear linear correlation ( R2 = 0.9562 and R2 = 0.9007) between DOC HAAFP removal rate and Empty Bed Contact Time(EBCT) of IBAC process was observed, while that between THMFP removal rate and EBCT of GAC was R2 = 0.9782. In addition certain linear correlations between THMFP, HAAFP and UV254 ( R2 = 0.855 and R2 = 0.7702) were found for the treated water. For IBAC process there are also more advantages such as long backwashing cycle time, low backwashing intensity and prolonging activated carbon lifetime and so on.

  19. Biological nitrogen fixation and nutrient release from litter of the guachapele leguminous tree under pure and mixed plantation with eucalyptus.


    Fabiano de Carvalho Balieiro; Bruno José Rodrigues Alves; Marcos Gervásio Pereira; Sérgio Miana de Faria; Avílio Antônio Franco; Campello,Eduardo F.C.


    Pseudosamanea guachapele (guachapele), a nitrogen fixing leguminous tree, is an alternative for mixed forest plantations in the tropics. As little information is available for guachapele (Mimosoideae) in mixed plantation with eucalyptus considering the Brazilian edaphoclimatic conditions, an experiment was carried out to evaluate the contribution of biological nitrogen fixation to guachapele and leaf litter decomposition rates and nutrient release of eucalyptus and guachapele residues (pure a...

  20. Removing undesirable color and boosting biological activity in red beet extracts using gamma irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seung Sik; Lee, Eun Mi; Hong, Sung Hyun; Bai, Hyoung Woo; Chung, Byung Yeoup [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Lee, In Chul [Youngdong University, Youngdong (Korea, Republic of)


    Red beet (Beta vulgaris L.) is a traditional and popular vegetable distributed in many part of the world and has been used as a natural colorant in many dairy products, beverages, candies and cattle products. Red beet roots contain two groups of betalain pigments, redviolet betacyanins and yellow betaxanthins. Betalains possess several biological activities such as antioxidant, anti-inflammatory, hepatoprotective, and anticancer properities. Recent trend of using natural products in industries tends toward multifunctional, high quality, and highpriced value foods and cosmetics. To meet the needs of consumers, cosmetics, medicine, and foods should contain the proper amount of natural products. Although the color removal processes such as filtration and absorption by clay are still useful, these procedures are difficult, time-consuming and costly. To overcome this problem, the radiation technology has emerged as a new way. Radiation technology has been applied to the decomposition and decoloration of pigment and is an efficient technique for inactivating pathogens, removing undesirable color in biomaterial extracts and improving or maintaining biological activities. Gamma-irradiation and electron beamirradiation techniques in previous reports were applied in order to remove any undesirable color and to improve or maintain biological activities of various extracts such as green tea leaves, licorice root, and S. chinensis fruits. Latorre et al. reported that betacyanin concentration decreased with the irradiation dose and significantly, in 35%, after 2.0 kGy of gamma-ray, whereas betaxathin concentration increased (about 11%-ratio with respect to control) after 1 kGy but decreased (about 19%) after 2 kGy. However, they did not try to analysis for completed removal of red beet pigments. Therefore, it is necessary to find the optimum irradiation dose for entirely removing red pigments in red beet. The aim of this work was to address the effects of the color removal and

  1. Removing Iron and Manganese Simultaneously from Ground Water Using One-stage Biological Filter

    Institute of Scientific and Technical Information of China (English)

    XUE Gang; GAO Pin; GONG Qing-jie


    A novel process for removing iron and manganese simultaneously in ground water, which consisted of simple aeration and one-stage filtration, was developed in this research. It was found that the biological process had much higher manganese removal efficiency than chemical contact oxidation process. At the same time, the optimal operation parameters of aeration and biological filtration such as DO concentration and pH after aeration, filtration rate before and after startup, filtration operation cycle and backwashing rate, etc., were also obtained by experiments. By analyzing water quafity in different positions of filter bed, it was found that the oxidation of Fe2+ in biological filter bed adapted to first-order reaction, whereas the oxidation of Mn2+ conformed to zero-order reaction, which could be explained by Michaelis-Menten enzyme reaction equation when substrate concentration was far more than bacteria amount.

  2. Effects of photoperiod on nutrient removal, biomass production, and algal-bacterial population dynamics in lab-scale photobioreactors treating municipal wastewater. (United States)

    Lee, Chang Soo; Lee, Sang-Ah; Ko, So-Ra; Oh, Hee-Mock; Ahn, Chi-Yong


    Effects of photoperiod were investigated in lab-scale photobioreactors containing algal-bacterial consortia to reduce organic nutrients from municipal wastewater. Under three photoperiod conditions (12 h:12 h, 36 h:12 h, and 60 h:12 h dark–light cycles), nutrient removals and biomass productions were measured along with monitoring microbial population dynamics. After a batch operation for 12 days, 59–80% carbon, 35–88% nitrogen, and 43–89% phosphorus were removed from influents, respectively. In this study, carbon removal was related positively to the length of dark cycles, while nitrogen and phosphorus removals inversely. On the contrast, the highest microbial biomass in terms of chlorophyll a, dry cell weight, and algal/bacterial rRNA gene markers was produced under the 12 h:12 h dark–light cycle among the three photoperiods. The results showed 1) simultaneous growths between algae and bacteria in the microbial consortia and 2) efficient nitrogen and phosphorus removals along with high microbial biomass production under prolonged light conditions. Statistical analyses indicated that carbon removal was significantly related to the ratio of bacteria to algae in the microbial consortia along with prolonged dark conditions (p < 0.05). In addition, the ratio of nitrogen removal to phosphorus removal decreased significantly under prolonged dark conditions (p < 0.001). These results indicated that the photoperiod condition has remarkable impacts on adjusting nutrient removal, producing microbial biomass, and altering algal-bacterial population dynamics. Therefore, the control of photoperiod was suggested as an important operating parameter in the algal wastewater treatment.

  3. Removal Characteristics of Organic Pollutants from Eutrophic Raw Water by Biological Pretreatment Reactors

    Directory of Open Access Journals (Sweden)

    Guangcan Zhu


    Full Text Available Two biological contact oxidation reactors, cascade biofilm reactor (CSBR and one-step biofilm reactor (OSBR, were used in this paper for pretreatment of eutrophic water from Lake Taihu in China. The CSBR was more effective and stable for eutrophic water treatment than OSBR, in terms of extracellular microcystin-LR, chlorophyll-a, DOC, and biodegradable dissolved organic carbon (BDOC removal. Removal efficiencies of extracellular microcystin-LR and chlorophyll-a were 75.8% and 59.7% in CSBR and 60.5% and 53.0% after 2 h in OSBR. CSBR had much higher removal efficiency (34.3% than OSBR (22.7% for DOC, and CSBR could remove 67% BDOC, accounting for 34% of total DOC in source water. 11.5% of DOC was removed through means other than biological degradation, such as biofilm adsorption and bioflocculation. In CSBR at 5.5~13°C, 57.5% of atrazine was removed at 2 h hydraulic retention time, with background concentration of 136.5 ng/L. Meanwhile, removal efficiencies of three phthalic acid esters (PAEs (dimethyl phthalate, di-(2-ethylhexyl phthalate, and di-n-butyl phthalate were 78.7%, 52.4%, and 85.3%, respectively. Only 35.2% of polycyclic aromatic hydrocarbons (PAHs could be removed by CSBR with initial concentration of 21.5 μg/L. The results indicated that CSBR is effective in low-molecular-weight organic pollution pretreatment and provides benefits in terms of effluent quality.

  4. Impact of hazardous events on the removal of nutrients and trace organic contaminants by an anoxic-aerobic membrane bioreactor receiving real wastewater. (United States)

    Phan, Hop V; Hai, Faisal I; McDonald, James A; Khan, Stuart J; van de Merwe, Jason P; Leusch, Frederic D L; Zhang, Ren; Price, William E; Broeckmann, Andreas; Nghiem, Long D


    The impacts of four simulated hazardous events, namely, aeration failure, power loss, and chemical shocks (ammonia or bleach) on the performance of an anoxic-aerobic membrane bioreactor (MBR) receiving real wastewater were investigated. Hazardous events could alter pH and/or oxidation reduction potential of the mixed liquor and inhibit biomass growth, thus affecting the removal of bulk organics, nutrients and trace organic contaminants (TrOC). Chemical shocks generally exerted greater impact on MBR performance than aeration/power failure events, with ammonia shock exerting the greatest impact. Compared to total organic carbon, nutrient removal was more severely affected. Removal of the hydrophilic TrOCs that are resistant and/or occur at high concentrations in wastewater was notably affected. The MBR effectively reduced estrogenicity and toxicity from wastewater, but chemical shocks could temporarily increase the endocrine activity of the effluent. Depending on the chemical shock-dose and the membrane flux, hazardous events can exacerbate membrane fouling.

  5. Biological Removal of Phosphate Using Phosphate Solubilizing Bacterial Consortium from Synthetic Wastewater: A Laboratory Scale

    Directory of Open Access Journals (Sweden)

    Dipak Paul


    Full Text Available Biological phosphate removal is an important process having gained worldwide attention and widely used for removing phosphorus from wastewater. The present investigation was aimed to screen the efficient phosphate solubilizing bacterial isolates and used to remove phosphate from synthetic wastewater under shaking flasks conditions. Pseudomonas sp. JPSB12, Enterobacter sp. TPSB20, Flavobacterium sp. TPSB23 and mixed bacterial consortium (Pseudomonas sp. JPSB12+Enterobacter sp. TPSB20+Flavobacterium sp. TPSB23 were used for the removal of phosphate. Among the individual strains, Enterobacter sp. TPSB20 was removed maximum phosphate (61.75% from synthetic wastewater in presence of glucose as a carbon source. The consortium was effectively removed phosphate (74.15-82.50% in the synthetic wastewater when compared to individual strains. The pH changes in culture medium with time and extracellular phosphatase activity (acid and alkaline were also investigated. The efficient removal of phosphate by the consortium may be due to the synergistic activity among the individual strains and phosphatase enzyme activity. The use of bacterial consortium in the remediation of phosphate contaminated aquatic environments has been discussed.

  6. Biological groundwater treatment for chromium removal at low hexavalent chromium concentrations. (United States)

    Mamais, Daniel; Noutsopoulos, Constantinos; Kavallari, Ioanna; Nyktari, Eleni; Kaldis, Apostolos; Panousi, Eleni; Nikitopoulos, George; Antoniou, Kornilia; Nasioka, Maria


    The objective of this work is to develop and evaluate biological groundwater treatment systems that will achieve hexavalent chromium reduction and total chromium removal from groundwater at hexavalent chromium (Cr(VI)) groundwater concentrations in the 0-200 μg/L range. Three lab-scale units operated, as sequencing batch reactors (SBR) under aerobic, anaerobic and anaerobic-aerobic conditions. All systems received groundwater with a Cr(VI) content of 200 μg/L. In order to support biological growth, groundwater was supplemented with milk, liquid cheese whey or a mixture of sugar and milk to achieve a COD concentration of 200 mg/L. The results demonstrate that a fully anaerobic system or an anaerobic-aerobic system dosed with simple or complex external organic carbon sources can lead to practically complete Cr(VI) reduction to Cr(III). The temperature dependency of maximum Cr(VI) removal rates can be described by the Arrhenius relationship. Total chromium removal in the biological treatment systems was not complete because a significant portion of Cr(III) remained in solution. An integrated system comprising of an anaerobic SBR followed by a sand filter achieved more than 95% total chromium removal thus resulting in average effluent total and dissolved chromium concentrations of 7 μg/L and 3 μg/L, respectively.

  7. [Determination of the biological activity of aminoglycoside antibiotics on a dry nutrient medium of Soviet manufacture]. (United States)

    Grigor'eva, V M; Andreeva, Z M; Astanina, L N; Shiriaeva, V L; Gridneva, N I


    Possible use of the dry nutrient medium manufactured in the USSR for the assay of aminoglycoside antibiotic activity with the agar diffusion method was studied. The optimal conditions for the antibiotic activity assay on this medium were developed. The dry nutrient medium may be used for the activity assay of the aminoglycoside antibiotics, i. e. streptomycin sulfate, dihydrostreptomycin sulfate, neomycin sulfate, monomycin and gentamicin sulfate.

  8. Removal of anaerobic soluble microbial products in a biological activated carbon reactor. (United States)

    Dong, Xiaojing; Zhou, Weili; He, Shengbing


    The soluble microbial products (SMP) in the biological treatment effluent are generally of great amount and are poorly biodegradable. Focusing on the biodegradation of anaerobic SMP, the biological activated carbon (BAC) was introduced into the anaerobic system. The experiments were conducted in two identical lab-scale up-flow anaerobic sludge blanket (UASB) reactors. The high strength organics were degraded in the first UASB reactor (UASB1) and the second UASB (UASB2, i.e., BAC) functioned as a polishing step to remove SMP produced in UASB1. The results showed that 90% of the SMP could be removed before granular activated carbon was saturated. After the saturation, the SMP removal decreased to 60% on the average. Analysis of granular activated carbon adsorption revealed that the main role of SMP removal in BAC reactor was biodegradation. A strain of SMP-degrading bacteria, which was found highly similar to Klebsiella sp., was isolated, enriched and inoculated back to the BAC reactor. When the influent chemical oxygen demand (COD) was 10,000 mg/L and the organic loading rate achieved 10 kg COD/(m3 x day), the effluent from the BAC reactor could meet the discharge standard without further treatment. Anaerobic BAC reactor inoculated with the isolated Klebsiella was proved to be an effective, cheap and easy technical treatment approach for the removal of SMP in the treatment of easily-degradable wastewater with COD lower than 10,000 mg/L.

  9. Effect of continuous addition of an organic substrate to the anoxic phase on biological phosphorus removal

    DEFF Research Database (Denmark)

    Meinhold, Jens; Pedersen, Heinz; Arnold, Eva


    The continuous introduction of a biological phosphorus removal (BPR) promoting organic substrate to the denitrifying reactor of a BPR process is examined through a series of batch experiments using acetate as model organic substrate. Several observations are made regarding the influence...... while a net P-release occurs. Whether the introduction of BPR promoting organic substrates to the denitrifying reactor is detrimental to overall P-removal appears to be dependent on the interaction between aerobic P-uptake, which is a function of PHB level, and the aerobic residence time. (C) 1998...

  10. Seasonal and interannual variability of physical and biological dynamics at the shelfbreak front of the Middle Atlantic Bight: nutrient supply mechanisms

    Directory of Open Access Journals (Sweden)

    R. He


    Full Text Available A high-resolution, 3-dimensional coupled biophysical model is used to simulate ocean circulation and ecosystem variations at the shelfbreak front of the Middle Atlantic Bight (MAB. Favorable comparisons between satellite observations and model hindcast solutions from January 2004 to November 2007 indicate the model has intrinsic skills in resolving fundamental physical and biological dynamics at the MAB shelfbreak. Seasonal and interannual variability of ocean physical and biological states and their driving mechanisms are further analyzed. The domain-wide upper water column nutrient content is found to peak in late winter-early spring. Phytoplankton spring bloom starts 1–2 months later, followed by zooplankton bloom in early summer. Our analysis shows the variability of shelfbreak nutrient supply is controlled by local mixing that deepens the mixed layer and injects deep ocean nutrients into the upper water column and alongshore nutrient transport by the shelfbreak jet and associated currents. Nutrient vertical advection associated with the shelfbreak bottom boundary layer convergence is another significant contributor. Spring mean nutrient budget diagnostics along the Nantucket transect are compared between nutrient rich 2004 and nutrient poor 2007. Physical advection and diffusion play the major role in determining strong interannual variations in shelfbreak nutrient content. The biological (source minus sink term is very similar between these two years.

  11. Micropollutant removal during biological wastewater treatment and a subsequent ozonation step

    Energy Technology Data Exchange (ETDEWEB)

    Schaar, Heidemarie, E-mail: [Institute of Water Quality, Resources and Waste Management, Vienna University of Technology, Karlsplatz 13/226, 1040 Vienna (Austria); Clara, Manfred; Gans, Oliver [Umweltbundesamt, Spittelauer Lande 5, 1090 Vienna (Austria); Kreuzinger, Norbert [Institute of Water Quality, Resources and Waste Management, Vienna University of Technology, Karlsplatz 13/226, 1040 Vienna (Austria)


    The design criteria for wastewater treatment plants (WWTP) and the sludge retention time, respectively, have a significant impact on micropollutant removal. The upgrade of an Austrian municipal WWTP to nitrogen removal (best available technology, BAT) resulted in increased elimination of most of the analyzed micropollutants. Substances, such as bisphenol-A, 17alpha-ethinylestradiol and the antibiotics erythromycin and roxithromycin were only removed after the upgrade of the WWTP. Nevertheless, the BAT was not sufficient to completely eliminate these compounds. Thus, a pilot scale ozonation plant was installed for additional treatment of the effluent. The application of 0.6 g O{sub 3} g DOC{sup -1} increased the removal of most of the micropollutants, especially for compounds that were not degraded in the previous biological process, as for example carbamazepine and diclofenac. These results indicated that the ozonation of WWTP effluent is a promising technology to further decrease emissions of micropollutants from the treatment process. - SRT is an important criterion for micropollutant removal in wastewater treatment and the application of ozone is suitable for further removal of micropollutants.

  12. Internal carbon source from sludge pretreated by microwave-H2O2 for nutrient removal in A2/O-membrane bioreactors. (United States)

    Xu, Rongle; Zhang, Qing; Tong, Juan; Wei, Yuansong; Fan, Yaobo


    To improve the nutrient removal, the feasibility was studied for the organics released from sludge pretreated by microwave-H2O2 process (MHP) to be used as internal carbon source in two A2/O-membrane bioreactors (MBRs). The experiments were conducted for the nutrient removal and the membrane fouling. The results showed that the removal efficiencies of TN and TP were improved by 11% and 28.34%, respectively, as C/N ratio was adjusted to 8 by adding the internal carbon source, and the ratio of soluble chemical oxygen demand (sCOD) consumed easily for denitrification was about 46% of the total sCOD in the internal carbon source. The addition of the internal carbon sources did not lead to severe membrane fouling in the experimental A2/O-MBR. It is implied that the organics released from sludge pretreated by MHP could be used as the internal carbon source to enhance the nutrient removal in A2/O-MBRs.

  13. Phosphate limitation in biological rapid sand filters used to remove ammonium from drinking water

    DEFF Research Database (Denmark)

    Lee, Carson Odell; Albrechtsen, Hans-Jørgen; Smets, Barth F.;


    Removing ammonium from drinking water is important for maintaining biological stability in distribution systems. This is especially important in regions that do not use disinfectants in the treatment process or keep a disinfectant residual in the distribution system. Problems with nitrification c...... the total number of ammonium oxidizing bacteria in the column. © 2013 American Water Works Association AWWA WQTC Conference Proceedings All Rights Reserved....

  14. Using metagenomics and metatranscriptomics to study specific bacterial species involved in biological phosphorus removal from wastewater

    DEFF Research Database (Denmark)

    Albertsen, Mads; McIlroy, Simon Jon; Stokholm-Bjerregaard, Mikkel

    profiles by metatranscriptomics. To demonstrate this we revisited the bacteria involved in enhanced biological phosphorus removal (EBPR) from wastewater treatment plants. The EBPR process is used all over the world, has a large body of information regarding the underlying microbiology, and is often studied...... to enrich for bacteria contributing to phosphorus removal and their normal competitors. To extract complete genomes we generated two metagenomes from each reactor, taken approximately 1 month apart, using the Illumina HiSeq2000 platform. Due to low micro-diversity in the reactors (2-15 dominating species...... phosphorus removal process in the treatment plant, sampling every 20 min during the 9 hour experiment. Metratranscriptome data was generated from selected samples using the stranded RNAseq Illumina protocol. We were able to extract genomes from the model polyphosphate accumulating organism (PAO) Ca...

  15. Nitrogen and Phosphorus Removal Performance in the Novel Multi-Layered Biological Tricking Filter

    Directory of Open Access Journals (Sweden)

    CUI Ting-ting


    Full Text Available Biological trickling filter is one of the main rural sewage treatment technology, but it still has the shortcomings such as lower re-moval efficiency for nitrogen and phosphorus or lower stability. In order to improve the nitrogen and phosphorus removal efficiency of the de-vice and find out its optimum technological conditions, the study took the novel multi-layered biological tricking filter as the device to test the contribution of filter medium, hydraulic loading, recirculation ratio on the treatment of nitrogen and phosphorus removal. The results showed that when the hydraulic loading of 4 m3·m-2·d-1, the recirculation ratio rate of 2∶1 and slag as filter medium were applied, the best effect could be achieved in the filter. The highest mean efficiency of NH4+-N, TN, TP and COD were 87.08%, 57.37%, 66.04% and 80.78%, respectively.The results also indicated that higher recirculation ratio was one of effective paths to improve nitrogen removal efficiency.

  16. Effects of Litter Removal and Addition on the Nutrient Mineralization Dynamics in Hyperseasonal Tropical Savannas of the Brazilian Pantanal (United States)

    Hentz, C. S.; Pinto-Jr, O. B.; Vourlitis, G. L.


    The tropical savanna of Brazil (cerrado) is extremely species diverse and it encompasses many different physiognomic features, which are influenced by rainfall, fire, and soil nutrient availability. Plant litter decomposition recycles nutrients to the soil, and in turn, assists plant growth. However the rate at which these nutrients become available to the soil is poorly understood. Thus, a six month field experiment that encompassed the wet and dry seasons was conducted to assess how different quantities of litter inputs affect nutrient (P, N, C, K, Ca, and Mg) availability. It was hypothesized that nutrient mineralization would be significantly influenced by manipulation of the surface litter and that there would be a positive correlation between soil moisture and nutrient mineralization. Initial results indicate that there were significant differences in mineralization over time for all nutrients, except P, supporting our hypothesis of changes in mineralization with soil moisture. However, there were no significant differences between litter treatments and net mineralization rates for all the nutrients tested. Our results indicate that litterpool size has little effect on short-term nutrient mineralization dynamics.

  17. Population dynamics of filamentous bacteria identified in Polish full-scale wastewater treatment plants with nutrients removal. (United States)

    Miłobędzka, A; Muszyński, A


    A comprehensive study of the identity and population dynamics of filamentous bacteria in five Polish full-scale municipal wastewater treatment plants (WWTPs) with nutrients removal had been carried out for 2 years. A quantitative culture-independent, molecular method - fluorescence in situ hybridization - was applied to evaluate the structure of different filamentous bacteria populations and their temporal variations. Activated sludge was examined for the abundance of 11 groups of filamentous bacteria. On average, filaments constituted 28% of all bacteria. All samples presented a low diversity of probe-defined filamentous bacteria, usually with significant domination of Chloroflexi (with distinction to types 1851, 0803 and others) and/or Microthrix (14% and 7% of EUBmix, respectively). Haliscomenobacter hydrossis, Mycolata, Skermania piniformis and TM7 were less abundant, whereas Curvibacter, Thiothrix/021N and family Gordonia have not been detected in any of the samples. The tested WWTPs showed similarity among species found and differences in their abundance. The composition of filamentous populations was rather stable in each plant and similar to those found in other European countries. Little differences between plants were shown by multivariate analysis of variance in terms of Chloroflexi and Microthrix. No significant general correlations have been found with Pearson product-moment correlation coefficient and Spearman's rank correlation coefficient. Medium correlation strength between the presence of different filaments was recorded only for Microthrix and Skermania piniformis. Deleterious effect on settling properties of sludge (measured as sludge volume index) was found only for abundance of Microthrix; a strong linear correlation was recorded between them. However, no other correlations with wastewater and operational data were revealed.

  18. The Denitrifying Biological Phosphorus Removal Performance in Anaerobic/Anoxic Sequencing Batch Reactor: The Effect of Carbon Source


    Gürtekin, Engin; ŞEKERDAĞ, Nusret


    In this study, the effect of carbon source on denitrifying biological phosphorus removal performance in acetate and glucose fed two anaerobic/anoxic sequencinq batch reactor (SBR) was investigated. Glucose and acetate were used as the substrates. In acetate and glucose fed reactors, the COD (Chemical Oxygen Demand) removal efficiencies were 91,90% and PO4-P removal efficiencies were 87,51% respectively. These results shows that the phosphorus removal efficiency is lower in glucose fed reactor.

  19. Mussels as a tool for mitigation of nutrients in the marine environment

    DEFF Research Database (Denmark)

    Petersen, Jens Kjerulf; Hasler, Berit; Timmermann, Karen;


    Long-line mussel farming has been proposed as a mitigation tool for removal of excess nutrients in eutrophic coastal waters. A full-scale mussel farm optimized for cost efficient nutrient removal was established in the eutrophic Skive Fjord, Denmark where biological and economic parameters related...

  20. Two-phase photoperiodic cultivation of algal-bacterial consortia for high biomass production and efficient nutrient removal from municipal wastewater. (United States)

    Lee, Chang Soo; Oh, Hyung-Seok; Oh, Hee-Mock; Kim, Hee-Sik; Ahn, Chi-Yong


    This study investigated the photoperiodic effects on the biomass production and nutrient removal in the algal-bacterial wastewater treatment, under the following three conditions: (1) a natural 12h:12h LD cycle, (2) a dark-elongated 12h:60h LD cycle, and (3) a two-phase photoperiodic 12h:60h LD, followed by 12h:12h LD cycles. The two-phase photoperiodic operation showed the highest dry cell weight and lipid productivity (282.6mgL(-1)day(-1), 71.4mgL(-1)day(-1)) and most efficient nutrient removals (92.3% COD, 95.8% TN, 98.1% TP). The genetic markers and sequencing analyses indicated rapid increments of bacteria, subsequent growths of Scenedesmus, and stabilized population balances between algae and bacteria. In addition, the two-phase photoperiod provided a higher potential for the algal-bacterial consortia to utilize various organic carbon substrates.

  1. Influence of SiO2 and graphene oxide nanoparticles on efficiency of biological removal process. (United States)

    Esmaeili-Faraj, Seyyed Hamid; Nasr Esfahany, Mohsen


    The effects of the presence of synthesized silica (SS) and exfoliated graphene oxide (EGO) on the removal of sulfide ion with activated sludge (AS) are experimentally investigated. The maximum removal efficiency of sulfide ion for AS without nanoparticles, and the samples with SS and EGO nanoparticles were 81%, 88% and 79%, respectively. Moreover, the maximum elimination capacity (ECmax) for the bioreactor with SS-nanoparticles is 7542 mg/L s, while the ECmax of AS and EGO samples were 7075 and 6625 mg/L s, respectively. Two filamentous microbial strains as Gram-negative and Gram-positive bacteria are discerned that removed sulfide ion in the presence of nanoparticles. The measurement of mixture liquor volatile suspended solid that indicates the biomass growth rate during the test shows that the bioreactor containing SS-nanoparticles has more biomass content than the other samples. Our findings indicate that SS-nanoparticles with 0.1% wt. concentration in the bioreactor have no negative effects on the efficiency of the biological removal of sulfide and the presence of SS-nanoparticles even enhances the performance of the bioreactor. On the other side, a bioreactor with EGO nanosheets, as highly antibacterial nanoparticles, with 0.02% wt. concentration significantly influences the microbial growth and reduces sulfide removal efficiency.

  2. The oxidation of As(III) in groundwater using biological manganese removal filtration columns. (United States)

    Yang, Hong; Sun, Wenyong; Ge, Huoqing; Yao, Renda


    Arsenic is known as a toxic element to humans, and has been reported to co-exist with iron and manganese in groundwater worldwide. The typical method for arsenic removal from groundwater is to oxidize trivalent (As(III)) to pentavalent (As(V)) followed by the As(V) removal. This study aims to evaluate the oxidization efficiency of As(III) in a mature biological manganese (Mn(2+)) removal filtration system with different elevated influent As(III) concentrations. The effects of influent Mn(2+) concentrations, influent As(III) concentrations, filtration rates and dissolved oxygen (DO) levels on the efficiency of As(III) oxidation were assessed. The results showed that As(III) oxidation can be simultaneously achieved with removing Mn(2+) in the filtration system. The oxidation efficiency was not impacted by increasing the influent As(III) concentration up to nearly 2500 µg L(-1), but the filtration rate was limited at 11 m h(-1) for maintaining the effluent As(III) concentration below 10 µg L(-1). The oxidation process followed first-order kinetics with the constant reaching 0.56-0.61 min(-1). The As(III) oxidation process was most likely to be mediated by the bacterial community initially developed for Mn(2+) removal in the filtration system, which performed the catalytic oxidation for As(III).

  3. Maximum removal rate of propionic acid as a sole carbon source in UASB reactors and the importance of the macro- and micro-nutrients stimulation. (United States)

    Ma, Jingxing; Mungoni, Lucy Jubeki; Verstraete, Willy; Carballa, Marta


    The maximum propionic acid (HPr) removal rate (R(HPr)) was investigated in two lab-scale Upflow Anaerobic Sludge Bed (UASB) reactors. Two feeding strategies were applied by modifying the hydraulic retention time (HRT) in the UASB(HRT) and the influent HPr concentration in the UASB(HPr), respectively. The experiment was divided into three main phases: phase 1, influent with only HPr; phase 2, HPr with macro-nutrients supplementation and phase 3, HPr with macro- and micro-nutrients supplementation. During phase 1, the maximum R(HPr) achieved was less than 3 g HPr-CODL(-1)d(-1) in both reactors. However, the subsequent supplementation of macro- and micro-nutrients during phases 2 and 3 allowed to increase the R(HPr) up to 18.1 and 32.8 g HPr-CODL(-1)d(-1), respectively, corresponding with an HRT of 0.5h in the UASB(HRT) and an influent HPr concentration of 10.5 g HPr-CODL(-1) in the UASB(HPr). Therefore, the high operational capacity of these reactor systems, specifically converting HPr with high throughput and high influent HPr level, was demonstrated. Moreover, the presence of macro- and micro-nutrients is clearly essential for stable and high HPr removal in anaerobic digestion.

  4. Comparison of quartz sand, anthracite, shale and biological ceramsite for adsorptive removal of phosphorus from aqueous solution. (United States)

    Jiang, Cheng; Jia, Liyue; Zhang, Bo; He, Yiliang; Kirumba, George


    The choice of substrates with high phosphorus adsorption capacity is vital for sustainable phosphorus removal from waste water in constructed wetlands. In this study, four substrates were used: quartz sand, anthracite, shale and biological ceramsite. These substrate samples were characterized by Xray diffractometry and scanning electron microscopy studies for their mineral components (chemical components) and surface characteristics. The dynamic experimental results revealed the following ranking order for total phosphorus (TP) removal efficiency: anthracite > biological ceramsite > shale > quartz sand. The adsorptive removal capacities for TP using anthracite, biological ceramsite, shale and quartz sand were 85.87, 81.44, 59.65, and 55.98 mg/kg, respectively. Phosphorus desorption was also studied to analyze the substrates' adsorption efficiency in wastewater treatment as well as the substrates' ability to be reused for treatment. It was noted that the removal performance for the different forms of phosphorus was dependent on the nature of the substrate and the adsorption mechanism. A comparative analysis showed that the removal of particulate phosphorus was much easier using shale. Whereas anthracite had the highest soluble reactive phosphorus (SRP) adsorptive capacity, biological ceramsite had the highest dissolved organic phosphorus (DOP) removal capacity. Phosphorus removal by shale and biological ceramsite was mainly through chemical adsorption, precipitation or biological adsorption. On the other hand, phosphorus removal through physical adsorption (electrostatic attraction or ion exchange) was dominant in anthracite and quartz sand.

  5. Simultaneous removal of carbon and nutrients from an industrial estate wastewater in a single up-flow aerobic/anoxic sludge bed (UAASB) bioreactor. (United States)

    Asadi, A; Zinatizadeh, A A L; Sumathi, S


    Simultaneous removal of carbon and nutrients (CNP) in a single bioreactor is highly significant for energy consumption and control of reactor volume. Basically, nutrients removal is dependant to the ratio of biochemical oxygen demand to chemical oxygen demand (BOD₅/COD). Thus, in this study the treatment of an industrial estate wastewater with low BOD₅/COD ratio in an up-flow aerobic/anoxic sludge bed (UAASB) bioreactor, with an intermittent regime in aeration and discharge, was investigated. Hydraulic retention time (HRT) of 12-36 h and aeration time of 40-60 min/h were selected as the operating variables to analyze, optimize and model the process. In order to analyze the process, 13 dependent parameters as the process responses were studied. From the results, it was found, increasing HRT decreases the CNP removal efficiencies. However, by increasing the BOD₅ fraction of the feed, the total COD (TCOD), slowly biodegradable COD (sbCOD), readily biodegradable COD (rbCOD), total nitrogen (TN), and total phosphorus (TP) removal efficiencies were remarkably increased. Population of heterotrophic, nitrifying and denitrifying bacteria showed good agreement with the results obtained for TCOD and TN removal. The optimum conditions were determined as 12-15 h and 40-60 min/h for HRT and aeration time respectively.

  6. Modeling the Performance of Biological Rapid Sand Filters Used to Remove Ammonium, Iron, and Manganese From Drinking Water

    DEFF Research Database (Denmark)

    Lee, Carson; Albrechtsen, Hans-Jørgen; Smets, Barth F.;

    filter management to performance . Biological rapid sand filters are used for the dual purpose of particle removal (including microorganisms) and contaminant removal through biological activity on the filter media. For drinking water treatment in the United States, biological filters use granular......Although biological rapid sand filters are a well established technology for treating drinking water, there is still a lack of scientific understanding of the processes controlling their performance. For example, the distribution and role of microorganisms in contaminant removal in the filter has...... for chlorine addition following treatment. Under the normal conditions found in many water treatment plants, reduced iron can be oxidized through aeration and the precipitates can be captured by the filter media. Ammonium and manganese can be removed biologically. This research uses both pilot and full scale...

