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Sample records for activated sludge samples

  1. Extraction DNA from Activated Sludge-Comparing with Soil Sample

    Institute of Scientific and Technical Information of China (English)

    谢冰; 奚旦立; 陈季华

    2003-01-01

    DNA directly extraction from activated sludge and soil sample with enzyme lyses methods was investigated in this paper. DNA yield from activated sludge was 3.0 mg/g. VLSS, and 28.2-43.8 μg/g soil respectively. The resulting DNA is suitable for PCR.By studied methods, higher quality and quantity of sludge DNA could be obtained rapidly and inexpensively from large number of samples, and the PCR product obtained from this protocol was not affected by contaminated higher concentration of heavy metals.

  2. Respirometry in activated sludge

    NARCIS (Netherlands)

    Spanjers, H.

    1993-01-01

    The purpose of the study was (1) to develop a respiration meter capable of continuously measuring, using different procedures, the oxygen uptake rate of activated sludge and (2) to expand knowledge about respiration related characteristics of wastewater and activated sludge.

    A

  3. Activated Sludge Rheology

    DEFF Research Database (Denmark)

    Ratkovich, Nicolas Rios; Horn, Willi; Helmus, Frank

    2013-01-01

    Rheological behaviour is an important fluid property that severely impacts its flow behaviour and many aspects related to this. In the case of activated sludge, the apparent viscosity has an influence on e.g. pumping, hydrodynamics, mass transfer rates, sludge-water separation (settling and filtr...

  4. Biodegradation of chlorpyrifos by Klebsiella sp. isolated from an activated sludge sample of waste water treatment plant in Damascus.

    Science.gov (United States)

    Ghanem, I; Orfi, M; Shamma, M

    2007-01-01

    A chlorpyrifos (CPY)-degrading bacterial strain was isolated from an activated sludge sample collected from the Damascus Wastewater Treatment Plant, Syria. The isolation of Klebsiella sp. was facilitated by the addition of CPY at a rate of 3.84 g/L of sludge weekly (selection pressure). Identification of Klebsiella sp. was done using major staining and biochemical differentiation tests (Gram stain, cytochrome oxidase and some relevant saccharide fermentation tests using biochemical assays). Klebsiella sp. was maintained by culturing in a poor medium consisting of mineral salts and CPY as the sole carbon source. When 3 activated sludge samples were incubated in the presence of CPY (13.9 g/L sludge), 46% of added CPY were degraded within 4 d. By comparison, within 4 d the isolated Klebsiella sp. was found to break down 92% of CPY when co-incubated in a poor mineral medium in which CPY was the sole carbon source (13.9 g/L poor medium). Isolated Klebsiella sp. was able to tolerate up to 17.3 g of CPY in the poor medium.

  5. Activated sludge model No. 3

    DEFF Research Database (Denmark)

    Gujer, W.; Henze, M.; Mino, T.

    1999-01-01

    The Activated Sludge Model No. 3 (ASM3) can predict oxygen consumption, sludge production, nitrification and denitrification of activated sludge systems. It relates to the Activated Sludge Model No. 1 (ASM1) and corrects for some defects of ASM I. In addition to ASM1, ASM3 includes storage...

  6. 40 CFR 61.54 - Sludge sampling.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 8 2010-07-01 2010-07-01 false Sludge sampling. 61.54 Section 61.54... sampling. (a) As an alternative means for demonstrating compliance with § 61.52(b), an owner or operator... days prior to a sludge sampling test, so that he may at his option observe the test. (c) Sludge...

  7. Activated sludge inhibition capacity index

    Directory of Open Access Journals (Sweden)

    V. Surerus

    2014-06-01

    Full Text Available Toxic compounds in sewage or industrial wastewater may inhibit the biological activity of activated sludge impairing the treatment process. This paper evaluates the Inhibition Capacity Index (ICI for the assessment of activated sludge in the presence of toxicants. In this study, activated sludge was obtained from industrial treatment plants and was also synthetically produced. Continuous respirometric measurements were carried out in a reactor, and the oxygen uptake rate profile obtained was used to evaluate the impact of inhibiting toxicants, such as dissolved copper, phenol, sodium alkylbenzene sulfonate and amoxicillin, on activated sludge. The results indicate that ICI is an efficient tool to quantify the intoxication capacity. The activated sludge from the pharmaceutical industry showed higher resistance than the sludge from other sources, since toxicants are widely discharged in the biological treatment system. The ICI range was from 58 to 81% when compared to the synthetic effluent with no toxic substances.

  8. Revised sampling campaigns to provide sludge for treatment process testing

    Energy Technology Data Exchange (ETDEWEB)

    PETERSEN, C.A.

    1999-02-18

    The purpose of this document is to review the impact to the sludge sampling campaigns planned for FY 1999 given the recent decision to delete any further sludge sampling in the K West Basin. Requirements for Sludge sample material for Sludge treatment process testing are reviewed. Options are discussed for obtaining the volume sample material required and an optimized plan for obtaining this sludge is summarized.

  9. Lipase and protease extraction from activated sludge

    DEFF Research Database (Denmark)

    Gessesse, Amare; Dueholm, Thomas; Petersen, Steffen B.

    2003-01-01

    of gentle and efficient enzyme extraction methods from environmental samples is very important. In this study we present a method for the extraction of lipases and proteases from activated sludge using the non-ionic detergent Triton X-100, EDTA, and cation exchange resin (CER), alone or in combination...... for the extraction of lipases and proteases from activated sludge. The sludge was continuously stirred in the presence of either buffer alone or in the presence of detergent and/or chelating agents. In all cases, a marked reduction in floc size was observed upon continuous stirring. However, no lipase activity...... and negligible protease activity was extracted in the presence of buffer alone, indicating that enzyme extraction was not due to shear force alone. The highest lipase activity was extracted using 0.1% Triton X-100 above which the activity was gradually decreasing. For proteases, the highest activity was obtained...

  10. Strategies for selecting optimal sampling and work-up procedures for analysing alkylphenol polyethoxylates in effluents from non-activated sludge biofilm reactors.

    Science.gov (United States)

    Stenholm, Ake; Holmström, Sara; Hjärthag, Sandra; Lind, Ola

    2012-01-01

    Trace-level analysis of alkylphenol polyethoxylates (APEOs) in wastewater containing sludge requires the prior removal of contaminants and preconcentration. In this study, the effects on optimal work-up procedures of the types of alkylphenols present, their degree of ethoxylation, the biofilm wastewater treatment and the sample matrix were investigated for these purposes. The sampling spot for APEO-containing specimens from an industrial wastewater treatment plant was optimized, including a box that surrounded the tubing outlet carrying the wastewater, to prevent sedimented sludge contaminating the collected samples. Following these changes, the sampling precision (in terms of dry matter content) at a point just under the tubing leading from the biofilm reactors was 0.7% RSD. The findings were applied to develop a work-up procedure for use prior to a high-performance liquid chromatography-fluorescence detection analysis method capable of quantifying nonylphenol polyethoxylates (NPEOs) and poorly investigated dinonylphenol polyethoxylates (DNPEOs) at low microg L(-1) concentrations in effluents from non-activated sludge biofilm reactors. The selected multi-step work-up procedure includes lyophilization and pressurized fluid extraction (PFE) followed by strong ion exchange solid phase extraction (SPE). The yields of the combined procedure, according to tests with NP10EO-spiked effluent from a wastewater treatment plant, were in the 62-78% range.

  11. Activated Sludge Ozonation to Reduce Sludge Production in MBR

    Institute of Scientific and Technical Information of China (English)

    HE Sheng-bing; XUE Gang; WANG Bao-zhen

    2005-01-01

    The total experimental period was divided into two stages.At the first stage, a series of batch studies were carried out to get an understanding of the effect of ozonation on sludge properties. At the following stages, three MBRs with different amounts of activated sludge to be ozonated were run in parallel for a long period to evaluate the influence of sludge ozonation on sludge yield and permeate quality.Through batch study, it was found that ozone could disrupt the cell walls and caused the release of plasm from the cells,then the amounts of soluble organics in the solution increased with ozonation time. With the rise of soluble organics, the amount of soluble organics to be mineralized increased as well, which wonld reduce the soluble organics content. For the counteraction between these two aspects, a pseudo-balance could be achieved, and soluble organics would vary in a limited range. Sludge ozonation also increased the contents of nitrogen and phosphorus in the solution. In addition, ozonation was effective in improving sludge settling property. On the basis of batch study, a suitable ozone dosage of 0.16 kgO3/kgMLSS wasdetermined. Three systems were run in parallel for a total period of 39 days, it was demonstrated that a part of activated sludge ozonation could reduce sludge production significantly, and biological performance of mineralization and nitrification would not be inhibited due to sludge ozonation. Experimental results proved that the combination of ozonation unit with MBR unit could achieve an excellent quality of permeate as well as a small quantity of sludge production, and economic analysis indicated that an additional ozonation operating cost for treatment of both wastewater and sludge was only 0.096Yuan (US $0.011,5)/m3 wastewater.

  12. Bioflocculation of mesophilic and thermophilic activated sludge

    NARCIS (Netherlands)

    Vogelaar, J.C.T.; Keizer, de A.; Spijker, S.; Lettinga, G.

    2005-01-01

    Thermophilic activated sludge treatment is often hampered by a turbid effluent. Reasons for this phenomenon are so far unknown. Here, the hypothesis of the temperature dependency of the hydrophobic interaction as a possible cause for diminished thermophilic activated sludge bioflocculation was teste

  13. Transient Response of Aerobic and Anoxic Activated Sludge Activities to Sudden Substrate Concentration Changes

    DEFF Research Database (Denmark)

    Sin, G.; Vanrolleghem, P.A.; Gernaey, Krist

    2004-01-01

    process. That transient phenomenon exhibits itself immediately upon addition of a substrate source to an endogenously respiring activated sludge sample and it usually takes a few minutes until the activated sludge reaches its maximum possible rate under given environmental conditions. This discrepancy......The state-of-the-art understanding of activated sludge processes as summarized in activated sludge models (ASMs) predicts an instantaneous increase in the biomass activity (which is measured, e.g., by the corresponding respiration rate OUR, NUR, etc.) under sudden substrate concentration changes...... with fast-alternating process conditions, although such studies are beyond the scope of this report. (C) 2004 Wiley Periodicals, Inc....

  14. INFLUENCE OF SELECTED PHARMACEUTICALS ON ACTIVATED SLUDGE DEHYDROGENASE ACTIVITY

    Directory of Open Access Journals (Sweden)

    Agnieszka Tomska

    2016-06-01

    The aim of this work was to evaluate the effect of selected antibiotics - sulfanilamide and erythromycin on activated sludge dehydrogenase activity with use of trifenyltetrazolinum chloride (TTC test. Dehydrogenases activity is an indicator of biochemical activity of microorganisms present in activated sludge or the ability to degrade organic compounds in waste water. TTC test is particularly useful for the regularity of the course of treatment, in which the presence of inhibitors of biochemical reactions and toxic compounds are present. It was observed that the dehydrogenase activity decreases with the increase of a antibiotics concentration. The lowest value of the dehydrogenase activity equal to 32.4 μmol TF / gMLSS obtained at sulfanilamide concentration 150mg / l. For this sample, an inhibition of dehydrogenase activity was 31%.

  15. Physiological adaptation of growth kinetics in activated sludge.

    Science.gov (United States)

    Friedrich, M; Takács, I; Tränckner, J

    2015-11-15

    Physiological adaptation as it occurs in bacterial cells at variable environmental conditions influences characteristic properties of growth kinetics significantly. However, physiological adaptation to growth related parameters in activated sludge modelling is not yet recognised. Consequently these parameters are regarded to be constant. To investigate physiological adaptation in activated sludge the endogenous respiration in an aerobic degradation batch experiment and simultaneous to that the maximum possible respiration in an aerobic growth batch experiment was measured. The activated sludge samples were taken from full scale wastewater treatment plants with different sludge retention times (SRTs). It could be shown that the low SRT sludge adapts by growth optimisation (high maximum growth rate and high decay rate) to its particular environment where a high SRT sludge adapts by survival optimization (low maximum growth rate and low decay rate). Thereby, both the maximum specific growth rate and the decay rate vary in the same pattern and are strongly correlated to each other. To describe the physiological state of mixed cultures like activated sludge quantitatively a physiological state factor (PSF) is proposed as the ratio of the maximum specific growth rate and the decay rate. The PSF can be expressed as an exponential function with respect to the SRT.

  16. Lipase and protease extraction from activated sludge

    DEFF Research Database (Denmark)

    Gessesse, Amare; Dueholm, Thomas; Petersen, Steffen B.

    2003-01-01

    In the process of wastewater treatment hydrolysis of polymeric substances is the first and rate-limiting step. A closer study of the enzymes catalysing these reactions is essential for a better understanding of the microbial activity in the wastewater treatment process. Therefore, development...... of gentle and efficient enzyme extraction methods from environmental samples is very important. In this study we present a method for the extraction of lipases and proteases from activated sludge using the non-ionic detergent Triton X-100, EDTA, and cation exchange resin (CER), alone or in combination...... and negligible protease activity was extracted in the presence of buffer alone, indicating that enzyme extraction was not due to shear force alone. The highest lipase activity was extracted using 0.1% Triton X-100 above which the activity was gradually decreasing. For proteases, the highest activity was obtained...

  17. The role and control of sludge age in biological nutrient removal activated sludge systems.

    Science.gov (United States)

    Ekama, G A

    2010-01-01

    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.

  18. Excess sludge reduction in activated sludge processes by integrating ultrasound treatment

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Elvira, S.; Fdz-Polanco, M.; Plaza, F. I.; Garralon, G.; Fdz-Polanco, F.

    2009-07-01

    Biological sludge produced in the activated sludge process can be minimised modifying the water line, the sludge line or the final disposal strategy. Selecting the water line the general idea is to reduce the sludge producing the yield coefficient by means of the called lysis cryptic growth process. The main techniques referenced in literature are onization, chlorination and chemical and heat treatment. Ultrasounds are widely used to increase anaerobic biodegradability but are not reported as system to control excess sludge production. (Author)

  19. Comparison of membrane fouling during short-term filtration of aerobic granular sludge and activated sludge

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Aerobic granular sludge was cultivated adopting internal-circulate sequencing batch airlift reactor. The contradistinctive experiment about short-term membrane fouling between aerobic granular sludge system and activated sludge system were investigated. The membrane foulants was also characterized by Fourier Transform Infrared (FTIR) spectroscopy technique. The results showed that the aerobic granular sludge had excellent denitrification ability; the removal efficiency of TN could reach 90%. The aerobic granular sludge could alleviate membrane fouling effectively. The steady membrane flux of aerobic granular sludge was twice as much as that of activated sludge system. In addition, it was found that the aerobic granular sludge could result in severe membrane pore-blocking, however, the activated sludge could cause severe cake fouling. The major components of the foulants were identified as comprising of proteins and polysaccharide materials.

  20. 241-Z-361 Sludge Characterization Sampling and Analysis Plan

    Energy Technology Data Exchange (ETDEWEB)

    BANNING, D.L.

    1999-08-05

    This sampling and analysis plan (SAP) identifies the type, quantity, and quality of data needed to support characterization of the sludge that remains in Tank 241-2-361. The procedures described in this SAP are based on the results of the 241-2-361 Sludge Characterization Data Quality Objectives (DQO) (BWHC 1999) process for the tank. The primary objectives of this project are to evaluate the contents of Tank 241-2-361 in order to resolve safety and safeguards issues and to assess alternatives for sludge removal and disposal.

  1. 241-Z-361 Sludge Characterization Sampling and Analysis Plan

    Energy Technology Data Exchange (ETDEWEB)

    BANNING, D.L.

    1999-07-29

    This sampling and analysis plan (SAP) identifies the type, quantity, and quality of data needed to support characterization of the sludge that remains in Tank 241-2-361. The procedures described in this SAP are based on the results of the 241-2-361 Sludge Characterization Data Quality Objectives (DQO) (BWHC 1999) process for the tank. The primary objectives of this project are to evaluate the contents of Tank 241-2-361 in order to resolve safety and safeguards issues and to assess alternatives for sludge removal and disposal.

  2. Evaluation-of soil enzyme activities as soil quality indicators in sludge-amended soils.

    Science.gov (United States)

    Dindar, Efsun; Şağban, Fatma Olcay Topaç; Başkaya, Hüseyin Savaş

    2015-07-01

    Soil enzymatic activities are commonly used as biomarkers of soil quality. Several organic and inorganic compounds found in municipal wastewater sludges can possibly be used as fertilizers. Monitoring and evaluating the quality of sludge amended soils with enzyme activities accepted as a beneficial practice with respect to sustainable soil management. In the present study, variation of some enzyme activities (Alkaline phosphatase, dehydrogenase, urease and beta-glucosidase activities) in soils amended with municipal wastewater sludge at different application rates (50, 100 and 200 t ha(-1) dry sludge) was evaluated. Air dried sludge samples were applied to soil pots and sludge-soil mixtures were incubated during a period of three months at 28 degrees C. The results of the study showed that municipal wastewater sludge amendment apparently increased urease, dehydrogenase, alkaline phosphatase and P-glucosidase activities in soil by 48-70%, 14-47%, 33-66% and 9-14%, respectively. The maximum activity was generally observed in sludge amended soil with dose of 200 t ha(-1). Urease activity appeared to be a better indicator of soil enhancement with wastewater sludge, as its activity was more strongly increased by sludge amendment. Accordingly, urease activity is suggested to be soil quality indicator best suited for measuring existing conditions and potential changes in sludge-amended soil.

  3. Data quality objectives for K West canister sludge sampling

    Energy Technology Data Exchange (ETDEWEB)

    Makenas, B.J., Westinghouse Hanford

    1996-12-11

    Data Quality Objectives have been developed for a limited campaign of sampling K Basin canister sludge. Specifically, samples will be taken from the sealed K West Basin fuel canisters. Characterization of the sludge in these canisters will address the needs of fuel retrieval which are to collect and transport sludge which is currently in the canisters. Data will be gathered on physical properties (such as viscosity, particle size, density, etc.) as well as on chemical and radionuclide constituents and radiation levels of sludge. The primary emphasis will be on determining radionuclide concentrations to be deposited on Ion Exchange Modules (IXMS) during canister opening and fuel retrieval. The data will also be useful in determining whether K West Basin sludge meets the waste acceptance criteria for Hanford waste tanks as a backup disposal concept and these data will also supply information on the properties of sludge material which will1403 accompany fuel elements in the Multi-Canister Overpacks (MCOS) as envisioned in the Integrated Process Strategy (IPS).

  4. Filterability of membrane bioreactor (MBR) sludge: impacts of polyelectrolytes and mixing with conventional activated sludge.

    Science.gov (United States)

    Yigit, Nevzat O; Civelekoglu, Gokhan; Cinar, Ozer; Kitis, Mehmet

    2010-01-01

    The main objective of this work was to investigate the filterability of MBR sludge and its mixture with conventional activated sludge (CAS). In addition, the impacts of type and dose of various polyelectrolytes, filter type and sludge properties on the filterability of both MBR and Mixed sludges were determined. Specific cake resistance (SCR) measured by the Buchner funnel filtration test apparatus and the solids content of the resulting sludge cake were used to assess the dewaterability of tested sludges. The type of filter paper used in Buchner tests affected the results of filterability for MBR, CAS and Mixed sludges. SCR values and optimum polyelectrolyte doses increased with increasing MLSS concentrations in the MBR, which suggested that increase in MLSS concentrations accompanied by increases in EPS and SMP concentrations and a shift toward smaller particles caused poorer dewaterability of the MBR sludge. The significant differences observed among the filterability of CAS and MBR sludges suggested that MLSS alone is not a good predictor of sludge dewaterability. Combining CAS and MBR sludges at different proportions generally improved their dewaterability. Combining MBR sludges having typically high MLSS and EPS concentrations with CAS having much lower MLSS concentrations may be an option for full-scale treatment plants experiencing sludge dewaterability problems. Better filterability and higher cake dry solids were achieved with cationic polyelectrolytes compared to anionic and non-ionic ones for all sludge types tested.

  5. Enzyme Activities in Waste Water and Activated Sludge

    DEFF Research Database (Denmark)

    Nybroe, Ole; Jørgensen, Per Elberg; Henze, Mogens

    1992-01-01

    The purpose of the present study was to evaluate the potential of selected enzyme activity assays to determine microbial abundance and heterotrophic activity in waste water and activated sludge. In waste water, esterase and dehydrogenase activities were found to correlate with microbial abundance...... measured as colony forming units of heterotrophic bacteria. A panel of four enzyme activity assays, α-glucosidase, alanine-aminopeptidase, esterase and dehydrogenase were used to characterize activated sludge and anaerobic hydrolysis sludge from a pilot scale plant. The enzymatic activity profiles were...... distinctly different, suggesting that microbial populations were different, or had different physiological properties, in the two types of sludge. Enzyme activity profiles in activated sludge from four full-scale plants seemed to be highly influenced by the composition of the inlet. Addition of hydrolysed...

  6. Extracellular polymers of ozonized waste activated sludge.

    Science.gov (United States)

    Liu, J C; Lee, C H; Lai, J Y; Wang, K C; Hsu, Y C; Chang, B V

    2001-01-01

    Effect of ozonation on characteristics of waste activated sludge was investigated in the current study. Concentrations of cell-bound extracellular polymers (washed ECPs) did not change much upon ozonation, whereas the sum of cell-bound and soluble extracellular polymers (unwashed ECPs) increased with increasing ozone dose. Washed ECPs in original sludge as divided by molecular weight distribution was 39% 10,000 Da (high MW). It was observed that the low-MW fraction decreased, and the high-MW fraction increased in ozonized sludge. The unwashed ECPs were characterized as 44% in low MW, 30% in medium MW, and 26% in high MW. Both low-MW and medium-MW fractions of unwashed ECPs decreased while high-MW fraction increased in ozonized sludge. The dewaterability of ozonized sludge, assessed by capillary suction time (CST) and specific resistance to filtration (SRF), deteriorated with ozone dose. The optimal dose of cationic polyelectrolyte increased with increasing ozone dose. The production rate and the accumulated amount of methane gas of ozonized sludge were also higher.

  7. Polyhydroxyalkanoate production potential of heterotrophic bacteria in activated sludge.

    Science.gov (United States)

    Inoue, Daisuke; Suzuki, Yuta; Uchida, Takahiro; Morohoshi, Jota; Sei, Kazunari

    2016-01-01

    This study was conducted to evaluate the polyhydroxyalkanoate (PHA) production potential of cultivable heterotrophic bacteria in activated sludge by genotypic and phenotypic characterizations. A total of 114 bacterial strains were isolated from four activated sludge samples taken from a lab-scale sequencing batch reactor and three wastewater treatment processes of two municipal wastewater treatment plants. PCR detection of the phaC genes encoding class I and II PHA synthase revealed that 15% of the total isolates possessed phaC genes, all of which had the closest similarities to known phaC genes of α- and β-Proteobacteria and Actinobacteria. PHA production experiments under aerobic and nitrogen-limited conditions showed that 68% of the total isolates were capable of producing PHA from at least one of the six substrates used (acetate, propionate, lactate, butyrate, glucose and glycerol). Genotypic and phenotypic characterizations revealed that 75% of the activated sludge bacteria had PHA production potential. Our results also indicated that short-chain fatty acids would be the preferable substrates for PHA production by activated sludge bacteria, and that there might be a variety of unidentified phaC genes in activated sludge.

  8. Sampling and analysis plan for sludge located on the floor and in the pits of the 105-K basins

    Energy Technology Data Exchange (ETDEWEB)

    BAKER, R.B.

    1998-11-20

    This Sampling and Analysis Plan (SAP) provides direction for the sampling of the sludge found on the floor and in the remote pits of the 105-K Basins to provide: (1) basic data for the sludges that have not been characterized to-date and (2) representative Sludge material for process tests to be made by the SNF Project/K Basins sludge treatment process subproject. The sampling equipment developed will remove representative samples of the radioactive sludge from underwater at the K Basins, depositing them in shielded containers for transport to the Hanford Site laboratories. Included in the present document is the basic background logic for selection of the samples to meet the requirements established in the Data Quality Objectives (DQO), HNF-2033, for this sampling activity. The present document also includes the laboratory analyses, methods, procedures, and reporting that will be required to meet the DQO.

  9. Who is actively denitrifying in activated sludge?

    DEFF Research Database (Denmark)

    Hansen, Aviaja Anna; Nielsen, Jeppe Lund

    transcripts came from Gammaproteobacteria. A clear taxonomic discrepancy was observed between the nirS and nirK expressing bacteria, which primarily belonged to Beta- and Alphaproteobacteria, respectively. The nosZ gene was expressed by both taxonomic groups and it was therefore surprising that the highest......-scale wastewater treatment plant the transcripts (mRNA) of the nirS, nirK and nosZ denitrification genes expressed under acetate or amino acid consumption were amplified, sequenced and identified. This revealed that the majority of the denitrifiers belonged to Alpha- and Betaproteobacteria, while only few...... genetic diversity was observed from the nirS transcripts and not the nosZ transcripts. Likewise, denitrifying cultures obtained from the activated sludge affiliated with the same Alpha- and Betaproteobacteria as detected with the denitrification genes, except one culture, which affiliated...

  10. Norm in soil and sludge samples in Dukhan oil Field, Qatar state

    Energy Technology Data Exchange (ETDEWEB)

    Al-Kinani, A.T.; Hushari, M.; Al-Sulaiti, Huda; Alsadig, I.A., E-mail: mmhushari@moe.gov.qa [Radiation and Chemical Protection Department, Ministry of Environment, Doha (Qatar)

    2015-07-01

    The main objective of this work is to measure the activity concentrations of Naturally Occurring radioactive Materials (NORM) produced as a buy products in oil production. The analyses of NORM give available information for guidelines concerning radiation protection. Recently NORM subjected to restricted regulation issued by high legal authority at Qatar state. Twenty five samples of soil from Dukhan onshore oil field and 10 sludge samples collected from 2 offshore fields at Qatar state. High resolution low-level gamma-ray spectrometry used to measure gamma emitters of NORM. The activity concentrations of natural radionuclide in 22 samples from Dukhan oil field, were with average worldwide values . Only three soil samples have high activity concentration of Ra-226 which is more than 185 Bq/kg the exempted level for NORM in the Quatrain regulation. The natural radionuclide activity concentrations of 10 sludge samples from offshore oil fields was greater than 1100Bq/kg the exempted values of NORM set by Quatrain regulation so the sludge need special treatments. The average hazards indices (H{sub ex} , D , and Ra{sub eq}), for the 22 samples were below the word permissible values .This means that the human exposure to such material not impose any radiation risk. The average hazards indices (H{sub ex} , D , and Ra{sub eq}), for 3 soil samples and sludge samples are higher than the published maximal permissible. Thus human exposure to such material impose radiation risk. (author)

  11. Metaproteomics provides functional insight into activated sludge wastewater treatment.

    Directory of Open Access Journals (Sweden)

    Paul Wilmes

    Full Text Available BACKGROUND: Through identification of highly expressed proteins from a mixed culture activated sludge system this study provides functional evidence of microbial transformations important for enhanced biological phosphorus removal (EBPR. METHODOLOGY/PRINCIPAL FINDINGS: A laboratory-scale sequencing batch reactor was successfully operated for different levels of EBPR, removing around 25, 40 and 55 mg/l P. The microbial communities were dominated by the uncultured polyphosphate-accumulating organism "Candidatus Accumulibacter phosphatis". When EBPR failed, the sludge was dominated by tetrad-forming alpha-Proteobacteria. Representative and reproducible 2D gel protein separations were obtained for all sludge samples. 638 protein spots were matched across gels generated from the phosphate removing sludges. 111 of these were excised and 46 proteins were identified using recently available sludge metagenomic sequences. Many of these closely match proteins from "Candidatus Accumulibacter phosphatis" and could be directly linked to the EBPR process. They included enzymes involved in energy generation, polyhydroxyalkanoate synthesis, glycolysis, gluconeogenesis, glycogen synthesis, glyoxylate/TCA cycle, fatty acid beta oxidation, fatty acid synthesis and phosphate transport. Several proteins involved in cellular stress response were detected. CONCLUSIONS/SIGNIFICANCE: Importantly, this study provides direct evidence linking the metabolic activities of "Accumulibacter" to the chemical transformations observed in EBPR. Finally, the results are discussed in relation to current EBPR metabolic models.

  12. Metaproteomics Provides Functional Insight into Activated Sludge Wastewater Treatment

    Science.gov (United States)

    Wilmes, Paul; Wexler, Margaret; Bond, Philip L.

    2008-01-01

    Background Through identification of highly expressed proteins from a mixed culture activated sludge system this study provides functional evidence of microbial transformations important for enhanced biological phosphorus removal (EBPR). Methodology/Principal Findings A laboratory-scale sequencing batch reactor was successfully operated for different levels of EBPR, removing around 25, 40 and 55 mg/l P. The microbial communities were dominated by the uncultured polyphosphate-accumulating organism “Candidatus Accumulibacter phosphatis”. When EBPR failed, the sludge was dominated by tetrad-forming α-Proteobacteria. Representative and reproducible 2D gel protein separations were obtained for all sludge samples. 638 protein spots were matched across gels generated from the phosphate removing sludges. 111 of these were excised and 46 proteins were identified using recently available sludge metagenomic sequences. Many of these closely match proteins from “Candidatus Accumulibacter phosphatis” and could be directly linked to the EBPR process. They included enzymes involved in energy generation, polyhydroxyalkanoate synthesis, glycolysis, gluconeogenesis, glycogen synthesis, glyoxylate/TCA cycle, fatty acid β oxidation, fatty acid synthesis and phosphate transport. Several proteins involved in cellular stress response were detected. Conclusions/Significance Importantly, this study provides direct evidence linking the metabolic activities of “Accumulibacter” to the chemical transformations observed in EBPR. Finally, the results are discussed in relation to current EBPR metabolic models. PMID:18392150

  13. The role of lipids in activated sludge floc formation

    Directory of Open Access Journals (Sweden)

    Anna Liza Kretzschmar

    2015-03-01

    Full Text Available Activated sludge is widely used to treat municipal and industrial wastewater globally and the formation of activated sludge flocculates (flocs underpins the ability to separate sludge from treated water. Despite the importance of activated sludge flocs to human civilization there have been precious few attempts to rationally design fit for purpose flocs using a bottom-up approach based on a solid scientific foundation. Recently we have been developing experimental models for activated sludge floc formation based on the colonization and consumption of particulate organic matter (chitin and cellulose. In this study we lay the foundation for investigation of activated sludge floc formation based on biofilm formation around spheres of the lipid glycerol trioleate (GT that form spontaneously when GT is introduced into activated sludge incubations. Sludge biomass was observed to associate tightly with the lipid spheres. An increase in extracellular lipase activity was associated with a decrease in size of the colonized lipid spheres over a 25 day incubation. Bacterial community composition shifted from predominantly Betaproteobacteria to Alphaproteobacteria in GT treated sludge. Four activated sludge bacteria were isolated from lipid spheres and two of them were shown to produce AHL like quorum sensing signal activity, suggesting quorum sensing may play a role in lipid spheres colonization and biodegradation in activated sludge. The development of this experimental model of activated sludge floc formation lays the foundation for rational production of flocs for wastewater treatment using lipids as floc nuclei and further development of the flocculate life-cycle concept.

  14. Upflow Sludge Blanket Filtration (USBF: An Innovative Technology in Activated Sludge Process

    Directory of Open Access Journals (Sweden)

    R Saeedi

    2010-06-01

    Full Text Available Background: A new biological domestic wastewater treatment process, which has been presented these days in activated sludge modification, is Upflow Sludge Blanket Filtration (USBF. This process is aerobic and acts by using a sludge blanket in the separator of sedimentation tank. All biological flocs and suspended solids, which are presented in the aeration basin, pas through this blanket. The performance of a single stage USBF process for treatment of domestic wastewater was studied in laboratory scale.Methods: The pilot of USBF has been made from fiberglass and the main electromechanical equipments consisted of an air com­pressor, a mixing device and two pumps for sludge return and wastewater injection. The wastewater samples used for the experiments were prepared synthetically to have qualitative characteristics similar to a typical domestic wastewater (COD= 277 mg/l, BOD5= 250 mg/l and TSS= 1 mg/l.Results: On the average, the treatment system was capable to remove 82.2% of the BOD5 and 85.7% of COD in 6 h hydraulic re­tention time (HRT. At 2 h HRT BOD and COD removal efficiencies dramatically reduced to 50% and 46.5%, respectively.Conclusion: Even by increasing the concentrations of pollutants to as high as 50%, the removal rates of all pollutants were re­mained similar to the HRT of 6 h.

  15. Fate of linear alkylbenzene sulfonate (LAS) in activated sludge plants.

    Science.gov (United States)

    Temmink, H; Klapwijk, Bram

    2004-02-01

    Monitoring data were collected in a pilot-scale municipal activated sludge plant to assess the fate of the C12-homologue of linear alkyl benzene sulfonate (LAS-C12). The pilot-plant was operated at influent LAS-C12 concentrations between 2 and 12 mg l(-1) and at sludge retention times of 10 and 27 days. Effluent and waste sludge concentrations varied between 5 and 10 microg l(-1) and between 37 and 69 microg g(-1) VSS, respectively. In the sludge samples only 2-8% was present as dissolved LAS-C12, whereas the remaining 92-98% was found to be adsorbed to the sludge. In spite of this high degree of sorption, more than 99% of the LAS-C12 load was removed by biodegradation, showing that not only the soluble fraction but also the adsorbed fraction of LAS-C12 is readily available for biodegradation. Sorption and biodegradation of LAS-C12 were also investigated separately. Sorption was an extremely fast and reversible process and could be described by a linear isotherm with a partition coefficient of 3.2 l g(-1) volatile suspended solids. From the results of biodegradation kinetic tests it was concluded that primary biodegradation of LAS-C12 cannot be described by a (growth) Monod model, but a secondary utilisation model should be used instead. The apparent affinity of the sludge to biodegrade LAS-C12 increased when the sludge was loaded with higher influent concentrations of LAS-C12.

  16. Thermal activation of an industrial sludge for a possible valorization

    Directory of Open Access Journals (Sweden)

    Lamrani Sanae

    2014-04-01

    Full Text Available This work fits within the framework of sustainable management of sludge generated from wastewater treatment in industrial network. The studied sludge comes from an industry manufacturing sanitary ware products.Physico-chemical and mineralogical characterization was performed to give an identity card to the sludge. We noted the absence of metal pollution.The industrial sludge has been subjected to thermal activation at various temperatures (650°C to 850°C. The pozzolanic activity was evaluated by physico- chemical and mechanical methods [1]. Pozzolanicity measurement was carried out based on Chapelle test and conductivity revealed the existence of pozzolanic properties of the calcined samples. The best pozzolanic reactivity was obtained for the sample calcined at 800°C. We noticed a decrease in the reactivity of the sample calcined at 850°C. In addition, analysis by means of X-ray diffraction and Fourier transform infrared spectroscopy showed that sludge recrystallization begins at a temperature of 850°C. Pozzolanicity index of the thermally treated samples was determined by measuring the mechanical resistance of mortar specimens previously kept in a saturated lime solution for 28 days (ASTM C618 [2]. The best pozzolanic activity index was obtained for the sample calcined at 800°C (109.1%.This work is a contribution to the research for new supplying sources of raw materials and additives in the field of construction. It presents a proposition of a promising solution for the valorization of waste material as an additive instead of being discharged into open air dumps causing a major environmental problem.

  17. Characterization and distribution of esterase activity in activated sludge

    NARCIS (Netherlands)

    Boczar, BA; Forney, LJ; Begley, WM; Larson, RJ; Federle, TW

    2001-01-01

    The location and activity of esterase enzymes in activated Sludge from three Municipal wastewater treatment plants were characterized using model Substrate, and denaturing and nondenaturing polyacrylamide gel electrophoresis (PAGE) Of particulate, freeze thaw (primarily periplasmic enzymes and those

  18. Partial ozonation of activated sludge to reduce excess sludge, improve denitrification and control scumming and bulking

    Energy Technology Data Exchange (ETDEWEB)

    Boehler, Marc; Siegrist, Hansruedi

    2003-07-01

    Disposal of sewage sludge is forbidden and agricultural use of stabilized sludge will be banned in 2005 in Switzerland. The sludge has to be dewatered, dried, Incinerated and the ashes disposed in landfills. These processes are cost intensive and lead also to the loss of valuable phosphate resources incorporated in the sludge ash. The implementation of processes that could reduce excess sludge production and recycle phosphate is therefore recommended. Partial ozonation of the return sludge of an activated sludge system reduces significantly excess sludge production, improves settling properties of the sludge and reduces bulking and scumming. The solubilized COD will also improve denitrification if the treated sludge is recycled to the anoxic zone. But ozonation will partly inhibit and kill nitrifiers and might therefore lead to a decrease of the effective solid retention time of the nitrifier, which reduces the safety of the nitrification. This paper discusses the effect of ozonation on sludge reduction, the operation stability of nitrification, improvement of denitrification and gives also an energy and cost evaluation. (author)

  19. Filtration and Leach Testing for PUREX Cladding Sludge and REDOX Cladding Sludge Actual Waste Sample Composites

    Energy Technology Data Exchange (ETDEWEB)

    Shimskey, Rick W.; Billing, Justin M.; Buck, Edgar C.; Casella, Amanda J.; Crum, Jarrod V.; Daniel, Richard C.; Draper, Kathryn E.; Edwards, Matthew K.; Hallen, Richard T.; Kozelisky, Anne E.; MacFarlan, Paul J.; Peterson, Reid A.; Swoboda, Robert G.

    2009-03-02

    A testing program evaluating actual tank waste was developed in response to Task 4 from the M-12 External Flowsheet Review Team (EFRT) issue response plan (Barnes and Voke 2006). The test program was subdivided into logical increments. The bulk water-insoluble solid wastes that are anticipated to be delivered to the Hanford Waste Treatment and Immobilization Plant (WTP) were identified according to type such that the actual waste testing could be targeted to the relevant categories. Under test plan TP RPP WTP 467 (Fiskum et al. 2007), eight broad waste groupings were defined. Samples available from the 222S archive were identified and obtained for testing. Under this test plan, a waste testing program was implemented that included: • Homogenizing the archive samples by group as defined in the test plan. • Characterizing the homogenized sample groups. • Performing parametric leaching testing on each group for compounds of interest. • Performing bench-top filtration/leaching tests in the hot cell for each group to simulate filtration and leaching activities if they occurred in the UFP2 vessel of the WTP Pretreatment Facility. This report focuses on a filtration/leaching test performed using two of the eight waste composite samples. The sample groups examined in this report were the plutonium-uranium extraction (PUREX) cladding waste sludge (Group 3, or CWP) and reduction-oxidation (REDOX) cladding waste sludge (Group 4, or CWR). Both the Group 3 and 4 waste composites were anticipated to be high in gibbsite, thus requiring caustic leaching. WTP RPT 167 (Snow et al. 2008) describes the homogenization, characterization, and parametric leaching activities before benchtop filtration/leaching testing of these two waste groups. Characterization and initial parametric data in that report were used to plan a single filtration/leaching test using a blend of both wastes. The test focused on filtration testing of the waste and caustic leaching for aluminum, in the form

  20. Characterization Of The As-Received Sludge Batch 9 Qualification Sample (Htf-51-15-81)

    Energy Technology Data Exchange (ETDEWEB)

    Pareizs, J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-09-30

    Savannah River National Laboratory (SRNL) personnel have been requested to qualify the next sludge batch (Sludge Batch 9 – SB9) for processing at the Defense Waste Processing Facility (DWPF). To accomplish this task, Savannah River Remediation (SRR) has sent SRNL a 3-L slurried sample of Tank 51H (HTF-51-15-81) to be characterized, washed, and then used in a lab-scale demonstration of the DWPF flowsheet (potentially after combining with Tank 40H sludge). This report documents the first steps of the qualification process – characterization of the as-received Tank 51H qualification sample. These results will be used to support a reprojection of SB9 by SRR from which final Tank 51H washing, frit development, and Chemical Processing Cell (CPC) activities will be based.

  1. High-rate anaerobic co-digestion of kraft mill fibre sludge and activated sludge by CSTRs with sludge recirculation.

    Science.gov (United States)

    Ekstrand, Eva-Maria; Karlsson, Marielle; Truong, Xu-Bin; Björn, Annika; Karlsson, Anna; Svensson, Bo H; Ejlertsson, Jörgen

    2016-10-01

    Kraft fibre sludge from the pulp and paper industry constitutes a new, widely available substrate for the biogas production industry, with high methane potential. In this study, anaerobic digestion of kraft fibre sludge was examined by applying continuously stirred tank reactors (CSTR) with sludge recirculation. Two lab-scale reactors (4L) were run for 800days, one on fibre sludge (R1), and the other on fibre sludge and activated sludge (R2). Additions of Mg, K and S stabilized reactor performance. Furthermore, the Ca:Mg ratio was important, and a stable process was achieved at a ratio below 16:1. Foaming was abated by short but frequent mixing. Co-digestion of fibre sludge and activated sludge resulted in more robust conditions, and high-rate operation at stable conditions was achieved at an organic loading rate of 4g volatile solids (VS)L(-1)day(-1), a hydraulic retention time of 4days and a methane production of 230±10NmL per g VS.

  2. Enhancement of sludge reduction and methane production by removing extracellular polymeric substances from waste activated sludge.

    Science.gov (United States)

    Nguyen, Minh Tuan; Mohd Yasin, Nazlina Haiza; Miyazaki, Toshiki; Maeda, Toshinari

    2014-12-01

    The management of waste activated sludge (WAS) recycling is a concern that affects the development of the future low-carbon society, particularly sludge reduction and biomass utilization. In this study, we investigated the effect of removing extracellular polymeric substances (EPS), which play important roles in the adhesion and flocculation of WAS, on increased sludge disintegration, thereby enhancing sludge reduction and methane production by anaerobic digestion. EPS removal from WAS by ethylenediaminetetraacetic acid (EDTA) significantly enhanced sludge reduction, i.e., 49 ± 5% compared with 27 ± 1% of the control at the end the digestion process. Methane production was also improved in WAS without EPS by 8881 ± 109 CH4 μmol g(-1) dry-weight of sludge. Microbial activity was determined by denaturing gradient gel electrophoresis and real-time polymerase chain reaction, which showed that the hydrolysis and acetogenesis stages were enhanced by pretreatment with 2% EDTA, with a larger methanogenic community and better methane production.

  3. Adsorption of Phthalates on Municipal Activated Sludge

    Directory of Open Access Journals (Sweden)

    Hongbo Wang

    2017-01-01

    Full Text Available Phthalates (PAEs are commonly detected in discharge of municipal wastewater treatment plants. This study investigated the removal of six typical PAEs with activated sludge and the results revealed that concentrations of aqueous PAEs decreased rapidly during the beginning 15 min and reached equilibrium within 2 hours due to the adsorption of activated sludge. The process followed first-order kinetic equation, except for dioctyl phthalate (DOP. The factors influencing the adsorption were also evaluated and it was found that higher initial concentrations of PAEs enhanced the removal but affected little the adsorption equilibrium time. The adsorption of PAEs favored lower operating temperature (the optimum temperature was approximately 25°C in this research, which could be an exothermic process. Additionally, lower aqueous pH could also benefit the adsorption.

  4. Modelling of Activated Sludge Wastewater Treatment

    OpenAIRE

    Kurtanjeka, Ž.; Deverić Meštrović, B.; Ležajić, Z.; Bevetek, A.; Čurlin; M.

    2008-01-01

    Activated sludge wastewater treatment is a highly complex physical, chemical and biological process, and variations in wastewater flow rate and its composition, combined with time-varying reactions in a mixed culture of microorganisms, make this process non-linear and unsteady. The efficiency of the process is established by measuring the quantities that indicate quality of the treated wastewater, but they can only be determined at the end of the process, which is when the water has already b...

  5. Gravity Drainage of Activated Sludge on Reed Beds

    DEFF Research Database (Denmark)

    Christensen, Morten Lykkegaard; Dominiak, Dominik Marek; Keiding, Kristian;

    Activated sludge is a by-product from waste water treatment plants, and the water content in the sludge is high (> 90%). Among several methods to remove the water, sludge drying reed beds are often used to dewater the sludge by drainage. There is, however, no well-defined criterion for design...... has therefore been developed to measure relevant quality parameters: specific cake resistance, settling velocity and cake compressibility. It has been found that activated sludge form highly compressible cake even at the low compressive pressures obtained during drainage. Numerical simulation shows...... that the compressibility has a high influence on the drainage process especially during the start-up phases where the volumetric load on the sludge bed is critical. The load has to be low in order to ensure that the drainage properties of the bed are not destroyed. The data also shows that transport of activated sludge...

  6. The effect of operational conditions on the sludge specific methanogenic activity and sludge biodegradability

    Energy Technology Data Exchange (ETDEWEB)

    Leitao, R. C.; Santaella, S. T.; Haandel, A. C. van; Zeeman, G.; Lettinga, G.

    2009-07-01

    The Specific Methanogenic Activity (SMA) and sludge biodegradability of an anaerobic sludge depends on various operational and environmental conditions imposed to the anaerobic reactor. However, the effects of hydraulic retention time (HRT), influent COD concentration (COD{sub i}nf) and sludge retention time (SRT) on those two parameters need to be elucidated. This knowledge about SMA can provide insights about the capacity of the UASB reactors to withstand organic and hydraulic shock loads, whereas the biodegradability gives information necessary for final disposal of the sludge. (Author)

  7. Global Perspectives on Activated Sludge Community Composition analyzed using 16S rRNA amplicon sequencing

    DEFF Research Database (Denmark)

    Nierychlo, Marta; Saunders, Aaron Marc; Albertsen, Mads

    communities, and in this study activated sludge sampled from 32 Wastewater Treatment Plants (WWTPs) around the world was described and compared. The top abundant bacteria in the global activated sludge ecosystem were found and the core population shared by multiple samples was investigated. The results......Activated sludge is the most commonly applied bioprocess throughout the world for wastewater treatment. Microorganisms are key to the process, yet our knowledge of their identity and function is still limited. High-througput16S rRNA amplicon sequencing can reliably characterize microbial...

  8. [Characterisation of excess sludge reduction in an anoxic + oxic-settling-anaerobic activated sludge process].

    Science.gov (United States)

    Gao, Xu; Lu, Yan-Hua; Guo, Jin-Song

    2009-05-15

    An energy balance analysis method with auto calorimeter being adopted was introduced to determine calorific values of sludge samples in influent and effluent of uncoupling tank in an anoxic (A) + oxic-settling-anaerobic (OSA) process and a reference system. The affiliation of sludge amount change and its energy content were studied, as well as potential of excess sludge reduction was evaluated through modifying performance of uncoupling tank. The characteristi s and causes of sludge reduction in OSA system were deduced according to energy and matter balance analysis. Results show that when the hydraulic retention time (HRT) of uncoupling tank are 5.56 h, 7.14 h and 9 h, the excess sludge reduction of whole A + OS Asystem are 1.236 g/d, 0.771 g/d and 0.599 g/d respectively. Energy content of sludge flows into and out of the uncoupling tank changes, the specific calorific value of sludge in effluent is inclined to be higher than that in influent with the HRT of the tank increasing: there isn't any significant difference of sludge calorific values between influent and effluent at 5.56 h, while the differences are in 99-113 J/g at 7.14 h, and 191-329 J/g at 9 h. Sludge in uncoupling tank would decay and longer HRT will result in more attenuation. It could be concluded that excess sludge reduction of A + OSA system is caused by both of sludge decay in uncoupling tank and sludge proliferation in AO reaction zone.

  9. Characterization Data Package for Containerized Sludge Samples Collected from Engineered Container SCS-CON-210

    Energy Technology Data Exchange (ETDEWEB)

    Fountain, Matthew S.; Fiskum, Sandra K.; Baldwin, David L.; Daniel, Richard C.; Bos, Stanley J.; Burns, Carolyn A.; Carlson, Clark D.; Coffey, Deborah S.; Delegard, Calvin H.; Edwards, Matthew K.; Greenwood, Lawrence R.; Neiner, Doinita; Oliver, Brian M.; Pool, Karl N.; Schmidt, Andrew J.; Shimskey, Rick W.; Sinkov, Sergey I.; Snow, Lanee A.; Soderquist, Chuck Z.; Thompson, Christopher J.; Trang-Le, Truc LT; Urie, Michael W.

    2013-09-10

    This data package contains the K Basin sludge characterization results obtained by Pacific Northwest National Laboratory during processing and analysis of four sludge core samples collected from Engineered Container SCS-CON-210 in 2010 as requested by CH2M Hill Plateau Remediation Company. Sample processing requirements, analytes of interest, detection limits, and quality control sample requirements are defined in the KBC-33786, Rev. 2. The core processing scope included reconstitution of a sludge core sample distributed among four to six 4-L polypropylene bottles into a single container. The reconstituted core sample was then mixed and subsampled to support a variety of characterization activities. Additional core sludge subsamples were combined to prepare a container composite. The container composite was fractionated by wet sieving through a 2,000 micron mesh and a 500-micron mesh sieve. Each sieve fraction was sampled to support a suite of analyses. The core composite analysis scope included density determination, radioisotope analysis, and metals analysis, including the Waste Isolation Pilot Plant Hazardous Waste Facility Permit metals (with the exception of mercury). The container composite analysis included most of the core composite analysis scope plus particle size distribution, particle density, rheology, and crystalline phase identification. A summary of the received samples, core sample reconstitution and subsampling activities, container composite preparation and subsampling activities, physical properties, and analytical results are presented. Supporting data and documentation are provided in the appendices. There were no cases of sample or data loss and all of the available samples and data are reported as required by the Quality Assurance Project Plan/Sampling and Analysis Plan.

  10. IDENTIFICATION AND ECOPHYSIOLOGY OF ACTIVE DENITRIFIERS IN ACTIVATED SLUDGE

    DEFF Research Database (Denmark)

    Hansen, Aviaja Anna; Le-Quy, Vang; Nielsen, Kåre Lehmann;

    and when external carbon sources were supplemented to the activated sludge the composition of the denitrifying communities was significantly affected. Transcriptome profiling provided detailed insight in the metabolic pathways in several of the active denitrifiers in activated sludge. In conclusion...... reactor studies. To obtain better identification of active denitrifying communities in full-scale wastewater treatment plants (WWTPs) we applied DNA-SIP with 13C-labelled substrates, and RT-PCR of expressed denitrification genes (nirS, nirK and nosZ) upon various substrate-inductions. To come around...... were determined with quantitative FISH, while their active metabolic pathways were investigated directly in activated sludge with a tag-based metatranscriptomic approach under acetate-utilizing and denitrifying conditions. The different methods revealed a majority of denitrifiers in all WWTPs belonging...

  11. Digital image processing and analysis for activated sludge wastewater treatment.

    Science.gov (United States)

    Khan, Muhammad Burhan; Lee, Xue Yong; Nisar, Humaira; Ng, Choon Aun; Yeap, Kim Ho; Malik, Aamir Saeed

    2015-01-01

    Activated sludge system is generally used in wastewater treatment plants for processing domestic influent. Conventionally the activated sludge wastewater treatment is monitored by measuring physico-chemical parameters like total suspended solids (TSSol), sludge volume index (SVI) and chemical oxygen demand (COD) etc. For the measurement, tests are conducted in the laboratory, which take many hours to give the final measurement. Digital image processing and analysis offers a better alternative not only to monitor and characterize the current state of activated sludge but also to predict the future state. The characterization by image processing and analysis is done by correlating the time evolution of parameters extracted by image analysis of floc and filaments with the physico-chemical parameters. This chapter briefly reviews the activated sludge wastewater treatment; and, procedures of image acquisition, preprocessing, segmentation and analysis in the specific context of activated sludge wastewater treatment. In the latter part additional procedures like z-stacking, image stitching are introduced for wastewater image preprocessing, which are not previously used in the context of activated sludge. Different preprocessing and segmentation techniques are proposed, along with the survey of imaging procedures reported in the literature. Finally the image analysis based morphological parameters and correlation of the parameters with regard to monitoring and prediction of activated sludge are discussed. Hence it is observed that image analysis can play a very useful role in the monitoring of activated sludge wastewater treatment plants.

  12. Suspended biofilm carrier and activated sludge removal of acidic pharmaceuticals

    DEFF Research Database (Denmark)

    Falås, Per; Baillon-Dhumez, Aude; Andersen, Henrik Rasmus

    2012-01-01

    Removal of seven active pharmaceutical substances (ibuprofen, ketoprofen, naproxen, diclofenac, clofibric acid, mefenamic acid, and gemfibrozil) was assessed by batch experiments, with suspended biofilm carriers and activated sludge from several full-scale wastewater treatment plants. A distinct...... and attached solids for the carriers) of diclofenac, ketoprofen, gemfibrozil, clofibric acid and mefenamic acid compared to the sludges. Among the target pharmaceuticals, only ibuprofen and naproxen showed similar removal rates per unit biomass for the sludges and biofilm carriers. In contrast...

  13. Activated sludge model No. 2d, ASM2d

    DEFF Research Database (Denmark)

    Henze, M.

    1999-01-01

    The Activated Sludge Model No. 2d (ASM2d) presents a model for biological phosphorus removal with simultaneous nitrification-denitrification in activated sludge systems. ASM2d is based on ASM2 and is expanded to include the denitrifying activity of the phosphorus accumulating organisms (PAOs...

  14. Application of forward osmosis (FO) under ultrasonication on sludge thickening of waste activated sludge.

    Science.gov (United States)

    Nguyen, Nguyen Cong; Nguyen, Hau Thi; Chen, Shiao-Shing; Nguyen, Nhat Thien; Li, Chi-Wang

    2015-01-01

    Forward osmosis (FO) is an emerging process for dewatering solid-liquid stream which has the potential to be innovative and sustainable. However, the applications have still been hindered by low water flux and membrane fouling when activated sludge is used as the feed solution due to bound water from microbial cells. Hence, a novel strategy was designed to increase sludge thickening and reduce membrane fouling in the FO process under ultrasonic condition. The results from the ultrasound/FO hybrid system showed that the sludge concentration reached up to 20,400 and 28,400 mg/L from initial sludge concentrations of 3000 and 8000 mg/L with frequency of 40 kHz after 22 hours, while the system without ultrasound had to spend 26 hours to achieve the same sludge concentration. This identifies that the presence of ultrasound strongly affected sludge structure as well as sludge thickening of the FO process. Furthermore, the ultrasound/FO hybrid system could achieve NH4+-N removal efficiency of 96%, PO4(3-)-P of 98% and dissolved organic carbon (DOC) of 99%. The overall performance demonstrates that the proposed ultrasound/FO system using seawater as a draw solution is promising for sludge thickening application.

  15. Immobilization of activated sludge using improved polyvinyl alcohol (PVA) gel

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The microbial immobilization method using polyvinyl alcohol (PVA) gel as an immobilizing material was improved and used for entrapment of activated sludge. The OUR (oxygen uptake rate) was used to characterize the biological activity of immobilized activated sludge. Three kinds of PVA-immobilized particles of activated sludge, that is, PVA-boric acid beads, PVA-sodium nitrate beads and PVA-orthophosphate beads was prepared, and their biological activity was compared by measuring the OUR value. The bioactivity of both autotrophic and heterotrophic microorganisms of activated sludge was determined using different synthetic wastewater media (containing 250 mg/L COD and 25 mg/L NH4+-N). The experimental results showed that the bioactivity and stability of the three kinds of immobilized activated sludge was greatly improved after activation. With respect of the bioactivity and the mechanical stability, the PVA-orthophosphate method may be a promising and economical technique for microbial immobilization.

  16. Preparation of the sludge activated carbon with domestic sludge mixed agricultural straw

    Science.gov (United States)

    Wang, Laifu; Wang, Yan; Lian, Jingyan

    2017-01-01

    Urban sewage sludge with complicated composition produce largely each year, pollution problem and resource utilization has increasingly become the focus of attention. Sewage sludge is utilized to prepare adsorbent that is a new type method. Agricultural stalks was added to material (urban sewage sludge) and activator (ZnCl2), calcined under the condition of no inert gas, and obtained domestic sludge activated carbon. The properties were measured by iodine adsorption value and BET, discussed influence factors of sludge activated carbon preparation, including activator concentration, solid-liquid ratio, calcific temperature and calcific time. The best process condition of orthogonal experiment had explored that activated time is 10 minutes, calcific temperature is 350°C, the activator concentration ZnCl2 is 3 mol/L and the mixing ratio of raw materials and activator is approximately 1:5. The iodine adsorption value and the optimal BET of as-obtained domestic sludge activated carbon is 445.06 mg/g, 525.31m2/g, respectively.

  17. Characteristics of KE Basin Sludge Samples Archived in the RPL - 2007

    Energy Technology Data Exchange (ETDEWEB)

    Delegard, Calvin H.; Schmidt, Andrew J.; Chenault, Jeffrey W.

    2011-11-22

    Samples of sludge were collected from the K East fuel storage basin (KE Basin) floor, contiguous pits (Weasel Pit, North Load Out Pit, Dummy Elevator Pit, and Tech View Pit), and fuel storage canisters between 1995 and 2003 for chemical and radionuclide concentration analysis, physical property determination, and chemical process testing work. Because of the value of the sludge in this testing and because of the cost of obtaining additional fresh samples, an ongoing program of sludge preservation has taken place with the goals to track the sludge identities and preserve, as well as possible, the sludge composition by keeping the sludge in sealed jars and maintaining water coverage on the sludge consistent with the controlling Fluor Hanford (FH) Sampling and Analysis plans and FH contracts with the Pacific Northwest National Laboratory (PNNL). This work was originally initiated to provide material for planned hydrothermal treatment testing in accordance with the test plan for the Sludge Treatment Project (STP) corrosion process chemistry follow on testing (Delegard et al. 2007). Although most of the planned hydrothermal testing was canceled in July 2007 (as described in the forward of Delegard et al. 2007), sample consolidation and characterization was continued to identify a set of well-characterized sludge samples that are suited to support evolving STP initiatives. The work described in the letter was performed by the PNNL under the direction of the Sludge Treatment Project, managed by Fluor Hanford.

  18. Impact of sludge properties on solid-liquid separation of activated sludge

    DEFF Research Database (Denmark)

    Christensen, Morten Lykkegaard

    2016-01-01

    and dissolved extracellular polymeric substances (EPS). Polyvalent ions improve the floc strangth and improve the separation whereas monovalent ions (e.g. from road salt, sea water intrusion and industry) reduces impair the separation. Further high pH impairs the separation process due to floc disintegration......Solid-liquid separation of activated sludge is important both directly after the biological treatment of wastewater and for sludge dewatering. The separation of solid from the treated wastewater can be done by clarifiers (conventional plants) or membrane (MBR). Further, part of the sludge is taken...

  19. Utilization of spent activated carbon to enhance the combustion efficiency of organic sludge derived fuel.

    Science.gov (United States)

    Chen, Wei-Sheng; Lin, Chang-Wen; Chang, Fang-Chih; Lee, Wen-Jhy; Wu, Jhong-Lin

    2012-06-01

    This study examines the heating value and combustion efficiency of organic sludge derived fuel, spent activated carbon derived fuel, and derived fuel from a mixture of organic sludge and spent activated carbon. Spent activated carbon was sampled from an air pollution control device of an incinerator and characterized by XRD, XRF, TG/DTA, and SEM. The spent activated carbon was washed with deionized water and solvent (1N sulfuric acid) and then processed by the organic sludge derived fuel manufacturing process. After washing, the salt (chloride) and sulfide content could be reduced to 99% and 97%, respectively; in addition the carbon content and heating value were increased. Different ratios of spent activated carbon have been applied to the organic sludge derived fuel to reduce the NO(x) emission of the combustion.