  7. Evaluation of In-situ Sludge Reduction and Enhanced Nutrient Removal in an Integrated Repeatedly Coupling Aerobic and Anaerobic and Oxic-setting-anaerobic System

    Institute of Scientific and Technical Information of China (English)

    Shanshan Yang; Wanqian Guo; Qinglian Wu; Haichao Luo; Simai Peng; Heshan Zheng; Xiaochi Feng; Nanqi Ren∗


    Aiming to achieve simultaneous good performances of in⁃situ sludge reduction and effluent quality, an integrated repeatedly coupling aerobic and anaerobic and oxic⁃setting⁃anaerobic system ( rCAA+OSA ) is developed to reduce sludge production and enhance nutrient removal. Considering the mechanism of in⁃situ sludge reduction in this rCAA+OSA system, the combined effect of energy uncoupling metabolism and sludge cryptic growth maybe attributed to the higher reduction of biomass. Results show that the maximal sludge reduction in this rCAA+OSA system is obtained when the hydraulic retention time ( HRT ) is controlled at 6�5 h, which an increase in 16�67% reduction in excess sludge is achieved compared with OSA system ( HRT of 6�5 h) . When compared the performances of effluent qualities, the enhanced nutrient removal efficiencies also can be observed in this rCAA+OSA system. Three⁃dimensional excitation emission matrix ( 3D⁃EEM ) fluorescence spectroscopy is applied to characterize the effluent organic matters ( EfOM) under different HRTs in the OSA and the rCAA+OSA systems. Analyses of 3D⁃EEM spectra show that more refractory humic⁃like and fulvic⁃like components are observed in the effluent of the OSA system. On the basis of these results, simultaneous enhanced in⁃situ sludge reduction and improved nutrient removal can be obtained in the rCAA+OSA systems.

  8. Vascular plant removal effects on biological N fixation vary across a boreal forest island gradient. (United States)

    Gundale, Michael J; Wardle, David A; Nilsson, Marie-Charlotte


    There is currently much interest in understanding how biodiversity loss affects the functioning of ecosystems, but few studies have evaluated how ecosystem processes change in response to one another following biodiversity loss. We focused on a well-described gradient of 30 forested lake islands in northern Sweden, where island size determines the occurrence of lightning-ignited wildfire, which in turn determines successional stage, plant species composition, and productivity. We investigated the effect of biodiversity loss on biological nitrogen fixation by feathermosses through an experiment consisting of factorial removals of three understory shrub species (Vaccinium myrtillis, Vaccinium vitis-idaea, and Empetrum hermaphroditum) and two plant functional groups (shrubs and tree roots). We tested the hypothesis that, following vascular plant species loss, N fixation rates would be impaired by changes in pools or processes that increase extractable soil N, because changes in the supply rate of N to feathermosses should influence their demand for newly fixed N. Further, we hypothesized that the effects of removals on N fixation would depend on environmental context (i.e., island size), because it has been previously demonstrated that the effect of vascular plant species removal on N recycling pools and processes was strongest on productive islands. The data demonstrated that removal of two shrub species (V. vitis-idaea and E. hermaphroditum) negatively aflected the N fixation of Hylocomium splendens, but positively affected Pleurozium schreberi, resulting in unchanged areal N fixation rates. In the functional removal experiment, tree root removal resulted in a significant negative effect on N fixation. The effects of shrub and root removals on N fixation occurred only on small islands and thus were context dependent. This pattern did not correspond to the effect of shrub and root removal treatments on N-recycling pools or processes, which only occurred in response

  9. Removal of anaerobic soluble microbial products in a biological activated carbon reactor

    Institute of Scientific and Technical Information of China (English)

    Xiaojing Dong; Weili Zhou; Shengbing He


    The soluble microbial products (SMP) in the biological treatment effluent are generally of great amount and are poorly biodegradable.Focusing on the biodegradation of anaerobic SMP,the biological activated carbon (BAC) was introduced into the anaerobic system.The experiments were conducted in two identical lab-scale up-flow anaerobic sludge blanket (UASB) reactors.The high strength organics were degraded in the first UASB reactor (UASB1) and the second UASB (UASB2,i.e.,BAC) functioned as a polishing step to remove SMP produced in UASB1.The results showed that 90% of the SMP could be removed before granular activated carbon was saturated.After the saturation,the SMP removal decreased to 60% on the average.Analysis of granular activated carbon adsorption revealed that the main role of SMP removal in BAC reactor was biodegradation.A strain of SMP-degrading bacteria,which was found highly similar to Klebsiella sp.,was isolated,enriched and inoculated back to the BAC reactor.When the influent chemical oxygen demand (COD) was 10,000 mg/L and the organic loading rate achieved 10 kg COD/(m3·day),the effluent from the BAC reactor could meet the discharge standard without further treatment.Anaerobic BAC reactor inoculated with the isolated Klebsiella was proved to be an effective,cheap and easy technical treatment approach for the removal of SMP in the treatment of easily-degradable wastewater with COD lower than 10,000 mg/L.

  10. Environmental assessment of nutrient recycling from biological pig slurry treatment--impact of fertilizer substitution and field emissions. (United States)

    Brockmann, Doris; Hanhoun, Mary; Négri, Ophélie; Hélias, Arnaud


    Pig slurry treatment is an important means in reducing nitrogen loads applied to farmland. Solid phase separation prior to biological treatment further allows for recovering phosphorus with the solid phase. The organic residues from the pig slurry treatment can be applied as organic fertilizers to farmland replacing mineral fertilizers. The environmental impacts of nutrient recycling from aerobic, biological pig slurry treatment were evaluated applying the life cycle assessment (LCA) methodology. LCA results revealed that direct field emissions from organic fertilizer application and the amount of avoided mineral fertilizers dominated the environmental impacts. A modified plant available nitrogen calculation (PAN) was introduced taking into account calculated nitrogen emissions from organic fertilizer application. Additionally, an equation for calculating the quantity of avoided mineral fertilizers based on the modified PAN calculation was proposed, which accounted for nitrogen emissions from mineral fertilizer application.

  11. Biological and Physiochemical Techniques for the Removal of Zinc from Drinking Water: A Review

    Directory of Open Access Journals (Sweden)

    Naseem Zahra


    Full Text Available Presence of Zinc (II in drinking water beyond permissible limits is considered unsafe for human health. Many different anthropogenic activities including mining, burning of petroleum, industrialization, and urbanization cause a release of considerably higher amounts of zinc into the waterbodies. A permissible limit of 5 mg/L is set by various environmental and pollution control authorities beyond which water may cause respiratory, liver, gonads, and brain disorders. Due to these health hazards, it is important to remove exceeding amounts of zinc from drinking water. Zinc enters drinking water from various sources such as corrosive pipelines, release of industrial effluents, and metal leaching. Different biological and physiochemical techniques are used to remove zinc involving chemical precipitation, ion exchange, adsorption, biosorbents, distillation, ozonation, and membrane filtration technology. Among these technologies, physical process of adsorption using low cost adsorbents is not only economical but abundant, efficient, and easily available. In present review different physiochemical and biological techniques are discussed for the removal of Zinc from drinking water.

  12. Monitoring of Biological Nitrogen Removal in Tannery Wastewater Using a Sequencing Batch Reactor

    Directory of Open Access Journals (Sweden)

    Carrasquero-Ferrer Sedolfo José


    Full Text Available The objective of this research was to relate the biological nitrogen removal in tannery wastewater with profiles of pH, alkalinity and redox potential (ORP using a sequencing batch reactor (SBR with a working volume of 2 L. The reactor worked under two operational sequences: anoxic-aerobic-anoxic (Ax/Ae/Ax and aerobic-anoxic (Ae/Ax, which were combined with two cell retention times (CRT (15 and 25 days, with an operation cycle time (OCT of 11 hours. The profiles were performed by measuring each 15 minutes the following parameters: pH, dissolved oxygen (DO, ORP, and each hour the parameters: total alkalinity, total chemical oxygen demand (DQOT, soluble chemical oxygen demand (DQOS, total Kjeldahl nitrogen (TKN, nitrite (NO2-, nitrate (NO3- and ammonia nitrogen (N-NH4+. Alkalinity and ORP profile were excellent indicators of the processes of biological nitrogen removal. However, pH could not be used as a control parameter, due to the buffering capacity of tannery wastewater. Finally, this research work showed that alkalinity and ORP values can be used as on-line control parameters to monitor the evolution of the nitrogen removal in tannery wastewater (nitrification and denitrification processes.

  13. Removal of stigmasterol from Kraft mill effluent by aerobic biological treatment with steroidal metabolite detection. (United States)

    Chamorro, Soledad; Vergara, Juan P; Jarpa, Mayra; Hernandez, Victor; Becerra, Jose; Vidal, Gladys


    Stigmasterol is a phytosterol contained in Kraft mill effluent that is able to increase over 100% after aerobic biological treatment. This compound can act as an endocrine disrupter as its structure is similar to that of cholesterol. The aim of this study was to evaluate the removal of stigmasterol from Kraft mill effluents treated by a moving bed biofilm reactor (MBBR) with steroidal metabolite detection. The MBBR was operated for 145 days, with a hydraulic retention time of 2 days. Stigmasterol and steroidal metabolites were detected by gas chromatography with a flame ionization detector during MBBR operation. The results show that the MBBR removed 87.4% of biological oxygen demand (BOD5), 61.5% of chemical oxygen demand (COD), 24.5% of phenol and 31.5% of lignin, expressed in average values. The MBBR system successfully removed 100% of the stigmasterol contained in the influent (33 µg L(-1)) after 5 weeks of operation. In that case, the organic load rate was 0.343 kg COD m(-3) d(-1). Furthermore, different steroidal compounds (e.g., testosterone propionate, stigmast-4-en-3-one, 5α-pregnan-12-one-20α-hydroxy, 5α-pregnane-3,11,20-trione and 3α-hydroxy-5α-androstane-11,17-dione were detected in the Kraft mill effluent as potential products of phytosterol biotransformation.

  14. Nearshore biological communities prior to the removal of the Elwha River dams: Chapter 6 in Coastal habitats of the Elwha River, Washington--biological and physical patterns and processes prior to dam removal (United States)

    Rubin, Stephen P.; Miller, Ian M.; Elder, Nancy; Reisenbichler, Reginald R.; Duda, Jeffrey J.; Duda, Jeffrey J.; Warrick, Jonathan A.; Magirl, Christopher S.


    Increases in sediment delivery to coastal waters are expected following removal of dams on the Elwha River, Washington, potentially increasing sediment deposition on the seafloor and suspended sediment in the water column. Biological communities inhabiting shallow, subtidal depths

  15. Functionalized nanoporous silica for the removal of heavy metals from biological systems: adsorption and application. (United States)

    Yantasee, Wassana; Rutledge, Ryan D; Chouyyok, Wilaiwan; Sukwarotwat, Vichaya; Orr, Galya; Warner, Cynthia L; Warner, Marvin G; Fryxell, Glen E; Wiacek, Robert J; Timchalk, Charles; Addleman, R Shane


    Surface-functionalized nanoporous silica, often referred to as self-assembled monolayers on mesoporous supports (SAMMS), has previously demonstrated the ability to serve as very effective heavy metal sorbents in a range of aquatic and environmental systems, suggesting that they may be advantageously utilized for biomedical applications such as chelation therapy. Herein we evaluate surface chemistries for heavy metal capture from biological fluids, various facets of the materials' biocompatibility, and the suitability of these materials as potential therapeutics. Of the materials tested, thiol-functionalized SAMMS proved most capable of removing selected heavy metals from biological solutions (i.e., blood, urine, etc.) Consequentially, thiol-functionalized SAMMS was further analyzed to assess the material's performance under a number of different biologically relevant conditions (i.e., variable pH and ionic strength) to gauge any potentially negative effects resulting from interaction with the sorbent, such as cellular toxicity or the removal of essential minerals. Additionally, cellular uptake studies demonstrated no cell membrane permeation by the silica-based materials generally highlighting their ability to remain cellularly inert and thus nontoxic. The results show that organic ligand functionalized nanoporous silica could be a valuable material for a range of detoxification therapies and potentially other biomedical applications.

  16. A combined biological removal of Cd(2+) from aqueous solutions using Phanerochaete chrysosporium and rice straw. (United States)

    Zhao, Meihua; Zhang, Chaosheng; Zeng, Guangming; Cheng, Min; Liu, Yang


    The removal of Cd(2+) from aqueous solutions by agricultural residues rice straw combined with white rot fungus Phanerochaete chrysosporium (P. chrysosporium) was investigated. The results showed that over 99% of the total Cd(2+) (initial concentration of 150mgL(-1)) was removed at the optimal operating conditions (pH 5.0 at 35°C). We also found that P. chrysosporium could survive under Cd(2+) stress even with an initial Cd(2+) concentration of 250mgL(-1). But when Cd(2+) concentration increased to 250mgL(-1), fungus growth and reproduction were remarkably restrained, and as a result, Cd(2+) removal dropped to 59.2%. It was observed that the fungus biomass and activities of ligninolytic enzymes decreased at some degree under high concentration of Cd(2+) (above 100mgL(-1)). Also, we found that a moderate Cd(2+) stress (below 150mgL(-1)) could stimulate P. chrysosporium's production of the heavy metals chelator - oxalate. This study will provide useful information for the application of biological removal of heavy metal irons from wastewater.

  17. Biological phosphorus removal in sequencing batch reactor with single-stage oxic process. (United States)

    Wang, Dong-Bo; Li, Xiao-Ming; Yang, Qi; Zeng, Guang-Ming; Liao, De-Xiang; Zhang, Jie


    The performance of biological phosphorus removal (BPR) in a sequencing batch reactor (SBR) with single-stage oxic process was investigated using simulated municipal wastewater. The experimental results showed that BPR could be achieved in a SBR without anaerobic phase, which was conventionally considered as a key phase for BPR. Phosphorus (P) concentration 0.22-1.79 mg L(-1) in effluent can be obtained after 4h aeration when P concentration in influent was about 15-20 mg L(-1), the dissolved oxygen (DO) was controlled at 3+/-0.2 mg L(-1) during aerobic phase and pH was maintained 7+/-0.1, which indicated the efficiencies of P removal were achieved 90% above. Experimental results also showed that P was mainly stored in the form of intracellular storage of polyphosphate (poly-P), and about 207.235 mg phosphates have been removed by the discharge of rich-phosphorus sludge for each SBR cycle. However, the energy storage poly-beta-hydroxyalkanoates (PHA) was almost kept constant at a low level (5-6 mg L(-1)) during the process. Those results showed that phosphate could be transformed to poly-P with single-stage oxic process without PHA accumulation, and BPR could be realized in net phosphate removal.

  18. Biologically active carbon filtration for haloacetic acid removal from swimming pool water. (United States)

    Tang, Hao L; Xie, Yuefeng F


    A biologically activate carbon (BAC) filter was continuously operated on site for the treatment of haloacetic acids (HAAs) in an outdoor swimming pool at an average empty bed contact time (EBCT) of 5.8 min. Results showed that BAC filtration was a viable technology for direct removal of HAAs from the pool water with a nominal efficiency of 57.7% by the filter while the chlorine residuals were 1.71 ± 0.90 mg/L during the study. THMs and TOC were not removed and thus were not considered as indicators of the effectiveness of BAC filtration. Increased EBCT in the range of 4.5 and 6.4 min led to improved HAA removal performance, which could be best fit by a logarithmic regression model. BAC filtration also affected the HAA speciation by removing more dichloroacetic acid (DCAA) than trichloroacetic acid (TCAA), resulting in a lower ratio of DCAA/TCAA in the filtered effluent. However, the observation of an overall constant ratio could be attributable to a complex formation and degradation mechanism occurring in swimming pools.

  19. Enrichment and immobilization of sulfide removal microbiota applied for environmental biological remediation of aquaculture area. (United States)

    Zhao, Yang-Guo; Zheng, Yu; Tian, Weijun; Bai, Jie; Feng, Gong; Guo, Liang; Gao, Mengchun


    To remove sulfide in the deteriorating aquaculture sediment and water, sulfide-oxidizing microbiota was enriched from Jiaozhou Bay, China, by using sulfide-rich medium. Composition and structure of microbial communities in the enrichments were investigated by 16S rDNA molecular biotechniques. Results showed that microbial community structure continuously shifted and the abundance of sulfate reducing bacteria, i.e., Desulfobacterium, Desulfococcus and Desulfobacca apparently declined. Several halophile genera, Vibrio, Marinobacter, Pseudomonas, Prochlorococcus, Pediococcus and Thiobacillus predominated finally in the microbiota. The enriched microbiota was capable of removing a maximum of 1000 mg/L sulfide within 12 h with 10% inoculum at pH 7.0, 20-30 °C. After immobilized, the microbiota presented excellent resistance to impact and could completely remove 600 mg/L sulfide in 12 h. Moreover, the immobilized microbiota recovered well even recycled for five times. In conclusion, the immobilized sulfide-removing microbiota showed a quite promising application for biological restoring of sulfide-rich aquaculture environment.

  20. Effect of preozonation on biological stability and organic matter removal from water

    Directory of Open Access Journals (Sweden)

    ZHANG Hongzhuan


    Full Text Available Both preozonation and prechlorination processes were adopted before the conventional drinking water treatment process,and the raw water for each was taken from upstream of Huangpu River.The comparative pilot experiments were conducted at a scale of 1.0 m3·h-1 for each.CODMn,UV254,TOC,and AOC of the finished water were determined after the preozonation process,compared with those after the prechlorination process.The Effect of the preozonation process on organic material removal from water was studied.The biological stability of the finished water after the preozonation process was analyzed.The results show that when CODMn in raw water was 5.56~6.50 m3·L-1,CODMn removal efficiency and UV254 removal rate by pre-ozonation process increased by 2.5% and 6%,respectively,compared with those by pre-chlorination process.TOC removal efficiencies by both processes were not high.AOC in the finished water after the preozonation process was higher obviously than that after the prechlorination process.

  1. Biological treatment process for removing petroleum hydrocarbons from oil field produced waters

    Energy Technology Data Exchange (ETDEWEB)

    Tellez, G.; Khandan, N.


    The feasibility of removing petroleum hydrocarbons from oil fields produced waters using biological treatment was evaluated under laboratory and field conditions. Based on previous laboratory studies, a field-scale prototype system was designed and operated over a period of four months. Two different sources of produced waters were tested in this field study under various continuous flow rates ranging from 375 1/D to 1,800 1/D. One source of produced water was an open storage pit; the other, a closed storage tank. The TDS concentrations of these sources exceeded 50,000 mg/l; total n-alkanes exceeded 100 mg/l; total petroleum hydrocarbons exceeded 125 mg/l; and total BTEX exceeded 3 mg/l. Removals of total n-alkanes, total petroleum hydrocarbons, and BTEX remained consistently high over 99%. During these tests, the energy costs averaged $0.20/bbl at 12 bbl/D.

  2. Removal of hydrogen sulfide from gas streams using biological processes : a review

    Energy Technology Data Exchange (ETDEWEB)

    Syed, M.; Soreanu, G.; Falletta, P.; Beland, M. [Environment Canada, Burlington, ON (Canada). Wastewater Technology Centre


    Hydrogen sulfide (H{sub 2}S) is produced by the anaerobic digestion of biosolids and other organic materials, and can be corrosive to internal combustion engines. This study investigated biological H{sub 2}S removal processes with the aim of overcoming the chemical and disposal costs associated with existing chemically-based removal processes. Current biological H{sub 2}S removal processes were reviewed, and research needs for potential process improvements were identified. Processes included photoautotrophs; chemotrophs; bioreactors for H{sub 2}S removal involving phototrophic bacteria; continuous-flow reactors; phototube reactors; gas-fed batch reactors; bioscrubbers; biofilters; and biotrickling filters. Results of the review suggested that the preferred treatment method for H{sub 2}S gas containing streams depended on the source of the gas. In the case of H{sub 2}S in biogas, anaerobic methods involving phototrophic bacteria provided the inherent advantage of maintaining the anaerobic nature of the gas. Cholorobium limicola was recommended as a desirable bacterium due to its growth using inorganic substrates, its efficiency at converting sulfide to elemental sulfur, and its extracellular production of elemental sulfur. Fixed-film reactors had the greatest potential for cost-effective sulfide conversion. It was noted that light supply is one of the key cost components in the process and poses a major constraint. It was concluded that future research should focus on the development and use of energy efficient LEDs and the proper use of sunlight and reflectors to minimize the electrical energy use. 73 refs., 5 tabs., 5 figs.

  3. Biological sulfate removal from construction and demolition debris leachate: Effect of bioreactor configuration

    Energy Technology Data Exchange (ETDEWEB)

    Kijjanapanich, Pimluck, E-mail: [Pollution Prevention and Resource Recovery Chair Group, UNESCO-IHE Institute for Water Education, Westvest 7, 2611 AX Delft (Netherlands); Do, Anh Tien [Civil and Environmental Engineering, University of South Florida, Tampa, FL 33620 (United States); Annachhatre, Ajit P. [Environmental Engineering and Management, Asian Institute of Technology, PO Box 4, Klongluang, Pathumthani 12120 (Thailand); Esposito, Giovanni [Department of Civil and Mechanical Engineering, University of Cassino and Southern Lazio, Via Di Biasio 43, 03043 Cassino (Italy); Yeh, Daniel H. [Civil and Environmental Engineering, University of South Florida, Tampa, FL 33620 (United States); Lens, Piet N.L. [Pollution Prevention and Resource Recovery Chair Group, UNESCO-IHE Institute for Water Education, Westvest 7, 2611 AX Delft (Netherlands)


    Highlights: • Novel biological technique for gypsum removal from CDD. • CDDS leachate treatment performed using different sulfate reducing bioreactors. • Gypsum in CDD can be used as a source of sulfate for sulfate reducing bacteria. • High calcium concentration (1000 mg L{sup −1}) did not affect the bioreactor performance. - Abstract: Due to the contamination of construction and demolition debris (CDD) by gypsum drywall, especially, its sand fraction (CDD sand, CDDS), the sulfate content in CDDS exceeds the posed limit of the maximum amount of sulfate present in building sand (1.73 g sulfate per kg of sand for the Netherlands). Therefore, the CDDS cannot be reused for construction. The CDDS has to be washed in order to remove most of the impurities and to obtain the right sulfate content, thus generating a leachate, containing high sulfate and calcium concentrations. This study aimed at developing a biological sulfate reduction system for CDDS leachate treatment and compared three different reactor configurations for the sulfate reduction step: the upflow anaerobic sludge blanket (UASB) reactor, inverse fluidized bed (IFB) reactor and gas lift anaerobic membrane bioreactor (GL-AnMBR). This investigation demonstrated that all three systems can be applied for the treatment of CDDS leachate. The highest sulfate removal efficiency of 75–85% was achieved at a hydraulic retention time (HRT) of 15.5 h. A high calcium concentration up to 1000 mg L{sup −1} did not give any adverse effect on the sulfate removal efficiency of the IFB and GL-AnMBR systems.

  4. 底栖藻类-苦草对猪粪废水中营养物质的去除效果%Nutrient Removal Rates from Swine Wastewater Using Periphyton-Vallisneria Natan

    Institute of Scientific and Technical Information of China (English)

    顾新跃; 何月; 张秀青; 王青; 裴国凤


    Water plants are often used to remove nutrients from wastewater. This research was conducted to assess the efficiency of nutrient removal from swine wastewater using biological treatment system in a laboratory-scale experiment with periphyton and submerged macro-phyte-V allisneria natan during 32 days. The systems included high, medium and low concentrations of nutrients in wastewater. The maxi-mum removal rates of chemical oxygen demand(COD)were more than 86%at high concentrations. The average phosphorus(P)and nitro-gen(N)removal rates were respectively over 62%and 70%for both high and medium concentrations in mixed nutrient systems, greater than in single nutrient systems(59%and 65%). Changes of physiological activities showed that V . natan suffered a short-term stress at high nu-trient concentrations. However, such stresses could be alleviated by the presence of periphyton. In conclusion, the optimum condition for V . natan would be medium concentrations of nutrients with periphyton.%为了探究底栖藻类和沉水植物(苦草)对猪粪废水的处理效果,及苦草恢复重建的环境条件,通过设置不同浓度的猪粪废水处理,进行了为期32 d的室内模拟实验。结果表明:底栖藻类、苦草、底栖藻类-苦草处理组对高浓度猪粪废水的COD和氮、磷均存在显著的去除效果;COD的最大去除率均大于86%,底栖藻类-苦草混合培养对高、中浓度猪粪废水中磷、氮的平均去除率分别大于62%和70%,高于二者单独培养的处理组(均小于59%和65%)。实验期间,底栖藻类、苦草和浮游藻类Chla含量的变化以及苦草的CAT、MDA含量变化表明,高浓度的猪粪废水会对苦草产生短期的逆境胁迫,但底栖藻类的存在可以减缓高浓度氮磷对苦草的胁迫效应,在中浓度氮磷且有底栖藻类存在的条件下,有利于苦草的恢复重建。

  5. Performance of biological phosphorus removal and characteristics of microbial community in the oxic-settling-anaerobic process by FISH analysis

    Institute of Scientific and Technical Information of China (English)

    Jian-fang WANG; Qing-liang ZHAO; Wen-biao JIN; Shi-jie YOU; Jin-na ZHANG


    Performance of biological phosphorus removal in the oxic-settling-anaerobic (OSA) process was investigated. Cell staining and fluorescent in situ hybridization (FISH) were used to analyze characteristics and microbial community of sludge.Experimental results showed that phosphorus removal efficiency was near 60% and the amount of biological phosphorus accumulation in aerobic sludge of the OSA system was up to 26.9 mg/g. Biological phosphorus removal efficiency was partially inhibited by carbon sources in the continuous OSA system. Contrasted to the OSA system, biological phosphorus removal efficiency was enhanced by 14% and the average total phosphorus (TP) contents of aerobic sludge were increased by 0.36 mg/g when sufficient carbon sources were supplied in batch experiments. Staining methods indicated that about 35% of microorganisms had typical characteristics of phosphorus accumulating organisms (PAOs). FISH analysis demonstrated that PAOMIX-binding bacteria were predominant microbial communities in the OSA system, which accounted for around 28% of total bacteria.

  6. A metabolic model for members of the genus Tetrasphaera involved in enhanced biological phosphorus removal

    DEFF Research Database (Denmark)

    Kristiansen, Rikke; Nguyen, Hien Thi Thu; Saunders, Aaron Marc


    Members of the genus Tetrasphaera are considered to be putative polyphosphate accumulating organisms (PAOs) in enhanced biological phosphorus removal (EBPR) from wastewater. Although abundant in Danish full-scale wastewater EBPR plants, how similar their ecophysiology is to ‘Candidatus...... incorporate central aspects of carbon and phosphorus metabolism critical to understanding their behavior under the alternating anaerobic/aerobic conditions encountered in EBPR systems. Key features of these metabolic pathways were investigated in pure cultures, although poor growth limited their analyses to T...

  7. Application of vascular aquatic plants for pollution removal, energy and food production in a biological system (United States)

    Wolverton, B. C.; Barlow, R. M.; Mcdonald, R. C.


    Vascular aquatic plants such as water hyacinths (Eichhornia crassipes) (Mart.) Solms and alligator weeds (Alternanthera philoxeroides) (Mart.) Griesb., when utilized in a controlled biological system (including a regular program of harvesting to achieve maximum growth and pollution removal efficiency), may represent a remarkably efficient and inexpensive filtration and disposal system for toxic materials and sewage released into waters near urban and industrial areas. The harvested and processed plant materials are sources of energy, fertilizer, animal feed, and human food. Such a system has industrial, municipal, and agricultural applications.

  8. Removal of biological stains from aqueous solution using a flow-through decontamination procedure. (United States)

    Lunn, G; Klausmeyer, P J; Sansone, E B


    Chromatography columns filled with Amberlite XAD-16 were used to decontaminate, using a continuous flow-through procedure, aqueous solutions of the following biological stains: acridine orange, alcian blue 8GX, alizarin red S, azure A, azure B, brilliant blue G, brilliant blue R, Congo red, cresyl violet acetate, crystal violet, eosin B, eosin Y, erythrosin B, ethidium bromide, Giemsa stain, Janus green B, methylene blue, neutral red, nigrosin, orcein, propidium iodide, rose Bengal, safranine O, toluidine blue O, and trypan blue. Adsorption was most efficient for stains of lower molecular weight (removing stains from aqueous solution.

  9. Intensification of ammonia removal from waste water in biologically active zeolitic ion exchange columns. (United States)

    Almutairi, Azel; Weatherley, Laurence R


    The use of nitrification filters for the removal of ammonium ion from waste-water is an established technology deployed extensively in municipal water treatment, in industrial water treatment and in applications such as fish farming. The process involves the development of immobilized bacterial films on a solid packing support, which is designed to provide a suitable host for the film, and allow supply of oxygen to promote aerobic action. Removal of ammonia and nitrite is increasingly necessary to meet drinking water and discharge standards being applied in the US, Europe and other places. Ion-exchange techniques are also effective for removal of ammonia (as the ammonium ion) from waste water and have the advantage of fast start-up times compared to biological filtration which in some cases may take several weeks to be fully operational. Here we explore the performance of ion exchange columns in which nitrifying bacteria are cultivated, with the goal of a "combined" process involving simultaneous ion-exchange and nitrification, intensified by in-situ aeration with a novel membrane module. There were three experimental goals. Firstly, ion exchange zeolites were characterized and prepared for comparative column breakthrough studies for ammonia removal. Secondly effective in-situ aeration for promotion of nitrifying bacterial growth was studied using a number of different membranes including polyethersulfone (PES), polypropylene (PP), nylon, and polytetra-fluoroethylene (PTFE). Thirdly the breakthrough performance of ion exchange columns filled with zeolite in the presence of aeration and in the presence of nitrifying bacteria was determined to establish the influence of biomass, and aeration upon breakthrough during ammonium ion uptake. The methodology adopted included screening of two types of the naturally occuring zeolite clinoptilolite for effective ammonia removal in continuous ion-exchange columns. Next, the performance of fixed beds of clinoptilolite in the

  10. Coastal habitats of the Elwha River, Washington- Biological and physical patterns and processes prior to dam removal (United States)

    Duda, Jeffrey J.; Warrick, Jonathan A.; Magirl, Christopher S.


    This report includes chapters that summarize the results of multidisciplinary studies to quantify and characterize the current (2011) status and baseline conditions of the lower Elwha River, its estuary, and the adjacent nearshore ecosystems prior to the historic removal of two long-standing dams that have strongly influenced river, estuary, and nearshore conditions. The studies were conducted as part of the U.S. Geological Survey Multi-disciplinary Coastal Habitats in Puget Sound (MD-CHIPS) project. Chapter 1 is the introductory chapter that provides background and a historical context for the Elwha River dam removal and ecosystem restoration project. In chapter 2, the volume and timing of sediment delivery to the estuary and nearshore are discussed, providing an overview of the sediment stored in the two reservoirs and the expected erosion mechanics of the reservoir sediment deposits after removal of the dams. Chapter 3 describes the geological background of the Olympic Peninsula and the geomorphology of the Elwha River and nearshore. Chapter 4 details a series of hydrological data collected by the MD-CHIPS Elwha project. These include groundwater monitoring, surface water-groundwater interactions in the estuary, an estimated surface-water budget to the estuary, and a series of temperature and salinity measurements. Chapter 5 details the work that has been completed in the nearshore, including the measurement of waves, tides, and currents; the development of a numerical hydrodynamic model; and a description of the freshwater plume entering the Strait of Juan de Fuca. Chapter 6 includes a characterization of the nearshore benthic substrate developed using sonar, which formed a habitat template used to design scuba surveys of the benthic biological communities. Chapter 7 describes the ecological studies conducted in the lower river and estuary and includes characterization of juvenile salmon diets and seasonal estuary utilization patterns using otolith analysis to

  11. The Investigation and Comparison of Furfural Removal from Wastewater using Cyclic Biological Reactor (CBR and Fusarium Culmorum Granules

    Directory of Open Access Journals (Sweden)

    Mostafa Leili


    Conclusion: Under different operating conditions of biological systems, high removal efficiency of furfural was observed, but CBR in comparison with Fusarium culmorum granules reached the optimum and desired removal efficiency in shorter time. Therefore, these systems can be developed and replaced with chemical methods to treat furfural containing wastewater.

  12. Physico-chemical factors affecting the E.coli removal in a rotating biological contactor (RBC) treating UASB effluent

    NARCIS (Netherlands)

    Tafwik, A.; Klapwijk, A.; Buuren, van J.C.L.; El-Gohary, F.; Lettinga, G.


    The removal mechanism of E coli from UASB effluent using a Rotating Biological Contractor (RBC) has been investigated. Preliminary batch experiments in a RBC indicate a first-order removal kinetics. Variation in the dissolved oxygen concentration and E coli counts over the depth of the RBC has been

  13. Biological redox cycling of iron in nontronite and its potential application in nitrate removal. (United States)

    Zhao, Linduo; Dong, Hailiang; Kukkadapu, Ravi K; Zeng, Qiang; Edelmann, Richard E; Pentrák, Martin; Agrawal, Abinash


    Biological redox cycling of structural Fe in phyllosilicates is an important but poorly understood process. The objective of this research was to study microbially mediated redox cycles of Fe in nontronite (NAu-2). During the reduction phase, structural Fe(III) in NAu-2 served as electron acceptor, lactate as electron donor, AQDS as electron shuttle, and dissimilatory Fe(III)-reducing bacterium Shewanella putrefaciens CN32 as mediator in bicarbonate- and PIPES-buffered media. During the oxidation phase, biogenic Fe(II) served as electron donor and nitrate as electron acceptor. Nitrate-dependent Fe(II)-oxidizing bacterium Pseudogulbenkiania sp. strain 2002 was added as mediator in the same media. For all three cycles, structural Fe in NAu-2 was able to reversibly undergo three redox cycles without significant dissolution. Fe(II) in bioreduced samples occurred in two distinct environments, at edges and in the interior of the NAu-2 structure. Nitrate reduction to nitrogen gas was coupled with oxidation of edge-Fe(II) and part of interior-Fe(II) under both buffer conditions, and its extent and rate did not change with Fe redox cycles. These results suggest that biological redox cycling of structural Fe in phyllosilicates is a reversible process and has important implications for biogeochemical cycles of carbon, nitrogen, and other nutrients in natural environments.