  20. Interference sources in ATP bioluminescence assay of silica nanoparticle toxicity to activated sludge.

    Science.gov (United States)

    Sibag, Mark; Kim, Seung Hwan; Kim, Choah; Kim, Hee Jun; Cho, Jinwoo

    2015-06-01

    ATP measurement provides an overview of the general state of microbial activity, and thus it has proven useful for the evaluation of nanoparticle toxicity in activated sludge. ATP bioluminescence assay, however, is susceptible to interference by the components of activated sludge other than biomass. This paper presents the interference identified specific to the use of this assay after activated sludge respiration inhibition test of silica nanoparticles (OECD 209). We observed a high degree of interference (90%) in the presence of 100 mg/L silica nanoparticles and a low level of ATP being measured (0.01 μM); and 30% interference by the synthetic medium regardless of silica nanoparticle concentration and ATP level in the samples. ATP measurement in activated sludge with different MLSS concentrations revealed interference of high biomass content. In conclusion, silica nanoparticles, synthetic medium and activated sludge samples themselves interfere with ATP bioluminescence; this will need to be considered in the evaluation of silica nanoparticle toxicity to activated sludge when this type of assay is used.

  1. Drawing method and device of activated carbon sludge from drums

    Energy Technology Data Exchange (ETDEWEB)

    Ozaki, Shigeru [Toshiba Corp., Kawasaki, Kanagawa (Japan); Kaji, Koichi

    1998-09-11

    Upon drawing out active sludge accumulated while being separated from supernatant water in a drum for containing active sludge generated as residues after the processing of washing liquid generated in a nuclear power plant, the sludge is stirred together with the supernatant water while being scraped off from the surface by using a stirring blade equipped with teeth. Then the sludge in the form of a slurry is drained by a highly viscous fluid transferring-pump. Then accumulated active carbon sludge can be supplied quantitatively as a mayonnaise-like slurry to a furnace. Alternatively, the supernatant water is drawn out at first from a drum, and sludge is discharged to the outside next by using screw blades disposed backward while scraping the sludge from the surface by rotating scraping teeth. With such procedures, there can be provided an advantageous point that the accumulated active carbon sludge can be supplied in a state of small lumps quantitatively to a furnace. (T.M.)

  2. Evaluation of activated sludge treatment and settleability in ...

    African Journals Online (AJOL)

    ... (MLE) activated sludge process was used to treat refinery effluent from the industry. Pre-flocculation of the effluent was necessary to remove the bulk of the fats, ... the flocculated effluent, at a 15 d sludge age and 24 h hydraulic retention time.

  3. Fate of linear alkylbenzene sulfonate (LAS) in activated sludge plants

    NARCIS (Netherlands)

    Temmink, B.G.; Klapwijk, A.

    2004-01-01

    Monitoring data were collected in a pilot-scale municipal activated sludge plant to assess the fate of the C12-homologue of linear alkyl benzene sulfonate (LAS-C12). The pilot-plant was operated at influent LAS-C12 concentrations between 2 and 12 mg/l and at sludge retention times of 10 and 27 days<

  4. Using Boiling for Treating Waste Activated Sludge

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In this work we investigated the feasibility of using short time, low superheat boiling to treat biological sludge. The treated sludge exhibited reduced filterability and enhanced settleability. The boiling treatment released a large amount of extra-cellular polymers (ECPs) from the solid phase and reduced the microbial density levels of the total coliform bacteria and the heterotrophic bacteria. A diluted sludge is preferable for its high degree of organic hydrolysis and sufficient reduction in microbial density levels.

  5. Bacterial composition of activated sludge - importance for floc and sludge properties

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, Per H.; Thomsen, Trine R.; Nielsen, Jeppe L.

    2003-07-01

    Activated sludge flocs consist of numerous constituents which, together with other factors, are responsible for floc structure and floc properties. These properties largely determine the sludge properties such as flocculation, settling and dewaterability. In this paper we briefly review the present knowledge about the role of bacteria in relation to floc and sludge properties, and we present a new approach to investigate the identity and function of the bacteria in the activated sludge flocs. The approach includes identification of the important bacteria and a characterization of their physiological and functional properties. It is carried out by use of culture-independent molecular biological methods linked with other methods to study the physiology and function maintaining a single cell resolution. Using this approach it was found that floc-forming properties differed among the various bacterial groups, e.g. that different microcolony-forming bacteria had very different sensitivities to shear and that some of them deflocculated under anaerobic conditions. in our opinion, the approach to combine identity with functional analysis of the dominant bacteria in activated sludge by in situ methods is a very promising way to investigate correlations between presence of specific bacteria, and floc and sludge properties that are of interest. (author)

  6. SLUDGE BATCH 7B QUALIFICATION ACTIVITIES WITH SRS TANK FARM SLUDGE

    Energy Technology Data Exchange (ETDEWEB)

    Pareizs, J.; Click, D.; Lambert, D.; Reboul, S.

    2011-11-16

    Waste Solidification Engineering (WSE) has requested that characterization and a radioactive demonstration of the next batch of sludge slurry - Sludge Batch 7b (SB7b) - be completed in the Shielded Cells Facility of the Savannah River National Laboratory (SRNL) via a Technical Task Request (TTR). This characterization and demonstration, or sludge batch qualification process, is required prior to transfer of the sludge from Tank 51 to the Defense Waste Processing Facility (DWPF) feed tank (Tank 40). The current WSE practice is to prepare sludge batches in Tank 51 by transferring sludge from other tanks. Discharges of nuclear materials from H Canyon are often added to Tank 51 during sludge batch preparation. The sludge is washed and transferred to Tank 40, the current DWPF feed tank. Prior to transfer of Tank 51 to Tank 40, SRNL typically simulates the Tank Farm and DWPF processes with a Tank 51 sample (referred to as the qualification sample). With the tight schedule constraints for SB7b and the potential need for caustic addition to allow for an acceptable glass processing window, the qualification for SB7b was approached differently than past batches. For SB7b, SRNL prepared a Tank 51 and a Tank 40 sample for qualification. SRNL did not receive the qualification sample from Tank 51 nor did it simulate all of the Tank Farm washing and decanting operations. Instead, SRNL prepared a Tank 51 SB7b sample from samples of Tank 7 and Tank 51, along with a wash solution to adjust the supernatant composition to the final SB7b Tank 51 Tank Farm projections. SRNL then prepared a sample to represent SB7b in Tank 40 by combining portions of the SRNL-prepared Tank 51 SB7b sample and a Tank 40 Sludge Batch 7a (SB7a) sample. The blended sample was 71% Tank 40 (SB7a) and 29% Tank 7/Tank 51 on an insoluble solids basis. This sample is referred to as the SB7b Qualification Sample. The blend represented the highest projected Tank 40 heel (as of May 25, 2011), and thus, the highest

  7. Effect of ultrasonic specific energy on waste activated sludge ...

    African Journals Online (AJOL)

    USER

    2010-03-22

    Mar 22, 2010 ... Full Length Research Paper. Effect of ultrasonic ... Key word: Waste activated sludge (WAS), ultrasonic, solubilization, disintegration degree, enzyme activity. ... burning and land filling, have been carried out for the disposal of ...

  8. Can aquatic worms enhance methane production from waste activated sludge?

    Science.gov (United States)

    Serrano, Antonio; Hendrickx, Tim L G; Elissen, Hellen H J; Laarhoven, Bob; Buisman, Cees J N; Temmink, Hardy

    2016-07-01

    Although literature suggests that aquatic worms can help to enhance the methane production from excess activated sludge, clear evidence for this is missing. Therefore, anaerobic digestion tests were performed at 20 and at 30°C with sludge from a high-loaded membrane bioreactor, the aquatic worm Lumbriculus variegatus, feces from these worms and with mixtures of these substrates. A significant synergistic effect of the worms or their feces on methane production from the high-loaded sludge or on its digestion rate was not observed. However, a positive effect on low-loaded activated sludge, which generally has a lower anaerobic biodegradability, cannot be excluded. The results furthermore showed that the high-loaded sludge provides an excellent feed for L. variegatus, which is promising for concepts where worm biomass is considered a resource for technical grade products such as coatings and glues.

  9. Enhancement of activated sludge disintegration and dewaterability by Fenton process

    Science.gov (United States)

    Heng, G. C.; Isa, M. H.

    2016-06-01

    Municipal and industrial wastewater treatment plants produce large amounts of sludge. This excess sludge is an inevitable drawback inherent to the activated sludge process. In this study, the waste activated sludge was obtained from the campus wastewater treatment plant at Universiti Teknologi PETRONAS (UTP), Malaysia. Fenton pretreatment was optimized by using the response surface methodology (RSM) to study the effects of three operating conditions including the dosage of H2O2 (g H2O2/kg TS), the molar ratio of H2O2/Fe2+ and reaction time. The optimum operating variables to achieve MLVSS removal 65%, CST reduction 28%, sCOD 11000 mg/L and EPS 500 mg/L were: 1000 g H2O2/kg TS, H2O2/Fe2+ molar ratio 70 and reaction time 45 min. Fenton process was proved to be able to enhance the sludge disintegration and dewaterability.

  10. Denitrification, activity of bacterial flocs, and growth of a filamentous bacterium in relation with the bulking of activated sludge

    NARCIS (Netherlands)

    Krul, J.M.

    1978-01-01

    Activated sludge with poor settling characteristics is caught under the term "bulking" sludge. Various types of bulking activated sludge can be distinguished.
    1) Sludge containing an abundance of filamentous microorganisms.
    2) Sludge, characterized by excessive amount of

  11. Denitrification, activity of bacterial flocs, and growth of a filamentous bacterium in relation with the bulking of activated sludge

    NARCIS (Netherlands)

    Krul, J.M.

    1978-01-01

    Activated sludge with poor settling characteristics is caught under the term "bulking" sludge. Various types of bulking activated sludge can be distinguished.
    1) Sludge containing an abundance of filamentous microorganisms.
    2) Sludge, characterized by excessive amount of bacteria

  12. Denitrification, activity of bacterial flocs, and growth of a filamentous bacterium in relation with the bulking of activated sludge

    NARCIS (Netherlands)

    Krul, J.M.

    1978-01-01

    Activated sludge with poor settling characteristics is caught under the term "bulking" sludge. Various types of bulking activated sludge can be distinguished.1) Sludge containing an abundance of filamentous microorganisms.2) Sludge, characterized by excessive amount of bacterial slime.3) Flotating s

  13. STP K Basin Sludge Sample Archive at the Pacific Northwest National Laboratory FY2014

    Energy Technology Data Exchange (ETDEWEB)

    Fiskum, Sandra K.; Smoot, Margaret R.; Schmidt, Andrew J.

    2014-06-01

    The Pacific Northwest National Laboratory (PNNL) currently houses 88 samples (~10.5 kg) of K Basin sludge (81 wet and seven dry samples) on behalf of the Sludge Treatment Project (STP), which is managed for the U.S. Department of Energy (DOE) by the CH2M Hill Plateau Remediation Company (CHPRC). Selected samples are intended to serve, in part, as sentinels to enhance understanding of sludge properties after long-term storage, and thus enhance understanding of sludge behavior following transfer to sludge transfer and storage containers (STSCs) and storage at the Hanford 200 Area central plateau. In addition, remaining samples serve in contingency for future testing requirements. At PNNL, the samples are tracked and maintained under a prescriptive and disciplined monthly sample-monitoring program implemented by PNNL staff. This report updates the status of the K Basin archive sludge sample inventory to April 2014. The previous inventory status report, PNNL 22245 (Fiskum et al. 2013, limited distribution report), was issued in February of 2013. This update incorporates changes in the inventory related to repackaging of 17 samples under test instructions 52578 TI052, K Basin Sludge Sample Repackaging for Continued Long Term Storage, and 52578 TI053, K Basin Sludge Sample Repackaging Post-2014 Shear Strength Measurements. Note that shear strength measurement results acquired in 2014 are provided separately. Specifically, this report provides the following: • a description of the K Basin sludge sample archive program and the sample inventory • a summary and images of the samples that were repackaged in April 2014 • up-to-date images and plots of the settled density and water loss from all applicable samples in the inventory • updated sample pedigree charts, which provide a roadmap of the genesis and processing history of each sample in the inventory • occurrence and deficiency reports associated with sample storage and repackaging

  14. Polyphosphate Kinase from Activated Sludge Performing Enhanced Biological Phosphorus Removal†

    Science.gov (United States)

    McMahon, Katherine D.; Dojka, Michael A.; Pace, Norman R.; Jenkins, David; Keasling, Jay D.

    2002-01-01

    A novel polyphosphate kinase (PPK) was retrieved from an uncultivated organism in activated sludge carrying out enhanced biological phosphorus removal (EBPR). Acetate-fed laboratory-scale sequencing batch reactors were used to maintain sludge with a high phosphorus content (approximately 11% of the biomass). PCR-based clone libraries of small subunit rRNA genes and fluorescent in situ hybridization (FISH) were used to verify that the sludge was enriched in Rhodocyclus-like β-Proteobacteria known to be associated with sludges carrying out EBPR. These organisms comprised approximately 80% of total bacteria in the sludge, as assessed by FISH. Degenerate PCR primers were designed to retrieve fragments of putative ppk genes from a pure culture of Rhodocyclus tenuis and from organisms in the sludge. Four novel ppk homologs were found in the sludge, and two of these (types I and II) shared a high degree of amino acid similarity with R. tenuis PPK (86 and 87% similarity, respectively). Dot blot analysis of total RNA extracted from sludge demonstrated that the Type I ppk mRNA was present, indicating that this gene is expressed during EBPR. Inverse PCR was used to obtain the full Type I sequence from sludge DNA, and a full-length PPK was cloned, overexpressed, and purified to near homogeneity. The purified PPK has a specific activity comparable to that of other PPKs, has a requirement for Mg2+, and does not appear to operate in reverse. PPK activity was found mainly in the particulate fraction of lysed sludge microorganisms. PMID:12324346

  15. Comparison of different treatment methods for protein solubilisation from waste activated sludge.

    Science.gov (United States)

    Xiao, Keke; Chen, Yun; Jiang, Xie; Seow, Wan Yi; He, Chao; Yin, Yao; Zhou, Yan

    2017-10-01

    Biomaterials recovery from wasted activated sludge has become an increasing interesting research topic. The purpose of this study was to systemically evaluate different sludge disintegration methods (ultrasonic, alkaline, and thermal treatments) for protein solubilisation from waste activated sludge (WAS). Compared to control without treatment, the soluble protein concentration increased by 11, 23 and 12 times under the optimal treatment conditions (ultrasonic treatment of 1 W mL(-1), alkaline treatment of pH 12 and thermal treatment at 80 °C). The increased soluble protein were significantly correlated with the release of total organic carbon (TOC), total dissolved nitrogen (TDN) and total organic nitrogen (TON) in soluble EPS, and the degradation of above parameters in tightly bound EPS. For all sludge samples treated by various methods, tyrosine-like protein with molecular weight less than 20 kDa predominated, and alkaline treatment at pH 12 showed the highest protein dominance. Further surface analysis of sludge by X-ray photoelectron spectroscopy indicated this might be related with the significant protein-N conversion occurred at pH 12. The economic analysis indicated alkaline treatment at pH 12 was economically feasible with a net saving of 25.57 USD per ton wet sludge compared to conventional sludge treatment and disposal method. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Characterization of tank 51 sludge samples (HTF-51-17-44/ HTF-51-17-48) in support of sludge batch 10 processing

    Energy Technology Data Exchange (ETDEWEB)

    Oji, L. N. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-08-17

    The Savannah River National Laboratory (SRNL) was requested by Savannah River Remediation (SRR) Engineering (SRR-E) to provide sample characterization and analyses of Tank 51 sludge samples in support of Sludge Batch (SB) 10. The two Tank 51 sludge samples were sampled and delivered to SRNL in May of 2017. These two tank 51 sludge samples were combined into one composite sample and analyzed for corrosion controls analytes, select radionuclides, chemical elements, density and weight percent total solids and aluminum hydroxides (gibbsite and boehmite) by x-ray diffraction.

  17. On-line Measurements of Settling Charateristics in Activated Sludge

    DEFF Research Database (Denmark)

    Rasmussen, Michael R.; Larsen, Torben

    1997-01-01

    An on-line settling column for measuring the dynamic variations of settling velocity of activated sludge has been developed. The settling column is automatic and self-cleansing insuring continuous and reliable measurements. The settling column was tested on sludge from a batch reactor where sucrose...... was added as an impulse to activated sludge. The continuous measurement of settling velocity revealed a highly dynamic response after the sucrose was added. The result were verified with simultaneous measurement of the initial settling rate. A 200 hour experiment showed variations in settling velocity...

  18. Characterization of the SRNL-Washed tank 51 sludge batch 9 qualification sample

    Energy Technology Data Exchange (ETDEWEB)

    Pareizs, J. M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-01-01

    Savannah River National Laboratory (SRNL) personnel have been requested to qualify the next sludge batch (Sludge Batch 9 – SB9) for processing at the Defense Waste Processing Facility (DWPF). To accomplish this task, Savannah River Remediation (SRR) sent SRNL a 3-L sample of Tank 51H slurry to be characterized, washed, and then used in a lab-scale demonstration of the DWPF flowsheet (after combining with Tank 40H sludge). SRNL has washed the Tank 51H sample per the Tank Farm washing strategy as of October 20, 2015. A part of the qualification process is extensive radionuclide and chemical characterization of the SRNL-washed Tank 51H slurry. This report documents the chemical characterization of the washed slurry; radiological characterization is in progress and will be documented in a separate report. The analytical results of this characterization are comparable to the Tank Farm projections. Therefore, it is recommended that SRNL use this washed slurry for the ongoing SB9 qualification activities.

  19. Evaluation of activated sludge treatment and settleability in ...

    African Journals Online (AJOL)

    DRINIE

    2003-07-03

    Jul 3, 2003 ... Pre-flocculation of the effluent was necessary to remove the bulk of the fats, oils and ... phosphorus, sulphate and various other pollutants and owing to the ... biological treatment of edible oil effluent using activated sludge.

  20. Sampling and analysis of radioactive liquid wastes and sludges in the Melton Valley and evaporator facility storage tanks at ORNL

    Energy Technology Data Exchange (ETDEWEB)

    Sears, M.B.; Botts, J.L.; Ceo, R.N.; Ferrada, J.J.; Griest, W.H.; Keller, J.M.; Schenley, R.L.

    1990-09-01

    The sampling and analysis of the radioactive liquid wastes and sludges in the Melton Valley Storage Tanks (MVSTs), as well as two of the evaporator service facility storage tanks at ORNL, are described. Aqueous samples of the supernatant liquid and composite samples of the sludges were analyzed for major constituents, radionuclides, total organic carbon, and metals listed as hazardous under the Resource Conservation and Recovery Act (RCRA). Liquid samples from five tanks and sludge samples from three tanks were analyzed for organic compounds on the Environmental Protection Agency (EPA) Target Compound List. Estimates were made of the inventory of liquid and sludge phases in the tanks. Descriptions of the sampling and analytical activities and tabulations of the results are included. The report provides data in support of the design of the proposed Waste Handling and Packaging Plant, the Liquid Low-Level Waste Solidification Project, and research and development activities (R D) activities in developing waste management alternatives. 7 refs., 8 figs., 16 tabs.

  1. Modelling of Activated Sludge Wastewater Treatment

    Directory of Open Access Journals (Sweden)

    Kurtanjeka, Ž.

    2008-02-01

    Full Text Available Activated sludge wastewater treatment is a highly complex physical, chemical and biological process, and variations in wastewater flow rate and its composition, combined with time-varying reactions in a mixed culture of microorganisms, make this process non-linear and unsteady. The efficiency of the process is established by measuring the quantities that indicate quality of the treated wastewater, but they can only be determined at the end of the process, which is when the water has already been processed and is at the outlet of the plant and released into the environment.If the water quality is not acceptable, it is already too late for its improvement, which indicates the need for a feed forward process control based on a mathematical model. Since there is no possibility of retracing the process steps back, all the mistakes in the control of the process could induce an ecological disaster of a smaller or bigger extent. Therefore, models that describe this process well may be used as a basis for monitoring and optimal control of the process development. This work analyzes the process of biological treatment of wastewater in the Velika Gorica plant. Two empirical models for the description of the process were established, multiple linear regression model (MLR with 16 predictor variables and piecewise linear regression model (PLR with 17 predictor variables. These models were developed with the aim to predict COD value of the effluent wastewater at the outlet, after treatment. The development of the models is based on the statistical analysis of experimental data, which are used to determine the relations among individual variables. In this work are applied linear models based on multiple linear regression (MLR and partial least squares (PLR methods. The used data were obtained by everyday measurements of the quantities that indicate the quality of the input and output water, working conditions of the plant and the quality of the activated sludge

  2. COMPARISON BETWEEN DIFFERENT MODELS FOR RHEOLOGICAL CHARACTERIZATION OF ACTIVATED SLUDGE

    Directory of Open Access Journals (Sweden)

    A. H. Khalili Garakani

    2011-09-01

    Full Text Available Activated sludge flow rheology is a very complicated phenomenon. Studies related to activated sludge tend to classify sludge as non-Newtonian fluid. Until now, several theories have been built to describe the complex behavior of activated sludge with varying degrees of success. In this article, seven different models for viscosity of non-Newtonian fluids (i.e., Power law, Bingham plastic, Herschel-Bulkley, Casson, Sisko, Carreau and Cross were considered to evaluate their predictive capability of apparent viscosity of activated sludge. Results showed that although evaluating the constants in the four-parameter models is difficult, they provide the best prediction of viscosity in the whole range of shear rates for activated sludge. For easier prediction of viscosity at different mixed liquor suspended solids (2.74-31g/L, temperature (15-25°C and shear rate (1-1000/s, simple correlations were proposed. Comparing the results with the experimental data revealed that the proposed correlations are in good agreement with real apparent viscosities.

  3. Purification of total DNA extracted from activated sludge

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Purification of the total DNA extracted from activated sludge samples was studied. The effects of extraction buffers and lysis treatments (lysozyme, sodium dodecyl sulfate (SDS), sonication, mechanical mill and thermal shock) on yield and purity of the total DNA extracted from activated sludge were investigated. It was found that SDS and mechanical mill were the most effective ways for cell lysis, and both gave the highest DNA yields, while by SDS and thermal shock, the purest DNA extract could be obtained. The combination of SDS with other lysis treatment, such as sonication and thermal shock, could apparently increase the DNA yields but also result in severe shearing. For the purification of the crude DNA extract, polyvinyl polypyrrolidone was used for the removal of humic contaminants. Cetyltrimethyl ammonium bromide, potassium acetate and phenol/chloroform were used to remove proteins and polysaccharides from crude DNA. Crude DNA was further purified by isopropanol precipitation. Thus, a suitable protocol was proposed for DNA extraction, yielding about 49.9 mg (DNA)/g volatile suspended solids, and the DNA extracts were successfully used in PCR amplifications for 16S rDNA and 16S rDNA V3 region. The PCR products of 16S rDNA V3 region allowed the DGGE analysis (denatured gradient gel electrophoresis) to be possible.

  4. Nitrogen in the Process of Waste Activated Sludge Anaerobic Digestion

    Directory of Open Access Journals (Sweden)

    Suschka Jan

    2014-07-01

    Full Text Available Primary or secondary sewage sludge in medium and large WWTP are most often processed by anaerobic digestion, as a method of conditioning, sludge quantity minimization and biogas production. With the aim to achieve the best results of sludge processing several modifications of technologies were suggested, investigated and introduced in the full technical scale. Various sludge pretreatment technologies before anaerobic treatment have been widely investigated and partially introduced. Obviously, there are always some limitations and some negative side effects. Selected aspects have been presented and discussed. The problem of nitrogen has been highlighted on the basis of the carried out investigations. The single and two step - mesophilic and thermophilic - anaerobic waste activated sludge digestion processes, preceded by preliminary hydrolysis were investigated. The aim of lab-scale experiments was pre-treatment of the sludge by means of low intensive alkaline and hydrodynamic disintegration. Depending on the pretreatment technologies and the digestion temperature large ammonia concentrations, up to 1800 mg NH4/dm3 have been measured. Return of the sludge liquor to the main sewage treatment line means additional nitrogen removal costs. Possible solutions are discussed.

  5. Hydrogen sulphide removal by activated sludge diffusion.

    Science.gov (United States)

    Barbosa, V L; Dufol, D; Callan, J L; Sneath, R; Stuetz, R M

    2004-01-01

    Odours from wastewater treatment plants comprise a mixture of various gases, of which hydrogen sulphide (H2S) is the main constituent. Microorganisms commonly found in wastewater can degrade sulphurous compounds. Therefore, the use of activated sludge (AS) for odour control offers an alternative to traditional waste gas treatment processes, such as biofilters, bioscrubbers and biotrickling filters, both in practical terms (use of existing facilities) and economically (minimal capital cost). The performance of AS diffusion as a bioscrubber for removing H2S at concentrations at 25, 75 and 150 ppmv was evaluated. Pilot-scale trials were undertaken using parallel 60-L aeration tanks and 20-L clarifier reactors at the Bedford Sewage Treatment Works, Carington, UK. Olfactometry measurements were also carried out to determine whether there was any increase in odour concentration owing to H2S diffusion. Hydrogen sulphide removal rates of 100% were obtained, with no noticeable increase in odour concentration throughout the trials as measured by olfactometry. Odour concentration was highest at the beginning of the trials and lowest during the high H2S dosing period, with similar values being obtained for test and control. It was concluded that AS diffusion is an effective bioscrubber for the removal of H2S odour.

  6. Application of Gamma irradiation in treatment of Waste Activated Sludge to Obtain Class a Biosolids

    Directory of Open Access Journals (Sweden)

    Mohammed I. AL-Ghonaiem

    2010-01-01

    Full Text Available Problem statement: The main objective of the current study was investigation of the possible application of Gamma irradiation for treatment of the activated sludge generated wastewater treatment stations, to achieve the standard requirements in term of pathogens content. Approach: Activated sludge samples were collected from Riyadh wastewater plant and analyzed quantitatively for the presence of important bacterial parameters including fecal coliforms and Salmonella spp. The collected samples were treated with various doses of Gamma irradiation and bacterial count was determined. Results: The results indicated that all tested sludge samples were positive for the presence of fecal coliforms and Salmonella spp, with different counts in different stages of wastewater treatment. The raw sludge showed to have the highest coliforms and Salmonella spp counts of 1.1×108 and 2×103 MPN g-1 dry sludge, respectively. Furthermore, coliforms and Salmonella spp were detected in final resulted sludge with count of 2.5×107 and 6×102 MPN g-1 dry sludge, respectively. It was found that treatment of samples with gamma irradiation was able to reduce the fecal coliforms and Salmonella spp effectively and the reduction efficiency was increased by increasing the irradiation dose. Fecal coliforms and Salmonella counts were reduced to less than 100 MPN g-1 dry sludge by exposing to 1.5 and 0.25 kGy respectively. Furthermore, Gamma radiation dose of 2.0 kGy was able to remove both fecal coliforms and Salomnella spp completely. In addition, D10 values were determined and was found to be 0.25 and 0.24 kGy for fecal coliforms and Salmonella spp., respectively. Conclusion/Recommendations: The results indicating that the resulted activated sludge generated from Riyadh wastewater plant are rich with important pathogens and therefore further treatment procedures are necessary to achieve the required standards, before any land application. Application of

  7. Evaluation of control parameters of the activated sludge process

    Energy Technology Data Exchange (ETDEWEB)

    Stall, T.R.; Sherrard, J.H.

    1978-03-01

    The evaluation of control parameters of the activated sludge process was effected with a laboratory-scale, completely mixed process employing internal cell recycle and an artificial wasterwater over a wide spectrum of conditions at full-scale facilities. The parameters: food-microorganism ratio, specific utilization rate, COD or BOD sludge age, and aeration and total system mean cell residence time can all be used to control an activated sludge wastewater treatment plant. Because of the sensitivity of the COD or BOD sludge age (when compared with measures of mean cell residence time), its use may be of limited value. The aeration basin cell residence time may be favored over the total system mean cell residence time because of the ease in measuring aeration basin solids and the difficulty in measuring solids concentration at the bottom of the secondary clarifier and in the recycle line.

  8. Effects of Heavy Metals on Activated Sludge Microorganism

    Institute of Scientific and Technical Information of China (English)

    XIE Bing; XI Dan-li; CHEN Ji-hua

    2002-01-01

    The efforts of heavy metals on activated sludge microorganisms are reviewed. Although some heavy metals play an important role in the life of microorganism, heavy metals concentrations above toxic levels inhibit biological processes. Copper, zinc, nickel,cadmium and chromium were mostly studied because of their toxicity and widely used, regardless of single or combination. The microorganism response to these heavy metals varied with species and concentrations of metals,factors such as pH, sludge age, MLSS etc. also affect toxicity on the microorganism. The acclimation could extend the microorganism tolerance of heavy metals. The effects of heavy metals on sludge microorganisms could be described with different models, such as Sigmoidal and Monod equation. The kinetic constants are the useful indexes to estimate the heavy metals inhibition on activated sludge system. Methods to measure the toxicity and effects on microorganism community were also reviewed.

  9. Production and characterization of granular activated carbon from activated sludge

    Directory of Open Access Journals (Sweden)

    Z. Al-Qodah

    2009-03-01

    Full Text Available In this study, activated sludge was used as a precursor to prepare activated carbon using sulfuric acid as a chemical activation agent. The effect of preparation conditions on the produced activated carbon characteristics as an adsorbent was investigated. The results indicate that the produced activated carbon has a highly porous structure and a specific surface area of 580 m²/g. The FT-IR analysis depicts the presence of a variety of functional groups which explain its improved adsorption behavior against pesticides. The XRD analysis reveals that the produced activated carbon has low content of inorganic constituents compared with the precursor. The adsorption isotherm data were fitted to three adsorption isotherm models and found to closely fit the BET model with R² equal 0.948 at pH 3, indicating a multilayer of pesticide adsorption. The maximum loading capacity of the produced activated carbon was 110 mg pesticides/g adsorbent and was obtained at this pH value. This maximum loading was found experimentally to steeply decrease as the solution pH increases. The obtained results show that activated sludge is a promising low cost precursor for the production of activated carbon.

  10. Chitosan use in chemical conditioning for dewatering municipal-activated sludge.

    Science.gov (United States)

    Zemmouri, H; Mameri, N; Lounici, H

    2015-01-01

    This work aims to evaluate the potential use of chitosan as an eco-friendly flocculant in chemical conditioning of municipal-activated sludge. Chitosan effectiveness was compared with synthetic cationic polyelectrolyte Sedipur CF802 (Sed CF802) and ferric chloride (FeCl₃). In this context, raw sludge samples from Beni-Messous wastewater treatment plant (WWTP) were tested. The classic jar test method was used to condition sludge samples. Capillary suction time (CST), specific resistance to filtration (SRF), cakes dry solid content and filtrate turbidity were analyzed to determine filterability, dewatering capacity of conditioned sludge and the optimum dose of each conditioner. Data exhibit that chitosan, FeCl₃and Sed CF802 improve sludge dewatering. Optimum dosages of chitosan, Sed CF802 and FeCl₃allowing CST values of 6, 5 and 9 s, were found, respectively, between 2-3, 1.5-3 and 6 kg/t ds. Both polymers have shown faster water removal with more permeable sludge. SRF values were 0.634 × 10¹², 0.932 × 10¹² and 2 × 10¹² m/kg for Sed CF802, chitosan and FeCl₃respectively. A reduction of 94.68 and 87.85% of the filtrate turbidity was obtained with optimal dosage of chitosan and Sed CF802, respectively. In contrast, 54.18% of turbidity abatement has been obtained using optimal dosage of FeCl₃.

  11. Cometabolic degradation of organic wastewater micropollutants by activated sludge and sludge-inherent microorganisms.

    Science.gov (United States)

    Fischer, Klaus; Majewsky, Marius

    2014-08-01

    Municipal wastewaters contain a multitude of organic trace pollutants. Often, their biodegradability by activated sludge microorganisms is decisive for their elimination during wastewater treatment. Since the amounts of micropollutants seem too low to serve as growth substrate, cometabolism is supposed to be the dominating biodegradation process. Nevertheless, as many biodegradation studies were performed without the intention to discriminate between metabolic and cometabolic processes, the specific contribution of the latter to substance transformations is often not clarified. This minireview summarizes current knowledge about the cometabolic degradation of organic trace pollutants by activated sludge and sludge-inherent microorganisms. Due to their relevance for communal wastewater contamination, the focus is laid on pharmaceuticals, personal care products, antibiotics, estrogens, and nonylphenols. Wherever possible, reference is made to the molecular process level, i.e., cometabolic pathways, involved enzymes, and formed transformation products. Particular cometabolic capabilities of different activated sludge consortia and various microbial species are highlighted. Process conditions favoring cometabolic activities are emphasized. Finally, knowledge gaps are identified, and research perspectives are outlined.

  12. Contamination of PAHs in Sludge Samples from the Yangtze River Delta Area

    Institute of Scientific and Technical Information of China (English)

    SHEN Rong-Yan; LUO Yong-Ming; ZHANG Gang-Ya; TENG Ying; LI Zhen-Gao; WU Long-Hua

    2007-01-01

    To ascertain the contaminated conditions of polycyclic aromatic hydrocarbons (PAHs) in sludge and to evaluate the risk of application of this sludge for agricultural purposes, 44 sludge samples obtained from 15 cities in the Yangtze River Delta area of China were investigated using capillary gas chromatography/mass spectrometry (GC/MS) after ultrasonic extraction and silica gel cleanup. PAHs' contents ranged from 0.0167 to 15.4860 mg kg-1 (dry weight, DW) and averaged 1.376 mg kg-1, with most samples containing<1.5 mg kg-1. Pyrene (PY), fluoranthene (FL), benzo[b]fluoranthene (BbF), indeno[1,2,3-cd]pyrene (IND), benzo[a]pyrene (B[a]P), and benzo[g,h,i]perylene (BghiP) were the most dominant compounds, ranging from 0.1582 to 0.2518 mg kg-1. Single PAH, such as naphthalene (NAP, 2-benzene rings), phenan-threne (PA, 3-benzene rings), PY (4-benzene rings), and FL (3-benzene rings), had high detection rates (76.1%-93.5%). The distribution patterns of PAHs were found to vary with the sludge samples; however, the patterns showed that a few compounds with 2- and 3-benzene rings were commonly found in the samples, whereas those with 4-, 5-, and 6-benzene rings were usually less commonly found. All the 44 sludge samples were within the B[a]P concentration limit for sludge applied to agricultural land in China (< 3.0 mg kg-1). The probable sources of PAH contamination in the sludge samples were petroleum, petroleum products, and combustion of liquid and solid fuel. The concentrations and distributions of the 16 PAHs in sludge were related to sludge type, source, and treatment technology, together with the physicochemical properties.

  13. Exploring the potential of applying proteomics for tracking bisphenol A and nonylphenol degradation in activated sludge.

    Science.gov (United States)

    Collado, Neus; Buttiglieri, Gianluigi; Kolvenbach, Boris A; Comas, Joaquim; Corvini, Philippe F-X; Rodríguez-Roda, Ignasi

    2013-02-01

    A significant percentage of bisphenol A and nonylphenol removal in municipal wastewater treatment plants relies on biodegradation. Nonetheless, incomplete information is available concerning their degradation pathways performed by microbial communities in activated sludge systems. Hydroquinone dioxygenase (HQDO) is a specific degradation marker enzyme, involved in bisphenol A and nonylphenol biodegradation, and it can be produced by axenic cultures of the bacterium Sphingomonas sp. strain TTNP3. Proteomics, a technique based on the analysis of microbial community proteins, was applied to this strain. The bacterium proteome map was obtained and a HQDO subunit was successfully identified. Additionally, the reliability of the applied proteomics protocol was evaluated in activated sludge samples. Proteins belonging to Sphingomonas were searched at decreasing biomass ratios, i.e. serially diluting the bacterium in activated sludge. The protein patterns were compared and Sphingomonas proteins were discriminated against the ones from sludge itself on 2D-gels. The detection limit of the applied protocol was defined as 10(-3) g TTNP3 g(-1) total suspended solids (TSSs). The results proved that proteomics can be a promising methodology to assess the presence of specific enzymes in activated sludge samples, however improvements of its sensitivity are still needed.

  14. The abundance and diversity of ammonia-oxidizing bacteria in activated sludge under autotrophic domestication.

    Science.gov (United States)

    Li, Qiang; Ma, Chao; Sun, Shifang; Xie, Hui; Zhang, Wei; Feng, Jun; Song, Cunjiang

    2013-04-01

    Ammonia-oxidizing bacteria (AOB) play a key role in nitrogen-removal wastewater treatment plants (WWTPs) as they can transform ammonia into nitrite. AOB can be enriched in activated sludge through autotrophic domestication although they are difficult to be isolated. In this study, autotrophic domestication was carried out in a lab-scale sequencing-batch-reactor (SBR) system with two activated sludge samples. The ammonia removal capacity of the sludge samples increased during the domestication, and pH exhibited a negative correlation with the ammonia removal amount, which indicated that it was one important factor of microbial ammonia oxidation. The count of AOB, measured by the most probable number (MPN) method, increased significantly during autotrophic domestication as ammonia oxidation efficiency was enhanced. We investigated the changes in the community structure of AOB before and after domestication by amoA clone library and T-RFLP profile. It showed that AOB had been successfully enriched and the community structure significantly shifted during the domestication. Two groups of AOB were found in sludge samples: Nitrosomonas-like group remained predominant all the time and Nitrosospira-like group changed obviously. Simultaneously, the total heterotrophic bacteria were investigated by MPN and Biolog assay. The metabolic diversity of heterotrophs had changed minutely, although the count of them decreased significantly and lost superiority of microbial communities in the sludge.

  15. Gas chromatographic analysis of polyhydroxybutyrate in activated sludge: a round-robin test.

    Science.gov (United States)

    Baetens, D; Aurola, A M; Foglia, A; Dionisi, D; van Loosdrecht, M C M

    2002-01-01

    Polyhydroxyalkanoates (PHA) and poly-beta-hydroxybutyrate (PHB) in particular have become compounds which is routinely investigated in wastewater research. The PHB analysis method has only recently been applied to activated sludge samples where PHA contents might be relatively low. This urges the need to investigate the reproducibility of the gas chromatographic method for PHB analysis. This was evaluated in a round-robin test in 5 European laboratories with samples from lab-scale and full-scale enhanced biological phosphorus removal systems. It was shown that the standard deviation of measurements in each lab and the reproducibility between the labs was very good. Experimental results obtained by different laboratories using this analysis method can be compared. Sludge samples with PHB contents varying between 0.3 and 22.5 mg PHB/mg sludge were analysed. The gas chromatographic method allows for PHV, PH2MB and PH2MV analysis as well.

  16. Anaerobic bioleaching of metals from waste activated sludge

    Energy Technology Data Exchange (ETDEWEB)

    Meulepas, Roel J.W., E-mail: roel.meulepas@wetsus.nl [UNESCO-IHE, Westvest 7, 2611 AX Delft (Netherlands); Gonzalez-Gil, Graciela [UNESCO-IHE, Westvest 7, 2611 AX Delft (Netherlands); King Abdullah University of Science and Technology, Water Desalination and Reuse Center, Thuwal 13955-69000 (Saudi Arabia); Teshager, Fitfety Melese; Witharana, Ayoma [UNESCO-IHE, Westvest 7, 2611 AX Delft (Netherlands); Saikaly, Pascal E. [King Abdullah University of Science and Technology, Water Desalination and Reuse Center, Thuwal 13955-69000 (Saudi Arabia); Lens, Piet N.L. [UNESCO-IHE, Westvest 7, 2611 AX Delft (Netherlands)

    2015-05-01

    Heavy metal contamination of anaerobically digested waste activated sludge hampers its reuse as fertilizer or soil conditioner. Conventional methods to leach metals require aeration or the addition of leaching agents. This paper investigates whether metals can be leached from waste activated sludge during the first, acidifying stage of two-stage anaerobic digestion without the supply of leaching agents. These leaching experiments were done with waste activated sludge from the Hoek van Holland municipal wastewater treatment plant (The Netherlands), which contained 342 μg g{sup −1} of copper, 487 μg g{sup −1} of lead, 793 μg g{sup −1} of zinc, 27 μg g{sup −1} of nickel and 2.3 μg g{sup −1} of cadmium. During the anaerobic acidification of 3 g{sub dry} {sub weight} L{sup −1} waste activated sludge, 80–85% of the copper, 66–69% of the lead, 87% of the zinc, 94–99% of the nickel and 73–83% of the cadmium were leached. The first stage of two-stage anaerobic digestion can thus be optimized as an anaerobic bioleaching process and produce a treated sludge (i.e., digestate) that meets the land-use standards in The Netherlands for copper, zinc, nickel and cadmium, but not for lead. - Highlights: • Heavy metals were leached during anaerobic acidification of waste activated sludge. • The process does not require the addition of chelating or oxidizing agents. • The metal leaching efficiencies (66 to 99%) were comparable to chemical leaching. • The produced leachate may be used for metal recovery and biogas production. • The produced digested sludge may be used as soil conditioner.

  17. Low intensity ultrasound stimulates biological activity of aerobic activated sludge

    Institute of Scientific and Technical Information of China (English)

    LIU Hong; YAN Yixin; WANG Wenyan; YU Yongyong

    2007-01-01

    This work aims to explore a procedure to improve biological wastewater treatment efficiency using low intensity ultrasound.The aerobic activated sludge from a municipal wastewater treatment plant was used as the experimental material.Oxygen uptake rate(OUR)of the activated sludge (AS)was determined to indicate the changes of AS activity stimulated by ultrasound at 35 kHZ for 0-40 min with ultrasonic intensities of 0-1.2 W/cm2.The highest OUR was observed at the ultrasonic intensity of 0.3 W/cm2 and an irradiation period of 10 min;more than 15% increase was achieved immediately after sonication.More significantly,the AS activity stimulated by ultrasound could last 24 h after sonication,and the AS activity achieved its peak value within 8 h after sonication.or nearly 100% higher than the initial level after sonication.Therefore,to improve the wastewater treatment efficiency of bioreactors,ultrasound with an intensity of 0.3 W/cm2 could be employed to irradiate a part of the AS in the bioreactor for 10 min every 8 h.

  18. Ciliated protozoa community of a combined UASB-activated sludge system in southeastern Brazil.

    Science.gov (United States)

    Siqueira-Castro, Isabel Cristina Vidal; Greinert-Goulart, Juliane Araújo; Rossetto, Renato; Guimarães, José Roberto; Franco, Regina Maura Bueno

    2016-12-01

    The aims of the present study were (1) to evaluate the abundance and taxonomic composition of ciliated protozoa in the activated sludge of a full-scale combined anaerobic-aerobic system operating in a tropical country and (2) to study the relationship between the effluent quality, the physicochemical variables, and the ciliates present in the operating system. The total ciliate fauna of the activated sludge of the Piçarrão Wastewater Treatment Plant (Piçarrão WWTP) was composed of 36 morphospecies belonging to 33 genera. These included 21 species observed in the activated sludge samples on the day of collection and 15 species found in cultures. The activated sludge of the Piçarrão WWTP contained a diversified ciliate community composed mainly of indicator organisms. The most frequently occurring morphospecies were Aspidisca cicada, Vorticella spp., Gastronauta aloisi, Acineria uncinata, and Epistylis plicatilis complex. These results showed that satisfactory operating conditions prevailed at the Piçarrão WWTP. In the combined UASB-activated sludge system, the presence of Aspidisca cicada suggests the occurrence of denitrification in the process while the presence of Acineria uncinata and G. alosi indicates the removal of carbonaceous organic matter.

  19. Parasite contamination (helminth eggs) in sludge treatment plants: definition of a sampling strategy.

    Science.gov (United States)

    Gaspard, Philippe G; Schwartzbrod, Janine

    2003-03-01

    The use of sludge in agriculture must be carried out according to many guidelines, especially regarding a precise knowledge of the pathogenic microorganisms it contains. The control of the produced sludge requires a sampling strategy that is representative of the contamination present in the sludge. Thus, we evaluated the distribution of helminth eggs in sludge to determine how to sample and at what frequency. Two plants were studied, firstly we studied sludge that was undergoing biological treatment (anaerobic digestion, prolonged aeration), secondly we evaluated the dehydration step (centrifugation and filter press). The helminth egg concentrations were measured over short periods (between 5 minutes and 7 hours) and for periods of over 24 hours (7 to 28 days). The results showed that there was much homogeneity in periods of less than 7 hours, thus it was advisable to take grab samples. An appropriate sample weight was 30 g dry matter, because this allowed an analysis in triplicate when testing treatment processes according to standards of France, (less than 3 viable eggs/10 g dry matter). Determination of the egg concentration in the plants during periods of over 24 hours showed that the parasite flow was stable. In some cases, large variations were due to the treatment processes (storage or thickening, mixing of different sludges). These results have been confirmed with the study of 6 other plants during a one year period. Thus, the recommended sampling frequency can be limited to every 3 to 6 months, by adapting the sampling methods to the characteristics of the plant.

  20. Anaerobic bioleaching of metals from waste activated sludge

    KAUST Repository

    Meulepas, Roel J W

    2015-05-01

    Heavy metal contamination of anaerobically digested waste activated sludge hampers its reuse as fertilizer or soil conditioner. Conventional methods to leach metals require aeration or the addition of leaching agents. This paper investigates whether metals can be leached from waste activated sludge during the first, acidifying stage of two-stage anaerobic digestion without the supply of leaching agents. These leaching experiments were done with waste activated sludge from the Hoek van Holland municipal wastewater treatment plant (The Netherlands), which contained 342μgg-1 of copper, 487μgg-1 of lead, 793μgg-1 of zinc, 27μgg-1 of nickel and 2.3μgg-1 of cadmium. During the anaerobic acidification of 3gdry weightL-1 waste activated sludge, 80-85% of the copper, 66-69% of the lead, 87% of the zinc, 94-99% of the nickel and 73-83% of the cadmium were leached. The first stage of two-stage anaerobic digestion can thus be optimized as an anaerobic bioleaching process and produce a treated sludge (i.e., digestate) that meets the land-use standards in The Netherlands for copper, zinc, nickel and cadmium, but not for lead.

  1. Storage and degradation of poly-ß-hydroxybutyrate in activated sludge under aerobic conditions

    DEFF Research Database (Denmark)

    Dircks, Klaus; Henze, Mogens; van Loosdrecht, M.C.M.

    2001-01-01

    This research analyses the accumulation and degradation of poly-b-hydroxybutyrate (PHB) in experiments with pulse addition of acetate to samples of activated sludge from pilot-plant and full-scale wastewater treatment plants. The experiments are divided into two periods: a feast period defined...

  2. Oxygen transfer dynamics and activated sludge floc structure under different sludge retention times at low dissolved oxygen concentrations.

    Science.gov (United States)

    Fan, Haitao; Liu, Xiuhong; Wang, Hao; Han, Yunping; Qi, Lu; Wang, Hongchen

    2017-02-01

    In activated sludge systems, the aeration process consumes the most energy. The energy cost can be dramatically reduced by decreasing the operating dissolved oxygen (DO) concentration. However, low DO may lead to incomplete nitrification and poor settling performance of activated sludge flocs (ASFs). This study investigates oxygen transfer dynamics and settling performances of activated sludge under different sludge retention times (SRTs) and DO conditions using microelectrodes and microscopic techniques. Our experimental results showed that with longer SRTs, treatment capacity and settling performances of activated sludge improved due to smaller floc size and less extracellular polymeric substances (EPS). Long-term low DO conditions produced larger flocs and more EPS per unit sludge, which produced a more extensive anoxic area and led to low oxygen diffusion performance in flocs. Long SRTs mitigated the adverse effects of low DO. According to the microelectrode analysis and fractal dimension determination, smaller floc size and less EPS in the long SRT system led to high oxygen diffusion property and more compact floc structure that caused a drop in the sludge volume index (SVI). In summary, our results suggested that long SRTs of activated sludge can improve the operating performance under low DO conditions. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Adsorption mechanisms and the effect of oxytetracycline on activated sludge.

    Science.gov (United States)

    Song, Xiancai; Liu, Dongfang; Zhang, Guowei; Frigon, Matthew; Meng, Xianrong; Li, Kexun

    2014-01-01

    The adsorption mechanisms and the effect of Oxytetracycline (OTC) onto activated sludge were studied. The results show that the adsorption of Oxytetracycline (OTC) onto activated sludge was coincident with the Langmuir, Freundlich and Temkin isotherm models. The Freundlich model had the best fit which suggested that chemical adsorption mechanism was dominant. The influences including pH and metal ions on the OTC were examined. It was demonstrated that the adsorption process was highly pH-dependant, which indicate that cationic exchange mechanisms may play an important role in the adsorption process. Na(+), K(+), Ca(2+), Mg(2+) and Cd(2+) ions more or less inhibited the adsorption of OTC on activated sludge while Cu(2+) enhanced the adsorption ability. The phenomenon may reflect the result that a surface complexation mechanism could involved in the adsorption. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Aerobic storage under dynamic conditions in activated sludge processes

    DEFF Research Database (Denmark)

    Majone, M.; Dircks, K.

    1999-01-01

    In activated sludge processes, several plant configurations (like plug-flow configuration of the aeration tanks, systems with selectors, contact-stabilization processes or SBR processes) impose a concentration gradient of the carbon sources to the biomass. As a consequence, the biomass grows under...... mechanisms can also contribute to substrate removal, depending on the microbial composition and the previous "history" of the biomass. In this paper the type and the extent of this dynamic response is discussed by review of experimental studies on pure cultures, mixed cultures and activated sludges...... and with main reference to its relevance on population dynamics in the activated sludge. Possible conceptual approaches to storage modelling are also presented, including both structured and unstructured modelling. (C) 1999 IAWQ Published by Elsevier Science Ltd. All rights reserved....

  5. A simple empirical model for activated sludge thickening in secondary clarifiers.

    Science.gov (United States)

    Giokas, D L; Kim, Youngchul; Paraskevas, P A; Paleologos, E K; Lekkas, T D

    2002-07-01

    A simple empirical model for the thickening function of the activated sludge secondary clarifiers is presented. The proposed approach relies on the integration of previous models and it is based on the phenomenon of dilution of the incoming activated sludge in the feeding well of the settling tanks. The method provides a satisfactory description of sludge stratification within the clarifier. The only requirements are limited to parameters which are readily incorporated into the routine analysis performed in an activated sludge plant, thereby eliminating the need for additional experimental or computational effort. The method was tested in a full-scale activated sludge plant and it was found that it describes fairly well the return sludge concentration, the diluted sludge blanket concentration, the sludge blanket solids concentration and the sludge blanket height of full-scale secondary clarifiers.

  6. Biodegradability of wastewater and activated sludge organics in anaerobic digestion.

    Science.gov (United States)

    Ikumi, D S; Harding, T H; Ekama, G A

    2014-06-01

    The investigation provides experimental evidence that the unbiodegradable particulate organics fractions of primary sludge and waste activated sludge calculated from activated sludge models remain essentially unbiodegradable in anaerobic digestion. This was tested by feeding the waste activated sludge (WAS) from three different laboratory activated sludge (AS) systems to three separate anaerobic digesters (AD). Two of the AS systems were Modified Ludzack - Ettinger (MLE) nitrification-denitrification (ND) systems and the third was a membrane University of Cape Town (UCT) ND and enhanced biological P removal system. One of the MLE systems and the UCT system were fed the same real settled wastewater. The other MLE system was fed raw wastewater which was made by adding a measured constant flux (gCOD/d) of macerated primary sludge (PS) to the real settled wastewater. This PS was also fed to a fourth AD and a blend of PS and WAS from settled wastewater MLE system was fed to a fifth AD. The five ADs were each operated at five different sludge ages (10-60d). From the measured performance results of the AS systems, the unbiodegradable particulate organic (UPO) COD fractions of the raw and settled wastewaters, the PS and the WAS from the three AS systems were calculated with AS models. These AS model based UPO fractions of the PS and WAS were compared with the UPO fractions calculated from the performance results of the ADs fed these sludges. For the PS, the UPO fraction calculated from the AS and AD models matched closely, i.e. 0.30 and 0.31. Provided the UPO of heterotrophic (OHO, fE_OHO) and phosphorus accumulating (PAO, fE_PAO) biomass were accepted to be those associated with the death regeneration model of organism "decay", the UPO of the WAS calculated from the AS and AD models also matched well - if the steady state AS model fE_OHO = 0.20 and fE_PAO = 0.25 values were used, then the UPO fraction of the WAS calculated from the AS models deviated significantly

  7. Effect of microwave pre-treatment of thickened waste activated sludge on biogas production from co-digestion of organic fraction of municipal solid waste, thickened waste activated sludge and municipal sludge.

    Science.gov (United States)

    Ara, E; Sartaj, M; Kennedy, K

    2014-12-01

    Anaerobic co-digestion of organic fraction of municipal solid waste, with thickened waste activated sludge and primary sludge has the potential to enhance biodegradation of solid waste, increase longevity of existing landfills and lead to more sustainable development by improving waste to energy production. This study reports on mesophilic batch and continuous studies using different concentrations and combinations (ratios) of organic fraction of municipal solid waste, thickened waste activated sludge (microwave pre-treated and untreated) and primary sludge to assess the potential for improved biodegradability and specific biogas production. Improvements in specific biogas production for batch assays, with concomitant improvements in total chemical oxygen demand and volatile solid removal, were obtained with organic fraction of municipal solid waste:thickened waste activated sludge:primary sludge mixtures at a ratio of 50:25:25 (with and without thickened waste activated sludge microwave pre-treatment). This combination was used for continuous digester studies. At 15 d hydraulic retention times, the co-digestion of organic fraction of municipal solid waste:organic fraction of municipal solid waste:primary sludge and organic fraction of municipal solid waste:thickened waste activated sludge microwave:primary sludge resulted in a 1.38- and 1.46-fold increase in biogas production and concomitant waste stabilisation when compared with thickened waste activated sludge:primary sludge (50:50) and thickened waste activated sludge microwave:primary sludge (50:50) digestion at the same hydraulic retention times and volumetric volatile solid loading rate, respectively. The digestion of organic fraction of municipal solid waste with primary sludge and thickened waste activated sludge provides beneficial effects that could be implemented at municipal wastewater treatment plants that are operating at loading rates of less than design capacity.

  8. Reduction by sonication of excess sludge production in a conventional activated sludge system: continuous flow and lab-scale reactor.

    Science.gov (United States)

    Vaxelaire, S; Gonze, E; Merlin, G; Gonthier, Y

    2008-12-01

    Conventional activated sludge wastewater treatment plants currently produce a large quantity of excess sludge. To reduce this sludge production and to improve sludge characteristics in view of their subsequent elimination, an ultrasonic cell disintegration process was studied. In a lab-scale continuous flow pilot plant, part of the return sludge was sonicated by low-frequency and high-powered ultrasound and then recycled to the aeration tank. Two parallel lines were used: one as a control and the other as an assay with ultrasonic treatment. The reactors were continuously fed with synthetic domestic wastewater with a COD (chemical oxygen demand) of approximately 0.5 g l(-) corresponding to a daily load of 0.35-0.50 kg COD kg(-1) TS d(-1). Removal efficiencies (carbon, particles), excess sludge production and sludge characteristics (particle size distribution, mineralization, respiration rate, biological component) were measured every day during the 56-day experiment. This study showed that whilst organic removal efficiency did not deteriorate, excess sludge production was decreased by about 25-30% by an ultrasonic treatment. Several hypotheses are advanced: (i) the treatment made a part of the organic matter soluble as a consequence of the floc disintegration, and optimised the conversion of the carbonaceous pollutants into carbon dioxide and (ii) the treatment modified the physical characteristics of sludge by a mechanical effect: floc size was reduced, increasing the exchange surface and sludge activity. The originality of this study is that experiments were conducted in a continuous-flow activated sludge reactor rather than in a batch reactor.

  9. Evaluating the Measurement of Activated Sludge Foam Potential

    Directory of Open Access Journals (Sweden)

    Eoghan O’Flaherty

    2011-03-01

    Full Text Available The most widely used technique for assessing the propensity of activated sludge to suffer from biological foaming is to measure foam potential. This involves measuring the amount of foam produced from sludge under conditions of controlled aeration. Two approaches have been adopted: (1 Air is passed through specially designed columns from fine porous diffusers at a fixed rate to form uniform sized bubbles or (2 employing Alka-Seltzer™ tablets which effervesce when added to the sludge. Both tests generate foam formation which can then be quantified. Foam assessment in activated sludge is reviewed. A sintered disc aeration column was compared with the Alka-Seltzer™ test method and both methods examined under a range of different environmental conditions. Foam potential measured by the sintered disc method displayed better repeatability compared to the Alka-Seltzer test. The use of a wire cage placed over the tablets greatly improved the precision of the Alka-Seltzer test. A positive linear correlation was also found between foam potential and temperature (4–20 °C. Sludge solids concentration was also shown to influence foaming potential making comparisons between reactors problematic. Recommendations on how to improve the repeatability of foam potential measurements are given.

  10. Nitrate control strategies in an activated sludge wastewater treatment process

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Wenhao; Tao, Erpan; Chen, Xiaoquan; Liu, Dawei [South China University of Technology, Guangzhou (China); Liu, Hongbin [Kyung Hee University, Yongin (Korea, Republic of)

    2014-03-15

    We studied nitrate control strategies in an activated sludge wastewater treatment process (WWTP) based on the activated sludge model. Two control strategies, back propagation for proportional-integral-derivative (BP-PID) and adaptive-network based fuzzy inference systems (ANFIS), are applied in the WWTP. The simulation results show that the simple local constant setpoint control has poor control effects on the nitrate concentration control. However, the ANFIS (4*1) controller, which considers not only the local constant setpoint control of the nitrate concentration, but also three important indices in the effluent--ammonia concentration, total suspended sludge concentration and total nitrogen concentration--demonstrates good control performance. The results also prove that ANFIS (4*1) controller has better control performance than that of the controllers PI, BP-PID and ANFIS (2*1), and that the ANFIS (4*1) controller is effective in improving the effluent quality and maintaining the stability of the effluent quality.

  11. Tracing the evolution of degraders in activated sludge during the sludge’s acclimation to a xenobiotic organic

    Science.gov (United States)

    Chong, N. M.; Fan, C. H.; Yang, Y. C.

    2017-01-01

    The molecular biology method of high-throughput pyrosequencing was employed to examine the change of activated sludge community structures during the process in which activated sludge was acclimated to and degraded a target xenobiotic. The sample xenobiotic organic compound used as the activated sludge acclimation target was the herbicide 2,4-dichlorphenoxyacetic acid (2,4-D). Indigenous activated sludge microorganisms were acclimated to 2,4-D as the sole carbon source in both the batch and the continuous-flow reaction modes. Sludge masses at multiple time points during the course of acclimation were subjected to pyrosequencing targeting the microorganisms’ 16S rRNA genes. With the bacterial 16S rRNA sequencing results the genera that increased in abundance were checked with degradative pathway databases or literature to confirm that they are commonly seen as potent degraders of 2,4-D. From this systematic examination of degrader changes at time points during activated sludge acclimation and degradation of the target xenobiotic, the trend of degrader evolution in activated sludge over the sludge’s acclimation process to a xenobiotic was traced.