  14. Biological sulphide removal from anaerobically treated domestic sewage: reactor performance and microbial community dynamics. (United States)

    Garcia, Graziella Patrício Pereira; Diniz, Renata Côrtes Oliveira; Bicalho, Sarah Kinaip; Franco, Vitor Araujo de Souza; Gontijo, Eider Max de Oliveira; Toscano, Rodrigo Argolo; Canhestro, Kenia Oliveira; Santos, Merly Rita Dos; Carmo, Ana Luiza Rodrigues Dias; Lobato, Livia Cristina S; Brandt, Emanuel Manfred F; Chernicharo, Carlos A L; Calabria de Araujo, Juliana


    We developed a biological sulphide oxidation system and evaluated two reactors (shaped similar to the settler compartment of an up-flow anaerobic sludge blanket [UASB] reactor) with different support materials for biomass retention: polypropylene rings and polyurethane foam. The start-up reaction was achieved using microorganisms naturally occurring on the open surface of UASB reactors treating domestic wastewater. Sulphide removal efficiencies of 65% and 90% were achieved with hydraulic retention times (HRTs) of 24 and 12 h, respectively, in both reactors. However, a higher amount of elemental sulphur was formed and accumulated in the biomass from reactor 1 (20 mg S(0) g(-1) VTS) than in that from reactor 2 (2.9 mg S(0) g(-1) VTS) with an HRT of 24 h. Denaturing gradient gel electrophoresis (DGGE) results revealed that the the pink and green biomass that developed in both reactors comprised a diverse bacterial community and had sequences related to phototrophic green and purple-sulphur bacteria such as Chlorobium sp., Chloronema giganteum, and Chromatiaceae. DGGE band patterns also demonstrated that bacterial community was dynamic over time within the same reactor and that different support materials selected for distinct bacterial communities. Taken together, these results indicated that sulphide concentrations of 1-6 mg L(-1) could be efficiently removed from the effluent of a pilot-scale UASB reactor in two sulphide biological oxidation reactors at HRTs of 12 and 24 h, showing the potential for sulphur recovery from anaerobically treated domestic wastewater.

  15. Integration of photocatalysis and biological treatment for azo dye removal--application to AR183. (United States)

    Chebli, Derradji; Fourcade, Florence; Brosillon, Stephan; Nacef, Saci; Amrane, Abdeltif


    The feasibility of coupling photocatalysis with biological treatment to treat effluents containing azo dyes was examined in this work. With this aim, the degradation of Acid Red 183 was investigated. The very low biodegradability of AR183 was confirmed beforehand by measuring the biological oxygen demand (BOD5). Photocatalysis experiments were carried out in a closed-loop step photoreactor. The reactor walls were covered by TiO2 catalyst coated on non-woven paper, and the effluent flowed over the photocatalyst as a thin falling film. The removal of the dye was 82.7% after 4 h, and a quasi-complete decolorization (98.5%) was obtained for 10 h of irradiation (initial concentration 100 mg L(-1)). The decrease in concentration followed pseudo-first-order kinetics, with a constant k of 0.47 h(-1). Mineralization and oxidation yields were 80% and 75%, respectively, after 10 h of pretreatment. Therefore, even if target compound oxidation occurs (COD removal), indicating a modification to the chemical structure, the concomitant high mineralization was not in favour of subsequent microbial growth. The BOD5 measurement confirmed the non-biodegradability of the irradiated solution, which remained toxic since the EC50 decreased from 35 to 3 mg L(-1). The proposed integrated process appeared, therefore, to be not relevant for the treatment of AR183. However, this result should be confirmed for other azo dyes.

  16. Biological removal of the xenobiotic trichloroethylene (TCE) through cometabolism in nitrifying systems. (United States)

    Kocamemi, B Alpaslan; Ceçen, F


    In the present study, cometabolic TCE degradation was evaluated using NH(4)-N as the growth-substrate. At initial TCE concentrations up to 845 microg/L, TCE degradation followed first-order kinetics. The increase in ammonium utilization rate favored the degradation of TCE. This ensured that biological transformation of TCE in nitrifying systems is accomplished through a cometabolic pathway by the catalysis of non-specific ammonia oxygenase enzyme of nitrifiers. The transformation yield (T(y)) of TCE, the amount of TCE degraded per unit mass of NH(4)-N, strongly depended on the initial NH(4)-N and TCE concentrations. In order to allow a rough estimation of TCE removal and nitrification at different influent TCE and NH(4)-N concentrations, a linear relationship was developed between 1/T(y) and the initial NH(4)-N/TCE ratio. The estimated T(y) values lead to the conclusion that nitrifying systems are promising candidates for biological removal of TCE through cometabolism.

  17. Removal of Furfural From Wastewater Using Integrated Catalytic Ozonation and Biological Approaches

    Directory of Open Access Journals (Sweden)

    Mostafa Leili


    Full Text Available Furfural with a chemical formula of C5H4O2 is a toxic compound which has several health problems for both humans and environment. It has a few exposure routes for entering the human body such as oral, dermal or nasal. In the present study, the efficacies of an integrated catalytic ozonation process (COP and novel cyclic biological reactor (CBR were explored for the removal of furfural from aqueous solutions. Activated carbon was purchased from Merck Company. It had a Brunauer, Emmett, and Teller (BET specific surface area of 1100 m2/g, with an average micropore volume and size of 0.385 cm3/g and 595 µm, respectively. The results indicated that 30% pretreatment with COP could increase furfural and chemical oxygen demand (COD removal efficiency with CBR 5.56% and 27.01%, respectively. With 70% pretreatment by COP, 98.57% furfural and 95.34% COD removal efficiencies happen in CBR. Generally, batch and continuous experiments showed that the integrated COP/CBR could be efficient in eliminating furfural from wastewater and thus may be a promising technique for treating furfural-containing wastewater.

  18. A Biophysicochemical Model for NO Removal by the Chemical Absorption-Biological Reduction Integrated Process. (United States)

    Zhao, Jingkai; Xia, Yinfeng; Li, Meifang; Li, Sujing; Li, Wei; Zhang, Shihan


    The chemical absorption-biological reduction (CABR) integrated process is regarded as a promising technology for NOx removal from flue gas. To advance the scale-up of the CABR process, a mathematic model based on mass transfer with reaction in the gas, liquid, and biofilm was developed to simulate and predict the NOx removal by the CABR system in a biotrickling filter. The developed model was validated by the experimental results and subsequently was used to predict the system performance under different operating conditions, such as NO and O2 concentration and gas and liquid flow rate. NO distribution in the gas phase along the biotrickling filter was also modeled and predicted. On the basis of the modeling results, the liquid flow rate and total iron concentration were optimized to achieve >90% NO removal efficiency. Furthermore, sensitivity analysis of the model revealed that the performance of the CABR process was controlled by the bioreduction activity of Fe(III)EDTA. This work will provide the guideline for the design and operation of the CABR process in the industrial application.

  19. Biological phosphorus removal during high-rate, low-temperature, anaerobic digestion of wastewater

    Directory of Open Access Journals (Sweden)

    Ciara eKeating


    Full Text Available We report, for the first time, extensive biologically-mediated phosphate removal from wastewater during high-rate anaerobic digestion (AD. A hybrid sludge bed/fixed-film (packed pumice stone reactor was employed for low-temperature (12°C anaerobic treatment of synthetic sewage wastewater. Successful phosphate removal from the wastewater (up to 78% of influent phosphate was observed, mediated by biofilms in the reactor. Scanning electron microscopy and energy dispersive X-ray analysis revealed the accumulation of elemental phosphorus (~2% within the sludge bed and fixed-film biofilms. 4’, 6-diamidino-2-phenylindole (DAPI staining indicated phosphorus accumulation was biological in nature and mediated through the formation of intracellular inorganic polyphosphate (polyP granules within these biofilms. DAPI staining further indicated that polyP accumulation was rarely associated with free cells. Efficient and consistent chemical oxygen demand (COD removal was recorded, throughout the 732-day trial, at applied organic loading rates between 0.4-1.5 kg COD m-3 d-1 and hydraulic retention times of 8-24 hours, while phosphate removal efficiency ranged from 28-78% on average per phase. Analysis of protein hydrolysis kinetics and the methanogenic activity profiles of the biomass revealed the development, at 12˚C, of active hydrolytic and methanogenic populations. Temporal microbial changes were monitored using Illumina Miseq analysis of bacterial and archaeal 16S rRNA gene sequences. The dominant bacterial phyla present in the biomass at the conclusion of the trial were the Proteobacteria and Firmicutes and the dominant archaeal genus was Methanosaeta. Trichococcus and Flavobacterium populations, previously associated with low temperature protein degradation, developed in the reactor biomass. The presence of previously characterised polyphosphate accumulating organisms (PAOs such as Rhodocyclus, Chromatiales, Actinobacter and Acinetobacter was

  20. Kinetic analysis of anaerobic phosphorus release during biological phosphorus removal process

    Institute of Scientific and Technical Information of China (English)

    DOU Junfeng; LUO Guyuan; LIU Xiang


    Enhanced biological phosphorus removal(EBPR)is a commonly used and sustainable method for phosphorus removal from wastewater.Poly-β-hydroxybutyrate(PHB),polyphosphate,and glycogen are three kinds of intracellular storage polymers in phosphorus accumulation organisms.The variation of these polymers under different conditions has an apparent influence on anaerobic phosphorus release,which is very important for controlling the performance of EBPR.To obtain the mechanism and kinetic character of anaerobic phosphorus release,a series of batch experiments were performed using the excessively aerated sludge from the aerobic unit of the biological phosphorus removal system in this study.The results showed that the volatile suspended solid(vss)had an increasing trend,while the mixed liquid suspended sludge(MLSS)and ashes were reduced during the anaerobic phosphorus release process.The interruption of anaerobic HAc-uptake and phosphorus-release occurs when the glycogen in the phosphorus-accumulating-organisms is exhausted.Under the condition of lower initial HAc-COD,HAc became the limiting factor after some time for anaerobic HAc uptake.Under the condition of higher initial HAc-COD,HAc uptake was stopped because of the depletion of glycogen in the microorganisms.The mean ratio of △ρP/△ρPHB,△ρGLY/△ρPHB,△ρP/△COD,and △ρPHB/△COD was 0.48,0.50,0.44.and 0.92.respectively,which was nearly the same as the theoretical value.The calibrated kinetic parameters of the HAc-uptake and phosphorus-release model were evaluated as Kgly was 0.005,and KCOD was 3 mg/L.An apparently linear correlation was observed between the ratio of △ρP/△COD and pH of the solution,and the equation between them was obtained in this study.

  1. Impact of salinity on organic matter and nitrogen removal from a municipal wastewater RO concentrate using biologically activated carbon coupled with UV/H2O2. (United States)

    Pradhan, Shovana; Fan, Linhua; Roddick, Felicity A; Shahsavari, Esmaeil; Ball, Andrew S


    The concentrate streams generated from reverse osmosis (RO)-based municipal wastewater reclamation processes contain organic substances and nutrients at elevated concentrations, posing environmental and health risks on their disposal to confined receiving environments such as bays. The impact of salinity (TDS at 7, 10 and 16 g/L) of a RO concentrate (ROC) on the treatment efficiency of a biological activated carbon (BAC) system after pre-oxidation with UV/H2O2 was characterised in terms of removal of organic matter and nitrogen species, and the bacterial communities. Organic matter removal was comparable for the ROC over the tested salinity range, with 45-49% of DOC and 70-74% of UVA254 removed by the combined treatment. However, removal in total nitrogen (TN) was considerably higher for the ROC at the high salinity (TDS ∼ 16 mg/L) compared with the low (∼7 g/L) and medium salinity (∼10 g/L). Effective nitrification with high ammonium removal (>90%) was achieved at all salinity levels, whereas greater denitrification (39%) was obtained at high salinity than low (23%) and medium salinity (27%) which might suggest that the bacterial communities contributing to the greater denitrification were more halotolerant. Microbiological characterisation using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) and culture based techniques showed that diversified bacterial communities were present in the BAC system as evident from different 16S rDNA. The major bacterial groups residing on the BAC media belonged to Bacillus (Firmicutes), Pseudomonas (γ-Proteobacteria), and Rhodococcus (Actinobacteria) for all salinity levels, confirming that these microbial communities could be responsible for carbon and nitrogen removal at the different salinity levels. This has implications in understanding the effectiveness and robustness of the BAC system over the salinity range of the ROC and so would be useful for optimising the treatment efficiency of

  2. Cultivation of Chlorella sp. using raw dairy wastewater for nutrient removal and biodiesel production: Characteristics comparison of indoor bench-scale and outdoor pilot-scale cultures. (United States)

    Lu, Weidong; Wang, Zhongming; Wang, Xuewei; Yuan, Zhenhong


    The biomass productivity and nutrient removal capacity of simultaneous Chlorella sp. cultivation for biodiesel production and nutrient removal in raw dairy wastewater (RDW) in indoor bench-scale and outdoor pilot-scale photobioreactors were compared. Results from the current work show that maximum biomass productivity in indoor bench-scale cultures can reach 260 mg L(-1) day(-1), compared to that of 110 mg L(-1) day(-1) in outdoor pilot-scale cultures. Maximum chemical oxygen demand (COD), total nitrogen (TN), and total phosphorous (TP) removal rate obtained in indoor conditions was 88.38, 38.34, and 2.03 mg L(-1) day(-1), respectively, this compared to 41.31, 6.58, and 2.74 mg L(-1) day(-1), respectively, for outdoor conditions. Finally, dominant fatty acids determined to be C16/C18 in outdoor pilot-scale cultures indicated great potential for scale up of Chlorella sp. cultivation in RDW for high quality biodiesel production coupling with RDW treatment.

  3. Decentralized two-stage sewage treatment by chemical-biological flocculation combined with microalgae biofilm for nutrient immobilization in a roof installed parallel plate reactor. (United States)

    Zamalloa, Carlos; Boon, Nico; Verstraete, Willy


    In this lab-scale study, domestic wastewater is subjected to a chemical biological adsorption (A-stage), followed by treatment in an innovative roof installed parallel plate microalgae biofilm reactor for nutrient immobilization (I-stage). The A-stage process was operated at a hydraulic retention time (HRT) of 1h and a solid retention time of 1day (FeSO(4) as flocculant). The I-stage, which consequently received the effluent of the A-stage process, was operated at an HRT of 1day and exposed to natural light. The overall system removed on average 74% of the total chemical oxygen demand, 82% of the total suspended solids, 67% of the total nitrogen and 96% of the total phosphorous in the wastewater. The design involves a relatively low capital and operating cost which is in the order of 0.5€/m(3) wastewater treated. These aspects suggest that the A/I process can be used as a decentralized domestic wastewater treatment system.

  4. Removal of livestock wastewater nutrient by mangrove systems%红树林系统处理牲畜废水营养盐的研究

    Institute of Scientific and Technical Information of China (English)

    叶勇; 谭凤仪; 卢昌义


    The present investigation compared the capacity of greenhouse pot-cultivation systems under two salinity conditions (freshwater and saline water) with two main mangrove species,Bruguiera gymnorrhiza and Kandelia candel,to remove nutrients from livestock wastewater.The increasing times of P contents in plants receiving livestock wastewater were 1—4 times that of the controls,much more than those of N contents (0.04—1.30 times).The removal efficiencies of N nutrients from livestock wastewater were 84.3% and 95.5% respectively by Kandelia candel and Bruguiera gymnorrhiza pot-cultivation systems under freshwater condition and 92.7% and 98.0% under saline water condition.P nutrient removal efficiencies by Kandelia candel and Bruguiera gymnorrhiza systems under freshwater condition were 79.2% and 91.8% respectively and 88.0% and 97.8% under saline water condition.Salinity condition has no significant effect on the N nutrient removal by Kandelia candel plants.The P removal efficiencies by Kandelia candel and Bruguiera gymnorrhiza plants were less than 4% and much lower than those of N.Under both salinity conditions,higher N/P absorption ratios by plants were found in Bruguiera gymnorrhiza plants (11.64 and 10.64 under freshwater and saline water conditions respectively).Most of the nutrients retained to the systems due to the discharges of livestock wastewater were removed by soils.Most N nutrients retained in soils lost away from the systems.%在2种盐度条件下(淡水与盐度30的人工海水)通过温室盆栽系统对比研究了2种主要红树植物木榄和秋茄对牲畜废水的处理效应.牲畜废水的加入使植物体P含量增加1—4倍,N含量增加0.04—1.30倍.淡水条件下秋茄和木榄系统N的处理效率分别为84.3%和95.5%,海水条件下则为92.7%和98.0%.淡水条件下秋茄和木榄系统P的处理效率分别为79.2%和91.8%,海水条件下则为88.0%和97.8%.盐度对秋茄植物体N的去除无显著效应.2种植

  5. Nutrient cycling and soil biology in row crop systems under intensive tillage (United States)

    Recent interest in management of the soil biological component to improve soil health requires a better understanding on how management practices (e.g., tillage) and environmental conditions influence soil organisms. Intensive tillage often results in reduced organic matter content in the surface so...

  6. Occurrence of cyclophosphamide and ifosfamide in aqueous environment and their removal by biological and abiotic wastewater treatment processes. (United States)

    Česen, Marjeta; Kosjek, Tina; Laimou-Geraniou, Maria; Kompare, Boris; Širok, Brane; Lambropolou, Dimitra; Heath, Ester


    Cytostatic drug residues in the aqueous environment are of concern due to their possible adverse effects on non-target organisms. Here we report the occurrence and removal efficiency of cyclophosphamide (CP) and ifosfamide (IF) by biological and abiotic treatments including advanced oxidation processes (AOPs). Cyclophosphamide was detected in hospital wastewaters (14-22,000 ng L(-1)), wastewater treatment plant influents (19-27 ng L(-1)) and effluent (17 ng L(-1)), whereas IF was detected only in hospital wastewaters (48-6800 ng L(-1)). The highest removal efficiency during biological treatment (attached growth biomass in a flow through bioreactor) was 59 ± 15% and 35 ± 9.3% for CP and IF, respectively. Also reported are the removal efficiencies of both compounds from wastewater using hydrodynamic cavitation (HC), ozonation (O3) and/or UV, either individually or in combination with hydrogen peroxide (H2O2). Hydrodynamic cavitation did not remove CP and IF to any significant degree. The highest removal efficiencies: 99 ± 0.71% for CP and 94 ± 2.4% for IF, were achieved using UV/O3/H2O2 at 5 g L(-1) for 120 min. When combined with biological treatment, removal efficiencies were >99% for both compounds. This is the first report of combined biological and AOP treatment of CP and IF from wastewater with a removal efficiency >99%.

  7. Colour and organic removal of biologically treated coffee curing wastewater by electrochemical oxidation method

    Institute of Scientific and Technical Information of China (English)


    The treatment of biologically treated wastewater of coffee-curing industry by the electrochemical oxidation using steel anode were investigated. Bench-scale experiments were conducted for activated sludge process on raw wastewater and the treated effluents were further treated by electrochemical oxidation method for its color and organic content removal. The efficiency of the process was determined in terms of removal percentage of COD, BOD and color during the course of reaction. Several operating parameters like time, pH and current density were examined to ascertain their effects on the treatment efficiency. Steel anode was found to be effective for the COD and color removal with anode efficiency of 0.118 kgCOD-1A-1m-2 and energy consumption 20.61 of COD at pH 9. The decrease in pH from 9 to 3 found to increase the anode efficiency from 0.118 kgCOD-1A-1m-2 to 0.144 of COD while decrease the energy consumption from 20.61 of COD to12 .86 of COD. The pH of 5 was considered an ideal from the present treatment process as it avoids the addition of chemicals for neutralization of treated effluents and also economical with respect to energy consumption. An empirical relation developed for relationship between applied current density and COD removal efficiency showed strong predictive capability with coefficient of determination of 96.5%.

  8. Changes in soil carbon and nutrients following 6 years of litter removal and addition in a tropical semi-evergreen rain forest (United States)

    Tanner, Edmund Vincent John; Sheldrake, Merlin W. A.; Turner, Benjamin L.


    Increasing atmospheric CO2 and temperature may increase forest productivity, including litterfall, but the consequences for soil organic matter remain poorly understood. To address this, we measured soil carbon and nutrient concentrations at nine depths to 2 m after 6 years of continuous litter removal and litter addition in a semi-evergreen rain forest in Panama. Soils in litter addition plots, compared to litter removal plots, had higher pH and contained greater concentrations of KCl-extractable nitrate (both to 30 cm); Mehlich-III extractable phosphorus and total carbon (both to 20 cm); total nitrogen (to 15 cm); Mehlich-III calcium (to 10 cm); and Mehlich-III magnesium and lower bulk density (both to 5 cm). In contrast, litter manipulation did not affect ammonium, manganese, potassium or zinc, and soils deeper than 30 cm did not differ for any nutrient. Comparison with previous analyses in the experiment indicates that the effect of litter manipulation on nutrient concentrations and the depth to which the effects are significant are increasing with time. To allow for changes in bulk density in calculation of changes in carbon stocks, we standardized total carbon and nitrogen on the basis of a constant mineral mass. For 200 kg m-2 of mineral soil (approximately the upper 20 cm of the profile) about 0.5 kg C m-2 was "missing" from the litter removal plots, with a similar amount accumulated in the litter addition plots. There was an additional 0.4 kg C m-2 extra in the litter standing crop of the litter addition plots compared to the control. This increase in carbon in surface soil and the litter standing crop can be interpreted as a potential partial mitigation of the effects of increasing CO2 concentrations in the atmosphere.

  9. Effect of Slash Burning on Nutrient Removal and Soil Fertility in Chinese Fir and Evergreen Broadleaved Forests of Mid-Subtropical China

    Institute of Scientific and Technical Information of China (English)


    A Chinese fir forest (Cunninghamia lanceolata, CF) and an evergreen broadleaved forest (EB) located inFujian Province, southeastern China, were examined following slash burning to compare nutrient capital andtopsoil properties with pre-burn levels. After fire, nutrient (N, P and K) removal from burning residues wasestimated at 302.5 kg ha-1 in the CF and 644.8 kg ha-1 in the EB. Fire reduced the topsoil capitals of totalN and P by about 20% and 10%, respectively, in both forests, while K capital was increased in the topsoils ofboth forests following fire. Total site nutrient loss through surface erosion was 28.4 kg (N) ha-1, 8.4 kg (P)ha-1 and 328.7 kg (K) ha-1 in the CF. In the EB, the losses of total N, P and K were 58.5, 10.5 and 396.3kg ha-1, respectively. Improvement of soil structure and increase in mineralization of nutrients associatedwith increased microbe number and enzyme activities and elevated soil respiration occurred 5 days after fire.However, organic matter and available nutrient contents and most of other soil parameters declined one yearafter fire on the burned CF and EB topsoils. These results suggest that short-term site productivity canbe stimulated immediately, but reduced subsequently by soil and water losses, especially in South China,where high-intensity precipitation, steep slopes and fragile soil can be expected. Therefore, the silviculturalmeasurements should be developed in plantation management.

  10. Enhanced Removal of Lead by Chemically and Biologically Treated Carbonaceous Materials

    Directory of Open Access Journals (Sweden)

    Mohamed E. Mahmoud


    Full Text Available Hybrid sorbents and biosorbents were synthesized via chemical and biological treatment of active carbon by simple and direct redox reaction followed by surface loading of baker’s yeast. Surface functionality and morphology of chemically and biologically modified sorbents and biosorbents were studied by Fourier Transform Infrared analysis and scanning electron microscope imaging. Hybrid carbonaceous sorbents and biosorbents were characterized by excellent efficiency and superiority toward lead(II sorption compared to blank active carbon providing a maximum sorption capacity of lead(II ion as 500 μmol g−1. Sorption processes of lead(II by these hybrid materials were investigated under the influence of several controlling parameters such as pH, contact time, mass of sorbent and biosorbent, lead(II concentration, and foreign ions. Lead(II sorption mechanisms were found to obey the Langmuir and BET isotherm models. The potential applications of chemically and biologically modified-active carbonaceous materials for removal and extraction of lead from real water matrices were also studied via a double-stage microcolumn technique. The results of this study were found to denote to superior recovery values of lead (95.0–99.0±3.0–5.0% by various carbonaceous-modified-bakers yeast biosorbents.

  11. Functionalized Nanoporous Silica for Removal of Heavy Metals from Biological Systems; Adsorption and Application

    Energy Technology Data Exchange (ETDEWEB)

    Yantasee, Wassana; Rutledge, Ryan D.; Chouyyok, Wilaiwan; Sukwarotwat, Vichaya; Orr, Galya; Warner, Cynthia L.; Warner, Marvin G.; Fryxell, Glen E.; Wiacek, Robert J.; Timchalk, Charles; Addleman, Raymond S.


    Functionalized nanoporous silica, often referred to as self-assembled monolayers on mesoporous supports (SAMMS) have previously demonstrated the ability to serve as very effective heavy metal sorbents in a range of aquatic and environmental systems suggesting they may be advantageously utilized for biomedical applications such as chelation therapy. Herein we evaluate surface chemistries for heavy metal capture from biological fluids, various facets of the materials biocompatibility and the suitability of these materials as potential therapeutics. Of the materials tested, thiol-functionalized SAMMS proved most capable of removing selected heavy metals from biological solutions (i.e. blood, urine, etc.) As a result, thiol SAMMS was further analyzed to assess the material’s performance under a number of different biologically relevant conditions (i.e. variable pH and ionic strength) as well to gauge any potentially negative cellular effects resulting from interaction with the sorbent, such as cellular toxicity or possible chelation of essential minerals. Additionally, cellular uptake studies demonstrated no cell membrane permeation by the silica-based materials generally highlighting their ability to remain cellularly inert and thus non-toxic. As a result, it has been determined that organic ligand-functionalized nanoporous silica materials could be a valuable material for detoxification therapeutics and potentially other biomedical applications as needed.

  12. Effect of amended soil and hydraulic load on enhanced biological nitrogen removal in lab-scale SWIS. (United States)

    Zou, J L; Dai, Y; Sun, T H; Li, Y H; Li, G B; Li, Q Y


    To characterize the effect of amended soil on nitrogen removal in subsurface wastewater infiltration system (SWIS), culture, grass carbon, and zeolite were mixed to produce microbial inoculums, and then the optimal microbial inoculums, nutrient substance, cinder, and original soil were mixed to produce the soils through bioaugmentation. Results indicate that the microbial inoculums (culture+50% grass carbon+50% zeolite) and the amended soil (12.5% microbial inoculums+25% nutrient substrate+12.5% cinder+50% original soil) have the optimal biogenic stimulating properties, and the adsorption capacity of the amended soil are 1.216 mg-Pg(-1) and 0.495 mg-Ng(-1). The laboratory soil column experiment indicates that the efficient mode of nitrogen removal in lab-scale SWIS is adsorption-nitrification-denitrification and the nitrification/denitrification can be enhanced by the application of the amended soil. On average, the SWIS filled with amended soil converts 85% of ammonia nitrogen (NH(4)(+)-N) to NO(x)(-)-N and removes 49.8-60.6% of total nitrogen (TN), while the system filled with original soil removes 80% of NH(4)(+)-N and 31.3-43.2% of TN at 4-8 cm day(-1). Two systems are overloads at 10 cm day(-1). It is concluded that the microbial activities and nitrogen removal efficiencies are improved in SWIS after bioaugmentation.

  13. Long-term population dynamics and in situ physiology in activated sludge systems with enhanced biological phosphorus removal operated with and without nitrogen removal

    DEFF Research Database (Denmark)

    Lee, N.; Nielsen, P.H.; Aspegren, H.


    Quantitative fluorescence in situ hybridization (FISH) and the combination of FISH with microautoradiography (MAR) were used in order to study the long-term population dynamics (2.5 years) and the in situ physiology in two parallel activated sludge pilot systems with enhanced biological phosphorus...... removal (EBPR). The two systems received the same influent wastewater, but were differently operated (with and without nitrogen removal, respectively). Both systems showed a significant P removal that increased when different substrates (phosphorus (P), acetate and glucose, respectively) were added....... However, we observed a lower correlation (0.9). The Actinobacteria were the only additional group of bacteria which showed a similar degree of correlation to the P content in activated sludge as the Rhodocyclus-related bacteria - but only for the system without nitrogen removal. Significant amounts (less...

  14. Biofilm establishment and heavy metal removal capacity of an indigenous mining algal-microbial consortium in a photo-rotating biological contactor. (United States)

    Orandi, S; Lewis, D M; Moheimani, N R


    An indigenous mining algal-microbial consortium was immobilised within a laboratory-scale photo-rotating biological contactor (PRBC) that was used to investigate the potential for heavy metal removal from acid mine drainage (AMD). The microbial consortium, dominated by Ulothrix sp., was collected from the AMD at the Sar Cheshmeh copper mine in Iran. This paper discusses the parameters required to establish an algal-microbial biofilm used for heavy metal removal, including nutrient requirements and rotational speed. The PRBC was tested using synthesised AMD with the multi-ion and acidic composition of wastewater (containing 18 elements, and with a pH of 3.5 ± 0.5), from which the microbial consortium was collected. The biofilm was successfully developed on the PRBC's disc consortium over 60 days of batch-mode operation. The PRBC was then run continuously with a 24 h hydraulic residence time (HRT) over a ten-week period. Water analysis, performed on a weekly basis, demonstrated the ability of the algal-microbial biofilm to remove 20-50 % of the various metals in the order Cu > Ni > Mn > Zn > Sb > Se > Co > Al. These results clearly indicate the significant potential for indigenous AMD microorganisms to be exploited within a PRBC for AMD treatment.

  15. Dynamics of Intracellular Polymers in Enhanced Biological Phosphorus Removal Processes under Different Organic Carbon Concentrations

    Directory of Open Access Journals (Sweden)

    Lizhen Xing


    Full Text Available Enhanced biological phosphorus removal (EBPR may deteriorate or fail during low organic carbon loading periods. Polyphosphate accumulating organisms (PAOs in EBPR were acclimated under both high and low organic carbon conditions, and then dynamics of polymers in typical cycles, anaerobic conditions with excess organic carbons, and endogenous respiration conditions were examined. After long-term acclimation, it was found that organic loading rates did not affect the yield of PAOs and the applied low organic carbon concentrations were advantageous for the enrichment of PAOs. A low influent organic carbon concentration induced a high production of extracellular carbohydrate. During both anaerobic and aerobic endogenous respirations, when glycogen decreased to around 80 ± 10 mg C per gram of volatile suspended solids, PAOs began to utilize polyphosphate significantly. Regressed by the first-order reaction model, glycogen possessed the highest degradation rate and then was followed by polyphosphate, while biomass decay had the lowest degradation rate.

  16. The Metal And Sulphate Removal From Mine Drainage Waters By Biological-Chemical Ways

    Directory of Open Access Journals (Sweden)

    Jenčárová Jana


    Full Text Available Mine drainage waters are often characterized by high concentrations of sulphates and metals as a consequence of the mining industry of sulphide minerals. The aims of this work are to prove some biological-chemical processes utilization for the mine drainage water treatment. The studied principles of contamination elimination from these waters include sulphate reduction and metal bioprecipitation by the application of sulphate-reducing bacteria (SRB. Other studied process was metal sorption by prepared biogenic sorbent. Mine drainage waters from Slovak localities Banská Štiavnica and Smolník were used to the pollution removal examination. In Banská Štiavnica water, sulphates decreased below the legislative limit. The elimination of zinc by sorption experiments achieved 84 % and 65 %, respectively.

  17. Characteristic of COD removal and sludge settleability in biological treatment of hypersaline wastewater

    Institute of Scientific and Technical Information of China (English)

    ZHU Gui-bing; PENG Yong-zhen; MENG Xiang-sheng; CUI You-wei; SUN Ya-nan


    In order to investigate the feasibility of biological treatment of hypersaline wastewater produced from toilet flushing with seawater at low temperature, pilot-scale studies were established with plug-flow activated sludge process at low temperature (5-9℃) based on bench-scale experiments. The critical salinity concentration of 30 g/L, which resulted from the cooperation results of the non-halophilic bacteria and the halophilic bacteria, was drawn in bench-scale experiment. Pilot-scale studies showed that high COD removal efficiency, higher than 85 %, was obtained at low temperature when 30 percent seawater [ seawater/( seawater + sewage) ] was introduced. The salinity improved the settleability of activated sludge, and average SV dropped down from 38%to 22. 5% after adding seawater. Sludge bulking could be forborne effectively because filamentous bacteria couldn' t subsist under high salinity concentration.

  18. Simultaneous biological removal of endosulfan (alpha+beta) and nitrates from drinking waters using wheat straw as substrate. (United States)

    Aslan, Sükrü; Türkman, Ayşen


    Nitrate and endosulfan (alpha+beta) removal was studied in an upflow biological denitrification reactor packed with wheat straw as carbon source and support particles for microorganisms. While almost complete nitrate elimination and between 65% and 70% endosulfan (alpha+beta) elimination occurred when the temperature was higher than 20 degrees C; below that value, nitrate removal efficiency decreased to about 10%. Nitrate, dissolved organic carbon (DOC), and endosulfan (alpha+beta) removal efficiencies decreased considerably at 1500 microg/l endosulfan concentration in the batch experiments. Although a high removal efficiency was observed for endosulfan (alpha+beta) and nitrate in the biological denitrification continuous reactor, the effluent water could not be used for drinking purpose because of the unacceptable levels of endosulfan (alpha+beta), colour and dissolved organic content. During the continuous study, 23.4% of the initial weight of wheat straw was lost and 24 g was consumed per gram of nitrogen removed. The results of the continuous study showed that 21.3% of the endosulfan removal was achieved by adsorption onto the wheat straw and 68.2% of the endosulfan removal occurred by biological activity and the remaining portion was detected in the effluent water.

  19. Nutrient Regulation by Continuous Feeding Removes Limitations on Cell Yield in the Large-Scale Expansion of Mammalian Cell Spheroids


    Weegman, Bradley P; Peter Nash; Alexandra L Carlson; Kristin J Voltzke; Zhaohui Geng; Marjan Jahani; Benjamin B Becker; Papas, Klearchos K.; Firpo, Meri T.


    Cellular therapies are emerging as a standard approach for the treatment of several diseases. However, realizing the promise of cellular therapies across the full range of treatable disorders will require large-scale, controlled, reproducible culture methods. Bioreactor systems offer the scale-up and monitoring needed, but standard stirred bioreactor cultures do not allow for the real-time regulation of key nutrients in the medium. In this study, β-TC6 insulinoma cells were aggregated and cul...

  20. Enhanced Biological Phosphorus Removal in SBR Using Glucose as a Single Organic Substrate

    Institute of Scientific and Technical Information of China (English)

    JIANG Yi-feng; LI Xiang-kun; FENG Xiao-yu; WANG Shu-tao; WANG Bao-zhen; LIU Ya-nan; CHEN Jian-meng


    Enhanced biological phosphorus removal (EBPR) was investigated in an anaerobic/aerobic sequencing batch reactor (SBR) supplied with glucose as a single organic substrate. The results illustrated that EBPR process could also occur successfully with glucose other than short chain fatty acids (SCFAs). High phosphorus release and polyhydroxyalkanoate (PHA) accumulation in the anaerobic phase was found vital for the removal of phosphorus during the aerobic phase. The measurement of intracellular reserves revealed that glycogen had a higher chance to replace the energy role of poly-P under anaerobic conditions. Moreover, glycogen was also utilized as the carbon source for PHA synthesis. as well as a reducing power as reported earlier. The accumulated PHA in this system was mainly in the form of poly-hydroxyvalerate (PHV) instead of polyhydroxybutyrate (PHB), and was inferred to be caused by the excess reducing power contained in glucose. Lactate as a fermentation product was also found released into the bulk solution. Applying fundamental biochemistry knowledge to the experimental results, a conceptual biochemical model was developed to explain the metabolism of the glucoseinduced EBPR.

  1. Advances in wastewater nitrogen removal by biological processes: state of the art review

    Directory of Open Access Journals (Sweden)

    Andrea G. Capodaglio


    Full Text Available The paper summarizes the state-of-the-art of the most recent advances in biological nitrogen removal, including process design criteria and technological innovations. With reference to the Modified Ludzck Ettinger (MLE process (pre-denitrification and nitrification in the activated sludge process, the most common nitrogen removal process used nowadays, a new design equation for the denitrification reactor based on specific denitrification rate (SDNR has been proposed. In addition, factors influencing SDNR (DO in the anoxic reactor; hydrodynamic behavior are analyzed, and technological solutions are proposed. Concerning technological advances, the paper presents a summary of various “deammonification” processes, better known by their patent names like ANAMMOX®, DEMON®, CANON®, ANITA® and others. These processes have already found applications in the treatment of high-strength wastewater such as digested sludge liquor and landfill leachate. Among other emerging denitrification technologies, consideration is given to the Membrane Biofilm Reactors (MBfRs that can be operated both in oxidation and reduction mode.

  2. Metabolic versatility in full-scale wastewater treatment plants performing enhanced biological phosphorus removal. (United States)

    Lanham, Ana B; Oehmen, Adrian; Saunders, Aaron M; Carvalho, Gilda; Nielsen, Per H; Reis, Maria A M


    This study analysed the enhanced biological phosphorus removal (EBPR) microbial community and metabolic performance of five full-scale EBPR systems by using fluorescence in situ hybridisation combined with off-line batch tests fed with acetate under anaerobic-aerobic conditions. The phosphorus accumulating organisms (PAOs) in all systems were stable and showed little variability between each plant, while glycogen accumulating organisms (GAOs) were present in two of the plants. The metabolic activity of each sludge showed the frequent involvement of the anaerobic tricarboxylic acid cycle (TCA) in PAO metabolism for the anaerobic generation of reducing equivalents, in addition to the more frequently reported glycolysis pathway. Metabolic variability in the use of the two pathways was also observed, between different systems and in the same system over time. The metabolic dynamics was linked to the availability of glycogen, where a higher utilisation of the glycolysis pathway was observed in the two systems employing side-stream hydrolysis, and the TCA cycle was more active in the A(2)O systems. Full-scale plants that showed higher glycolysis activity also exhibited superior P removal performance, suggesting that promotion of the glycolysis pathway over the TCA cycle could be beneficial towards the optimisation of EBPR systems.

  3. Removal of nitrate and sulphate from biologically treated municipal wastewater by electrocoagulation (United States)

    Sharma, Arun Kumar; Chopra, A. K.


    The present investigation observed the effect of current density (j), electrocoagulation (EC) time, inter electrode distance, electrode area, initial pH and settling time on the removal of nitrate (NO3 -) and sulphate (SO4 2-) from biologically treated municipal wastewater (BTMW), and optimization of the operating conditions of the EC process. A glass chamber of two-liter volume was used for the experiments with DC power supply using two electrode plates of aluminum (Al-Al). The maximum removal of NO3 - (63.21 %) and SO4 2- (79.98 %) of BTMW was found with the optimum operating conditions: current density: 2.65 A/m2, EC time: 40 min, inter electrode distance: 0.5 cm, electrode area: 160 cm2, initial pH: 7.5 and settling time: 60 min. The EC brought down the concentration of NO3 - within desirable limit of the Bureau of Indian Standard (BIS)/WHO for drinking water. Under optimal operating conditions, the operating cost was found to be 1.01/m3 of water in terms of the electrode consumption (23.71 × 10-5 kg Al/m3) and energy consumption (101.76 kWh/m3).

  4. Integrative microbial community analysis reveals full-scale enhanced biological phosphorus removal under tropical conditions (United States)

    Law, Yingyu; Kirkegaard, Rasmus Hansen; Cokro, Angel Anisa; Liu, Xianghui; Arumugam, Krithika; Xie, Chao; Stokholm-Bjerregaard, Mikkel; Drautz-Moses, Daniela I.; Nielsen, Per Halkjær; Wuertz, Stefan; Williams, Rohan B. H.


    Management of phosphorus discharge from human waste is essential for the control of eutrophication in surface waters. Enhanced biological phosphorus removal (EBPR) is a sustainable, efficient way of removing phosphorus from waste water without employing chemical precipitation, but is assumed unachievable in tropical temperatures due to conditions that favour glycogen accumulating organisms (GAOs) over polyphosphate accumulating organisms (PAOs). Here, we show these assumptions are unfounded by studying comparative community dynamics in a full-scale plant following systematic perturbation of operational conditions, which modified community abundance, function and physicochemical state. A statistically significant increase in the relative abundance of the PAO Accumulibacter was associated with improved EBPR activity. GAO relative abundance also increased, challenging the assumption of competition. An Accumulibacter bin-genome was identified from a whole community metagenomic survey, and comparative analysis against extant Accumulibacter genomes suggests a close relationship to Type II. Analysis of the associated metatranscriptome data revealed that genes encoding proteins involved in the tricarboxylic acid cycle and glycolysis pathways were highly expressed, consistent with metabolic modelling results. Our findings show that tropical EBPR is indeed possible, highlight the translational potential of studying competition dynamics in full-scale waste water communities and carry implications for plant design in tropical regions.

  5. Enhanced primary sludge sonication by heat insulation to reclaim carbon source for biological phosphorous removal. (United States)

    Tian, Qing; Wang, Qi; Zhu, Yanbing; Li, Fang; Zhuang, Lin; Yang, Bo


    Ultrasound pretreatment is a potent step to disintegrate primary sludge (PS). The supernatant of sonicated PS is recycled as an alternative carbon source for biological phosphorus removal. In this study, we investigated the role of temperature on PS disintegration during sonication. We found that a temperature of 60°C yielded a dissolution rate of about 2% soluble chemical oxygen demand (SCOD) as compared to 7% SCOD using sonication at the specific energy (SE) of 7359kJ/kg TS. Using the SE of 6000kJ/kg TS with heat insulation during sonication, the SCOD dissolution rate of PS was similar to the result at the SE of 7051kJ/kg TS without heat insulation. Upon treatment with sonication, the PS released low concentrations of Cu and Zn into the supernatant. The phosphorus-accumulating organisms (PAOs) used the supernatant of sonicated PS as the carbon source. Supplementation with the diluted sonicated PS supernatant (SCOD≈1000mg/L) in anaerobic phase resulted in the release of phosphorus (36mg/L) and the production of polyhydroxyalkanoates (PHAs) (0.36g PHA/g SS). Compared with sodium acetate, higher polyhydroxyvalerate (PHV) faction in the polyhydroxyalkanoates (PHAs) was observed in the biomass when incubated with sonicated PS as the carbon source. This work provides a simple pathway to conserve energy and to enhance efficiencies of ultrasonic pretreatment and the recovery of carbon source from the sludge for improving the phosphorus removal in the ENR system.

  6. Biological nitrogen removal with enhanced phosphate uptake in (AO)2SBR using single sludge system

    Institute of Scientific and Technical Information of China (English)

    JIANG Yi-feng; WANG Lin; WANG Bao-zhen; HE Sheng-bing; LUI Shuo


    Simultaneous biological phosphorus and nitrogen removal with enhanced anoxic phosphate uptake via nitrite was investigated in an anaerobic-aerobic-anoxic-aerobic sequencing batch reactor((AO)2 SBR). The system showed stable phosphorus and nitrogen removal performance, and average removals for COD, TN and TP were 90%, 91% and 96%, respectively. The conditions of pH 7.5-8.0 and temperature 32℃ were found detrimental to nitrite oxidation bacteria but favorable to ammonia oxidizers, and the corresponding specific oxygen uptake rates(SOUR) for phase 1 and 2 of nitrification process were 0.7 and 15 mgO2/(gVSS·h) in respect, which led to the nitrite accumulation in aerobic phase of(AO)2 SBR. Respiratory tests showed that 40 mgNO2-N/L did not deteriorate the sludge activity drastically, and it implied that exposure of sludge to nitrite periodically enabled the biomass to have more tolerance capacity to resist the restraining effects from nitrite. In addition, batch tests were carried out and verified that denitrifying phosphorus accumulation organisms(DPAOs) could be enriched in a single sludge system coexisting with nitrifiers by introducing an anoxic phase in an anaerobic-aerobic SBR, and the ratio of the anoxic phosphate uptake capacity to aerobic phosphate uptake capacity was 45%. It was also found that nitrite(up to 20 mgNO2-N/L) was not inhibitory to anoxic phosphate uptake and could serve as an electron acceptor like nitrate, but presented poorer efficiency compared with nitrate.

  7. Performance of a novel baffled osmotic membrane bioreactor-microfiltration hybrid system under continuous operation for simultaneous nutrient removal and mitigation of brine discharge

    KAUST Repository

    Pathak, Nirenkumar


    The present study investigated the performance of an integrated osmotic and microfiltration membrane bioreactor system for wastewater treatment employing baffles in the reactor. Thus, this reactor design enables both aerobic and anoxic processes in an attempt to reduce the process footprint and energy costs associated with continuous aeration. The process performance was evaluated in terms of water flux, salinity build up in the bioreactor, organic and nutrient removal and microbial activity using synthetic reverse osmosis (RO) brine as draw solution (DS). The incorporation of MF membrane was effective in maintaining a reasonable salinity level (612-1434 mg/L) in the reactor which resulted in a much lower flux decline (i.e. 11.48 to 6.98 LMH) as compared to previous studies. The stable operation of the osmotic membrane bioreactor–forward osmosis (OMBR-FO) process resulted in an effective removal of both organic matter (97.84%) and nutrient (phosphate 87.36% and total nitrogen 94.28%), respectively.

  8. Large-scale utilization of water hyacinth for nutrient removal in Lake Dianchi in China: the effects on the water quality, macrozoobenthos and zooplankton. (United States)

    Wang, Zhi; Zhang, Zhiyong; Zhang, Junqian; Zhang, Yingying; Liu, Haiqing; Yan, Shaohua


    An ecological engineering project using water hyacinth for nutrient removal was performed in Baishan Bay of a large shallow eutrophic lake, Lake Dianchi in China. In the present study, a systematic survey of water quality, macrozoobenthos and zooplankton inside (IWH), around (AWH) and far away (FWH) water hyacinth mats was conducted in Baishan Bay from August to October 2010. The results showed that the water quality significantly improved at AWH area. Concentrations of nitrogen and phosphorus were lower and transparency was higher at AWH area than those in IWH and FWH areas. Total densities, dominant species densities, and biodiversity indexes of macrozoobenthos and cladocerans as well as copepods did not differ (P>0.05) among each other in all three areas. It was significantly (P<0.05) different for those of rotifers at IWH area compared to those in AWH and FWH areas. The results might suggest a tremendous potential for the utilization of water hyacinth in the eutrophic lake like Lake Dianchi for nutrients removal.

  9. Role of aeration intensity on performance and microbial community profiles in a sequencing batch reaction kettle (SBRK) for wastewater nutrients rapid removal. (United States)

    Xin, Xiaodong; He, Junguo; Wang, Yuefei; Feng, Jinghan; Qiu, Wei


    A lab-scale SBRK was operated to investigate the effects of aeration intensity on the system performance and microbial community dynamics within it. Results showed that the sewage nutrients was removed rapidly (just about 3-6h) with the aeration intensity increasing from 0 to 0.6MPa. Average effluent parameters were: COD below 50mg/L, NH4(+)-N less than 1mg/L, 1.5-4.5mg/L for nitrate and TP below 0.5mg/L. The highest community similarity and diversity emerged simultaneously with the aeration pressure rising from 0.2 to 0.4MPa, which was regarded as the optimal aeration intensity range. Microbial community shifted obviously and the function species of Comamonadaceae, Dechloromonas, Flavobacterium and Nitrospira dominated in the corresponding communities. RDA indicated that aeration intensity was the main factor for regulating system communities to optimize the system performance. It inferred that high aeration pressure played a key role on sewage nutrients rapid removal.

  10. Removing constraints on the biomass production of freshwater macroalgae by manipulating water exchange to manage nutrient flux.

    Directory of Open Access Journals (Sweden)

    Andrew J Cole

    Full Text Available Freshwater macroalgae represent a largely overlooked group of phototrophic organisms that could play an important role within an industrial ecology context in both utilising waste nutrients and water and supplying biomass for animal feeds and renewable chemicals and fuels. This study used water from the intensive aquaculture of freshwater fish (Barramundi to examine how the biomass production rate and protein content of the freshwater macroalga Oedogonium responds to increasing the flux of nutrients and carbon, by either increasing water exchange rates or through the addition of supplementary nitrogen and CO2. Biomass production rates were highest at low flow rates (0.1-1 using raw pond water. The addition of CO2 to cultures increased biomass production rates by between 2 and 25% with this effect strongest at low water exchange rates. Paradoxically, the addition of nitrogen to cultures decreased productivity, especially at low water exchange rates. The optimal culture of Oedogonium occurred at flow rates of between 0.5-1, where uptake rates peaked at 1.09 for nitrogen and 0.13 for phosphorous. At these flow rates Oedogonium biomass had uptake efficiencies of 75.2% for nitrogen and 22.1% for phosphorous. In this study a nitrogen flux of 1.45 and a phosphorous flux of 0.6 was the minimum required to maintain the growth of Oedogonium at 16-17 g and a crude protein content of 25%. A simple model of minimum inputs shows that for every gram of dry weight biomass production (g, Oedogonium requires 0.09 of nitrogen and 0.04 of phosphorous to maintain growth without nutrient limitation whilst simultaneously maintaining a high-nutrient uptake rate and efficiency. As such the integrated culture of freshwater macroalgae with aquaculture for the purposes of nutrient recovery is a feasible solution for the bioremediation of wastewater and the

  11. Removing constraints on the biomass production of freshwater macroalgae by manipulating water exchange to manage nutrient flux. (United States)

    Cole, Andrew J; de Nys, Rocky; Paul, Nicholas A


    Freshwater macroalgae represent a largely overlooked group of phototrophic organisms that could play an important role within an industrial ecology context in both utilising waste nutrients and water and supplying biomass for animal feeds and renewable chemicals and fuels. This study used water from the intensive aquaculture of freshwater fish (Barramundi) to examine how the biomass production rate and protein content of the freshwater macroalga Oedogonium responds to increasing the flux of nutrients and carbon, by either increasing water exchange rates or through the addition of supplementary nitrogen and CO2. Biomass production rates were highest at low flow rates (0.1-1 using raw pond water. The addition of CO2 to cultures increased biomass production rates by between 2 and 25% with this effect strongest at low water exchange rates. Paradoxically, the addition of nitrogen to cultures decreased productivity, especially at low water exchange rates. The optimal culture of Oedogonium occurred at flow rates of between 0.5-1, where uptake rates peaked at 1.09 for nitrogen and 0.13 for phosphorous. At these flow rates Oedogonium biomass had uptake efficiencies of 75.2% for nitrogen and 22.1% for phosphorous. In this study a nitrogen flux of 1.45 and a phosphorous flux of 0.6 was the minimum required to maintain the growth of Oedogonium at 16-17 g and a crude protein content of 25%. A simple model of minimum inputs shows that for every gram of dry weight biomass production (g, Oedogonium requires 0.09 of nitrogen and 0.04 of phosphorous to maintain growth without nutrient limitation whilst simultaneously maintaining a high-nutrient uptake rate and efficiency. As such the integrated culture of freshwater macroalgae with aquaculture for the purposes of nutrient recovery is a feasible solution for the bioremediation of wastewater and the supply of a

  12. Remediation of Urban River Water by Pontederia Cordata Combined with Artificial Aeration: Organic Matter and Nutrients Removal and Root-Adhered Bacterial Communities. (United States)

    Gu, Dungang; Xu, Huan; He, Yan; Zhao, Feng; Huang, Minsheng


    Macrophyte combined with artificial aeration is a promising in situ remediation approach for urban rivers polluted with nutrients and organic matter. However, seasonal variations and aeration effects on phytoremediation performance and root-adhered microbial communities are still unclear. In this study, Pontederia cordata was used to treat polluted urban river water under various aeration intensities. Results showed that the highest removal efficiencies of chemical oxygen demand (COD(Cr)) and total nitrogen (TN) were attained under aeration of 30 L min(-1) in spring and summer and 15 L min(-1) in autumn, while total phosphorus (TP) removal reached maximum with aeration of 15 L min(-1) in all seasons. Moderate aeration was beneficial for increasing the diversity of root-adhered bacteria communities, and the shift of bacterial community structure was more pronounced in spring and autumn with varying aeration intensity. The dual effect, i.e. turbulence and dissolved oxygen (DO), of aeration on the removal of COD(Cr) and TN prevailed over the individual effect of DO, while DO was the most influential factor for TP removal and the root-adhered bacterial community diversity. P. cordata combined with 15 L min(-1) aeration was deemed to be the best condition tested in this study.

  13. Biological removal of iron and manganese in rapid sand filters - Process understanding of iron and manganese removal

    DEFF Research Database (Denmark)

    Lin, Katie

    .g. flocculation) and physical (e.g. membrane filtration) based technologies. The removal of dissolved manganese and iron is important. If manganese and iron enter the distribution system, the water will become coloured and have a metallic taste, and it may cause problems in the distribution network due......In Denmark and many other European countries, drinking water is exclusively or mainly based on groundwater. Treatment of the groundwater is rather simple, only including aeration and a subsequent filtration process. The filtration process may take place over to steps. Step 1: Filtration in a pre......-filter, where iron is removed. Step 2: Filtration in an after-filter where e.g. ammonium and manganese is removed. The treatment relies on microbial processes and may present an alternative, greener and more sustainable approach for drinking water production spending less chemicals and energy than chemical (e...

  14. Effective Biological Nitrogen Removal Treatment Processes for Domestic Wastewaters with Low C/N Ratios: A Review

    DEFF Research Database (Denmark)

    Sun, Sheng-Peng; Pellicer i Nàcher, Carles; Merkey, Brian


    Discharge of nitrogenous components to water bodies can cause eutrophication, deterioration of water quality, toxicity to aquatic life, and pose a potential hazard to human and animal health. Biological nitrogen removal can remove nitrogenous components via conversion to harmless nitrogen gas...... with high efficiency and relative low costs. However, the removal of nitrogen from domestic wastewater with a low carbon/nitrogen (C/N) ratio can often be limited in municipal wastewater plants (WWTPs) because organic carbon is a limiting factor for denitrification. The present work reviews innovative...... treatment processes including the modified anaerobic/anoxic/oxic (A(2)/O) process, the step-feed multistage anaerobic/ oxic (A/O) process, and new reactors like the membrane bioreactors (MBRs) and the membrane-aerated biofilm reactors (MABRs) can support the innovative biological nitrogen removal pathways...

  15. Study on biological phosphorus removal process by Acinetobacter lwoffi: possibility to by-pass the anaerobic phase

    Energy Technology Data Exchange (ETDEWEB)

    Ghigliazza, R.; Lodi, A.; Rovatti, M. [Institute of Chemical and Process Engineering ``G.B. Bonino``, University of Genoa (Italy)


    An Acinetobacter lwoffi culture has been submitted to anaerobic/aerobic conditions in a Sequencing Batch Reactor (SBR) in order to study the ability of this strain in biological phosphorus removal process. Even by feeding a pure sodium acetate substrate, no phosphorus release has been detected during anaerobiosis, while phosphorus uptake beyond metabolic needs has been recorded during the aerobic phase; the anaerobic phase seems to have no influence on the enhanced biological phosphorus removal mechanisms. Hence aerobic batch tests have been carried out in order to verify the ability of Acinetobacter lwoffi to remove phosphorus by ``luxury uptake`` and ``overplus accumulation`` without anaerobic stress. Obtained results revealed a phosphorus removal efficiency of 75-80%. (orig.) With 5 figs., 3 tabs., 18 refs.


    Directory of Open Access Journals (Sweden)

    Fabiano de Carvalho Balieiro


    Full Text Available Pseudosamanea guachapele (guachapele, a nitrogen fixing leguminous tree, is an alternative for mixed forest plantations in the tropics. As little information is available for guachapele (Mimosoideae in mixed plantation with eucalyptus considering the Brazilian edaphoclimatic conditions, an experiment was carried out to evaluate the contribution of biological nitrogen fixation to guachapele and leaf litter decomposition rates and nutrient release of eucalyptus and guachapele residues (pure and mixed. The percentage of nitrogen derived from atmospheric N2 (% Ndfa was estimated by comparing the natural 15N abundance (15N, ‰ in guachapele tissues with that of Eucalyptus grandis, a non-nitrogen fixing species, both with seven years after planting. Decomposition constants (k and litter half-lives (t1/2 were estimated by fitting a single exponential model to litter bag data. The estimation of %Ndfa for guachapele in pure stand fell within a narrower range (17-36 % in relation to mixed conditions (35-60 %. Nitrogen concentration in leaf litter was positively related to the decomposition rate, decreasing from pure guachapele to pure eucalyptus. Half-lives (t1/2 were significantly different (p < 0.05 among residues with 148, 185 and 218 days, for guachapele leaves, mixture of both species and for pure eucalyptus, respectively. Nutrient release rates followed the same sequence of t1/2 due to the initial residues quality (mainly N. It was observed that a fast release of N, K and Mg occurred from the residues tested, mainly for guachapele and mixed stand. These results indicate that guachapele could benefit the mixed system from the N addition and a faster decomposition rate of a richer litter.

  17. COD, nutrient removal and disinfection efficiency of a combined subsurface and surface flow constructed wetland: A case study. (United States)

    Sartori, Laura; Canobbio, Sergio; Fornaroli, Riccardo; Cabrini, Riccardo; Marazzi, Francesca; Mezzanotte, Valeria


    A constructed wetland system composed of a subsurface flow wetland, a surface flow wetland and a facultative pond was studied from July 2008 until May 2012. It was created to treat the domestic sewage produced by a hamlet of 150 inhabitants. Monthly physicochemical and microbiological analyses were carried out in order to evaluate the removal efficiency of each stage of the process and of the total treatment system. Pair-wise Student's t-tests showed that the mean removal of each considered parameter was significantly different (α = 0.05) between the various treatment phases. Two-way ANOVA and Tukey's HSD tests were used to find significant differences between wetland types and seasons in the removal efficiency of the considered water quality parameters. Significant differences in percent removal efficiency between the treatment phases were observed for total phosphorus, total nitrogen, ammonia nitrogen and organic load (expressed as Chemical Oxygen Demand). In general, the wastewater treatment was carried by the sub-superficial flow phase mainly, both in growing season and in quiescence season. Escherichia coli removal ranged from 98% in quiescence season to >99% in growing season (approximately 2-3 orders of magnitude). The inactivation of fecal bacteria was not influenced by the season, but only by the treatment phase.

  18. Biological processes for environmental control of effluent streams in the nuclear fuel cycle. [Denitrification; removal of heavy metals

    Energy Technology Data Exchange (ETDEWEB)

    Shumate, II, S E; Hancher, C W; Strandberg, G W; Scott, C D


    Nitrates and radioactive heavy metals need to be removed from aqueous effluent streams in the fuel cycle. Biological methods are being developed for reducing nitrate or nitrite to N/sub 2/ gas and for decreasing dissolved metal concentration to less than 1 g/m/sup 3/. Fluidized-bed denitrification bioreactors are being tested. Removal of uranium from solution by Saccharomyces cerevisiae and Pseudomonas aeruginosa was studied. (DLC)

  19. Recovery and removal of nutrients from swine wastewater by using a novel integrated reactor for struvite decomposition and recycling. (United States)

    Huang, Haiming; Xiao, Dean; Liu, Jiahui; Hou, Li; Ding, Li


    In the present study, struvite decomposition was performed by air stripping for ammonia release and a novel integrated reactor was designed for the simultaneous removal and recovery of total ammonia-nitrogen (TAN) and total orthophosphate (PT) from swine wastewater by internal struvite recycling. Decomposition of struvite by air stripping was found to be feasible. Without supplementation with additional magnesium and phosphate sources, the removal ratio of TAN from synthetic wastewater was maintained at >80% by recycling of the struvite decomposition product formed under optimal conditions, six times. Continuous operation of the integrated reactor indicated that approximately 91% TAN and 97% PT in the swine wastewater could be removed and recovered by the proposed recycling process with the supplementation of bittern. Economic evaluation of the proposed system showed that struvite precipitation cost can be saved by approximately 54% by adopting the proposed recycling process in comparison with no recycling method.

  20. Membrane bioreactor and nanofiltration hybrid system for reclamation of municipal wastewater: removal of nutrients, organic matter and micropollutants. (United States)

    Chon, Kangmin; KyongShon, Ho; Cho, Jaeweon


    A membrane bioreactor (MBR) and nanofiltration (NF) hybrid system was investigated to demonstrate the performance of treating nitrogen, phosphorus and pharmaceuticals and personal care products (PPCPs) in municipal wastewater. With the MBR and NF (molecular weight cut off (MWCO): 210 Da), the concentration of total nitrogen (TN) and total phosphorus (TP) was effectively reduced by nitrification by MBR and negatively charged surface of NF (TN: 8.67 mgN/L and TP: 0.46 mgP/L). Biosorption and microbial decomposition in MBR seem to be major removal mechanisms for the removal of PPCPs. Among various parameters affecting the removal of PPCPs by NF, namely, physicochemical properties of the PPCPs (charge characteristics, hydrophobicity and M(W)) and membranes (MWCO and surface charge), the MWCO effect was found to be the most critical aspect.

  1. Growth and nutrient removal in free and immobilized green algae in batch and semi-continuous cultures treating real wastewater. (United States)

    Ruiz-Marin, Alejandro; Mendoza-Espinosa, Leopoldo G; Stephenson, Tom


    Two species of microalgae growing as immobilized and free-cells were compared to test its ability to remove N and P in batch cultures of urban wastewater. The best microalgae-cell growth configuration was selected to be tested in bioreactor operated in semi-continuous mode. Scenedesmus obliquus showed a higher N and P uptake rate in urban wastewater than Chlorella vulgaris. When tested in semi-continuous mode and with the re-calcification of beads, S. obliquus was more effective in removing N and P for longer periods (181 h) than batch cultures; fecal coliforms removal was good (95%) although the final concentration was still unsuitable for discharge to natural water bodies. Protein and lipids content analysis suggest that, from a practical point of view, immobilized systems could facilitate the separation of the biomass from the treated wastewater although in terms of nutritional value of the biomass, immobilized systems do not represent an advantage over free-cell systems.

  2. Seasonal nutrient and plankton dynamics in a physical-biological model of Crater Lake (United States)

    Fennel, K.; Collier, R.; Larson, G.; Crawford, G.; Boss, E.


    A coupled 1D physical-biological model of Crater Lake is presented. The model simulates the seasonal evolution of two functional phytoplankton groups, total chlorophyll, and zooplankton in good quantitative agreement with observations from a 10-year monitoring study. During the stratified period in summer and early fall the model displays a marked vertical structure: the phytoplankton biomass of the functional group 1, which represents diatoms and dinoflagellates, has its highest concentration in the upper 40 m; the phytoplankton biomass of group 2, which represents chlorophyta, chrysophyta, cryptomonads and cyanobacteria, has its highest concentrations between 50 and 80 m, and phytoplankton chlorophyll has its maximum at 120 m depth. A similar vertical structure is a reoccurring feature in the available data. In the model the key process allowing a vertical separation between biomass and chlorophyll is photoacclimation. Vertical light attenuation (i.e., water clarity) and the physiological ability of phytoplankton to increase their cellular chlorophyll-to-biomass ratio are ultimately determining the location of the chlorophyll maximum. The location of the particle maxima on the other hand is determined by the balance between growth and losses and occurs where growth and losses equal. The vertical particle flux simulated by our model agrees well with flux measurements from a sediment trap. This motivated us to revisit a previously published study by Dymond et al. (1996). Dymond et al. used a box model to estimate the vertical particle flux and found a discrepancy by a factor 2.5-10 between their model-derived flux and measured fluxes from a sediment trap. Their box model neglected the exchange flux of dissolved and suspended organic matter, which, as our model and available data suggests is significant for the vertical exchange of nitrogen. Adjustment of Dymond et al.'s assumptions to account for dissolved and suspended nitrogen yields a flux estimate that is

  3. Nutrient Removal and Biomass Production in an Outdoor Pilot-Scale Phototrophic Biofilm Reactor for Effluent Polishing

    NARCIS (Netherlands)

    Boelee, N.C.; Janssen, M.; Temmink, H.; Shrestha, R.; Buisman, C.J.N.; Wijffels, R.H.


    An innovative pilot-scale phototrophic biofilm reactor was evaluated over a 5-month period to determine its capacity to remove nitrogen and phosphorus from Dutch municipal wastewater effluents. The areal biomass production rate ranged between 2.7 and 4.5 g dry weight/m2/day. The areal nitrogen and p

  4. Nutrient removal of a floating plant system receiving low- pollution wastewater: Effects of plant species and influent concentration (United States)

    Duan, J. J.; Zhao, J. N.; Xue, L. H.; Yang, L. Z.


    Plant floating bed was adopted in this study to compare the purification effect of four plant species (Oenanthe javanica, Ipomoea aquatica, Hydrocotyle vulgaris, and Iris sibirica) receiving high and low treated domestic sewage. The experiment was conducted for eight months during the low temperature season. The results indicated that the average removal rates of TN and NH4+-N in I. aquatica floating bed were relatively high both under high and low influent concentration during the first stage of the experiment. During the second stage, H. vulgaris showed the best performance for nitrogen treatment, and the average removal rates of TN were 70.7% and 87.7% under high and low influent concentration, while the average removal rates of NH4 +-N were as high as 98.9% and 98.9%, accordingly. Moreover, H. vulgaris contributed most for plant assimilation to nitrogen removal among different plant floating systems. It was also found that the existence of hydrophytes effectively controlled the rise of water pH value and algae growth and reproduction, which helped to improve the aquatic environment. The results provide engineering parameters for the future design of an ecological remediation technology for low-pollution wastewater purification.

  5. Growth and nutrient removal of three macrophytes in response to concentrations and ratios of N and P. (United States)

    Liao, JianXiong; Zhang, DeNan; Mallik, Azim; Huang, YuQing; He, ChengXin; Xu, GuangPing


    Wastewater from different sources show great differences in concentrations and ratios of N and P. In order to choose suitable plant species to remove excess N and/or P from polluted waters, it is important to know the performances of these plants under different N and P concentrations. In this study, we investigated the growth and N and P removal of three macrophytes, Coix lacryma-jobi, Iris wilsonii and Arundo donax under six N and P combination treatments. C. lacryma-jobi preferred higher N and P concentrations (16 mg N L(-1) and 3.2 mg P L(-1)), and increasing N supply could increase its P removal rate. I. wilsonii exhibited a growth preference at a combination of moderate N and P concentrations (8 mg N L(-1) and 0.8 mg P L(-1)). A. donax could grow well at all combinations of N and P and had significantly higher relative growth rate (RGR) and N and P removal rates than the other two species. These results showed A. donax is a promising species to treat various polluted waters and the other two species can be used specifically to treat certain types of wastewater.

  6. Evaluation of the treatment performance of lab-scaled vertical flow constructed wetlands in removal of organic compounds, color and nutrients in azo dye-containing wastewater. (United States)

    Dogdu, Gamze; Yalcuk, Arda


    The objective of this study is to examine the treatment performance of vertical flow intermittent feeding constructed wetland (VFCW) in removal of organic pollution, nutrients and color in azo-dye containing wastewater. The systems consisted of PVC reactors, some filling materials such as gravel, sand and zeolite and wetland plants including Typha angustifolia and Canna indica. The average treatment efficiency of the systems for COD, color, sulphate, NH4-N, and PO4-P were in the range of 57-63%, 94-99%, 44-48%, 39-44%, and 84-88%, respectively among the VFCW reactors. It is concluded that VFCW reactor system can effectively be used in the treatment of dye-rich wastewater, especially for the removal of color and in the reduction of COD. Biofilm formation and cleavage of azo bonds could be observed by SEM and FTIR results, respectively. Almost similar NH4-N and PO4-P removal were obtained in all reactors by using same amount of zeolite media.