  12. IDENTIFICATION AND ECOPHYSIOLOGY OF ACTIVE DENITRIFIERS IN ACTIVATED SLUDGE

    DEFF Research Database (Denmark)

    Hansen, Aviaja Anna; Le-Quy, Vang; Nielsen, Kåre Lehmann

    reactor studies. To obtain better identification of active denitrifying communities in full-scale wastewater treatment plants (WWTPs) we applied DNA-SIP with 13C-labelled substrates, and RT-PCR of expressed denitrification genes (nirS, nirK and nosZ) upon various substrate-inductions. To come around...... the bias of horizontal gene transfer, the identities were verified by microautoradiography (MAR) combined with fluorescence in situ hybridization (FISH) with incorporation of radio-labelled substrates under denitrifying conditions. The in situ abundances of the identified denitrifiers in different WWTPs...... were determined with quantitative FISH, while their active metabolic pathways were investigated directly in activated sludge with a tag-based metatranscriptomic approach under acetate-utilizing and denitrifying conditions. The different methods revealed a majority of denitrifiers in all WWTPs belonging...

  13. Investigation of Excess Sludge Generated from Activated Sludge Treatment Plant of Concentrated Latex Factories: An Investigative Case Study in Southern Thailand

    Directory of Open Access Journals (Sweden)

    Wanrudee Wanseng

    2017-06-01

    Full Text Available Activated sludge technology has been employed for wastewater treatment in the concentrated latex factories in the south of Thailand. This paper highlights the survey results of the excess sludge generated from activated sludge treatment plants of the concentrated latex factories, including sludge generation rate, sludge characteristics, as well as sludge management and its problems. The total number of 11 factories was investigated. The findings showed that 20% of the investigated factories using activated sludge did not know how much the excess sludge generation rate was. With an in-depth investigation, the excess sludge generation rate was determined as for 28 kg/ton concentrated latex product or 10 kg/ton of field latex used in the concentrated latex factories. The excess sludge had a low C/N ratio with an average value of 4.7 and contained N, P, and K with the average of percentage values of 8.0, 2.0, and 1.0% dry basis, respectively. However, the excess sludge consisted of Zn with an average of 3.01% dry basis. 60% of the investigated factories using an activated sludge system had issues concerning the management of excess sludge. Moreover, various aspects of the excess sludge management were discussed and lessons were learned on the current excess sludge management of the concentrated latex industry in the south of Thailand.

  14. Determination of the acute toxicities of physicochemical pretreatment and advanced oxidation processes applied to dairy effluents on activated sludge.

    Science.gov (United States)

    Sivrioğlu, Özge; Yonar, Taner

    2015-04-01

    In this study, the acute toxicities of raw, physicochemical pre-treated, ozonated, and Fenton reagent applied samples of dairy wastewater toward activated sludge microorganisms, evaluated using the International Organization for Standardization's respiration inhibition test (ISO 8192), are presented. Five-day biological oxygen demand (BOD5) was measured to determine the biodegradability of physicochemical treatment, ozonation, Fenton oxidation or no treatment (raw samples) of dairy wastewater. Chemical pretreatment positively affected biodegradability, and the inhibition exhibited by activated sludge was removed to a considerable degree. Ozonation and the Fenton process exhibited good chemical oxygen demand removal (61%) and removal of toxins. Low sludge production was observed for the Fenton process applied to dairy effluents. We did not determine the inhibitory effect of the Fenton-process on the activated sludge mixture. The pollutant-removal efficiencies of the applied processes and their associated operating costs were determined.

  15. Bioremediation of petroleum hydrocarbons in soil: Activated sludge treatability study

    Energy Technology Data Exchange (ETDEWEB)

    Rue-Van Es, J.E. La.

    1993-05-01

    Batch activated sludge treatability studies utilizing petroleum hydrocarbon contaminated soils (diesel oil and leaded gasoline) were conducted to determine: initial indigenous biological activity in hydrocarbon-contaminated soils; limiting factors of microbiological growth by investigating nutrient addition, chemical emulsifiers, and co-substrate; acclimation of indigenous population of microorganisms to utilize hydrocarbons as sole carbon source; and temperature effects. Soil samples were taken from three different contaminated sites and sequencing batch reactors were run. Substrate (diesel fuel) and nutrient were added as determined by laboratory analysis of orthophosphate, ammonia nitrogen, chemical oxygen demand, and total organic carbon. Substrate was made available to the bacterial mass by experimenting with four different chemical emulsifiers. Indigenous microorganisms capable of biotransforming hydrocarbons seem to be present in all the contaminated soil samples received from all sites. Microscopic analysis revealed no visible activity at the beginning of the study and presence of flagellated protozoa, paramecium, rotifers, and nematodes at the end of the year. Nutrient requirements and the limiting factors in microorganism growth were determined for each site. An emulsifier was initially necessary to make the substrate available to the microbial population. Decreases in removal were found with lowered temperature. Removal efficiencies ranged from 50-90%. 95 refs., 11 figs., 13 tabs.

  16. Analysis and modelling of predation on biofilm activated sludge process: Influence on microbial distribution, sludge production and nutrient dosage.

    Science.gov (United States)

    Revilla, Marta; Galán, Berta; Viguri, Javier R

    2016-11-01

    The influence of predation on the biofilm activated sludge (BAS) process is studied using a unified model that incorporates hydrolysis and predation phenomena into the two stages of the BAS system: moving bed biofilm reactor pre-treatment (bacterial-predator stage) and activated sludge (predator stage). The unified model adequately describes the experimental results obtained in a cellulose and viscose full-scale wastewater plant and has been used to evaluate the role and contribution of predator microorganisms towards removal of COD, nutrient requirements, sludge production and microbial distribution. The results indicate that predation is the main factor responsible for the reduction of both nutrient requirements and sludge production. Furthermore, increasing the sludge retention time (SRT) does not influence the total biomass content in the AS reactor of a BAS process in two different industrial wastewater treatments.

  17. Use of Natural Zeolite to Upgrade Activated Sludge Process

    Directory of Open Access Journals (Sweden)

    Hanife Büyükgüngör

    2003-01-01

    Full Text Available The objective of this study was to achieve better efficiency of phosphorus removal in an enhanced biological phosphorus removal process by upgrading the system with different amounts of natural zeolite addition. The system performance for synthetic wastewater containing different carbon sources applied at different initial concentrations of phosphorus, as well as for municipal wastewater, was investigated. Natural zeolite addition in the aerobic phase of the anaerobic/aerobic bioaugmented activated sludge system contributed to a significant improvement of phosphorus removal in systems with synthetic wastewater and fresh municipal wastewater. Improvement of phosphorus removal with regard to the control reactors was higher with the addition of 15 than with 5 g/L of natural zeolite. In reactors with natural zeolite addition with regard to the control reactors significantly decreased chemical oxygen demand, ammonium and nitrate, while higher increment and better-activated sludge settling were achieved, without changes in the pH-values of the medium. It was shown that the natural zeolite particles are suitable support material for the phosphate-accumulating bacteria Acinetobacter calcoaceticus (DSM 1532, which were adsorbed on the particle surface, resulting in increased biological activity of the system. The process of phosphorus removal in a system with bioaugmented activated sludge and natural zeolite addition consisted of: metabolic activity of activated sludge, phosphorus uptake by phosphate-accumulating bacteria adsorbed on the natural zeolite particles and suspended in solution, and phosphorus adsorption on the natural zeolite particles.

  18. Microwave pyrolysis of oily sludge with activated carbon.

    Science.gov (United States)

    Chen, Yi-Rong

    2016-12-01

    The aim of this study is to explore catalytic microwave pyrolysis of crude oil storage tank sludge for fuels using granular activated carbon (GAC) as a catalyst. The effect of GAC loading on the yield of pyrolysis products was also investigated. Heating rate of oily sludge and yield of microwave pyrolysis products such as oil and fuel gas was found to depend on the ratio of GAC to oily sludge. The optimal GAC loading was found to be 10%, while much smaller and larger feed sizes adversely influenced production. During oily sludge pyrolysis, a maximum oil yield of 77.5% was achieved. Pyrolytic oils with high concentrations of diesel oil and gasoline (about 70 wt% in the pyrolytic oil) were obtained. The leaching of heavy metals, such as Cr, As and Pb, was also suppressed in the solid residue after pyrolysis. This technique provides advantages such as harmless treatment of oily sludge and substantial reduction in the consumption of energy, time and cost.

  19. Specific methanogenic activity (SMA of industrial sludge from the aerobic and anaerobic biological treatment

    Directory of Open Access Journals (Sweden)

    Danieli Schneiders

    2013-08-01

    Full Text Available In this study, specific methanogenic activity (SMA tests were performed on textile sludge and food industry sludge. The textile sludge from an activated sludge was collected at the entrance of the secondary biologic clarifier and the food sludge was collected in a UASB reactor. Once collected, the sludges were characterized and tested for SMA. It was found that the microrganisms present in the food sludge had SMA of 0.17 gCOD-CH4 gSSV.d-1 and 337.05 mL of methane production, while the microrganisms of the textile sludge presented 0.10 gCOD-CH4 gSSV.d-1 of SMA and 3.04 mL of methane production. Therefore, the food sludge was more suitable to be used as a starting inoculum in UASB.

  20. Microscopic Analysis of Plankton, Periphyton, and Activated Sludge. Training Manual.

    Science.gov (United States)

    Environmental Protection Agency, Washington, DC. Office of Water Programs.

    This manual is intended for professional personnel in the fields of water pollution control, limnology, water supply and waste treatment. Primary emphasis is given to practice in the identification and enumeration of microscopic organisms which may be encountered in water and activated sludge. Methods for the chemical and instrumental evaluation…

  1. Theoretical and practical aspects of modelling activated sludge processes

    NARCIS (Netherlands)

    Meijer, S.C.F.

    2004-01-01

    This thesis describes the full-scale validation and calibration of a integrated metabolic activated sludge model for biological phosphorus removal. In chapters 1 and 2 the metabolic model is described, in chapters 3 to 6 the model is tested and in chapters 7 and 8 the model is put into practice.

  2. Microscopic Analysis of Plankton, Periphyton, and Activated Sludge. Training Manual.

    Science.gov (United States)

    Environmental Protection Agency, Washington, DC. Office of Water Programs.

    This manual is intended for professional personnel in the fields of water pollution control, limnology, water supply and waste treatment. Primary emphasis is given to practice in the identification and enumeration of microscopic organisms which may be encountered in water and activated sludge. Methods for the chemical and instrumental evaluation…

  3. Theoretical and practical aspects of modelling activated sludge processes

    NARCIS (Netherlands)

    Meijer, S.C.F.

    2004-01-01

    This thesis describes the full-scale validation and calibration of a integrated metabolic activated sludge model for biological phosphorus removal. In chapters 1 and 2 the metabolic model is described, in chapters 3 to 6 the model is tested and in chapters 7 and 8 the model is put into practice. Cha

  4. Theoretical and practical aspects of modelling activated sludge processes

    NARCIS (Netherlands)

    Meijer, S.C.F.

    2004-01-01

    This thesis describes the full-scale validation and calibration of a integrated metabolic activated sludge model for biological phosphorus removal. In chapters 1 and 2 the metabolic model is described, in chapters 3 to 6 the model is tested and in chapters 7 and 8 the model is put into practice. Cha

  5. Aged refuse enhances anaerobic digestion of waste activated sludge.

    Science.gov (United States)

    Zhao, Jianwei; Gui, Lin; Wang, Qilin; Liu, Yiwen; Wang, Dongbo; Ni, Bing-Jie; Li, Xiaoming; Xu, Rui; Zeng, Guangming; Yang, Qi

    2017-10-15

    In this work, a low-cost alternative approach (i.e., adding aged refuse (AR) into waste activated sludge) to significantly enhance anaerobic digestion of sludge was reported. Experimental results showed that with the addition dosage of AR increasing from 0 to 400 mg/g dry sludge soluble chemical oxygen demand (COD) increased from 1150 to 5240 mg/L at the digestion time of 5 d, while the maximal production of volatile fatty acids (VFA) increased from 82.6 to 183.9 mg COD/g volatile suspended solids. Although further increase of AR addition decreased the concentrations of both soluble COD and VFA, their contents in these systems with AR addition at any concentration investigated were still higher than those in the blank, which resulted in higher methane yields in these systems. Mechanism studies revealed that pertinent addition of AR promoted solubilization, hydrolysis, and acidogenesis processes and did not affect methanogenesis significantly. It was found that varieties of enzymes and anaerobes in AR were primary reason for the enhancement of anaerobic digestion. Humic substances in AR benefited hydrolysis and acidogenesis but inhibited methanogenesis. The effect of heavy metals in AR on sludge anaerobic digestion was dosage dependent. Sludge anaerobic digestion was enhanced by appropriate amounts of heavy metals but inhibited by excessive amounts of heavy metals. The relative abundances of microorganisms responsible for sludge hydrolysis and acidogenesis were also observed to be improved in the system with AR addition, which was consistent with the performance of anaerobic digestion. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Thermal hydrolysis of waste activated sludge at Hengelo Wastewater Treatment Plant, the Netherlands.

    Science.gov (United States)

    Oosterhuis, Mathijs; Ringoot, Davy; Hendriks, Alexander; Roeleveld, Paul

    2014-01-01

    The thermal hydrolysis process (THP) is a sludge treatment technique which affects anaerobic biodegradability, viscosity and dewaterability of waste activated sludge (WAS). In 2011 a THP-pilot plant was operated, connected to laboratory-scale digesters, at the water board Regge en Dinkel and in cooperation with Cambi A.S. and MWH Global. Thermal hydrolysis of WAS resulted in a 62% greater volatile solids (VS) reduction compared to non-hydrolysed sludge. Furthermore, the pilot digesters could be operated at a 2.3 times higher solids loading rate compared to conventional sludge digesters. By application of thermal sludge hydrolysis, the overall efficiency of the sludge treatment process can be improved.

  7. Characterization and Leach Testing for PUREX Cladding Waste Sludge (Group 3) and REDOX Cladding Waste Sludge (Group 4) Actual Waste Sample Composites

    Energy Technology Data Exchange (ETDEWEB)

    Snow, Lanee A.; Buck, Edgar C.; Casella, Amanda J.; Crum, Jarrod V.; Daniel, Richard C.; Draper, Kathryn E.; Edwards, Matthew K.; Fiskum, Sandra K.; Jagoda, Lynette K.; Jenson, Evan D.; Kozelisky, Anne E.; MacFarlan, Paul J.; Peterson, Reid A.; Swoboda, Robert G.

    2009-02-13

    A testing program evaluating actual tank waste was developed in response to Task 4 from the M-12 External Flowsheet Review Team (EFRT) issue response plan.(a) The testing program was subdivided into logical increments. The bulk water-insoluble solid wastes that are anticipated to be delivered to the Waste Treatment and Immobilization Plant (WTP) were identified according to type such that the actual waste testing could be targeted to the relevant categories. Eight broad waste groupings were defined. Samples available from the 222S archive were identified and obtained for testing. The actual wastetesting program included homogenizing the samples by group, characterizing the solids and aqueous phases, and performing parametric leaching tests. Two of the eight defined groups—plutonium-uranium extraction (PUREX) cladding waste sludge (Group 3, or CWP) and reduction-oxidation (REDOX) cladding waste sludge (Group 4, or CWR)—are the subjects of this report. Both the Group 3 and 4 waste composites were anticipated to be high in gibbsite, requiring caustic leaching. Characterization of the composite Group 3 and Group 4 waste samples confirmed them to be high in gibbsite. The focus of the Group 3 and 4 testing was on determining the behavior of gibbsite during caustic leaching. The waste-type definition, archived sample conditions, homogenization activities, characterization (physical, chemical, radioisotope, and crystal habit), and caustic leaching behavior as functions of time, temperature, and hydroxide concentration are discussed in this report. Testing was conducted according to TP-RPP-WTP-467.

  8. Carbon dioxide adsorption in chemically activated carbon from sewage sludge.

    Science.gov (United States)

    de Andrés, Juan Manuel; Orjales, Luis; Narros, Adolfo; de la Fuente, María del Mar; Encarnación Rodríguez, María

    2013-05-01

    In this work, sewage sludge was used as precursor in the production of activated carbon by means of chemical activation with KOH and NaOH. The sludge-based activated carbons were investigated for their gaseous adsorption characteristics using CO2 as adsorbate. Although both chemicals were effective in the development of the adsorption capacity, the best results were obtained with solid NaOH (SBA(T16)). Adsorption results were modeled according to the Langmuir and Freundlich models, with resulting CO2 adsorption capacities about 56 mg/g. The SBA(T16) was characterized for its surface and pore characteristics using continuous volumetric nitrogen gas adsorption and mercury porosimetry. The results informed about the mesoporous character of the SBA(T16) (average pore diameter of 56.5 angstroms). The Brunauer-Emmett-Teller (BET) surface area of the SBA(T16) was low (179 m2/g) in comparison with a commercial activated carbon (Airpel 10; 1020 m2/g) and was mainly composed of mesopores and macropores. On the other hand, the SBA(T16) adsorption capacity was higher than that of Airpel 10, which can be explained by the formation of basic surface sites in the SBA(T16) where CO2 experienced chemisorption. According to these results, it can be concluded that the use of sewage-sludge-based activated carbons is a promising option for the capture of CO2. Adsorption methods are one of the current ways to reduce CO2 emissions. Taking this into account, sewage-sludge-based activated carbons were produced to study their CO2 adsorption capacity. Specifically, chemical activation with KOH and NaOH of previously pyrolyzed sewage sludge was carried out. The results obtained show that even with a low BET surface area, the adsorption capacity of these materials was comparable to that of a commercial activated carbon. As a consequence, the use of sewage-sludge-based activated carbons is a promising option for the capture of CO2 and an interesting application for this waste.

  9. Influence of magnetic field on activity of given anaerobic sludge.

    Science.gov (United States)

    Xu, Y B; Duan, X J; Yan, J N; Du, Y Y; Sun, S Y

    2009-11-01

    Two modes of magnetic fields were applied in the Cr(6+) removal sludge reactors containing two predominated strains--Bacillus sp. and Brevibacillus sp., respectively. The magnetic field mode I* of 0-4.5 or 0-14 mT between pieces was obtained by setting the magnetic pieces with the surface magnetic density of 0-6 or 0-20 mT into the reactor, and the magnetic field mode II* of 6, 20, or 40 mT on the return line was obtained by controlling the working distance of the permanent magnet outside the sludge return line. The effects of different magnetic fields on the activity of the given anaerobic sludge were studied by comparing with the control (absent of magnetic field). The results showed that the magnetic field of 0-4 mT improved the activity of given sludge most effectively, U(max) CH(4) (the peak methane-producing rate) and the methane producing volume per gCOD(Cr) reached 64.3 mlCH(4)/gVSS.d and 124 mlCH(4)/gCOD(Cr), which increased by 20.6 and 70.7%, respectively, compared with the control. And the magnetic field of 20 mT took second place. It could be concluded that the input of some magnetic field could improve the activity of anaerobic sludge by increasing the transformation efficiency of COD(Cr) matters to methane, and the total organic wastage did not increase.

  10. The efficiency of different phenol-degrading bacteria and activated sludges in detoxification of phenolic leachates.

    Science.gov (United States)

    Kahru, A; Reiman, R; Rätsep, A

    1998-07-01

    Phenolic composition, toxicity and biodegradability of three different phenolic leachates/samples was studied. Samples A and C were the leachates from the oil-shale industry spent shale dumps at Kohtla-Järve, Estonia. Sample B was a laboratory-prepared synthetic mixture of 7 phenolic compounds mimmicking the phenolic composition of the leachate A. Toxicity of these 3 samples was analyzed using two photobacterial test (BioTox and Microtox), Daphnia test (DAPHTOXKIT F pulex) and rotifiers' test (ROTOXKIT F). All the LC50 values were in the range of 1-10%, leachate A being the most toxic. The growth and detoxifying potential (toxicity of the growth medium was measured using photobacterial tests) of 3 different phenol-utilizing bacteria and acclimated activated sludges was studied in shake-flask cultures. 30% leachate A (altogether 0.6 mM total phenolic compounds) was too toxic to rhodococci and they did not grow. Cell number of Kurthia sp. and Pseudomonas sp. in 30% leachate A increased by 2 orders of magnitude but despite of the growth of bacteria the toxicity of the leachate did not decrease even by 7 weeks of cultivation. However, if the activated sludge was used instead of pure bacterial cultures the toxicity of the 30% leachate A was eliminated already after 3 days of incubation. 30% samples B and C were detoxified by activated sludge even more rapidly, within 2 days. As the biodegradable part of samples A and B should be identical, the detoxification of leachate A compared to that of sample B was most probably inhibited by inorganic (e.g. sulphuric) compounds present in the leachate A. Also, the presence of toxic recalcitrant organic compounds in the leachate A (missed by chemical analysis) that were not readily biodegradable even by activated sludge consortium should not be excluded.

  11. Effects of TiO2 and Ag nanoparticles on polyhydroxybutyrate biosynthesis by activated sludge bacteria.

    Science.gov (United States)

    Priester, John H; Van De Werfhorst, Laurie C; Ge, Yuan; Adeleye, Adeyemi S; Tomar, Shivira; Tom, Lauren M; Piceno, Yvette M; Andersen, Gary L; Holden, Patricia A

    2014-12-16

    Manufactured nanomaterials (MNMs) are increasingly incorporated into consumer products that are disposed into sewage. In wastewater treatment, MNMs adsorb to activated sludge biomass where they may impact biological wastewater treatment performance, including nutrient removal. Here, we studied MNM effects on bacterial polyhydroxyalkanoate (PHA), specifically polyhydroxybutyrate (PHB), biosynthesis because of its importance to enhanced biological phosphorus (P) removal (EBPR). Activated sludge was sampled from an anoxic selector of a municipal wastewater treatment plant (WWTP), and PHB-containing bacteria were concentrated by density gradient centrifugation. After starvation to decrease intracellular PHB stores, bacteria were nutritionally augmented to promote PHB biosynthesis while being exposed to either MNMs (TiO2 or Ag) or to Ag salts (each at a concentration of 5 mg L(-1)). Cellular PHB concentration and PhyloChip community composition were analyzed. The final bacterial community composition differed from activated sludge, demonstrating that laboratory enrichment was selective. Still, PHB was synthesized to near-activated sludge levels. Ag salts altered final bacterial communities, although MNMs did not. PHB biosynthesis was diminished with Ag (salt or MNMs), indicating the potential for Ag-MNMs to physiologically impact EBPR through the effects of dissolved Ag ions on PHB producers.

  12. Substrate utilization and VSS relations in activated sludge processes

    Energy Technology Data Exchange (ETDEWEB)

    Droste, R.L.; Fernandes, L.; Sun, X. [Ottawa Univ., ON (Canada). Dept. of Civil Engineering

    1993-12-31

    A new empirical substrate removal model for activated sludge in continuous flow stirred tank reactor (CFSTR) and sequencing batch reactor (SBR) was developed in this study. This model includes an exponential function of volatile suspended solids to express the active biomass which is actually involved in substrate utilization. Results indicate that the proposed exponential models predict more accurately effluent COD in CFSTR and SBR systems than the first or zero order models. (author). 7 refs., 1 fig., 4 tabs.

  13. Enhanced Lipid and Biodiesel Production from Glucose-Fed Activated Sludge: Kinetics an Microbial Community Analysis

    Science.gov (United States)

    An innovative approach to increase biofuel feedstock lipid yields from municipal sewage sludge via manipulation of carbon:nitrogen (C:N) ratio and glucose loading in activated sludge bioreactors was investigated. Sludge lipid and fatty acid methyl ester (biodiesel) yields (% cel...

  14. Presence of Naturally Occurring Radioactive Materials in sludge samples from several Spanish water treatment plants

    Energy Technology Data Exchange (ETDEWEB)

    Palomo, M.; Penalver, A.; Aguilar, C. [Unitat de Radioquimica Ambiental i Sanitaria, Universitat Rovira i Virgili, Consorci d' Aigues de Tarragona (CAT), Ctra. Nacional 340 Km. 1094, Ap. correus n.7, 43895 L' Ampolla, Tarragona (Spain); Borrull, F., E-mail: francesc.borrull@urv.cat [Unitat de Radioquimica Ambiental i Sanitaria, Universitat Rovira i Virgili, Consorci d' Aigues de Tarragona (CAT), Ctra. Nacional 340 Km. 1094, Ap. correus n.7, 43895 L' Ampolla, Tarragona (Spain)

    2010-09-15

    Sludge samples from eleven potable water treatment plants (PWTP), three waste water treatment plants (WWTP) and an industrial water treatment plant (IWTP), located in different areas of Spain, mainly in Catalonia, were analyzed for their radiological content in order to determine whether they could be considered as industries affected by naturally occurring radioactive material (NORM). In general, samples from the PWTPs showed higher activity values for the alpha and gamma emitting isotopes than the WWTPs and the IWTP. For example, samples from the area located in the north of Catalonia show values of {sup 234}U, {sup 235}U and {sup 238}U in the range of 84.4-792.1 Bq/kg, 3.3-26.8 Bq/kg and 63.8-585.9 Bq/kg, respectively. In general, for PWTP, the values obtained for the gamma emitter and alpha emitter isotopes showed that both the geology and the industrial activities correlate with the values measured. The magnitude of these results demonstrates the need to measure the radionuclide content of these samples before reaching a decision about their final disposal.

  15. Electrochemical pretreatment of waste activated sludge: effect of process conditions on sludge disintegration degree and methane production.

    Science.gov (United States)

    Ye, Caihong; Yuan, Haiping; Dai, Xiaohu; Lou, Ziyang; Zhu, Nanwen

    2016-11-01

    Waste activated sludge (WAS) requires a long digestion time because of a rate-limiting hydrolysis step - the first phase of anaerobic digestion (AD). Pretreatment can be used prior to AD to facilitate the hydrolysis step and improve the efficiency of WAS digestion. This study evaluated a novel application of electrochemical (EC) technology employed as the pretreatment method prior to AD of WAS, focusing on the effect of process conditions on sludge disintegration and subsequent AD process. A superior process condition of EC pretreatment was obtained by reaction time of 30 min, electrolysis voltage of 20 V, and electrode distance of 5 cm, under which the disintegration degree of WAS ranged between 9.02% and 9.72%. In the subsequent batch AD tests, 206 mL/g volatile solid (VS) methane production in EC pretreated sludge was obtained, which was 20.47% higher than that of unpretreated sludge. The AD time was 19 days shorter for EC pretreated sludge compared to the unpretreated sludge. Additionally, the EC + AD reactor achieved 41.84% of VS removal at the end of AD. The analysis of energy consumption showed that EC pretreatment could be effective in enhancing sludge AD with reduced energy consumption when compared to other pretreatment methods.

  16. Characterization of the fate of lipids in activated sludge

    Institute of Scientific and Technical Information of China (English)

    Kangala B.Chipasa; Krystyna Medrzycka

    2008-01-01

    Experiments were carried out to characterize the transformation of lipids in activated sludge under aerobic conditions. Results showed that the overall lipid content in the effluent could not be reduced to values below 300 mg/L from an initial content of 2, 000 mg/L. However, the contents of individual fatty acids underwent drastic decreases and increases during all microbial growth phases. These changes in contents of individual fatty acids showed that fatty acids were used as substrates by microorganisms as well as released into the wastewater as by-products. We have therefore suggested a novel model of transformation of lipids in activated sludge, showing that utilization of microbial activity for complete removal of lipids from wastewater is limited.

  17. Toxicity formation and distribution in activated sludge during treatment of N,N-dimethylformamide (DMF) wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Na; Chen, Xiurong, E-mail: xrchen@ecust.edu.cn; Lin, Fengkai; Ding, Yi; Zhao, Jianguo; Chen, Shanjia

    2014-01-15

    Highlights: • We studied mechanism of sludge organic toxicity formation in wastewater treatment. • The organic toxicity distributed mainly in the inner section of sludge flocs. • The organic toxicity of sludge increased with DMF initial concentrations increments. • The property of bacteria community correlates significantly with sludge toxicity. -- Abstract: The organic toxicity of sludge in land applications is a critical issue; however, minimal attention has been given to the mechanism of toxicity formation during high-strength wastewater treatment. To investigate the relevant factors that contribute to sludge toxicity, synthetic wastewater with N,N-dimethylformamide (DMF) was treated in a sequential aerobic activated sludge reactor. The acute toxicity of sludge, which is characterised by the inhibition rate of luminous bacteria T3, is the focus of this study. Using an operational time of 28 days and a hydraulic retention time of 12 h, the study demonstrated a positive relationship between the acute toxicity of sludge and the influent DMF concentration; the toxicity centralised in the intracellular and inner sections of extracellular polymeric substances (EPS) in sludge flocs. Due to increased concentrations of DMF, which ranged from 40 to 200 mg L{sup −1}, the sludge toxicity increased from 25 to 45%. The organic toxicity in sludge flocs was primarily contributed by the biodegradation of DMF rather than adsorption of DMF. Additional investigation revealed a significant correlation between the properties of the bacterial community and sludge toxicity.

  18. Radiochemistry determination of activity concentration of {sup 210}Pb in sludge and scale samples of UN-SEAL PETROBRAS, Sergipe; Determinacao radioquimica das concentracoes de atividade de {sup 210}Pb em amostras de borras e incrustacoes da UN-SEAL PETROBRAS, Sergipe

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, Andressa A. de; Hazin, Clovis A. [Pernambuco Univ., Recife, PE (Brazil). Dept. de Energia Nuclear]. E-mail: andressa.arruda@globo.com; hazin@ufpe.br; Valentim, Eliane [Centro Regional de Ciencias Nucleares (CRCN), Recife, PE (Brazil)]. E-mail: valentim@cnen.gov.br

    2005-07-01

    The presence of radionuclides of the {sup 238}U and {sup 232}Th series in sludge and scales generated inactivities of oil E and P is a well known phenomenon. Scales formed in the inner surface of ducts are constituted basically of CaCO{sub 3} and BaSO{sub 4} precipitates, being responsible for the gradual reduction in oil production. Sludge, on the other hand, is a mixture of solid debris (sand and rust particles) and oil that accumulate in the bottom of vessels (storage tanks and separators) normally in the form of sulfate and carbonate deposits. The most important radionuclides normally found in sludge and scale are {sup 226}Ra, {sup 228}Ra, {sup 210}Pb and {sup 228}Th. The presence of these radionuclides may cause a significant dose to workers, with the consequent increase in the risk of stochastic effects. A program of studies aiming to determine the activity concentration of radionuclides of the two above mentioned series in scales and sludge samples collected in an E and P unit of PETROBRAS in the State of Sergipe (UN-SEAL), is under way in the Department of Nuclear Energy of the Federal University of Pernambuco (DEN/UFPE). The analyses already carried through by gamma spectrometry had indicated the existence of high concentrations of radium, showing the necessity of extending the survey for other elements of the {sup 238}U series. This work, therefore, aims to determine the activity concentrations of {sup 210}Pb through radiochemical analysis, as well as, to evaluate some available techniques for the determination of {sup 210}Pb in the above-mentioned matrix. (author)

  19. Characterization of the tank 51 alternate reductant sludge batch 9 slurry sample (HTF-51-15-130)

    Energy Technology Data Exchange (ETDEWEB)

    Reboul, S. H. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-02-01

    Tank 51 slurry sample HTF-51-15-130 was collected following sludge washing at the Tank Farm. The sample was received at SRNL and then characterized in preparation for qualification of the alternate reductant Sludge Batch 9 (SB9) flowsheet. In this characterization, densities, solids distribution, elemental constituents, anionic constituents, carbon content, and select radioisotopes were quantified.

  20. Diversity of Dominant Bacterial Taxa in Activated Sludge Promotes Functional Resistance following Toxic Shock Loading

    KAUST Repository

    Saikaly, Pascal

    2010-12-14

    Examining the relationship between biodiversity and functional stability (resistance and resilience) of activated sludge bacterial communities following disturbance is an important first step towards developing strategies for the design of robust biological wastewater treatment systems. This study investigates the relationship between functional resistance and biodiversity of dominant bacterial taxa by subjecting activated sludge samples, with different levels of biodiversity, to toxic shock loading with cupric sulfate (Cu[II]), 3,5-dichlorophenol (3,5-DCP), or 4-nitrophenol (4-NP). Respirometric batch experiments were performed to determine the functional resistance of activated sludge bacterial community to the three toxicants. Functional resistance was estimated as the 30 min IC50 or the concentration of toxicant that results in a 50% reduction in oxygen utilization rate compared to a referential state represented by a control receiving no toxicant. Biodiversity of dominant bacterial taxa was assessed using polymerase chain reaction-terminal restriction fragment length polymorphism (PCR-T-RFLP) targeting the 16S ribosomal RNA (16S rRNA) gene. Statistical analysis of 30 min IC50 values and PCR-T-RFLP data showed a significant positive correlation (P<0.05) between functional resistance and microbial diversity for each of the three toxicants tested. To our knowledge, this is the first study showing a positive correlation between biodiversity of dominant bacterial taxa in activated sludge and functional resistance. In this system, activated sludge bacterial communities with higher biodiversity are functionally more resistant to disturbance caused by toxic shock loading. © 2010 Springer Science+Business Media, LLC.

  1. Metaproteomics: Evaluation of protein extraction from activated sludge.

    Science.gov (United States)

    Hansen, Susan Hove; Stensballe, Allan; Nielsen, Per Halkjaer; Herbst, Florian-Alexander

    2014-11-01

    Metaproteomic studies of full-scale activated sludge systems require reproducible protein extraction methods. A systematic evaluation of three different extractions protocols, each in combination with three different methods of cell lysis, and a commercial kit were evaluated. Criteria used for comparison of each method included the extracted protein concentration and the number of identified proteins and peptides as well as their phylogenetic, cell localization and functional distribution and quantitative reproducibility. Furthermore, the advantage of using specific metagenomes and a 2-step database approach was illustrated. The results recommend a protocol for protein extraction from activated sludge based on the protein extraction reagent B-Per and bead beating. The data have been deposited to the ProteomeXchange with identifier PXD000862 (http://proteomecentral.proteomexchange.org/dataset/PXD000862).

  2. Activated sewage sludge, a potential animal foodstuff: Parts I and II

    Energy Technology Data Exchange (ETDEWEB)

    Bacon, A.G.J.; Ferns, P.N.

    1979-08-01

    Described are experiments that evaluated the mineral content and nutritive value of activated sludge single-cell protein (ASCP) samples as potential animal feedstuffs. Samples were collected at bi-weekly intervals from rural domestic sludge works for one year. Determined for each sample were annual ranges and values of moisture; fat; total nitrogen; crude protein; Lowry protein; fiber; saponification value; carbohydrates available as glucose; ash; and 26 elements. ASCP was shown to possess a nutritive value equivalent to that of brewers yeast and proved to be a good source of B12 vitamins. However, high treatment costs and public prejudice operate against the acceptance of the use of ASCP as an animal feedstuff. (16 graphs, 52 references, 7 tables)

  3. ANALYSIS OF DWPF SLUDGE BATCH 6 (MACROBATCH 7) POUR STREAM GLASS SAMPLES

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, F.

    2012-01-20

    The Defense Waste Processing Facility (DWPF) began processing Sludge Batch 6 (SB6), also referred to as Macrobatch 7 (MB7), in June 2010. SB6 is a blend of the heel of Tank 40 from Sludge Batch 5 (SB5), H-Canyon Np transfers and SB6 that was transferred to Tank 40 from Tank 51.1 SB6 was processed using Frit 418. Sludge is received into the DWPF Chemical Processing Cell (CPC) and is processed through the Sludge Receipt and Adjustment Tank (SRAT) and Slurry Mix Evaporator Tank (SME). The treated sludge slurry is then transferred to the Melter Feed Tank (MFT) and fed to the melter. During processing of each sludge batch, the DWPF is required to take at least one glass sample to meet the objectives of the Glass Product Control Program (GPCP) and to complete the necessary Production Records so that the final glass product may be disposed of at a Federal Repository. The DWPF requested various analyses of radioactive glass samples obtained from the melter pour stream during processing of SB6 as well as reduction/oxidation (REDOX) analysis of MFT samples to determine the impact of Argon bubbling. Sample analysis followed the Task Technical and Quality Assurance Plan (TTQAP) and an Analytical Study Plan (ASP). Four Pour Stream (PS) glass samples and two MFT slurry samples were delivered to the Savannah River National Laboratory (SRNL) from the DWPF. Table 1-1 lists the sample information for each pour stream glass sample. SB6 PS3 (S03472) was selected as the official pour stream sample for SB6 and full analysis was requested. This report details the visual observations of the as-received SB6 PS No.3 glass sample as well as results for the chemical composition, Product Consistency Test (PCT), radionuclide content, noble metals, and glass density. REDOX results will be provided for all four pour stream samples and vitrified samples of MFT-558 and MFT-568A. Where appropriate, data from other pour stream samples will be provided.

  4. Activated sludge process based on artificial neural network

    Institute of Scientific and Technical Information of China (English)

    张文艺; 蔡建安

    2002-01-01

    Considering the difficulty of creating water quality model for activated sludge system, a typical BP artificial neural network model has been established to simulate the operation of a waste water treatment facilities. The comparison of prediction results with the on-spot measurements shows the model, the model is accurate and this model can also be used to realize intelligentized on-line control of the wastewater processing process.

  5. ELIMINATION OF THE CHARACTERIZATION OF DWPF POUR STREAM SAMPLE AND THE GLASS FABRICATION AND TESTING OF THE DWPF SLUDGE BATCH QUALIFICATION SAMPLE

    Energy Technology Data Exchange (ETDEWEB)

    Amoroso, J.; Peeler, D.; Edwards, T.

    2012-05-11

    A recommendation to eliminate all characterization of pour stream glass samples and the glass fabrication and Product Consistency Test (PCT) of the sludge batch qualification sample was made by a Six-Sigma team chartered to eliminate non-value-added activities for the Defense Waste Processing Facility (DWPF) sludge batch qualification program and is documented in the report SS-PIP-2006-00030. That recommendation was supported through a technical data review by the Savannah River National Laboratory (SRNL) and is documented in the memorandums SRNL-PSE-2007-00079 and SRNL-PSE-2007-00080. At the time of writing those memorandums, the DWPF was processing sludge-only waste but, has since transitioned to a coupled operation (sludge and salt). The SRNL was recently tasked to perform a similar data review relevant to coupled operations and re-evaluate the previous recommendations. This report evaluates the validity of eliminating the characterization of pour stream glass samples and the glass fabrication and Product Consistency Test (PCT) of the sludge batch qualification samples based on sludge-only and coupled operations. The pour stream sample has confirmed the DWPF's ability to produce an acceptable waste form from Slurry Mix Evaporator (SME) blending and product composition/durability predictions for the previous sixteen years but, ultimately the pour stream analysis has added minimal value to the DWPF's waste qualification strategy. Similarly, the information gained from the glass fabrication and PCT of the sludge batch qualification sample was determined to add minimal value to the waste qualification strategy since that sample is routinely not representative of the waste composition ultimately processed at the DWPF due to blending and salt processing considerations. Moreover, the qualification process has repeatedly confirmed minimal differences in glass behavior from actual radioactive waste to glasses fabricated from simulants or batch chemicals. In

  6. Wet oxidation of activated sludge: transformations and mechanisms.

    Science.gov (United States)

    Urrea, José Luis; Collado, Sergio; Laca, Amanda; Díaz, Mario

    2014-12-15

    Wet oxidation (WO) is an interesting alternative for the solubilization and mineralization of activated sludge. The effects of different temperatures (160-200 °C) and pressures (4-8 MPa), on the evolution of chemical composition and rheological characteristics of a thickened activated sludge during WO are analyzed in this work. Soluble COD increases initially to a maximum and then diminishes, while the apparent viscosity of the mixture falls continuously throughout the experiment. Based on the experimental evolution of the compositions and rheological characteristics of the sludge, a mechanism consisting of two stages in series is proposed. Initially, the solid organic compounds are solubilized following a pseudo-second order kinetic model with respect to solid COD. After that, the solubilized COD was oxidized, showing a pseudofirst kinetic order, by two parallel pathways: the complete mineralization of the organic matter and the formation of highly refractory COD. Kinetic parameters of the model, including the activation energies are mentioned, with good global fitting to the experiments described.

  7. Biodegradation and adsorption of antibiotics in the activated sludge process.

    Science.gov (United States)

    Li, Bing; Zhang, Tong

    2010-05-01

    The removal of 11 antibiotics of 6 classes, that is, two beta-lactams (ampicillin and cefalexin), two sulfonamides (sulfamethoxazole and sulfadiazine), three fluoroquinolones (norfloxacin, ofloxacin, and ciprofloxacin), one tetracyclines (tetracycline), two macorlides (roxithromycin and anhydro-erythromycin), and one others (trimethoprim), in activated sludge process was investigated using two series of batch reactors treating freshwater and saline sewage respectively. At environmental relevant concentrations tested in this study, biodegradation and adsorption were the major removal routes for the target antibiotics, where volatilization and hydrolysis were neglectable. Among the 11 target antibiotics, cefalexin and the two sulfonamides were predominantly removed by biodegradation in both freshwater and saline sewage systems. Ampicillin, norfloxacin, ciprofloxacin, ofloxacin, tetracycline, roxithromycin, and trimethoprim were mainly removed by adsorption. Divalent cations (Ca(2+) and Mg(2+)) in saline sewage significantly decreased the adsorption of the three fluoroquinolones onto activated sludge. These three fluoroquinolones also exhibited certain biodegradability in the saline activated sludge reactor. Erythromycin-H(2)O was persistent in both saline and freshwater systems under the experimental conditions and could not be removed at all. Kinetics study showed that biodegradation of cefalexin, the two sulfonamides and the three fluoroquinolones followed first-order model well (R(2): 0.921-0.997) with the rate constants ranging from 5.2 x 10(-3) to 3.6 x 10(-1) h(-1).

  8. Rapid determination of filamentous microorganisms in activated sludge; Determinacion rapida de microorganismos filamentosos en fangos activados

    Energy Technology Data Exchange (ETDEWEB)

    Arnaiz, C.; Jimenez, C.; Estevez, F. [Empresa Municipal de Abastecimiento y Saneamiento de Aguas de Sevilla (Spain)

    1999-07-01

    Despite many methods available biomass estimation of a bioprocess may sometimes become laborious and impracticable. Samples containing filamentous organisms, as in Wastewater Treatment Plants, present special counting difficulties. If they are abundant they may need to be estimated separately. In this work a counting method for these organisms is show. The main goal is to improve chlorination of activated sludge suffering bulking or foaming through a quantitative record of filamentous bacteria. (Author) 12 refs.

  9. RESPIROMETRIC ACTIVITY OF ACTIVATED SLUDGE AND BIOFILM IN IFAS-MBBR SYSTEM

    Directory of Open Access Journals (Sweden)

    Paula Piechna

    2017-07-01

    Full Text Available The aim of the presented study was: a assessment of activity of microorganisms developed in form of activated sludge and biofilm, b indirect assessment of the role of analyzed biocoenoses in removal of organic compounds in hybrid reactor with moving bed. Oxygen uptake rate tests (OUR have been used, and obtained results were presented as volumetric activity (expressed in mg O2/L · h and mass activity (expressed as mg O2/g VTS · h. Tests were conducted for three different variants, in which, as the biomass: 1 biofilm was used, 2 activated sludge was used, 3 biofilm and activated sludge were used. The biomass was collected from aerobic reactor from a wastewater treatment plant working in IFAS-MBBR system. The highest volumetric activity was observed for variant with biofilm and activated sludge, and the lowest for variant with biofilm only. Nonetheless, the highest value of oxygen uptake rate related to total volatile solids was observed for variant with biofilm and the lowest for activated sludge. Obtained results suggest, that during this research, at the wastewater treatment plant, the main role in removal of organic pollutants played the biomass developed in form of activated sludge.

  10. Preparation of activated carbon from wet sludge by electrochemical-NaClO activation.

    Science.gov (United States)

    Miao, Chen; Ye, Caihong; Zhu, Tianxing; Lou, Ziyang; Yuan, Haiping; Zhu, Nanwen

    2014-01-01

    Activated carbon (AC) from sludge is one potential solution for sewage sludge disposal, while the drying sludge is cost and time consuming for preparation. AC preparation from the wet sludge with electrochemical-NaClO activation was studied in this work. Three pretreatment processes, i.e. chemical activation, electrolysis and electrochemical-reagent reaction, were introduced to improve the sludge-derived AC properties, and the optimum dosage of reagent was tested from the 0.1:1 to 1:1 (mass rate, reagent:dried sludge). It was shown that the electrochemical-NaClO preparation is the best method under the test conditions, in which AC has the maximum Brunauer, Emmett and Teller area of 436 m²/g at a mass ratio of 0.7. Extracellular polymeric substances in sludge can be disintegrated by electrochemical-NaClO pretreatment, with a disintegration degree of more than 45%. The percentage of carbon decreased from 34.16 to 8.81 after treated by electrochemical-NaClO activation. Fourier transform infrared spectra showed that a strong C-Cl stretching was formed in electrochemical-NaClO prepared AC. The maximum adsorption capacity of AC reaches 109 mg/g on MB adsorption experiment at pH 10 and can be repeated for three times with high removal efficiency after regeneration.

  11. Micropollutant degradation via extracted native enzymes from activated sludge.

    Science.gov (United States)

    Krah, Daniel; Ghattas, Ann-Kathrin; Wick, Arne; Bröder, Kathrin; Ternes, Thomas A

    2016-05-15

    A procedure was developed to assess the biodegradation of micropollutants in cell-free lysates produced from activated sludge of a municipal wastewater treatment plant (WWTP). This proof-of-principle provides the basis for further investigations of micropollutant biodegradation via native enzymes in a solution of reduced complexity, facilitating downstream protein analysis. Differently produced lysates, containing a variety of native enzymes, showed significant enzymatic activities of acid phosphatase, β-galactosidase and β-glucuronidase in conventional colorimetric enzyme assays, whereas heat-deactivated controls did not. To determine the enzymatic activity towards micropollutants, 20 compounds were spiked to the cell-free lysates under aerobic conditions and were monitored via LC-ESI-MS/MS. The micropollutants were selected to span a wide range of different biodegradabilities in conventional activated sludge treatment via distinct primary degradation reactions. Of the 20 spiked micropollutants, 18 could be degraded by intact sludge under assay conditions, while six showed reproducible degradation in the lysates compared to the heat-deactivated negative controls: acetaminophen, N-acetyl-sulfamethoxazole (acetyl-SMX), atenolol, bezafibrate, erythromycin and 10,11-dihydro-10-hydroxycarbamazepine (10-OH-CBZ). The primary biotransformation of the first four compounds can be attributed to amide hydrolysis. However, the observed biotransformations in the lysates were differently influenced by experimental parameters such as sludge pre-treatment and the addition of ammonium sulfate or peptidase inhibitors, suggesting that different hydrolase enzymes were involved in the primary degradation, among them possibly peptidases. Furthermore, the transformation of 10-OH-CBZ to 9-CA-ADIN was caused by a biologically-mediated oxidation, which indicates that in addition to hydrolases further enzyme classes (probably oxidoreductases) are present in the native lysates. Although the

  12. Ubiquity of activated sludge ferricyanide-mediated BOD methods: a comparison of sludge seeds across wastewater treatment plants.

    Science.gov (United States)

    Jordan, Mark A; Welsh, David T; Teasdale, Peter R

    2014-07-01

    Many studies have described alternatives to the BOD5 standard method, with substantial decreases in incubation time observed. However, most of these have not maintained the features that make the BOD5 assay so relevant - a high level of substrate bio-oxidation and use of wastewater treatment plant (WWTP) sludge as the biocatalyst. Two recently described ferricyanide-mediated (FM)-BOD assays, one for trade wastes and one for WWTP influents and treated effluents, satisfy these criteria and were investigated further here for their suitability for use with diverse biocatalysts. Both FM-BOD assays responded proportionately to increasing substrate concentration with sludges from 11 different WWTPs and temporally (months to years) using sludges from a single WWTP, confirming the broad applicability of both assays. Sludges from four WWTPs were selected as biocatalysts for each FM-BOD assay to compare FM-BOD equivalent values with BOD5 (three different sludge seeds) measurements for 12 real wastewater samples (six per assay). Strong and significant relationships were established for both FM-BOD assays. This study has demonstrated that sludge sourced from many WWTPs may be used as the biocatalyst in either FM-BOD assay, as it is in the BOD5 assay. The industry potential of these findings is substantial given the widespread use of the BOD5 assay, the dramatically decreased incubation period (3-6h) and the superior analytical range of both assays compared to the standard BOD5 assay.

  13. Bioproducts for Sludge Reduction in Activated Sludge Systems Treating Oil Refinery Wastewater

    Directory of Open Access Journals (Sweden)

    Alexandre V.M.F.

    2016-03-01

    Full Text Available The use of bioproducts that change the cellular metabolism and reduce microbial growth without affecting the organic matter removal is very promising for reducing the amount of sludge in wastewater treatment systems. In this study, two bioproducts were evaluated and compared with a well-known chemical (2,4-DiNitroPhenol – DNP in activated sludge treating petroleum refinery wastewater. In batch experiments, 10 mg/L of DNP, 0.8 mg/L of a bioproduct based on Folic Acid (FA and 10 mg/L of a bioproduct based on Stress Proteins (SP led to 30.6%, 43.2% and 29.8% lower disposal of total solids, respectively. Operating on a continuous regimen, the addition of 10 mg/L of the bioproduct based on SP led to 45.7% lower disposal for 50 days. In all cases, no loss of efficiency in the Chemical Oxygen Demand (COD removal was observed.

  14. Can activated sludge treatments and advanced oxidation processes remove organophosphorus flame retardants?

    Science.gov (United States)

    Cristale, Joyce; Ramos, Dayana D; Dantas, Renato F; Machulek Junior, Amilcar; Lacorte, Silvia; Sans, Carme; Esplugas, Santiago

    2016-01-01

    This study aims to determine the occurrence of 10 OPFRs (including chlorinated, nonchlorinated alkyl and aryl compounds) in influent, effluent wastewaters and partitioning into sludge of 5 wastewater treatment plants (WWTP) in Catalonia (Spain). All target OPFRs were detected in the WWTPs influents, and the total concentration ranged from 3.67 µg L(-1) to 150 µg L(-1). During activated sludge treatment, most OPFRs were accumulated in the sludge at concentrations from 35.3 to 9980 ng g(-1) dw. Chlorinated compounds tris(2-chloroethyl) phosphate (TCEP), tris(2-chloroisopropyl) phosphate (TCIPP) and tris(2,3-dichloropropyl) phosphate (TDCPP) were not removed by the conventional activated sludge treatment and they were released by the effluents at approximately the same inlet concentration. On the contrary, aryl compounds tris(methylphenyl) phosphate (TMPP) and 2-ethylhexyl diphenyl phosphate (EHDP) together with alkyl tris(2-ethylhexyl) phosphate (TEHP) were not detected in any of the effluents. Advanced oxidation processes (UV/H2O2 and O3) were applied to investigate the degradability of recalcitrant OPFRs in WWTP effluents. Those detected in the effluent sample (TCEP, TCIPP, TDCPP, tributyl phosphate (TNBP), tri-iso-butyl phosphate (TIBP) and tris(2-butoxyethyl) phosphate (TBOEP)) had very low direct UV-C photolysis rates. TBOEP, TNBP and TIBP were degraded by UV/H2O2 and O3. Chlorinated compounds TCEP, TDCPP and TCIPP were the most recalcitrant OPFR to the advanced oxidation processes applied. The study provides information on the partitioning and degradability pathways of OPFR within conventional activated sludge WWTPs.

  15. Wastewater treatment in a hybrid activated sludge baffled reactor

    Energy Technology Data Exchange (ETDEWEB)

    Tizghadam, Mostafa [Laboratoire des Sciences de l' Eau et de l' Environnement, Universite de Limoges, ENSIL, Parc ESTER, 16 Rue Atlantis, F-87068 Limoges Cedex (France); Dagot, Christophe [Laboratoire des Sciences de l' Eau et de l' Environnement, Universite de Limoges, ENSIL, Parc ESTER, 16 Rue Atlantis, F-87068 Limoges Cedex (France)], E-mail: dagot@ensil.unilim.fr; Baudu, Michel [Laboratoire des Sciences de l' Eau et de l' Environnement, Universite de Limoges, ENSIL, Parc ESTER, 16 Rue Atlantis, F-87068 Limoges Cedex (France)

    2008-06-15

    A novel hybrid activated sludge baffled reactor (HASBR), which contained both suspended and attached-growth biomass perfect mixing cells in series, was developed by installing standing and hanging baffles and introducing plastic brushes into a conventional activated sludge (CAS) reactor. It was used for the treatment of domestic wastewater. The effects on the operational performance of developing the suspended and attached-growth biomass and reactor configuration were investigated. The change of the flow regime from complete-mix to plug-flow, and the addition of plastic brushes as a support for biofilm, resulted in considerable improvements in the COD, nitrogen removal efficiency of domestic wastewater and sludge settling properties. In steady state, approximately 98 {+-} 2% of the total COD and 98 {+-} 2% of the ammonia of the influent were removed in the HASBR, when the influent wastewater concentration was 593 {+-} 11 mg COD/L and 43 {+-} 5 mg N/L, respectively, at a HRT of 10 h. These results were 93 {+-} 3 and 6 {+-} 3% for the CAS reactor, respectively. Approximately 90 {+-} 7% of the total COD was removed in the HASBR, when the influent wastewater concentration was 654 {+-} 16 mg COD/L at a 3 h HRT, and in the organic loading rate (OLR) of 5.36 kg COD m{sup -3} day{sup -1}. The result for the CAS reactor was 60 {+-} 3%. Existing CAS plants can be upgraded by changing the reactor configuration and introducing biofilm support media into the aeration tank.

  16. Acclimation of aerobic-activated sludge degrading benzene derivatives and co-metabolic degradation activities of trichloroethylene by benzene derivative-grown aerobic sludge.

    Science.gov (United States)

    Wang, Shizong; Yang, Qi; Bai, Zhiyong; Wang, Shidong; Wang, Yeyao; Nowak, Karolina M

    2015-01-01

    The acclimation of aerobic-activated sludge for degradation of benzene derivatives was investigated in batch experiments. Phenol, benzoic acid, toluene, aniline and chlorobenzene were concurrently added to five different bioreactors which contained the aerobic-activated sludge. After the acclimation process ended, the acclimated phenol-, benzoic acid-, toluene-, aniline- and chlorobenzene-grown aerobic-activated sludge were used to explore the co-metabolic degradation activities of trichloroethylene (TCE). Monod equation was employed to simulate the kinetics of co-metabolic degradation of TCE by benzene derivative-grown sludge. At the end of experiments, the mixed microbial communities grown under different conditions were identified. The results showed that the acclimation periods of microorganisms for different benzene derivatives varied. The maximum degradation rates of TCE for phenol-, benzoic acid-, toluene-, aniline- and chlorobenzene-grown aerobic sludge were 0.020, 0.017, 0.016, 0.0089 and 0.0047 mg g SS(-1) h(-1), respectively. The kinetic of TCE degradation in the absence of benzene derivative followed Monod equation well. Also, eight phyla were observed in the acclimated benzene derivative-grown aerobic sludge. Each of benzene derivative-grown aerobic sludge had different microbial community composition. This study can hopefully add new knowledge to the area of TCE co-metabolic by mixed microbial communities, and further the understanding on the function and applicability of aerobic-activated sludge.

  17. Application of contact stabilization activated sludge for enhancing biological phosphorus removal (EBPR in domestic wastewater

    Directory of Open Access Journals (Sweden)

    Ehab M. Rashed

    2014-04-01

    Full Text Available The experiment has been performed in order to investigate the effect of using contact stabilization activated sludge as an application of enhancing biological phosphorous removal (EBPR by using contact tank as a phosphorus uptake zone and using thickening tank as a phosphorus release zone. The study involved the construction of a pilot plant which was setup in Quhafa waste water treatment plant (WWTP that included contact, final sedimentation, stabilization and thickening tanks, respectively with two returns sludge in this system one of them to contact tank and another to stabilization tank. Then observation of the uptake and release of total phosphorus by achievement through two batch test using sludge samples from thickener and final sedimentations. Results showed the removal efficiencies of COD, BOD and TP for this pilot plant with the range of 94%, 85.44% and 80.54%, respectively. On the other hand the results of batch tests showed that the reason of high ability of phosphorus removal for this pilot plant related to the high performance of microorganisms for phosphorus accumulating. Finally the mechanism of this pilot plant depends on the removal of the phosphorus from the domestic waste water as a concentrated TP solution from the supernatant above the thickening zone not through waste sludge like traditional systems.

  18. Self-heating co-pyrolysis of excessive activated sludge with waste biomass: energy balance and sludge reduction.

    Science.gov (United States)

    Ding, Hong-Sheng; Jiang, Hong

    2013-04-01

    In this work, co-pyrolysis of sludge with sawdust or rice husk was investigated. The results showed that the co-pyrolysis technology could be used to dispose of the excessive activated sludge without external energy input. The results also demonstrated that no obvious synergistic effect occurred except for heat transfer in the co-pyrolysis if the co-feeding biomass and sludge had similar thermogravimetric characteristics. The experimental results combined with calculation showed that adding sawdust accounting for 49.6% of the total feedstock or rice husk accounting for 74.7% could produce bio-oil to keep the energy balance of the co-pyrolysis system and self-heat it. The sludge from solar drying bed can be further reduced by 38.6% and 35.1% by weight when co-pyrolyzed with rice husk and sawdust, respectively. This study indicates that sludge reduction without external heat supply through co-pyrolysis of sludge with waste biomass is practically feasible. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Activated sewage sludge, a potential animal foodstuff. Part I. Nutritional characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Tacon, A.G.J.

    1979-08-01

    The nutritive value of activated sewage sludge is discussed in terms of its amino acid N, non-amino acid N, carbohydrate, fat, mineral, vitamin and microbial content. Processed activated sewage sludge is described as a stable dark brown material of relatively uniform quality, having a nutritive value broadly equivalent to brewers yeast or a protein-rich cereal. The potential hazards associated with the use of activated sewage sludge as a feed ingredient are discussed. 29 references

  20. Changes at an activated sludge sewage treatment plant alter the numbers of airborne aerobic microorganisms.

    Science.gov (United States)

    Fernando, Nadeesha L; Fedorak, Phillip M

    2005-11-01

    In 1976, the activated sludge sewage treatment plant in Edmonton, Canada, was surveyed to determine the numbers of culturable airborne microorganisms. Many changes have been made at the plant to reduce odors and improve treatment efficiency, so in 2004 another survey was done to determine if these changes had reduced the bioaerosols. Covering the grit tanks and primary settling tanks greatly reduced the numbers of airborne microbes. Changing the design and operation of indoor automated sampling taps and sinks also reduced bioaerosols. The secondary was expanded and converted from a conventional activated sludge process using coarse bubble aeration to a biological nutrient removal system using fine bubble aeration. Although the surface area of the secondary more than doubled, the average number of airborne microorganisms in this part of the plant in 2004 was about 1% of that in 1976.

  1. Efficiency of conventional activated sludge in the removal of linear alkylbenzene sulfonate from municipal sewage

    Directory of Open Access Journals (Sweden)

    Razieh Khamutian

    2014-04-01

    Full Text Available Background: Linear Alkylbenzene Sulfonate (LAS is an anionic detergent that is abundantly produced in different countries and discharged into natural environment through wastewater collection systems. Wastewater treatment systems play an important role in the removal of this contaminant. The purpose of this study was to determine the efficiency of a conventional activated sludge system in removing linear alkylbenzene sulfonate from wastewater in Kermanshah. Methods: This cross-sectional descriptive study was conducted on the wastewater in Kermanshah for 10 months. In order to determine the efficiency of the influent activated sludge process, 60 wastewater samples were taken after primary sedimentation and effluent of wastewater treatment system and LAS concentration was measured. All the sampling and testing methods were performed according to the standard method guidelines. Results: The results showed the means of LAS removal in the winter and warm seasons were 90.8% and 96.5%, respectively. The total mean of LAS removal in this system was 93.9 ±3.6. In addition, COD and TSS removal levels in winter were 88.3% and 72.3%; these values, however, in the summer were 86.9%, and 83.3%, respectively. Conclusion: The results showed that the conventional activated sludge process plays a pivotal role in the removal of LAS concentration. Moreover, the effluent concentration of LAS is less than the environmental standards for discharge into surface water in warm seasons.

  2. Effect of gamma-ray irradiation on the dewaterability of waste activated sludge

    Science.gov (United States)

    Wu, Yuqi; Jiang, Yinghe; Ke, Guojun; Liu, Yingjiu

    2017-01-01

    The effect of gamma-ray irradiation on waste activated sludge (WAS) dewaterability was investigated with irradiation doses of 0-15 kGy. Time to filter (TTF50), specific resistance of filtration (SRF) and water content of sludge cake were measured to evaluate sludge dewaterability. Soluble chemical oxygen demand (SCOD), soluble extracellular polymeric substances (EPS) concentration and sludge particle size were determined to explain changes in sludge dewaterability. The optimal irradiation dose to obtain the maximum dewaterability characteristics was 1-4 kGy, which generated sludge with optimal disintegration (1.5-4.0%), soluble EPS concentration (590-750 mg/L) and particle size distribution (100-115 μm diameter). The combination of irradiation and cationic polyacrylamide (CPAM) addition exhibited minimal synergistic effect on increasing sludge dewatering rate compared with CPAM conditioning alone.

  3. Evaluation of anaerobic digestion processes for short sludge-age waste activated sludge combined with anammox treatment of digestate liquor.

    Science.gov (United States)

    Ge, Huoqing; Batstone, Damien; Keller, Jurg

    2016-01-01

    The need to reduce energy input and enhance energy recovery from wastewater is driving renewed interest in high-rate activated sludge treatment (i.e. short hydraulic and solids retention times (HRT and SRT, respectively)). This process generates short SRT activated sludge stream, which should be highly degradable. However, the evaluation of anaerobic digestion of short SRT sludge has been limited. This paper assesses anaerobic digestion of short SRT sludge digestion derived from meat processing wastewater under thermophilic and mesophilic conditions. The thermophilic digestion system (55°C) achieved 60 and 68% volatile solids destruction at 8 day and 10 day HRT, respectively, compared with 50% in the mesophilic digestion system (35°C, 10 day HRT). The digestion effluents from the thermophilic (8-10 day HRT) and mesophilic systems were stable, as assessed by residual methane potentials. The ammonia rich sludge dewatering liquor was effectively treated by a batch anammox process, which exhibited comparable nitrogen removal rate as the tests using a control synthetic ammonia solution, indicating that the dewatering liquor did not have inhibiting/toxic effects on the anammox activity.

  4. Analysis Of DWPF Sludge Batch 7a (Macrobatch 8) Pour Stream Samples

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, F. C.; Pareizs, J. M.

    2012-10-24

    The Defense Waste Processing Facility (DWPF) began processing Sludge Batch 7a (SB7a), also referred to as Macrobatch 8 (MB8), in June 2011. SB7a is a blend of the heel of Tank 40 from Sludge Batch 6 (SB6) and the SB7a material that was transferred to Tank 40 from Tank 51. SB7a was processed using Frit 418. During processing of each sludge batch, the DWPF is required to take at least one glass sample to meet the objectives of the Glass Product Control Program (GPCP), which is governed by the DWPF Waste Compliance Plan, and to complete the necessary Production Records so that the final glass product may be disposed of at a Federal Repository. Three pour stream glass samples and two Melter Feed Tank (MFT) slurry samples were collected while processing SB7a. These additional samples were taken during SB7a to understand the impact of antifoam and the melter bubblers on glass redox chemistry. The samples were transferred to the Savannah River National Laboratory (SRNL) where they were analyzed.

  5. Functions and behaviors of activated sludge extracellular polymeric substances (EPS): a promising environmental interest

    Institute of Scientific and Technical Information of China (English)

    TIAN Yu; ZHENG Lei; SUN De-zhi

    2006-01-01

    Extracellular polymeric substances (EPS) are the predominant constituents of activated sludge and represent up to 80% of the mass of activated sludge. They play a crucial role in the flocculation, settling and dewatering of activated sludge. Furthermore,EPS also show great efficiency in binding heavy metals. So EPS are key factors influencing reduction in sludge volume and mass, as well as activity and utilization of sludge. EPS are of considerable environmental interest and hundreds of articles on EPS have been published abroad, while information on EPS in China is limited. In this paper, results of over 60 publications related to constituents and characteristics of EPS and their influences on flocculation, settling and dewatering of sludge are compiled and analyzed.Metal-binding ability of EPS is also discussed, together with a brief consideration of possible research interests in the future.

  6. Heat and Bleach: A Cost-Efficient Method for Extracting Microplastics from Return Activated Sludge.

    Science.gov (United States)

    Sujathan, Surya; Kniggendorf, Ann-Kathrin; Kumar, Arun; Roth, Bernhard; Rosenwinkel, Karl-Heinz; Nogueira, Regina

    2017-05-26

    The extraction of plastic microparticles, so-called microplastics, from sludge is a challenging task due to the complex, highly organic material often interspersed with other benign microparticles. The current procedures for microplastic extraction from sludge are time consuming and require expensive reagents for density separation as well as large volumes of oxidizing agents for organic removal, often resulting in tiny sample sizes and thus a disproportional risk of sample bias. In this work, we present an improved extraction method tested on return activated sludge (RAS). The treatment of 100 ml of RAS requires only 6% hydrogen peroxide (H2O2) for bleaching at 70 °C, followed by density separation with sodium nitrate/sodium thiosulfate (SNT) solution, and is completed within 24 h. Extracted particles of all sizes were chemically analyzed with confocal Raman microscopy. An extraction efficiency of 78 ± 8% for plastic particle sizes 20 µm and up was confirmed in a recovery experiment. However, glass shards with a diameter of less than 20 µm remained in the sample despite the density of glass exceeding the density of the separating SNT solution by 1.1 g/cm(3). This indicates that density separation may be unreliable for particle sizes in the lower micrometer range.

  7. AN EXPERIMENTAL STUDY ON THE RHEOLOGICAL PROPERTIES OF CONDITIONED MUNICIPAL ACTIVATED SLUDGE

    Directory of Open Access Journals (Sweden)

    SALAM K. AL-DAWERY

    2017-01-01

    Full Text Available This research work was focused on the rheological characteristics of conditioned fresh activated sludge using TA rheometer HR-2. The effect of cationic polyelectrolyte conditioner has been investigated for floc size, surface properties and yield stress at different pH values in a comparative fashion. Our approach was to reveal the effect of polymer on the municipal activated sludge with high organic contents up to 80%. The results indicated an improvement of 50% in settling properties by addition polyelectrolyte up to 4 mg/g solid/l. Rheological data analysis showed that responses of shear stress - shear rate were found to be closest to Bingham model and gave almost similar and smaller k values of average 6.2×10-3. The results of shear creep indicated that all sludge samples have less rigid structures with no reconstruction behavior. The optical analyses of the samples indicated that the floc sizes were increased with successive addition of polyelectrolyte. The increase of floc sizes caused large stresses especially for solution with pH=9. As the flocculation accorded despite the negative zeta potential, this phenomenon can be referred to that interparticles hydrogen bridging was governing flocculation rather than charge neutralization. Also, during the experiment, bacterial growth showed an adaption despite the conditioning with polyelectrolyte.

  8. The in situ physiology of "Nostocoida limicola" II, a filamentous bacterial morphotype in bulking activated sludge, using fluorescence in situ hybridization and microautoradiography.

    Science.gov (United States)

    Seviour, E M; Eales, K; Izzard, L; Beer, M; Carr, E L; Seviour, R J

    2006-01-01

    The in situ physiology of the actinobacterial bulking and foaming filamentous bacterium "Nostocoida limicola" II was studied by fluorescence in situ hybridization/microautoradiography. Substrate assimilation patterns of pure cultures of this bacterium were different to those seen in activated sludge biomass samples. There was no evidence to suggest that "N. limicola" II preferred hydrophobic substrates, but evidence was produced to support the view that it is metabolically active under anaerobic conditions in activated sludge.

  9. The effect of the ammonium ion on activated-sludge settling properties

    DEFF Research Database (Denmark)

    Novak, John Thomas

    2001-01-01

    High levels of sodium in wastewater have been found to be detrimental to activated-sludge. settling and dewatering. Another potentially troublesome monovalent cation in activated-sludge systems is the ammonium ion. This study was conducted to determine if the ammonium ion could alter activated-sl...

  10. Optimization of the coke-oven activated sludge plants

    Energy Technology Data Exchange (ETDEWEB)

    Raizer Neto, Ernesto [Santa Catarina Univ., Florianopolis, SC (Brazil); Colin, Francois [Institut de Recherches Hydrologiques, 54 - Nancy (France); Prost, Christian [Laboratoire de Sciences de Genie Chimique, Nancy (France)

    1993-12-31

    In the coke-oven activated sludge plants one of the greatest problems of malfunction is due to inffluent variability. The composition and, or, concentration variations of the inffluent substrate, which can cause an unstable system, are function of the pollutant load. Nevertheless, the knowledge of the kinetic biodegradation of the coke-oven effluent represents the limiting factor to develop an effective biological treatment. This work describes a computational model of the biological treatment which was elaborated and validated from continuous pilot scale experiments and calibrated by comparing its predictions to the pilot experiment`s results. 12 refs., 9 figs., 3 tabs.

  11. Automated monitoring of activated sludge using image analysis

    OpenAIRE

    Motta, Maurício da; M. N. Pons; Roche, N; A.L. Amaral; Ferreira, E. C.; Alves, M.M.; Mota, M.; Vivier, H.

    2000-01-01

    An automated procedure for the characterisation by image analysis of the morphology of activated sludge has been used to monitor in a systematic manner the biomass in wastewater treatment plants. Over a period of one year, variations in terms mainly of the fractal dimension of flocs and of the amount of filamentous bacteria could be related to rain events affecting the plant influent flow rate and composition. Grand Nancy Council. Météo-France. Brasil. Ministério da Ciênc...

  12. Anoxic Activated Sludge Monitoring with Combined Nitrate and Titrimetric Measurements

    DEFF Research Database (Denmark)

    Petersen, B.; Gernaey, Krist; Vanrolleghem, P.A.

    2002-01-01

    An experimental procedure for anoxic activated sludge monitoring with combined nitrate and titrimetric measurements is proposed and evaluated successfully with two known carbon sources, (-)acetate and dextrose. For nitrate measurements an ion-selective nitrate electrode is applied to allow...... was with the carbon source in excess, since excess nitrate provoked nitrite build-up thereby complicating the data interpretation. A conceptual model could quantitatively describe the experimental observations and thus link the experimentally measured proton production with the consumption of electron acceptor...... and carbon source during denitrification....

  13. Exploring the Bioelectrochemical Characteristics of Activated Sludge Using Cyclic Voltammetry.

    Science.gov (United States)

    Khater, Dena Z; El-Khatib, K M; Hassan, Rabeay Y A

    2017-06-17

    Due to the potential interest, bioelectrochemical responses of activated sludge using the three-electrode system are tested. From the cyclic voltammograms, the oxidation current output is increasing due to incubation time increase, whereas 5, 25 and 39.33 μA are obtained after 3, 72 and 96 h, respectively. Changing the working electrode from glassy carbon to carbon paste led to the increase in the electrochemical signal from 0.3 to be 3.72 μA. On the other hand, the use of the lipophilic redox mediator (2,6-dichlorophenolindophenol (DCIP)) amplified the oxidation current to reach 19.9 μA instead of 2.1 μA. Based on these findings, the mixed microbial community of the activated sludge is exploited as a catalyst for the bio-oxidation of the degradable organic substrates, while DCIP is used as a mobile electron carrier from the intracellular matrix of the metabolically active cells to the carbon paste electrode which served as the final electron acceptor. Therefore, the extracellular electron transfer from the formed active biofilm at the electrode surface is assisted by the existence of DCIP.

  14. Hydrolytic activity of alpha-amylase in anaerobic digested sludge.

    Science.gov (United States)

    Higuchi, Y; Ohashi, A; Imachi, H; Harada, H

    2005-01-01

    Hydrolysis is usually considered to be a rate-limiting step in anaerobic digestion. For improving anaerobic solid waste treatments, it is essential to elucidate the mechanism of hydrolysis. In this study, alpha-amylase, one of the hydrolytic enzymes, was investigated for the elucidation of more precise mechanism of hydrolysis. Alpha-amylase activity of solid starch-degrading bacteria (SDB) was estimated through batch experiments with several different substrates and with distinction between cell-bound and cell-free alpha-amylase. Monitoring of newly isolated strains of SDB was done by fluorescence in situ hybridization. Results indicated that cell-bound alpha-amylase is chiefly responsible for the hydrolysis in the digested sludge, providing very useful information that the contact between microbial cells and solids is significantly important. The activity of alpha-amylase of the digested sludge remained quite low when not required, but increased as they recognized appropriate substrates. Several-fold higher activity was obtained for starch or maltose as compared to glucose only.

  15. Effects of waste activated sludge and surfactant addition on primary sludge hydrolysis and short-chain fatty acids accumulation.

    Science.gov (United States)

    Ji, Zhouying; Chen, Guanlan; Chen, Yinguang

    2010-05-01

    This paper focused on the effects of waste activated sludge (WAS) and surfactant sodium dodecylbenzene sulfonate (SDBS) addition on primary sludge (PS) hydrolysis and short-chain fatty acids (SCFA) accumulation in fermentation. The results showed that sludge hydrolysis, SCFA accumulation, NH(4)(+)-N and PO(4)(3-)-P release, and volatile suspended solids (VSS) reduction were increased by WAS addition to PS, which were further increased by the addition of SDBS to the mixture of PS and WAS. Acetic, propionic and valeric acids were the top three SCFA in all experiments. Also, the fermentation liquids of PS, PS+WAS, and PS+WAS+SDBS were added, respectively, to municipal wastewater to examine their effects on biological municipal wastewater treatment, and the enhancement of both wastewater nitrogen and phosphorus removals was observed compared with no fermentation liquid addition.

  16. Long term effects on petrochemical activated sludge on plants and soil. Plant growth and metal absorption

    Energy Technology Data Exchange (ETDEWEB)

    Tedesco, M.J.; Gianello, C. [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil). Dept. de Solos; Ribas, P.I.F.; Carvalho, E.B. [CORSAN-SITEL, Triunfo, RS (Brazil). Polo Petroquimico do Sul. Dept. de Operacao e Manutencao

    1993-12-31

    An experiment to study the effects of several application rates of excess activated sludge on plants, soil and leached water was started in 1985. Sludge was applied for six years and increased plant growth due to its nitrogen and phosphorous contribution, even though the decomposition rate in soil is low. Plant zinc, cadmium and nickel content increased with sludge application, while liming decreased the amounts of these metals taken up by plants. 9 refs., 8 tabs.

  17. Improving Settling Dynamics of Activated Sludge by Adding Fine Talc Powder

    DEFF Research Database (Denmark)

    Rasmussen, Michael R.; Larsen, Torben; Clauss, F.

    1996-01-01

    . The settling velocity was measured with a recirculated settling column under different concentrations and turbulence levels. Numerical simulation of a secondary settling tank indicates that adding fine powder will improve the overall performance considerably.......The effect of adding varying mixtures of talc and chlorite powder to activated sludge in order to improve the settling characteristic has been studied. The powder is found to improve the settling velocity of the sludge, strictly by increasing the average density of the sludge floc aggregate...

  18. Effect of low temperature on highly unsaturated fatty acid biosynthesis in activated sludge.

    Science.gov (United States)

    He, Su; Ding, Li-Li; Xu, Ke; Geng, Jin-Ju; Ren, Hong-Qiang

    2016-07-01

    Low temperature is a limiting factor for the microbial activity of activated sludge for sewage treatment plant in winter. Highly unsaturated fatty acid (UFA) biosynthesis, phospholipid fatty acid (PLFA) constituents and microbial structure in activated sludge at low temperature were investigated. Over 12 gigabases of metagenomic sequence data were generated with the Illumina HiSeq 2000 platform. The result showed 43.11% of phospholipid fatty acid (PLFA) in the activated sludge participated in UFA biosynthesis, and γ-Linolenic could be converted to Arachidonic acid at low temperature. The highly UFA biosynthesis in activated sludge was n-6 highly UFA biosynthesis, rather than n-3 highly UFA biosynthesis. The microbial community structures of activated sludge were analyzed by PLFA and high-throughput sequencing (HiSeq) simultaneously. Acidovorax, Pseudomonas, Flavobacterium and Polaromonas occupied higher percentage at 5°C, and genetic changes of highly UFA biosynthesis derived from microbial community structures change.

  19. Identification of new bacteria harboring qnrS and aac(6')-Ib/cr and mutations possibly involved in fluoroquinolone resistance in raw sewage and activated sludge samples from a full-scale WWTP.

    Science.gov (United States)

    Paiva, Magna C; Reis, Mariana P; Costa, Patrícia S; Dias, Marcela F; Bleicher, Lucas; Scholte, Larissa L S; Nardi, Regina M D; Nascimento, Andréa M A

    2017-03-01

    Wastewater treatment plants (WWTPs) harbor bacteria and antimicrobial resistance genes, favoring gene exchange events and resistance dissemination. Here, a culture-based and metagenomic survey of qnrA, qnrB, qnrS, and aac(6')-Ib genes from raw sewage (RS) and activated sludge (AS) of a full-scale municipal WWTP was performed. A total of 96 bacterial isolates were recovered from nalidixic acid-enrichment cultures. Bacteria harboring the aac(6')-Ib gene predominated in RS, whereas qnrS-positive isolates were specific to AS. Novel qnrS- and aac(6')-Ib-cr positive species were identified: Morganella morganii, Providencia rettgeri, and Pseudomonas guangdongensis (qnrS), and Alcaligenes faecalis and P. rettgeri (aac(6')-Ib-cr). Analysis of qnrS and aac(6')-Ib sequences from isolates and clone libraries suggested that the diversity of qnrS is wider than that of aac(6')-Ib. A large number of amino acid mutations were observed in the QnrS and AAC(6')-Ib proteins at previously undetected positions, whose structural implications are not clear. An accumulation of mutations at the C72, Q73, L74, A75 and M76 positions of QnrS, and D181 of AAC(6')-Ib might be important for resistance. These findings add significant information on bacteria harboring qnrS and aac(6')-Ib genes, and the presence of novel mutations that may eventually emerge in clinical isolates. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Foaming Scum Index (FSI)--a new tool for the assessment and characterisation of biological mediated activated sludge foams.

    Science.gov (United States)

    Fryer, Martin; Gray, N F

    2012-11-15

    The formation of thick stable brown foams within the activated sludge process has become a familiar operational problem. Despite much research having already been carried out into establishing the causes of activated sludge foaming there is still no general consensus on the mechanisms involved. Historically investigation into activated sludge foaming has involved either measuring, under aeration conditions, the propensity of mixed liquor samples to foam, or evaluating different physico-chemical properties of the sludge which have previously been linked to activated sludge foaming. Both approaches do not present a means to quantify the risk posed to the treatment plants once foams have started to develop on the surface of aeration basins and final clarifiers. The Foaming Scum Index (FSI) is designed to offer a means to quantify risk on the basis of different foam characteristics which can easily be measured. For example, foam stability, foam coverage, foam suspended solids content and biological composition. The FSI was developed by measuring foam samples taken from several different domestic and municipal wastewater treatment sites located in Greater Dublin area (South-East Ireland). Path analysis was used to predict co-dependencies among the different sets of variables following a number of separate hypotheses. The standardized beta coefficients (β) produced from the multivariate correlation analysis (providing a measure of the contribution of each variable in the structural equation model) was used to finalise the weighting of each parameter in the index accordingly. According to this principal, foam coverage exerted the greatest influence on the overall FSI (β = 0.33), whilst the filamentous bacterial composition in terms of the filament index of foam, provided the least (β = 0.03). From this work it is proposed that the index can be readily applied as a standard tool in the coordination of research into the phenomenon of activated sludge foaming.

  1. Accurate assessment of the biodegradation of cationic surfactants in activated sludge reactors (OECD TG 303A)

    NARCIS (Netherlands)

    Geerts, R.; Ginkel, van C.G.; Plugge, C.M.

    2015-01-01

    The continuous-fed activated sludge test (OECD TG 303A) was used to predict the removal of cationic surfactants from wastewater in activated sludge plants. However, a method to differentiate between adsorption and biodegradation is not provided in these guidelines. Assessment of removal by biodegrad

  2. Biodegradation of triclosan and formation of methyl-triclosan in activated sludge under aerobic conditions

    DEFF Research Database (Denmark)

    Chen, Xijuan; Nielsen, Jeppe Lund; Furgal, Karolina

    2011-01-01

    of triclosan- methyl was investigated in activated sludge from a standard activated sludge WWTP equipped with enhanced biological phosphorus removal. The removal was found to occur mainly under aerobic conditions while under anoxic (nitrate reducing) and anaerobic conditions rather low removal rates were...

  3. Accurate assessment of the biodegradation of cationic surfactants in activated sludge reactors (OECD TG 303A)

    NARCIS (Netherlands)

    Geerts, R.; Ginkel, van C.G.; Plugge, C.M.

    2015-01-01

    The continuous-fed activated sludge test (OECD TG 303A) was used to predict the removal of cationic surfactants from wastewater in activated sludge plants. However, a method to differentiate between adsorption and biodegradation is not provided in these guidelines. Assessment of removal by biodegrad

  4. Modelling of the Secondary Clarifier Combined with the Activated Sludge Model no. 1

    DEFF Research Database (Denmark)

    Dupont, René; Henze, Mogens

    1992-01-01

    Modelling of activated sludge wastewater treatment plants is today generally based on the Activated Sludge Model No. 1 combined with a very simple model for the secondary settler. This paper describes the development of a model for the secondary clarifier based on the general flux theory for zone...

  5. Accurate assessment of the biodegradation of cationic surfactants in activated sludge reactors (OECD TG 303A)

    NARCIS (Netherlands)

    Geerts, R.; Ginkel, van C.G.; Plugge, C.M.

    2015-01-01

    The continuous-fed activated sludge test (OECD TG 303A) was used to predict the removal of cationic surfactants from wastewater in activated sludge plants. However, a method to differentiate between adsorption and biodegradation is not provided in these guidelines. Assessment of removal by

  6. Bacterial Diversity of Active Sludge in Wastewater Treatment Plant

    Science.gov (United States)

    Jiang, Xin; Ma, Mingchao; Li, Jun; Lu, Anhuai; Zhong, Zuoshen

    A bacterial 16S rDNA gene clone library was constructed to analyze the bacterial diversity of active sludge in Gaobeidian Wastewater Treatment Plant, Beijing. The results indicated that the bacterial diversity of active sludge was very high, and the clones could be divided into 5 different groups. The dominant bacterial community was proteobacteria, which accounted for 76.7%. The dominant succession of bacterial community were as follows: the β-proteobacteria (39.8%), the uncultured bacteria (22.33%), the γ-proteobacteria (20.15%), the α-proteobacteria (6.79%), and the σ-proteobacteria (4.85%). Nitrosomonas-like and Nitrospira-like bacteria, such as Nitrosomonas sp. (1.94%) and uncultured Nitrospirae bacterium (11.65%) were also detected, which have played important roles in ammonia and nitrite oxidisers in the system. However, they were only a little amount because of their slow growth and less competitive advantage than heterotrophic bacteria. Denitrifying bacteria like Thauera sp. was at a high percentage, which implies a strong denitrification ability; Roseomonas sp. was also detected in the clone library, which could be related to the degradation of organophosphorus pesticide.

  7. "The Effects of Temperature and PH on Settlability of Activated Sludge Flocs"

    Directory of Open Access Journals (Sweden)

    Gh Ghanizadeh

    2001-09-01

    Full Text Available The effluent quality of a sewage treatment plant using activated sludge process and finally secondary treatment depends on the flocculation efficiency and settling of the flocs. The survey of various treatment processes in water and wastewater treatment shows that temperature and pH are the important factors affecting efficiency of flocculation and settling properties. This study was performed to determine the effects of pH and temperature on settling of the flocs in activated sludge process. It was carried out for three months in two phases, using mixed liquor suspended solids (MLSS, obtained from aeration tank from one of wastewater treatment plants in Tehran. In the primary phase, the temperature of samples was increased from 15°C to 35°C. As a result, the sludge volume index (SVI and effluent suspended solids increased and consequently, COD removal percent decreased. In the second phase, the pH was increased from 5.7 to 9. As a result, SVI and effluent suspended solids decreased and COD removal percent increased.

  8. Toxic influence of silver and uranium salts on activated sludge of wastewater treatment plants and synthetic activated sludge associates modeled on its pure cultures.

    Science.gov (United States)

    Tyupa, Dmitry V; Kalenov, Sergei V; Skladnev, Dmitry A; Khokhlachev, Nikolay S; Baurina, Marina M; Kuznetsov, Alexander Ye

    2015-01-01

    Toxic impact of silver and uranium salts on activated sludge of wastewater treatment facilities has been studied. Some dominating cultures (an active nitrogen fixer Agrobacterium tumifaciens (A.t) and micromyces such as Fusarium nivale, Fusarium oxysporum, and Penicillium glabrum) have been isolated and identified as a result of selection of the activated sludge microorganisms being steadiest under stressful conditions. For these cultures, the lethal doses of silver amounted 1, 600, 50, and 300 µg/l and the lethal doses of uranium were 120, 1,500, 1,000, and 1,000 mg/l, respectively. A.tumifaciens is shown to be more sensitive to heavy metals than micromyces. Synthetic granular activated sludge was formed on the basis of three cultures of the isolated micromyces steadiest against stress. Its granules were much more resistant to silver than the whole native activated sludge was. The concentration of silver causing 50 % inhibition of synthetic granular activated sludge growth reached 160-170 μg/l as far as for the native activated sludge it came only to 100-110 μg/l.

  9. Determination of ring correction factors for leaded gloves used in grab sampling activities at Hanford tank farms

    Energy Technology Data Exchange (ETDEWEB)

    RATHBONE, B.A.

    1999-06-24

    This study evaluates the effectiveness of lead lined gloves in reducing extremity dose from two sources specific to tank waste sampling activities: (1) sludge inside glass sample jars and (2) sludge as thin layer contamination on the exterior surface of sample jars. The response of past and present Hanford Extremity Dosimeters (ring) designs under these conditions is also evaluated.

  10. Influences of influent carbon source on extracellular polymeric substances (EPS) and physicochemical properties of activated sludge.

    Science.gov (United States)

    Ye, Fenxia; Peng, Ge; Li, Ying

    2011-08-01

    It is necessary to understand the bioflocculation, settling and dewatering characteristics in the activated sludge process in order to establish more efficient operational strategies. The influences of carbon source on the extracellular polymeric substances (EPS) and flocculation, settling and dewatering properties of the activated sludge were investigated. Laboratory-scale completely mixed activated sludge processes were used to grow the activated sludge with different carbon sources of starch, glucose and sodium acetate. The sludge fed with acetate had highest loosely bound EPS (LB-EPS) and that fed with starch lowest. The amount of tightly bound EPS (TB-EPS), protein content in LB-EPS, polysaccharide content and protein contents in TB-EPS, were independent of the influent carbon source. The polysaccharide content in LB-EPS of the activated sludge fed with sodium acetate was lower slightly than those of starch and glucose. The sludge also had a nearly consistent flocs size and the sludge volume index (SVI) value. ESS content of the sludge fed with sodium acetate was higher initially, although it was similar to those fed with glucose and starch finally. However, the specific resistance to filtration and normalized capillary suction time fluctuated first, but finally were stable at around 5.0×10(8)mkg(-1) and 3.5 s Lg(-1) SS, respectively. Only the protein content in LB-EPS weakly correlated with the flocs size and SVI of the activated sludge. But there was no correlation between any other EPS contents or components and the physicochemical properties of the activated sludge.

  11. ANALYSIS OF DWPF SLUDGE BATCH 7A (MACROBATCH 8) POUR STREAM SAMPLES

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, F.

    2012-05-01

    The Defense Waste Processing Facility (DWPF) began processing Sludge Batch 7a (SB7a), also referred to as Macrobatch 8 (MB8), in June 2011. SB7a is a blend of the heel of Tank 40 from Sludge Batch 6 (SB6) and the SB7a material that was transferred to Tank 40 from Tank 51. SB7a was processed using Frit 418. During processing of each sludge batch, the DWPF is required to take at least one glass sample to meet the objectives of the Glass Product Control Program (GPCP), which is governed by the DWPF Waste Compliance Plan, and to complete the necessary Production Records so that the final glass product may be disposed of at a Federal Repository. Three pour stream glass samples and two Melter Feed Tank (MFT) slurry samples were collected while processing SB7a. These additional samples were taken during SB7a to understand the impact of antifoam and the melter bubblers on glass redox chemistry. The samples were transferred to the Savannah River National Laboratory (SRNL) where they were analyzed. The following conclusions were drawn from the analytical results provided in this report: (1) The sum of oxides for the official SB7a pour stream glass is within the Product Composition Control System (PCCS) limits (95-105 wt%). (2) The average calculated Waste Dilution Factor (WDF) for SB7a is 2.3. In general, the measured radionuclide content of the official SB7a pour stream glass is in good agreement with the calculated values from the Tank 40 dried sludge results from the SB7a Waste Acceptance Program Specification (WAPS) sample. (3) As in previous pour stream samples, ruthenium and rhodium inclusions were detected by Scanning Electron Microscopy-Electron Dispersive Spectroscopy (SEM-EDS) in the official SB7a pour stream sample. (4) The Product Consistency Test (PCT) results indicate that the official SB7a pour stream glass meets the waste acceptance criteria for durability with a normalized boron release of 0.64 g/L, which is an order of magnitude less than the Environmental

  12. Identification of Quorum-Sensing Signal Molecules and a Biosynthetic Gene in Alicycliphilus sp. Isolated from Activated Sludge

    Directory of Open Access Journals (Sweden)

    Tomohiro Morohoshi

    2016-08-01

    Full Text Available Activated sludge is a complicated mixture of various microorganisms that is used to treat sewage and industrial wastewater. Many bacteria produce N-acylhomoserine lactone (AHL as a quorum-sensing signal molecule to regulate the expression of the exoenzymes used for wastewater treatment. Here, we isolated an AHL-producing bacteria from an activated sludge sample collected from an electronic component factory, which we named Alicycliphilus sp. B1. Clone library analysis revealed that Alicycliphilus was a subdominant genus in this sample. When we screened the activated sludge sample for AHL-producing strains, 12 of 14 the AHL-producing isolates were assigned to the genus Alicycliphilus. A putative AHL-synthase gene, ALISP_0667, was cloned from the genome of B1 and transformed into Escherichia coli DH5α. The AHLs were extracted from the culture supernatants of the B1 strain and E. coli DH5α cells harboring the ALISP_0667 gene and were identified by liquid chromatography-mass spectrometry as N-(3-hydroxydecanoyl-l-homoserine lactone and N-(3-hydroxydodecanoyl-l-homoserine lactone. The results of comparative genomic analysis suggested that the quorum-sensing genes in the B1 strain might have been acquired by horizontal gene transfer within activated sludge.

  13. MiDAS Field Guide – a Comprehensive Online Source of Information About the Microbes of Activated Sludge

    DEFF Research Database (Denmark)

    Nierychlo, Marta; McIlroy, Simon Jon; Saunders, Aaron Marc

    in MiDAS collection has an up-to-date description of all the important metabolic features, morphology, available FISH probes, genomic data and other relevant information based on the published literature. Additionally, the protocols for DNA extraction and 16S Amplicon Sequencing sample preparation...... that would be otherwise excluded from analyses. The MiDAS database importantly provides a common taxonomy for the field that gives a solid foundation for the study of microbial ecology of the activated sludge process and related wastewater treatment processes, such as biofilms and granular sludge. Each genus...

  14. Effects of Metal Nanoparticles on Methane Production from Waste-Activated Sludge and Microorganism Community Shift in Anaerobic Granular Sludge

    Science.gov (United States)

    Wang, Tao; Zhang, Dong; Dai, Lingling; Chen, Yinguang; Dai, Xiaohu

    2016-05-01

    Extensive use of nanoparticles (NPs) in consumer and industrial products has led to concerns about their potential environmental impacts; however, the influences of different NPs (e.g., nZVI (nano zero-valent iron), Ag NPs, Fe2O3 NPs and MgO NPs) on the anaerobic digestion of sludge have not yet been studied in depth. Additionally, a new guideline or the use of different NPs in the anaerobic digestion of sludge should be established to improve the anaerobic digestion of sludge and avoid inhibitory effects. This study investigated the effects of four representative NPs (i.e., nZVI, Ag NPs, Fe2O3 NPs and MgO NPs) on methane production during the anaerobic digestion of waste activated sludge (WAS). The presence of 10 mg/g total suspended solids (TSS) nZVI and 100 mg/g TSS Fe2O3 NPs increased methane production to 120% and 117% of the control, respectively, whereas 500 mg/g TSS Ag NPs and 500 mg/g TSS MgO NPs generated lower levels of methane production (73.52% and 1.08% that of the control, respectively). These results showed that low concentrations of nZVI and Fe2O3 NPs promoted the amount of microbes (Bacteria and Archaea) and activities of key enzymes but that higher concentrations of Ag NPs and MgO NPs inhibited them.

  15. Analysis Of The Sludge Batch 7b (Macrobatch 9) DWPF Pour Stream Glass Sample

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, F. C.; Crawford, C. L.; Pareizs, J. M.

    2013-11-18

    The Defense Waste Processing Facility (DWPF) began processing Sludge Batch 7b (SB7b), also referred to as Macrobatch 9 (MB9), in January 2012. SB7b is a blend of the heel of Tank 40 from Sludge Batch 7a (SB7a) and the SB7b material that was transferred to Tank 40 from Tank 51. SB7b was processed using Frit 418. During processing of each sludge batch, the DWPF is required to take at least one glass sample to meet the objectives of the Glass Product Control Program (GPCP), which is governed by the DWPF Waste Form Compliance Plan, and to complete the necessary Production Records so that the final glass product may be disposed of at a Federal Repository. Two pour stream glass samples were collected while processing SB7b. The samples were transferred to the Savannah River National Laboratory (SRNL) where one was analyzed and the other was archived. The following conclusions were drawn from the analytical results provided in this report: The sum of oxides for the official SB7b pour stream glass is within the Product Composition Control System (PCCS) limits (95-105 wt%); The average calculated Waste Dilution Factor (WDF) for SB7b is 2.3. In general, the measured radionuclide content of the official SB7b pour stream glass is in good agreement with the calculated values from the Tank 40 dried sludge results from the SB7b Waste Acceptance Program Specification (WAPS) sample; As in previous pour stream samples, ruthenium and rhodium inclusions were detected by Scanning Electron Microscopy-Electron Dispersive Spectroscopy (SEM-EDS) in the SB7b pour stream sample; The Product Consistency Test (PCT) results indicate that the official SB7b pour stream glass meets the waste acceptance criteria for durability with a normalized boron release of 0.8 g/L, which is an order of magnitude less than the Environmental Assessment (EA) glass; The measured density of the SB7b pour stream glass was 2.70 g/cm{sup 3}; The Fe{sup 2+}/ΣFe ratio of the SB7b pour stream samples was 0.07.

  16. Improving Settling Characteristics of Pure Oxygen Activated Sludge by Stripping of Carbon Dioxide.

    Science.gov (United States)

    Kundral, Somshekhar; Mudragada, Ratnaji; Coro, Ernesto; Moncholi, Manny; Mora, Nelson; Laha, Shonali; Tansel, Berrin

    2015-06-01

    Increased microbial activity at high ambient temperatures can be problematic for secondary clarifiers and gravity concentrators due to carbon dioxide (CO2) production. Production of CO2 in gravity concentrators leads to septic conditions and poor solids separation. The CO2 production can also be corrosive for the concrete surfaces. Effectiveness of CO2 stripping to improve solids settling was investigated using the sludge volume index (SVI) as the indicator parameter. Carbon dioxide was stripped by aeration from the sludge samples. Results from the study show that aeration also increased the pH values in the mixed liquor while removing CO2 and improving sludge settling. After 10 minutes of aeration at a rate of 0.37 m3 air/m3 water/min, 90% CO2 stripping was achieved. Based on the 30 min settling tests, the SVI increased by 26±1% after CO2 stripping while the pH increased by 0.8±0.1 pH units.

  17. Ecological and kinetic aspects of amylolysis and proteolysis in activated sludge

    NARCIS (Netherlands)

    Janssen, J.M.A.

    1979-01-01

    An investigation has been made of the enzymic degradation of biopolymers by activated sludge. Starch was chosen as the model substrate; it was administered continuously at different sludge loading values which covered the entire range of loadings applied in sewage purification plants. The

  18. Identification and quantification of nitrogen nutrient deficiency in the activated sludge process using respirometry

    NARCIS (Netherlands)

    Ning, Z.; Patry, G.G.; Spanjers, H.

    2000-01-01

    Experimental protocols to identify and quantify nitrogen nutrient deficiency in the activated sludge process were developed and tested using respirometry. Respirometric experiments showed that when a nitrogen nutrient deficient sludge is exposed to ammonia nitrogen, the oxygen uptake rate (OUR) of t

  19. Identification and quantification of nitrogen nutrient deficiency in the activated sludge process using respirometry

    NARCIS (Netherlands)

    Ning, Z.; Patry, G.G.; Spanjers, H.

    2000-01-01

    Experimental protocols to identify and quantify nitrogen nutrient deficiency in the activated sludge process were developed and tested using respirometry. Respirometric experiments showed that when a nitrogen nutrient deficient sludge is exposed to ammonia nitrogen, the oxygen uptake rate (OUR) of

  20. SUMMARY REPORT: THE CAUSES AND CONTROL OF ACTIVATED SLUDGE BULKING AND FOAMING

    Science.gov (United States)

    This 92-page Technology Transfer Summary Report provides reference material on the causes and controls of sludge bulking and foaming in activated sludge treatment that can be readily understood, and it includes sufficient detail to help plant operators control their systems. The ...

  1. Ecological and kinetic aspects of amylolysis and proteolysis in activated sludge

    NARCIS (Netherlands)

    Janssen, J.M.A.

    1979-01-01

    An investigation has been made of the enzymic degradation of biopolymers by activated sludge. Starch was chosen as the model substrate; it was administered continuously at different sludge loading values which covered the entire range of loadings applied in sewage purification plants. The acclimatiz

  2. Anaerobic co-digestion of waste activated sludge and greasy sludge from flotation process: batch versus CSTR experiments to investigate optimal design.

    Science.gov (United States)

    Girault, R; Bridoux, G; Nauleau, F; Poullain, C; Buffet, J; Peu, P; Sadowski, A G; Béline, F

    2012-02-01

    In this study, the maximum ratio of greasy sludge to incorporate with waste activated sludge was investigated in batch and CSTR experiments. In batch experiments, inhibition occurred with a greasy sludge ratio of more than 20-30% of the feed COD. In CSTR experiments, the optimal greasy sludge ratio was 60% of the feed COD and inhibition occurred above a ratio of 80%. Hence, batch experiments can predict the CSTR yield when the degradation phenomenon are additive but cannot be used to determine the maximum ratio to be used in a CSTR configuration. Additionally, when the ratio of greasy sludge increased from 0% to 60% of the feed COD, CSTR methane production increased by more than 60%. When the greasy sludge ratio increased from 60% to 90% of the feed COD, the reactor yield decreased by 75%.

  3. Development of a model describing virus removal process in an activated sludge basin

    Energy Technology Data Exchange (ETDEWEB)

    Kim, T.; Shiragami, N. Unno, H. [Tokyo Institute of Technology, Tokyo (Japan)

    1995-06-20

    The virus removal process from the liquid phase in an activated sludge basin possibly consists of physicochemical processes, such as adsorption onto sludge flocs, biological processes such as microbial predating and inactivation by virucidal components excreted by microbes. To describe properly the virus behavior in an activated sludge basin, a simple model is proposed based on the experimental data obtained using a poliovirus type 1. A three-compartments model, which include the virus in the liquid phase and in the peripheral and inner regions of sludge flocs is employed. By using the model, the Virus removal process was successfully simulated to highlight the implication of its distribution in the activated sludge basin. 17 refs., 8 figs.

  4. Dynamic fouling behaviors of submerged nonwoven bioreactor for filtration of activated sludge with different SRT.

    Science.gov (United States)

    Chuang, Shun-Hsing; Lin, Po-Kuen; Chang, Wei-Chin

    2011-09-01

    The flux variations and resistances accumulated during filtration of activated sludge with sludge retention time (SRT) of 15, 30, and 60 days were analyzed to investigate the dynamic fouling behavior in a submerged nonwoven bioreactor. Different SRT values varied sludge condition and particle size distribution in the supernatants, which caused dissimilar fouling characteristics. Short-term fouling of the nonwoven bioreactor during filtration of activated sludge with SRT of 15 days was fully reversible, and the resistance percentages of solutes, colloids, and suspended solids were 6%, 27%, and 67%, respectively. On the other hand, significant increases of colloid resistance, such as with the filtration of activated sludge with SRT of 30 and 60 days, were related to the occurrence of irreversible fouling. The phenomenon of pore blocking by particles or colloids with size analogous to the pore of nonwoven fabric was a decisive factor leading to irreversible fouling in the large-pore materials.

  5. New insight into the biological treatment by activated sludge: the role of adsorption process.

    Science.gov (United States)

    Zhang, Xiaochun; Li, Xinrun; Zhang, Qingrui; Peng, Qiuming; Zhang, Wen; Gao, Faming

    2014-02-01

    The objective of this study was to evaluate the effect of adsorption on the biological treatment process of wastewater. In the absence of substrate in the water, activated sludge developed well in the first hour, indicating that the growth of microorganism was not directly related to substrate concentration and the dissolved organic matter in the water assays were performed, no organic matter was detected out, revealing that there was no desorption in the activated sludge adsorption process. Activated sludge batch growth experiments in the presence of different adsorption capacities indicated that specific growth rate increased as specific adsorption capacity increased. The experiment on the relationship of adsorption capacity and substrate concentration or sludge concentration was also carried out. Specific adsorption capacity increased as sludge load increased, presenting linear correlation. The experiment results showed that adsorption should be taken into account in the study of the biological treatment process of wastewater.

  6. Kinetics of continuous biodegradation of pesticide organic wastewater by activated carbon-activated sludge

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Organic triazophos wastewater was continuously treated with Rhodopseudomonas capsulatus and activated carbon and activated sludge system(PACT-AS) in a plug bioreactor. A kinetic model of PACT-AS wastewater treatment system was established to provide an useful basis for further simulate scale-up treatment of toxic organic wastewater.

  7. An activated sludge model for xenobiotic organic micro-pollutants (ASM-X)

    DEFF Research Database (Denmark)

    Plósz, Benedek; Lehnberg, K.; Dott, W.

    2010-01-01

    the XOMs content of pre-clarified municipal sewage. Evaluation of the model structure is carried out in dynamic simulations using data obtained in samples taken in a measuring campaign in a full-scale activated sludge wastewater treatment plant (WWTP). Our results suggest that the sorption...... deteriorate; thereby hindering the effluent quality of secondary treatment step, and thereby increasing the XOM mass load on the tertiary treatment step. Besides the impact of different redox conditions, divalent iron-salt dosing used for enhanced phosphorus removal and pH have been identified as potential...

  8. THE EFFECT OF THE SLUDGE RECYCLE RATIO IN AN ACTIVATED SLUDGE SYSTEM FOR THE TREATMENT OF AMOL'S INDUSTRIAL PARK WASTEWATER

    Directory of Open Access Journals (Sweden)

    BAHAR HOSSEINI

    2008-09-01

    Full Text Available An activated sludge aeration tank and a sedimentation basin were used to treat Amol’s industrial park effluents originating from all industrial units. A continuous system was implemented and the kinetic parameters were measured.The parameters such as rate constant, substrate utilization rate constant, yield and decay coefficient were 2.12 d-1, 232.4 mg l-1, 0.33 g/g of substrate and 0.096 d−1, respectively. The hydraulic retention times (HRT were in the range of 9 to 27 h. The sludge recycle ratios in the range from 0.3 to 1 were considered. The COD removal, SVI and DO were determined and the optimal values were obtained. It was observed that at HRT of 16 h and the sludge recycle ratio of 0.85, the COD removal and SVI were 95 and 85 %, respectively. The sludge recycle ratio greater than 0.85 had no significant effect on the COD removal.

  9. Nitrogen removal from wastewater and external waste activated sludge reutilization/reduction by simultaneous sludge fermentation, denitrification and anammox (SFDA).

    Science.gov (United States)

    Wang, Bo; Peng, Yongzhen; Guo, Yuanyuan; Zhao, Mengyue; Wang, Shuying

    2016-08-01

    This work demonstrates the feasibility of simultaneous nitrogen removal and external waste activated sludge (WAS) reutilization/reduction by using the synergy of sludge fermentation, denitrification and anammox processes in up-flow reactors (SFDA). Pre-treated domestic wastewater and synthetic wastewater (containing nitrite ∼20mg/L, ammonium ∼10mg/L in both) were fed to 1# and 2# SFDA, respectively. Long-term operation of 1# SFDA was investigated with achieving the peak ammonium removal rate of 0.021 and nitrite removal rate of 0.081kgN/(m(3)d) as nitrogen loading rate elevated from 0.075 to 0.106kgN/(m(3)d). Negative effect of dissolved oxygen on anammox or fermentation in the 2# SFDA was demonstrated negligible due to rapid depletion by microorganisms. Furthermore, a "net" sludge reduction of 38.8% was obtained due to sludge decay and organics consumption by denitrification. The SFDA process was expected to potentially be used for nitrogen removal and WAS reutilization/reduction in full-scale application.

  10. [Comparative Metagenomics of BIOLAK and A2O Activated Sludge Based on Next-generation Sequencing Technology].

    Science.gov (United States)

    Tian, Mei; Liu, Han-hu; Shen, Xin

    2016-02-15

    This is the first report of comparative metagenomic analyses of BIOLAK sludge and anaerobic/anoxic/oxic (A2O) sludge. In the BIOLAK and A2O sludge metagenomes, 47 and 51 phyla were identified respectively, more than the numbers of phyla identified in Australia EBPR (enhanced biological phosphorus removal), USA EBPR and Bibby sludge. All phyla found in the BIOLAK sludge were detected in the A2O sludge, but four phyla were exclusively found in the A20 sludge. The proportion of the phylum Ignavibacteriae in the A2O sludge was 2.0440%, which was 3.2 times as much as that in the BIOLAK sludge (0.6376%). Meanwhile, the proportion of the bacterial phylum Gemmatimonadetes in the BIOLAK sludge was 2.4673%, which was >17 times as much as that in the A2O sludge (0.1404%). The proportion of the bacterial phylum Chlamydiae in the BIOLAK metagenome (0.2192%) was >6 times higher than that in the A2O (0.0360%). Furthermore, 167 genera found in the A20 sludge were not detected in the BIOLAK sludge. And 50 genera found in the BIOLAK sludge were not detected in the A20 sludge. From the analyses of both the phylum and genus levels, there were huge differences between the two biological communities of A2O and BIOLAK sludge. However, the proportions of each group of functional genes associated with metabolism of nitrogen, phosphor, sulfur and aromatic compounds in BIOLAK were very similar to those in A2O sludge. Moreover, the rankings of all six KEGG (Kyoto Encyclopedia for Genes and Genomes) categories were identical in the two sludges. In addition, the analyses of functional classification and pathway related nitrogen metabolism showed that the abundant enzymes had identical ranking in the BIOLAK and A2O metagenomes. Therefore, comparative metagenomics of BIOLAK and A2O activated sludge indicated similar function assignments from the two different biological communities.

  11. Genomic and in situ investigations of the novel uncultured Chloroflexi associated with 0092 morphotype filamentous bulking in activated sludge

    DEFF Research Database (Denmark)

    McIlroy, Simon Jon; Karst, Søren Michael; Nierychlo, Marta;

    2016-01-01

    Overgrowth of filamentous bacteria in activated sludge wastewater treatment plants (WWTPs) leads to impaired sludge settleability, a condition known as bulking, which is a common operational problem worldwide. Filaments with the Eikelboom 0092 morphotype are commonly associated with such bulking...

  12. Environmental monitoring study of linear alkylbenzene sulfonates and insoluble soap in Spanish sewage sludge samples.

    Science.gov (United States)

    Cantarero, Samuel; Zafra-Gómez, Alberto; Ballesteros, Oscar; Navalón, Alberto; Reis, Marco S; Saraiva, Pedro M; Vílchez, José L

    2011-01-01

    In this work we present a monitoring study of linear alkylbenzene sulfonates (LAS) and insoluble soap performed on Spanish sewage sludge samples. This work focuses on finding statistical relations between LAS concentrations and insoluble soap in sewage sludge samples and variables related to wastewater treatment plants such as water hardness, population and treatment type. It is worth to mention that 38 samples, collected from different Spanish regions, were studied. The statistical tool we used was Principal Component Analysis (PC), in order to reduce the number of response variables. The analysis of variance (ANOVA) test and a non-parametric test such as the Kruskal-Wallis test were also studied through the estimation of the p-value (probability of obtaining a test statistic at least as extreme as the one that was actually observed, assuming that the null hypothesis is true) in order to study possible relations between the concentration of both analytes and the rest of variables. We also compared LAS and insoluble soap behaviors. In addition, the results obtained for LAS (mean value) were compared with the limit value proposed by the future Directive entitled "Working Document on Sludge". According to the results, the mean obtained for soap and LAS was 26.49 g kg(-1) and 6.15 g kg(-1) respectively. It is worth noting that LAS mean was significantly higher than the limit value (2.6 g kg(-1)). In addition, LAS and soap concentrations depend largely on water hardness. However, only LAS concentration depends on treatment type.

  13. Short Horizon Control Strategies for an Alternating Activated Sludge Process

    DEFF Research Database (Denmark)

    Isaacs, Steven Howard

    1996-01-01

    determined. The effects of the strategies on short term nitrogen dynamics are explained in terms of the potential and capacity of denitrification. The relative effectiveness of the strategies are compared and where the strategies would be located in a hierarchical control structure is discussed. Copyright (C......Three control strategies allowing improved operational flexibility of an alternating type activated sludge process are presented in a unified model based framework. The control handles employed are the addition rate of an external carbon source to denitrification, the cycle length......, and the dissolved oxygen level during aerobic periods. All three strategies attempt to satisfy a common control criterion representing optimal performance over the time length of one process cycle (typically I to 3 hours) and are based on models developed from simple mass balances or which have been experimentally...

  14. ACTIVATED SLUDGE DESIGN ON MS.EXCEL 8.0

    Directory of Open Access Journals (Sweden)

    Köksal SARICAOĞLU

    2000-01-01

    Full Text Available In this study, the planing of the Activated Sludge Method used on Environmental Engineering, was done by MS Excel 8.0, which very commonly used for spread sheet design. The program contained five sections. They are; the "DATA" section to enter the available data for calculations, the "RESULTS" section to show the outcomes of calculations, the "DETERMINATION of DIMENSIONS" section to determine the dimensions of the reactor, the "CALCULATION of AIR DIFFUSER" section to calculate the dimensions and capacity of air diffuser and the "EVALUATION" section to evaluate the results of calculations according to the criteria. The aim of this study was, to demonstrate that every engineer ca do easily needed programs related to her or his field using Excel's functions although can not know about any program language.

  15. Degradability of selected azo dye metabolites in activated sludge systems.

    Science.gov (United States)

    Ekici, P; Leupold, G; Parlar, H

    2001-08-01

    The stability of eight environmentally relevant azo dye metabolites [o-aminotoluene (2), 4,4'-thiodianiline (4), 4,4'-diaminodiphenylmethane (6), p-chloroaniline (7), 2,4-toluylenediamine (9), p-kresidine (14), 2,4-diaminoanisole (15), and 2-naphthylamine (18)] was investigated in activated sludge systems and compared to their hydrolysis stability. For both studies, test systems of the EC and EPA were used. The results show that degradation under aerobic conditions proceeds via oxidation of the substituents located on the aromatic ring or on the side chain. Under anaerobic conditions, the azo bond is reductively cleaved, which leads to the substituted amines. These are toxic and potentially hazardous to the environment.

  16. Characterization of Wastewater for Modelling of Activated Sludge Processes

    DEFF Research Database (Denmark)

    Henze, Mogens

    1992-01-01

    The fractionation of organic matter in the various parts which are used for mathematical modelling is discussed. The fractions include inert soluble, readily biodegradable, rapidly hydrolyzable, slowly hydrolyzable, biomass and inert suspended material. Methods for measuring are also discussed. F...... in a specific wastewater seem to be constant even when concentrations vary. Wastewater input to sewers and the sewer transport system significantly influences the raw wastewater composition at treatment plants........ Fractionation of biomass in wastewater and in activated sludge is difficult at present, as methods are only partly developed. Nitrogen fractions in wastewater are mainly inorganic. The organic nitrogen fractions are coupled to the organic COD fractions. The fractions of COD, biomass and nitrogen found...

  17. Selenite bioremediation potential of indigenous microorganisms from industrial activated sludge.

    Science.gov (United States)

    Garbisu, C; Alkorta, I; Carlson, D E; Leighton, T; Buchanan, B B

    1997-12-01

    Ten bacterial strains were isolated from the activated sludge waste treatment system (BIOX) at the Exxon refinery in Benicia, California. Half of these isolates could be grown in minimal medium. When tested for selenite detoxification capability, these five isolates (members of the genera Bacillus, Pseudomonas, Enterobacter and Aeromonas), were capable of detoxifying selenite with kinetics similar to those of a well characterized Bacillus subtilis strain (168 Trp+) studied previously. The selenite detoxification phenotype of the Exxon isolates was stable to repeated transfer on culture media which did not contain selenium. Microorganisms isolated from the Exxon BIOX reactor were capable of detoxifying selenite. Treatability studies using the whole BIOX microbial community were also carried out to evaluate substrates for their ability to support growth and selenite bioremediation. Under the appropriate conditions, indigenous microbial communities are capable of remediating selenite in situ.

  18. Sludge Retention Time as a Suitable Operational Parameter to Remove Both Estrogen and Nutrients in an Anaerobic-Anoxic-Aerobic Activated Sludge System.

    Science.gov (United States)

    Zeng, Qingling; Li, Yongmei; Yang, Shijia

    2013-04-01

    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.

  19. Sludge Retention Time as a Suitable Operational Parameter to Remove Both Estrogen and Nutrients in an Anaerobic–Anoxic–Aerobic Activated Sludge System

    Science.gov (United States)

    Zeng, Qingling; Li, Yongmei; Yang, Shijia

    2013-01-01

    Abstract 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. PMID:23633892

  20. Optimization of detecting hydrogenase activity for acidogenic fermentation of activated sludge

    Institute of Scientific and Technical Information of China (English)

    ZHENG Guo-chen; HE Jun-guo; LI Jian-zheng; AJAY Kumar Jha; ZHANG Li-guo

    2010-01-01

    In order to evaluate the hydrogen-producing efficiency of anaerobic activated sludge in Anaerobic Baffled Reactor(ABR)fermentation processes,the optimal conditions for hydrogen producing hydrogenase method on methyl viologen(MV)assay was used to detect the hydrogen production activity of the activated sludge.The most favorable parameters such as 0.6 mL sodium acetate buffer(pH 5.0),100 μL lysozyme,0.2 mL sodium di bromoethane(9.0 mmol/L)and 0.7 mmol/L iron added into 1 mL activated sludge(2.66~26.64 gMLVSS/L)were found.Furthermore,reaction temperature and culture time were detected as 40 ℃ and 30 min respectively.Sodium thiosulfate and sodium sulfides were taken as the reducing agent while trichloroacetic acid as terminator.Under the MV optimal conditions,micro-texic Dimethyl sulfoxide(DMSO)get higher security and better accuracy.The sensitivity of the detection methods(DMSO as electron carrier)was increased by more than30%.The results show that the optimal conditions can be applied to measure hydrogenase activity correlating with its specific hydrogen production rate in a hydrogen-producing anaerobic activated sludge system.

  1. Improving the biogas production performance of municipal waste activated sludge via disperser induced microwave disintegration.

    Science.gov (United States)

    Kavitha, S; Rajesh Banu, J; Vinoth Kumar, J; Rajkumar, M

    2016-10-01

    In this study, the influence of disperser induced microwave pretreatment was investigated to analyze the proficiency of floc disruption on subsequent disintegration and biodegradability process. Initially, the flocs in the sludge was disrupted through disperser at a specific energy input of 25.3kJ/kgTS. The upshot of the microwave disintegration presents that the solids reduction and solubilization of floc disrupted (disperser induced microwave pretreated) sludge was found to be 17.33% and 22% relatively greater than that achieved in microwave pretreated (9.3% and 16%) sludge alone. The biodegradability analysis, affords an evaluation of parameter confidence and correlation determination. The eventual biodegradability of microwave pretreated, and floc disrupted sludges were computed to be 0.15(gCOD/gCOD) and 0.28(gCOD/gCOD), respectively. An economic assessment of this study offers a positive net profit of about 104.8USD/ton of sludge in floc disrupted sample.