  7. Enhancement of Nutrient Removal in a Hybrid Constructed Wetland Utilizing an Electric Fan Air Blower with Renewable Energy of Solar and Wind Power

    Directory of Open Access Journals (Sweden)

    Dong Jin Lee


    Full Text Available The sewage treatment efficiency of hybrid constructed wetlands (CWs was evaluated under different ventilation methods. The removal efficiencies of biochemical oxygen demand (BOD, total nitrogen (TN, and total phosphorus (TP in the vertical flow- (VF- horizontal flow (HF CWs using an electric fan air blower by the renewable energy of solar and wind power were higher than those by natural ventilation, excluding only suspended solids (SS. The TN treatment efficiency in the CW using the air blower especially increased rapidly by 16.6% in comparison with the CW employing natural ventilation, since the VF bed provided suitable conditions (aerobic for nitrification to occur. The average removal efficiencies of BOD, SS, TN, and TP in the effluent were 98.8, 97.4, 58.0, and 48.3% in the CW using an electric fan air blower, respectively. The treatment performance of the CWs under different ventilation methods was assessed, showing TN in the CW using an electric fan air blower to be reduced by 57.5~58.6% for inlet TN loading, whereas reduction by 19.0~53.3% was observed in the CW with natural ventilation. Therefore, to increase the removal of nutrients in CWs, an improved ventilation system, providing ventilation via an electric fan air blower with the renewable energy, is recommended.

  8. Nutrients removal and lipids production by Chlorella pyrenoidosa cultivation using anaerobic digested starch wastewater and alcohol wastewater. (United States)

    Yang, Libin; Tan, Xiaobo; Li, Deyi; Chu, Huaqiang; Zhou, Xuefei; Zhang, Yalei; Yu, Hong


    The cultivation of microalgae Chlorella pyrenoidosa (C. pyrenoidosa) using anaerobic digested starch wastewater (ADSW) and alcohol wastewater (AW) was evaluated in this study. Different proportions of mixed wastewater (AW/ADSW=0.176:1, 0.053:1, 0.026:1, v/v) and pure ADSW, AW were used for C. pyrenoidosa cultivation. The different proportions between ADSW and AW significantly influenced biomass growth, lipids production and pollutants removal. The best performance was achieved using mixed wastewater (AW/ADSW=0.053:1, v/v), leading to a maximal total biomass of 3.01±0.15 g/L (dry weight), lipids productivity of 127.71±6.31 mg/L/d and pollutants removal of COD=75.78±3.76%, TN=91.64±4.58% and TP=90.74±4.62%.

  9. Removal of nutrients from combined sewer overflows and lake water in a vertical-flow constructed wetland system. (United States)

    Gervin, L; Brix, H


    Lake Utterslev is situated in a densely built-up area of Copenhagen, and is heavily eutrophicated from combined sewer overflows. At the same time the lake suffers from lack of water. Therefore, a 5,000 m2 vertical flow wetland system was constructed in 1998 to reduce the phosphorus discharge from combined sewer overflows without reducing the water supply to the lake. During dry periods the constructed wetland is used to remove phosphorus from the lake water. The system is designed as a 90 m diameter circular bed with a bed depth of c. 2 m. The system is isolated from the surroundings by a polyethylene membrane. The bed medium consists of a mixture of gravel and crushed marble, which has a high binding capacity for phosphorus. The bed is located within the natural littoral zone of the lake and is planted with common reed (Phragmites australis). The constructed wetland is intermittently loaded with combined sewer overflow water or lake water and, after percolation through the bed medium, the water is collected in a network of drainage pipes at the bottom of the bed and pumped to the lake. The fully automated loading cycle results in alternating wet and dry periods. During the initial two years of operation, the phosphorus removal for combined sewer overflows has been consistently high (94-99% of inflow concentrations). When loaded with lake water, the phosphorus removal has been high during summer (71-97%) and lower during winter (53-75%) partly because of lower inlet concentrations. Effluent phosphorus concentrations are consistently low (0.03-0.04 mg/L). Ammonium nitrogen is nitrified in the constructed wetland, and total suspended solids and COD are generally reduced to concentrations below 5 mg/L and 25 mg/L, respectively. The study documents that a subsurface flow constructed wetland system can be designed and operated to effectively remove phosphorus and other pollutants from combined sewer overflows and eutrophicated lake water.

  10. The effect of amino acids on lipid production and nutrient removal by Rhodotorula glutinis cultivation in starch wastewater. (United States)

    Liu, Meng; Zhang, Xu; Tan, Tianwei


    In this paper, the components of amino acids in mixed starch wastewater (corn steep water/corn gluten water=1/3, v/v) were analyzed by GC-MS. Effects of amino acids on lipid production by Rhodotorula glutinis and COD removal were studied. The results showed that mixed starch wastewater contained 9 kinds of amino acids and these amino acids significantly improved the biomass (13.63g/L), lipid yield (2.48g/L) and COD removal compared to the basic medium (6.23g/L and 1.56g/L). In a 5L fermentor containing mixed starch wastewater as substrate to culture R. glutinis, the maximum biomass, lipid content and lipid yield reached 26.38g/L, 28.90% and 7.62g/L, with the associated removal rates of COD, TN and TP reaching 77.41%, 69.12% and 73.85%, respectively. The results revealed a promising approach for lipid production with using amino acids present in starch wastewater as an alternative nitrogen source.

  11. Composição mineral de frutos cítricos na colheita Mineral nutrient removal by the harvest of citrus fruit

    Directory of Open Access Journals (Sweden)

    Ondino C. Bataglia


    fruits were sectioned in skin, pulp with juice, and seeds. It was determined the proportion among these parte and their water content. The concentration of all plant nutriente plus sodium, aluminum and cobalt was determined on the dried material. These data allowed the estimation of nutrient removal per metric ton of fresh fruit. The average of removed elements expressed in gramms per ton of fresh fruit of the nine cultivars follows this order: N-1,906; P-173; K-1,513; Ca-526; Mg-127; S-137; B-2.2; Cl-24.7; Cu-1.2; Fe-6.6; Mn-2.8; Mo-0.008; Zn-0.9; Co-0.003; Na-43.5; Al-7.6. The seeds showed to be organs where there is larger percentual quantity of the majority of macronutrients, except for K which is more abundant in the pulp plus juice. The cultivars Natal and Valencia showed the greatest nutrient removal, and Tahiti lime the lowest.

  12. In situ identification of polyphosphate- and polyhydroxyalkanoate-accumulating traits for microbial populations in a biological phosphorus removal process

    DEFF Research Database (Denmark)

    Liu, W.-T.; Nielsen, Alex Toftgaard; Wu, JH


    Polyphosphate- and polyhydroxyalkanoate (PHA)- accumulating traits of predominant microorganisms in an efficient enhanced biological phosphorus removal (EBPR) process were investigated systematically using a suite of non-culture-dependent methods. Results of 16S rDNA clone library and fluorescence...

  13. Removal of Refractory Organics from Biologically Treated Landfill Leachate by Microwave Discharge Electrodeless Lamp Assisted Fenton Process

    Directory of Open Access Journals (Sweden)

    Jiuyi Li


    Full Text Available Biologically treated leachate usually contains considerable amount of refractory organics and trace concentrations of xenobiotic pollutants. Removal of refractory organics from biologically treated landfill leachate by a novel microwave discharge electrodeless lamp (MDEL assisted Fenton process was investigated in the present study in comparison to conventional Fenton and ultraviolet Fenton processes. Conventional Fenton and ultraviolet Fenton processes could substantially remove up to 70% of the refractory organics in a membrane bioreactor treated leachate. MDEL assisted Fenton process achieved excellent removal performance of the refractory components, and the effluent chemical oxygen demand concentration was lower than 100 mg L−1. Most organic matters were transformed into smaller compounds with molecular weights less than 1000 Da. Ten different polycyclic aromatic hydrocarbons were detected in the biologically treated leachate, most of which were effectively removed by MDEL-Fenton treatment. MDEL-Fenton process provides powerful capability in degradation of refractory and xenobiotic organic pollutants in landfill leachate and could be adopted as a single-stage polishing process for biologically treated landfill leachate to meet the stringent discharge limit.

  14. Biological wastewater treatment followed by physicochemical treatment for the removal of fluorinated surfactants. (United States)

    Schröder, H F R; José, H J; Gebhardt, W; Moreira, R F P M; Pinnekamp, J


    Perfluorinated surfactants (PFS) have become compounds of high concern during the last decade. While "conventional surfactants" are degraded to a great extent in the biological wastewater treatment process, partly or perfluorinated surfactants are not only stable against biodegradation but also against oxidizing agents, they even resist OH-radical attacks. Our objectives were to eliminate the fluorinated surfactants perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) by adsorption, separation or degradation with a balance of precursor compounds and follow-up of degradation products. Therefore, municipal wastewater was spiked with these fluorinated surfactants before membrane bioreactor (MBR) treatment-applying microfiltration membranes--was performed and before permeates were treated using ozone (O3) or different advanced oxidation treatment (AOP) techniques. O3 or hydrogen peroxide (H2O2), both in combination with UV radiation or in combination with catalysts, was applied. Removal by adsorption or membrane separation as well as degradation were monitored by substance specific determination and identification. High resolution mass spectrometry after high performance liquid chromatography (HPLC/HRMS and -MS(n)) was used for analysis. Contact to Teflon and/or glass during all analytical procedures was avoided.

  15. Effect of salinity on N₂O production during shortcut biological nitrogen removal from landfill leachate. (United States)

    Liu, Mu; Liu, Tiantian; Peng, Yongzhen; Wang, Shuying; Xiao, Han


    Three identical SBR adapted to different salinity were applied to investigate the characteristics of the treatment performance and N2O production [Formula: see text] during shortcut biological nitrogen removal from landfill leachate under various operating parameters. Increase of salinity might deteriorate the activity of the microorganisms leading to the increase of [Formula: see text] , however, the system could be gradually adapted to the inhibition and alleviate the detrimental effect to some extent. The system acclimated to high salinity provided better performance under high salinity shock and a lower possibility of [Formula: see text] , while a sudden decrease in salinity can cause a temporary increase in [Formula: see text] . High salinity strengthened the influence of high ammonia nitrogen concentration and low DO concentration on [Formula: see text] while the strengthening effect was unconspicuous at high DO concentration. The anoxic phase did not produce a significant amount of N2O even at the lowest C/N ratio of 0.5 and was less susceptible to salinity. Characterization of the biomass composition using fluorescence in situ hybridization analysis confirmed that the relative proportion of Nitrosomonas europaea was increased with the increase of the salinity, which may be an important factor for the strengthening effect of salinity on [Formula: see text] .

  16. Chemically and biologically modified activated carbon sorbents for the removal of lead ions from aqueous media. (United States)

    Mahmoud, Mohamed E; Abdel-Fattah, Tarek M; Osman, Maher M; Ahmed, Somia B


    A method is described for hybridization of the adsorption and biosorption characteristics of chemically treated commercial activated carbon and baker's yeast, respectively, for the formation of environmental friendly multifunctional sorbents. Activated carbon was loaded with baker's yeast after acid-base treatment. Scanning Electron Microscopy (SEM) and Fourier Transform Infrared (FTIR) Spectroscopy were used to characterize these sorbents. Moreover, the sorption capabilities for lead (II) ions were evaluated. A value of 90 μmol g(-1) was identified as the maximum sorption capacity of activated carbon. Acid-base treatment of activated carbon was found to double the sorption capacity (140-180 μmol g(-1)). Immobilization of baker's yeast on the surface of activated carbon sorbents was found to further improve the sorption capacity efficiency of lead to 360, 510 and 560 μmol g(-1), respectively. Several important factors such as pH, contact time, sorbent dose, lead concentration and interfering ions were examined. Lead sorption process was studied and evaluated by several adsorption isotherms and found to follow the Langmuir and BET models. The potential applications of various chemically and biologically modified sorbents and biosorbents for removal of lead from real water matrices were also investigated via multistage micro-column technique and the results referred to excellent recovery values of lead (95.0-99.0 ± 3.0-5.0 %).

  17. Continuous biological waste gas treatment in stirred trickle-bed reactor with discontinuous removal of biomass. (United States)

    Laurenzis, A; Heits, H; Wübker, S; Heinze, U; Friedrich, C; Werner, U


    A new reactor for biological waste gas treatment was developed to eliminate continuous solvents from waste gases. A trickle-bed reactor was chosen with discontinuous movement of the packed bed and intermittent percolation. The reactor was operated with toluene as the solvent and an optimum average biomass concentration of between 5 and 30 kg dry cell weight per cubic meter packed bed (m3pb). This biomass concentration resulted in a high volumetric degradation rate. Reduction of surplus biomass by stirring and trickling caused a prolonged service life and prevented clogging of the trickle bed and a pressure drop increase. The pressure drop after biomass reduction was almost identical to the theoretical pressure drop as calculated for the irregular packed bed without biomass. The reduction in biomass and intermittent percolation of mineral medium resulted in high volumetric degradation rates of about 100 g of toluene m-3pb h-1 at a load of 150 g of toluene m-3pb h-1. Such a removal rate with a trickle-bed reactor was not reported before.

  18. Sequential ozone advanced oxidation and biological oxidation processes to remove selected pharmaceutical contaminants from an urban wastewater. (United States)

    Espejo, Azahara; Aguinaco, Almudena; García-Araya, J F; Beltrán, Fernando J


    Sequential treatments consisting in a chemical process followed by a conventional biological treatment, have been applied to remove mixtures of nine contaminants of pharmaceutical type spiked in a primary sedimentation effluent of a municipal wastewater. Combinations of ozone, UVA black light (BL) and Fe(III) or Fe₃O₄ catalysts constituted the chemical systems. Regardless of the Advanced Oxidation Process (AOP), the removal of pharmaceutical compounds was achieved in 1 h of reaction, while total organic carbon (TOC) only diminished between 3.4 and 6%. Among selected ozonation systems to be implemented before the biological treatment, the application of ozone alone in the pre-treatment stage is recommended due to the increase of the biodegradability observed. The application of ozone followed by the conventional biological treatment leads high TOC and COD removal rates, 60 and 61%, respectively, and allows the subsequent biological treatment works with shorter hydraulic residence time (HRT). Moreover, the influence of the application of AOPs before and after a conventional biological process was compared, concluding that the decision to take depends on the characterization of the initial wastewater with pharmaceutical compounds.

  19. Cost-performance analysis of nutrient removal in a full-scale oxidation ditch process based on kinetic modeling

    Institute of Scientific and Technical Information of China (English)

    Zheng Li; Rong Qi; Bo Wang; Zhe Zou; Guohong Wei; Min Yang


    A full-scale oxidation ditch process for treating sewage was simulated with the ASM2d model and optimized for minimal cost with acceptable performance in terms of ammonium and phosphorus removal.A unified index was introduced by integrating operational costs (aeration energy and sludge production) with effluent violations for performance evaluation.Scenario analysis showed that,in comparison with the baseline (all of the 9 aerators activated),the strategy of activating 5 aerators could save aeration energy significantly with an ammonium violation below 10%.Sludge discharge scenario analysis showed that a sludge discharge flow of 250-300 m3/day (solid retention time (SRT),13-15 days) was appropriate for the enhancement of phosphorus removal without excessive sludge production.The proposed optimal control strategy was:activating 5 rotating disks operated with a mode of "111100100" ("1"represents activation and "0" represents inactivation) for aeration and sludge discharge flow of 200 m3/day (SRT,19 days).Compared with the baseline,this strategy could achieve ammonium violation below 10% and TP violation below 30% with substantial reduction of aeration energy cost (46%) and minimal increment of sludge production (< 2%).This study provides a useful approach for the optimization of process operation and control.

  20. [Development of a novel hybrid UAFB-anoxic-aerobic MBR for energy production and nutrients removal from domestic wastewater]. (United States)

    Gao, Da-wen; An, Rui; Fu, Yuan; Ren, Nan-qi


    The combined treatment process making up of up-flow anaerobic sludge fixed bed (UAFB), anoxic tank and aerobic membrane bioreactor (MBR) was used to treat domestic wastewater. And the ability of reclaiming methane and reusing wastewater was investigated. The efficiency of the combined treatment process treating wastewater at optimized parameters was studied in this paper. The combined treatment process treating domestic wastewater run at optimized parameters (20 degrees C, HRT were 3 h, 3 h, 3.5 h) indicated that, the anaerobic gas production was 1.55 L/d, the COD and NH4+ -N removal efficiency were 93.28% and 90.60% respectively, UAFB effluent including 54.74 mg/L of total VFAs, corresponding NO3- -N accumulating rate was 45.19% and TN removal efficiency was 45.51%. At the same time, it was found that sludge concentration of anoxic tank and aerobic MBR could be maintained at a low level, which is so rich in significance for sludge reduction and delaying membrane fouling.

  1. Dissolved Nutrient Retention Dynamics in River Networks: A Modeling Investigation of Transient Flow and Scale Effects

    Energy Technology Data Exchange (ETDEWEB)

    Ye, Sheng; Covino, Timothy P.; Sivapalan, Murugesu; Basu, Nandita; Li, Hongyi; Wang, Shaowen


    In this paper, we use a dynamic network flow model, coupled with a transient storage zone biogeochemical model, to simulate dissolved nutrient removal processes at the channel network scale. We have explored several scenarios in respect of the combination of rainfall variability, and the biological and geomorphic characteristics of the catchment, to understand the dominant controls on removal and delivery of dissolved nutrients (e.g., nitrate). These model-based theoretical analyses suggested that while nutrient removal efficiency is lower during flood events compared to during baseflow periods, flood events contribute significantly to bulk nutrient removal, whereas bulk removal during baseflow periods is less. This is due to the fact that nutrient supply is larger during flood events; this trend is even stronger in large rivers. However, the efficiency of removal during both periods decreases in larger rivers, however, due to (i) increasing flow velocities and thus decreasing residence time, and (ii) increasing flow depth, and thus decreasing nutrient uptake rates. Besides nutrient removal processes can be divided into two parts: in the main channel and in the hyporheic transient storage zone. When assessing their relative contributions the size of the transient storage zone is a dominant control, followed by uptake rates in the main channel and in the transient storage zone. Increasing size of the transient storage zone with downstream distance affects the relative contributions to nutrient removal of the water column and the transient storage zone, which also impacts the way nutrient removal rates scale with increasing size of rivers. Intra-annual hydrologic variability has a significant impact on removal rates at all scales: the more variable the streamflow is, compared to mean discharge, the less nutrient is removed in the channel network. A scale-independent first order uptake coefficient, ke, estimated from model simulations, is highly dependent on the

  2. Biological mechanisms associated with triazophos (TAP) removal by horizontal subsurface flow constructed wetlands (HSFCW)

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Juan; Feng, Yuqin; Dai, Yanran; Cui, Naxin [State Key Laboratory of Pollution Control and ResourceReuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092 (China); Anderson, Bruce [Department of Civil Engineering, Queen' s University, Kingston K7L3N6 (Canada); Cheng, Shuiping, E-mail: [State Key Laboratory of Pollution Control and ResourceReuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092 (China)


    Triazophos (TAP) is a widely used pesticide that is easily accumulated in the environment due to its relatively high stability: this accumulation from agricultural runoff results in potential hazards to aquatic ecosystems. Constructed wetlands are generally considered to be an effective technology for treating TAP polluted surface water. However, knowledge about the biological mechanisms of TAP removal is still lacking. This study investigates the responses of a wetland plant (Canna indica), substrate enzymes and microbial communities in bench-scale horizontal subsurface-flow constructed wetlands (HSCWs) loaded with different TAP concentrations (0, 0.1, 0.5 and 5 mg·L{sup −1}). The results indicate that TAP stimulated the activities of superoxide dismutase (SOD) and peroxidase (POD) in the roots of C. indica. The highest TAP concentrations significantly inhibited photosynthetic activities, as shown by a reduced effective quantum yield of PS II (Φ{sub PSII}) and lower electron transport rates (ETR). However, interestingly, the lower TAP loadings exhibited some favorable effects on these two variables, suggesting that C. indica is a suitable species for use in wetlands designed for treatment of low TAP concentrations. Urease and alkaline phosphatase (ALP) in the wetland substrate were activated by TAP. Two-way ANOVA demonstrated that urease activity was influenced by both the TAP concentrations and season, while acidphosphatase (ACP) only responded to seasonal variations. Analysis of high throughput sequencing of 16S rRNA revealed seasonal variations in the microbial community structure of the wetland substrate at the phylum and family levels. In addition, urease activity had a greater correlation with the relative abundance of some functional microbial groups, such as the Bacillaceae family, and the ALP and ACP may be influenced by the plant more than substrate microbial communities. - Highlights: • Physiological responses of the wetland plant to triazophos

  3. Biological removal of selenate and ammonium by activated sludge in a sequencing batch reactor. (United States)

    Mal, J; Nancharaiah, Y V; van Hullebusch, E D; Lens, P N L


    Wastewaters contaminated by both selenium and ammonium need to be treated prior to discharge into natural water bodies, but there are no studies on the simultaneous removal of selenium and ammonium. A sequencing batch reactor (SBR) was inoculated with activated sludge and operated for 90days. The highest ammonium removal efficiency achieved was 98%, while the total nitrogen removal was 75%. Nearly a complete chemical oxygen demand removal efficiency was attained after 16days of operation, whereas complete selenate removal was achieved only after 66days. The highest total Se removal efficiency was 97%. Batch experiments showed that the total Se in the aqueous phase decreased by 21% with increasing initial ammonium concentration from 50 to 100mgL(-1). This study showed that SBR can remove both selenate and ammonium via, respectively, bioreduction and partial nitrification-denitrification and thus offer possibilities for treating selenium and ammonium contaminated effluents.

  4. Simultaneous nutrient removal, optimised CO2 mitigation and biofuel feedstock production by Chlorogonium sp. grown in secondary treated non-sterile saline sewage effluent. (United States)

    Lee, Kwan Yin; Ng, Tsz Wai; Li, Guiying; An, Taicheng; Kwan, Ka Ki; Chan, King Ming; Huang, Guocheng; Yip, Ho Yin; Wong, Po Keung


    The phycoremediation process has great potential for effectively addressing environmental pollution. To explore the capabilities of simultaneous algal nutrient removal, CO2 mitigation and biofuel feedstock production from spent water resources, a Chlorogonium sp. isolated from a tilapia pond in Hong Kong was grown in non-sterile saline sewage effluent for a bioremediation study. With high removal efficiencies of NH3-N (88.35±14.39%), NO3(-)-N (85.39±14.96%), TN (93.34±6.47%) and PO4(3-)-P (91.80±17.44%), Chlorogonium sp. achieved a CO2 consumption rate of 58.96 mg L(-1) d(-1), which was optimised by the response surface methodology. Under optimised conditions, the lipid content of the algal biomass reached 24.26±2.67%. Overall, the isolated Chlorogonium sp. showed promising potential in the simultaneous purification of saline sewage effluent in terms of tertiary treatment and CO2 sequestration while delivering feedstock for potential biofuel production in a waste-recycling manner.

  5. Effect of phosphorus load on nutrients removal and N₂O emission during low-oxygen simultaneous nitrification and denitrification process. (United States)

    Jia, Wenlin; Liang, Shuang; Ngo, Huu Hao; Guo, Wenshan; Zhang, Jian; Wang, Rong; Zou, Yina


    Three laboratory scale anaerobic-aerobic (low-oxygen) SBRs (R1, R2 and R3) were conducted at different influent phosphorus concentration to evaluate the impacts of phosphorus load on nutrients removal and nitrous oxide (N₂O) emission during low-oxygen simultaneous nitrification and denitrification (SND) process. The results showed that TP and TN removals were enhanced simultaneously with the increase in phosphorus load. It was mainly caused by the enrichment of polyphosphate accumulating organisms (PAOs) under high phosphorus load and low COD/P ratio (<50), which could use nitrate/nitrite as electron acceptors to take up the phosphorus. N₂O emission was reduced with increasing phosphorus load. N₂O-N emission amount per cycle of R3 was 24.1% lower than that of R1. It was due to the decrease of N₂O yield by heterotrophic denitrification. When the phosphorus load increased from R1 to R3, heterotrophic denitrification (D) ranged from 42.6% to 36.6% of the N₂O yield.

  6. Simultaneous Organics and Nutrients Removal from Domestic Wastewater in a Combined Cylindrical Anoxic/Aerobic Moving Bed Biofilm Reactor

    Directory of Open Access Journals (Sweden)

    Husham T. Ibrahim


    Full Text Available The aim of present study was to design and construct an continuous up-flow pilot scale Moving Bed Biofilm Reactor (MBBR which is consists of combined cylindrical Anoxic/Aerobic MBBR in nested form with anoxic/aerobic volume ratio equal to 0.16 to treated 4 m3 /days of domestic wastewater in Chongqing city at Southwest China. The treatment must be satisfactory to meet with grade B of discharge standard of pollutants for municipal wastewater treatment plant in China (GB/T18918-2002. Kaldnes (K1 media was used as a carrier in both reactors at a media fill ratio equal to 50%. The reactors was operated under the Anoxic/Oxic (An/O process which must meet stringent TN limits without sludge returning into the system and only an internal recycling was performed from aerobic to anoxic reactor. After developing the biofilm on the media, reactor was operated at 3 different Hydraulic Residence Time (HRT ranging from 4.95 to 8.25 h. During operation the internal recycle ratio to eliminate nitrogen compounds were 100% of inflow rate and the average Dissolved Oxygen concentration (DO in aerobic and anoxic MBBRs were 4.49 and 0.16 mg/L, respectively. The obtained results showed that the HRT of 6.2 h was suitable for simultaneous removal of COD, NH4+-N, TN and TP. In this HRT the average removal efficiencies were 93.15, 98.06, 71.67 and 90.88% for COD, NH4+-N, TN and TP, respectively.

  7. Biological Redox Cycling Of Iron In Nontronite And Its Potential Application In Nitrate Removal

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Linduo; Dong, Hailiang; Kukkadapu, Ravi K.; Zeng, Qiang; Edelmann, Richard E.; Pentrak, Martin; Agrawal, Abinash


    Redox cycling of structural Fe in phyllosilicates provides a potential method to remediate nitrate contamination in natural environment. Past research has only studied chemical redox cycles or a single biologically mediated redox cycle of Fe in phyllosilicates. The objective of this research was to study three microbially driven redox cycles of Fe in one phyllosilicate, nontronite (NAu-2). During the reduction phase structural Fe(III) in NAu-2 served as electron acceptor, lactate as electron donor, AQDS as electron shuttle, and dissimilatory Fe(III)-reducing bacteria Shewanella putrefaciens CN32 as mediator in bicarbonate-buffered and PIPES-buffered media. During the oxidation phase, biogenic Fe(II) served an electron donor, nitrate as electron acceptor, and nitrate-dependent Fe(II)-oxidizing bacteria Pseudogulbenkiania sp. strain 2002 as mediator in the same media. For all three cycles, structural Fe in NAu-2 was able to reversibly undergo 3 redox cycles without significant reductive or oxidative dissolution. X-ray diffraction and scanning and transmission electron microscopy revealed that NAu-2 was the dominant residual mineral throughout the 3 redox cycles with some dissolution textures but no significant secondary mineralization. Mössbauer spectroscopy revealed that Fe(II) in bio-reduced samples likely occurred in two distinct environments, at edges and the interior of the NAu-2 structure. Nitrate was completely reduced to nitrogen gas under both buffer conditions and this extent and rate did not change with Fe redox cycles. Mössbauer spectroscopy further revealed that nitrate reduction was coupled to predominant/preferred oxidation of edge Fe(II). These results suggest that structural Fe in phyllosilicates may represent a renewable source to continuously remove nitrate in natural environments.

  8. Biological removal of organic constituents in quench waters from high-Btu coal-gasification pilot plants

    Energy Technology Data Exchange (ETDEWEB)

    Stamoudis, V C; Luthy, R G


    Studies were initiated to assess the efficiency of bench-scale, activated-sludge treatment for removal of organic constituents from coal-gasification process effluents. Samples of pilot-plant, raw-gas quench waters were obtained from the HYGAS process of the Institute of Gas Technology and from the slagging, fixed-bed (SFB) process of the Grand Forks Energy Technology Center. The types of coal employed were Bituminous Illinois No. 6 for the HYGAS and Indian Head lignite for the SFB process. These pilot-plant quench waters, while not strictly representative of commercial condensates, were considered useful to evaluate the efficiency of biological oxidation for the removal of organics. Biological-reactor influent and effluent samples were extracted using a methylene chloride pH-fractionation method into acid, base, and neutral fractions, which were analyzed by capillary-column gas-chromatography/mass-spectrometry. Influent acid fractions of both HYGAS and SFB condensates showed that nearly 99% of extractable and chromatographable organic material comprised phenol and alkylated phenols. Activated-sludge treatment removed these compounds almost completely. Removal efficiency of base-fraction organics was generally good, except for certain alkylated pyridines. Removal of neutral-fraction organics was also good, except for certain alkylated benzenes, certain polycyclic aromatic hydrocarbons, and certain cycloalkanes and cycloalkenes, especially at low influent concentrations.

  9. Determination of biological removal of recalcitrant organic contaminants in coal gasification waste water. (United States)

    Ji, Qinhong; Tabassum, Salma; Yu, Guangxin; Chu, Chunfeng; Zhang, Zhenjia


    Coal gasification waste water treatment needed a sustainable and affordable plan to eliminate the organic contaminants in order to lower the potential environmental and human health risk. In this paper, a laboratory-scale anaerobic-aerobic intermittent system carried out 66 operational cycles together for the treatment of coal gasification waste water and the removal capacity of each organic pollutant. Contaminants included phenols, carboxylic acids, long-chain hydrocarbons, and heterocyclic compounds, wherein the relative content of phenol is up to 57.86%. The long-term removal of 77 organic contaminants was evaluated at different hydraulic retention time (anaerobic24 h + aerobic48 h and anaerobic48 h +aerobic48 h). Contaminant removal ranged from no measurable removal to near-complete removal with effluent concentrations below the detection limit. Contaminant removals followed one of four trends: steady-state removal throughout, increasing removal to steady state (acclimation), decreasing removal, and no removal. Organic degradation and transformation in the reaction were analysed by gas chromatography/mass spectrometry technology.

  10. Rapid start-up of anaerobic ammonium oxidation (anammox) process for nitrogen removal from wastewater


    Ali, Muhammad


    The dissertation is associated with the field of biological wastewater treatment and more precisely focus on nitrogen removal from wastewater. The nutrients removal (mainly N and P) from wastewater is necessary in order to avoid the eutrophication of the surface waters. Nitrogen compounds (NH4+, NO2- and NO3-) removal is commonly performed by means of biological processes due to the lower cost as compared to chemical treatment. The conventional nitrogen removal process consists of two steps, ...

  11. Restoration of Shallow Lakes in Subtropical and Tropical China: Response of Nutrients and Water Clarity to Biomanipulation by Fish Removal and Submerged Plant Transplantation

    Directory of Open Access Journals (Sweden)

    Jinlei Yu


    Full Text Available Fish removal has been used to restore temperate lakes, and positive effects on ecological state and water clarity have frequently been recorded in many lakes. Recently, a supplementary measure, transplantation of submerged macrophytes after fish removal, has been applied to restore warm Chinese shallow lakes in order to compensate for the expected lack of increasing grazing control of phytoplankton after the biomanipulation. These measures have successfully shifted turbid warm lakes to a clear water state, but little is known about the responses to restoration of key physico-chemical variables. We analyzed the seasonal variation in nutrient concentrations in two subtropical and one tropical biomanipulated shallow Chinese lakes subjected to restoration. In all three lakes, a marked decline occurred in the concentrations of lake total nitrogen (TN, total phosphorus (TP, total suspended solids (TSS, and chlorophyll a (Chl a, while the transparency (SD:WD ratio, Secchi depth to water depth ratio increased. A clear water state was established, lasting so far for 7 to 23 months, and TN, TP, Chl a, and TSS levels in the three restored lakes decreased to, on average, 49%, 58%, 41%, and 18% of the level prior to restoration and/or the level in a reference lake, respectively, while the annual mean SD:WD ratio exhibited a 1.5–4 fold increase. In conclusion, lake restoration by transplantation of submerged macrophytes after fish removal had major positive effects on the physico-chemical variables in our study lakes. However, continuous control of omnivorous and herbivorous fish biomass is recommended as the fish typically present in warm, shallow lakes to some extent feed on submerged macrophytes, when available.

  12. Biological potential of extraterrestrial materials. 2. Microbial and plant responses to nutrients in the Murchison carbonaceous meteorite (United States)

    Mautner, M. N.; Conner, A. J.; Killham, K.; Deamer, D. W.


    Meteoritic materials are investigated as potential early planetary nutrients. Aqueous extracts of the Murchison C2 carbonaceous meteorite are utilized as a sole carbon source by microorganisms, as demonstrated by the genetically modified Pseudomonas fluorescence equipped with the lux gene. Nutrient effects are observed also with the soil microorganisms Nocardia asteroides and Arthrobacter pascens that reach populations up to 5 x 10(7) CFU/ml in meteorite extracts, similar to populations in terrestrial soil extracts. Plant tissue cultures of Asparagus officinalis and Solanum tuberosum (potato) exhibit enhanced pigmentation and some enhanced growth when meteorite extracts are added to partial nutrient media, but inhibited growth when added to full nutrient solution. The meteorite extracts lead to large increases in S, Ca, Mg, and Fe plant tissue contents as shown by X-ray fluorescence, while P, K, and Cl contents show mixed effects. In both microbiological and plant tissue experiments, the nutrient and inhibitory effects appear to be best balanced for growth at about 1:20 (extracted solid : H2O) ratios. The results suggest that solutions in cavities in meteorites can provide efficient concentrated biogenic and early nutrient environments, including high phosphate levels, which may be the limiting nutrient. The results also suggest that carbonaceous asteroid resources can sustain soil microbial activity and provide essential macronutrients for future space-based ecosystems.