  2. Removal of Organic Micropollutants by Aerobic Activated Sludge

    KAUST Repository

    Wang, Nan

    2013-06-01

    The study examined the removal mechanism of non-acclimated and acclimated aerobic activated sludge for 29 target organic micropollutants (OMPs) at low concentration. The selection of the target OMPs represents a wide range of physical-chemical properties such as hydrophobicity, charge state as well as a diverse range of classes, including pharmaceuticals, personal care products and household chemicals. The removal mechanisms of OMPs include adsorption, biodegradation, hydrolysis, and vaporization. Adsorption and biodegradation were found to be the main routes for OMPs removal for all target OMPs. Target OMPs responded to the two dominant removal routes in different ways: (1) complete adsorption, (2) strong biodegradation and weak adsorption, (3) medium biodegradation and adsorption, and (4) weak sorption and weak biodegradatio. Kinetic study showed that adsorption of atenolol, mathylparaben and propylparaben well followed first-order model (R2: 0.939 to 0.999) with the rate constants ranging from 0.519-7.092 h-1. For biodegradation kinetics, it was found that benzafibrate, bisphenol A, diclofenac, gemfibrozil, ibuprofen, caffeine and DEET followed zero-order model (K0:1.15E-4 to 0.0142 μg/Lh-1, R2: 0.991 to 0.999), while TCEP, naproxen, dipehydramine, oxybenzone and sulfamethoxazole followed first-order model (K1:1.96E-4 to 0.101 h-1, R2: 0.912 to 0.996). 4 Inhibition by sodium azide (NaN3)and high temperature sterilization was compared, and it was found that high temperature sterilization will damage cells and change the sludge charge state. For the OMPs adaptation removal study, it was found that some of OMPs effluent concentration decreased, which may be due to the slow adaptation of the sludge or the increase of certain bacteria culture; some increased due to chromic toxicity of the chemicals; most of the OMPs had stable effluent concentration trend, it was explained that some of the OMPs were too difficutl to remove while other showed strong quick adaptation

  3. Coliforms removal by an integrated activated sludge-maturation pond system

    Directory of Open Access Journals (Sweden)

    Mohammad Bagher Miranzadeh

    2013-01-01

    Full Text Available Aims: This study assesses the removal of fecal indicators (i.e., total coliforms, fecal coliforms in a full-scale activated sludge and maturation pond system with primary screening facility that is operating in center of Iran. Materials and Methods: A total of 54 grab samples for microbiological test were collected from the inlet and outlet of activated sludge (AS and maturation pond (MP during the winter and summer 2010 (3 sample per month in 3 locations. Collected samples were sent to laboratory and were analyzed for total coliformbacteria (TCB and fecal coliform bacteria (FCB according to Standard Methods. Results: The results of this study show that the maximum TCB removal in AS (92.2% and MP (99.2% were occurred in summer. Also, for FCB, the highest removal rate (99.7% was recorded during the summer. The mean winter TCB numbers for AS and MP effluents were 2.7 × 10 7 and 2.3 × 10 6 (MPN per 100 ml, respectively. However, the effluent still contained a significant number of coliforms, which was greater than the permissible limit for unrestricted irrigation as prescribed by Iranian and WHO guidelines. Conclusion: Removal efficiencies of fecal indicator bacteria were maximum during summer and minimum during winter. Statistical analysis indicated that TCB and FCB removal in MP is significantly affected by ambient temperature, whereas there was weak correlation between ambient temperature and coliform removal in AS system.

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

    Science.gov (United States)

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

    2003-08-01

    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.

  5. The impact of zinc oxide nanoparticles on the bacterial microbiome of activated sludge systems

    Science.gov (United States)

    Meli, K.; Kamika, I.; Keshri, J.; Momba, M. N. B.

    2016-12-01

    The expected growth in nanomaterial applications could result in increased amounts of nanoparticles entering municipal sewer systems, eventually ending up in wastewater treatment plants and therefore negatively affecting microbial populations and biological nutrient removal. The aim of this study was to ascertain the impact of zinc oxide nanoparticles (nZnO) on the bacterial microbiome of an activated sludge system. A metagenomic approach combined with the latest generation Illumina MiSeq platform and RDP pipeline tools were used to identify and classify the bacterial microbiome of the sludge. Results revealed a drastic decrease in the number of operational taxonomic units (OTUs) from 27 737 recovered in the nZnO-free sample to 23 743, 17 733, and 13 324 OTUs in wastewater samples exposed to various concentrations of nZnO (5, 10 and 100 mg/L nZnO, respectively). These represented 12 phyla, 21 classes, 30 orders, 54 families and 51 genera, completely identified at each taxonomic level in the control samples; 7-15-25-28-20 for wastewater samples exposed to 5 mg/L nZnO; 9-15-24-31-23 for those exposed to 10 mg/L and 7-11-19-26-17 for those exposed 100 mg/L nZnO. A large number of sequences could not be assigned to specific taxa, suggesting a possibility of novel species to be discovered.

  6. Removal performance and mechanism of ibuprofen from water by catalytic ozonation using sludge-corncob activated carbon as catalyst.

    Science.gov (United States)

    Wang, Hongjuan; Zhang, Liqiu; Qi, Fei; Wang, Xue; Li, Lu; Feng, Li

    2014-09-01

    To discover the catalytic activity of sludge-corncob activated carbon in catalytic ozonation of Ibuprofen, the performance of sludge-corncob activated carbon and three selected commercial activated carbons as catalysts in catalytic ozonation was investigated. The observation indicates the degradation rate of Ibuprofen increases significantly in the presence of sludge-corncob activated carbon and the catalytic activity of sludge-corncob activated carbon is much higher than that of the other three commercial activated carbons. Ibuprofen's removal rate follows pseudo-first order kinetics model well. It is also found that the adsorption removal of Ibuprofen by sludge-corncob activated carbon is less than 30% after 40 min. And the removal efficiency of Ibuprofen in the hybrid ozone/sludge-corncob activated carbon system is higher than the sum of sludge-corncob activated carbon adsorption and ozonation alone, which is a supportive evidence for catalytic reaction. In addition, the results of radical scavenger experiments demonstrate that catalytic ozonation of Ibuprofen by sludge-corncob activated carbon follows a hydroxyl radical reaction pathway. During ozonation of Ibuprofen in the presence of activated carbon, ozone could be catalytically decomposed to form hydrogen peroxide, which can promote the formation of hydroxyl radical. The maximum amount of hydrogen peroxide occurs in the presence of sludge-corncob activated carbon, which can explain why sludge-corncob activated carbon has the best catalytic activity among four different activated carbons.

  7. THE INFLUENCE OF CALCIUM HYPOCHLORITE DOSAGE ADJUSTMENT ON TAPIOCA WASTEWATER PRE-CHLORINATION TOWARD EFFICIENCY OF ACTIVATED SLUDGE TREATMENT

    Directory of Open Access Journals (Sweden)

    Happy Mulyani

    2016-11-01

    Full Text Available The objectives of this research are to study about influence of calcium hypochlorite dosage adjustment on tapioca wastewater chlorination toward efficiency of activated sludge treatment especially at MLVSS profile and percentage of COD removal. This research mainly divided into pre-chlorination and activated sludge treatment. Pre-chlorination taken place for 60 minutes at pH 8. The variation of calcium hypochlorite dosages which used are 58, 59, and 60 mg/L. Pre-chlorination effluent with no free chlorine residual then becomes activated sludge treatment influent. Sampling has done each aeration time interval 0, 2, 4, and 6 hour for analysis of COD and MLVSS content. Research result generally shows that addition of aeration time for each variation of calcium hypochlorite dosage will increase MLVSS and decrease COD content. Smallest value of COD effluent could achieved in the activated sludge treatment with calcium hipochlorite dosage 60 mg/L addition at influent during 4 hours aeration time. Addition of 58 mg/l calcium hypochlorite results highest MLVSS and percentage of COD removal.

  8. An insight into the removal of fluoroquinolones in activated sludge process: Sorption and biodegradation characteristics.

    Science.gov (United States)

    Wang, Lu; Qiang, Zhimin; Li, Yangang; Ben, Weiwei

    2017-06-01

    The detailed sorption steps and biodegradation characteristics of fluoroquinolones (FQs) including ciprofloxacin, enrofloxacin, lomefloxacin, norfloxacin, and ofloxacin were investigated through batch experiments. The results indicate that FQs at a total concentration of 500μg/L caused little inhibition of sludge bioactivity. Sorption was the primary removal pathway of FQs in the activated sludge process, followed by biodegradation, while hydrolysis and volatilization were negligible. FQ sorption on activated sludge was a reversible process governed by surface reaction. Henry and Freundlich models could describe the FQ sorption isotherms well in the concentration range of 100-300μg/L. Thermodynamic parameters revealed that FQ sorption on activated sludge is spontaneous, exothermic, and enthalpy-driven. Hydrophobicity-independent mechanisms determined the FQ sorption affinity with activated sludge. The zwitterion of FQs had the strongest sorption affinity, followed by cation and anion, and aerobic condition facilitated FQ sorption. FQs were slowly biodegradable, with long half-lives (>100hr). FQ biodegradation was enhanced with increasing temperature and under aerobic condition, and thus was possibly achieved through co-metabolism during nitrification. This study provides an insight into the removal kinetics and mechanism of FQs in the activated sludge process, but also helps assess the environmental risks of FQs resulting from sludge disposal. Copyright © 2016. Published by Elsevier B.V.

  9. Ammonium Ion Adsorption and Settleability Improvement Achieved in a Synthetic Zeolite-Amended Activated Sludge

    Institute of Scientific and Technical Information of China (English)

    Emilia Otal; Luís F. Vilches; Yolanda Luna; Rodrigo Poblete; Juan M. García-Maya; Constantino Fernández-Pereira

    2013-01-01

    Municipal wastewater treatment plants typically exhibit two classic problems:high ammonium concen-tration in water after conventional biological treatment and, in some cases, poor activated sludge sediment ability. Potential solutions to these problems were investigated by adding a synthetic zeolite obtained from coal fly ash to different steps of activated sludge treatment. The experimental results for ammonium removal fit well with the theo-retical adsorption isotherms of the Freundlich model with a maximum adsorption capacity of 13.72 mg·g−1. Utiliza-tion of this kind of zeolite to improve activated sludge sediment ability is studied for the first time in this work. It is found that the addition of the zeolite (1 g·L−1) to an activated sludge with settling problems significantly enhances its sediment ability and compact ability. This is confirmed by the sludge volume index (SVI), which was reduced from 163 ml·g−1 to 70 ml·g−1, the V60 value, which was reduced from 894 ml·L−1 to 427 ml·L−1, and the zeta poten-tial (ζ), which was reduced from−19.81 mV to−14.29 mV. The results indicate that the addition of this synthetic zeolite to activated sludge, as an additional waste management practice, has a positive impact on both ammonium removal and sludge settleability.

  10. A new process for efficiently producing methane from waste activated sludge: alkaline pretreatment of sludge followed by treatment of fermentation liquid in an EGSB reactor.

    Science.gov (United States)

    Zhang, Dong; Chen, Yinguang; Zhao, Yuxiao; Ye, Zhengxiang

    2011-01-15

    In the literature the production of methane from waste activated sludge (WAS) was usually conducted in a continuous stirred tank reactor (CSTR) after sludge was pretreated. It was reported in our previous publication that compared with other pretreatment methods the methane production in CSTR could be significantly enhanced when sludge was pretreated by NaOH at pH 10 for 8 days. In order to further improve methane production, this study reported a new process for efficiently producing methane from sludge, that is, sludge was fermented at pH 10 for 8 days, which was adjusted by Ca(OH)(2), and then the fermentation liquid was treated in an expanded granular sludge bed (EGSB) for methane generation. First, for comparing the methane production observed in this study with that reported in the literature, the conventional operational model was applied to produce methane from the pH 10 pretreated sludge, that is, directly using the pH 10 pretreated sludge to produce methane in a CSTR. It was observed that the maximal methane production was only 0.61 m(3)CH(4)/m(3)-reactor/day. Then, the use of fermentation liquid of pH 10 pretreated sludge to produce methane in the reactors of up-flow anaerobic sludge bed (UASB), anaerobic sequencing batch reactor (ASBR) and EGSB was compared. The maximal methane production in UASB, ASBR, and EGSB reached 1.41, 3.01, and 12.43 m(3)CH(4)/m(3)-reactor/day, respectively. Finally, the mechanisms for EGSB exhibiting remarkably higher methane production were investigated by enzyme, adenosine-triphosphate (ATP), scanning electron microscope (SEM) and fluorescence in situ hybridization (FISH) analyses. It was found that the granular sludge in EGSB had the highest conversion efficiency of acetic acid to methane, and the greatest activity of hydrolysis and acidification enzymes and general physiology with much more Methanosarcinaceae.

  11. [Using Excess Activated Sludge Treated 4-Chlorophenol Contained Waste Water to Cultivate Chlorella vulgaris].

    Science.gov (United States)

    Wang, Lu; Chen, Xiu-rong; Yan, Long; He, Yi-xuan; Shi, Zhen-dong

    2015-04-01

    Using different rations of sludge extracts and supernate from 4-Chlorophenol (4-CP) simulated wastewater's excess sludge after centrifugation to cultivate the Chlorella vulgaris to achieve the goal of excess sludge utilization together with chlorella cultivating. The experiments were performed in 500 mL flasks with different rations of sludge extracts & BG-11 and supernate & BG-11 in a light growth chamber respectively. Number of algal cells, Chlorophyll, enzyme activity, oil and water total nitrogen (TN), total phosphorus (TP), total organic carbon (TOC), toxicity index were investigated. Result showed that the nutrition supplies and toxicity in the excess sludge were removed efficiently via Chlorella vulgaris, the removal rates of TN and TP were at least 40% and 90% respectively; After 10 days cultivation, the density growth of 50% sludge extracts was 20 times higher of the beginning while its chlorophyll content was lower than that of the blank group. Sludge extracts could promote the proliferation of algae, but were not conducive to the synthesis of chlorophyll. The quantity of SOD in per cell showed Chlorella vulgaris gave a positive response via stimulation from toxicant in sludge extracts and supernate. The best time for collecting chlorella vulgaris was the fifth day of cultivation, taking neutral oil accumulation as the evaluating indicator for its utilization combined with the removal of supplies and toxicity.

  12. Influence of copper nanoparticles on the physical-chemical properties of activated sludge.

    Science.gov (United States)

    Chen, Hong; Zheng, Xiong; Chen, Yinguang; Li, Mu; Liu, Kun; Li, Xiang

    2014-01-01

    The physical-chemical properties of activated sludge, such as flocculating ability, hydrophobicity, surface charge, settleability, dewaterability and bacteria extracellular polymer substances (EPS), play vital roles in the normal operation of wastewater treatment plants (WWTPs). The nanoparticles released from commercial products will enter WWTPs and can induce potential adverse effects on activated sludge. This paper focused on the effects of copper nanoparticles (CuNPs) on these specific physical-chemical properties of activated sludge. It was found that most of these properties were unaffected by the exposure to lower CuNPs concentration (5 ppm), but different observation were made at higher CuNPs concentrations (30 and 50 ppm). At the higher CuNPs concentrations, the sludge surface charge increased and the hydrophobicity decreased, which were attributed to more Cu2+ ions released from the CuNPs. The carbohydrate content of EPS was enhanced to defense the toxicity of CuNPs. The flocculating ability was found to be deteriorated due to the increased cell surface charge, the decreased hydrophobicity, and the damaged cell membrane. The worsened flocculating ability made the sludge flocs more dispersed, which further increased the toxicity of the CuNPs by increasing the availability of the CuNPs to the bacteria present in the sludge. Further investigation indicated that the phosphorus removal efficiency decreased at higher CuNPs concentrations, which was consistent with the deteriorated physical-chemical properties of activated sludge. It seems that the physical-chemical properties can be used as an indicator for determining CuNPs toxicity to the bacteria in activated sludge. This work is important because bacteria toxicity effects to the activated sludge caused by nanoparticles may lead to the deteriorated treatment efficiency of wastewater treatment, and it is therefore necessary to find an easy way to indicate this toxicity.

  13. STABILIZATION OF ACTIVE SLUDGE AFTER WASTEWATER TREATMENT CONTAMINATED BY PETROLEUM PRODUCTS

    Directory of Open Access Journals (Sweden)

    Olena Semenova

    2016-06-01

    Full Text Available Purpose: Biochemical purification of wastewater containing refined petroleum products takes place due to the oxidation of pollutants by active sludge organisms. As a result of this process the intense consumption of pollutants by active sludge and its growth occurs. Therefore, the possibility to use active sludge containing refined petroleum products after wastewater treatment requires its stabilization. Methods: In this work the oxidation by a 30% hydrogen peroxide solution was studied for its use as a stabilizer. Chemical oxidizers, including hydrogen peroxide destroy organic polymers retaining free water thus promoting water release from the structure of sludge particles. On the other hand remains of fine structured oxidized biopolymers can lead to filter clogging, that is, reduce moisture exchange of sludge. Results: The experiment was carried out to find out the correlation between the doses of hydrogen peroxide and the resistivity value of sludge filtration. Discussion: Stabilized active sludge can be used as a fuel for boiler rooms, which in its turn will reduce natural gas consumption for the enterprise needs.

  14. Sludge reduction by predatory activity of aquatic oligochaetes in wastewater treatment plants: Science or fiction? A review

    NARCIS (Netherlands)

    Ratsak, C.H.; Verkuijlen, J.

    2006-01-01

    Biological aerobic wastewater treatment plants (WWTPs) produce a lot of excess sludge. The costs for handling this residual product are increasing, so the search for alternative techniques to reduce the amount of sludge has to be continued. Activated sludge consists of inorganic and organic substanc

  15. Metaproteomics of activated sludge from a wastewater treatment plant - a pilot study.

    Science.gov (United States)

    Püttker, Sebastian; Kohrs, Fabian; Benndorf, Dirk; Heyer, Robert; Rapp, Erdmann; Reichl, Udo

    2015-10-01

    In this study, the impact of protein fractionation techniques prior to LC/MS analysis was investigated on activated sludge samples derived at winter and summer condition from a full-scale wastewater treatment plant (WWTP). For reduction of the sample complexity, different fractionation techniques including RP-LC (1D-approach), SDS-PAGE and RP-LC (2D-approach) as well as RP-LC, SDS-PAGE and liquid IEF (3D-approach) were carried out before subsequent ion trap MS analysis. The derived spectra were identified by MASCOT search using a combination of the public UniProtKB/Swiss-Prot protein database and metagenome data from a WWTP. The results showed a significant increase of identified spectra, enabled by applying IEF and SDS-PAGE to the proteomic workflow. Based on meta-proteins, a core metaproteome and a corresponding taxonomic profile of the wastewater activated sludge were described. Functional aspects were analyzed using the KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway library by plotting KEGG Orthology identifiers (KO numbers) of protein hits into pathway maps of the central carbon (map01200) and nitrogen metabolism (map00910). Using the 3D-approach, most proteins involved in glycolysis and citrate cycle and nearly all proteins of the nitrogen removal were identified, qualifying this approach as most promising for future studies. All MS data have been deposited in the ProteomeXchange with identifier PXD001547 (http://proteomecentral.proteomexchange.org/dataset/PXD001547).

  16. Relationship between protozoan and metazoan communities and operation and performance parameters in a textile sewage activated sludge system.

    Science.gov (United States)

    Araújo dos Santos, Liliana; Ferreira, Vânia; Pereira, Maria Olívia; Nicolau, Ana

    2014-08-01

    The present study aims at investigating the possibility of assessing performance and depuration conditions of an activated sludge wastewater treatment plant through an exploration of the microfauna. The plant, receiving textile industrial (70%) and domestic (30%) sewage, consists of a two-step biological depurating plant, with activated sludge followed by a percolating system. A total of 35 samples were analyzed during five months, and 30 taxa of protozoa and small metazoa were found. Epistylis rotans, Vorticella microstoma, Aspidisca cicada and Arcella sp. were the most frequent protozoa identified. Several significant correlations between biological, physical-chemical and operational parameters were determined, but no significant correlations could be established between biological parameters and removal efficiencies. The Sludge Biotic Index (SBI) reflected the overall state of the community but only presented statistically significant correlations with the influent total suspended solids (TSS), total suspended solids in mixed-liquor (MLTSS) and dissolved oxygen (DO). The determination of key groups and taxa along with general community parameters showed to have potential value as indicators of the depuration conditions. Despite the impossibility of correlating biological parameters and the removal efficiencies, the present study attests the value of the microfauna to assess the operation of the activated sludge systems even in the case of non-conventional plants and/or plants receiving industrial sewage.

  17. Enhancing filterability of activated sludge from landfill leachate treatment plant by applying electrical field ineffective on bacterial life.

    Science.gov (United States)

    Akkaya, Gulizar Kurtoglu; Sekman, Elif; Top, Selin; Sagir, Ece; Bilgili, Mehmet Sinan; Guvenc, Senem Yazici

    2017-03-09

    The aim of this study is to investigate filterability enhancement of activated sludge supplied form a full-scale leachate treatment plant by applying DC electric field while keeping the biological operational conditions in desirable range. The activated sludge samples were received from the nitrification tank in the leachate treatment plant of Istanbul's Odayeri Sanitary Landfill Site. Experimental sets were conducted as laboratory-scale batch studies and were duplicated for 1A, 2A, 3A, 4A, and 5A of electrical currents and 2, 5, 10, 15, and 30 min of exposure times under continuous aeration. Physicochemical parameters such as temperature, pH, and oxidation reduction potential in the mixture right after each experimental set and biochemical parameters such as chemical oxygen demand, total phosphorus, and ammonia nitrogen in supernatant were analyzed to define the sets that remain in the range of ideal biological operational conditions. Later on, sludge filterability properties such as capillary suction time, specific resistance to filtration, zeta potential, and particle size were measured for remaining harmless sets. Additionally, cost analyses were conducted in respect to energy and electrode consumptions. Application of 2A DC electric field and 15-min exposure time was found to be the most favorable conditions to enhance filterability of the landfill leachate-activated sludge.

  18. Microbial Community Structure of Activated Sludge for Biosolubilization of Two Different Rock Phosphates.

    Science.gov (United States)

    Xiao, Chunqiao; Wu, Xiaoyan; Liu, Tingting; Xu, Guang; Chi, Ruan

    2016-12-16

    A microbial consortium was directly taken from activated sludge and was used to solubilize rock phosphates (RPs) in a lab-scale bioreactor in this study. Results showed that the microbial consortium could efficiently release soluble phosphorus (P) from the RPs, and during 30-day incubation, it grew well in the bioreactor and reduced the pH of the solutions. The biosolubilization process was also illustrated by the observation of scanning electron microscopy combined with an energy dispersive X-ray spectroscopy (SEM-EDX), which showed an obvious corrosion on the ore surfaces, and most elements were removed from the ore samples. The analysis of microbial community structure by Illumina 16S ribosomal RNA (rRNA) gene and 18S rRNA gene MiSeq sequencing reflected different microbial diversity and richness in the solutions added with different ore samples. A lower richness and diversity of bacteria but a higher richness and diversity of fungi occurred in the solution added with ore sample 1 compared to that of in the solution added with ore sample 2. Alphaproteobacteria and Saccharomycetes were the dominating bacterial and fungal group, respectively, both in the solutions added with ore samples 1 and 2 at the class level. However, their abundances in the solution added with ore sample 1 were obviously lower than that in the solution added with ore sample 2. This study provides new insights into our understanding of the microbial community structure in the biosolubilization of RPs by a microbial consortium directly taken from activated sludge.

  19. Comparison of the Modeling Approach between Membrane Bioreactor and Conventional Activated Sludge Processes

    DEFF Research Database (Denmark)

    Jiang, Tao; Sin, Gürkan; Spanjers, Henri

    2009-01-01

    Activated sludge models (ASM) have been developed and largely applied in conventional activated sludge (CAS) systems. The applicability of ASM to model membrane bioreactors (MBR) and the differences in modeling approaches have not been studied in detail. A laboratory-scale MBR was modeled using ASM...... to the inhibition effect of soluble microbial products (SMP) at elevated concentration. Second, a greater biomass affinity to oxygen and ammonium was found, which was probably related to smaller MBR sludge flocs. Finally, the membrane throughput during membrane backwashing/relaxation can be normalized...

  20. Inhibitory effect of ammonia nitrogen on specific methanogenic activity of anaerobic granular sludge

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A series of batch experiments were conducted in 125 mL serum bottles to assess the toxicity of different concentrations of ammonia nitrogen to the specific methanogenic activity of anaerobic granular sludge from upflow anaerobic sludge bed(UASB) and expanded granular sludge bed(EGSB) reactors. The effects of pH value and temperature on toxicity of ammonia nitrogen to anaerobes were investigated. The results show that the specific methanogenic activity of anaerobic granular sludge suffers inhibition from ammonia nitrogen, the concentrations of ammonia nitrogen that produce 50% inhibition of specific methanogenic activity for sludge from UASB and EGSB reactor are 2.35 and 2.75 g/L, respectively. Hydrogen utilizing methanogens suffers less inhibition from ammonia nitrogen than that of acetate utilizing methanogens. Hydrogen-producing acetogens that utilize propionate and butyrate as substrates suffer serious inhibition from ammonia nitrogen. The toxicity of ammonia nitrogen to anaerobic granular sludge enhances when pH value and temperature increase. Anaerobic granular sludge can bear higher concentrations of ammonia nitrogen after being acclimated by ammonia nitrogen for 7 d.

  1. Removal of Cu(II from Aqueous Solutions using Dried Activated Sludge and Dried Activated Nano-Sludge: Adsorption on a Fixed-Bed Column

    Directory of Open Access Journals (Sweden)

    Zahra Ahmari

    2015-06-01

    Full Text Available In the present time study,dried activated sludge(DAS and dried activated nano sludge(DANS was used for the removal of Cu(II from aqueous solution in a fixed-bed reactor. The effect of important parameters including the flow rate and bed height were examined. Dried activated nano sludge column regeneration using 1 M concentration of HNO3 has been studied.The Thomas model was used for the mathematical description of the adsorption of Copper at different flow rate and various bed height to determine parameters of the column suitable for process design. Both exhaustion time and breakthrough time increased with increasing bed height, while the adsorption bed capacity decreased as the flow rate increased.

  2. Inhibition of total oxygen uptake by silica nanoparticles in activated sludge

    Energy Technology Data Exchange (ETDEWEB)

    Sibag, Mark [Department of Environment and Energy, Sejong University, 98 Gunja-Dong, Gwangjin-Gu, Seoul 143-747 (Korea, Republic of); Choi, Byeong-Gyu [School of Civil, Environmental and Architectural Engineering, Korea University, 145, Anam-ro, Sungbuk-ku, Seoul 136-701 (Korea, Republic of); Suh, Changwon [Energy Lab, Environment Group, Samsung Advanced Institute of Technology, 130 Samsung-ro, Yeongtong-gu, Suwon-si, Gyeonggi-do 443-803 (Korea, Republic of); Lee, Kwan Hyung; Lee, Jae Woo [Department of Environmental Engineering and Program in Environmental Technology and Policy, Korea University, Sejong 339-700 (Korea, Republic of); Maeng, Sung Kyu [Department of Civil and Environmental Engineering, Sejong University, 98 Gunja-Dong, Gwangjin-Gu, Seoul 143-747 (Korea, Republic of); Cho, Jinwoo, E-mail: jinwoocho@sejong.edu [Department of Environment and Energy, Sejong University, 98 Gunja-Dong, Gwangjin-Gu, Seoul 143-747 (Korea, Republic of)

    2015-02-11

    Highlights: • Silica nanoparticles (SNP) inhibit total oxygen uptake in activated sludge. • Relatively smaller SNP are inhibitorier than larger SNP. • SNP alters C15:0, C16:0 and C18:0 in activated sludge fatty acid methyl ester profile. - Abstract: Nanoparticle toxicity to biological activities in activated sludge is largely unknown. Among the widely used nanoparticles, silica nanoparticles (SNP) have a limited number of studies associated with inhibition to the activated sludge process (ASP). We demonstrated SNP inhibition of activated sludge respiration through oxygen uptake rate (OUR) measurement. Based on the percentage inhibition of total oxygen consumption (I{sub T}), we observed that smaller SNPs (12 nm, I{sub T} = 33 ± 3%; 151 nm, I{sub T} = 23 ± 2%) were stronger inhibitors than larger SNPs (442 and 683 nm, I{sub T} = 5 ± 1%). Transmission electron micrographs showed that some of the SNPs were adsorbed on and/or apparently embedded somewhere in the microbial cell membrane. Whether SNPs are directly associated with the inhibition of total oxygen uptake warrants further studies. However, it is clear that SNPs statistically significantly altered the composition of microbial membrane lipids, which was more clearly described by principal component analysis and weighted Euclidian distance (PCA-ED) of the fatty acid methyl ester (FAME) data. This study suggests that SNPs potentially affect the biological activity in activated sludge through the inhibition of total oxygen uptake.

  3. Effects of activated sludge flocs and pellets seeds on aerobic granule properties

    Institute of Scientific and Technical Information of China (English)

    Huacheng Xu; Pinjing He; Guanzhao Wang; Liming Shao

    2011-01-01

    Aerobic granules seeded with activated sludge fiocs and pellets (obtained from activated sludge flocs) were cultivated in two sequencing batch reactors and their characteristics were compared.Compared with granules seeded with activated sludge flocs, those seeded with pellets had shorter start-up time, larger diameter, better chemical oxygen demand removal efficiency, and higher hydrophobicity, suspended solid concentration, and Mg2+ content.The different inocula led the granule surface with different microbial morphologies, but did not result in different distribution patterns of extracellular polymeric substances and cells.The anaerobic bacterium Anoxybacillus sp.was detected in the granules seeded with pellets.These results highlighted the advantage of pellet over activated sludge floc as the seed for aerobic granulation and wastewater treatment.

  4. Comparison of bacterial communities of conventional and A-stage activated sludge systems

    NARCIS (Netherlands)

    Gonzalez-Martinez, A.; Rodriguez-Sanchez, A.; Lotti, T.; Garcia-Ruiz, M.J.; Gonzalez-Lopez, J.; Van Loosdrecht, M.C.M.

    2016-01-01

    The bacterial community structure of 10 different wastewater treatment systems and their influents has been investigated through pyrosequencing, yielding a total of 283486 reads. These bioreactors had different technological configurations: conventional activated sludge (CAS) systems and very highly

  5. Batch system for study of Cr(VI) Bio sorption by dried waste activated sludge

    Energy Technology Data Exchange (ETDEWEB)

    Farzadkia, M.; Gholami, M.; Darvishi Cheshmeh Soltani, R.; Yaghmaeian, K.; Shams Khorramabadi, G.

    2009-07-01

    Activated sludge from wastewater treatment systems contains both bacteria and protozoa. The cell wall of bacteria essentially consists of various compounds, such as carboxyl, acidic polysaccharides,lipids, amino acids and other components. (Author)

  6. Factors influencing sorption of ciprofloxacin onto activated sludge: Experimental assessment and modelling implications

    DEFF Research Database (Denmark)

    Polesel, Fabio; Lehnberg, Kai; Dott, Wolfgang;

    2015-01-01

    Many of the pharmaceuticals and personal care products occurring in municipal sewage are ionizing substances, and their partitioning behaviour is affected by ionic interactions with solid matrices. In activated sludge systems, such interactions have currently not been adequately understood...

  7. Improved computational model (AQUIFAS) for activated sludge, integrated fixed-film activated sludge, and moving-bed biofilm reactor systems, Part I: Semi-empirical model development.

    Science.gov (United States)

    Sen, Dipankar; Randall, Clifford W

    2008-05-01

    Research was undertaken to develop a model for activated sludge, integrated fixed-film activated sludge (IFAS), and moving-bed biofilm reactor (MBBR) systems. The model can operate with up to 12 cells (reactors) in series, with biofilm media incorporated to one or more cells, except the anaerobic cells. The process configuration can be any combination of anaerobic, anoxic, aerobic, post-anoxic with or without supplemental carbon, and reaeration; it can also include any combination of step feed and recycles, including recycles for mixed liquor, return activated sludge, nitrates, and membrane bioreactors. This paper presents the structure of the model. The model embeds a biofilm model into a multicell activated sludge model. The biofilm flux rates for organics, nutrients, and biomass can be computed by two methods--a semi-empirical model of the biofilm that is relatively simpler, or a diffusional model that is computationally intensive. The values of the kinetic parameters for the model were measured using pilot-scale activated sludge, IFAS, and MBBR systems. For the semiempirical version, a series of Monod equations were developed for chemical oxygen demand, ammonium-nitrogen, and oxidized-nitrogen fluxes to the biofilm. Within the equations, a second Monod expression is used to simulate the effect of changes in biofilm thickness and fraction nitrifiers in the biofilm. The biofilm flux model is then linked to the activated sludge model. The diffusional model and the verification of the models are presented in subsequent papers (Sen and Randall, 2008a, 2008b). The model can be used to quantify the amount of media and surface area required to achieve nitrification, identify the best locations for the media, and optimize the dissolved oxygen levels and nitrate recycle rates. Some of the advanced features include the ability to apply different media types and fill fractions in cells; quantify nitrification, denitrification, and biomass production in the biofilm and

  8. Activated-sludge nitrification in the presence of linear and branched-chain alkyl benzene sulfonates.

    Science.gov (United States)

    Baillod, C R; Boyle, W C

    1968-01-01

    The effects of biodegradable linear alkyl benzene sulfonate and branched-chain alkyl benzene sulfonate detergents on activated-sludge nitrification were investigated by administering a synthetic waste containing up to 23 mg of each detergent per liter to eight bench-scale, batch, activated-sludge units. It was found that both detergents tended to promote complete oxidation of ammonia to nitrate, whereas control units produced approximately equal amounts of nitrite and nitrate. Various hypotheses are offered to explain the phenomenon.

  9. Enhanced anaerobic digestion of waste activated sludge digestion by the addition of zero valent iron.

    Science.gov (United States)

    Feng, Yinghong; Zhang, Yaobin; Quan, Xie; Chen, Suo

    2014-04-01

    Anaerobic digestion is promising technology to recover energy from waste activated sludge. However, the sludge digestion is limited by its low efficiency of hydrolysis-acidification. Zero valent iron (ZVI) as a reducing material is expected to enhance anaerobic process including the hydrolysis-acidification process. Considering that, ZVI was added into an anaerobic sludge digestion system to accelerate the sludge digestion in this study. The results indicated that ZVI effectively enhanced the decomposition of protein and cellulose, the two main components of the sludge. Compared to the control test without ZVI, the degradation of protein increased 21.9% and the volatile fatty acids production increased 37.3% with adding ZVI. More acetate and less propionate are found during the hydrolysis-acidification with ZVI. The activities of several key enzymes in the hydrolysis and acidification increased 0.6-1 time. ZVI made the methane production raise 43.5% and sludge reduction ratio increase 12.2 percent points. Fluorescence in situ hybridization analysis showed that the abundances of hydrogen-consuming microorganisms including homoacetogens and hydrogenotrophic methanogens with ZVI were higher than the control, which reduced the H2 accumulation to create a beneficial condition for the sludge digestion in thermodynamics. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Effect of humic acid in leachate on specific methanogenic activity of anaerobic granular sludge.

    Science.gov (United States)

    Guo, Mengfei; Xian, Ping; Yang, Longhui; Liu, Xi; Zhan, Longhui; Bu, Guanghui

    2015-01-01

    In order to find out the effects of humic acid (HA) in anaerobic-treated landfill leachate on granular sludge, the anaerobic biodegradability of HA as well as the influences of HA on the total cumulative methane production, the anaerobic methanization process and the specific methanogenic activity (SMA) of granular sludge are studied in this paper. Experimental results show that as a non-biodegradable organic pollutant, HA is also difficult to be decomposed by microbes in the anaerobic reaction process. Presence of HA and changes in the concentration have no significant influences on the total cumulative methane production and the anaerobic methanization process of granular sludge. Besides, the total cumulative methane production cannot reflect the inhibition of toxics on the methanogenic activity of granular sludge on the premise of sufficient reaction time. Results also show that HA plays a promoting role on SMA of granular sludge. Without buffering agent the SMA value increased by 19.2% on average due to the buffering and regulating ability of HA, while with buffering agent the SMA value increased by 5.4% on average due to the retaining effect of HA on the morphology of the sludge particles. However, in the presence of leachate the SMA value decreased by 27.6% on average, because the toxic effect of the toxics in the leachate on granular sludge is much larger than the promoting effect of HA.

  11. Wastewater treatment--adsorption of organic micropollutants on activated HTC-carbon derived from sewage sludge.

    Science.gov (United States)

    Kirschhöfer, Frank; Sahin, Olga; Becker, Gero C; Meffert, Florian; Nusser, Michael; Anderer, Gilbert; Kusche, Stepan; Klaeusli, Thomas; Kruse, Andrea; Brenner-Weiss, Gerald

    2016-01-01

    Organic micropollutants (MPs), in particular xenobiotics and their transformation products, have been detected in the aquatic environment and the main sources of these MPs are wastewater treatment plants. Therefore, an additional cleaning step is necessary. The use of activated carbon (AC) is one approach to providing this additional cleaning. Industrial AC derived from different carbonaceous materials is predominantly produced in low-income countries by polluting processes. In contrast, AC derived from sewage sludge by hydrothermal carbonization (HTC) is a regional and sustainable alternative, based on waste material. Our experiments demonstrate that the HTC-AC from sewage sludge was able to remove most of the applied MPs. In fact more than 50% of sulfamethoxazole, diclofenac and bezafibrate were removed from artificial water samples. With the same approach carbamazepine was eliminated to nearly 70% and atrazine more than 80%. In addition a pre-treated (phosphorus-reduced) HTC-AC was able to eliminate 80% of carbamazepine and diclofenac. Atrazine, sulfamethoxazole and bezafibrate were removed to more than 90%. Experiments using real wastewater samples with high organic content (11.1 g m(-3)) succeeded in proving the adsorption capability of phosphorus-reduced HTC-AC.

  12. The activated sludge bulking filament Eikelboom morphotype 0914 is a member of the Chloroflexi.

    Science.gov (United States)

    Speirs, Lachlan B M; McIlroy, Simon J; Petrovski, Steve; Seviour, Robert J

    2011-04-01

    The filamentous bacterium Eikelboom morphotype type 0914 responsible for bulking in activated sludge plants is identified here for the first time as a member of the phylum Chloroflexi subgroup 1. Two FISH probes, CFX67a and CFX67b, targeting the 16S rRNA sequences of this filament morphotype were designed, validated and used successfully for its in situ identification. A survey of plants in eastern Australia with the CFX67a probe showed it targeted only the type 0914 morphotype that was common especially in long sludge age plants designed to remove phosphorus and nitrogen microbiologically, although being in very low abundance in many samples. Filaments responding to the CFX67b probe also exhibited the type 0914 morphology but were less frequent, although again occurring in similarly configured plants. All these filaments showed an uneven FISH signal suggesting their ribosomes are localized at the ends of their cells. Furthermore, some generated distinctive FISH signals in all biomass samples containing them, where only certain cells within any single trichome fluoresced with probes designed against different target sites. Helper probes for each of these were required before all cells fluoresced above the visual detection limits of FISH.

  13. Date palm and the activated sludge co-composting actinobacteria sanitization potential.

    Science.gov (United States)

    El Fels, Loubna; Hafidi, Mohamed; Ouhdouch, Yedir

    2016-01-01

    The objective of this study was to find a connection between the development of the compost actinobacteria and the potential involvement of antagonistic thermophilic actinomycetes in compost sanitization as high temperature additional role. An abundance of actinobacteria and coliforms during the activated sludge and date palm co-composting is determined. Hundred actinomycete isolates were isolated from the sample collected at different composting times. To evaluate the antagonistic effects of the different recovered actinomycete isolates, several wastewater-linked microorganisms known as human and plant potential pathogens were used. The results showed that 12 isolates have an in vitro inhibitory effect on at least 9 of the indicator microorganisms while only 4 active strains inhibit all these pathogens. The antimicrobial activities of sterilized composting time extracts are also investigated.

  14. Ultrasonic waste activated sludge disintegration for recovering multiple nutrients for biofuel production.

    Science.gov (United States)

    Xie, Guo-Jun; Liu, Bing-Feng; Wang, Qilin; Ding, Jie; Ren, Nan-Qi

    2016-04-15

    Waste activated sludge is a valuable resource containing multiple nutrients, but is currently treated and disposed of as an important source of pollution. In this work, waste activated sludge after ultrasound pretreatment was reused as multiple nutrients for biofuel production. The nutrients trapped in sludge floc were transferred into liquid medium by ultrasonic disintegration during first 30 min, while further increase of pretreatment time only resulted in slight increase of nutrients release. Hydrogen production by Ethanoligenens harbinense B49 from glucose significantly increased with the concentration of ultrasonic sludge, and reached maximum yield of 1.97 mol H2/mol glucose at sludge concentration of 7.75 g volatile suspended solids/l. Without addition of any other chemicals, waste molasses rich in carbohydrate was efficiently turned into hydrogen with yield of 189.34 ml H2/g total sugar by E. harbinense B49 using ultrasonic sludge as nutrients. The results also showed that hydrogen production using pretreated sludge as multiple nutrients was higher than those using standard nutrients. Acetic acid produced by E. harbinense B49 together with the residual nutrients in the liquid medium were further converted into hydrogen (271.36 ml H2/g total sugar) by Rhodopseudomonas faecalis RLD-53 through photo fermentation, while ethanol was the sole end product with yield of 220.26 mg/g total sugar. Thus, pretreated sludge was an efficient nutrients source for biofuel production, which could replace the standard nutrients. This research provided a novel strategy to achieve environmental friendly sludge disposal and simultaneous efficient biofuel recovery from organic waste.

  15. Effect of Salinity Variations on the Performance of Activated Sludge System

    Institute of Scientific and Technical Information of China (English)

    JIAN-LONG WANG; XIN-MIN ZHAN; YE-CHENG FENG; YI QIAN

    2005-01-01

    Objective To investigate the influence of salinity variations on the performance of activated sludge systems, treating domestic wastewater. Methods The completely mixed reactor was used and operated in a batch-wise mode. The activated sludge taken from the Gaobeidian Wastewater Treatment Plant was used as a seeding sludge. Total organic carbon (TOC), oxygen uptake rate (OUR) and suspended solids (SS) were used as parameters to characterize the performance of the treatment systems. TOC was measured using a TOC-analyzer (TOC-5000, Japan). The OUR value was measured with a dissolved oxygen meter (YSI model-58). SS was measured gravimetrically. Results The TOC removal efficiency and the OUR value of activated sludge were not deteriorated when the NaCl shock concentration was less than 0.5 g/L. However, when the NaCl shock concentrations were up to 10g/L and 20 g/L, the OUR of activated sludge was reduced by 35% and TOC removal efficiency was dropped by 30%, compared with the control experiment without NaCl shock loading. Conclusion The effect of NaCl shock loading on the activated sludge wastewater treatment system is dependant upon the NaCl concentrations and the degree of influence can be inferred through the change of substrate utilization rate at different shock NaCl loadings.

  16. A hundred years of activated sludge: time for a rethink

    Directory of Open Access Journals (Sweden)

    Abdul Rahiman Sheik

    2014-03-01

    Full Text Available Biological wastewater treatment plants (BWWTPs based on the activated sludge (AS process have dramatically improved worldwide water sanitation despite increased urbanization and industrialization. However, current AS-based operations are considered economically and environmentally unsustainable. In this Perspective, we discuss our current understanding of microbial populations and their metabolic transformations in AS-based BWWTPs in view of developing more sustainable processes in the future. In particular, much has been learned over the course of the past 25 years about specialized microorganisms, which could be more comprehensively leveraged to recover energy and/or nutrients from wastewater streams. To achieve this, we propose a bottom-up design approach, focused around the concept of a wastewater biorefinery column, which would rely on the engineering of distinct ecological niches into a BWWTP in order to guarantee the targeted enrichment of specific organismal groups which in turn will allow the harvest of high-value resources from wastewater. This concept could be seen as a possible grand challenge to microbial ecologists and engineers alike at the centenary of the discovery of the AS process.

  17. Modeling organic nitrogen conversions in activated sludge bioreactors.

    Science.gov (United States)

    Makinia, Jacek; Pagilla, Krishna; Czerwionka, Krzysztof; Stensel, H David

    2011-01-01

    For biological nutrient removal (BNR) systems designed to maximize nitrogen removal, the effluent total nitrogen (TN) concentration may range from 2.0 to 4.0 g N/m(3) with about 25-50% in the form of organic nitrogen (ON). In this study, current approaches to modeling organic N conversions (separate processes vs. constant contents of organic fractions) were compared. A new conceptual model of ON conversions was developed and combined with Activated Sludge Model No. 2d (ASM2d). The model addresses a new insight into the processes of ammonification, biomass decay and hydrolysis of particulate and colloidal ON (PON and CON, respectively). Three major ON fractions incorporated are defined as dissolved (DON) (model parameter set, the behaviors of both inorganic N forms (NH4-N, NOX-N) and ON forms (DON, CON) in the batch experiments were predicted. The challenges to accurately simulate and predict effluent ON levels from BNR systems are due to analytical methods of direct ON measurement (replacing TKN) and lack of large enough database (in-process measurements, dynamic variations of the ON concentrations) which can be used to determine parameter value ranges.

  18. [Study on dewatering of activated sludge under applied electric field].

    Science.gov (United States)

    Ji, Xue-Yuan; Wang, Yi-Li; Feng, Jing

    2012-12-01

    For an electro-dewatering process of activated sludge (AS), the effect of pH and conductivity of AS, flocculation conditioning and operation factors of horizontal electric field (voltage magnitude, method of applying electric field and distance between plates) were investigated, and the corresponding optimum electro-dewatering conditions were also obtained. The results showed that the best electro-dewatering effect was achieved for AS without change of its pH value (6.93) and conductivity (1.46 mS x cm(-1)). CPAM conditioning could lead to the increase of 30%-40% in the dewatering rate and accelerate the dewatering process, whereas a slight increase in the electro-dewatering rate. The electro-dewatering rate for conditioned AS reached 83.12% during an electric field applied period of 60 minutes, while this rate for original AS could be 75.31% even the electric field applied period extended to 120 minutes. The delay of applying the electric field had an inhibition effect on the AS electro-dewatering rate. Moreover, the optimum conditions for AS electro-dewatering were followed: CPAM dose of 9 g x kg(-1), electric field strength of 600 V x m(-1), distance between the two plates of 40 mm, dehydration time of 60 minutes. Under above optimum conditions the AS electro-dewatering rate could approach to 85.33% and the moisture content in AS decreased from 99.30% to 95.15% accordingly.

  19. The influence of hydrolysis induced biopolymers from recycled aerobic sludge on specific methanogenic activity and sludge filterability in an anaerobic membrane bioreactor.

    Science.gov (United States)

    Buntner, D; Spanjers, H; van Lier, J B

    2014-03-15

    The objective of the present study was to evaluate the impact of excess aerobic sludge on the specific methanogenic activity (SMA), in order to establish the maximum allowable aerobic sludge loading. In batch tests, different ratios of aerobic sludge to anaerobic inoculum were used, i.e. 0.03, 0.05, 0.10 and 0.15, showing that low ratios led to an increased SMA. However, the ratio 0.15 caused more than 20% SMA decrease. In addition to the SMA tests, the potential influence of biopolymers and extracellular substances, that are generated as a result of excess aerobic sludge hydrolysis, on membrane performance was determined by assessing the fouling potential of the liquid broth, taking into account parameters such as specific resistance to filtration (SRF) and supernatant filterability (SF). Addition of aerobic sludge to the anaerobic biomass resulted in a high membrane fouling potential. The increase in biopolymers could be ascribed to aerobic sludge hydrolysis. A clear positive correlation between the concentration of the colloidal fraction of biopolymer clusters (cBPC) and the SRF was observed and a negative correlation between the cBPC and the SF measured at the end of the above described SMA tests. The latter implies that sludge filtration resistance increases when more aerobic sludge is hydrolyzed, and thus more cBPC is released. During AnMBR operation, proteins significantly contributed to sludge filterability decrease expressed as SRF and SF, whereas the carbohydrate fraction of SMP was of less importance due to low concentrations. On the contrary, carbohydrates seemed to improve filterability and diminish SRF of the sludge. Albeit, cBPC increase caused an increase in mean TMP during the AnMBR operation, confirming that cBPC is positively correlated to membrane fouling.

  20. Iron and phosphorus speciation in Fe-conditioned membrane bioreactor activated sludge.

    Science.gov (United States)

    Wu, Hao; Ikeda-Ohno, Atsushi; Wang, Yuan; Waite, T David

    2015-06-01

    Iron dosing of membrane bioreactors (MBRs) is widely used as a means of meeting effluent phosphorus targets but there is limited understanding of the nature of iron and phosphorus-containing solids that are formed within the bioreactor (an important issue in view of the increasing interest in recovering phosphorus from wastewaters). Of particular challenge is the complexity of the MBR system and the variety of reactions that can occur on addition of iron salts to a membrane bioreactor. In this study, the performances of bench scale MBRs with dosing of either ferrous or ferric salts were monitored for a period of four months. The distributions of Fe and P-species in the Fe-conditioned sludges were determined using X-ray absorption spectroscopy (XAS) at the Fe K-edge and the P K-edge. Regardless of whether iron was dosed to the anoxic or aerobic chambers and regardless of whether ferrous (Fe(II)) or ferric (Fe(III)) iron was dosed, iron present in the minerals in the conditioned sludges was consistently in the +III oxidation state. Fitting of the Fe K-edge EXAFS spectra revealed that an Fe(III)-phosphate species was the main Fe species present in all cases with the remaining fraction dominated by lepidocrocite (γ-FeOOH) in the Fe(II)-dosed case and ferrihydrite (am-FeOOH) in the Fe(III)-dosed case. Approximately half the phosphorus in the activated sludge samples was present as a distinct Fe-PO4 mineral (such as strengite or an amorphous ferric hydroxyl phosphate analogue of strengite) and half as phosphorus adsorbed to an iron oxyhydroxide mineral phase indicating that both co-precipitation and adsorption of phosphorus by iron contribute to removal of phosphorus from the MBR supernatant.

  1. The activated sludge bulking filament Eikelboom morphotype 0803 embraces more than one member of the Chloroflexi.

    Science.gov (United States)

    Speirs, Lachlan B M; Tucci, Joseph; Seviour, Robert J

    2015-09-01

    The Eikelboom filamentous morphotype 0803 is commonly found in activated sludge systems globally, where it contributes to sludge bulking events. Earlier reports have suggested that it is a member of both the Proteobacteria and Chloroflexi. This study shows that this filament contributing to a period of poor sludge settleability in an Australian activated sludge plant is a member of the Chloroflexi, but not within the Caldilinea, as reported for this morphotype in Danish plants. Instead, it is a member of the Anaerolineae. The fluorescent signals generated in these filaments using the FISH probes designed here were unevenly distributed, a situation similar to that seen earlier in the Anaerolineae morphotype 0092 to which it is more closely related phylogenetically than it is to the Caldilinea morphotype 0803. FISH-based surveys showed that this 0803 phylotype is uncommon in Australian activated sludge systems, and where seen is present usually at low abundances. The FISH probes described here will facilitate attempts to map the distribution and impact of this Australian filament morphotype 0803 in activated sludge systems of different configurations in plants around the world.

  2. Modelling Cr(VI) removal by a combined carbon-activated sludge system

    Energy Technology Data Exchange (ETDEWEB)

    Orozco, A. Micaela Ferro [Centro de Investigacion y Desarrollo en Criotecnologia de Alimentos (CIDCA), CONICET, Fac. de Cs. Exactas, UNLP. 47 y 116 (B1900AJJ), La Plata (Argentina); Contreras, Edgardo M. [Centro de Investigacion y Desarrollo en Criotecnologia de Alimentos (CIDCA), CONICET, Fac. de Cs. Exactas, UNLP. 47 y 116 (B1900AJJ), La Plata (Argentina)], E-mail: econtrer@quimica.unlp.edu.ar; Zaritzky, Noemi E. [Centro de Investigacion y Desarrollo en Criotecnologia de Alimentos (CIDCA), CONICET, Fac. de Cs. Exactas, UNLP. 47 y 116 (B1900AJJ), La Plata (Argentina); Fac. de Ingenieria, UNLP. 47 y 1 (B1900AJJ), La Plata (Argentina)

    2008-01-15

    The combined carbon-activated sludge process has been proposed as an alternative to protect the biomass against toxic substances in wastewaters; however, the information about the effect of powdered-activated carbon (PAC) addition in activated sludge reactors for the treatment of wastewaters containing Cr(VI) is limited. The objectives of the present study were: (a) to evaluate the removal of hexavalent chromium by (i) activated sludge microorganisms in aerobic batch reactors, (ii) powdered-activated carbon, and (iii) the combined action of powdered-activated carbon and biomass; (b) to propose mathematical models that interpret the experimental results. Different Cr(VI) removal systems were tested: (S1) biomass (activated sludge), (S2) PAC, and (S3) the combined activated carbon-biomass system. A Monod-based mathematical model was used to describe the kinetics of Cr(VI) removal in the system S1. A first-order kinetics with respect to Cr(VI) and PAC respectively, was proposed to model the removal of Cr(VI) in the system S2. Cr(VI) removal in the combined carbon-biomass system (S3) was faster than both Cr(VI) removal using PAC or activated sludge individually. Results showed that the removal of Cr(VI) using the activated carbon-biomass system (S3) was adequately described by combining the kinetic equations proposed for the systems S1 and S2.

  3. Optimum operation conditions of nitrogen and phosphorus removal by a biofilm-activated-sludge system

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    In the biofilm and activated sludge combined system, denitrifying bacteria attached on the fibrous carriers in the anoxic tank, while the sludge containing nitrifying and phosphorus removal bacteria was only recirculated between the aerobic and anaerobic tanks. Therefore, the factors affected and restricted nitrification, denitrification and phosphorus removal in a traditional A/A/O process were resolved. This paper describes the optimum operation conditions for nitrogen and phosphorus removal using this system.

  4. Protists as bioindicators in activated sludge: Identification, ecology and future needs.

    Science.gov (United States)

    Foissner, Wilhelm

    2016-08-01

    When the activated sludge process was developed, operators and scientists soon recognized protists as valuable indicators. However, only when Curds et al. (1968) showed with a few photographs the need of ciliates for a clear plant effluent, sewage protistology began to bloom but was limited by the need of species identification. Still, this is a major problem although several good guides are available. Thus, molecular kits should be developed for identification. Protists are indicators in two stages of wastewater treatment, viz., in the activated sludge and in the environmental water receiving the plant effluent. Continuous control of the protist and bacterial communities can prevent biological sludge foaming and bulking and may greatly save money for sludge oxygenation because several protist species are excellent indicators for the amount of oxygen present. The investigation of the effluent-receiving rivers gives a solid indication about the long term function of sewage works. The literature on protist bioindication in activated sludge is widely distributed. Thus, I compiled the data in a simple Table, showing which communities and species indicate good, mediocre, or poor plant performance. Further, many details on indication are provided, such as sludge loading and nitrifying conditions. Such specific features should be improved by appropriate statistics and more reliable identification of species. Then, protistologists have a fair chance to become important in wastewater works. Activated sludge is a unique habitat for particular species, often poorly or even undescribed. As an example, I present two new species. The first is a minute (∼30μm) Metacystis that makes an up to 300μm-sized mucous envelope mimicking a sludge floc. The second is a Phialina that is unique in having the contractile vacuole slightly posterior to mid-body. Finally, I provide a list of species which have the type locality in sewage plants. Copyright © 2016 Elsevier GmbH. All rights

  5. Key factors governing alkaline pretreatment of waste activated sludge

    Institute of Scientific and Technical Information of China (English)

    Xianli Shi; Li Deng; Fangfang Sun; Jieyu Liang; Xu Deng

    2015-01-01

    Alkaline pretreatment is an effective technology to disintegrate sewage sludge, where alkali dosage and sludge concentration are two important factors. pH value or alkali concentration is usually adjusted in order to deter-mine a proper dosage of alkali. Our work has found that this is not a good strategy. A new parameter, the ratio of alkali to sludge (Ra/s), is more sensitive in controlling the alkali dosage. The sludge concentration Cs and reten-tion time t are two other important factors to consider. The validity of these arguments is confirmed with model-ing and experiments. The individual effect of Ra/s, Cs and t was studied separately. Then the combined effect of these three factors was evaluated. The sludge disintegration degree of 44.7%was achieved with the optimized factors. Furthermore, an alkaline-microwave combined pretreatment process was carried out under these optimized conditions. A high disintegration degree of 62.3%was achieved while the energy consumption of microwave was much lower than previously reported.

  6. Anaerobic co-digestion of waste activated sludge and greasy sludge from flotation process: Batch versus CSTR experiments to investigate optimal design

    OpenAIRE

    Girault, R.; Bridoux, G.; Nauleau, F.; Poullain, C.; Buffet, J.; Peu, P.; Sadowski, A.G.; Béline, F.

    2012-01-01

    In this study, the maximum ratio of greasy sluvdge to incorporate with waste activated sludge was investigated in batch and CSTR experiments. In batch experiments, inhibition occurred with a greasy sludge ratio of more than 20-30% of the feed COD. In CSTR experiments, the optimal greasy sludge ratio was 60% of the feed COD and inhibition occurred above a ratio of 80%. Hence, batch experiments can predict the CSTR yield when the degradation phenomenon are additive but cannot be used to determi...

  7. Innovative strategies for the reduction of sludge production in activated sludge plant: BIOLYSIS O and BIOLYSIS E

    Energy Technology Data Exchange (ETDEWEB)

    Deleris, Stephane; Larose, A.; Geaugey, V.; Lebrunn, Thierry

    2003-07-01

    Management of the excess sludge production resulting from biological wastewater treatment is one of the most important economic and environmental issues for the next decade. New stringent regulations regarding sludge treatment and disposal imposed in several countries as well as social and environmental concerns, have resulted in an increasing interest in processes allowing the reduction of excess sludge production. Following a 5 years research program, Ondeo-Degremont has developed two processes, Biolysis O and Biolysis E, designed to reduce sludge production during biological wastewater treatment. Experiment performed with Biolysis technologies confirmed that high (up to 80%) reduction of excess sludge production can be reached while good treatment performances are maintained, in agreement with regulation standards. Economical data demonstrate the competitiveness of Biolysis processes. Such processes appear to be a valuable alternative to solve the problem of sludge treatment, to protect operators from the evolution of legislation of sludge treatment and from risks inherent to final sludge disposal.

  8. Sludge batch 9 (SB9) acceptance evaluation. Radionuclide concentrations in tank 51 SB9 qualification sample prepared at SRNL

    Energy Technology Data Exchange (ETDEWEB)

    Bannochie, C. J. [Savannah River Site (SRS), Aiken, SC (United States); Diprete, D. P. [Savannah River Site (SRS), Aiken, SC (United States); Pareizs, J. M. [Savannah River Site (SRS), Aiken, SC (United States)

    2016-02-10

    Presented in this report are radionuclide concentrations required as part of the program of qualifying Sludge Batch 9 (SB9) for processing in the Defense Waste Processing Facility (DWPF). The SB9 material is currently in Tank 51 and has been washed and prepared for transfer to Tank 40. The acceptance evaluation needs to be completed prior to the transfer of the material in Tank 51 to Tank 40. The sludge slurry in Tank 40 has already been qualified for DWPF processing and is currently being processed as Sludge Batch 8 (SB8). The radionuclide concentrations were measured or estimated in the Tank 51 SB9 Washed Qualification Sample prepared at Savannah River National Laboratory (SRNL). This sample was prepared from a three liter sample of Tank 51 sludge slurry (HTF-51-15-81) taken on July 23, 2015. The sample was delivered to SRNL where it was initially characterized in the Shielded Cells. Under the direction of Savannah River Remediation (SRR) it was then adjusted per the Tank Farm washing strategy as of October 20, 2015. This final slurry now has a composition expected to be similar to that of the slurry in Tank 51 after final preparations have been made for transfer of that slurry to Tank 40.

  9. Sludge batch 9 (SB9) accepance evaluation: Radionuclide concentrations in tank 51 SB9 qualification sample prepared at SRNL

    Energy Technology Data Exchange (ETDEWEB)

    Bannochie, C. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Diprete, D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Pareizs, J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-03-01

    Presented in this report are radionuclide concentrations required as part of the program of qualifying Sludge Batch 9 (SB9) for processing in the Defense Waste Processing Facility (DWPF). The SB9 material is currently in Tank 51 and has been washed and prepared for transfer to Tank 40. The acceptance evaluation needs to be completed prior to the transfer of the material in Tank 51 to Tank 40. The sludge slurry in Tank 40 has already been qualified for DWPF processing and is currently being processed as Sludge Batch 8 (SB8). The radionuclide concentrations were measured or estimated in the Tank 51 SB9 Washed Qualification Sample prepared at Savannah River National Laboratory (SRNL). This sample was prepared from a three liter sample of Tank 51 sludge slurry (HTF-51-15-81) taken on July 23, 2015. The sample was delivered to SRNL where it was initially characterized in the Shielded Cells. Under the direction of Savannah River Remediation (SRR) it was then adjusted per the Tank Farm washing strategy as of October 20, 2015. This final slurry now has a compositioniv expected to be similar to that of the slurry in Tank 51 after final preparations have been made for transfer of that slurry to Tank 40.

  10. Safety evaluation for packaging for the transport of K Basin sludge samples in the PAS-1 cask

    Energy Technology Data Exchange (ETDEWEB)

    SMITH, R.J.

    1998-11-17

    This safety evaluation for packaging authorizes the shipment of up to two 4-L sludge samples to and from the 325 Lab or 222-S Lab for characterization. The safety of this shipment is based on the current U.S. Department of Energy Certification of Compliance (CoC) for the PAS-1 cask, USA/9184/B(U) (DOE).

  11. Design and simulation of an activated sludge unit associated to a continuous reactor to remove heavy metals

    Energy Technology Data Exchange (ETDEWEB)

    D`Avila, J.S.; Nascimento, R.R. [Ambientec Consultoria Ltda., Aracaju, SE (Brazil)

    1993-12-31

    A software was developed to design and simulate an activated sludge unit associated to a new technology to remove heavy metals from wastewater. In this process, a continuous high efficiency biphasic reactor operates by using particles of activated peat in conjugation with the sludge unit. The results obtained may be useful to increase the efficiency or to reduce the design and operational costs involved in a activated sludge unit. (author). 5 refs., 2 tabs.

  12. Surfactant coupled sonic pretreatment of waste activated sludge for energetically positive biogas generation.

    Science.gov (United States)

    Ushani, U; Rajesh Banu, J; Tamilarasan, K; Kavitha, S; Tae Yeom, Ick

    2017-10-01

    The objective of this study was to evaluate the effect of dioctyl sodium sulphosuccinate (DOSS, a surfactant) on lysis rate of sludge and specific energy required for sonic pretreatment of waste activated sludge (WAS). Different ultrasonic power levels, WAS concentrations, DOSS dosages, and specific energy levels were used to compare pretreatment efficiencies. At an optimum time of 10min with ultrasonic power level of 160W, DOSS coupled sonic pretreatment resulted in better lysis rate (24.7%) of sludge than sonic pretreatment (17.6%). Biodegradability estimation through non-linear regression modeling revealed that DOSS coupled ultrasound pretreatment of sludge showed better biodegradability with higher hydrolysis constant (about 0.25d(-1)) than sonic pretreatment (0.19d(-1)). Nearly six times less energy was required for DOSS coupled ultrasound pretreatment compared to that required for sonic pretreatment. Therefore, DOSS coupled ultrasound pretreatment makes the pretreatment process energetically positive. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Production of biodegradable plastics from activated sludge generated from a food processing industrial wastewater treatment plant.

    Science.gov (United States)

    Suresh Kumar, M; Mudliar, S N; Reddy, K M K; Chakrabarti, T

    2004-12-01

    Most of the excess sludge from a wastewater treatment plant (60%) is disposed by landfill. As a resource utilization of excess sludge, the production of biodegradable plastics using the sludge has been proposed. Storage polymers in bacterial cells can be extracted and used as biodegradable plastics. However, widespread applications have been limited by high production cost. In the present study, activated sludge bacteria in a conventional wastewater treatment system were induced, by controlling the carbon: nitrogen ratio to accumulate storage polymers. Polymer yield increased to a maximum 33% of biomass (w/w) when the C/N ratio was increased from 24 to 144, where as specific growth yield decreased with increasing C/N ratio. The conditions which are required for the maximum polymer accumulation were optimized and are discussed.

  14. Extracellular polymeric substances and dewaterability of waste activated sludge during anaerobic digestion.

    Science.gov (United States)

    Ye, Fenxia; Liu, Xinwen; Li, Ying

    2014-01-01

    Anaerobic digestion of waste activated sludge was conducted to gain insight into the mechanisms underlying change in sludge dewaterability during its anaerobic digestion. Unexpectedly, the results indicated that sludge dewatering properties measured by capillary suction time only deteriorated after 10 days of anaerobic digestion, after which dewaterability recovered and remained stable. The loosely bound extracellular polymeric substance (LB-EPS) content increased three-fold after 20 days of anaerobic digestion, and did not change significantly during the remaining 30 days. The tightly bound EPS (TB-EPS) content reduced slightly after 20 days of anaerobic digestion, and stabilized during the last 30 days. Polysaccharides (PS) and proteins (PN) content in LB-EPS increased after 10 days of anaerobic digestion. However, PS and PN contents in TB-EPS decreased slightly. The relationship analysis showed that only LB-EPS correlated with dewaterability of the sludge during anaerobic digestion.

  15. Rapid determination of lead and cadmium in sewage sludge samples using electrothermal atomic absorption spectrometry with slurry sample introduction

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-Garcia, I.; Vinas, P.; Arroyo-Cortez, J.; Hernandez-Cordoba, M. [Dept. of Analytical Chem., Univ. of Murcia (Spain)

    2000-08-01

    Lead and cadmium concentrations in sewage sludge samples are determined by suspending the ground samples in a solution containing 10% (v/v) concentrated hydrofluoric acid, 1% (v/v) concentrated nitric acid, 0.5% (m/v) dihydrogen ammonium phosphate and 0.1% (m/v) sodium hexametaphosphate. Aliquots of 20 {mu}L of these suspensions (4 mg/mL) are diluted to 1000 {mu}L with the same solution and then injected into the electrothermal atomizer. The drying stage is performed by programming a 400 C temperature, a ramp time of 20 s and a hold time of 15 s on the power supply of the atomizer. No ashing step is used. Platform atomization is carried out at 1600 and 1800 C for Pb and Cd, respectively. Calibration is performed using aqueous standards in the 5-75 and 0.2- 5 {mu}g/L Pb and Cd ranges, respectively. Results obtained for three certified reference materials and four samples demonstrate the reliability of the procedures described. (orig.)

  16. [Research on the treatment of wastewater containing PVA by ozonation-activated sludge process].

    Science.gov (United States)

    Xing, Xiao-Qiong; Huang, Cheng-Lan; Liu, Min; Chen, Ying

    2012-11-01

    The wastewater containing polyvinyl alcohol (PVA) was characterized with poor biodegradability, and was difficult to remove. In order to find an economically reasonable and practical technology, the research on the removal efficiency of different concentration wastewater containing PVA by ozonation-activated sludge process was studied, and the result was compared with the traditional activated sludge process. The results showed that the ozonation-activated sludge process was not suitable for treating influent with COD below 500 mg x L(-1) and the wastewater PVA concentration was 10-30 mg x L(-1). When the influent COD was between 500-800 mg x L(-1) and the PVA concentration was 15-60 mg x L(-1), the system had advantages on dealing with this kind of wastewater, and the average removal efficiency of COD and PVA were 92.8% and 57.4%, which were better than the traditional activated sludge process 4.1% and 15.2% respectively. In addition, the effluent concentrations of COD could keep between 30-60 mg x L(-1). When the influent COD was 1 000-1 200 mg x L(-1) and the PVA concentration was 20-70 mg x L(-1), the average removal efficiencies of COD and PVA were 90.9% and 45.3%, which were better than the traditional activated sludge process 12.8% and 12.1% respectively, but the effluent should to be further treated. Compared with the traditional activated sludge process, ozonation-activated sludge process had high treatment efficiency, stable running effect, and effectively in dealing with industrial wastewater containing PVA.

  17. Hybrid alkali-hydrodynamic disintegration of waste-activated sludge before two-stage anaerobic digestion process.

    Science.gov (United States)

    Grübel, Klaudiusz; Suschka, Jan

    2015-05-01

    The first step of anaerobic digestion, the hydrolysis, is regarded as the rate-limiting step in the degradation of complex organic compounds, such as waste-activated sludge (WAS). The aim of lab-scale experiments was to pre-hydrolyze the sludge by means of low intensive alkaline sludge conditioning before applying hydrodynamic disintegration, as the pre-treatment procedure. Application of both processes as a hybrid disintegration sludge technology resulted in a higher organic matter release (soluble chemical oxygen demand (SCOD)) to the liquid sludge phase compared with the effects of processes conducted separately. The total SCOD after alkalization at 9 pH (pH in the range of 8.96-9.10, SCOD = 600 mg O2/L) and after hydrodynamic (SCOD = 1450 mg O2/L) disintegration equaled to 2050 mg/L. However, due to the synergistic effect, the obtained SCOD value amounted to 2800 mg/L, which constitutes an additional chemical oxygen demand (COD) dissolution of about 35 %. Similarly, the synergistic effect after alkalization at 10 pH was also obtained. The applied hybrid pre-hydrolysis technology resulted in a disintegration degree of 28-35%. The experiments aimed at selection of the most appropriate procedures in terms of optimal sludge digestion results, including high organic matter degradation (removal) and high biogas production. The analyzed soft hybrid technology influenced the effectiveness of mesophilic/thermophilic anaerobic digestion in a positive way and ensured the sludge minimization. The adopted pre-treatment technology (alkalization + hydrodynamic cavitation) resulted in 22-27% higher biogas production and 13-28% higher biogas yield. After two stages of anaerobic digestion (mesophilic conditions (MAD) + thermophilic anaerobic digestion (TAD)), the highest total solids (TS) reduction amounted to 45.6% and was received for the following sample at 7 days MAD + 17 days TAD. About 7% higher TS reduction was noticed compared with the sample after 9

  18. Application of a novel functional gene microarray to probe the functional ecology of ammonia oxidation in nitrifying activated sludge.

    Directory of Open Access Journals (Sweden)

    Michael D Short

    Full Text Available We report on the first study trialling a newly-developed, functional gene microarray (FGA for characterising bacterial and archaeal ammonia oxidisers in activated sludge. Mixed liquor (ML and media biofilm samples from a full-scale integrated fixed-film activated sludge (IFAS plant were analysed with the FGA to profile the diversity and relative abundance of ammonia-oxidising archaea and bacteria (AOA and AOB respectively. FGA analyses of AOA and AOB communities revealed ubiquitous distribution of AOA across all samples - an important finding for these newly-discovered and poorly characterised organisms. Results also revealed striking differences in the functional ecology of attached versus suspended communities within the IFAS reactor. Quantitative assessment of AOB and AOA functional gene abundance revealed a dominance of AOB in the ML and approximately equal distribution of AOA and AOB in the media-attached biofilm. Subsequent correlations of functional gene abundance data with key water quality parameters suggested an important functional role for media-attached AOB in particular for IFAS reactor nitrification performance and indicate possible functional redundancy in some IFAS ammonia oxidiser communities. Results from this investigation demonstrate the capacity of the FGA to resolve subtle ecological shifts in key microbial communities in nitrifying activated sludge and indicate its value as a tool for better understanding the linkages between the ecology and performance of these engineered systems.

  19. Cost estimation and economical evaluation of three configurations of activated sludge process for a wastewater treatment plant (WWTP) using simulation

    National Research Council Canada - National Science Library

    Jafarinejad, Shahryar

    ...s. Economical modeling and cost estimation of activated sludge processes are crucial for designing, construction, and forecasting future economical requirements of wastewater treatment plants (WWTPs...

  20. Chronic Response of Waste Activated Sludge Fermentation to Titanium Dioxide Nanoparticles☆

    Institute of Scientific and Technical Information of China (English)

    Yinguang Chen; Hui Mu; Xiong Zheng⁎

    2014-01-01

    Due to the large-scale production and wide applications, many nanoparticles (NPs) enter wastewater treatment plants and accumulate in activated sludge. It is reported that titanium dioxide (TiO2) NPs show severe damage to many model microbes. However, it is stil unknown whether the long-term (e.g., 100 d) presence of TiO2 NPs would affect the performance of sludge fermentation. In this study, long-term exposure experiments (105 d) were conducted to investigate the potential risk of TiO2 NPs to sludge fermentation system. It is found that the presence of environmental y relevant [6 mg·(g TSS)−1] and higher [150 mg·(g TSS)−1] concentrations of TiO2 NPs does not affect methane production from sludge fermentation. The analysis of fluorescence in situ hybridiza-tion indicates that these concentrations of TiO2 NPs present marginal influences on abundances of bacteria and methanogenic archaea in sludge fermentation system. The viability of sludge microorganisms and activities of key enzymes related to methane production such as protease, acetate kinase, and coenzyme F420 are unchanged by the long-term presence of 6 and 150 mg·(g TSS)−1 of TiO2 NPs. Further investigations reveal that the insolu-bility of NPs and the protection role of sludge extracellular polymeric substances are the main reasons for the marginal influence of TiO2 NPs on sludge fermentation.

  1. Roseomonas eburnea sp. nov., isolated from activated sludge.

    Science.gov (United States)

    Wang, Chenghong; Deng, Shikai; Liu, Xin; Yao, Li; Shi, Chao; Jiang, Jin; Kwon, Soon-Wo; He, Jian; Li, Jiayou

    2016-01-01

    A Gram-stain-negative, aerobic, short rod-shaped, non-endospore-forming, ivory-pigmented and non-motile bacterium, designated strain BUT-5T, was isolated from activated sludge of an herbicides-manufacturing wastewater treatment facility in Jiangsu Province, China. The major fatty acids (>5 % of total fatty acids) were C16 : 0, C18 : 1 2-OH and summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c). The predominant respiratory quinone was ubiquinone Q-10. The polar lipids profile of strain BUT-5T included diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine and two unknown aminolipids. The DNA G+C content was 67.6 mol%. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain BUT-5T showed the highest sequence similarities to Roseomonas soli 5N26T (97.5 % 16S rRNA gene sequence similarity), followed by Roseomonas lacus TH-G33T (97.3 %) and Roseomonas terrae DS-48T (97.1 %). Strain BUT-5T showed low DNA-DNA relatedness with Roseomonas soli KACC 16376T (41 %), Roseomonas lacus KACC 11678T (46 %) and Roseomonas terrae KACC 12677T (42 %), respectively. On the basis of phenotypic and genotypic properties, as well as chemotaxonomic data, strain BUT-5T represents a novel species of the genus Roseomonas, for which the name Roseomonas eburnea sp. nov. is proposed. The type strain is BUT-5T ( = CCTCC AB2013276T = KACC 17166T).

  2. Study on factors of affecting sedimentation performance of activated sludge in A-step of AB process

    Institute of Scientific and Technical Information of China (English)

    ZHOUJian; TIANWenlong; LONGTengrui

    2003-01-01

    The factors including inflow SS, pythogenous sewage, loading rate Ns, dissolved oxygen which affect sedimentation performance of A-step activated sludge were studied in the paper. The experimental results indicated: the inflow SS distinctly improve sedimentation performance of activated sludge; the pythogenous sewage easily worsen sedimentation performance of activated sludge, and canceling primary sedimentation tank and cesspool would avail to stable running of sewage treatment plant. The effect of loading rate Ns on EPS is highly remarkable, and EPS and polysaccharide are correlated evidently with sedimentation performance of activated sludge. When high loading rate Ns is 3.0 kgBOD5/kgMLSS·d, EPS is 17.15mgEPS/gVSS and polysaccharide is 8.15mg/g VSS, which is less 40% than activated sludge of 0.3 kgBOD5/kgMLSS·d loading rate Ns; meanwhile the effect of dissolved oxygen on EPS is less, and dissolved oxygen does not affect sedimentation performance of activated sludge in high loading rate; the polysaccharide content of activated sludge in high loading rate does not benefit the growth of filament, and furthermore the hydrophobicity of activated sludge is good, which cause good sedimentation performance of sludge in high loading rate.

  3. Influence of different anoxic time exposures on active biomass, protozoa and filamentous bacteria in activated sludge.

    Science.gov (United States)

    Rodriguez-Perez, S; Fermoso, F G; Arnaiz, C

    Medium-sized wastewater treatment plants are considered too small to implement anaerobic digestion technologies and too large for extensive treatments. A promising option as a sewage sludge reduction method is the inclusion of anoxic time exposures. In the present study, three different anoxic time exposures of 12, 6 and 4 hours have been studied to reduce sewage sludge production. The best anoxic time exposure was observed under anoxic/oxic cycles of 6 hours, which reduced 29.63% of the biomass production compared with the oxic control conditions. The sludge under different anoxic time exposures, even with a lower active biomass concentration than the oxic control conditions, showed a much higher metabolic activity than the oxic control conditions. Microbiological results suggested that both protozoa density and abundance of filamentous bacteria decrease under anoxic time exposures compared to oxic control conditions. The anoxic time exposures 6/6 showed the highest reduction in both protozoa density, 37.5%, and abundance of filamentous bacteria, 41.1%, in comparison to the oxic control conditions. The groups of crawling ciliates, carnivorous ciliates and filamentous bacteria were highly influenced by the anoxic time exposures. Protozoa density and abundance of filamentous bacteria have been shown as promising bioindicators of biomass production reduction.

  4. ACTIVE PEC APPLICATIONS, THE PEC WEBSITE, AND SLUDGE STABILITY RESEARCH

    Science.gov (United States)

    Since it's creation in 1985, the Pathogen Equivalency Committee (PEC) has been reviewing novel sludge disinfection technologies with regards to their abilities to protect human health and the environment. The PEC is charged to make recommendations on whether these novel technolog...

  5. Molecular characterization of activated sludge from a seawater‐processing wastewater treatment plant

    Science.gov (United States)

    Sánchez, Olga; Garrido, Laura; Forn, Irene; Massana, Ramon; Maldonado, Manuel Ignacio; Mas, Jordi

    2011-01-01

    Summary The prokaryotic community composition of activated sludge from a seawater‐processing wastewater treatment plant (Almeria, Spain) was investigated by using the rRNA approach, combining different molecular techniques such as denaturing gradient gel electrophoresis (DGGE), clone libraries and in situ hybridization (FISH and CARD‐FISH). Most of the sequences retrieved in the DGGE and the clone libraries were similar to uncultured members of different phyla. The most abundant sequence recovered from Bacteria in the clone library corresponded to a bacterium from the Deinococcus–Thermus cluster (almost 77% of the clones), and the library included members from other groups such as the Alpha, Gamma and Delta subclasses of Proteobacteria, the Bacteroidetes and Firmicutes. Concerning the archaeal clone library, we basically found sequences related to different orders of methanogenic Archaea, in correspondence with the recovered DGGE bands. Enumeration of DAPI (4′,6‐diamidino‐2‐phenylindole) stained cells from two different activated sludge samples after a mechanical flocculation disruption revealed a mean cell count of 1.6 × 109 ml−1. Around 94% of DAPI counts (mean value from both samples) hybridized with a Bacteria specific probe. Alphaproteobacteria were the dominant bacterial group (36% of DAPI counts), while Beta‐, Delta‐ and Gammaproteobacteria, Bacteroidetes, Actinobacteria and Firmicutes contributed to lower proportions (between 0.5–5.7% of DAPI counts). Archaea accounted only for 6% of DAPI counts. In addition, specific primers for amplification of the amoA (ammonia monooxygenase) gene were used to detect the presence of Beta, Gamma and archaeal nitrifiers, yielding positive amplifications only for Betaproteobacteria. This, together with negative in situ hybridizations with probes for well‐known nitrifiying bacteria, suggests that nitrification is performed by still undetected microorganisms. In summary, the combination of the

  6. 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...

  7. 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

    2015-01-01

    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...

  8. A comparative adsorption study: 17β-estradiol onto aerobic granular sludge and activated sludge.

    Science.gov (United States)

    Zheng, Xiao-ying; He, Yu-jie; Chen, Wei; Wang, Ming-yang; Cao, Su-lan; Ni, Ming; Chen, Yu

    2016-01-01

    Adsorption plays a significant role in removing hydrophobic 17β-estradiol (E2) from wastewater. Batch experiments were conducted to compare the adsorption of E2 onto activated aerobic granular sludge (AGS) and activated sludge (AS), and features evaluated included the adsorption kinetics, thermodynamics, and influence of other environmental factors. By using a non-chemical wet-heat technique, both AGS and AS were treated to inactivated status. Then, after loading E2, the adsorption equilibrium capacity of the AGS was found to be greater than that of the AS at the same initial concentration of E2. Moreover, both the adsorption processes corresponded to a pseudo-second-order kinetic model; the adsorption rate constant of AGS was found to be higher and the half-adsorption time was shorter than that of AS. Next, evaluations of adsorption isotherms and thermodynamics indicated that the adsorption process was mainly a physical process. Lower temperatures facilitated a higher equilibrium adsorption capacity. However, the adsorption binding sites of AGS were distributed more uniformly at higher temperature, in contrast to the distribution found for AS. Finally, acidic conditions and an appropriate ionic strength (0.4 mol/L) were found to be particularly conducive to the adsorption process. Overall, the results showed that AGS has the potential to adsorb E2 with significant efficiency, thereby offering a new and more efficient means of treating E2 and trace oestrogens in wastewater.

  9. An activated sludge model for xenobiotic organic micro-pollutants (ASM-X)

    DEFF Research Database (Denmark)

    Plósz, Benedek; Lehnberg, K.; Dott, W.

    2010-01-01

    deteriorate; thereby hindering the effluent quality of secondary treatment step, and thereby increasing the XOM mass load on the tertiary treatment step. Besides the impact of different redox conditions, divalent iron-salt dosing used for enhanced phosphorus removal and pH have been identified as potential...... the XOMs content of pre-clarified municipal sewage. Evaluation of the model structure is carried out in dynamic simulations using data obtained in samples taken in a measuring campaign in a full-scale activated sludge wastewater treatment plant (WWTP). Our results suggest that the sorption....... We additionally show that the impact of Fe-salt added can vary under aerobic, anoxic and anaerobic conditions, and that the presence of nitrate can significantly influence CIP partitioning under aerobic conditions. The possible depletion of nitrate in the pre-anoxic effluent can additionally...

  10. Environmental biodegradation of haloarchaea-produced poly(3-hydroxybutyrate-co-3-hydroxyvalerate) in activated sludge

    DEFF Research Database (Denmark)

    Liu, Xiao-Bin; Wu, Linping; Hou, Jing

    2016-01-01

    Novel poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBHV) copolymers produced by haloarchaea are excellent candidate biomaterials. However, there is no report hitherto focusing on the biodegradation of PHBHV synthesized by haloarchaea. In this study, an environmental biodegradation of haloarchaea......-order copolymer PHBHV-1 (O-PHBHV-1) possessing the highest surface roughness. The order of biodegradation rate was in the opposite trend to the degree of crystallizability of the films. Meanwhile, thermal degradation temperature of most films decreased after biodegradation. Additionally, the surface erosion...... of films was confirmed by scanning electron microscopy. The dominant bacteria probably responsible for the degradation process were identified in the activated sludge. It was inferred that the degradation rate of haloarchaea-produced PHBHV films mainly depended on sample crystallinity, which was determined...

  11. Effect of acetic acid on lipid accumulation by glucose-fed activated sludge cultures

    Energy Technology Data Exchange (ETDEWEB)

    Mondala, Andro; Hernandez, Rafael; French, Todd; McFarland, Linda; Sparks, Darrell; Holmes, William; Haque, Monica

    2012-01-01

    The effect of acetic acid, a lignocellulose hydrolysis by-product, on lipid accumulation by activated sludge cultures grown on glucose was investigated. This was done to assess the possible application of lignocellulose as low-cost and renewable fermentation substrates for biofuel feedstock production. Results: Biomass yield was reduced by around 54% at a 2 g L -1 acetic acid dosage but was increased by around 18% at 10 g L -1 acetic acid dosage relative to the control run. The final gravimetric lipid contents at 2 and 10 g L -1 acetic acid levels were 12.5 + 0.7% and 8.8 + 3.2% w/w, respectively, which were lower than the control (17.8 + 2.8% w/w). However, biodiesel yields from activated sludge grown with acetic acid (5.6 + 0.6% w/w for 2 g L -1 acetic acid and 4.2 + 3.0% w/w for 10 g L -1 acetic acid) were higher than in raw activated sludge (1-2% w/w). The fatty acid profiles of the accumulated lipids were similar with conventional plant oil biodiesel feedstocks. Conclusions: Acetic acid enhanced biomass production by activated sludge at high levels but reduced lipid production. Further studies are needed to enhance acetic acid utilization by activated sludge microorganisms for lipid biosynthesis.

  12. MiDAS: the field guide to the microbes of activated sludge.

    Science.gov (United States)

    McIlroy, Simon Jon; Saunders, Aaron Marc; Albertsen, Mads; Nierychlo, Marta; McIlroy, Bianca; Hansen, Aviaja Anna; Karst, Søren Michael; Nielsen, Jeppe Lund; Nielsen, Per Halkjær

    2015-01-01

    The Microbial Database for Activated Sludge (MiDAS) field guide is a freely available online resource linking the identity of abundant and process critical microorganisms in activated sludge wastewater treatment systems to available data related to their functional importance. Phenotypic properties of some of these genera are described, but most are known only from sequence data. The MiDAS taxonomy is a manual curation of the SILVA taxonomy that proposes a name for all genus-level taxa observed to be abundant by large-scale 16 S rRNA gene amplicon sequencing of full-scale activated sludge communities. The taxonomy can be used to classify unknown sequences, and the online MiDAS field guide links the identity to the available information about their morphology, diversity, physiology and distribution. The use of a common taxonomy across the field will provide a solid foundation for the study of microbial ecology of the activated sludge process and related treatment processes. The online MiDAS field guide is a collaborative workspace intended to facilitate a better understanding of the ecology of activated sludge and related treatment processes--knowledge that will be an invaluable resource for the optimal design and operation of these systems. © The Author(s) 2015. Published by Oxford University Press.

  13. Study of kinetics of degradation of cyclohexane carboxylic acid by acclimated activated sludge.

    Science.gov (United States)

    Wang, Chunhua; Shi, Shuian; Chen, Hongyan

    2016-01-01

    Activated sludge contains complex microorganisms, which are highly effective biodegrading agents. In this study, the kinetics of biodegradation of cyclohexane carboxylic acid (CHCA) by an acclimated aerobic activated sludge were investigated. The results showed that after 180 days of acclimation, the activated sludge could steadily degrade >90% of the CHCA in 120 h. The degradation of CHCA by the acclimated activated sludge could be modeled using a first-order kinetics equation. The equations for the degradation kinetics for different initial CHCA concentrations were also obtained. The kinetics constant, kd, decreased with an increase in the CHCA concentration, indicating that, at high concentrations, CHCA had an inhibiting effect on the microorganisms in the activated sludge. The effects of pH on the degradation kinetics of CHCA were also investigated. The results showed that a pH of 10 afforded the highest degradation rate, indicating that basic conditions significantly promoted the degradation of CHCA. Moreover, it was found that the degradation efficiency for CHCA increased with an increase in temperature and concentration of dissolved oxygen under the experimental conditions.

  14. Evaluation of activated sludge for biodegradation of propylene glycol as an aircraft deicing fluid.

    Science.gov (United States)

    Delorit, Justin D; Racz, LeeAnn

    2014-04-01

    Aircraft deicing fluid used at airport facilities is often collected for treatment or disposal in order to prevent serious ecological threats to nearby surface waters. This study investigated lab scale degradation of propylene glycol, the active ingredient in a common aircraft deicing fluid, by way of a laboratory-scale sequencing batch reactor containing municipal waste water treatment facility activated sludge performing simultaneous organic carbon oxidation and nitrification. The ability of activated sludge to remove propylene glycol was evaluated by studying the biodegradation and sorption characteristics of propylene glycol in an activated sludge medium. The results indicate sorption may play a role in the fate of propylene glycol in AS, and the heterotrophic bacteria readily degrade this compound. Therefore, a field deployable bioreactor may be appropriate for use in flight line applications.

  15. Enhanced waste activated sludge digestion using a submerged anaerobic dynamic membrane bioreactor: performance, sludge characteristics and microbial community

    Science.gov (United States)

    Yu, Hongguang; Wang, Zhiwei; Wu, Zhichao; Zhu, Chaowei

    2016-02-01

    Anaerobic digestion (AD) plays an important role in waste activated sludge (WAS) treatment; however, conventional AD (CAD) process needs substantial improvements, especially for the treatment of WAS with low solids content and poor anaerobic biodegradability. Herein, we propose a submerged anaerobic dynamic membrane bioreactor (AnDMBR) for simultaneous WAS thickening and digestion without any pretreatment. During the long-term operation, the AnDMBR exhibited an enhanced sludge reduction and improved methane production over CAD process. Moreover, the biogas generated in the AnDMBR contained higher methane content than CAD process. Stable carbon isotopic signatures elucidated the occurrence of combined methanogenic pathways in the AnDMBR process, in which hydrogenotrophic methanogenic pathway made a larger contribution to the total methane production. It was also found that organic matter degradation was enhanced in the AnDMBR, thus providing more favorable substrates for microorganisms. Pyrosequencing revealed that Proteobacteria and Bacteroidetes were abundant in bacterial communities and Methanosarcina and Methanosaeta in archaeal communities, which played an important role in the AnDMBR system. This study shed light on the enhanced digestion of WAS using AnDMBR technology.

  16. Steady-state analysis of activated sludge processes with a settler model including sludge compression.

    Science.gov (United States)

    Diehl, S; Zambrano, J; Carlsson, B

    2016-01-01

    A reduced model of a completely stirred-tank bioreactor coupled to a settling tank with recycle is analyzed in its steady states. In the reactor, the concentrations of one dominant particulate biomass and one soluble substrate component are modelled. While the biomass decay rate is assumed to be constant, growth kinetics can depend on both substrate and biomass concentrations, and optionally model substrate inhibition. Compressive and hindered settling phenomena are included using the Bürger-Diehl settler model, which consists of a partial differential equation. Steady-state solutions of this partial differential equation are obtained from an ordinary differential equation, making steady-state analysis of the entire plant difficult. A key result showing that the ordinary differential equation can be replaced with an approximate algebraic equation simplifies model analysis. This algebraic equation takes the location of the sludge-blanket during normal operation into account, allowing for the limiting flux capacity caused by compressive settling to easily be included in the steady-state mass balance equations for the entire plant system. This novel approach grants the possibility of more realistic solutions than other previously published reduced models, comprised of yet simpler settler assumptions. The steady-state concentrations, solids residence time, and the wastage flow ratio are functions of the recycle ratio. Solutions are shown for various growth kinetics; with different values of biomass decay rate, influent volumetric flow, and substrate concentration.

  17. Group-specific small-subunit rRNA hybridization probes to characterize filamentous foaming in activated sludge systems.

    Science.gov (United States)

    de los Reyes, F L; Ritter, W; Raskin, L

    1997-03-01

    Foaming in activated sludge systems is characterized by the formation of a thick, chocolate brown-colored scum that floats on the surface of aeration basins and secondary clarifiers. These viscous foams have been associated with the presence of filamentous mycolic acid-containing actinomycetes. To aid in evaluating the microbial representation in foam, we developed and characterized group-, genus-, and species-specific oligonucleotide probes targeting the small subunit rRNA of the Mycobacterium complex, Gordona spp., and Gordona (Nocardia) amarae, respectively. The use of a universal base analog, 5-nitroindole, in oligonucleotide probe design was evaluated by comparing the characteristics of two different versions of the Mycobacterium complex probe. The temperature of dissociation of each probe was determined. Probe specificity studies with a diverse collection of 67 target and nontarget rRNAs demonstrated the specificity of the probes to the target groups. Whole-cell hybridizations with fluorescein- and rhodamine-labeled probes were performed with pure cultures of various members of the Mycobacterium complex as well as with environmental samples from a full-scale activated sludge plant which experienced foaming. Quantitative membrane hybridizations with activated sludge and anaerobic digester foam showed that 15.0 to 18.3% of the total small-subunit rRNAs could be attributed to members of the Mycobacterium complex, of which a vast majority consisted of Gordona rRNA. Several G. amarae strains made up only a very small percentage of the Gordona strains present. We demonstrated that group-specific rRNA probes are useful tools for the in situ monitoring and identification of filamentous bacteria in activated sludge systems.

  18. Biodegradation of triclosan and formation of methyl-triclosan in activated sludge under aerobic conditions

    DEFF Research Database (Denmark)

    Chen, Xijuan; Nielsen, Jeppe Lund; Furgal, Karolina

    2011-01-01

    Triclosan is an antimicrobial agent which is widely used in household and personal care products. Widespread use of this compound has led to the elevated concentrations of triclosan in wastewater, wastewater treatment plants (WWTPs) and receiving waters. Removal of triclosan and formation...... of triclosan- methyl was investigated in activated sludge from a standard activated sludge WWTP equipped with enhanced biological phosphorus removal. The removal was found to occur mainly under aerobic conditions while under anoxic (nitrate reducing) and anaerobic conditions rather low removal rates were...... determined. In a laboratory-scale activated sludge reactor 75% of the triclosan was removed under aerobic conditions within 150 h, while no removal was observed under anaerobic or anoxic conditions. One percent of the triclosan was converted to triclosan-methyl under aerobic conditions, less under anoxic...

  19. Effect of magnetic nanoparticles on the performance of activated sludge treatment system.

    Science.gov (United States)

    Ni, Shou-Qing; Ni, Jianyuan; Yang, Ning; Wang, Juan

    2013-09-01

    Both short-term and long-term exposure experiments were carried out to investigate the influence of magnetic nanoparticles (NPs) on activated sludge. The short-term presence of 50-200 mg/L of NPs decreased total nitrogen (TN) removal efficiencies, resulted from the acute toxicity of a shock load of NPs. However, long-term exposure of 50 mg/L magnetic NPs were observed to significantly improve TN removal efficiency, partially due to the self-repair function of activated sludge and magnetic-induced bio-effect. Sludge properties and extracellular polymer substrates secretion were affected. Additional investigations with enzyme and FISH assays indicated that short-term exposure of 50 mg/L magnetic NPs led to the abatement of nitrifying bacteria. However, the activities of the enzyme nitrite oxidoreductase and key denitrifying enzymes were increased after long-term exposure.

  20. Challenges encountered when expanding activated sludge models: a case study based on N2O production

    DEFF Research Database (Denmark)

    Snip, Laura; Boiocchi, Riccardo; Flores Alsina, Xavier;

    2014-01-01

    It is common practice in wastewater engineering to extend standard activated sludge models (ASMs) with extra process equations derived from batch experiments. However, such experiments have often been performed under conditions different from the ones normally found in wastewater treatment plants......-scale activated sludge plant. Finally, the simulation results show large differences in oxygen uptake rates, nitritation rates and consequently the quantity of N2O emission (G(N2O)) using the different models......It is common practice in wastewater engineering to extend standard activated sludge models (ASMs) with extra process equations derived from batch experiments. However, such experiments have often been performed under conditions different from the ones normally found in wastewater treatment plants...

  1. Modelling of the Secondary Clarifier Combined with the Activated Sludge Model no. 1

    DEFF Research Database (Denmark)

    Dupont, René; Henze, Mogens

    1992-01-01

    settling, which can be used in combination with the Activated Sludge Model to form a dynamic computer model/program for a wastewater treatment plant. In addition to the flux model, the developed model includes a simple model for predicting the contents of particulate components in the effluent. This latter......Modelling of activated sludge wastewater treatment plants is today generally based on the Activated Sludge Model No. 1 combined with a very simple model for the secondary settler. This paper describes the development of a model for the secondary clarifier based on the general flux theory for zone...... model is a purely empirical model, which connects the effluent quality with the hydraulic load, suspended solids load and the nitrate load. The paper describes the model and gives some basic examples on computer simulations and verification of the model....

  2. Characteristics of PAHs adsorption on inorganic particles and activated sludge in domestic wastewater treatment.

    Science.gov (United States)

    Liu, J J; Wang, X C; Fan, B

    2011-05-01

    The occurrence of polycyclic aromatic hydrocarbons (PAHs) in a domestic wastewater treatment plant (WWTP) was investigated in a 1 year period. In order to understand how PAHs were removed at different stages of the treatment process, adsorption experiments were conducted using quartz sand, kaolinite, and natural clay as inorganic adsorbents and activated sludge as organic adsorbent for adsorbing naphthalene, phenanthrene, and pyrene. As a result, the adsorption of PAHs by the inorganic adsorbents well followed the Langmuir isotherm while that by the activated sludge well followed the Freundlich isotherm. By bridging equilibrium partitioning coefficient with the parameters of adsorption isotherm, a set of mathematical models were developed. Under an assumption that in the primary settler PAHs removal was by adsorption onto inorganic particles and in the biological treatment unit it was by adsorption onto activated sludge, the model calculation results fairly reflected the practical condition in the WWTP.

  3. IASON - Intelligent Activated Sludge Operated by Nanotechnology - Hydrogel Microcarriers in Wastewater Treatment

    Science.gov (United States)

    Fleit, E.; Melicz, Z.; Sándor, D.; Zrínyi, M.; Filipcsei, G.; László, K.; Dékány, I.; Király, Z.

    Performance of biological wastewater treatment depends to a large extent on mechanical strength, size distribution, permeability and other textural properties of the activated sludge flocs. A novel approach was developed in applying synthetic polymer materials to organize floc architecture instead of spontaneously formed activated sludge floc. Developed microcarrier polymer materials were used in our experiments to mitigate technological goals. Preliminary results suggest that the PVA-PAA (polyvinyl alcohol-polyacrylic acid copolymer) is a feasible choice for skeleton material replacing "traditional" activated sludge floc. Use of PVA-PAA hydrogel material as microreactors and methods for biofilm formation of wastewater bacteria on the carrier material are described. Laboratory scale experimental results with microscopic size bioreactors and their potential application for simultaneous nitrification and denitrification are presented.

  4. How adaptation and mass transfer control the biodegradation of linear alkylbenzene sulfonate by activated sludge.

    Science.gov (United States)

    Rittmann, B E; Tularak, P; Lee, K C; Federle, T W; Itrich, N R; Kaiser, S K; Shi, J; McAvoy, D C

    2001-01-01

    We use a nonsteady-state model to evaluate the effects of community adaptation and sorption kinetics on the fate of linear alkylbenzene sulfonate (LAS) in batch experiments conducted with activated sludge that was continuously fed different concentrations of LAS. We observed a sharp decrease in the biodegradation rate between 30 and 60 minutes and the presence of an LAS residual at the end of the batch experiments. The modeling analysis indicates that these phenomena were caused by relatively slow inter-phase mass transport of LAS. The modeling analyses also showed that the amount of LAS-degrading biomass increased when the continuous activated sludge was fed a higher LAS concentration. Although community adaptation to LAS involved accumulation of more LAS degraders, the increase was not proportional to the feed concentration of LAS, which supports the concept that LAS degraders also utilized portions of the general biochemical oxygen demand (BOD) fed to the continuous activated sludge systems.

  5. New insights into co-digestion of activated sludge and food waste: Biogas versus biofertilizer.

    Science.gov (United States)

    Ma, Yingqun; Yin, Yao; Liu, Yu

    2017-10-01

    This study explored two holistic approaches for co-digestion of activated sludge and food waste. In Approach 1, mixed activated sludge and food waste were first hydrolyzed with fungal mash, and produced hydrolysate without separation was directly subject to anaerobic digestion. In Approach 2, solid generated after hydrolysis of food waste by fungal mash was directly converted to biofertilizer, while separated liquid with high soluble COD concentration was further co-digested with activated sludge for biomethane production. Although the potential energy produced from Approach 1 was about 1.8-time higher than that from Approach 2, the total economic revenue generated from Approach 2 was about 1.9-fold of that from Approach 1 due to high market value of biofertilizer. It is expected that this study may lead to a paradigm shift in biosolid management towards environmental and economic sustainability. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. APPLICATION OF RESPIROMETRIC TESTS FOR ASSESSMENT OF METHANOGENIC BACTERIA ACTIVITY IN WASTEWATER SLUDGE PROCESSING

    Directory of Open Access Journals (Sweden)

    Małgorzata Cimochowicz-Rybicka

    2013-07-01

    Full Text Available Production of a methane-rich gas (‘biogas’ is contemporary popular sludges processing technology which allows to generate thermal and/or electric energy. Formal requirements issued by the European Union to promote so called renewable energy resources made these process more attractive leading to its application in WWTPs which were designed based on different sludge handling processes. Authors (as active design engineers noted that dimensioning sludge digestion chamber is usually based on SRT assessment without any emphasis on sludge characteristics. Bio-mass characteristics and the estimation of its activity with respect to methane production are of great importance, from both scientific and practical points of view, as anaerobic digestion appears to be one of crucial processes in municipal wastewater handling and disposal. The authors propose respirometric tests to estimate a biomass potential to produce ‘a biogas’ and several years’ laboratory and full scale experience proved its usefulness and reliability both as a measurement and a design tool applicable in sludge handling. Dimensioning method proposed by authors, allows to construct and optimize operation of digestion chambers based on a methanogenic activity.

  7. Effect of activated sludge properties and membrane operation conditions on fouling characteristics in membrane bioreactors.

    Science.gov (United States)

    Choi, Hyeok; Zhang, Kai; Dionysiou, Dionysios D; Oerther, Daniel B; Sorial, George A

    2006-06-01

    Biofouling control is considered to be a major challenge in operating membrane bioreactors (MBRs) for the treatment of wastewater. This study examined the impact of biological, chemical, and physical properties of activated sludge on membrane filtration performance in laboratory-scale MBRs. Sludges with different microbial communities were produced using pseudo-continuous stirred-tank reactors and pseudo-plug flow reactors treating a synthetic paper mill wastewater. Various filtration resistances were used to investigate membrane fouling characteristics, and molecular biology tools targeting 16S ribosomal DNA gene sequences were used to identify predominant bacterial populations in the sludges or attached to the fouled membranes. Filtration experiments using axenic cultures of Escherichia coli, Acinetobacter calcoaceticus, and Gordonia amarae were also performed to better understand the initiation and development of biofouling. The results showed that the tendency of membranes to biofoul depended upon membrane operating conditions as well as the properties of the activated sludge in the MBR systems. Specific bacterial populations, which were not dominant in the activated sludges, were selectively accumulated on the membrane surface leading to the development of irreversible biofouling.

  8. Enhancing anaerobic digestion of waste activated sludge by pretreatment: effect of volatile to total solids.

    Science.gov (United States)

    Wang, Xiao; Duan, Xu; Chen, Jianguang; Fang, Kuo; Feng, Leiyu; Yan, Yuanyuan; Zhou, Qi

    2016-01-01

    In this study the effect of volatile to total solids (VS/TS) on anaerobic digestion of waste activated sludge (WAS) pretreated by alkaline, thermal and thermal-alkaline strategies was studied. Experimental results showed that the production of methane from sludge was increased with VS/TS. When anaerobic digesters were fed with sludge pretreated by the thermal-alkaline method, the average methane yield was improved from 2.8 L/d at VS/TS 0.35 to 4.7 L/d at VS/TS 0.56. Also, the efficiency of VS reduction during sludge anaerobic digestion varied between 18.9% and 45.6%, and increased gradually with VS/TS. Mechanism investigation of VS/TS on WAS anaerobic digestion suggested that the general activities of anaerobic microorganisms, activities of key enzymes related to sludge hydrolysis, acidification and methanogenesis, and the ratio of Archaea to Bacteria were all increased with VS/TS, showing good agreement with methane production.

  9. GC/MS analysis of triclosan and its degradation by-products in wastewater and sludge samples from different treatments.

    Science.gov (United States)

    Tohidi, Fatemeh; Cai, Zongwei

    2015-08-01

    A gas chromatography/mass spectrometry (GC/MS)-based method was developed for simultaneous determination of triclosan (TCS) and its degradation products including 2,4-dichlorophenol (2,4-DCP), 2,8-dichlorodibenzo-p-dioxin (2,8-DCDD), and methyl triclosan (MTCS) in wastewater and sludge samples. The method provides satisfactory detection limit, accuracy, precision and recovery especially for samples with complicated matrix such as sewage sludge. Liquid-liquid extraction and accelerated solvent extraction (ASE) methods were applied for the extraction, and column chromatography was employed for the sample cleanup. Analysis was performed by GC/MS in the selected ion monitoring (SIM) mode. The method was successfully applied to wastewater and sludge samples from three different municipal wastewater treatment plants (WWTPs). Satisfactory mean recoveries were obtained as 91(±4)-106(±7)%, 82(±3)-87(±4)%, 86(±6)-87(±8)%, and 88(±4)-105(±3)% in wastewater and 88(±5)-96(±8)%, 84(±2)-87(±3)%, 84(±7)-89(±4)%, and 88(±3)-97(±5)% in sludge samples for TCS, 2,4-DCP, 2,8-DCDD, and MTCS, respectively. TCS degradation products were detected based on the type of the wastewater and sludge treatment. 2,8-DCDD was detected in the plant utilizing UV disinfection at the mean level of 20.3(±4.8) ng/L. 2,4-DCP was identified in chemically enhanced primary treatment (CEPT) applying chlorine disinfection at the mean level of 16.8(±4.5) ng/L). Besides, methyl triclosan (MTCS) was detected in the wastewater collected after biological treatment (10.7 ± 3.3 ng/L) as well as in sludge samples that have undergone aerobic digestion at the mean level of 129.3(±17.2) ng/g dry weight (dw).

  10. Characterization of functional microorganism groups and substrate in activated sludge and wastewater by AUR, NUR and OUR

    DEFF Research Database (Denmark)

    Kristensen, G. Holm; Jørgensen, P. Elberg; Henze, Mogens

    1992-01-01

    . The results indicated that influent biomass is of significance for the obtained fraction of denitrifiers to heterotrophs. For a separate nitrification stage activated sludge without denitrification a fraction of denitrifiers of 15-20% was found. The results of endogenous NUR and OUR determinations indicated...... that hydrolysis of activated sludge COD takes place with the same rate under anoxic and aerobic process conditions....

  11. Impact of solid retention time and nitrification capacity on the ability of activated sludge to remove pharmaceuticals

    DEFF Research Database (Denmark)

    Falås, Per; Andersen, Henrik Rasmus; Ledin, Anna

    2012-01-01

    . Parallel examinations of activated sludge batches with and without allylthiourea (12 mg/L), an inhibitor of ammonia monooxygenase, showed minor to moderate influence on the removal rates of ketoprofen and naproxen. These results suggest that the removal rates of biodegradable pharmaceuticals in municipal...... activated sludge processes are strongly linked to the heterotrophic bacteria community....

  12. Investigation of Sludge Batch 3 (Macrobatch 4) Glass Sample Anomalous Behavior

    Energy Technology Data Exchange (ETDEWEB)

    Bannochie, C. J.; Bibler, N. E.; Peeler, D. K.

    2005-08-15

    Two Defense Waste Processing Facility (DWPF) glass samples from Sludge Batch 3 (SB3) (Macrobatch 4) were received by the Savannah River National Laboratory (SRNL) on February 23, 2005. One sample, S02244, was designated for the Product Consistency Test (PCT) and elemental and radionuclide analyses. The second sample, S02247, was designated for archival storage. The samples were pulled from the melter pour stream during the feeding of Melter Feed Tank (MFT) Batch 308 and therefore roughly correspond to feed from Slurry Mix Evaporator (SME) Batches 306-308. During the course of preparing sample S02244 for PCT and other analyses two observations were made which were characterized as ''unusual'' or anomalous behavior relative to historical observations of glasses prepared for the PCT. These observations ultimately led to a series of scoping tests in order to determine more about the nature of the behavior and possible mechanisms. The first observation was the behavior of the ground glass fraction (-100 +200 mesh) for PCT analysis when contacted with deionized water during the washing phase of the PCT procedure. The behavior was analogous to that of an organic compound in the presence of water: clumping, floating on the water surface, and crawling up the beaker walls. In other words, the glass sample did not ''wet'' normally, displaying a hydrophobic behavior in water. This had never been seen before in 18 years SRNL PCT tests on either radioactive or non-radioactive glasses. Typical glass behavior is largely to settle to the bottom of the water filled beaker, though there may be suspended fines which result in some cloudiness to the wash water. The typical appearance is analogous to wetting sand. The second observation was the presence of faint black rings at the initial and final solution levels in the Teflon vessels used for the mixed acid digestion of S02244 glass conducted for compositional analysis. The digestion is composed

  13. Control of the aeration volume in an activated sludge process for nitrogen removal.

    Science.gov (United States)

    Samuelsson, P; Carlsson, B

    2002-01-01

    Biological nitrogen removal in an activated sludge process is obtained by two biological processes; nitrification and denitrification. Nitrifying bacteria need dissolved oxygen and a sufficiently large aeration volume for converting ammonium to nitrate in the wastewater. The objective of this paper is to develop an automatic control strategy for adjusting the aerated volume so that the effluent ammonium level can be kept close to a desired value despite major changes in the influent load. The strategy is based on applying exact linearization of the IAWO Activated Sludge Process Model No 1. Simulation results show that the suggested controller effectively attenuates process disturbances.

  14. Theoretical evaluation on nitrogen removal of step-feed anoxic/oxic activated sludge process

    Institute of Scientific and Technical Information of China (English)

    ZHU Gui-bing; PENG Yong-zhen

    2006-01-01

    Evaluation on nitrogen removal of step-feed anoxic/oxic activated sludge process at the standpoint of reaction kinetics and process kinetics was conducted. Theoretical biological nitrogen removal efficiency was deduced based on the mass balance of nitrate in the last stage. The comparison of pre-denitrification process and step feed process in the aspects of nitrogen removal efficiency, volume of reactor and building investment was studied, and the results indicated that step-feed anoxic/oxic activated sludge process was superior to pre-denitrification process in these aspects.

  15. Optimization of the do concentration in activated sludge systems treating petrochemical effluents

    Energy Technology Data Exchange (ETDEWEB)

    Van Haandel, A.; Cavalcanti, P. F.F.; Medeiros, U. T. P.

    2009-07-01

    Electric energy is normally one the important cost factors of activated sludge systems. If the aeration intensity is reduced, energy consumption will be lower, but the resulting reduction of the dissolved oxygen concentration in the mixed liquor may affect the treatment system in three ways: (1) reduction of the efficiency of organic material removal and nitrification, resulting in higher residual BOD, COD and NH{sub 3} concentrations in the effluent, (2) reduction of the metabolic activity of heterotrophic or auto trophic bacteria and (3) deterioration of the sludge settleability which may reduce the separation efficiency in the final settler. (Author)

  16. Impact of accelerated electrons on activating process and foaming potential of sludge

    Energy Technology Data Exchange (ETDEWEB)

    Cuba, V.; Pospisil, M. E-mail: mpospisil@br.fjfi.cvut.cz; Mucka, V.; Jenicek, P.; Silber, R.; Dohanyos, M.; Zabranska, J

    2003-06-01

    The process of activation is an important part of wastewater treatment technology. It can be affected in many ways, not least by using radiation. The paper describes effects of pre-irradiation of small part of biomass on activated sludge process. It has been shown, that relatively low dose of accelerated electrons can positively affect many parameters of the system.

  17. Activity, life time and effect of hydrolytic enzymes for enhanced biogas production from sludge anaerobic digestion.

    Science.gov (United States)

    Odnell, Anna; Recktenwald, Michael; Stensén, Katarina; Jonsson, Bengt-Harald; Karlsson, Martin

    2016-10-15

    As an alternative to energy intensive physical methods, enzymatic treatment of sludge produced at wastewater treatment plants for increased hydrolysis and biogas production was investigated. Several hydrolytic enzymes were assessed with a focus on how enzyme activity and life time was influenced by sludge environments. It could be concluded that the activity life time of added enzymes was limited (biogas in situ experiments, subtilisin at a 1% mixture on basis of volatile solids, was the only enzyme providing a significantly increased biomethane production of 37%. However, even at this high concentration, subtilisin could not hydrolyze all available substrate within the life time of the enzyme. Thus, for large scale implementation, enzymes better suited to the sludge environments are needed. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Biodegradation of toluene diamine (TDA) in activated sludge acclimated with aniline and TDA.

    Science.gov (United States)

    Asakura, S; Okazaki, S

    1995-06-01

    The biodegradability of toluene diamine (TDA) which has been regarded as a "recalcitrant compound" was examined in activated sludges. In this study, a microorganic-enzyme system which metabolized TDA was obtained by acclimating the activated sludge with aniline and TDA. In the sludge subject to be 200 days' acclimation, the considerable increase in respiration rate with the addition of TDA, accompanied the sharp decrease in its concentration. This indicated that TDA was metabolized fortuitously. The rate of biodegradation of TDA in the absence of aniline was first order with respect to its concentration when the initial TDA concentration was less than about 5 mg/l. The rate constant in this relation was proportional to mixed liquor suspended solid (MLSS). However, when the initial TDA concentration exceeded 5 mg/l, the plots were deviated from a first order rate equation.

  19. Waste activated sludge hydrolysis and acidification: A comparison between sodium hydroxide and steel slag addition.

    Science.gov (United States)

    Zhang, Ying; Zhang, Chaojie; Zhang, Xuan; Feng, Leiyu; Li, Yongmei; Zhou, Qi

    2016-10-01

    Alkaline treatment with steel slag and NaOH addition were investigated under different pH conditions for the fermentation of waste activated sludge. Better performance was achieved in steel slag addition scenarios for both sludge hydrolysis and acidification. More solubilization of organic matters and much production of higher VFA (volatile fatty acid) in a shorter time can be achieved at pH10 when adjusted by steel slag. Higher enzyme activities were also observed in steel slag addition scenarios under the same pH conditions. Phosphorus concentration in the supernatant increased with fermentation time and pH in NaOH addition scenarios, while in contrast most phosphorus was released and captured by steel slag simultaneously in steel slag addition scenarios. These results suggest that steel slag can be used as a substitute for NaOH in sludge alkaline treatment.

  20. Zero-valent iron enhanced methanogenic activity in anaerobic digestion of waste activated sludge after heat and alkali pretreatment.

    Science.gov (United States)

    Zhang, Yaobin; Feng, Yinghong; Quan, Xie

    2015-04-01

    Heat or alkali pretreatment is the effective method to improve hydrolysis of waste sludge and then enhance anaerobic sludge digestion. However the pretreatment may inactivate the methanogens in the sludge. In the present work, zero-valent iron (ZVI) was used to enhance the methanogenic activity in anaerobic sludge digester under two methanogens-suppressing conditions, i.e. heat-pretreatment and alkali condition respectively. With the addition of ZVI, the lag time of methane production was shortened, and the methane yield increased by 91.5% compared to the control group. The consumption of VFA was accelerated by ZVI, especially for acetate, indicating that the acetoclastic methanogenesis was enhanced. In the alkali-condition experiment, the hydrogen produced decreased from 27.6 to 18.8 mL when increasing the ZVI dosage from 0 to 10 g/L. Correspondingly, the methane yield increased from 1.9 to 32.2 mL, which meant that the H2-utilizing methanogenes was enriched. These results suggested that the addition of ZVI into anaerobic digestion of sludge after pretreated by the heat or alkali process could efficiently recover the methanogenic activity and increase the methane production and sludge reduction.

  1. 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

    Full Text Available BACKGROUND: The increasing use of multiwalled carbon nanotubes (MWCNTs will inevitably lead to the exposure of wastewater treatment facilities. However, knowledge of the impacts of MWCNTs on wastewater nutrient removal and bacterial community structure in the activated sludge process is sparse. AIMS: To investigate the effects of MWCNTs on wastewater nutrient removal, and bacterial community structure in activated sludge. METHODS: Three triplicate sequencing batch reactors (SBR were exposed to wastewater which contained 0, 1, and 20 mg/L MWCNTs. MiSeq sequencing was used to investigate the bacterial community structures in activated sludge samples which were exposed to different concentrations of MWCNTs. RESULTS: Exposure to 1 and 20 mg/L MWCNTs had no acute (1 day impact on nutrient removal from wastewater. After long-term (180 days exposure to 1 mg/L MWCNTs, the average total nitrogen (TN removal efficiency was not significantly affected. TN removal efficiency decreased from 84.0% to 71.9% after long-term effects of 20 mg/L MWCNTs. After long-term exposure to 1 and 20 mg/L MWCNTs, the total phosphorus removal efficiencies decreased from 96.8% to 52.3% and from 98.2% to 34.0% respectively. Further study revealed that long-term exposure to 20 mg/L MWCNTs inhibited activities of ammonia monooxygenase and nitrite oxidoreductase. Long-term exposure to 1 and 20 mg/L MWCNTs both inhibited activities of exopolyphosphatase and polyphosphate kinase. MiSeq sequencing data indicated that 20 mg/L MWCNTs significantly decreased the diversity of bacterial community in activated sludge. Long-term exposure to 1 and 20 mg/L MWCNTs differentially decreased the abundance of nitrifying bacteria, especially ammonia-oxidizing bacteria. The abundance of PAOs was decreased after long-term exposure to 20 mg/L MWCNTs. The abundance of glycogen accumulating organisms (GAOs was increased after long-term exposure to 1 mg/L MWCNTs. CONCLUSION: MWCNTs have adverse effects on

  2. Fractionation of biogas plant sludge material improves metaproteomic characterization to investigate metabolic activity of microbial communities.

    Science.gov (United States)

    Kohrs, Fabian; Wolter, Sophie; Benndorf, Dirk; Heyer, Robert; Hoffmann, Marcus; Rapp, Erdmann; Bremges, Andreas; Sczyrba, Alexander; Schlüter, Andreas; Reichl, Udo

    2015-10-01

    With the development of high resolving mass spectrometers, metaproteomics evolved as a powerful tool to elucidate metabolic activity of microbial communities derived from full-scale biogas plants. Due to the vast complexity of these microbiomes, application of suitable fractionation methods are indispensable, but often turn out to be time and cost intense, depending on the method used for protein separation. In this study, centrifugal fractionation has been applied for fractionation of two biogas sludge samples to analyze proteins extracted from (i) crude fibers, (ii) suspended microorganisms, and (iii) secreted proteins in the supernatant using a gel-based approach followed by LC-MS/MS identification. This fast and easy method turned out to be beneficial to both the quality of SDS-PAGE and the identification of peptides and proteins compared to untreated samples. Additionally, a high functional metabolic pathway coverage was achieved by combining protein hits found exclusively in distinct fractions. Sample preparation using centrifugal fractionation influenced significantly the number and the types of proteins identified in the microbial metaproteomes. Thereby, comparing results from different proteomic or genomic studies, the impact of sample preparation should be considered. All MS data have been deposited in the ProteomeXchange with identifier PXD001508 (http://proteomecentral.proteomexchange.org/dataset/PXD001508).