  13. Modeling Nitrous Oxide Production during Biological Nitrogen Removal via Nitrification and Denitrification: Extensions to the General ASM Models

    DEFF Research Database (Denmark)

    Ni, Bing-Jie; Ruscalleda, Maël; Pellicer i Nàcher, Carles


    Nitrous oxide (N2O) can be formed during biological nitrogen (N) removal processes. In this work, a mathematical model is developed that describes N2O production and consumption during activated sludge nitrification and denitrification. The well-known ASM process models are extended to capture N2O...... dynamics during both nitrification and denitrification in biological N removal. Six additional processes and three additional reactants, all involved in known biochemical reactions, have been added. The validity and applicability of the model is demonstrated by comparing simulations with experimental data...... on N2O production from four different mixed culture nitrification and denitrification reactor study reports. Modeling results confirm that hydroxylamine oxidation by ammonium oxidizers (AOB) occurs 10 times slower when NO2– participates as final electron acceptor compared to the oxic pathway. Among...

  14. Enhanced biological phosphorus removal. Carbon sources, nitrate as electron acceptor, and characterization of the sludge community

    Energy Technology Data Exchange (ETDEWEB)

    Christensson, M.


    Enhanced biological phosphorus removal (EBPR) was studied in laboratory scale experiments as well as in a full scale EBPR process. The studies were focused on carbon source transformations, the use of nitrate as an electron acceptor and characterisation of the microflora. A continuous anaerobic/aerobic laboratory system was operated on synthetic wastewater with acetate as sole carbon source. An efficient EBPR was obtained and mass balances over the anaerobic reactor showed a production of 1.45 g poly-{beta}-hydroxyalcanoic acids (PHA), measured as chemical oxygen demand (COD), per g of acetic acid (as COD) taken up. Furthermore, phosphate was released in the anaerobic reactor in a ratio of 0.33 g phosphorus (P) per g PHA (COD) formed and 0.64 g of glycogen (COD) was consumed per g of acetic acid (COD) taken up. Microscopic investigations revealed a high amount of polyphosphate accumulating organisms (PAO) in the sludge. Isolation and characterisation of bacteria indicated Acinetobacter spp. to be abundant in the sludge, while sequencing of clones obtained in a 16S rDNA clone library showed a large part of the bacteria to be related to the high mole % G+C Gram-positive bacteria and only a minor fraction to be related to the gamma-subclass of proteobacteria to which Acinetobacter belongs. Operation of a similar anaerobic/aerobic laboratory system with ethanol as sole carbon source showed that a high EBPR can be achieved with this compound as carbon source. However, a prolonged detention time in the anaerobic reactor was required. PHA were produced in the anaerobic reactor in an amount of 1.24 g COD per g of soluble DOC taken up, phosphate was released in an amount of 0.4-0.6 g P per g PHA (COD) produced and 0.46 g glycogen (COD) was consumed per g of soluble COD taken up. Studies of the EBPR in the UCT process at the sewage treatment plant in Helsingborg, Sweden, showed the amount of volatile fatty acids (VFA) available to the PAO in the anaerobic stage to be

  15. Modeling nitrous oxide production during biological nitrogen removal via nitrification and denitrification: extensions to the general ASM models. (United States)

    Ni, Bing-Jie; Ruscalleda, Maël; Pellicer-Nàcher, Carles; Smets, Barth F


    Nitrous oxide (N(2)O) can be formed during biological nitrogen (N) removal processes. In this work, a mathematical model is developed that describes N(2)O production and consumption during activated sludge nitrification and denitrification. The well-known ASM process models are extended to capture N(2)O dynamics during both nitrification and denitrification in biological N removal. Six additional processes and three additional reactants, all involved in known biochemical reactions, have been added. The validity and applicability of the model is demonstrated by comparing simulations with experimental data on N(2)O production from four different mixed culture nitrification and denitrification reactor study reports. Modeling results confirm that hydroxylamine oxidation by ammonium oxidizers (AOB) occurs 10 times slower when NO(2)(-) participates as final electron acceptor compared to the oxic pathway. Among the four denitrification steps, the last one (N(2)O reduction to N(2)) seems to be inhibited first when O(2) is present. Overall, N(2)O production can account for 0.1-25% of the consumed N in different nitrification and denitrification systems, which can be well simulated by the proposed model. In conclusion, we provide a modeling structure, which adequately captures N(2)O dynamics in autotrophic nitrification and heterotrophic denitrification driven biological N removal processes and which can form the basis for ongoing refinements.

  16. Some ozone advanced oxidation processes to improve the biological removal of selected pharmaceutical contaminants from urban wastewater. (United States)

    Espejo, Azahara; Aguinaco, Almudena; Amat, Ana M; Beltrán, Fernando J


    Removal of nine pharmaceutical compounds--acetaminophen (AAF), antipyrine (ANT), caffeine (CAF), carbamazepine (CRB), diclofenac (DCF), hydrochlorothiazide (HCT), ketorolac (KET), metoprolol (MET) and sulfamethoxazole (SMX)-spiked in a primary sedimentation effluent of a municipal wastewater has been studied with sequential aerobic biological and ozone advanced oxidation systems. Combinations of ozone, UVA black light and Fe(III) or Fe3O4 constituted the chemical systems. During the biological treatment (hydraulic residence time, HRT = 24 h), only AAF and CAF were completely eliminated, MET, SMX and HCT reached partial removal rates and the rest of compounds were completely refractory. With any ozone advanced oxidation process applied, the remaining pharmaceuticals disappear in less than 10 min. Fe3O4 or Fe(III) photocatalytic ozonation leads to 35% mineralization compared to 13% reached during ozonation alone after about 30-min reaction. Also, biodegradability of the treated wastewater increased 50% in the biological process plus another 150% after the ozonation processes. Both untreated and treated wastewater was non-toxic for Daphnia magna (D. magna) except when Fe(III) was used in photocatalytic ozonation. In this case, toxicity was likely due to the ferryoxalate formed in the process. Kinetic information on ozone processes reveals that pharmaceuticals at concentrations they have in urban wastewater are mainly removed through free radical oxidation.

  17. A review: Potential and challenges of biologically activated carbon to remove natural organic matter in drinking water purification process. (United States)

    Korotta-Gamage, Shashika Madushi; Sathasivan, Arumugam


    The use of biologically activated carbon (BAC) in drinking water purification is reviewed. In the past BAC is seen mostly as a polishing treatment. However, BAC has the potential to provide solution to recent challenges faced by water utilities arising from change in natural organic matter (NOM) composition in drinking water sources - increased NOM concentration with a larger fraction of hydrophilic compounds and ever increasing trace level organic pollutants. Hydrophilic NOM is not removed by traditional coagulation process and causes bacterial regrowth and increases disinfection by-products (DBPs) formation during disinfection. BAC can offer many advantages by removing hydrophilic fraction and many toxic and endocrine compounds which are not otherwise removed. BAC can also aid the other downstream processes if used as a pre-treatment. Major drawback of BAC was longer empty bed contact time (EBCT) required for an effective NOM removal. This critical review analyses the strategies that have been adopted to enhance the biological activity of the carbon by operational means and summarises the surface modification methods. To maximize the benefit of the BAC, a rethink of current treatment plant configuration is proposed. If the process can be expedited and adopted appropriately, BAC can solve many of the current problems.

  18. Wastewater nutrient removal in a mixed microalgae-bacteria culture: effect of light and temperature on the microalgae-bacteria competition. (United States)

    González-Camejo, J; Barat, R; Pachés, M; Murgui, M; Seco, A; Ferrer, J


    The aim of this study was to evaluate the effect of light intensity and temperature on nutrient removal and biomass productivity in a microalgae-bacteria culture and their effects on the microalgae-bacteria competition. Three experiments were carried out at constant temperature and various light intensities: 40, 85 and 125 µE m(-2) s(-1). Other two experiments were carried out at variable temperatures: 23 ± 2°C and 28 ± 2°C at light intensity of 85 and 125 µE m(-2) s(-1), respectively. The photobioreactor was fed by the effluent from an anaerobic membrane bioreactor. High nitrogen and phosphorus removal efficiencies (about 99%) were achieved under the following operating conditions: 85-125 µE m(-2) s(-1) and 22 ± 1°C. In the microalgae-bacteria culture studied, increasing light intensity favoured microalgae growth and limited the nitrification process. However, a non-graduated temperature increase (up to 32°C) under the light intensities studied caused the proliferation of nitrifying bacteria and the nitrite and nitrate accumulation. Hence, light intensity and temperature are key parameters in the control of the microalgae-bacteria competition. Biomass productivity significantly increased with light intensity, reaching 50.5 ± 9.6, 80.3 ± 6.5 and 94.3 ± 7.9 mgVSS L(-1) d(-1) for a light intensity of 40, 85 and 125 µE m(-2) s(-1), respectively.

  19. A DO- and pH-Based Early Warning System of Nitrification Inhibition for Biological Nitrogen Removal Processes

    Directory of Open Access Journals (Sweden)

    Hyunook Kim


    Full Text Available In Korea, more than 80% of municipal wastewater treatment plants (WWTPs with capacities of 500 m3·d−1 or more are capable of removing nitrogen from wastewater through biological nitrification and denitrification processes. Normally, these biological processes show excellent performance, but if a toxic chemical is present in the influent to a WWTP, the biological processes (especially, the nitrification process may be affected and fail to function normally; nitrifying bacteria are known very vulnerable to toxic substances. Then, the toxic compound as well as the nitrogen in wastewater may be discharged into a receiving water body without any proper treatment. Moreover, it may take significant time for the process to return back its normal state. In this study, a DO- and pH-based strategy to identify potential nitrification inhibition was developed to detect early the inflow of toxic compounds to a biological nitrogen removal process. This strategy utilizes significant changes observed in the oxygen uptake rate and the pH profiles of the mixed liquor when the activity of nitrifying bacteria is inhibited. Using the strategy, the toxicity from test wastewater with 2.5 mg·L−1 Hg2+, 0.5 mg·L−1 allythiourea, or 0.25 mg·L−1 chloroform could be successfully detected.

  20. Biological removal of phenol from saline wastewater using a moving bed biofilm reactor containing acclimated mixed consortia. (United States)

    Nakhli, Seyyed Ali Akbar; Ahmadizadeh, Kimia; Fereshtehnejad, Mahmood; Rostami, Mohammad Hossein; Safari, Mojtaba; Borghei, Seyyed Mehdi


    In this study, the performance of an aerobic moving bed biofilm reactor (MBBR) was assessed for the removal of phenol as the sole substrate from saline wastewater. The effect of several parameters namely inlet phenol concentration (200-1200 mg/L), hydraulic retention time (8-24 h), inlet salt content (10-70 g/L), phenol shock loading, hydraulic shock loading and salt shock loading on the performance of the 10 L MBBR inoculated with a mixed culture of active biomass gradually acclimated to phenol and salt were evaluated in terms of phenol and chemical oxygen demand (COD) removal efficiencies. The results indicated that phenol and COD removal efficiencies are affected by HRT, phenol and salt concentration in the bioreactor saline feed. The MBBR could remove up to 99% of phenol and COD from the feed saline wastewater at inlet phenol concentrations up to 800 mg/L, HRT of 18 h and inlet salt contents up to 40 g/L. The reactor could also resist strong shock loads. Furthermore, measuring biological quantitative parameters indicated that the biofilm plays a main role in phenol removal. Overall, the results of this investigation revealed that the developed MBBR system with high concentration of the active mixed biomass can play a prominent role in order to treat saline wastewaters containing phenol in industrial applications as a very efficient and flexible technology.

  1. Biological removal of air loaded with a hydrogen sulfide and ammonia mixture

    Institute of Scientific and Technical Information of China (English)

    CHEN Ying-xu; YIN Jun; FANG Shi


    The nuisance impact of air pollutant emissions from wastewater pumping stations is a major issue of concern to China. Hydrogen sulfide and ammonia are commonly the primary odor and are important targets for removal. An alternative control technology, biofiltration, was studied. The aim of this study is to investigate the potential of unit systems packed with compost in terms of ammonia and hydrogen sulfide emissions treatment, and to establish optimal operating conditions for a full-scale conceptual design. The laboratory scale biofilter packed with compost was continuously supplied with hydrogen sulfide and ammonia gas mixtures. A volumetric load of less than 150 gH2S/(m3· d) and 230 gNH3/(m3· d) was applied for about fifteen weeks. Hydrogen sulfide and ammonia elimination occurred in the biofilter simultaneously. The removal efficiency, removal capacity and removal kinetics in the biofilter were studied. The hydrogen sulfide removal efficiency reached was very high above 99%, and ammonia removal efficiency was about 80%. Hydrogen sulfide was oxidized into sulphate. The ammonia oxidation products were nitrite and nitrate. Ammonia in the biofilter was mainly removed by adsorption onto the carrier material and by absorption into the water fraction of the carrier material. High percentages of hydrogen sulfide or ammonia were oxidized in the first section of the column. Through kinetics analysis, the presence of amrronia did not hinder the hydrogen sulfide removal. According to the relationship between pressure drop and gas velocity for the biofilter and Reynolds number, non-Darcy flow can be assumed to represent the flow in the medium.

  2. Removal of pharmaceuticals in biologically treated wastewater by chlorine dioxide or peracetic acid. (United States)

    Hey, G; Ledin, A; Jansen, J la Cour; Andersen, H R


    Removal of six active pharmaceutical ingredients in wastewater was investigated using chlorine dioxide (ClO2) or peracetic acid (PAA) as chemical oxidants. Four non-steroidal anti-inflammatory drugs (ibuprofen, naproxen, diclofenac and mefenamic acid) and two lipid-regulating agents (gemfibrozil and clofibric acid, a metabolite of clofibrate) were used as target substances at 40 microg/L initial concentration. Three different wastewaters types originating from two wastewater treatment plants (WWTPs) were used. One wastewater was collected after extended nitrogen removal in activated sludge, one after treatment with high-loaded activated sludge without nitrification, and one from the final effluent from the same plant where nitrogen removal was made in trickling filters for nitrification and moving-bed biofilm reactors for denitrification following the high-loaded plant. Of the six investigated compounds, only clofibric acid and ibuprofen were not removed when treated with ClO2 up to 20 mg/L. With increasing PAA dose up to 50 mg/L, significant removal of most of the pharmaceuticals was observed except for the wastewater with the highest chemical oxygen demand (COD). This indicates that chemical oxidation with ClO2 could be used for tertiary treatment at WWTPs for active pharmaceutical ingredients, whereas PAA was not sufficiently efficient.

  3. Removal of pharmaceuticals in biologically treated wastewater by chlorine dioxide or peracetic acid

    DEFF Research Database (Denmark)

    Hey, G.; Ledin, Anna; La Cour Jansen, Jes


    Removal of six active pharmaceutical ingredients in wastewater was investigated using chlorine dioxide (ClO2) and peracetic acid (PAA) as chemical oxidants. Four non-steroidal anti -inflammatory drugs (ibuprofen, naproxen, diclofenac, and mefenamic acid) and two l ipid regulating agents (gemfibrozi...... compounds, only clofibric acid and ibuprofen were not removed when treated wi th ClO2 up to 20 mg/L. Wi th increasing PAA dose up to 50 mg/L, signi ficant removal of most of the pharmaceutical s was observed except for the wastewater wi th the highest COD. Thi s indicates that chemical oxidation wi th ClO2...... could be used for tertiary treatment at WWTPs for active pharmaceutical ingredients whi le PAA was not sufficiently efficient....

  4. Efficacy and reliability of upgraded industrial treatment plant at Porto Marghera, near Venice, Italy, in removing nutrients and dangerous micropollutants from petrochemical wastewaters. (United States)

    Verlicchi, Paola; Cattaneo, Serena; Marciano, Ferdinando; Masotti, Luigi; Vecchiato, Giuseppe; Zaffaroni, Carlo


    Chemical and petrochemical wastewaters contain a host of contaminants that require different treatment strategies. Regulation of macropollutants and micropollutants in the final discharge from industrial wastewater treatment plants (WWTPs) have become increasingly stringent in recent decades, requiring many WWTPs to be upgraded. This article presents an analysis of a WWTP treating petrochemicals in Porto Marghera, Italy, that recently was upgraded following legislative changes. Because of strict legal limits for macropollutants and micropollutants and a lack of space necessary for a full-scale WWTP overhaul, the existing activated sludge tank was converted into a membrane biological reactor. The paper presents experimental data collected during a five-month investigation showing the removal rates achieved by the upgraded plant for macropollutants (particularly nitrogen compounds) and micropollutants (heavy metals and organic and inorganic toxic compounds).

  5. Effect of carbon sources on biological nitrogen and phosphorus removal in the municipal wastewater treatment system%碳源对污水处理系统脱氮除磷的影响

    Institute of Scientific and Technical Information of China (English)

    林雨倩; 赵军


    The performance of biological nutrient removal (BNR) processes is directly connected to the availability of carbon sources. This study introduces the metabolism mechanisms of carbon sources in each step of biological nitrogen and phosphorus removal processes, and the types and concentrations of carbon sources on the nitrogen and phosphorus removal are also discussed. It was revealed that the effective use of organic substrate including external and internal carbon sources could enhance the purifying performance of the system.%在污水强化生物脱氮除磷系统中,碳源种类及浓度对于处理系统去除效果的高效运行起到重要的作用。通过介绍生物脱氮及除磷各步骤碳源需求的机理,探讨碳源类型及碳源浓度对系统脱氮除磷效果的影响,同时对提高污水碳源浓度常用的手段即增加外碳源及内碳源方法进行分析。

  6. Control of a Biological Nitrogen Removal Process in an Intensified Single Reactor Configuration

    DEFF Research Database (Denmark)

    Vangsgaard, Anna Katrine; Mauricio Iglesias, Miguel; Gernaey, Krist;


    The nitrogen removing granular sludge process is a novel and intensified process. However, its stable operation and control remains a challenging problem. In this contribution, a new process oriented approach is used to develop, evaluate and benchmark control strategies to ensure stable operation...

  7. Simultaneous biological removal of sulfide and nitrate by autotrophic denitrification in an activated sludge system

    NARCIS (Netherlands)

    Manconi, I.; Carucci, A.; Lens, P.N.L.; Rossetti, S.


    The feasibility of an autotrophic denitrification process in an activated sludge reactor, using sulphide as the electron donor, was tested for simultaneous denitrification and sulphide removal. The reactor was operated at nitrate (N) to sulphide (S) ratios between 0.5 and 0.9 to evaluate their effec

  8. Effect of Return Sludge Pre-concentration on Biological Phosphorus Removal in a Novel Oxidation Ditch

    Institute of Scientific and Technical Information of China (English)

    刘巍; 扬殿海; 徐立; 贾川; 卢文建; BOSIRE Omosa Isaiah; 沈昌明


    A pilot-scale,pre-anoxic-anaerobic oxidation ditch was used in this study to treat municipal wastewater with limited carbon source.A novel return activated sludge(RAS) pre-concentration tank was adopted for improv-ing the phosphorus removal efficiency and the effects of RAS pre-concentration ratio were studied.Under the opti-mal operational condition,the suspended total phosphorus(STP) and the total phosphorus(TP) removal efficiencies were around 58.9% and 63.9% respectively and the effluent-P was lower than 0.8 mg·L-1.The reason is that with the optimal RAS pre-concentration ratio,nitrate is completely removed with endogenous carbon source and the secondary phosphorus release is strictly restrained in the pre-anoxic tank.Therefore,the anaerobic phosphorus release and the carbon source uptake by phosphorus accumulation organisms(PAOs) in the sludge,which are ex-tremely important to the phosphorus removal process,can be fully satisfied.Furthermore,the oxidation-reduction potential is proved to be suitable for controlling the RAS pre-concentration ratio due to influent fluctuation and varied conditions.The novel modified system is also beneficial for PAO accumulation.

  9. Combined ion exchange/biological denitrification for nitrate removal from ground water.

    NARCIS (Netherlands)

    Hoek, van der J.P.


    This thesis deals with the development of a new process for nitrate removal from ground water. High nitrate concentrations in ground water are a result of fertilization in agriculture. According to a directive of the European Community the maximum admissible concentration of nitrate in drinking wate

  10. Control structure design for resource recovery using the enhanced biological phosphorus removal and recovery (EBP2R) activated sludge process

    DEFF Research Database (Denmark)

    Valverde Perez, Borja; Fuentes-Martínez, José Manuel; Flores Alsina, Xavier


    structurefor the novel enhanced biological phosphorus removal and recovery (EBP2R) process, which is currentlyunder development. The aim of the EBP2R is to maximize phosphorus recovery through optimal greenmicro-algal cultivation, which is achieved by controlling the nitrogen to phosphorus ratio (N-to-P ratio......Nowadays, wastewater is considered as a set of resources to be recovered rather than a mixture of pollutantsthat should be removed. Many resource recovery schemes have been proposed, involving the useof novel technologies whose controllability is poorly studied. In this paper we present a control...... in the effluent (16.9 ± 0.07) and can recover about 72% of the influent phosphorus. The phosphorus recovered by the CFS is limited by the influent nitrogen (65% of the influent phosphorus load). Using the CFS configuration the effluent N-to-P ratio cannot be effectively controlled (16.45 ± 2.48). Therefore...

  11. Biological Removal of Ammonia from Contaminated Air Streams Using Biofiltration System

    Directory of Open Access Journals (Sweden)

    MR Shahmansouri, H Taghipour, B Bina, H Movahdian


    Full Text Available Ammonia is a colorless, toxic, reactive and corrosive gas with a sharp odor. It is irritating to the skin, eyes, nose, throat, and lungs. Ammonia gas occurs in the environment naturally and is emitted by many industries and, therefore, its control is essential. Biofiltration is a new emerging technology that is being used as a control procedure. This study evaluates the use of a mixture of compost, sludge, and pieces of PVC as biofilter media to remove ammonia gas. The study investigates the effects of parameters such as inlet concentration, accumulation time, and depth of filter media to evaluate the removal efficiency. A laboratory scale biofilter column was built and operated to investigate the removal of ammonia from a waste gas stream. The findings indicate that for inlet concentrations of 236 ppm, and ammonia loading of less than 9.86 g-NH3/m3.h at empty bed residence time of 1 min, an ammonia removal efficiency of more than 99.9% was obtained. The acclimation period of the bacteria was 10 days. The average pressure drop during measurement was 4.44 mm H2O. The study also revealed that for concentration levels of 99, 211, and 236 ppmv, biofilter media depths of 40, 80, and 120 cm will be required, respectively. The results obtained in this study indicate that the biofiltration system composed of compost in the mixture of sludge and smashed polyvinyl chloride as biofilter media is an efficient method for the removal of ammonia from waste gas streams. It is also found that the optimum depth of biofilter media depends on the inlet concentration of ammonia.

  12. Atmospheric deposition impacts on nutrients and biological budgets of the Mediterranean Sea, results from the high resolution coupled model NEMOMED12/PISCES (United States)

    Richon, Camille; Dutay, Jean-Claude; Dulac, François; Desboeufs, Karine; Nabat, Pierre; Guieu, Cécile; Aumont, Olivier; Palmieri, Julien


    Atmospheric deposition is at present not included in regional oceanic biogeochemical models of the Mediterranean Sea, whereas, along with river inputs, it represents a significant source of nutrients at the basin scale, especially through intense desert dust events. Moreover, observations (e.g. DUNE campaign, Guieu et al. 2010) show that these events significantly modify the biogeochemistry of the oligotrophic Mediterranean Sea. We use a high resolution (1/12°) version of the 3D coupled model NEMOMED12/PISCES to investigate the effects of high resolution atmospheric dust deposition forcings on the biogeochemistry of the Mediterranean basin. The biogeochemical model PISCES represents the evolution of 24 prognostic tracers including five nutrients (nitrate, ammonium, phosphate, silicate and iron) and two phytoplankton and zooplanktons groups (Palmiéri, 2014). From decadal simulations (1982-2012) we evaluate the influence of natural dust and anthropogenic nitrogen deposition on the budget of nutrients in the basin and its impact on the biogeochemistry (primary production, plankton distributions...). Our results show that natural dust deposition accounts for 15% of global PO4 budget and that it influences primarily the southern part of the basin. Anthropogenic nitrogen accounts for 50% of bioavailable N supply for the northern part. Deposition events significantly affect biological production; primary productivity enhancement can be as high as 30% in the areas of high deposition, especially during the stratified period. Further developments of the model will include 0D and 1D modeling of bacteria in the frame of the PEACETIME project.

  13. Pharmacia and biological functionalities of nutrient broth dispersed multi-walled carbon nanotubes:A novel drug delivery system

    Institute of Scientific and Technical Information of China (English)


    A new drug delivery system was developed using the interaction of nutrient broth treated multi-walled carbon nanotubes(NBT-MWCNTs) and cefotaxime sodium(CTX) as a model.Investigated factors of the drug delivery system include dispersion effect,biocompatibility of NBT-MWCNTs,pharmacodynamic effect and delivery efficiency in vitro.It was found that MWCNTs can be well dispersed in the nutrient broth and stable at least for one week at 4 °C.The formed NBT-MWCNTs suspension scarcely exhibits toxicity to E.coli at concentrations lower than 10.24 μg/mL,but displays enhanced pharmacodynamic effect of CTX via its bridge effect and targeted transport.Compared with general acid treated MWCNTs(AT-MWCNTs),our present NBT-MWCNTs show good biocompatibility,enhanced pharmacodynamic effect,and high delivery efficiency.

  14. Removal of polar UV stabilizers in biological wastewater treatments and ecotoxicological implications. (United States)

    Molins-Delgado, Daniel; Díaz-Cruz, M Silvia; Barceló, Damià


    The present study describes the development, validation and application of a fully automated analytical method based on on-line solid-phase extraction-liquid chromatography-tandem mass spectrometry (on line SPE-HPLC-MS/MS) to assess the removal efficiency in water works and the ecotoxicological implications derived of the two most used benzotriazole-class UV stabilizers (BZTs), namely 1H-benzotriazole (BZT) and 5-methyl-1H-benzotriazole (MeBZT). Influent and effluent wastewater samples from 20 wastewater treatment plants (WWTPs) were analyzed. Removal rates (RE%) and half-lives (t1/2) for each BZTs were calculated and correlated to the hydraulic retention time (HRT) of each plant. Both BZTs were detected in all influent and effluent samples (concentrations in the range 26.7 ng L(-1)-42.9 μg L(-1)), with the highest concentrations corresponding to MeBZT. Results indicated that both compounds were recalcitrant (RE% in the range 11.8-94.7%) and that no clear influence of HRT on removals could be drawn. Finally, the potential environmental risk posed by the levels of BZTs detected was evaluated calculating the hazard quotients (HQs) MeBZT was the only BZTs posing a risk to Vibrio fischeri, Daphnia galeata and Pimephales promelas.

  15. Biological removal of gaseous ammonia in biofilters: space travel and earth-based applications (United States)

    Joshi, J. A.; Hogan, J. A.; Cowan, R. M.; Strom, P. F.; Finstein, M. S.; Janes, H. W. (Principal Investigator)


    Gaseous NH3 removal was studied in laboratory-scale biofilters (14-L reactor volume) containing perlite inoculated with a nitrifying enrichment culture. These biofilters received 6 L/min of airflow with inlet NH3 concentrations of 20 or 50 ppm, and removed more than 99.99% of the NH3 for the period of operation (101, 102 days). Comparison between an active reactor and an autoclaved control indicated that NH3 removal resulted from nitrification directly, as well as from enhanced absorption resulting from acidity produced by nitrification. Spatial distribution studies (20 ppm only) after 8 days of operation showed that nearly 95% of the NH3 could be accounted for in the lower 25% of the biofilter matrix, proximate to the port of entry. Periodic analysis of the biofilter material (20 and 50 ppm) showed accumulation of the nitrification product NO3- early in the operation, but later both NO2- and NO3- accumulated. Additionally, the N-mass balance accountability dropped from near 100% early in the experiments to approximately 95 and 75% for the 20- and 50-ppm biofilters, respectively. A partial contributing factor to this drop in mass balance accountability was the production of NO and N2O, which were detected in the biofilter exhaust.

  16. Biological Behavior of Anammox Process for Municipal Wastewater Treatment: Effect of Ammonia Removal and Other Parameters

    Directory of Open Access Journals (Sweden)

    *R. Nabizadeh


    Full Text Available Historically, nitrogen compound due to major environmental and public health problems have been considered. Anaerobic ammonium oxidation processes were proposed by many advantages such as; novelty, promising method and cost-effective. In this work, we used of anommax process for a wastewater with high C:N ratios and the main parameter likes pH; temperature, NO2/NH4 ratio and behavior of COD, ammonium and nitrite during operation time of 55 days were evaluated. High efficiency in nitrite and ammonium removal is observed at pH values between 7.5 to 8 and operation times between 9 to 23 days. Furthermorethe variation of the nitrite/ammonium ratio done dependence to pH, and a higher ratio was associated with higher pH values. And lower values of NO2/NH4 ratio have occurred with decrease of pH at third phase of anommax process. The average elimination efficiency of COD was occurred about 89.22%, but the removal efficiency of COD in anommax reactor was obtained about 49.5%. Furthermorethe removal efficiency of ammonium and nitrite were provided about 50% for each.

  17. Biological removal of triphenylmethane dyes from aqueous solution by Lemna minor. (United States)

    Török, Anamaria; Buta, Erzsébet; Indolean, Cerasella; Tonk, Szende; Silaghi-Dumitrescu, Luminita; Majdik, Cornelia


    The aim of this study is to investigate and develop a phytoremediation method for the removal of two triphenylmethane dyes (crystal violet and malachite green) using an aquatic plant, Lemna minor. The effects of operational parameters such as aquatic plant quantity, initial dye concentration, initial pH of the solutions and temperature of the medium were studied in order to determine the optimum phytoremediation conditions. The plant's photosynthetic pigments were determined quantitatively in order to detect the plant's response to abiotic stress. During the phytoremediation experiments the parallel sub-processes (phytosorption, phytoextraction, phytodegradation) were observed and analysed. The mechanisms of phytoremediation were studied using Fourier transformation infrared spectroscopy, ultraviolet-visible spectroscopy, thin layer chromatography and Energy-dispersive X-ray spectroscopy. Results show that the plant tolerated high concentrations (300 mg/L) of dyes, and was able to remove from the environment and accumulate in its cells the dyes up to a significant percentage (crystal violet was removed by about 80% and malachite green by 90%).

  18. Biological sulfate removal from acrylic fiber manufacturing wastewater using a two-stage UASB reactor

    Institute of Scientific and Technical Information of China (English)

    Jin Li; Jun Wang; Zhaokun Luan; Zhongguang Ji; Lian Yu


    A two-stage UASB reactor was employed to remove sulfate from acrylic fiber manufacturing wastewater.Mesophilic operation (35±0.5℃) was performed with hydraulic retention time (HRT) varied between 28 and 40 hr.Mixed liquor suspended solids (MLSS)in the reactor was maintained about 8000 mg/L.The results indicated that sulfate removal was enhanced with increasing the ratio of COD/SO42-.At low COD/SO42-,the growth of the sulfate-reducing bacteria (SRB) was carbon-limited.The optimal sulfate removal efficiencies were 75% when the HRT was no less than 38 hr.Sulfidogenesis mainly happened in the sulfate-reducing stage,while methanogenesis in the methane-producing stage.Microbes in sulfate-reducing stage performed granulation better than that in methaneproducing stage.Higher extracellular polymeric substances (EPS) content in sulfate-reducing stage helped to adhere and connect the flocculent sludge particles together.SRB accounted for about 31% both in sulfate-reducing stage and methane-producing stage at COD/SO42- ratio of 0.5,while it dropped dramatically from 34% in sulfate-reducing stage to 10% in methane-producing stage corresponding to the COD/SO42- ratio of 4.7.SRB and MPA were predominant in sulfate-reducing stage and methane-producing stage respectively.

  19. Evaluation of ion exchange resins for the removal of dissolved organic matter from biologically treated paper mill effluent. (United States)

    Bassandeh, Mojgan; Antony, Alice; Le-Clech, Pierre; Richardson, Desmond; Leslie, Greg


    In this study, the efficiency of six ion exchange resins to reduce the dissolved organic matter (DOM) from a biologically treated newsprint mill effluent was evaluated and the dominant removal mechanism of residual organics was established using advanced organic characterisations techniques. Among the resins screened, TAN1 possessed favourable Freundlich parameters, high resin capacity and solute affinity, closely followed by Marathon MSA and Marathon WBA. The removal efficiency of colour and lignin residuals was generally good for the anion exchange resins, greater than 50% and 75% respectively. In terms of the DOM fractions removal measured through liquid chromatography-organic carbon and nitrogen detector (LC-OCND), the resins mainly targeted the removal of humic and fulvic acids of molecular weight ranging between 500 and 1000 g mol(-1), the portion expected to contribute the most to the aromaticity of the effluent. For the anion exchange resins, physical adsorption operated along with ion exchange mechanism assisting to remove neutral and transphilic acid fractions of DOM. The column studies confirmed TAN1 being the best of those screened, exhibited the longest mass transfer zone and maximum treatable volume of effluent. The treatable effluent volume with 50% reduction in dissolved organic carbon (DOC) was 4.8 L for TAN1 followed by Marathon MSA - 3.6L, Marathon 11 - 2.0 L, 21K-XLT - 1.5 L and Marathon WBA - 1.2 L. The cation exchange resin G26 was not effective in DOM removal as the maximum DOC removal obtained was only 27%. The resin capacity could not be completely restored for any of the resins; however, a maximum restoration up to 74% and 93% was achieved for TAN1 and Marathon WBA resins. While this feasibility study indicates the potential option of using ion exchange resins for the reclamation of paper mill effluent, the need for improving the regeneration protocols to restore the resin efficiency is also identified. Similarly, care should be taken

  20. Artificial intelligence models for predicting the performance of biological wastewater treatment plant in the removal of Kjeldahl Nitrogen from wastewater (United States)

    Manu, D. S.; Thalla, Arun Kumar


    The current work demonstrates the support vector machine (SVM) and adaptive neuro-fuzzy inference system (ANFIS) modeling to assess the removal efficiency of Kjeldahl Nitrogen of a full-scale aerobic biological wastewater treatment plant. The influent variables such as pH, chemical oxygen demand, total solids (TS), free ammonia, ammonia nitrogen and Kjeldahl Nitrogen are used as input variables during modeling. Model development focused on postulating an adaptive, functional, real-time and alternative approach for modeling the removal efficiency of Kjeldahl Nitrogen. The input variables used for modeling were daily time series data recorded at wastewater treatment plant (WWTP) located in Mangalore during the period June 2014-September 2014. The performance of ANFIS model developed using Gbell and trapezoidal membership functions (MFs) and SVM are assessed using different statistical indices like root mean square error, correlation coefficients (CC) and Nash Sutcliff error (NSE). The errors related to the prediction of effluent Kjeldahl Nitrogen concentration by the SVM modeling appeared to be reasonable when compared to that of ANFIS models with Gbell and trapezoidal MF. From the performance evaluation of the developed SVM model, it is observed that the approach is capable to define the inter-relationship between various wastewater quality variables and thus SVM can be potentially applied for evaluating the efficiency of aerobic biological processes in WWTP.

  1. Biological responses of the coral Montastraea annularis to the removal of filamentous turf algae.

    Directory of Open Access Journals (Sweden)

    Neidy P Cetz-Navarro

    Full Text Available Coral reef degradation increases coral interactions with filamentous turf algae (FTA and macroalgae, which may result in chronic stress for the corals. We evaluated the effects of short (2.5 month and long (10 month periods of FTA removal on tissue thickness (TT, zooxanthellae density (ZD, mitotic index (MI, and concentration of chlorophyll a (Chl a in Montastraea annularis at the beginning and end of gametogenesis. Ramets (individual lobes within a colony consistently surrounded by FTA and ramets surrounded by crustose coralline algae (CCA were used as controls. FTA removal reduced coral stress, indicated by increased TT and ZD and lower MI. The measured effects were similar in magnitude for the short and long periods of algal removal. Ramets were more stressed at the end of gametogenesis compared with the beginning, with lower ZD and Chl a cm(-2, and higher MI. However, it was not possible to distinguish the stress caused by the presence of FTA from that caused by seasonal changes in seawater temperature. Ramets surrounded by CCA showed less stress in comparison with ramets surrounded by FTA: with higher TT, Chl a cm(-2 and ZD, and lower MI values. Coral responses indicated that ramets with FTA suffered the most deleterious effects and contrasted with those measured in ramets surrounded by CCA. According to published studies and our observations, there could be at least six mechanisms associated to FTA in the stress caused to M. annularis by FTA. Owing to the high cover of FTA (in contrast to macroalgae and CCA in the Caribbean, the chronic stress, the overgrowth and mortality that this functional algal group can cause on M. annularis species complex, a further decline of this important reef-building coral in the Caribbean is expected.

  2. A consilience model to describe N2O production during biological N removal

    DEFF Research Database (Denmark)

    Domingo Felez, Carlos; Smets, Barth F.


    Nitrous oxide (N2O), a potent greenhouse gas, is produced during biological nitrogen conversion in wastewater treatment operations. Complex mechanisms underlie N2O production by autotrophic and heterotrophic organisms, which continue to be unravelled. Mathematical models that describe nitric oxide...... (NO) and N2O dynamics have been proposed. Here, a first comprehensive model that considers all relevant NO and N2O production and consumption mechanisms is proposed. The model describes autotrophic NO production by ammonia oxidizing bacteria associated with ammonia oxidation and with nitrite reduction......, followed by NO reduction to N2O. It also considers NO and N2O as intermediates in heterotrophic denitrification in a 4-step model. Three biological NO and N2O production pathways are accounted for, improving the capabilities of existing models while not increasing their complexity. Abiotic contributions...

  3. Effect of Ferric Chloride on the Properties of Biological Sludge in Co-precipitation Phosphorus Removal Process

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhibin; LI Yi; WEI Leilei; L(U) Yufeng; WANG Meng; GAO Baoyu


    This paper studied the effect of ferric chloride on waste sludge digestion,dewatering and sedimentation under the optimized doses in co-precipitation phosphorus removal process.The experimental results showed that the concentration of mixed liquid suspended solid (MLSS) was 2436 mg·L-1 and 2385 mg·L-1 in co-precipitation phosphorus removal process (CPR) and biological phosphorous removal process (BPR),respectively.The sludge reduction ratio for each process was 22.6% and 24.6% in aerobic digestion,and 27.6% and 29.9% in anaerobic digestion,respectively.Due to the addition of chemical to the end of aeration tank,the sludge content of CPR was slightly higher than that of BPR,but the sludge reduction rate for both processes had no distinct difference.The sludge volume index (SVI) and sludge specific resistance of BPR were 126 ml·g-1 and 11.7×1012 m·kg-1,respectively,while those of CPR were only 98 ml·g-1 and 7.1×1012 m·kg-1,indicating that CPR chemical could improve sludge settling and dewatering.

  4. Enhanced nitrogen removal in a wastewater treatment process characterized by carbon source manipulation with biological adsorption and sludge hydrolysis. (United States)

    Liu, Hongbo; Zhao, Fang; Mao, Boyang; Wen, Xianghua


    An innovative adsorption/nitrification/denitrification/sludge-hydrolysis wastewater treatment process (ENRS) characterized by carbon source manipulation with a biological adsorption unit and a sludge hydrolysis unit was developed to enhance nitrogen removal and reduce sludge production for municipal wastewater treatment. The system presented good performance in pollutants removal, yielding the effluent with average COD, NH(4)(+)-N, TN and TP of 48.5, 0.6, 13.2 and 1.0 mg/L, respectively. Sixty percent of the total carbon source in the influent was concentrated and separated by the quick adsorption of activated sludge, providing the possibilities of reusing waste carbon source in the denitrification tank and accumulating nitrobacteria in the nitrification tank. Low temperature of 6-15 °C and high hydraulic loading rate of 3.0-15.0 m(3)/d did not affect NH(4)(+)-N removal performance, yielding the NH(4)(+)-N of lower 1.0 mg/L in the effluent. Furthermore, 50% of the residual sludge in the ENRS system could be transformed into soluble COD (SCOD) by alkaline thermal hydrolysis with temperature of 60 °C and pH of 11, and the hydrolyzed carbon could completely substitute methanol as a good quality carbon to support high efficient denitrification.

  5. Ozone-biological activated carbon integrated treatment for removal of precursors of halogenated nitrogenous disinfection by-products. (United States)

    Chu, Wenhai; Gao, Naiyun; Yin, Daqiang; Deng, Yang; Templeton, Michael R


    Pilot-scale tests were performed to reduce the formation of several nitrogenous and carbonaceous disinfection by-products (DBPs) with an integrated ozone and biological activated carbon (O(3)-BAC) treatment process following conventional water treatment processes (coagulation-sedimentation-filtration). Relative to the conventional processes alone, O(3)-BAC significantly improved the removal of turbidity, dissolved organic carbon, UV(254), NH(4)(+) and dissolved organic nitrogen from 98-99%, 58-72%, 31-53%, 16-93% and 35-74%, respectively, and enhanced the removal efficiency of the precursors for the measured DBPs. The conventional process was almost ineffective in removing the precursors of trichloronitromethane (TCNM) and dichloroacetamide (DCAcAm). Ozonation could not substantially reduce the formation of DCAcAm, and actually increased the formation potential of TCNM; it chemically altered the molecular structures of the precursors and increased the biodegradability of N-containing organic compounds. Consequently, the subsequent BAC filtration substantially reduced the formation of the both TCNM and DCAcAm, thus highlighting a synergistic effect of O(3) and BAC. Additionally, O(3)-BAC was effective at controlling the formation of the total organic halogen, which can be considered as an indicator of the formation of unidentified DBPs.

  6. Biological Hydrogen Production: Simultaneous Saccharification and Fermentation with Nitrogen and Phosphorus Removal from Wastewater Effluent (United States)


    energy intensive and completely dependent on fossil fuel: CH4 + H20-^CO + 3H2 (1) Hydrogen can also be produced by electrolysis , splitting water into...the WWTP discharge waters using the same biological process as used to generate hydrogen. Two reactor configurations were used, including a...hydrogen and simultaneously capture nitrogen and phosphorus. Two reactor configurations were tested as simultaneous saccharification and fermentation

  7. Biological technologies for the removal of sulfur containing compounds from waste streams: bioreactors and microbial characteristics. (United States)

    Li, Lin; Zhang, Jingying; Lin, Jian; Liu, Junxin


    Waste gases containing sulfur compounds, such as hydrogen sulfide, sulfur dioxide, thioethers, and mercaptan, produced and emitted from industrial processes, wastewater treatment, and landfill waste may cause undesirable issues in adjacent areas and contribute to atmospheric pollution. Their control has been an area of concern and research for many years. As alternative to conventional physicochemical air pollution control technologies, biological treatment processes which can transform sulfur compounds to harmless products by microbial activity, have gained in popularity due to their efficiency, cost-effectiveness and environmental acceptability. This paper provides an overview of the current biological techniques used for the treatment of air streams contaminated with sulfur compounds as well as the advances made in the past year. The discussion focuses on bioreactor configuration and design, mechanism of operation, insights into the overall biological treatment process, and the characterization of the microbial species present in bioreactors, their populations and their interactions with the environment. Some bioreactor case studies are also introduced. Finally, the perspectives on future research and development needs in this research area were also highlighted.

  8. Improved treatment approach for the removal of aromatic compounds using polymeric beads in Fenton pretreatment and biological oxidation. (United States)

    Ramteke, Lokeshkumar P; Gogate, Parag R


    An improved approach based on the use of iron-doped polymeric beads (IPB) as Fenton catalyst in the pretreatment and biomass-doped polymeric bead (BPB) in the biological oxidation has been reported for the removal of different aromatic mixtures present as pollutants in the aqueous solutions. Degradation has been investigated at fixed loading of IPB as 2.5 % weight basis and varying loading of hydrogen peroxide so as to understand the effect of oxidant loading on the extent of degradation. It has been observed that the maximum removal efficiency as 75.5, 81.4, and 59.1 % was obtained for the benzene-toluene-naphthalene-xylene (BTNX), benzene-toluene-ethylbenzene-xylene (BTEX), and benzene-toluene-naphthalene-p-nitrophenol (BTNp-NP) mixtures, respectively, at a 40-min pretreatment and optimum pH of 3.5. The biodegradability index was also observed in the favorable range of 0.4 to 0.5 after the pretreatment at optimum H2O2 loading of 1.5 g L(-1). Maximum COD removal efficiency of 99.2, 99.3, and 99.6 % was obtained using the biological oxidation treatment for 40 h for the case of BTNX, BTEX, and BTNp-NP mixtures, respectively. Analysis of kinetic models revealed that degradation followed three distinct stages based on fitting of the three-stage model and BPB was found to be more efficient as compared to the primary activated sludge (PAS) and modified activated sludge (MAS). Reusability studies confirmed that both IPB and BPB were effective over many cycles giving stable performance during degradation without leaching of Fe(3+) ions into the solution.

  9. 污废水生物脱氮除磷技术研究进展%Research Status of Technologies for Nitrogen and Phosphorus Removal by Biological Processes

    Institute of Scientific and Technical Information of China (English)



      总结了目前城市污水生物脱氮除磷技术研究及应用进展,分析了脱氮除磷工艺机理及其特点,探讨了城市污水生物脱氮除磷工艺深入研究的方向。%This paper reviews the advances in the biological nitrogen and phosphorus removal technologies for municipal wastewater .The mechanism and characteristics of nitrogen and phosphorus removal processes are analyzed , and directions of studying the biological nitrogen and phosphorus removal technologies are also discussed .

  10. Kinetics of organic removal in fixed-bed aerobic biological reactor. (United States)

    Borghei, S M; Sharbatmaleki, M; Pourrezaie, P; Borghei, G


    The process kinetics of a lab-scale upflow aerobic immobilized biomass (UAIB) reactor using simulated sugar-manufacturing wastewater as feed was investigated. The experimental unit consisted of a 22l reactor filled with high porosity pumice stone. The UAIB reactor was tested under different organic loads and different hydraulic retention times (HRT) and the substrate loading removal rate was compared with prediction of Stover-Kincannon model, second-order model and the first order substrate removal model. After obtaining steady-state conditions, organic loading rate was increased from 750 to 4500 g COD/m(3) day to resemble wastewater from sugar production lines, and hydraulic retention time was decreased from 1 to 0.5 days, stepwise. Nine different operational conditions were applied changing these two parameters in a certain program. As a result of the calculations, Stover-Kincannon model and second-order model known as "Grau" model were found to be the most appropriate models for this reactor. Stover-Kincannon model and Grau second-order model gave high correlation coefficients, which were 99.7% and 99.4%, respectively. Therefore, these models could be used in predicting the behavior or design of the UAIB reactors.

  11. Diagnosing oceanic nutrient deficiency (United States)

    Moore, C. Mark


    The supply of a range of nutrient elements to surface waters is an important driver of oceanic production and the subsequent linked cycling of the nutrients and carbon. Relative deficiencies of different nutrients with respect to biological requirements, within both surface and internal water masses, can be both a key indicator and driver of the potential for these nutrients to become limiting for the production of new organic material in the upper ocean. The availability of high-quality, full-depth and global-scale datasets on the concentrations of a wide range of both macro- and micro-nutrients produced through the international GEOTRACES programme provides the potential for estimation of multi-element deficiencies at unprecedented scales. Resultant coherent large-scale patterns in diagnosed deficiency can be linked to the interacting physical-chemical-biological processes which drive upper ocean nutrient biogeochemistry. Calculations of ranked deficiencies across multiple elements further highlight important remaining uncertainties in the stoichiometric plasticity of nutrient ratios within oceanic microbial systems and caveats with regards to linkages to upper ocean nutrient limitation. This article is part of the themed issue 'Biological and climatic impacts of ocean trace element chemistry'.

  12. Plants Responses to Nutrients Follow the Saturation Kinetic Typical of Enzyme Systems: Biological, Economical and Environmental Implications

    Directory of Open Access Journals (Sweden)

    R. P. Lana


    Full Text Available Agricultural efficiency has been associated with high plant productivity. However, it is dependent on fertilizers, which are nonrenewable resources. Crop production response to fertilizers is hyperbolic, following the Michaelis-Menten model and the law of diminishing return. Data of crop production (barley, bean, corn, cotton, soybean and wheat as a function of nitrogen, phosphorus, and potassium fertilization were analyzed by Lineweaver-Burk data transformation (L-B, that allows to calculate the amount of a specific nutrient needed to reach half (ks or other percentages of the theoretical maximum response (kmax and the efficiency of fertilizer use (kg of grain/kg of fertilizer. The efficiency of fertilizer use presented exponential decay by increasing fertilization: 55 to 3; 63 to 5; and 47 to 1 kg of corn/kg of fertilizer, by increasing nitrogen, P2O5 and potassium from 40 to 200; 40 to 200; and 60 to 300 kg ha-1, respectively. The L-B can be an alternative to the linear-plateau and polynomial regression methods of recommendation of plant fertilization, in which the fertilizers recommendation should be based on their efficiency of use, avoiding losses of nutrients, environmental pollution, waste of nonrenewable natural resources, and reducing productive costs.


    Institute of Scientific and Technical Information of China (English)

    TAKAYA; Naoki; SHOUN; Hirofumi


    Denitrificationis a biological processin which nitrateand/or nitrite is reduced to gaseous nitrogen,dinitrogen(N2)or nitrous oxide(N2O)while carbon dioxide is thesecond gaseous product of the process.This is one of themain mechanisms of the global nitrogen cycle,and playsanimportant role as the reverse reaction of nitrogen fixa-tion in maintaining global environmental homeostasis[1].Denitrification has beenlongthought to be a unique char-acteristic of prokaryotes[2,3].Anumber of bacteria(suchasPseudomonas s...

  14. AOX removal from industrial wastewaters using advanced oxidation processes: assessment of a combined chemical-biological oxidation. (United States)

    Luyten, J; Sniegowski, K; Van Eyck, K; Maertens, D; Timmermans, S; Liers, Sven; Braeken, L


    In this paper, the abatement of adsorbable halogenated organic compounds (AOX) from an industrial wastewater containing relatively high chloride concentrations by a combined chemical and biological oxidation is assessed. For chemical oxidation, the O(3)/UV, H(2)O(2)/UV and photo-Fenton processes are evaluated on pilot scale. Biological oxidation is simulated in a 4 h respirometry experiment with periodic aeration. The results show that a selective degradation of AOX with respect to the matrix compounds (expressed as chemical oxygen demand) could be achieved. For O(3)/UV, lowering the ratio of O(3) dosage to UV intensity leads to a better selectivity for AOX. During O(3)-based experiments, the AOX removal is generally less than during the H(2)O(2)-based experiments. However, after biological oxidation, the AOX levels are comparable. For H(2)O(2)/UV, optimal operating parameters for UV and H(2)O(2) dosage are next determined in a second run with another wastewater sample.

  15. A Combined System for Biological Removal of Nitrogen and Carbon from Nylon-6 Production Wastewater

    Institute of Scientific and Technical Information of China (English)

    LIU Fang; LIU Guo-hua; TIAN Qing; ZHANG Man; CHEN Ji-hua


    A combined system consisting of hydrolysisacidification, denitrification and nitrification reactors wasused to remove carbon and nitrogen from the nylon - 6production wastewater, which was characterized by goodbiodegradability and high nitrogen concentration. Theinfluences of Chemical Oxygen Demand(COD) in theinfluent, recirculation ratio, Hydraulic Residence Time(HRT) and Dissolved Oxygen(DO) concentration on thesystem performances were investigated. From results itcould be seen that good performances have been achievedduring the overall experiments periods, and COD, TotalNitrogen(TN), NH+-N and Suspended Solids(SS) in theeffluent were 53, 16, 2 and 24 mg·L-1, respectively,which has satisfied the first standard of wastewaterdischarge established by Environmental Protection Agency(EPA) of China. Furthermore, results showed thatoperation factors, viz. COD in the influent, recirculationratio, HRT and DO concentration, all had importantinfluences on the system performances.


    Directory of Open Access Journals (Sweden)

    Bazhenov V. I. / Баженов Виктор Иванович


    Full Text Available The paper provides a mechanism for the biological purification of wastewater in the aeration tanks with nutrient removal in connection with simulation modeling, based on software GPS-X. The authors provide the example of zones design optimization for denitrification process MUCT achieved when N-NO3 = 0.3 mg/L. Presented is the typical block for biological treatment with nitrogen and phosphorus removal with flowrate 1140 m3/h due to one section of the aeration tank / Приводится механизм биологической очистки сточных вод в аэротенках с удалением биогенных элементов в связи с имитационным моделированием на базе расчетного комплекса GPS-X. Рассмотрен пример оптимизации размеров зоны денитрификации для процесса MUCT, достигнутом при N-NO3 = 0,3 мг/л. Представлен типовой проект блока биологической очистки с удалением азота и фосфора при расходе на одну секцию аэротенка 1140 м3/ч

  17. Effects of male removal on female reproductive biology in Ross' and Lesser Snow Geese (United States)

    Leschack, C.R.; Afton, A.D.; Alisauskas, R.T.


    We studied effects of mate removal on nesting and hatching success, incubation behavior, body mass, and post-hatch dispersal distance of female Ross' (Chen rossii) and Lesser Snow Geese (C. caerulescens caerulescens) at Karrak Lake. N.W.T., Canada. Male ge and widowed and paired control females were monitored through post-hatch dispersal. Nesting and hatching success did not differ between species or treatments (widowed vs paired) and averaged 77.5 ?? 3.8% and 64.0 ?? 3.6% (??SE), respectively. Paired females spent more time with their bills tucked (23.7 ?? 3.3% vs 9.1 ?? 4.0%) and less time alert (8.6 ?? 2.9% vs 22.9 ?? 3.5%) while on nests than did widowed females. Snow widowed females (31.1 ?? 4.7%) and Ross' widowed females (20.6 ?? 6.0%) generally spent more time each day in head-up alert than did Snow paired females (7.1 ?? 3.8%). Snow paired maleS (11.8 ?? 3.8%), Ross' paired females (9.4 ?? 3.6%), and Ross' paired males (7.9 ?? 3.6%). Body mass of paired and widowed female Ross' Geese did not differ at hatch or at time of post-hatch recapture; however, mean distance recaptured from the breeding colony was greater for paired (50.9 ?? 6.1 km) than for widowed females (27.3 ?? 6.6 km). Total mass gain (276 ?? 19 g) and rate of mass gain (8.4 ?? 0.5 g/day), from hatch until post-hatch recapture (33.1 ?? 1.2 days), were similar for widowed and paired female Ross' Geese. Male removal experiments in monogamous, precocial species generally have produced few effects on female nesting success or incubation behavior. We suggest that male parental care in arctic-nesting geese is more critical during laying and the post-hatch period than during incubation.

  18. Nitrate Removal from Wastewater through Biological Denitrification with OGA 24 in a Batch Reactor

    Directory of Open Access Journals (Sweden)

    Federico Rossi


    Full Text Available Nitrates pollution of waters is a worldwide problem and its remediation is a big challenge from the technical and the scientific point of view. One of the most used and promising cleaning techniques is the biological treatment of wastewaters operated by denitrifying bacteria. In this paper we begin a thorough study of denitrifying performances of the bacterium Azospira sp. OGA 24, recently isolated from the highly polluted Sarno river in the south of Italy. Here, the kinetics of nitrates consumption operated by bacteria in a specifically devised batch bioreactor, in anoxic condition and with acetate as the organic substrate, has been characterized. Experimental data were then used in a simplified model of a real wastewater treatment plant to find that OGA 24 can clean water with efficiency up to 90%. The denitrifying performances of OGA 24 match the requirements of Italian laws and make the bacterium suitable for its employment in treatment plants.

  19. Removal of pigments from molasses wastewater by combining micro-electrolysis with biological treatment method. (United States)

    Chen, Ben; Tian, Xiaofei; Yu, Lian; Wu, Zhenqiang


    Pigments in molasses wastewater (MWW) effluent, such as melanoidins, were considered as kinds of the most recalcitrant and hazardous colorant contaminants to the environment. In this study, de-coloring the MWW by a synergistic combination of micro-electrolysis with bio-treatment was performed. Aiming to a high de-colorization yield, levels of nutrition source supplies, MWW dilution ratio, and micro-electrolysis reaction time were optimized accordingly. For a diluted (50 %, v/v) MWW, an maximum overall de-colorization yield (97.1 ± 0.5 %, for absorbance at 475 nm) was achieved through the bio-electrolysis treatment. In electrolysis bio-treatment, the positive effect of micro-electrolysis was also revealed by a promoted growth of fungal biomass as well as activities of ligninolytic enzymes. Activities of lignin peroxidase, manganese peroxidase, and laccase were promoted by 111.2, 103.9, and 7.7 %, respectively. This study also implied that the bio-treatment and the micro-electrolysis had different efficiencies on removal of pigments with distinct polarities.

  20. Respirometry applied for biological nitrogen removal process; Aplicacion de la respirometria al tratamiento biologico para la eliminacion del nitrogeno

    Energy Technology Data Exchange (ETDEWEB)

    Serrano, E.


    In waste water treatment plants, the Biological Nitrogen Removal (BNR) has acquired a fundamental importance. The BNR processes are Nitrification ( aerobic) and Denitrification (anoxic). Since both processes are carried on living microorganisms, a lack of their bioactivity information might cause serious confusion about their control criteria and following up purposes. For this reason, the Re spirometry applied to those processes has reached an important role by getting an essential information in a timely manner through respiration rate measurements in static and dynamic modes and applications such as AUR (Ammonium Uptake Rate), Nitrification Capacity. RBCOD (Readily Biodegradable COD) as well as AUR related to SRT (Sludge age), RBCOD related to NUR (Specific Nitrate Uptake Rate) and others. By other side in this article we have introduced a not very well known applications related to denitrification, about the methanol acclimatization and generated bioactivity. (Author) 6 refs.

  1. Gamma rays as an effective tool for removing undesirable color without adverse changes in biological activities of red beet extracts (United States)

    Lee, Seung Sik; Lee, Eun Mi; Hong, Sung Hyun; Bai, Hyoung-Woo; Lee, In Chul; Chung, Byung Yeoup


    The ethanolic extracts of red beet (Beta vulgaris L.) hairy root were used to investigate the removal of color and improvement of biological activity for enhanced industrial applications. The extracts were exposed to gamma rays ranging from 2.5 to 30 kGy. The red beet hairy root is composed of two major red-colorants, betanin and isobetanin. Gamma ray radiation at 5 kGy remarkably reduced the levels of the major colorants by 94% and the reddish color was eliminated by doses greater than 10 kGy. Color removal was likely due to the gamma ray radiolysis of ethanol. Although details on the mechanism responsible for the decay of the chromophore have not been entirely determined, our results suggest that the free radicals that are produced during this process are capable of destroying the chromophore group in isobetanin, thus bleaching the substrate solution. In spite of the degradation of the major colorants, the biological activities of constituents of the extract such as DPPH radical scavenging and tyrosinase inhibition were negligibly affected by the gamma ray radiation up to 20 kGy. The antioxidant activity was 92.7% in control samples and 90.0-92.0% in irradiated samples (2.5-20 kGy), and a slight decrease to 87.5% was observed for gamma ray radiation at 30 kGy. In addition, tyrosinase inhibition activity has also the same pattern; the activity is slightly increased from 50.7% of control to 49.1-52.8% of irradiated samples (2.5-20 kGy) with a 46.8% at 30 kGy.

  2. Biological Removal of Propylene Glycol from Wastewater and its Degradation in Soil by the Activated Sludge Consortia

    Directory of Open Access Journals (Sweden)

    G.R Moussavi


    Full Text Available "n "nBackground and Objectives : Propylene glycol is the main compound of anti-freezing chemicals. A significant amount of propylene glycol is released to the environment after application and contaminates the soil. The main objective of this study was to determine the biological removal of propylene glycol from wastewater and its degradation in soil by the isolated bacteria from activated sludge process."nMaterials and Methods: In the present study, the sludge taken from the return flow in a local activated sludge treatment system was used as the initial seed. The performance of the bioreactor in treating the wastewater was evaluated at four different retention times of 18, 12, 6 and 4 h all with the inlet COD concentration of 1000 mg/L. This phase lasted around 4 months. Then, a part of the adapted microorganisms were transported from the bioreactor to the soil which was synthetically contaminated to the propylene glycol."nResults: The average of propylene glycol removal efficiency from the wastewater in detention times of 18, 12, 8 and 4 h in steady state conditions was 98.6%, 97.1%, 86.4% and 62.2% respectively. Also, the maximum degradation in soil was found to be 97.8%."nConclusion: According to the results obtained from this study, it appears that propylene glycol is inherently well biodegradable and can be biodegraded in liquid phase and soil after a short period of adaptation.

  3. Microbial communities involved in enhanced biological phosphorus removal from wastewater--a model system in environmental biotechnology. (United States)

    Nielsen, Per Halkjær; Saunders, Aaron Marc; Hansen, Aviaja Anna; Larsen, Poul; Nielsen, Jeppe Lund


    Enhanced biological phosphorus removal (EBPR) is one of the most advanced and complicated wastewater treatment processes applied today, and it is becoming increasingly popular worldwide as a sustainable way to remove and potentially reuse P. It is carried out by complex microbial communities consisting primarily of uncultured microorganisms. The EBPR process is a well-studied system with clearly defined boundaries which makes it very suitable as a model ecosystem in microbial ecology. Of particular importance are the transformations of C, N, and P, the solid-liquid separation properties and the functional and structural stability. A range of modern molecular methods has been used to study these communities in great detail including single cell microbiology, various -omics methods, flux analyses, and modeling making this one of the best studied microbial ecosystems so far. Recently, an EBPR core microbiome has been described and we present in this article some highlights and show how this complex microbial community can be used as model ecosystem in environmental biotechnology.

  4. Occurrence, behavior and removal of typical substituted and parent polycyclic aromatic hydrocarbons in a biological wastewater treatment plant. (United States)

    Qiao, Meng; Qi, Weixiao; Liu, Huijuan; Qu, Jiuhui


    Wastewater treatment plant (WWTP) effluent is the major source for substituted polycyclic aromatic hydrocarbons (SPAHs) to the receiving rivers, as well as the parent PAHs. Some of the SPAHs showed higher toxicities and levels than their parent PAHs. The occurrence and behavior of typical SPAHs were investigated in a representative biological WWTP in Beijing, China. Methyl PAHs (MPAHs) (149-221 ng/L in the influent; 29.6-56.3 ng/L in the effluent; 202-375 ng/g in the activated sludge), oxygenated PAHs (OPAHs) (139-155 ng/L; 69.9-109 ng/L; 695-1533 ng/g) and PAHs (372-749 ng/L; 182-241 ng/L; 2402-3321 ng/g) existed, but nitrated PAHs (NPAHs) were not detected. 2-Methylnaphthalene, anthraquinone, 9-fluorenone and 2-methylanthraquinone were the predominant SPAHs. OPAHs were deduced to be formed from PAHs especially during summer, based on the ratios variation and removal efficiencies of the two seasons, and the surplus mass in the outflows. Low molecular weight compounds (2-3 rings) might be mainly removed by mineralization/transformation and adsorption in the anaerobic unit, and by volatilization in the aerobic unit. High molecular weight compounds (4-6 rings) might be mainly removed by adsorption in the anaerobic unit. The total outflows of SPAHs and PAHs were 66 g/d in summer and 148 g/d in winter from the WWTP to the receiving river. The percentage of OPAHs was higher in summer than in winter.

  5. Removing the center from computing: biology's new mode of digital knowledge production. (United States)

    November, Joseph


    This article shows how the USA's National Institutes of Health (NIH) helped to bring about a major shift in the way computers are used to produce knowledge and in the design of computers themselves as a consequence of its early 1960s efforts to introduce information technology to biologists. Starting in 1960 the NIH sought to reform the life sciences by encouraging researchers to make use of digital electronic computers, but despite generous federal support biologists generally did not embrace the new technology. Initially the blame fell on biologists' lack of appropriate (i.e. digital) data for computers to process. However, when the NIH consulted MIT computer architect Wesley Clark about this problem, he argued that the computer's quality as a device that was centralized posed an even greater challenge to potential biologist users than did the computer's need for digital data. Clark convinced the NIH that if the agency hoped to effectively computerize biology, it would need to satisfy biologists' experimental and institutional needs by providing them the means to use a computer without going to a computing center. With NIH support, Clark developed the 1963 Laboratory Instrument Computer (LINC), a small, real-time interactive computer intended to be used inside the laboratory and controlled entirely by its biologist users. Once built, the LINC provided a viable alternative to the 1960s norm of large computers housed in computing centers. As such, the LINC not only became popular among biologists, but also served in later decades as an important precursor of today's computing norm in the sciences and far beyond, the personal computer.

  6. The testing of several biological and chemical coupled treatments for Cibacron Red FN-R azo dye removal. (United States)

    García-Montaño, Julia; Domènech, Xavier; García-Hortal, José A; Torrades, Francesc; Peral, José


    Several biological and chemical coupled treatments for Cibacron Red FN-R reactive azo dye degradation have been evaluated. Initially, a two-stage anaerobic-aerobic biotreatment has been assessed for different dye concentrations (250, 1250 and 3135 mg l(-1)). 92-97% decolourisation was attained during the anaerobic digestion operating in batch mode. However, no dissolved organic carbon (DOC) removal neither biogas production was observed during the process, indicating that no methanogenesis occurred. Additionally, according to Biotox and Zahn-Wellens assays, the anaerobically generated colourless solutions (presumably containing the resulting aromatic amines from azo bond cleavage) were found to be more toxic than the initial dye as well as aerobically non-biodegradable, thus impeding the anaerobic-aerobic biological treatment. In a second part, the use of an advanced oxidation process (AOP) like photo-Fenton or ozonation as a chemical post-treatments of the anaerobic process has been considered for the complete dye by-products mineralisation. The best results were obtained by means of ozonation at pH 10.5, achieving a global 83% mineralisation and giving place to a final harmless effluent. On the contrary, the tested photo-Fenton conditions were not efficient enough to complete oxidation.

  7. Hydrophobic organic chemicals (HOCs) removal from biologically treated landfill leachate by powder-activated carbon (PAC), granular-activated carbon (GAC) and biomimetic fat cell (BFC). (United States)

    Liyan, Song; Youcai, Zhao; Weimin, Sun; Ziyang, Lou


    Biological pretreatment efficiently remove organic matter from landfill leachate, but further removal of refractory hydrophobic organic chemicals (HOCs) is hard even with advanced treatment. In this work, three-stage-aged refuse bioreactor (ARB) efficiently removed chemical oxygen demand (COD) and biochemical oxygen demand (BOD) of fresh leachate produced in Shanghai laogang landfill, from 8603 to 451 mg L(-1) and 1368 to 30 mg L(-1), respectively. In downstream treatment, 3 g L(-1) powder-activated carbon (PAC), granular-activated carbon (GAC) and biomimetic fat cell (BFC) removed 89.2, 73.4 and 81.1% HOCs, but only 24.6, 19.1 and 8.9% COD, respectively. Through the specific HOCs accumulation characteristics of BFC, about 11.2% HOCs with low molecular weight (effluent exhibited a wide molecular weight distribution (34-514,646 Da). These constitutes are derived from both autochthonous and allochthonous matters as well as biological activities.