  3. Effect of TiO2 nanoparticles on UASB biomass activity and dewatered sludge.

    Science.gov (United States)

    Yadav, Tushar; Mungray, Alka A; Mungray, Arvind K

    2017-02-01

    The accumulation of the nanowastes in the wastewater treatment plants has raised several concerns; therefore, it is an utmost priority to study the nanoparticle (NP) toxicity in such systems. In this work, the effect of TiO2 NPs on up-flow anaerobic sludge blanket (UASB) microflora and their photocatalytic effect on dewatered sludge were studied. We observed 99.98% removal of TiO2 NPs by sludge biomass within 24 h, though negligible toxicity was found up to 100 mg/L TiO2 concentration on extracellular polymeric substances (EPS), volatile fatty acid and biogas generation. The low toxicity corresponds to the agglomeration of TiO2 NPs in UASB sludge. Alterations in dewatered sludge biochemical composition and increase in cell damage were observed upon exposure to sunlight as evidenced by FTIR and fluorescent microscopy, respectively. Results suggest the negligible toxicity of TiO2 NPs on UASB biomass activity; however, once exposed to open environment and sunlight, they may exert detrimental effects.

  4. Research for waste water treatment technology with low production of excessive active sludge

    Directory of Open Access Journals (Sweden)

    Makisha Nikolay

    2017-01-01

    Full Text Available The article reflects the possibility to create a technological scheme of waste water treatment of domestic and similar type of sewage within minimal amount of excessive active sludge by means of bioreactors with immobilized feed. There are various aspects to be considered: technical, economic, social and ecological. According to the above it is strongly needed to provide a combination of proper waste water treatment, minimal sludge formation and the possibility for a further use of the sludge. One of the ways to achieve the goal above is to use an immobilized feed in the aeration tank. The necessary experiments were carried out in the department of waste water treatment and water ecology. The article includes the scheme of the facility and other parameters of the experiments, which has been carried. The combination of aerobic and anaerobic processes helps to provide proper quality of integrated biological treatment. Chambers of the aeration reactor were also equipped with the polymer feed of various structures. The sludge treatment that was also strongly needed was made by means of aerobic stabilization with the use of ejecting aeration. The results of experiment showed a good effect in both components – sewage and sludge treatment. Afterwards there was also an industrial model launched which confirmed the results of the previous stage.

  5. Production from Activated Sludge Process of Sago Industry Wastewater Using Central Composite Design

    Directory of Open Access Journals (Sweden)

    B. Subha

    2012-01-01

    Full Text Available Sago industries effluent containing large amounts of organic content produced excess sludge which is a serious problem in wastewater treatment. In this study ozonation has been employed for the reduction of excess sludge production in activated sludge process. Central composite design is used to study the effect of ozone treatment for the reduction of excess sludge production in sago effluent and to optimise the variables such as pH, ozonation time, and retention time. ANOVA showed that the coefficient determination value (R2 of VSS and COD reduction were 0.9689 and 0.8838, respectively. VSS reduction (81% was achieved at acidic pH 6.9, 12 minutes ozonation, and retention time of 10 days. COD reduction (87% was achieved at acidic pH 6.7, 8 minutes of ozonation time, and retention time of 6 days. Low ozonation time and high retention time influence maximum sludge reduction, whereas low ozonation time with low retention time was effective for COD reduction.

  6. Use of Lecane rotifers for limiting Thiothrix filamentous bacteria in bulking activated sludge in a dairy wastewater treatment plant

    Directory of Open Access Journals (Sweden)

    Kowalska Ewa

    2014-01-01

    Full Text Available Excessive growth of filamentous bacteria is a serious problem in many dairy wastewater treatment plants (WWTPs. The objective of the study was to determine whether Lecane inermis rotifers were able to reduce the density of Thiothrix bacteria in activated sludge originating from a dairy WWTP, as well as to identify the impact of rotifers on other organisms in sludge. On a laboratory scale, three experiments were conducted in which activated sludge with a predominance of Thiothrix was inoculated with rotifers at an initial concentration of app. 600 individuals/mL. The results showed that the rotifers, by feeding on the bacterium filaments, are able to reduce significantly the quantity of Thiothrix. A decline in Thiothrix abundance coincided with an improvement of the sedimentation properties of activated sludge. In addition, it was proven that Lecane inermis did not negatively affect the number of Protozoa and Metazoa in activated sludge.

  7. Evaluation of the functional activity of activated sludge from local waste water treatment plant in the Arctic region

    Directory of Open Access Journals (Sweden)

    Il'inskiy V. V.

    2017-03-01

    Full Text Available The paper considers characteristics of the activated sludge in the local wastewater treatment plant (LWTP and its ability to purify fully domestic sewage water in the Far North. Biochemical process of destruction of organic pollutants is influenced by a microbial complex functioning in aeration tanks. Taking into account climatic conditions of the region where the organic matter degradation processes are slowed, and lack of control over the operation, efficiency and occupational safety of LWTPs, it seems to be important to study the physiological characteristics of the bacteria used in bioremediation, and their ability to maximize the purifying domestic sewage in the Arctic region. Undue intervention in the biosphere systems leads to disruption of the balance of internal and external ecosystems communications. The goal of research is studying structural determination and functioning of activated sludge bacteriocenosis of LWTP TOPAS-5 (GK "Topol-ECO" in certain physical and chemical conditions of the habitat, and establishing completeness of cleaning process in this treatment plant. The paper considers the structure (quantitative and qualitative composition and function of LWTP activated sludge bacteriocenosis functioning in the Arctic region. The estimation of the activated sludge of full waste water treatment process of the LWTP has been given. The research's results have allowed to identify and determine the bacterial count of physiological groups of microorganisms purified domestic sewage; to isolate from activated sludge the bioflocculant-producing microorganisms' on the experimental medium; to evaluate efficiency of LWTP work in the Arctic region

  8. Optimization and/or acclimatization of activated sludge process under heavy metals stress.

    Science.gov (United States)

    El Bestawy, Ebtesam; Helmy, Shacker; Hussein, Hany; Fahmy, Mohamed

    2013-04-01

    The present study aimed to overcome the toxicity of the heavy metals load, discharged with the industrial effluents into Alexandria sewerage network, on the activated sludge treatment system through effective acclimation for organic matter and heavy metals removal. Optimization and/or acclimatization of the activated sludge process in the presence of Cu, Cd, Co and Cr contaminating mixed domestic-industrial wastewater was investigated. Acclimatization process was performed through abrupt and stepwise addition of tested metals using sequencing batch reactors treatment approach and evaluated as microbial oxygen uptake rate (OUR), dehydrogenase activity (DHA), organic matter (COD) and heavy metals removal. Abrupt addition of metals adversely affected sludge bioactivity leading to decline in the removal efficiency of the targeted contaminants and loss of floc structure. Metals IC50 confirmed that copper possessed the highest toxicity towards the OUR, DHA activity and COD removal with orders Cu > Cd > Cr > Co; Cu > Cd > Co = Cr and Cu > Cd > Cr > Co, respectively. The highest metal removal was recorded for Cd followed by Co, Cu and finally Cr, most of which was retained in the dissolved influent. However, controlled stepwise application of the tested metals exhibited high sensitivity of DHA and OUR activities only at the highest metal concentrations although enhanced at the lowest concentrations while COD removal was not significantly affected. In conclusion, this approach resulted in adaptation of the system where sludge microbes acquired and developed natural resistance to such metals leading to remarkable enhancement of both organic matter and heavy metals removal.

  9. Active source requirements for assay of sludge drums on the BIR WIT system

    Energy Technology Data Exchange (ETDEWEB)

    Roberson, G.P.; Camp, D.C.

    1998-04-27

    The design of the active source for active and passive computed tomography (A&PCT) is critical with respect to accuracy and throughput. The A&PCT active source requirements are highly dependent upon the attenuation properties of the waste matrix within the drum. On of the most highly attenuating waste matrices is sludge. This waste stream will consist of solidified aqueous waste consisting of IDC 001 first stage sludge and IDC 007 wet sludge. Also, the stream consists of solidified organic waste known as code IDC 003 organic setups. We have evaluated the sludge drum data that was previously acquired on the WIT system and have determined that the active source activity must be increased to provide reasonable throughput. The sludge drum that is evaluated here is drum CEPRF11. CEPRF11 is a test drum that was part of the Nondestructive Assay system Capability Evaluation Project (CEP) and contained an actual Rocky Flats waste that is categorized as code 003 solidified organic waste. The full drum was evaluated and found to be somewhat homogenous; therefore, a single slice is arbitrarily chosen to represent the entire drum. Slice number 8 is used and is located approximately at the center of the drum. Figure 1 shows the averaged projections for different energies derived from the active sinogram of slice number 8 from the CEPRF11 drum. This is the average of all the projections of slice 8 taken over 180 degrees with an active integration time of 6 seconds. Figure 2 is also a graph showing the average of all the projections for slice 8; however, the active integration time is 30 seconds.

  10. Identification of Triclosan-O-Sulfate and other transformation products of Triclosan formed by activated sludge.

    Science.gov (United States)

    Chen, Xijuan; Casas, Mònica Escolà; Nielsen, Jeppe Lund; Wimmer, Reinhard; Bester, Kai

    2015-02-01

    Aerobic degradation experiments of Triclosan were performed in activated sludge to identify possible transformation products for this compound. During 7 days, the formation of biotransformation products such as 2,4-Dichlorophenol, 4-Chlorocatechol, 5-Hydroxy-Triclosan and other Monohydroxy-Triclosan derivatives as well as Dihydroxy-Triclosan-derivatives were observed. The structure of 5-Hydroxy-Triclosan was elucidated by NMR data for the first time in sludge degradation experiments. Additionally the production of a hitherto unknown transformation product in sludge, i.e., Triclosan-O-Sulfate was detected. During the incubations, the concentrations of this transformation product changed from zero to 330 μg L(-1). Based on the analysis of the biodegradation products, three types of reactions were identified: 1) chemical scission of ether bond to form phenols and catechols, 2) addition of OH moieties to the aromatic ring, and 3) adding of methyl or sulfate groups to the original hydroxyl group.

  11. Biomass density and filament length synergistically affect activated sludge settling: systematic quantification and modeling.

    Science.gov (United States)

    Jassby, D; Xiao, Y; Schuler, A J

    2014-01-01

    Settling of the biomass produced during biological treatment of wastewater is a critical and often problematic process. Filamentous bacteria content is the best-known factor affecting biomass settleability in activated sludge wastewater treatment systems, and varying biomass density has recently been shown to play an important role as well. The objective of this study was to systematically determine how filament content and biomass density combine to affect microbial biomass settling, with a focus on density variations over the range found in full-scale systems. A laboratory-scale bioreactor system was operated to produce biomass with a range of filamentous bacterium contents. Biomass density was systematically varied in samples from this system by addition of synthetic microspheres to allow separation of filament content and density effects on settleability. Fluorescent in-situ hybridization indicated that the culture was dominated by Sphaerotilus natans, a common contributor to poor settling in full-scale systems. A simple, image-based metric of filament content (filament length per floc area) was linearly correlated with the more commonly used filament length per dry biomass measurement. A non-linear, semi-empirical model of settleability as a function of filament content and density was developed and evaluated, providing a better understanding of how these two parameters combine to affect settleability. Filament content (length per dry biomass weight) was nearly linearly related to sludge volume index (SVI) values, with a slightly decreasing differential, and biomass density exhibited an asymptotic relationship with SVI. The filament content associated with bulking was shown to be a function of biomass density. The marginal effect of filament content on settleability increased with decreasing biomass density (low density biomass was more sensitive to changes in filament content than was high density biomass), indicating a synergistic relationship between these

  12. Modeling integrated fixed-film activated sludge and moving-bed biofilm reactor systems II: evaluation.

    Science.gov (United States)

    Boltz, Joshua P; Johnson, Bruce R; Daigger, Glen T; Sandino, Julian; Elenter, Deborah

    2009-06-01

    A steady-state model presented by Boltz, Johnson, Daigger, and Sandino (2009) describing integrated fixed-film activated sludge (IFAS) and moving-bed biofilm reactor (MBBR) systems has been demonstrated to simulate, with reasonable accuracy, four wastewater treatment configurations with published operational data. Conditions simulated include combined carbon oxidation and nitrification (both IFAS and MBBR), tertiary nitrification MBBR, and post denitrification IFAS with methanol addition as the external carbon source. Simulation results illustrate that the IFAS/MBBR model is sufficiently accurate for describing ammonia-nitrogen reduction, nitrate/nitrite-nitrogen reduction and production, biofilm and suspended biomass distribution, and sludge production.

  13. TREATMENT OF TEXTILE WASTEWATER USING A CONTINUOUS FLOW ACTIVATED SLUDGE SYSTEM AT PILOT-SCALE

    Directory of Open Access Journals (Sweden)

    M. A. ABOULHASSAN

    2014-11-01

    Full Text Available Textile industry wastewaters contain high concentrations of organic matter, toxic substances and dyes and pigments, and are harmful to receiving environment. Activated sludge system at pilot scale with continuous feeding, was used for the treatment of a dyeing unit effluent. The results showed that treatment allows a removal rate of 40-56 % of chemical oxygen demand (COD, and 13 to 30 % of color. The adsorption on sludge appears to be the main process responsible for the color removal of wastewater generated by textile industry.

  14. Degradation of PPCPs in activated sludge from different WWTPs in Denmark

    DEFF Research Database (Denmark)

    Chen, Xijuan; Vollertsen, Jes; Nielsen, Jeppe Lund

    2015-01-01

    was performed to assess the removal of frequently occurring pharmaceuticals (Naproxen, Fenoprofen, Ketoprofen, Dichlofenac, Carbamazepine) and the biocide Triclosan in activated sludge from four different Danish WWTPs. The respective degradation constants were compared to operational parameters previous shown...... to be of importance for degradation of micropollutants such as biomass concentration, and sludge retention time (SRT). The most rapid degradation, was observed for NSAID pharmaceuticals (55–90 % for Fenoprofen, 77–94 % for Ketoprofen and 46–90 % for Naproxen), followed by Triclosan (61–91 %), while Dichlofenac...

  15. Use of lysis and recycle to control excess sludge production in activated sludge treatment: bench scale study and effect of chlorinated organic compounds.

    Science.gov (United States)

    Nolasco, M A; Campos, A L O; Springer, A M; Pires, E C

    2002-01-01

    The most widely used treatment system in the pulp and paper industry--the activated sludge--produces high quantities of sludge which need proper disposal. In this paper a modified activated sludge process is presented. A synthetic wastewater, prepared to simulate the effluent of bleached and unbleached pulp and paper plant wastewater, was submitted to treatment in a bench scale aerobic reactor. The excess sludge was lysed in a mechanical mill--Kaddy mill--and totally recycled to the aeration tank. In the first phase the synthetic wastewater, without the chlorinated compounds, was fed to the reactor. In the second phase increasing dosages of the chlorinated compounds were used. Total recycle of excess sludge after disintegration did not produce adverse effects. During the first phase average COD removal efficiency was 65% for the control unit, which operated in a conventional way, and 63% for the treatment unit, which operated with total recycle. During the second phase the COD removal efficiency increased to 77% in the control unit and 75% in the treatment unit. Chlorinated organics removal was 85% in the treatment unit and 86% for the control unit. These differences are not significant.

  16. Effect of process variables on the production of Polyhydroxyalkanoates by activated sludge

    Directory of Open Access Journals (Sweden)

    Mokhtarani Nader

    2012-09-01

    Full Text Available Abstract Polyhydroxyalkanoates are known to be temporarily stored by microorganisms in activated sludge, especially in anaerobic-aerobic processes. Due to the problems resulted from the disposals of plastic wastes and excess sludge of wastewater treatment plants, the production of polyhydroxyalkanoates by treating activated sludge and determining the effect of process variables were the main issues of this paper. In this research, an anaerobic-aerobic sequencing batch reactor was used to make microorganism adapted and a batch aerobic reactor was used for enriching them. The variables affecting polyhydroxyalkanoates production including aeration time, sludge retention time, and volatile fatty acids concentration of the influent in sequencing batch reactor, and also carbon to nitrogen ratio and cultivation time in polymer production reactor, were investigated using Taguchi statistical approach to determine optimum conditions. The maximum polymer production of 29% was achieved at sludge retention time of 5–10 days, aeration time of 2 hours, supplementation of 40% of volatile fatty acids in the influent and increasing of carbon to nitrogen ratio of polymer production reactor to above 25 g/g. Based on the results, in optimum conditions, the volatile fatty acids concentration which increased the production of polyhydroxyalkanoates up to 49% was the most effective variable. Carbon to nitrogen ratio, sludge retention time and aeration time were ranked as the next affecting parameters. Although the polyhydroxyalkanoates content achieved in present study is much lower than that by pure culture, but the proposed method may still serve well as an environmental friendly means to convert waste into valuable product.

  17. Effect of Process Variables on the Production of Polyhydroxyalkanoates by Activated Sludge

    Directory of Open Access Journals (Sweden)

    Nader Mokhtarani

    2012-09-01

    Full Text Available Polyhydroxyalkanoates are known to be temporarily stored by microorganisms in activated sludge, especially in anaerobic-aerobic processes. Due to the problems resulted from the disposals of plastic wastes and excess sludge of wastewater treatment plants, the production of polyhydroxyalkanoates by treating activated sludge anddetermining the effect of process variables were the main issues of this paper. In this research, an anaerobic-aerobic sequencing batch reactor was used to make microorganism adapted and a batch aerobic reactor was used for enriching them. The variables affecting polyhydroxyalkanoates production including aeration time, sludge retention time, and volatile fatty acids concentration of the influent in sequencing batch reactor, and also carbon to nitrogenratio and cultivation time in polymer production reactor, were investigated using Taguchi statistical approach to determine optimum conditions. The maximum polymer production of 29% was achieved at sludge retention time of 5–10 days, aeration time of 2 hours, supplementation of 40% of volatile fatty acids in the influent and increasing of carbon to nitrogen ratio of polymer production reactor to above 25 g/g. Based on the results, in optimum conditions, the volatile fatty acids concentration which increased the production of polyhydroxyalkanoates up to 49% was the most effective variable. Carbon to nitrogen ratio, sludge retention time and aeration time were ranked as the next affecting parameters. Although the polyhydroxyalkanoates content achieved in present study is muchlower than that by pure culture, but the proposed method may still serve well as an environmental friendly means to convert waste into valuable product.

  18. Effect of Volatile Fatty Acids and Trimethylamine on Nitrification in Activated Sludge

    DEFF Research Database (Denmark)

    Eilersen, Ann Marie; Henze, Mogens; Kløft, Lene

    1994-01-01

    The effect of volatile fatty acids and trimethylamine on the nitrification activity of activated sludge was studied in laboratory batch experiments. The critical concentration of inhibitor IK at which the activity ceases was determined by modelling. IK values for ammonia oxidation were found...... wastewater stripped of sulphide showed that volatile fatty acids and trimethylamine alone cannot account for the inhibition of the nitrification activity, indicating that other factors are also involved....

  19. Control and identification in activated sludge processes = Regeling en identifikatie in aktief-slib processen

    NARCIS (Netherlands)

    Lukasse, L.

    1999-01-01

    This thesis is about control and identification in activated sludge processes (ASP's). The chapters in this thesis are divided in two parts. Part I deals with the development of the best feasible, close-to-optimal adaptive receding horizon optimal controller (RHOC) for N-removal in a contin

  20. Dosing of anaerobic granular sludge bioreactors with cobalt: Impact of cobalt retention on methanogenic activity

    KAUST Repository

    Fermoso, Fernando G.

    2010-12-01

    The effect of dosing a metal limited anaerobic sludge blanket (UASB) reactor with a metal pulse on the methanogenic activity of granular sludge has thus far not been successfully modeled. The prediction of this effect is crucial in order to optimize the strategy for metal dosage and to prevent unnecessary losses of resources. This paper describes the relation between the initial immobilization of cobalt in anaerobic granular sludge cobalt dosage into the reactor and the evolution of methanogenic activity during the subsequent weeks. An operationally defined parameter (A0· B0) was found to combine the amount of cobalt immobilized instantaneously upon the pulse (B0) and the amount of cobalt immobilized within the subsequent 24. h (A0). In contrast with the individual parameters A0 and B0, the parameter A0· B0 correlated significantly with the methanogenic activity of the sludge during the subsequent 16 or 35. days. This correlation between metal retention and activity evolution is a useful tool to implement trace metal dosing strategies for biofilm-based biotechnological processes. © 2010.

  1. Biodegradation of pharmaceuticals in hospital wastewater by a hybrid biofilm and activated sludge system (Hybas)

    DEFF Research Database (Denmark)

    Escola Casas, Monica; Chhetri, Ravi Kumar; Ooi, Gordon Tze Hoong

    2015-01-01

    Hospital wastewater contributes a significant input of pharmaceuticals into municipal wastewater. The combination of suspended activated sludge and biofilm processes, as stand-alone or as hybrid process, has been suggested as a possible solution for hospital wastewater treatment. HybasTM is a hyb...

  2. Bacterial community analysis of activated sludge: an evaluation of four commonly used DNA extraction methods

    NARCIS (Netherlands)

    Vanysacker, L.; Declerck, S.A.J.; Hellemans, B.; De Meester, L.; Vankelecom, I.; Declerck, P.

    2010-01-01

    The effectiveness of three commercially available direct DNA isolation kits (Mobio, Fast, Qiagen) and one published direct DNA extraction protocol (Bead) for extracting bacterial DNA from different types of activated sludge was investigated and mutually compared. The DNA quantity and purity were

  3. Start-up of anaerobic ammonia oxidation bioreactor with nitrifying activated sludge

    Institute of Scientific and Technical Information of China (English)

    ZHENG Ping; LIN Feng-mei; HU Bao-lan; CHEN Jian-song

    2004-01-01

    The anaerobic ammonia oxidation(Anammox) bioreactor was successfully started up with the nitrifying activated sludge. After anaerobically operated for 105 d, the bioreactor reached a good performance with removal percentage of both ammonia and nitrite higher high efficiency and stability because it held a large amount of biomass in the bioreactor.

  4. Wastewater and Biomass Characterization for the Activated Sludge Model No. 2: Biological Phosphorus Removal

    DEFF Research Database (Denmark)

    Henze, Mogens; Gujer, W.; Mino, T.

    1995-01-01

    The characterization of wastewater and biomass in relation to the Activated Sludge Model No. 2 is described. A new fraction of organic fermentable matter is needed. Phosphate accumulating organisms and their structural compounds polyphosphate and polyhydroxyalkanoate have to be included in the bi...

  5. Combined removal of sulfur compounds and nitrate by autotrophic denitrication in bioaugmented activated sludge system

    NARCIS (Netherlands)

    Manconi, I.; Carucci, A.; Lens, P.N.L.

    2007-01-01

    An autotrophic denitrification process using reduced sulfur compounds (thiosulfate and sulfide) as electron donor in an activated sludge system is proposed as an efficient and cost effective alternative to conventional heterotrophic denitrification for inorganic (or with low C/N ratio) wastewaters a

  6. Wastewater and Biomass Characterization for the Activated Sludge Model No. 2: Biological Phosphorus Removal

    DEFF Research Database (Denmark)

    Henze, Mogens; Gujer, W.; Mino, T.

    1995-01-01

    The characterization of wastewater and biomass in relation to the Activated Sludge Model No. 2 is described. A new fraction of organic fermentable matter is needed. Phosphate accumulating organisms and their structural compounds polyphosphate and polyhydroxyalkanoate have to be included in the bi...

  7. Control and identification in activated sludge processes = Regeling en indentifikatie in aktief-slib processen

    NARCIS (Netherlands)

    Lukasse, L.

    1999-01-01

    This thesis is about control and identification in activated sludge processes (ASP's). The chapters in this thesis are divided in two parts. Part I deals with the development of the best feasible, close-to-optimal adaptive receding horizon optimal controller (RHOC) for N-removal in a continuously mi

  8. Control and identification in activated sludge processes = Regeling en identifikatie in aktief-slib processen

    NARCIS (Netherlands)

    Lukasse, L.

    1999-01-01

    This thesis is about control and identification in activated sludge processes (ASP's). The chapters in this thesis are divided in two parts. Part I deals with the development of the best feasible, close-to-optimal adaptive receding horizon optimal controller (RHOC) for N-removal in a

  9. Bacterial community analysis of activated sludge: an evaluation of four commonly used DNA extraction methods

    NARCIS (Netherlands)

    Vanysacker, L.; Declerck, S.A.J.; Hellemans, B.; De Meester, L.; Vankelecom, I.; Declerck, P.

    2010-01-01

    The effectiveness of three commercially available direct DNA isolation kits (Mobio, Fast, Qiagen) and one published direct DNA extraction protocol (Bead) for extracting bacterial DNA from different types of activated sludge was investigated and mutually compared. The DNA quantity and purity were det

  10. Bioavailable and biodegradable dissolved organic nitrogen in activated sludge and trickling filter wastewater treatment plants

    Science.gov (United States)

    A study was carried out to understand the fate of biodegradable dissolved organic nitrogen (BDON) and bioavailable dissolved organic nitrogen (ABDON) along the treatment trains of a wastewater treatment facility (WWTF) equipped with an activated sludge (AS) system and a WWTF equipped with a two-stag...

  11. Mesophilic and thermophilic alkaline fermentation of waste activated sludge for hydrogen production: Focusing on homoacetogenesis

    DEFF Research Database (Denmark)

    Wan, Jingjing; Jing, Yuhang; Zhang, Shicheng;

    2016-01-01

    The present study compared the mesophilic and thermophilic alkaline fermentation of waste activated sludge (WAS) for hydrogen production with focus on homoacetogenesis, which mediated the consumption of H2 and CO2 for acetate production. Batch experiments showed that hydrogen yield of WAS increased...

  12. 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.

    2006-01-01

    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

  13. Immobilization study of biosorption of heavy metal ions onto activated sludge

    Institute of Scientific and Technical Information of China (English)

    WU Hai-suo; ZHANG Ai-qiang; WANG Lian-sheng

    2004-01-01

    Activated sludge was immobilized into Ca-alginate beads via entrapment, and biosorption of three heavy metal ions, copper(Ⅱ), zinc(Ⅱ), and chromimum(Ⅱ), from aqueous solution in the concentration range of 10-100 mg/L was studied by using both entrapped activated sludge and inactivated free biomass at pH≤ 5. A biphasic metal adsorption pattern was observed in all immobilized biomass experiments. The biosorption of metal ions by the biosorbents increased with the initial concentration increased in the medium. The adsorption rate of immobilized pretreated activated sludge(PAS) was much lower than that of free PAS due to the increase in mass transfer resistance resulting from the polymeric matrix. Biosorption equilibrium of beads was established in about 20 h and the adsorbed heavy metal ions did not change further with time. No significant effect of temperature was observed in the test for free biomass while immobilized PAS appeared to be strong temperature dependent in the test range of 10 and 40℃.Besides, the content of activated sludge in the calcium alginate bead has an influence on the uptake of heavy metals. The sorption equilibrium was well modeled by Langmuir isotherm, implying monomolecular adsorption mechanism. Carboxyl group in cell wall played an important role in surface adsorption of heavy metal ions on PAS.

  14. Bioremediation of heavy metal-contaminated effluent using optimized activated sludge bacteria

    Science.gov (United States)

    Bestawy, Ebtesam El.; Helmy, Shacker; Hussien, Hany; Fahmy, Mohamed; Amer, Ranya

    2013-03-01

    Removal of heavy metals from contaminated domestic-industrial effluent using eight resistant indigenous bacteria isolated from acclimatized activated sludge was investigated. Molecular identification using 16S rDNA amplification revealed that all strains were Gram-negative among which two were resistant to each of copper, cadmium and cobalt while one was resistant to each of chromium and the heavy metal mixture. They were identified as Enterobacter sp. (Cu1), Enterobacter sp. (Cu2), Stenotrophomonas sp. (Cd1), Providencia sp. (Cd2), Chryseobacterium sp. (Co1), Comamonas sp. (Co2), Ochrobactrum sp. (Cr) and Delftia sp. (M1) according to their resistance pattern. Strains Cu1, Cd1, Co2 and Cr were able to resist 275 mg Cu/l, 320 mg Cd/l, 140 mg Co/l and 29 mg Cr/l respectively. The four resistant strains were used as a mixture to remove heavy metals (elevated concentrations) and reduce the organic load of wastewater effluent. Results revealed that using the proposed activated sludge with the resistant bacterial mixture was more efficient for heavy metal removal compared to the activated sludge alone. It is therefore recommended that the proposed activated sludge system augmented with the acclimatized strains is the best choice to ensure high treatment efficiency and performance under metal stresses especially when industrial effluents are involved.

  15. Mesophilic and thermophilic activated sludge post-treatment of paper mill process water

    NARCIS (Netherlands)

    Vogelaar, J.C.T.; Bouwhuis, E.; Klapwijk, A.; Spanjers, H.; Lier, van J.B.

    2002-01-01

    Increasing system closure in paper mills and higher process water temperatures make the applicability of thermophilic treatment systems increasingly important. The use of activated sludge as a suitable thermophilic post-treatment system for anaerobically pre-treated paper process water from a paper

  16. A new method study biodegradation kinetics of anorganic trace pollutants by activated sludge

    NARCIS (Netherlands)

    Temmink, H.; Klapwijk, A.

    2003-01-01

    A reliable prediction of the behaviour of organic trace compounds in activated sludge plants requires an accurate input of the biodegradation kinetics. Often these kinetics are extrapolated from the results of standardised biodegradation tests. However, these tests generally are not designed to

  17. A new method study biodegradation kinetics of anorganic trace pollutants by activated sludge

    NARCIS (Netherlands)

    Temmink, H.; Klapwijk, A.

    2003-01-01

    A reliable prediction of the behaviour of organic trace compounds in activated sludge plants requires an accurate input of the biodegradation kinetics. Often these kinetics are extrapolated from the results of standardised biodegradation tests. However, these tests generally are not designed to yiel

  18. An international survey of decabromodiphenyl ethane (deBDethane) and decabromodiphenyl ether (decaBDE) in sewage sludge samples.

    Science.gov (United States)

    Ricklund, Niklas; Kierkegaard, Amelie; McLachlan, Michael S

    2008-12-01

    Decabromodiphenyl ethane (deBDethane) is an additive flame retardant marketed as a replacement for decabromodiphenyl ether (decaBDE). The structures of the two chemicals are similar, and hence deBDethane may also become an environmental contaminant of concern. Environmental data on deBDethane are scarce. Since sewage sludge is an early indicator of leakage of these chemicals into the environment, an international survey of deBDethane and decaBDE levels in sludge was conducted. Samples were collected from 42 WWTPs in 12 different countries and analyzed with GC/LRMS. DeBDethane was present in sludge from all countries and may therefore be a worldwide concern. The levels of deBDethane in sludge samples from the Ruhr area of Germany were the highest so far reported in the literature (216 ng g(-1)d.wt.). The [deBDethane]/[decaBDE] quotient for the whole data set ranged from 0.0018 to 0.83. High ratios were found in and around Germany where deBDethane imports are known to have been high and substitution of decaBDE with deBDethane is likely to have occurred. Low ratios were found in the USA and the UK, countries that have traditionally been large users of decaBDE. An estimate of the flux of deBDEthane from the technosphere via WWTPs to the environment within the European Union gave 1.7+/-0.34 mg annually per person. The corresponding value for decaBDE was 41+/-22 mg annually per person.

  19. Comparison of microbial communities of activated sludge and membrane biofilm in 10 full-scale membrane bioreactors.

    Science.gov (United States)

    Jo, Sung Jun; Kwon, Hyeokpil; Jeong, So-Yeon; Lee, Chung-Hak; Kim, Tae Gwan

    2016-09-15

    Operation of membrane bioreactors (MBRs) for wastewater treatment is hampered by the membrane biofouling resulting from microbial activities. However, the knowledge of the microbial ecology of both biofilm and activated sludge in MBRs has not been sufficient. In this study, we scrutinized microbial communities of biofilm and activated sludge from 10 full-scale MBR plants. Overall, Flavobacterium, Dechloromonas and Nitrospira were abundant in order of abundance in biofilm, whereas Dechloromonas, Flavobacterium and Haliscomenobacter in activated sludge. Community structure was analyzed in either biofilm or activated sludge. Among MBRs, as expected, not only diversity of microbial community but also its composition was different from one another (p  0.05). Effects of ten environmental factors on community change were investigated using Spearman correlation. MLSS, HRT, F/M ratio and SADm explained the variation of microbial composition in the biofilm, whereas only MLSS did in the activated sludge. Microbial networks were constructed with the 10 environmental factors. The network results revealed that there were different topological characteristics between the biofilm and activated sludge networks, in which each of the 4 factors had different associations with microbial nodes. These results indicated that the different microbial associations were responsible for the variation of community composition between the biofilm and activated sludge.

  20. Influence of Al³⁺ addition on the flocculation and sedimentation of activated sludge: comparison of single and multiple dosing patterns.

    Science.gov (United States)

    Wen, Yue; Zheng, Wanlin; Yang, Yundi; Cao, Asheng; Zhou, Qi

    2015-05-15

    In this study, the flocculation and sedimentation performance of activated sludge (AS) with single and multiple dosing of trivalent aluminum (Al(3+)) were studied. The AS samples were cultivated in sequencing batch reactors at 22 °C. The dosages of Al(3+) were 0.00, 0.125, 0.5, 1.0, and 1.5 meq/L for single dosing, and 0.1 meq/L for multiple dosing. Under single dosing conditions, as Al(3+) dosage increased, the zeta potential, total interaction energy, and effluent turbidity decreased, whereas the sludge volume index (SVI) increased, indicating that single Al(3+) dosing could enhance sludge flocculation, but deteriorate sedimentation. By comparison, adding an equal amount of Al(3+) through multiple dosing achieved a similar reduction in turbidity, but the zeta potential was higher, while the loosely bound extracellular polymeric substances (LB-EPS) content and SVI remarkably declined. Although the difference in the flocculation performances between the two dosing patterns was not significant, the underlying mechanisms were quite distinct: the interaction energy played a more important role under single dosing conditions, whereas multiple dosing was more effective in reducing the EPS content. Multiple dosing, which allows sufficient time for sludge restructuring and floc aggregation, could simultaneously optimize sludge flocculation and sedimentation.

  1. Correlation of wood-based components and dewatering properties of waste activated sludge from pulp and paper industry.

    Science.gov (United States)

    Kyllönen, H; Lehto, J; Pirkonen, P; Grönroos, A; Pakkanen, H; Alén, R

    2010-01-01

    Large amounts of wet sludge are produced annually in municipal and industrial wastewater treatment. Already in pulp and paper industry, more than ten million tons of primary sludge, waste activated sludge, and de-inking sludge is generated. Waste activated sludge contains large quantities of bound water, which is difficult to dewater. Low water content would be a matter of high calorific value in incineration but it also has effects on the volume and the quality of the matter to be handled in sludge disposal. In this research waste activated sludges from different pulp and paper mills were chemically characterised and dewatered. Correlations of chemical composition and dewatering properties were determined using multivariate analysis. Chemical characterisation included basic sludge analysis, elementary analysis and analysis of wood-based components, such as hemicelluloses and lignin-derived material. Dewatering properties were determined using measurements of dry solids content, flux and flocculant dosage. The effects of different variables varied according to the response concerned. The variables which were significant regarding cake DS increase in filtration or centrifugation and flocculant dosage needed in filtration were different from those which were significant regarding flux.

  2. Optimization of ozonation process for the reduction of excess sludge production from activated sludge process of sago industry wastewater using central composite design.

    Science.gov (United States)

    Subha, B; Muthukumar, M

    2012-01-01

    Sago industries effluent containing large amounts of organic content produced excess sludge which is a serious problem in wastewater treatment. In this study ozonation has been employed for the reduction of excess sludge production in activated sludge process. Central composite design is used to study the effect of ozone treatment for the reduction of excess sludge production in sago effluent and to optimise the variables such as pH, ozonation time, and retention time. ANOVA showed that the coefficient determination value (R(2)) of VSS and COD reduction were 0.9689 and 0.8838, respectively. VSS reduction (81%) was achieved at acidic pH 6.9, 12 minutes ozonation, and retention time of 10 days. COD reduction (87%) was achieved at acidic pH 6.7, 8 minutes of ozonation time, and retention time of 6 days. Low ozonation time and high retention time influence maximum sludge reduction, whereas low ozonation time with low retention time was effective for COD reduction.

  3. Bacteriophages of wastewater foaming-associated filamentous Gordonia reduce host levels in raw activated sludge

    Science.gov (United States)

    Liu, Mei; Gill, Jason J.; Young, Ry; Summer, Elizabeth J.

    2015-01-01

    Filamentous bacteria are a normal and necessary component of the activated sludge wastewater treatment process, but the overgrowth of filamentous bacteria results in foaming and bulking associated disruptions. Bacteriophages, or phages, were investigated for their potential to reduce the titer of foaming bacteria in a mixed-microbial activated sludge matrix. Foaming-associated filamentous bacteria were isolated from activated sludge of a commercial wastewater treatment plan and identified as Gordonia species by 16S rDNA sequencing. Four representative phages were isolated that target G. malaquae and two un-named Gordonia species isolates. Electron microscopy revealed the phages to be siphophages with long tails. Three of the phages - GordTnk2, Gmala1, and GordDuk1 - had very similar ~76 kb genomes, with >93% DNA identity. These genomes shared limited synteny with Rhodococcus equi phage ReqiDocB7 and Gordonia phage GTE7. In contrast, the genome of phage Gsput1 was smaller (43 kb) and was not similar enough to any known phage to be placed within an established phage type. Application of these four phages at MOIs of 5–15 significantly reduced Gordonia host levels in a wastewater sludge model by approximately 10-fold as compared to non-phage treated reactors. Phage control was observed for nine days after treatment. PMID:26349678

  4. Activated sludge characterization through microscopy: A review on quantitative image analysis and chemometric techniques

    Energy Technology Data Exchange (ETDEWEB)

    Mesquita, Daniela P. [IBB-Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, Universidade do Minho, Campus de Gualtar, 4710-057 Braga (Portugal); Amaral, A. Luís [IBB-Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, Universidade do Minho, Campus de Gualtar, 4710-057 Braga (Portugal); Instituto Politécnico de Coimbra, ISEC, DEQB, Rua Pedro Nunes, Quinta da Nora, 3030-199 Coimbra (Portugal); Ferreira, Eugénio C., E-mail: ecferreira@deb.uminho.pt [IBB-Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, Universidade do Minho, Campus de Gualtar, 4710-057 Braga (Portugal)

    2013-11-13

    Graphical abstract: -- Highlights: •Quantitative image analysis shows potential to monitor activated sludge systems. •Staining techniques increase the potential for detection of operational problems. •Chemometrics combined with quantitative image analysis is valuable for process monitoring. -- Abstract: In wastewater treatment processes, and particularly in activated sludge systems, efficiency is quite dependent on the operating conditions, and a number of problems may arise due to sludge structure and proliferation of specific microorganisms. In fact, bacterial communities and protozoa identification by microscopy inspection is already routinely employed in a considerable number of cases. Furthermore, quantitative image analysis techniques have been increasingly used throughout the years for the assessment of aggregates and filamentous bacteria properties. These procedures are able to provide an ever growing amount of data for wastewater treatment processes in which chemometric techniques can be a valuable tool. However, the determination of microbial communities’ properties remains a current challenge in spite of the great diversity of microscopy techniques applied. In this review, activated sludge characterization is discussed highlighting the aggregates structure and filamentous bacteria determination by image analysis on bright-field, phase-contrast, and fluorescence microscopy. An in-depth analysis is performed to summarize the many new findings that have been obtained, and future developments for these biological processes are further discussed.

  5. Comparison and distribution of copper oxide nanoparticles and copper ions in activated sludge reactors.

    Science.gov (United States)

    Zhang, Dongqing; Trzcinski, Antoine P; Oh, Hyun-Suk; Chew, Evelyn; Tan, Soon Keat; Ng, Wun Jern; Liu, Yu

    2017-05-12

    Copper oxide nanoparticles (CuO NPs) are being increasingly applied in the industry which results inevitably in the release of these materials into the hydrosphere. In this study, simulated waste-activated sludge experiments were conducted to investigate the effects of Copper Oxide NPs at concentrations of 0.1, 1, 10 and 50 mg/L and to compare it with its ionic counterpart (CuSO4). It was found that 0.1 mg/L of CuO NPs had negligible effects on Chemical Oxygen Demand (COD) and ammonia removal. However, the presence of 1, 10 and 50 mg/L of CuO NPs decreased COD removal from 78.7% to 77%, 52.1% and 39.2%, respectively (P copper ions were more toxic towards microorganisms compared to CuO NPs. CuO NPs were removed effectively (72-93.2%) from wastewater due to a greater biosorption capacity of CuO NPs onto activated sludge, compared to the copper ions (55.1-83.4%). The SEM images clearly showed the accumulation and adsorption of CuO NPs onto activated sludge. The decrease in Live/dead ratio after 5 h of exposure of CuO NPs and Cu(2+) indicated the loss of cell viability in sludge flocs.

  6. Bacteriophages of wastewater foaming-associated filamentous Gordonia reduce host levels in raw activated sludge.

    Science.gov (United States)

    Liu, Mei; Gill, Jason J; Young, Ry; Summer, Elizabeth J

    2015-09-09

    Filamentous bacteria are a normal and necessary component of the activated sludge wastewater treatment process, but the overgrowth of filamentous bacteria results in foaming and bulking associated disruptions. Bacteriophages, or phages, were investigated for their potential to reduce the titer of foaming bacteria in a mixed-microbial activated sludge matrix. Foaming-associated filamentous bacteria were isolated from activated sludge of a commercial wastewater treatment plan and identified as Gordonia species by 16S rDNA sequencing. Four representative phages were isolated that target G. malaquae and two un-named Gordonia species isolates. Electron microscopy revealed the phages to be siphophages with long tails. Three of the phages--GordTnk2, Gmala1, and GordDuk1--had very similar ~76 kb genomes, with >93% DNA identity. These genomes shared limited synteny with Rhodococcus equi phage ReqiDocB7 and Gordonia phage GTE7. In contrast, the genome of phage Gsput1 was smaller (43 kb) and was not similar enough to any known phage to be placed within an established phage type. Application of these four phages at MOIs of 5-15 significantly reduced Gordonia host levels in a wastewater sludge model by approximately 10-fold as compared to non-phage treated reactors. Phage control was observed for nine days after treatment.

  7. Biosorption behaviors of Cu2+,Zn2+, Cd2+ and mixture by waste activated sludge

    Institute of Scientific and Technical Information of China (English)

    LUO Sheng-lian; YUAN Lin; CHAI Li-yuan; MIN Xiao-bo; WANG Yun-yan; FANG Yan; WANG Pu

    2006-01-01

    Biosorption of heavy metal ions, such as Cu2+, Cd2+ and Zn2+, was carried out using waste activated sludge from municipal sewage treatment plant as adsorption material, and the effects of parameters, such as pH value, temperature, reaction time and sorption duration, were studied in detail. The results indicate that the removal rates of Cu2+, Zn2+ and Cd2+ with low concentration are 96.47%, 80% and 90%, respectively, adsorbed by waste activated sludge. Little effect of dosage of activated sludge on the adsorption of Cu2+ and more effects on the adsorption of Zn2+ and Cd2+ are observed. Little effect oftemperature is observed, while pH value and adsorption time exert important influence on the sorption process. The adsorption behaviors of heavy metal ions all have parabolic relationships with pH value. The optimum pH value is between 6 and 10, and the optimum adsorption time is 1 h. In single heavy metal ion system, the sorption processes of Cu2+, Zn2+ and Cd2+ are in accordance with Freundlich model, which indicates that it is suitable for the treatment of these three heavy metal ions using intermittent operation. In addition, the sorption capacity of the sludge for Cu2+ is preferential to the other two ions.

  8. Enhancement of anaerobic biohydrogen/methane production from cellulose using heat-treated activated sludge.

    Science.gov (United States)

    Lay, C H; Chang, F Y; Chu, C Y; Chen, C C; Chi, Y C; Hsieh, T T; Huang, H H; Lin, C Y

    2011-01-01

    Anaerobic digestion is an effective technology to convert cellulosic wastes to methane and hydrogen. Heat-treatment is a well known method to inhibit hydrogen-consuming bacteria in using anaerobic mixed cultures for seeding. This study aims to investigate the effects of heat-treatment temperature and time on activated sludge for fermentative hydrogen production from alpha-cellulose by response surface methodology. Hydrogen and methane production was evaluated based on the production rate and yield (the ability of converting cellulose into hydrogen and methane) with heat-treated sludge as the seed at various temperatures (60-97 degrees C) and times (20-60 min). Batch experiments were conducted at 55 degrees C and initial pH of 8.0. The results indicate that hydrogen and methane production yields peaked at 4.3 mmol H2/g cellulose and 11.6 mmol CH4/g cellulose using the seed activated sludge that was thermally treated at 60 degrees C for 40 min. These parameter values are higher than those of no-treatment seed (HY 3.6 mmol H2/g cellulose and MY 10.4 mmol CH4/g cellulose). The maximum hydrogen production rate of 26.0 mmol H2/L/d and methane production rate of 23.2 mmol CH4/L/d were obtained for the seed activated sludge that was thermally treated at 70 degrees C for 50 min and 60 degrees C for 40 min, respectively.

  9. Incorporation of inorganic material in anoxic/aerobic-activated sludge system mixed liquor.

    Science.gov (United States)

    Wentzel, M C; Ubisi, M F; Lakay, M T; Ekama, G A

    2002-12-01

    In the bioreactor of the nitrification denitrification (ND)-activated sludge system, the mixed liquor is made up of organic and inorganic materials. In the current design procedures and simulation models, the influent wastewater characteristics and biological processes that influence the bioreactor mixed liquor organic solids (as volatile suspended solids, VSS, or COD) are explicitly included. However, the mixed liquor total suspended solids (TSS, i.e. organic + inorganic solids) are calculated simply from empirical ratios of VSS/TSS. The TSS concentration is fundamental in the design of secondary settling tanks and waste activated sludge disposal. Clearly, the empirical approach to obtaining an estimate for TSS is not satisfactory within the framework of a fundamentally based model. Accordingly, the incorporation of the inorganic material present in the influent wastewater into ND-activated sludge system mixed liquor was investigated. From an experimental investigation into the distribution of inorganics in the influent, mixed liquor and effluent of a laboratory-scale ND-activated sludge system, it was concluded inter alia that (i) of the total inorganic solids in the influent, only a small fraction (2.8-7.5%) is incorporated into the mixed liquor, (ii) most of the inorganics in the influent (mean 88%) and effluent (mean 98.5%) are in the dissolved form, the balance being particulate, and (iii) the influent and effluent inorganic dissolved solids concentrations are closely equal (mean effluent to influent ratio 100%). Further, a number of models were developed to quantify the mixed liquor inorganic, and, hence, total solids. From an evaluation of these models against the experimental data, it would appear that the best approach to model the incorporation of inorganics into the activated sludge mixed liquor is to follow the concepts and principles used to develop the existing models for organic materials. With this approach, reasonably close correlation between

  10. Assembly, start and operation of an activated sludge reactor for the industrial effluents treatment: physico chemical and biological parameters

    Directory of Open Access Journals (Sweden)

    Márcia Regina Assalin

    2008-05-01

    Full Text Available Although of the immense available bibliography regarding the activated sludge process, little it is found in relation to the basic procedure to be adopted to implant, to activate and to monitor a reactor of activated sludge in laboratory scales. This article describes the assembly, departure and operation of an activated sludge system, operating in continuous process, at a laboratory scale, to study effluents treatments, using as example, Kraft E1 pulp mill effluent. Factors as biodegradability of the effluent to be treated, stationary state of the reactor, conventional operation parameters as physical chemistry and biological parameters are presented.

  11. Tank Vapor Sampling and Analysis Data Package for Tank 241-Z-361 Sampled 09/22/1999 and 09/271999 During Sludge Core Removal

    Energy Technology Data Exchange (ETDEWEB)

    VISWANATH, R.S.

    1999-12-29

    This data package presents sampling data and analytical results from the September 22 and 27, 1999, headspace vapor sampling of Hanford Site Tank 241-2-361 during sludge core removal. The Lockheed Martin Hanford Corporation (LMHC) sampling team collected the samples and Waste Management Laboratory (WML) analyzed the samples in accordance with the requirements specified in the 241-2361 Sludge Characterization Sampling and Analysis Plan, (SAP), HNF-4371, Rev. 1, (Babcock and Wilcox Hanford Corporation, 1999). Six SUMMA{trademark} canister samples were collected on each day (1 ambient field blank and 5 tank vapor samples collected when each core segment was removed). The samples were radiologically released on September 28 and October 4, 1999, and received at the laboratory on September 29 and October 6, 1999. Target analytes were not detected at concentrations greater than their notification limits as specified in the SAP. Analytical results for the target analytes and tentatively identified compounds (TICs) are presented in Section 2.2.2 starting on page 2B-7. Three compounds identified for analysis in the SAP were analyzed as TICs. The discussion of this modification is presented in Section 2.2.1.2.

  12. Tank Vapor Sampling and Analysis Data Package for Tank 241-Z-361 Sampled 09/22/1999 and 09/271999 During Sludge Core Removal

    Energy Technology Data Exchange (ETDEWEB)

    VISWANATH, R.S.

    1999-12-29

    This data package presents sampling data and analytical results from the September 22 and 27, 1999, headspace vapor sampling of Hanford Site Tank 241-2-361 during sludge core removal. The Lockheed Martin Hanford Corporation (LMHC) sampling team collected the samples and Waste Management Laboratory (WML) analyzed the samples in accordance with the requirements specified in the 241-2361 Sludge Characterization Sampling and Analysis Plan, (SAP), HNF-4371, Rev. 1, (Babcock and Wilcox Hanford Corporation, 1999). Six SUMMA{trademark} canister samples were collected on each day (1 ambient field blank and 5 tank vapor samples collected when each core segment was removed). The samples were radiologically released on September 28 and October 4, 1999, and received at the laboratory on September 29 and October 6, 1999. Target analytes were not detected at concentrations greater than their notification limits as specified in the SAP. Analytical results for the target analytes and tentatively identified compounds (TICs) are presented in Section 2.2.2 starting on page 2B-7. Three compounds identified for analysis in the SAP were analyzed as TICs. The discussion of this modification is presented in Section 2.2.1.2.

  13. Development of a sample preparation procedure of sewage sludge samples for the determination of polycyclic aromatic hydrocarbons based on selective pressurized liquid extraction.

    Science.gov (United States)

    Pena, Maria Teresa; Casais, Maria Carmen; Mejuto, Maria Carmen; Cela, Rafael

    2010-01-22

    An automated, simple and sensitive method based on selective pressurized liquid extraction (SPLE) was developed for the analysis of polycyclic aromatic hydrocarbons in sewage sludge samples. The new sample preparation procedure consists of on-line clean-up by inclusion of sorbents in the extraction cell, and combines elevated temperatures and pressures with liquid solvents to achieve fast and efficient removal of target analytes from complex sewage sludge matrices. The effects of various operational parameters (e.g. sample pretreatment, extraction solvent, temperature, pressure, static time, etc.) on the performance of SPLE procedure were carefully investigated, obtaining the best results when SPLE conditions were fixed at 140 degrees C, 1500 psi, static time of 5 min and n-hexane as extraction solvent. A new programmed temperature vaporization-gas chromatography-tandem mass spectrometry method based on large volume injection (PTV-LVI-GC-MS/MS) was also developed and analytical determinations were performed by high performance liquid chromatography coupled with fluorescence detection and GC-MS/MS. The extraction yields for the different compounds obtained by SPLE ranged from 84.8% to 106.6%. Quantification limits obtained for all of these studied compounds (between 0.0001 and 0.005 microg g(-1), dry mass) were well below the regulatory limits for all compounds considered. To test the accuracy of the SPLE technique, the optimized methodology was applied to the analysis of a certified reference material (sewage sludge (BCR088)) and a reference material (sewage sludge (RTC-CNS312-04)), with excellent results.

  14. Community Level Physiological Profiles (CLPP, Characterization and Microbial Activity of Soil Amended with Dairy Sewage Sludge

    Directory of Open Access Journals (Sweden)

    Jerzy Lipiec

    2012-03-01

    Full Text Available The aim of the present work was to assess the influence of organic amendment applications compared to mineral fertilization on soil microbial activity and functional diversity. The field experiment was set up on a soil classified as an Eutric Cambisol developed from loess (South-East Poland. Two doses of both dairy sewage sludge (20 Mg·ha−1 and 26 Mg·ha−1 and of mineral fertilizers containing the same amount of nutrients were applied. The same soil without any amendment was used as a control. The soil under undisturbed native vegetation was also included in the study as a representative background sample. The functional diversity (catabolic potential was assessed using such indices as Average Well Color Development (AWCD, Richness (R and Shannon–Weaver index (H. These indices were calculated, following the community level physiological profiling (CLPP using Biolog Eco Plates. Soil dehydrogenase and respiratory activity were also evaluated. The indices were sensitive enough to reveal changes in community level physiological profiles due to treatment effects. It was shown that dairy sewage amended soil was characterized by greater AWCD, R, H and dehydrogenase and respiratory activity as compared to control or mineral fertilized soil. Analysis of variance (ANOVA and principal component analysis (PCA were used to depict the differences of the soil bacterial functional diversity between the treatments.

  15. P-nitrophenol degradation by activated sludge attached on nonwovens.

    Science.gov (United States)

    Bhatti, Zafar Iqbal; Toda, Haruko; Furukawa, Kenji

    2002-03-01

    p-Nitrophenol (PNP) is a toxic compound that enters the environment during manufacturing and processing of a variety of industrial products. This study demonstrates the use of inexpensive and durable nonwovens as a biomass retainer for the biological degradation of p-nitrophenol. An essential aspect of p-nitrophenol degradation was the cultivation of p-nitrophenol degrading biomass prior to its attachment on the nonwovens. Results of continuous flow experiments demonstrated that using the nonwovens could attain consistent high-rate p-nitrophenol degradation. 500 mg-PNP/L was completely degraded at a hydraulic retention time of 11 h. Specific and volumetric p-nitrophenol loading rates were determined to be 165 mg-PNP/g-MLSS/d and 1.6 g-PNP/L/d, respectively. Nitrite released from p-nitrophenol breakdown was not completely nitrified to nitrate. Characteristics of p-nitrophenol degrading sludge were also investigated.

  16. Using the activated sludge model 2d (ASM2d) to understand and predict the phosphorus accumulating organisms mechanism in enhanced biological phosphorus removal in relation to disintegrated sludge as a carbon source

    OpenAIRE

    Boontian, Nittaya

    2012-01-01

    Carbon sources are considered as one of the most important factors in the performance of enhanced biological phosphorus removal (EBPR). Disintegrated sludge (DS) can act as carbon source to increase the efficiency of EBPR. This research explores the influence of DS upon phosphorus removal efficiency using mathematical simulation modeling. Activated Sludge Model No. 2d (ASM2d) is one of the most useful of activated sludge (AS) models. This is because ASM2d can express the integrated mechanisms...

  17. Microbial activities in a vertical-flow wetland system treating sewage sludge with high organic loads

    Energy Technology Data Exchange (ETDEWEB)

    Wang, R. Y.; Perissol, C.; Baldy, V.; Bonin, G.; Korboulewsky, N.

    2009-07-01

    The rhizosphere is the most active zone in treatment wetlands where take place physicochemical and biological processes between the substrate, plants, microorganisms, and contaminants. Microorganisms play the key role in the mineralisation of organic matter. substrate respiration and phosphatase activities (acid and alkaline) were chosen as indicators of microbial activities, and studied in a vertical-flow wetland system receiving sewage sludge with high organic loads under the Mediterranean climate. (Author)

  18. Detecting the nonviable and heat-tolerant bacteria in activated sludge by minimizing DNA from dead cells.

    Science.gov (United States)

    Guo, Feng; Zhang, Tong

    2014-05-01

    Propidium monoazide (PMA) has been used to determine viable microorganisms for clinical and environmental samples since selected naked DNA which was covalently cross-linked by this dye could not be PCR-amplified. In this study, we applied PMA to the activated sludge samples composed of complex bacterial populations to investigate the viability of human fecal bacteria and to determine the heat-tolerant bacteria by high-throughput sequencing of 16S ribosomal DNA (rDNA) V3 region. The methodological evaluation suggested the validity, and about 2-3 magnitude signals decreasing from the stained DNA were observed. However, the nest PCR, which was previously conducted to further minimize signals from dead cells, seemed not suitable perhaps due to the limitation of the primers. On one hand, for typical human fecal bacteria, less than half of them were viable, and most genera exhibited the similar viable percentages. It was interesting that many "unclassified bacteria" showed low viability, implying their sensitivity to environmental change. On the other hand, after heating at 60 °C for 4 h, the bacteria with high survival rate in activated sludge samples included those reported thermophiles or heat-tolerant lineages, such as Anoxybacillus and diverse species in Actinobacteria, and some novel ones, such as Gp16 subdivision in Acidobacteria. In summary, our results took a glance at the fate of fecal bacteria during sewage treatment and established an example for identifying tolerant species to lethal shocks in a complex community.

  19. Decreasing activated sludge thermal hydrolysis temperature reduces product colour, without decreasing degradability.

    Science.gov (United States)

    Dwyer, Jason; Starrenburg, Daniel; Tait, Stephan; Barr, Keith; Batstone, Damien J; Lant, Paul

    2008-11-01

    Activated sludges are becoming more difficult to degrade in anaerobic digesters, due to the implementation of stricter nitrogen limits, longer sludge ages, and removal of primary sedimentation units. Thermal hydrolysis is a popular method to enhance degradability of long-age activated sludge, and involves pressure and heat treatment of the process fluid (150-160 degrees C saturated steam). However, as documented in this study, in a full-scale system, the use of thermal hydrolysis produces coloured, recalcitrant compounds that can have downstream impacts (e.g., failure of UV disinfection, and increased effluent nitrogen). The coloured compound formed during thermal hydrolysis was found to be melanoidins. These are coloured recalcitrant compounds produced by polymerisation of low molecular weight intermediates, such as carbohydrates and amino compounds at elevated temperature (Maillard reaction). By decreasing the THP operating temperature from 165 degrees C to 140 degrees C, THP effluent colour decreased from 12,677 mg-PtCo L(-1) to 3837 mg-PtCo L(-1). The change in THP operating temperature from 165 degrees C to 140 degrees C was shown to have no significant impact on anaerobic biodegradability of the sludge. The rate and extent of COD biodegradation remained largely unaffected by the temperature change with an average first order hydrolysis rate of 0.19 d(-1) and conversion extent of 0.43 g-COD(CH4)g-COD(-1).

  20. The occurrence of intestinal parasites in swine slurry and their removal in activated sludge plants.

    Science.gov (United States)

    Reinoso, Roberto; Becares, Eloy

    2008-09-01

    Thirteen intensive pig farms and two activated sludge treatment plants for pig slurry in north-western Spain were studied from April 2005 to June 2006 in order to evaluate the presence of enteric pathogens (Cryptosporidium, Giardia and helminths) and the efficiency with which they were removed. These parasites were present on 53%, 7% and 38% of the farms studied, respectively, with concentrations of 10(4)-10(5) oocysts per litre (/L) for Cryptosporidium, 10(3)cysts/L for Giardia and 10(2)-10(3) eggs/L for helminths. The overall removal of parasites in the pig slurry treatment plants ranged from 86.7% to over 99.99%. The results revealed a constant reduction at each stage of the treatment system, with activated sludge processes being the most effective treatment in reducing pathogens in pig slurry, 78-81% for Cryptosporidium oocysts and over 99.9% for helminth eggs. A heat drying procedure for sludge removed 4.3 log units of Cryptosporidium oocysts, demonstrating the excellent effectiveness of this treatment for reducing pathogens in sludge intended to be applied to land.