  8. Evaluation of Fenton Oxidation Process Coupled with Biological Treatment for the Removal of Reactive Black 5 from Aqueous Solution

    Directory of Open Access Journals (Sweden)

    Pegah Bahmani


    Full Text Available Biodegradation of azo dyes is difficult due to their complex structures and low BOD to COD ratios. In the present study, the efficiency of using Fenton’s reagent (H2O2 + Fe2+ as a pretreatment process to enhance microbial transformation of reactive black 5 (RB5 in an aqueous system was evaluated. The RB5 with an initial concentration of 250 mg/L was decolorized up to 90% in 60 h by using a bacterial consortium. Fenton’s reagent at a Fe2+ concentration of 0.5 mM and H2O2 concentration of 2.9 mM (molar ratio, 1:5.8 was most effective for decolorization at pH = 3.0. The extent of RB5 removal by the combined Fenton–biotreatment was about 2 times higher than that of biotreatment alone. The production of some aromatic amines intermediates implied partial mineralization of the RB5 in Fenton treatment alone; in addition, decreasing of GC-MS peaks suggested that dearomatization occurred in Fenton-biological process. Fenton pretreatment seems to be a cost–effective option for the biotreatment of azo dyes, due mainly to the lower doses of chemicals, lower sludge generation, and saving of time. Our results demonstrated positive effects of inoculating bacterial consortium which was capable of dye biodegradation with a Fenton’s pretreatment step as well as the benefits of low time required for the biological process. In addition, the potential of field performance of Fenton-biological process because of using bacterial consortium is an other positive effect of it.

  9. Sequential electrochemical/biological treatment for the removal of 2,6-dichlorophenol from synthetic wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Polcaro, A.M.; Palmas, S.; Lallai, A. [Cagliari Univ., Cagliari (Italy). Dipt. di Ingegneria Chmica e Materiali


    The paper examines the effect of chloride on the oxidation of 2,6-dichlorophenol (DCP) performed at TiO{sub 2}/RuO{sub 2} DSA (Registered) anodes, which are specific catalysts for chlorine evolution. The results indicate that chlorine/hypochlorite originating from chloride oxidation in certain favourable conditions reacts with the organic substrate at the diffusion layer near the anode, accelerating the mass transfer of the reactant towards the electrode surface. When the bulk concentration of organic substrate has become very low, the oxidising, species can accumulate in the bulk solution where the accomplishment of the oxidation of residual reactant and of its intermediates takes place. Solutions which also contained glucose were electrolysed in order to verify the high level of selectivity of DCP oxidation with respect to a biodegradable substrate: glucose was found to be unchanged up to nearly complete elimination of DCP. The toxicity of the solution was sufficiently reduced to reach values compatible with the subsequent biological treatment. [Italian] Il lavoro esamina l'influenza della presenza di cloruri nella ossidazione del 2,6-diclorofenolo (DCP) su anodi di DSA (Registered) a base di TiO{sub 2}/RuO{sub 2}, specifici catalizzatori dell'evoluzione del cloro. I risultati indicano che i prodotti di ossidazione del cloruro che si ottengono in adatte condizioni sperimentali, reagiscono con il substrato organico nello strato di diffusione adiacente all'anodo, accelerando il trasferimento di materia dell'organico verso la superficie dell'elettrodo. Quando la concentrazione di DCP nella massa e' diventata molto bassa l'ossidante prodotto puo' accumularsi nella massa della soluzione dove ha luogo il completamento dell'ossidazione del DCP residuo e degli intermedi prodotti. Sono state inoltre sottoposte ad elettrolisi alcune soluzioni di DCP contenenti anche glucosio. I risultati hanno permesso di verificare che il

  10. Nutrient recycling of sorghum straw and soil biological attributes in Eastern Amazon Reciclagem de nutrientes da palhada de sorgo e atributos biológicos do solo na Amazônia Oriental

    Directory of Open Access Journals (Sweden)

    Patrícia Ribeiro Maia


    Full Text Available The microbial biomass and activity are biological indicators sensitive to environmental changes caused by agricultural use and can provide important information for the planning of adequate land use. The objective of this research was to evaluate the nutrient recycling, persistence, and biological attributes of sorghum straw in Oxisol as a function of soil management systems. The experiment was carried out at the Federal Rural University of Amazonia in randomized block design with 3 x 2 factorial and four replicates. Three sorghum hybrids and two soil management systems were the factors used to assess straw decomposition. In order to evaluate the biological attributes, a 2 x 2 factorial experiment with four replicates was carried out using two soil management systems and two sampling dates. Total organic carbon (TOC, carbon in the soil microbial biomass (C-SMB, C-SMB/TOC ratio, basal respiration and metabolic quotient (qCO2 were investigated. The Qualimax hybrid presented the highest C/N ratio (55 and longer straw persistence in soil after 120 days of management (35%. The highest TOC, C-SMB, C-SMB/TOC ratio, and basal respiration and the smallest qCO2 were observed during the rainy season and in the no-till system.A atividade e biomassa microbiana são indicadores biológicos sensíveis a alterações ambientais decorrentes do uso agrícola, podendo fornecer informações importantes para o uso adequado do solo. Objetivou-se, com este trabalho, avaliar a ciclagem de nutrientes, atributos biológicos e a persistência da palhada de sorgo em um Latossolo Amarelo distrófico, em função de sistemas de manejo do solo. O experimento foi realizado na Universidade Federal Rural da Amazônia, em um delineamento em blocos casualizados, com fatorial 3 x 2 e quatro repetições. Os fatores foram: três híbridos de sorgo e dois sistemas de manejo do solo, para avaliar a decomposição da palhada. Para avaliar os atributos biológicos, um experimento com

  11. Summary and anticipated responses to Elwha River dam removal: Chapter 9 in Coastal habitats of the Elwha River, Washington--biological and physical patterns and processes prior to dam removal (United States)

    Gelfenbaum, Guy; Duda, Jeffrey J.; Warrick, Jonathan A.; Duda, Jeffrey J.; Warrick, Jonathan A.; Magirl, Christopher S.


    Starting in September 2011, the removal of two large dams on the Elwha River will begin an unprecedented river restoration project because of the size of the dams, the volume of sediment released, the pristine watershed upstream of the dam sites, and the potential for renewing salmon populations. Ecosystem studies of the Elwha watershed indicate that the effects of almost 100 years of damming are measurable and of consequence. These effects include smaller spawning salmon populations, massive sediment retention behind the dams, coarsening of the riverbed downstream of the dams, low nutrient concentrations in the river waters, and coastal erosion that has accelerated markedly with time. During

  12. Kinetic Interpretation of Nitrogen Removal in Pilot Scale Experiments

    DEFF Research Database (Denmark)

    Harremoës, Poul; Sinkjær, Ole


    with biological and chemical phosphorus removal. Nitrification and denitrification rates have been measured in batch tests on activated sludge extracted from the pilot plants and by measuring transient concentrations during the alternating mode of operation in the aerobic and anoxic tanks. The data were......Pilot plant experiments have been performed over a period of four years in order to establish an experimental basis for the upgrading of the treatment plants of The City of Copenhagen to nutrient removal. The choice of design is the alternating mode of operating biological nitrogen removal...

  13. 生物反硝化除磷技术研究进展%Advances in Research of Phosphorus Removal Technology for Biological Denitrification Processes

    Institute of Scientific and Technical Information of China (English)

    姜鸣; 张静慧; 宫飞蓬; 周军; 甘一萍; 李军


    综述了反硝化除磷技术的基本理论,各种反硝化除磷工艺的特点,反硝化除磷微生物学的研究情况以及对其机理与数学模型研究的发展.%The basic theories of biological denitrifying phosphorus removal, characteristic of various process, the research status of biological denitrifying phosphorus removal and so on were introduced.

  14. The fed-batch principle for the molecular biology lab: controlled nutrient diets in ready-made media improve production of recombinant proteins in Escherichia coli. (United States)

    Krause, Mirja; Neubauer, Antje; Neubauer, Peter


    While the nutrient limited fed-batch technology is the standard of the cultivation of microorganisms and production of heterologous proteins in industry, despite its advantages in view of metabolic control and high cell density growth, shaken batch cultures are still the standard for protein production and expression screening in molecular biology and biochemistry laboratories. This is due to the difficulty and expenses to apply a controlled continuous glucose feed to shaken cultures. New ready-made growth media, e.g. by biocatalytic release of glucose from a polymer, offer a simple solution for the application of the fed-batch principle in shaken plate and flask cultures. Their wider use has shown that the controlled diet not only provides a solution to obtain significantly higher cell yields, but also in many cases folding of the target protein is improved by the applied lower growth rates; i.e. final volumetric yields for the active protein can be a multiple of what is obtained in complex medium cultures. The combination of the conventional optimization approaches with new and easy applicable growth systems has revolutionized recombinant protein production in Escherichia coli in view of product yield, culture robustness as well as significantly increased cell densities. This technical development establishes the basis for successful miniaturization and parallelization which is now an important tool for synthetic biology and protein engineering approaches. This review provides an overview of the recent developments, results and applications of advanced growth systems which use a controlled glucose release as substrate supply.

  15. Weed management, training, and irrigation practices for organic production of trailing blackberry: III. Accumulation and removal of aboveground biomass, carbon, and nutrients (United States)

    The effects of various production practices on biomass, C, and nutrient content, accumulation, and loss were assessed over 2 years in a mature organic trailing blackberry (Rubus L. subgenus Rubus, Watson) production system. Treatments included two irrigation options (no irrigation after harvest and ...

  16. Contribution of Wastewater Treatment Plant Effluents to Nutrient Dynamics in Aquatic Systems: A Review (United States)

    Carey, Richard O.; Migliaccio, Kati W.


    Excessive nutrient loading (considering nitrogen and phosphorus) is a major ongoing threat to water quality and here we review the impact of nutrient discharges from wastewater treatment plants (WWTPs) to United States (U.S.) freshwater systems. While urban and agricultural land uses are significant nonpoint nutrient contributors, effluent from point sources such as WWTPs can overwhelm receiving waters, effectively dominating hydrological characteristics and regulating instream nutrient processes. Population growth, increased wastewater volumes, and sustainability of critical water resources have all been key factors influencing the extent of wastewater treatment. Reducing nutrient concentrations in wastewater is an important aspect of water quality management because excessive nutrient concentrations often prevent water bodies from meeting designated uses. WWTPs employ numerous physical, chemical, and biological methods to improve effluent water quality but nutrient removal requires advanced treatment and infrastructure that may be economically prohibitive. Therefore, effluent nutrient concentrations vary depending on the particular processes used to treat influent wastewater. Increasingly stringent regulations regarding nutrient concentrations in discharged effluent, along with greater freshwater demand in populous areas, have led to the development of extensive water recycling programs within many U.S. regions. Reuse programs provide an opportunity to reduce or eliminate direct nutrient discharges to receiving waters while allowing for the beneficial use of reclaimed water. However, nutrients in reclaimed water can still be a concern for reuse applications, such as agricultural and landscape irrigation.

  17. Relating dynamic conditions to the performance of biological rapid sand filters used to remove ammonium, iron, and manganese from drinking water

    DEFF Research Database (Denmark)

    Lee, Carson; Albrechtsen, Hans-Jørgen; Smets, Barth F.;

    and media samples were collected throughout the depth of the column and over the operational cycle of the columns. Substrate analysis included ammonium, nitrite, nitrate, iron, and manganese. Qpcr analysis were also performed to quantify ammonium oxidizing bacteria (AOBs), ammonium oxidizing archea ( AOAs...... on the roles of both Ammonium oxidizing bacteria (AOBs) and Ammonium oxidizing archea (AOAs) in the biological removal of ammonium in rapid sand filters and how varying substrate loadings and operating conditions can affect the biological performance of these filters....

  18. Evaluation of membrane bioreactor process capabilities to meet stringent effluent nutrient discharge requirements. (United States)

    Fleischer, Edwin J; Broderick, Thomas A; Daigger, Glen T; Fonseca, Anabela D; Holbrook, R David; Murthy, Sudhir N


    A six-stage membrane bioreactor (MBR) pilot plant was operated to determine and demonstrate the capability of this process to produce a low-nutrient effluent, consistent with the nutrient reduction goals for the Chesapeake Bay. Biological nitrogen removal was accomplished using a multistage configuration with an initial anoxic zone (using the carbon in the influent wastewater), an aerobic zone (where nitrification occurred), a downstream anoxic zone (where methanol was added as a carbon source), and the aerated submerged membrane zone. The capability to reliably reduce effluent total nitrogen to less than 3 mg/L as nitrogen (N) was demonstrated. A combination of biological (using an initial anaerobic zone) and chemical (using alum) phosphorus removal was used to achieve effluent total phosphate concentrations reliably less than 0.1 mg/L as phosphorus (P) and as low as 0.03 mg/L as P. Alum addition also appeared to enhance the filtration characteristics of the MBR sludge and to reduce membrane fouling. Aeration of the submerged membranes results in thickened sludge with a high dissolved oxygen concentration (approaching saturation), which can be recycled to the main aeration zone rather than to an anoxic or anaerobic zone to optimize biological nutrient removal. Biological nutrient removal was characterized using the International Water Association Activated Sludge Model No. 2d. The stoichiometry of chemical phosphorus removal was also consistent with conventional theory and experience. The characteristics of the solids produced in the MBR were compared with those of a parallel full-scale conventional biological nitrogen removal process and were generally found to be similar. These results provide valuable insight to the design and operating characteristics of MBRs intended to produce effluents with very low nutrient concentrations.

  19. Microfauna communities as performance indicators for an A/O Shortcut Biological Nitrogen Removal moving-bed biofilm reactor. (United States)

    Canals, O; Salvadó, H; Auset, M; Hernández, C; Malfeito, J J


    The microfauna communities present in the mixed liquor and biofilm of an Anoxic/Oxic Shortcut Biofilm Nitrogen Removal moving-bed biofilm process were characterised in order to optimise process control through the use of bioindicators. The system operated at high ammonium concentrations, with an average of 588 ± 220 mg N-NH4(+) L(-1) in the influent, 161 ± 80 mg L(-1) in the anoxic reactor and 74 ± 71.2 mg L(-1) in the aerobic reactor. Up to 20 different taxa were identified, including ciliates (4), flagellates (11), amoebae (4) and nematodes (1). Compared to conventional wastewater treatment processes (WWTPs), this process can be defined as a flagellates-predominant system with a low diversity of ciliates. Flagellates were mainly dominant in the mixed liquor, demonstrating high tolerance to ammonium and the capacity for survival over a long time under anoxic conditions. The data obtained provide interesting values of maximum and minimum tolerance ranges to ammonium, nitrates and nitrites for the ciliate species Cyclidium glaucoma, Colpoda ecaudata, Vorticella microstoma-complex and Epistylis cf. rotans. The last of these was the only ciliate species that presented a constant and abundant population, almost exclusively in the aerobic biofilm. Epistylis cf. rotans dynamics showed a high negative correlation with ammonium variations and a positive correlation with ammonium removal efficiency. Hence, the results indicate that Epistylis cf. rotans is a good bioindicator of the nitrification process in this system. The study of protozoan communities in unexplored WWTPs sheds light on species ecology and their role under conditions that have been little studied in WWTPs, and could offer new biological management tools.

  20. Identification of glucose-fermenting bacteria in a full-scale enhanced biological phosphorus removal plant by stable isotope probing. (United States)

    Nielsen, Jeppe Lund; Nguyen, Hien; Meyer, Rikke Louise; Nielsen, Per Halkjær


    Microbiology in wastewater treatment has mainly been focused on problem-causing filamentous bacteria or bacteria directly involved in nitrogen and phosphorus removal, and to a lesser degree on flanking groups, such as hydrolysing and fermenting bacteria. However, these groups constitute important suppliers of readily degradable substrates for the overall processes in the plant. This study aimed to identify glucose-fermenting bacteria in a full-scale enhanced biological phosphorus removal (EBPR) wastewater treatment plant (WWTP), and to determine their abundance in similar WWTPs. Glucose-fermenting micro-organisms were identified by an in situ approach using RNA-based stable isotope probing. Activated sludge was incubated anaerobically with (13)C(6)-labelled glucose, and (13)C-enriched rRNA was subsequently reverse-transcribed and used to construct a 16S rRNA gene clone library. Phylogenetic analysis of the library revealed the presence of two major phylogenetic groups of gram-positive bacteria affiliating with the genera Tetrasphaera, Propionicimonas (Actinobacteria), and Lactococcus and Streptococcus (Firmicutes). Specific oligonucleotide probes were designed for fluorescence in situ hybridization (FISH) to specifically target the glucose-fermenting bacteria identified in this study. The combination of FISH with microautoradiography confirmed that Tetrasphaera, Propionicimonas and Streptococcus were the dominant glucose fermenters. The probe-defined fermenters were quantified in 10 full-scale EBPR plants and averaged 39 % of the total biovolume. Tetrasphaera and Propionicimonas were the most abundant glucose fermenters (average 33 and 4 %, respectively), while Streptococcus and Lactococcus were present only in some WWTPs (average 1 and 0.4 %, respectively). Thus the population of actively metabolizing glucose fermenters seems to occupy a relatively large component of the total biovolume.

  1. 人工湿地土壤微生物生物量碳与污水净化效果的关系%Relationship of Soil Microbial Biomass Carbon and Nutrient Removal Rates in Constructed Wetlands

    Institute of Scientific and Technical Information of China (English)

    王萌; 许新; 陈章和


    微生物在人工湿地污水净化过程中发挥着重要作用,微生物生物量碳是微生物的重要表征之一.为探讨人工湿地土壤微生物量碳与污水净化效果的关系,以表面流人工湿地为研究对象,分别研究了不同植物人工湿地土壤微生物生物量碳和净化效果的时空变化及其相关性.结果显示,4种植物湿地表层(0-5 cm)微生物生物量碳极显著高于深层(15-20 cm)的测量值(P<0.01).人工湿地污染物去除效果与微生物生物量碳具有相同的季节变化规律,都呈单峰型的季节格局,夏秋季较高,冬春季较低.微生物生物量碳与人工湿地COD、BOD5和TN的去除呈显著正相关(P<0.05).水鬼蕉湿地具有较高的微生物生物量碳,而污染物去除率一般较低,这表明不同湿地微生物生物量碳与污染物去除率的相关性呈现不确定性.%Soil microorganisms are involved in all the biochemical processes which occur in soils, and they play a vital role in wastewater purification. Microbial biomass carbon is an important indicator of soil fertility, so we guess it is probably closely related to wastewater purification. For understanding whether relationship between nutrient removal rates and microbial biomass carbon existed, monoculture constructed wetlands of four plant species (Ph rag mites australis Trin. ex Steud., Hymenocallis littoralis (Jack.) Salisb., Canna indica Linn., Cyperus flabelliformis Rottb.) were built, and during a 2-month period, microbial biomass carbon and nutrient removal rates were measured. The results indicated that microbial biomass carbon in surface soil (0-5 cm) was significantly higher (P<0.01) than that in the deeper soil (15-20 cm). Both microbial biomass carbon and nutrient removal rates were higher during summer and autumn and lower during spring and winter. The removal rates of COD, BOD5 and total nitrogen were significantly correlated with microbial biomass carbon (P<0.05). In addition

  2. Biological elimination phosphorus; Eliminacion biologia de fosforo

    Energy Technology Data Exchange (ETDEWEB)

    Carrera, J.; Vicent, T.; Lafuente, J. [Universitat Autonoma de Barcelona (Spain)


    Phosphorus is the main limiting nutrient in the eutrophication process, and therefore its removal from the aquatic medium is indispensable. Biological Phosphorous Removal is a more efficient and convenient process compared with the classical chemical precipitation, due to a reduction of chemical reagents and sludge production. Moreover, it represents energy save since the sludge produced can be reused for agriculture purposes. In this paper bibliographic hypothesis about the metabolic pathways of the phosphorous accumulating organisms are widely and accurate reviewed and the above mentioned environmental benefits of the Biological Phosphorous Removal are reported. (Author) 22 refs.

  3. The Effect of Holder Pasteurization on Nutrients and Biologically-Active Components in Donor Human Milk: A Review. (United States)

    Peila, Chiara; Moro, Guido E; Bertino, Enrico; Cavallarin, Laura; Giribaldi, Marzia; Giuliani, Francesca; Cresi, Francesco; Coscia, Alessandra


    When a mother's milk is unavailable, the best alternative is donor milk (DM). Milk delivered to Human Milk Banks should be pasteurized in order to inactivate the microbial agents that may be present. Currently, pasteurization, performed at 62.5 °C for 30 min (Holder Pasteurization, HoP), is recommended for this purpose in international guidelines. Several studies have been performed to investigate the effects of HoP on the properties of DM. The present paper has the aim of reviewing the published papers on this topic, and to provide a comparison of the reported variations of biologically-active DM components before and after HoP. This review was performed by searching the MEDLINE, EMBASE, CINHAL and Cochrane Library databases. Studies that clearly identified the HoP parameters and compared the same DM samples, before and after pasteurization, were focused on. A total of 44 articles satisfied the above criteria, and were therefore selected. The findings from the literature report variable results. A possible explanation for this may be the heterogeneity of the test protocols that were applied. Moreover, the present review spans more than five decades, and modern pasteurizers may be able to modify the degradation kinetics for heat-sensitive substances, compared to older ones. Overall, the data indicate that HoP affects several milk components, although it is difficult to quantify the degradation degree. However, clinical practices demonstrate that many beneficial properties of DM still persist after HoP.

  4. Coastal and lower Elwha River, Washington, prior to dam removal--history, status, and defining characteristics: Chapter 1 in Coastal habitats of the Elwha River, Washington--biological and physical patterns and processes prior to dam removal (United States)

    Duda, Jeffrey J.; Warrick, Jonathan A.; Magirl, Christopher S.; Duda, Jeffrey J.; Warrick, Jonathan A.; Magirl, Christopher S.


    Characterizing the physical and biological characteristics of the lower Elwha River, its estuary, and adjacent nearshore habitats prior to dam removal is essential to monitor changes to these areas during and following the historic dam-removal project set to begin in September 2011. Based on the size of the two hydroelectric projects and the amount of sediment that will be released, the Elwha River in Washington State will be home to the largest river restoration through dam removal attempted in the United States. Built in 1912 and 1927, respectively, the Elwha and Glines Canyon Dams have altered key physical and biological characteristics of the Elwha River. Once abundant salmon populations, consisting of all five species of Pacific salmon, are restricted to the lower 7.8 river kilometers downstream of Elwha Dam and are currently in low numbers. Dam removal will reopen access to more than 140 km of mainstem, flood plain, and tributary habitat, most of which is protected within Olympic National Park. The high capture rate of river-borne sediments by the two reservoirs has changed the geomorphology of the riverbed downstream of the dams. Mobilization and downstream transport of these accumulated reservoir sediments during and following dam removal will significantly change downstream river reaches, the estuary complex, and the nearshore environment. To introduce the more detailed studies that follow in this report, we summarize many of the key aspects of the Elwha River ecosystem including a regional and historical context for this unprecedented project.

  5. Influence of phenol on ammonia removal in an intermittent aeration bioreactor treating biologically pretreated coal gasification wastewater. (United States)

    Xu, Chunyan; Han, Hongjun; Jia, Shengyong; Zhao, Qian


    A laboratory-scale intermittent aeration bioreactor was investigated to treat biologically pretreated coal gasification wastewater that was mainly composed of NH3-N and phenol. The results showed that increasing phenol loading had an adverse effect on NH3-N removal; the concentration in effluent at phenol loading of 40mgphenol/(L·day) was 7.3mg/L, 36.3% of that at 200mg phenol/(L·day). The enzyme ammonia monooxygenase showed more sensitivity than hydroxylamine oxidoreductase to the inhibitory effect of phenol, with 32.2% and 10.5% activity inhibition, respectively at 200mg phenol/(L·day). Owing to intermittent aeration conditions, nitritation-type nitrification and simultaneous nitrification and denitrification (SND) were observed, giving a maximum SND efficiency of 30.5%. Additionally, ammonia oxidizing bacteria (AOB) and denitrifying bacteria were the main group identified by fluorescent in situ hybridization. However, their relative abundance represented opposite variations as phenol loading increased, ranging from 30.1% to 17.5% and 7.6% to 18.2% for AOB and denitrifying bacteria, respectively.

  6. Chemically enhanced primary treatment (CEPT) for removal of carbon and nutrients from municipal wastewater treatment plants: a case study of Shanghai. (United States)

    Wang, Hongtao; Li, Fengting; Keller, Arturo A; Xu, Ran


    With Chemically Enhanced Primary Treatment (CEPT) as the short-term process, the capacity of Bailonggang Wastewater Treatment Plant accounts for almost 25% of the total capacity of wastewater treatment in Shanghai, China. However, shortly after this plant was placed in operation in 2004, it was found that the effluent of CEPT couldn't meet the new national discharge criteria. Although the removal of phosphate is almost 80%, chemical oxygen demand (COD) and ammonia nitrogen (NH3-N) in the effluent is frequently found to exceed the standards. The primary goal of this research is to investigate the possibility of optimizing the CEPT to make it meet the discharge criteria before it is upgraded to a secondary treatment. An oxidant is adopted to remove NH3-N, and a high performance polyaluminum chloride (HP-PACl) is synthesized to enhance the removal of COD. It is found that HP-PACl improves the removal of COD, and the oxidant enhances NH3-N removal effectively. However, to meet the requirement of a newly implemented stricter discharge standard, it is necessary to upgrade this CEPT to a secondary treatment. The results of this study provide scientific evidence for the upgrade of the Bailonggang Wastewater Treatment Plant.

  7. Succession of benthos and nutrient removal rate in the hydroponic culture system; Shokubutsu suiko saibaikei ni okeru konken seibutsu no henka to eiyoen no jokyo

    Energy Technology Data Exchange (ETDEWEB)

    Aizaki, M. [National Inst. for Environmental Studies, Tsukuba (Japan); Nakazato, H. [Biox Corp., Tokyo (Japan)


    Such nutrients as nitrogen and phosphorus discharged into lakes and rivers can cause organic contamination as a result of eutrophication in water areas if they are left as they are. However, they can be re-utilized as resources if they are utilized more effectively. This paper reports a hydroponic organism filtering method as a promising method of utilization thereof. It also explains transition in organism phase in rhizosphere and a water purification experiment. Such suspended matters as phytoplanktons in raw water are filtered and captured by roots of plants; such small animals as tendipedidae and physia live symbiotically in the rhizosphere; their excrements and nutrients are absorbed into and utilized by plants; and coexistence is made possible between diverse water-front environments including terrestrial systems and diverse living organisms. Cresson cultivation, observation on transition in the benthos composition, and a lake water purification experiment were carried out at the Kasumigaura Lake experimental facility. Various findings were acquired such that, in order to attain diverse coexistences including those with natural enemies and well-ventilated environments, a water channel of larger than a certain size is required. Results were also obtained that can be expected as an effective technique that may be used in public water areas. 3 refs., 4 figs.

  8. Nitrate as an Oxidant in the Cathode Chamber of a Microbial Fuel Cell for Both Power Generation and Nutrient Removal Purposes

    DEFF Research Database (Denmark)

    Fang, Cheng; Min, Booki; Angelidaki, Irini


    density achieved was 7.2 mW m−2 with a 470 Ω resistor. Nitrate was reduced from an initial concentration of 49 to 25 mg (NO3−−N) L−1 during 42-day operation. The daily removal rate was 0.57 mg (NO3−–N) L−1 day−1 with a voltage generation of 96 mV. In the presence of Pt catalyst dispersed on cathode......, the cell voltage was significantly increased up to 450 mV and the power density was 117.7 mW m−2, which was 16 times higher than the value without Pt catalyst. Significant nitrate removal was also observed with a daily removal rate of 2 mg (NO3−–N) L−1 day−1, which was 3.5 times higher compared...... with the operation without catalyst. Nitrate was reduced to nitrite and ammonia in the liquid phase at a ratio of 0.6% and 51.8% of the total nitrate amount. These results suggest that nitrate can be successfully used as an oxidant for power generation without aeration and also nitrate removal from water in MFC...

  9. Nitrate as an oxidant in the cathode chamber of a microbial fuel cell for both power generation and nutrient removal purposes. (United States)

    Fang, Cheng; Min, Booki; Angelidaki, Irini


    Nitrate ions were used as the oxidant in the cathode chamber of a microbial fuel cell (MFC) to generate electricity from organic compounds with simultaneous nitrate removal. The MFC using nitrate as oxidant could generate a voltage of 111 mV (1,000 Ω) with a plain carbon cathode. The maximum power density achieved was 7.2 mW m(-2) with a 470 Ω resistor. Nitrate was reduced from an initial concentration of 49 to 25 mg (NO (3) (-) -N) L(-1) during 42-day operation. The daily removal rate was 0.57 mg (NO (3) (-) -N) L(-1) day(-1) with a voltage generation of 96 mV. In the presence of Pt catalyst dispersed on cathode, the cell voltage was significantly increased up to 450 mV and the power density was 117.7 mW m(-2), which was 16 times higher than the value without Pt catalyst. Significant nitrate removal was also observed with a daily removal rate of 2 mg (NO (3) (-) -N) L(-1) day(-1), which was 3.5 times higher compared with the operation without catalyst. Nitrate was reduced to nitrite and ammonia in the liquid phase at a ratio of 0.6% and 51.8% of the total nitrate amount. These results suggest that nitrate can be successfully used as an oxidant for power generation without aeration and also nitrate removal from water in MFC. However, control of the process would be needed to reduce nitrate to only nitrogen gas, and avoid further reduction to ammonia.

  10. Functional bacteria and process metabolism of the Denitrifying Sulfur conversion-associated Enhanced Biological Phosphorus Removal (DS-EBPR) system: An investigation by operating the system from deterioration to restoration. (United States)

    Guo, Gang; Wu, Di; Hao, Tianwei; Mackey, Hamish Robert; Wei, Li; Wang, Haiguang; Chen, Guanghao


    A sulfur conversion-associated Enhanced Biological Phosphorus (P) Removal (EBPR) system is being developed to cater for the increasing needs to treat saline/brackish wastewater resulting from seawater intrusion into groundwater and sewers and frequent use of sulfate coagulants during drinking water treatment, as well as to meet the demand for eutrophication control in warm climate regions. However, the major functional bacteria and metabolism in this emerging biological nutrient removal system are still poorly understood. This study was thus designed to explore the functional microbes and metabolism in this new EBPR system by manipulating the deterioration, failure and restoration of a lab-scale system. This was achieved by changing the mixed liquor suspended solids (MLSS) concentration to monitor and evaluate the relationships among sulfur conversion (including sulfate reduction and sulfate production), P removal, variation in microbial community structures, and stoichiometric parameters. The results show that the stable Denitrifying Sulfur conversion-associated EBPR (DS-EBPR) system was enriched by sulfate-reducing bacteria (SRB) and sulfide-oxidizing bacteria (SOB). These bacteria synergistically participated in this new EBPR process, thereby inducing an appropriate level of sulfur conversion crucial for achieving a stable DS-EBPR performance, i.e. maintaining sulfur conversion intensity at 15-40 mg S/L, corresponding to an optimal sludge concentration of 6.5 g/L. This range of sulfur conversion favors microbial community competition and various energy flows from internal polymers (i.e. polysulfide or elemental sulfur (poly-S(2-)/S(0)) and poly-β-hydroxyalkanoates (PHA)) for P removal. If this range was exceeded, the system might deteriorate or even fail due to enrichment of glycogen-accumulating organisms (GAOs). Four methods of restoring the failed system were investigated: increasing the sludge concentration, lowering the salinity or doubling the COD

  11. Composición y remoción nutrimental de frutos de mango 'Haden' y 'Tommy Atkins' bajo producción forzada Fruit nutrient composition and removal by 'Haden' and 'Tommy Atkins' mangos fruits under forced production

    Directory of Open Access Journals (Sweden)

    Adriana Mellado-Vázquez

    Full Text Available Para mejorar el manejo de la nutrición del mango y mantener la fertilidad del suelo es necesario conocer la composición nutrimental de los frutos así como la cantidad de nutrimentos removidos por la cosecha. En 2009 se realizó el presente estudio con los cvs. Haden y Tommy Atkins bajo producción forzada en el Valle de Apatzingán, Michoacán, México con los objetivos de: i determinar la composición nutrimental de los tejidos del fruto (epidermis, pulpa, testa y embrión; y ii cuantificar la cantidad de nutrimentos removida por la cosecha de los dos cultivares de mango. Se seleccionaron dos huertos comerciales de mango 'Haden' y dos de 'Tommy Atkins', con manejo del riego y tipo de suelo (Vertisol similares. En cada huerto se eligieron cinco árboles de los que se cosecharon dos frutos en madurez fisiológica. Los frutos se separaron en sus tejidos y a cada uno les fue determinado en la materia seca la concentración de N, P, K, Ca, Mg, S, Fe, Cu, Mn, Zn y B. La composición nutrimental de los tejidos del fruto presentó variaciones dentro de cada cultivar. La epidermis y el embrión presentaron las mayores concentraciones de nutrimentos. La cantidad de nutrimentos removidos varió con el tejido, presentándose los valores más altos para pulpa y epidermis y los más bajos para la testa. La cantidad de nutrimentos removida por tonelada de fruto fresco fue similar en los dos cultivares de mango, con excepción del Mn cuya remoción fue mayor en los frutos de 'Haden'. Los intervalos de remoción nutrimental para 'Haden' y 'Tommy Atkins' fueron (kg t-1 fruto fresco: N (1.03-1.11, P (0.22-0.24, K (1.88-2.14, Ca (0.21-0.31, Mg (0.14-0.15, S (0.28-0.33; (g t-1 fruto fresco: Fe (3.53.8, Cu (1.0-1.1, Mn (3.2-4.8, Zn (2.0-2.8 y B (1.5-1.6.To improve the management of mango nutrition and maintain soil fertility it is necessary to know the nutrient composition of the fruit as well as the amount of nutrients removed by the crop planting . This study

  12. Influence of trace erythromycin and eryhthromycin-H2O on carbon and nutrients removal and on resistance selection in sequencing batch reactors (SBRs). (United States)

    Fan, Caian; Lee, Patrick K H; Ng, Wun Jern; Alvarez-Cohen, Lisa; Brodie, Eoin L; Andersen, Gary L; He, Jianzhong


    Three sequencing batch reactors (SBRs) were operated in parallel to study the effects of trace erythromycin (ERY) and ERY-H2O on the treatment of a synthetic wastewater. Through monitoring (1) daily effluents and (2) concentrations of nitrogen (N) and phosphorous (P) in certain batch cycles of the three reactors operated from transient to steady states, the removal of carbon, N, and P was affected negligibly by ERY (100 microg/L) or ERY-H2O (50 microg/L) when compared with the control reactor. However, through ana