  1. Effect of nonylphenol on volatile fatty acids accumulation during anaerobic fermentation of waste activated sludge.

    Science.gov (United States)

    Duan, Xu; Wang, Xiao; Xie, Jing; Feng, Leiyu; Yan, Yuanyuan; Zhou, Qi

    2016-11-15

    Most of the reported studies on anaerobic fermentation of sludge focused on the influences of operating conditions, pretreatment methods, and its characteristics, and little attention was paid to those of persistent organic pollutants (POPs) which widespreadly appeared in sludge. In this study, the effect of nonylphenol, a typical POPs in waste activated sludge (WAS), on anaerobic fermentation for volatile fatty acids (VFAs) accumulation was investigated. The concentration of VFAs during WAS anaerobic fermentation was found to be affected positively from 2856 mg COD/L in the control (without NP) to 5620 mg COD/L with NP of 200 mg/kg dry sludge. Mechanism exploration exhibited that the main reason for the enhanced VFAs accumulation in the presence of NP was that more acetic acid was generated during the acidification of WAS, which was increased by almost three times (3790 versus 1310 mg COD/L). In WAS fermentation systems, the abundance of anaerobic functional microorganisms was advantageous to the accumulation of acetic acid. Further investigation by the pure acetogen revealed that both the viability and activity of Proteiniphilum acetatigenes were improved by NP during anaerobic fermentation, resulting in more production of acetic acid and showing good agreement with that in the real WAS fermentation systems. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Characteristics of microfauna and their relationships with the performance of an activated sludge plant in China

    Institute of Scientific and Technical Information of China (English)

    ZHOU Kexin; XU Muqi; LIU Biao; CAO Hong

    2008-01-01

    The occurrence and abundance of the microfauna groups were compared with the physico-chemical and operational parameters of the Baoding Lugang Sewage Treatment Plant in China. Attached and crawling ciliates were the dominant groups of ciliates. Crawling ciliates and testate amoebae showed a strong association with effluent BOD5 (biochemical oxygen demand). Therefore, these two groups are likely to be useful bioindicators since their number decreased as the process produced poor quality effluent. Testate amoebae also had significant negative correlations with effluent TN (total nitrogen), NH4+-N, SS (suspended solids) and SVI (sludge volumetric index), which means that this group of ciliates may be indicators of good performance of the activated sludge system. Carnivorous ciliates and flagellates had significant positive correlations with SVI, suggesting that these two groups may be indicators of bad settlement conditions of sludge. As identification of the microfauna species is difficult and time-consuming, we recommend using microfauna functional groups to evaluate the performance of the activated sludge system.

  3. Biological treatment of synthetic wastewater containing 2,4 dichlorophenol (DCP) in an activated sludge unit.

    Science.gov (United States)

    Kargi, Fikret; Eker, Serkan; Uygur, Ahmet

    2005-08-01

    Chlorophenol compounds present in many chemical industry wastewaters are resistant to biological degradation because of the toxic effects of such compounds on microorganisms. Synthetic wastewater containing different concentrations of 2,4 dichlorophenol (DCP) was subjected to biological treatment in an activated sludge unit. Effects of feed DCP concentration on COD, DCP, and toxicity removals and on sludge volume index were investigated at a constant sludge age of 10 days and hydraulic residence time (HRT) of 25 h. The Resazurin method based on dehydrogenase activity was used for assessment of toxicity for the feed and effluent wastewater. Percent COD, DCP, and toxicity removals decreased and the effluent COD, DCP, and toxicity levels increased with increasing feed DCP concentrations above 150 mgl(-1) because of inhibitory effects of DCP. Biomass concentration in the aeration tank decreased and the sludge volume index (SVI) increased with feed DCP concentrations above 150 mgl(-1) resulting in lower COD and DCP removal rates. The system should be operated at feed DCP concentrations of less than 150 mgl(-1) in order to obtain high COD, DCP, and toxicity removals.

  4. Activated sludge systems removal efficiency of veterinary pharmaceuticals from slaughterhouse wastewater.

    Science.gov (United States)

    Carvalho, Pedro N; Pirra, António; Basto, M Clara P; Almeida, C Marisa R

    2013-12-01

    The knowledge on the efficiency of wastewater treatment plants (WWTPs) from animal food production industry for the removal of both hormones and antibiotics of veterinary application is still very limited. These compounds have already been reported in different environmental compartments at levels that could have potential impacts on the ecosystems. This work aimed to evaluate the role of activated sludge in the removal of commonly used veterinary drugs, enrofloxacin (ENR), tetracycline (TET), and ceftiofur, from wastewater during a conventional treatment process. For that, a series of laboratory-controlled experiments using activated sludge were carried out in batch reactors. Sludge reactors with 100 μg/L initial drug charge presented removal rates of 68 % for ENR and 77 % for TET from the aqueous phase. Results indicated that sorption to sludge and to the wastewater organic matter was responsible for a significant percentage of drugs removal. Nevertheless, these removal rates still result in considerable concentrations in the aqueous phase that will pass through the WWTP to the receiving environment. Measuring only the dissolved fraction of pharmaceuticals in the WWTP effluents may underestimate the loading and risks to the aquatic environment.

  5. Effect of Dissolved Oxygen on Microbial Population and Settling of Dairy Activated Sludge

    Directory of Open Access Journals (Sweden)

    T. Subramani

    2014-12-01

    Full Text Available The study was carried out to identify and study the settling characteristics of the dairy activated sludge. The causes and the control measure for the sludge bulking were studied. The activated sludge was generated by running a batch reactor of capacity of 10 liters for a θC of 10 days. It was operated until steady state conditions were reached. pH, DO, MLSS and COD were taken as the parameters. The settling studies were carried out for different MLSS concentrations ranging from 2g/L to 20g/L. The addition of Chlorine was selected as the control measure and was added for various doses such as 1 ml, 2 ml and 3 ml of Bleaching powder solution (1 ml of Bleaching powder solution contains 0.515 mg of Chlorine. Settling curves between interface height and time were observed before and after the addition of the Chlorine. From the settling curve the limiting solids flux were obtained. After the addition of Chlorine, there was a considerable increase in the settling velocity that improves the settling nature of the sludge. Area of Secondary settling tank was calculated from the modified solids flux method.

  6. Effectiveness of phosphate removal during anaerobic digestion of waste activated sludge by dosing iron(III).

    Science.gov (United States)

    Cheng, Xiang; Wang, Jue; Chen, Bing; Wang, Yu; Liu, Jiaqi; Liu, Lubo

    2017-05-15

    Phosphate-Fe(II) precipitation induced by Fe(III) reduction during the anaerobic digestion of excess activated sludge was investigated for the removal of phosphorus and its possible recovery. The experiments were conducted with three Fe(III) sources at 35 °C and 55 °C. The results show that ferrihydrite-Fe(III) was effectively reduced during the anaerobic sludge digestion by 63% and 96% under mesophilic and thermophilic conditions, respectively. Whereas FeCl3-Fe(III) was only mesophilically reducible and the reduction of hematite-Fe(III) was unnoticeable at either temperature. Efficient precipitation of vivianite was not observed although high saturation index values, e.g., >14 (activity reduction not considered), had been reached. This reveals the complexity of vivianite precipitation in anaerobic digestion systems; for example, Fe(II) complexation and organic interference could not be ignored. With ferrihydrite amendments at a Fe/TP of 1.5, methane production from sludge digestion was reduced by 35.1% at 35 °C, and was unaffected when the digestion temperature went up to 55 °C. But, acidic FeCl3 severely inhibited the methane production and consequently the sludge biomass degradation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Determination of artificial sweeteners in sewage sludge samples using pressurised liquid extraction and liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Ordoñez, Edgar Y; Quintana, José Benito; Rodil, Rosario; Cela, Rafael

    2013-12-13

    An analytical method for the determination of six artificial sweeteners in sewage sludge has been developed. The procedure is based on pressurised liquid extraction (PLE) with water followed by solid-phase extraction (SPE) and subsequent liquid chromatography-tandem mass spectrometry analysis. After optimisation of the different PLE parameters, extraction with aqueous 500mM formate buffer (pH 3.5) at 80°C during a single static cycle of 21min proved to be best conditions. After a subsequent SPE, quantification limits, referred to dry weight (dw) of sewage sludge, ranged from 0.3ng/g for acesulfame (ACE) to 16ng/g for saccharin (SAC) and neohespiridine dihydrochalcone. The trueness, expressed as recovery, ranged between 72% and 105% and the precision, expressed as relative standard deviation, was lower than 16%. Moreover, the method proved its linearity up to the 2μg/g range. Finally, the described method was applied to the determination of the artificial sweeteners in primary and secondary sewage sludge from urban wastewater treatment plants. Four of the six studied artificial sweeteners (ACE, cyclamate, SAC and sucralose) were found in the samples at concentrations ranging from 17 to 628ng/g dw.

  8. Influence of secondary settling tank performance on suspended solids mass balance in activated sludge systems.

    Science.gov (United States)

    Patziger, M; Kainz, H; Hunze, M; Józsa, J

    2012-05-01

    Secondary settling is the final step of the activated sludge-based biological waste water treatment. Secondary settling tanks (SSTs) are therefore an essential unit of producing a clear effluent. A further important function of SSTs is the sufficient thickening to achieve highly concentrated return sludge and biomass within the biological reactor. In addition, the storage of activated sludge is also needed in case of peak flow events (Ekama et al., 1997). Due to the importance of a high SST performance the problem has long been investigated (Larsen, 1977; Krebs, 1991; Takács et al., 1991; Ekama et al., 1997; Freimann, 1999; Patziger et al., 2005; Bürger et al., 2011), however, a lot of questions are still to solve regarding e.g. the geometrical features (inflow, outflow) and operations (return sludge control, scraper mechanism, allowable maximum values of surface overflow rates). In our study we focused on SSTs under dynamic load considering both the overall unsteady behaviour and the features around the peaks, investigating the effect of various sludge return strategies as well as the inlet geometry on SST performance. The main research tool was a FLUENT-based novel mass transport model consisting of two modules, a 2D axisymmetric SST model and a mixed reactor model of the biological reactor (BR). The model was calibrated and verified against detailed measurements of flow and concentration patterns, sludge settling, accompanied with continuous on-line measurement of in- and outflow as well as returned flow rates of total suspended solids (TSS) and water. As to the inlet arrangement a reasonable modification of the geometry could result in the suppression of the large scale flow structures of the sludge-water interface thus providing a significant improvement in the SST performance. Furthermore, a critical value of the overflow rate (q(crit)) was found at which a pronounced large scale circulation pattern develops in the vertical plane, the density current in

  9. Effect of nitrogen limitation on enrichment of activated sludge for PHA production.

    Science.gov (United States)

    Basak, Bertan; Ince, Orhan; Artan, Nazik; Yagci, Nevin; Ince, Bahar Kasapgil

    2011-10-01

    Polyhydroxyalkanoates (PHA) are good candidates to plastics because of their material properties similar to conventional plastics and complete biodegradability. The use of activated sludge can be a cheaper alternative to pure cultures for PHA production. In this study, effect of nitrogen limitation during acclimatization period of biomass on production of polyhydroxyalkanoate was investigated. Activated sludge was selected in two sequencing batch reactors operated with and without nitrogen limitation. Batch tests were performed to examine polymer productions of activated sludges acclimatized to different nitrogen regimes. Responses of biomass to different organic loading rates, organic acids, and carbon to nitrogen (C/N) ratios were studied by determining specific polymer storage rate, polymer storage yield, and sludge polymer content of biomasses. Results obtained from batch experiments showed that concentrations of polymer accumulated by two different sludges increased directly with initial substrate concentration. Observed highest polymer yields for the biomasses enriched with and without nitrogen deficiency were 0.69 g COD PHA g(-1) COD S and 0.51 g COD PHA g(-1) COD S, and corresponding polymer contents of biomasses were 43.3% (g COD PHA g(-1) COD X) and 38.3% (g COD PHA g(-1) COD X), respectively. Polymer yields for both biomasses decreased with substrate shift however, biomass enriched with nitrogen deficiency adapted well to acetate-propionate mixture. The results presented in this study showed that polymer storage ability of biomass was improved more under dynamic conditions with nitrogen deficiency when compared to that without nitrogen deficiency. Limiting ammonia availability during batch experiments also caused higher polymer production by suppressing growth, as well as during enrichment of biomass.

  10. Determination of insoluble soap in agricultural soil and sewage sludge samples by liquid chromatography with ultraviolet detection.

    Science.gov (United States)

    Cantarero, Samuel; Zafra-Gómez, Alberto; Ballesteros, Oscar; Navalón, Alberto; Vílchez, José L; Crovetto, Guillermo; Verge, Coral; de Ferrer, Juan A

    2010-11-01

    We have developed a new analytical procedure for determining insoluble Ca and Mg fatty acid salts (soaps) in agricultural soil and sewage sludge samples. The number of analytical methodologies that focus in the determination of insoluble soap salts in different environmental compartments is very limited. In this work, we propose a methodology that involves a sample clean-up step with petroleum ether to remove soluble salts and a conversion of Ca and Mg insoluble salts into soluble potassium salts using tripotassium ethylenediaminetetraacetate salt and potassium carbonate, followed by the extraction of analytes from the samples using microwave-assisted extraction with methanol. An improved esterification procedure using 2,4-dibromoacetophenone before the liquid chromatography with ultraviolet detection analysis also has been developed. The absence of matrix effect was demonstrated with two fatty acid Ca salts that are not commercial and are never detected in natural samples (C₁₃:₀ and C₁₇:₀). Therefore, it was possible to evaluate the matrix effect because both standards have similar environmental behavior (adsorption and precipitation) to commercial soaps (C₁₀:₀) to C₁₈:₀). We also studied the effect of the different variables on the clean-up, the conversion of Ca soap, and the extraction and derivatization procedures. The quantification limits found ranged from 0.4 to 0.8 mg/kg. The proposed method was satisfactorily applied for the development of a study on soap behavior in agricultural soil and sewage sludge samples.

  11. Biological activity of bleached kraft pulp mill effluents before and after activated sludge and ozone treatments.

    Science.gov (United States)

    Lopes, Alessandra Cunha; Mounteer, Ann H; Stoppa, Teynha Valverde; Aquino, Davi Santiago

    2013-01-01

    Eucalyptus bleached kraft pulp production, an important sector of the Brazilian national economy, is responsible for generating large volume, high pollutant load effluents, containing a considerable fraction of recalcitrant organic matter. The objectives of this study were to quantify the biological activity of the effluent from a eucalyptus bleached kraft pulp mill, characterize the nature of compounds responsible for biological activity and assess the effect of ozone treatment on its removal. Primary and secondary effluents were collected bimonthly over the course of one year at a Brazilian bleached eucalypt kraft pulp mill and their pollutant loads (biochemical oxygen demand (BOD), chemical oxygen demand (COD), total organic carbon (TOC), adsorbable organic halogen (AOX), lignin, extractives) and biological activity (acute and chronic toxicity and estrogenic activity) quantified. The effluent studied did not present acute toxicity to Daphnia, but presented the chronic toxicity effects of algal growth inhibition and reduced survival and reproduction in Ceriodaphnia, as well as estrogenic activity. Chronic toxicity and estrogenic activity were reduced but not eliminated during activated sludge biological treatment. The toxicity identification evaluation revealed that lipophilic organic compounds (such as residual lignin, extractives and their byproducts) were responsible for the toxicity and estrogenic activity. Ozone treatment (50 mg/L O(3)) of the secondary effluent eliminated the chronic toxicity and significantly reduced estrogen activity.

  12. Microbial Community Dynamics and Activity Link to Indigo Production from Indole in Bioaugmented Activated Sludge Systems.

    Directory of Open Access Journals (Sweden)

    Yuanyuan Qu

    Full Text Available Biosynthesis of the popular dyestuff indigo from indole has been comprehensively studied using pure cultures, but less has been done to characterize the indigo production by microbial communities. In our previous studies, a wild strain Comamonas sp. MQ was isolated from activated sludge and the recombinant Escherichia coli nagAc carrying the naphthalene dioxygenase gene (nag from strain MQ was constructed, both of which were capable of producing indigo from indole. Herein, three activated sludge systems, G1 (non-augmented control, G2 (augmented with Comamonas sp. MQ, and G3 (augmented with recombinant E. coli nagAc, were constructed to investigate indigo production. After 132-day operation, G3 produced the highest yields of indigo (99.5 ± 3.0 mg/l, followed by G2 (27.3 ± 1.3 mg/l and G1 (19.2 ± 1.2 mg/l. The microbial community dynamics and activities associated with indigo production were analyzed by Illumina Miseq sequencing of 16S rRNA gene amplicons. The inoculated strain MQ survived for at least 30 days, whereas E. coli nagAc was undetectable shortly after inoculation. Quantitative real-time PCR analysis suggested the abundance of naphthalene dioxygenase gene (nagAc from both inoculated strains was strongly correlated with indigo yields in early stages (0-30 days (P 0.10 of operation. Based on detrended correspondence analysis (DCA and dissimilarity test results, the communities underwent a noticeable shift during the operation. Among the four major genera (> 1% on average, the commonly reported indigo-producing populations Comamonas and Pseudomonas showed no positive relationship with indigo yields (P > 0.05 based on Pearson correlation test, while Alcaligenes and Aquamicrobium, rarely reported for indigo production, were positively correlated with indigo yields (P < 0.05. This study should provide new insights into our understanding of indigo bio-production by microbial communities.

  13. Enhanced high-solids anaerobic digestion of waste activated sludge by the addition of scrap iron.

    Science.gov (United States)

    Zhang, Yaobin; Feng, Yinghong; Yu, Qilin; Xu, Zibin; Quan, Xie

    2014-05-01

    Anaerobic digestion of waste activated sludge usually requires pretreatment procedure to improve the bioavailability of sludge, which involves considerable energy and high expenditures. This study proposes a cost-effective method for enhanced anaerobic digestion of sludge without a pretreatment by directly adding iron into the digester. The results showed that addition of Fe(0) powder could enhance 14.46% methane yield, and Fe scrap (clean scrap) could further enhance methane yield (improving rate 21.28%) because the scrap has better mass transfer efficiency with sludge and liquid than Fe(0) powder. The scrap of Fe with rust (rusty scrap) could induce microbial Fe(III) reduction, which resulted in achieving the highest methane yield (improving rate 29.51%), and the reduction rate of volatile suspended solids (VSS) was also highest (48.27%) among Fe powder, clean scrap and rusty scrap. PCR-DGGE proved that the addition of rusty scrap could enhance diversity of acetobacteria and enrich iron-reducing bacteria to enhance degradation of complex substrates.

  14. Methane production and microbial community structure for alkaline pretreated waste activated sludge.

    Science.gov (United States)

    Sun, Rui; Xing, Defeng; Jia, Jianna; Zhou, Aijuan; Zhang, Lu; Ren, Nanqi

    2014-10-01

    Alkaline pretreatment was studied to analyze the influence on waste activated sludge (WAS) reduction, methane production and microbial community structure during anaerobic digestion. Methane production from alkaline pretreated sludge (A-WAS) (pH = 12) increased from 251.2 mL/Ld to 362.2 mL/Ld with the methane content of 68.7% compared to raw sludge (R-WAS). Sludge reduction had been improved, and volatile suspended solids (VSS) removal rate and protein reduction had increased by ∼ 10% and ∼ 35%, respectively. The bacterial and methanogenic communities were analyzed using 454 pyrosequencing and clone libraries of 16S rRNA gene. Remarkable shifts were observed in microbial community structures after alkaline pretreatment, especially for Archaea. The dominant methanogenic population changed from Methanosaeta for R-WAS to Methanosarcina for A-WAS. In addition to the enhancement of solubilization and hydrolysis of anaerobic digestion of WAS, alkaline pretreatment showed significant impacts on the enrichment and syntrophic interactions between microbial communities.

  15. Impact of membrane solid-liquid separation on design of biological nutrient removal activated sludge systems.

    Science.gov (United States)

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

    2005-03-20

    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.

  16. Back to Basics--The Influence of DNA Extraction and Primer Choice on Phylogenetic Analysis of Activated Sludge Communities.

    Directory of Open Access Journals (Sweden)

    Mads Albertsen

    Full Text Available DNA extraction and primer choice have a large effect on the observed community structure in all microbial amplicon sequencing analyses. Although the biases are well known, no comprehensive analysis has been conducted in activated sludge communities. In this study we systematically explored the impact of a number of parameters on the observed microbial community: bead beating intensity, primer choice, extracellular DNA removal, and various PCR settings. In total, 176 samples were subjected to 16S rRNA amplicon sequencing, and selected samples were investigated through metagenomics and metatranscriptomics. Quantitative fluorescence in situ hybridization was used as a DNA extraction-independent method for qualitative comparison. In general, an effect on the observed community was found on all parameters tested, although bead beating and primer choice had the largest effect. The effect of bead beating intensity correlated with cell-wall strength as seen by a large increase in DNA from Gram-positive bacteria (up to 400%. However, significant differences were present at lower phylogenetic levels within the same phylum, suggesting that additional factors are at play. The best primer set based on in silico analysis was found to underestimate a number of important bacterial groups. For 16S rRNA gene analysis in activated sludge we recommend using the FastDNA SPIN Kit for Soil with four times the normal bead beating and V1-3 primers.

  17. Back to Basics--The Influence of DNA Extraction and Primer Choice on Phylogenetic Analysis of Activated Sludge Communities.

    Science.gov (United States)

    Albertsen, Mads; Karst, Søren M; Ziegler, Anja S; Kirkegaard, Rasmus H; Nielsen, Per H

    2015-01-01

    DNA extraction and primer choice have a large effect on the observed community structure in all microbial amplicon sequencing analyses. Although the biases are well known, no comprehensive analysis has been conducted in activated sludge communities. In this study we systematically explored the impact of a number of parameters on the observed microbial community: bead beating intensity, primer choice, extracellular DNA removal, and various PCR settings. In total, 176 samples were subjected to 16S rRNA amplicon sequencing, and selected samples were investigated through metagenomics and metatranscriptomics. Quantitative fluorescence in situ hybridization was used as a DNA extraction-independent method for qualitative comparison. In general, an effect on the observed community was found on all parameters tested, although bead beating and primer choice had the largest effect. The effect of bead beating intensity correlated with cell-wall strength as seen by a large increase in DNA from Gram-positive bacteria (up to 400%). However, significant differences were present at lower phylogenetic levels within the same phylum, suggesting that additional factors are at play. The best primer set based on in silico analysis was found to underestimate a number of important bacterial groups. For 16S rRNA gene analysis in activated sludge we recommend using the FastDNA SPIN Kit for Soil with four times the normal bead beating and V1-3 primers.

  18. Immobilized-cell-augmented activated sludge process for treating wastewater containing hazardous compounds.

    Science.gov (United States)

    Jittawattanarat, Rungrod; Kostarelos, Konstantinos; Khan, Eakalak

    2007-05-01

    A novel bioaugmentation scheme called immobilized-cell-augmented activated sludge (ICAAS) was developed. Offline enricher reactors were used to maintain immobilized acclimated cells applied to augment completely mixed activated sludge (CMAS) treating a pentachlorophenol (PCP) pulse loading. Cellulose triacetate (CA) and powder activated carbon (PAC) combined with CA (PAC + CA) were the two media types used for entrapping the PCP-degrading culture. With ICAAS at 5% by volume augmentation, PCP removal of 73.1 and 75.1% via biodegradation, volatilization, and adsorption onto suspended cells, entrapped cells, and media was achieved for the systems with CA and PAC + CA media, respectively, while PCP removal in a control CMAS, which had a comparable level of combined PCP adsorption onto suspended cells and volatilization as the ICAAS, was 48.7%. Results further showed that the immobilized cells retained their PCP-degrading ability when they were fed with the inducer (PCP) once every 20 days.

  19. Removal of Cu(II) ions by biosorption onto powdered waste sludge (PWS) prior to biological treatment in an activated sludge unit: a statistical design approach.

    Science.gov (United States)

    Pamukoglu, M Yunus; Kargi, Fikret

    2009-04-01

    Biological treatment of synthetic wastewater containing Cu(II) ions was realized in an activated sludge unit with pre-adsorption of Cu(II) onto powdered waste sludge (PWS). Box-Behnken experimental design method was used to investigate Cu(II), chemical oxygen demand (COD) and toxicity removal performance of the activated sludge unit under different operating conditions. The independent variables were the solids retention time (SRT, 5-30 d), hydraulic residence time (HRT, 5-25 h), feed Cu(II) concentration (0-50 mg L(-1)) and PWS loading rate (0-4 g h(-1)) while percent Cu(II), COD, toxicity (TOX) removals and the sludge volume index (SVI) were the objective functions. The data were correlated with a quadratic response function (R2=0.99). Cu(II), COD and toxicity removals increased with increasing PWS loading rate and SRT while decreasing with the increasing feed Cu(II) concentration and HRT. Optimum conditions resulting in maximum Cu(II), COD, toxicity removals and SVI values were found to be SRT of 30 d, HRT 15 h, PWS loading rate 3 g h(-1) and feed Cu(II) concentration of less than 30 mg L(-1).

  20. Bioremediation of oil refinery sludge by landfarming in semiarid conditions: influence on soil microbial activity.

    Science.gov (United States)

    Marin, J A; Hernandez, T; Garcia, C

    2005-06-01

    Bioremediation of a refinery sludge containing hydrocarbons in a semi-arid climate using landfarming techniques is described. The objective of this study was to assess the ability of this technique to reduce the total hydrocarbon content added to the soil with the refinery sludge in semiarid climate (low rain and high temperature). In addition, we have evaluated the effect of this technique on the microbial activity of the soil involved. For this, biological parameters (carbon fractions, microbial biomass carbon, basal respiration and ATP) and biochemical parameters(different enzymatic activities) were determined. The results showed that 80% of the hydrocarbons were eliminated in eleven months, half of this reduction taking place during the first three months. The labile carbon fractions, MBC, basal respiration and ATP of the soils submitted to landfarming showed higher values than the control soil during the first months of the process, although these values fell down by the end of the experimental period as the hydrocarbons were degraded by mineralisation. All the enzymatic activities studied: oxidoreductases such as dehydrogenase activity, and hydrolases of C(beta-glucosidase activity) and N Cycle (urease and protease) showed higher values in the soils amended with the refinery sludge than in the control. As in the case of the previous parameters, these value fell down as the bioremediation of the hydrocarbons progressed, many of them reaching levels similar to those of the control soil after eleven months.

  1. A comparison of BNR activated sludge systems with membrane and settling tank solid-liquid separation.

    Science.gov (United States)

    Ramphao, M C; Wentzel, M C; Ekama, G A; Alexander, W V

    2006-01-01

    Installing membranes for solid-liquid separation into biological nutrient removal (BNR) activated sludge (AS) systems makes a profound difference not only to the design of the membrane bio-reactor (MBR) BNR system itself, but also to the design approach for the whole wastewater treatment plant (WWTP). In multi-zone 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 inter-reactor recycle ratios. This zone mass fraction flexibility is a significant advantage of MBR BNR systems over BNR systems with secondary settling tanks (SSTs), because it allows changing the mass fractions to optimise biological N and P removal in conformity with influent wastewater characteristics and the effluent N and P concentrations required. For PWWF/ADWF ratios (fq) in the upper range (fq approximately 2.0), aerobic mass fractions in the lower range (f(maer) settling and long sludge age). However, the volume reduction compared with equivalent BNR systems with SSTs will not be large (40-60%), but the cost of the membranes can be offset against sludge thickening and stabilisation costs. Moving from a flow unbalanced raw wastewater system to a flow balanced (fq = 1) low (usually settled) wastewater strength system can double the ADWF capacity of the biological reactor, but the design approach of the WWTP changes away from extended aeration to include primary sludge stabilisation. The cost of primary sludge treatment then has to be offset against the savings of the increased WWTP capacity.

  2. Production of polyhydroxyalcanoates (PHAs) using milk whey and dairy wastewater activated sludge production of bioplastics using dairy residues.

    Science.gov (United States)

    Bosco, Francesca; Chiampo, Fulvia

    2010-04-01

    The production of polyhydroxyalcanoates (PHAs), which are biodegradable plastics, was studied using milk whey and dairy wastewater activated sludge to define a suitable C/N ratio, the pre-treatments required to reduce the protein content, and the effect of pH correction. The results show good production of PHAs at a C/N=50 and without pH correction. The use of dairy wastewater activated sludge has the advantage of not requiring aseptic conditions.

  3. Trouble Shooting and Performance Enhancement in Activated Sludge Process for Treatment of Textile Wastewaters

    Directory of Open Access Journals (Sweden)

    Mehali J. Mehta

    2014-03-01

    Full Text Available The untreated textile wastewater can cause rapid depletion of dissolved oxygen if it is directly discharged into the surface water sources due to its high Biological Oxygen Demand (BOD and Chemical Oxygen Demand(COD value. This paper focuses on various troubles in performance of activated sludge process and performance enhancement by suggesting remedial measures to ensure the proper operation of activated sludge process(ASP.Also, it is noted that modification and alternative use of chemicals such as 45% solution of sodium bisulphate in burnout printing instead of this 15% of acetic acid and 30% sodium bisulphate is mixed to improve the overall efficiency in terms of Chemical Oxygen Demand(COD and Biological Oxygen Demand(BOD.

  4. Reaction invariant-based reduction of the activated sludge model ASM1 for batch applications

    DEFF Research Database (Denmark)

    Santa Cruz, Judith A.; Mussati, Sergio F.; Scenna, Nicolás J.

    2016-01-01

    that are unaffected by the reaction progress, i.e. so-called reaction invariants. The reaction invariant concept can be used to reduce the number of ordinary differential equations (ODEs) involved in batch bioreactor models. In this paper, a systematic methodology of model reduction based on this concept is applied...... to batch activated sludge processes described by the Activated Sludge Model No. 1 (ASM1) for carbon and nitrogen removal. The objective of the model reduction is to describe the exact dynamics of the states predicted by the original model with a lower number of ODEs. This leads to a reduction...... of the numerical complexity as nonlinear ODEs are replaced by linear algebraic relationships predicting the exact dynamics of the original model....

  5. Modelling as a tool when interpreting biodegradation of micro pollutants in activated sludge systems

    DEFF Research Database (Denmark)

    Press-Kristensen, Kåre; Lindblom, Erik Ulfson; Henze, Mogens

    2007-01-01

    The aims of the present work were to improve the biodegradation of the endocrine disrupting micro pollutant, bisphenol A (BPA), used as model compound in an activated sludge system and to underline the importance of modelling the system. Previous results have shown that BPA mainly is degraded under...... aerobic conditions. Therefore the aerobic phase time in the BioDenitro process of the activated sludge system was increased from 50% to 70%. The hypothesis was that this would improve the biodegradation of BPA. Both the influent and the effluent concentrations of BPA in the experiment dropped...... probably was caused by either a larger specific biomass to influent BPA ratio, improved biodegradation related to the increased aerobic phase time, or a combination of the two. Thereby it was not possibly to determine if the increase in aerobic phase time improved the biodegradation of BPA. The work...

  6. Application of BP NN and RBF NN in Modeling Activated Sludge System

    Institute of Scientific and Technical Information of China (English)

    王维斌; 郑丕谔; 李金勇

    2003-01-01

    Based on the operation data from a certain wastewater treatment plant(WWTP) in northeast China, the models of back propagation neural network(BP NN) and radial basis function neural network(RBF NN) have been designed respectively and the ability of convergence and generalization has been analyzed separately. As for BP NN, the effects of numbers of layers and nodes have been studied; as for RBF NN, the influences of the number of nodes and the RBF′s width have been studied. It is concluded that BP NN has converged much slowly in comparison with RBF NN. The conclusion that the RBF NN is suitable for modeling activated sludge system has been drawn. An automatically optimum design program for RBF NN has been developed, through which the RBF NN model of traditional activated sludge system has been established.

  7. Modelling the fate of ciprofloxacin in activated sludge systems - The relevance of the sorption process

    DEFF Research Database (Denmark)

    Polesel, Fabio; Lehnberg, Kai; Dott, Wolfgang

    . In a previous study [1], a daily systematic reduction of ciprofloxacin removal in a full-scale WWTP (Bekkelaget, Norway) was associated to deteriorated sorption. Therefore, in this study we further investigated the sorption of ciprofloxacin onto activated sludge at laboratory- and full-scale. Targeted batch...... of ciprofloxacin in a full-scale activated sludge system. Sorption was described by linear kinetics and, in an extended version of ASM-X, using a Freundlich-based submodel. In the latter case, Freundlich parameter values estimated from the batch experiments were used for model calibration. The prediction accuracy...... was statistically evaluated in the two cases by comparing the model output with measured data. Batch experiments showed that maximum sorption capacity occurred at pH=7.4, corresponding to the isoelectric point of ciprofloxacin. A pH increase resulted in a significant reduction of sorption capacity as compared...

  8. The cold adaptability of microorganisms with different carbon source in activated sludge treating synthetical wastewater.

    Science.gov (United States)

    Niu, Chuan; Geng, Jinju; Ren, Hongqiang; Ding, Lili; Xu, Ke

    2012-11-01

    The cold adaptability of microorganisms with different carbon source under 5°C was studied in activated sludge for treating synthetical wastewater. Phospholipid fatty acid (PLFA) analysis indicated contents of unsaturated fatty acids in cell membrane at 5°C were 13.66% and 24.96% higher for glucose and sodium acetate source than that at 25°C. PLFA biomarkers showed more Gram-negative bacteria enriched than Gram-positive bacteria in low-temperature activated sludge. The Shannon-Wiener diversity analysis demonstrated glucose fed reactor in low temperature had lower PLFA diversity index (1.21-1.30) than that at 25°C and sodium acetate source was reverse (1.08-0.69). The 16S rRNA analysis manifested certain microbes were considerably suitable for existence under cold environment, most of which belong to Gram-negative bacteria.

  9. New mechanistically based model for predicting reduction of biosolids waste by ozonation of return activated sludge.

    Science.gov (United States)

    Isazadeh, Siavash; Feng, Min; Urbina Rivas, Luis Enrique; Frigon, Dominic

    2014-04-15

    Two pilot-scale activated sludge reactors were operated for 98 days to provide the necessary data to develop and validate a new mathematical model predicting the reduction of biosolids production by ozonation of the return activated sludge (RAS). Three ozone doses were tested during the study. In addition to the pilot-scale study, laboratory-scale experiments were conducted with mixed liquor suspended solids and with pure cultures to parameterize the biomass inactivation process during exposure to ozone. The experiments revealed that biomass inactivation occurred even at the lowest doses, but that it was not associated with extensive COD solubilization. For validation, the model was used to simulate the temporal dynamics of the pilot-scale operational data. Increasing the description accuracy of the inactivation process improved the precision of the model in predicting the operational data.

  10. Fish canning wastewater treatment by activated sludge: Application of factorial design optimization

    Directory of Open Access Journals (Sweden)

    Raquel O. Cristóvão

    2015-06-01

    Full Text Available The optimization of hydraulic retention time (HRT and initial organic matter concentration for dissolved organic carbon (DOC abatement of wastewater from a fish canning industry of northern Portugal by activated sludge was investigated using response surface methodology (RSM. The two parameters were chosen since it was found that the treatment efficiency is mainly influenced by them. The experimental data on DOC removal were fitted into a quadratic polynomial model using factorial design and RSM. The optimum process conditions were determined by analyzing the response surface of a three-dimensional plot and by solving the regression model equation. The obtained results showed a HRT of 6.4 h and an initial DOC of 406.2 mg/L as the best treatment conditions. Under these conditions, the maximum predicted DOC removal was 88.0%, confirming the feasibility and the reliability of fish canning wastewater treatment by activated sludge for organic content removal.

  11. A site-specific curated database for the microorganisms of activated sludge and anaerobic digesters

    DEFF Research Database (Denmark)

    McIlroy, Simon Jon; Kirkegaard, Rasmus Hansen; McIlroy, Bianca

    the composition and dynamics of the most abundant organisms. However, to understand the relationship between the population dynamics and operational parameters of the system, a functional role must be attributed to each organism. The Microbial Database for Activated Sludge (MiDAS) and Anaerobic Digesters (AD......) presented here provides a site specific curated taxonomy for abundant and important microorganisms and integrates it into a community knowledge web platform about the microbes in activated sludge (AS) and their associated ADs (www.midasfieldguide.org). The MiDAS taxonomy, a manual curation of the SILVA......, to improve the classification of unknown organisms and link these names to the wealth of present and future functional information about their ecology....

  12. Activated sludge models ASM1, ASM2, ASM2d and ASM3

    DEFF Research Database (Denmark)

    Henze, Mogens; Gujer, W.; Mino, T.;

    This book has been produced to give a total overview of the Activated Sludge Model (ASM) family at the start of 2000 and to give the reader easy access to the different models in their original versions. It thus presents ASM1, ASM2, ASM2d and ASM3 together for the first time.Modelling of activated...... sludge processes has become a common part of the design and operation of wastewater treatment plants. Today models are being used in design, control, teaching and research.ContentsASM3: Introduction, Comparison of ASM1 and ASM3, ASM3: Definition of compounds in the model, ASM3: Definition of processes...... in the Model, ASM3: Stoichiometry, ASM3: Kinetics, Limitations of ASM3, Aspects of application of ASM3, ASM3C: A Carbon based model, Conclusion ASM 2d: Introduction, Conceptual Approach, ASM 2d, Typical Wastewater Characteristics and Kinetic and Stoichiometric Constants, Limitations, Conclusion ASM 2...

  13. Efficiency Study of Nickel (II and Cadmium (II Biosorption by Powder of Waste Activated Sludge from Aqueous Solutions

    Directory of Open Access Journals (Sweden)

    A.A Ebrahimi

    2011-01-01

    Full Text Available "n "n "nBackground and Objective: Nickel (II and cadmium (II are important in environmental pollutant. Biosorption of heavy metals can be an effective process for the removal and recovery of heavy metal ions from aqueous solutions because of the decrease in sludge problems, economical issues, high efficiency and compatibility with the environment."nMaterials and Methods: power of wasted activated sludge have been contact with nickel (II and cadmium (II solutions in 0.25 and 0.75 milli molar invarious pHs and mixing pace, at 24-26 0C temperature on batch reactor system .After two hours (continuously 5-420 min in kinetic study samples were analyzed with atomic absorption spectrophotometer."nResults:The kinetic study results show that equilibrium adsorption time for nickel (II and cadmium"n(II reached within 2 hr, but the profile curve of cadmium (II biosorption was smoother than nickel (II biosorption. Both metals adsorption followed the Langmuir model and the maximum adsorption capacity (qmax for nickel (II and cadmium (II was 0.195 and 0.37 milli mole per gram respectively. The increase in pH resulted in adsorption increase for both metals. For cadmium (II at 0.25 and 0.75 mMinitial concentration there was no adsorption at pH 2 where as nickel (0.25 mM adsorption was observed at the same pH. The optimum mixing rate for both metals was 200 rpm and this effect was more obviously in greater concentration."nConclusion: Like othe biosorbents ,wasted activated sludge showed greater capacity for cadmium(II biosorption than nickel (II. Cadmium (II in modeling and biosorption characteristics study had more conformity than nickel (II.

  14. Sample preparation of sewage sludge and soil samples for the determination of polycyclic aromatic hydrocarbons based on one-pot microwave-assisted saponification and extraction.

    Science.gov (United States)

    Pena, M Teresa; Pensado, Luis; Casais, M Carmen; Mejuto, M Carmen; Cela, Rafael

    2007-04-01

    A microwave-assisted sample preparation (MASP) procedure was developed for the analysis of polycyclic aromatic hydrocarbons (PAHs) in sewage sludge and soil samples. The procedure involved the simultaneous microwave-assisted extraction of PAHs with n-hexane and the hydrolysis of samples with methanolic potassium hydroxide. Because of the complex nature of the samples, the extracts were submitted to further cleaning with silica and Florisil solid-phase extraction cartridges connected in series. Naphthalene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benz[a]anthracene, chrysene, benzo[e]pyrene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, dibenz[a,h]anthracene, benzo[g,h,i]perylene, and indeno[1,2,3-cd]pyrene, were considered in the study. Quantification limits obtained for all of these compounds (between 0.4 and 14.8 microg kg(-1) dry mass) were well below of the limits recommended in the USA and EU. Overall recovery values ranged from 60 to 100%, with most losses being due to evaporation in the solvent exchange stages of the procedure, although excellent extraction recoveries were obtained. Validation of the accuracy was carried out with BCR-088 (sewage sludge) and BCR-524 (contaminated industrial soil) reference materials.

  15. Sample preparation of sewage sludge and soil samples for the determination of polycyclic aromatic hydrocarbons based on one-pot microwave-assisted saponification and extraction

    Energy Technology Data Exchange (ETDEWEB)

    Pena, M.T.; Pensado, Luis; Casais, M.C.; Mejuto, M.C.; Cela, Rafael [Universidad de Santiago de Compostela, Dpto. Quimica Analitica, Nutricion y Bromatologia. Instituto de Investigacion y Analisis Alimentario, Santiago de Compostela (Spain)

    2007-04-15

    A microwave-assisted sample preparation (MASP) procedure was developed for the analysis of polycyclic aromatic hydrocarbons (PAHs) in sewage sludge and soil samples. The procedure involved the simultaneous microwave-assisted extraction of PAHs with n-hexane and the hydrolysis of samples with methanolic potassium hydroxide. Because of the complex nature of the samples, the extracts were submitted to further cleaning with silica and Florisil solid-phase extraction cartridges connected in series. Naphthalene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benz[a]anthracene, chrysene, benzo[e]pyrene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, dibenz[a,h]anthracene, benzo[g,h,i]perylene, and indeno[1,2,3-cd]pyrene, were considered in the study. Quantification limits obtained for all of these compounds (between 0.4 and 14.8 {mu}g kg{sup -1} dry mass) were well below of the limits recommended in the USA and EU. Overall recovery values ranged from 60 to 100%, with most losses being due to evaporation in the solvent exchange stages of the procedure, although excellent extraction recoveries were obtained. Validation of the accuracy was carried out with BCR-088 (sewage sludge) and BCR-524 (contaminated industrial soil) reference materials. (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

    Kapagiannidis, A. G.; Aivasidis, A.

    2009-07-01

    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)

  17. Fate of Malathion in an Activated Sludge Municipal Wastewater Treatment System

    Science.gov (United States)

    2013-03-01

    treatment plant ( WWTP ). There have been few studies to document the fate of these CWAs when subjected to a municipal wastewater treatment process. This...municipal activated sludge (AS) WWTP . Results show that v malathion may degrade in an AS WWTP as approximately 90% of an initial concentration of 4.25 mg...the decontamination wastewater must be disposed of as hazardous waste or possibly treated at a WWTP . There are no studies that document the fate of

  18. The Removal of Composite Reactive Dye from Dyeing Unit Effluent Using Sewage Sludge Derived Activated Carbon

    OpenAIRE

    REDDY, Sajjala SREEDHAR

    2006-01-01

    Activated carbon was prepared from dried municipal sewage sludge and batch mode adsorption experiments were conducted to study its potential to remove composite reactive dye from dyeing unit effluent. Adsorption parameters for the Langmuir and Freundlich isotherms were determined and the effects of effluent pH, adsorbent dosage, contact time and initial dye concentration were studied. The toxicity characteristic leaching protocol (TCLP) was used to assess the acceptability of sewage ...

  19. Disinfection of raw wastewater and activated sludge effluent using Fenton like reagent

    OpenAIRE

    Aslani, Hassan; Nabizadeh, Ramin; Alimohammadi, Mahmood; MESDAGHINIA, Alireza; Nadafi, Kazem; Nemati, Reza; Ghani, Maryam

    2014-01-01

    Background and objectives Water shortage problems have led to find either new water resources or improve wastewater treatment technologies in order to reuse. Due to less performance of previous units in microbial removal, disinfection has become a necessary step in wastewater treatment plants. In the present study performance of hydrogen peroxide (HP) and modified Fenton’s reagent (HP + Cu++) was considered for the disinfection of raw wastewater (RW) and activated sludge effluent (ASE). Mater...

  20. Efficiency of conventional activated sludge in the removal of linear alkylbenzene sulfonate from municipal sewage

    OpenAIRE

    2014-01-01

    Background: Linear Alkylbenzene Sulfonate (LAS) is an anionic detergent that is abundantly produced in different countries and discharged into natural environment through wastewater collection systems. Wastewater treatment systems play an important role in the removal of this contaminant. The purpose of this study was to determine the efficiency of a conventional activated sludge system in removing linear alkylbenzene sulfonate from wastewater in Kermanshah. Methods: This cross-sectional d...

  1. Enzymatic and metabolic activities of four anaerobic sludges and their impact on methane production from ensiled sorghum forage.

    Science.gov (United States)

    Sambusiti, C; Rollini, M; Ficara, E; Musatti, A; Manzoni, M; Malpei, F

    2014-03-01

    Biochemical methane potential (BMP) tests were run on ensiled sorghum forage using four inocula (urban, agricultural, mixture of agricultural and urban, granular) and differences on their metabolic and enzymatic activities were also discussed. Results indicate that no significant differences were observed in terms of BMP values (258±14NmLCH4g(-1)VS) with a slightly higher value when agricultural sludge was used as inoculum. Significant differences can be observed among different inocula, in terms of methane production rate. In particular the fastest biomethanization occurred when using the urban sludge (hydrolytic kinetic constant kh=0.146d(-1)) while the slowest one was obtained from the agricultural sludge (kh=0.049d(-1)). Interestingly, positive correlations between the overall enzymatic activities and methane production rates were observed for all sludges, showing that a high enzymatic activity may favour the hydrolysis of complex substrate and accelerate the methanization process of sorghum.

  2. Biofilms Versus Activated Sludge: Considerations in Metal and Metal Oxide Nanoparticle Removal from Wastewater.

    Science.gov (United States)

    Walden, Connie; Zhang, Wen

    2016-08-16

    The increasing application of metal and metal oxide nanoparticles [Me(O)NPs] in consumer products has led to a growth in concentration of these nanoparticles in wastewater as emerging contaminants. This may pose a threat to ecological communities (e.g., biological nutrient removal units) within treatment plants and those subject to wastewater effluents. Here, the toxicity, fate, and process implications of Me(O)NPs within wastewater treatment, specifically during activated sludge processing and biofilm systems are reviewed and compared. Research showed activated sludge achieves high removal rate of Me(O)NPs by the formation of aggregates through adsorption. However, recent literature reveals evidence that inhibition is likely for nutrient removal capabilities such as nitrification. Biofilm systems were much less studied, but show potential to resist Me(O)NP inhibition and achieve removal through possible retention by sorption. Implicating factors during bacteria-Me(O)NP interactions such as aggregation, surface functionalization, and the presence of organics are summarized. At current modeled levels, neither activated sludge nor biofilm systems can achieve complete removal of Me(O)NPs, thus allowing for long-term environmental exposure of diverse biological communities to Me(O)NPs in streams receiving wastewater effluents. Future research directions are identified throughout in order to minimize the impact of these nanoparticles released.

  3. Biodegradation of pharmaceuticals in hospital wastewater by a hybrid biofilm and activated sludge system (Hybas)

    DEFF Research Database (Denmark)

    Escola Casas, Monica; Chhetri, Ravi Kumar; Ooi, Gordon Tze Hoong;

    2015-01-01

    Hospital wastewater contributes a significant input of pharmaceuticals into municipal wastewater. The combination of suspended activated sludge and biofilm processes, as stand-alone or as hybrid process, has been suggested as a possible solution for hospital wastewater treatment. HybasTM is a hyb......Hospital wastewater contributes a significant input of pharmaceuticals into municipal wastewater. The combination of suspended activated sludge and biofilm processes, as stand-alone or as hybrid process, has been suggested as a possible solution for hospital wastewater treatment. Hybas...... of one activated sludge reactor, two HybasTM reactors and one moving bed biofilm reactor (MBBR) has been operated for 10 months, where after batch and continuous flow tests were performed for the degradation of pharmaceuticals. Removal of organic matter and nitrification mainly occurred in the first......, the measured removal rates were similar to those estimated from the batch experiments, but the concentrations of a few pharmaceuticals appeared to increase during the first treatment step. Such increase could be attributed to de-conjugation or formation from other metabolites....

  4. Evaluation of aeration energy saving in two modified activated sludge processes.

    Science.gov (United States)

    Lee, Ingyu; Lim, Honglae; Jung, Byunghun; Colosimo, Mark F; Kim, Hyunook

    2015-12-01

    A variety of modified activated sludge processes are widely used in wastewater treatment plants (WWTPs) for removing organics and nutrients (N and P). Since energy consumption in aeration basin accounts for the major part of the overall energy usage in WWTPs, efforts have been made to find ways to reduce aeration energy. In this study, two modified activated sludge processes in a pilot scale designed for nutrient removal were evaluated for the extent of energy saving: (1) ABA(2) process - adjusting air on/off period (i.e., with a temporal change); and (2) MB-A(2)O process - changing volume ratio of aerobic tank to anoxic tank (i.e., with a spatial change). For the 1st process, the air on/off period was fixed at 60min/45min with aerobic fraction being 0.57, while for the 2nd process, the aerobic/anoxic volume ratio was reduced from 0.58 to 0.42. The results demonstrate that the effluent COD, TN, NH4(+) and TP concentrations are acceptable while reduced aeration time/volume certainly saves significant energy consumption. To the best of our knowledge, this is 1st attempt to reduce the aeration period or aeration volume to save the aeration energy in these two modified activated sludge processes. The implication of these observations is further discussed.

  5. Treatment of biomass gasification wastewater using a combined wet air oxidation/activated sludge process

    Energy Technology Data Exchange (ETDEWEB)

    English, C.J.; Petty, S.E.; Sklarew, D.S.

    1983-02-01

    A lab-scale treatability study for using thermal and biological oxidation to treat a biomass gasification wastewater (BGW) having a chemical oxygen demand (COD) of 46,000 mg/l is described. Wet air oxidation (WA0) at 300/sup 0/C and 13.8 MPa (2000 psi) was used to initially treat the BGW and resulted in a COD reduction of 74%. This was followed by conventional activated sludge treatment using operating conditions typical of municipal sewage treatment plants. This resulted in an additional 95% COD removal. Overall COD reduction for the combined process was 99%. A detailed chemical analysis of the raw BGW and thermal and biological effluents was performed using gas chromatography/mass spectrometry (GC/MS). These results showed a 97% decrease in total extractable organics with WA0 and a 99.6% decrease for combined WA0 and activated sludge treatment. Components of the treated waters tended to be fewer in number and more highly oxidized. An experiment was conducted to determine the amount of COD reduction caused by volatilization during biological treatment. Unfortunately, this did not yield conclusive results. Treatment of BGW using WA0 followed by activated sludge appears to be very effective and investigations at a larger scale are recommended.

  6. A critical comparison of systematic calibration protocols for activated sludge models: a SWOT analysis.

    Science.gov (United States)

    Sin, Gürkan; Van Hulle, Stijn W H; De Pauw, Dirk J W; van Griensven, Ann; Vanrolleghem, Peter A

    2005-07-01

    Modelling activated sludge systems has gained an increasing momentum after the introduction of activated sludge models (ASMs) in 1987. Application of dynamic models for full-scale systems requires essentially a calibration of the chosen ASM to the case under study. Numerous full-scale model applications have been performed so far which were mostly based on ad hoc approaches and expert knowledge. Further, each modelling study has followed a different calibration approach: e.g. different influent wastewater characterization methods, different kinetic parameter estimation methods, different selection of parameters to be calibrated, different priorities within the calibration steps, etc. In short, there was no standard approach in performing the calibration study, which makes it difficult, if not impossible, to (1) compare different calibrations of ASMs with each other and (2) perform internal quality checks for each calibration study. To address these concerns, systematic calibration protocols have recently been proposed to bring guidance to the modeling of activated sludge systems and in particular to the calibration of full-scale models. In this contribution four existing calibration approaches (BIOMATH, HSG, STOWA and WERF) will be critically discussed using a SWOT (Strengths, Weaknesses, Opportunities, Threats) analysis. It will also be assessed in what way these approaches can be further developed in view of further improving the quality of ASM calibration. In this respect, the potential of automating some steps of the calibration procedure by use of mathematical algorithms is highlighted.

  7. Comparison of heavy metal removal efficiencies in four activated sludge processes

    Institute of Scientific and Technical Information of China (English)

    杨军; 高定; 陈同斌; 雷梅; 郑国砥; 周小勇

    2015-01-01

    The removal efficiencies of heavy metals (As, Cr, Cu, Ni, Pb and Zn) were investigated in the 17 operating municipal wastewater treatment plants (WWTPs) and compared with those in four main activated sludge processes. Significant differences of heavy metal removal efficiencies were observed among four activated sludge processes. The removal efficiency for As (75.5%) in the oxidation ditch (OD) process is significantly higher than that in the conventional activated sludge (CAS) process (38.6%) or sequencing batch reactor (SBR) process (51.4%). The mean removal efficiencies for Cu and Ni in the OD process are 90.5% and 46.7%, respectively, while low mean removal efficiencies are observed for Cu (69.9%) and Ni (16.5%), respectively, in the SBR process. The removal efficiencies for Cu and Ni in the OD process are significantly higher than those in the anaerobic-anoxic-oxic (A2-O) process. These results highlight the differences of removal efficiencies for heavy metals in different processes and should be considered when selecting a wastewater treatment process.

  8. Effects of nano-copper(II) oxide and nanomagnesium oxide particles on activated sludge.

    Science.gov (United States)

    Liu, Guoqiang; Wang, Jianmin

    2012-07-01

    Effects of nano-copper(II) oxide (nano-CuO) and nanomagnesium oxide (nano-MgO) particles on activated sludge endogenous respiration (aerobic digestion), biochemical oxygen demand (BOD) biodegradation, and nitrification were investigated through respiration rate measurement. For comparison, the effects of Cu(II) and Mg(II) ions on activated sludge were also studied. Results indicated that soluble Cu(II) has half maximum inhibitory concentration (IC50) values of 19, 5.5, 53, and 117 mg Cu/L for endogenous respiration, BOD biodegradation, ammonium oxidation, and nitrite oxidation, respectively. However, nano-CuO only inhibited BOD biodegradation at 240 mg Cu/L or more, and its associated toxicity was primarily caused by soluble Cu(II). In contrast, soluble Mg(II) was not toxic to activated sludge in the experimental concentration range, but nano-MgO inhibited BOD biodegradation and nitrification with IC50 values of 70 and 143 mg Mg/L, respectively. Further study indicated that the toxicity of nano-MgO resulted primarily from increased pH following MgO hydrolysis.

  9. Sorption and release of organics by primary, anaerobic, and aerobic activated sludge mixed with raw municipal wastewater.

    Science.gov (United States)

    Modin, Oskar; Saheb Alam, Soroush; Persson, Frank; Wilén, Britt-Marie

    2015-01-01

    New activated sludge processes that utilize sorption as a major mechanism for organics removal are being developed to maximize energy recovery from wastewater organics, or as enhanced primary treatment technologies. To model and optimize sorption-based activated sludge processes, further knowledge about sorption of organics onto sludge is needed. This study compared primary-, anaerobic-, and aerobic activated sludge as sorbents, determined sorption capacity and kinetics, and investigated some characteristics of the organics being sorbed. Batch sorption assays were carried out without aeration at a mixing velocity of 200 rpm. Only aerobic activated sludge showed net sorption of organics. Sorption of dissolved organics occurred by a near-instantaneous sorption event followed by a slower process that obeyed 1st order kinetics. Sorption of particulates also followed 1st order kinetics but there was no instantaneous sorption event; instead there was a release of particles upon mixing. The 5-min sorption capacity of activated sludge was 6.5±10.8 mg total organic carbon (TOC) per g volatile suspend solids (VSS) for particulate organics and 5.0±4.7 mgTOC/gVSS for dissolved organics. The observed instantaneous sorption appeared to be mainly due to organics larger than 20 kDa in size being sorbed, although molecules with a size of about 200 Da with strong UV absorbance at 215-230 nm were also rapidly removed.

  10. Phylogeny, physiology and distribution of 'Candidatus Microthrix calida', a new Microthrix species isolated from industrial activated sludge wastewater treatment plants.

    Science.gov (United States)

    Levantesi, Caterina; Rossetti, Simona; Thelen, Karin; Kragelund, Caroline; Krooneman, Janneke; Eikelboom, Dick; Nielsen, Per Halkjaer; Tandoi, Valter

    2006-09-01

    Twelve strains of filamentous bacteria morphologically identified as 'Microthrix parvicella' were isolated from industrial activated sludge wastewater treatment plants. 16S rRNA gene sequences analysis showed that these strains were all closely related to 'Candidatus Microthrix parvicella'. Six of them, however, had a 16S rRNA gene similarity of only 95.7% and 96.7% to 'Candidatus Microthrix parvicella' suggesting the presence of a new species. The name 'Candidatus Microthrix calida' is proposed for this new microorganism. The physiological properties of these six isolates supported the description of a new taxon. The 'Candidatus Microthrix calida' strains produced thin filaments (0.3-0.7 microm diameter), they did not grow on the media supporting the growth of 'Candidatus Microthrix parvicella' and could be cultivated at higher temperature (up to 36.5 degrees C). Preliminary data on substrate uptake were obtained by microautoradiography on pure culture. Two new fluorescence in situ hybridization (FISH) probes, Mpa-T1-1260 specific for 'Candidatus Microthrix calida' and Mpa-all-1410 targeting both Microthrix species, were designed. The presence of Microthrix spp. was investigated in 114 activated sludge plants. 'Microthrix parvicella' morphotype was detected in 23% of the analysed samples and FISH analysis revealed that 'Candidatus Microthrix calida' was present in 5% of them. The remaining 'M. parvicella' filaments were positive with probe Mpa-all-1410 but could not all be identified as 'Candidatus Microthrix parvicella' suggesting the presence of more hitherto undescribed biodiversity within this morphotype.

  11. Effect of olive mill wastewaters on the oxygen consumption by activated sludge microorganisms: an acute toxicity test method.

    Science.gov (United States)

    Paixão, S M; Anselmo, A M

    2002-01-01

    The test for inhibition of oxygen consumption by activated sludge (ISO 8192-1986 (E)) was evaluated as a tool for assessing, the acute toxicity of olive mill wastewaters (OMW). According to the ISO test, information generated by this method may be helpful in estimating the effect of a test material on bacterial communities in the aquatic environment, especially in aerobic biological treatment systems. However, the lack of standardized bioassay methodology for effluents imposed that the test conditions were modified and adapted. The experiments were conducted in the presence or absence of an easily biodegradable carbon source (glucose) with different contact times (20 min and 24 h). The results obtained showed a remarkable stimulatory effect of this effluent to the activated sludge microorganisms. In fact, the oxygen uptake rate values increase with increasing effluent concentrations and contact times up to 0.98 microl O(2) h(-1) mg(-1) dry weight for a 100% OMW sample, 24 h contact time, with blanks exhibiting an oxygen uptake rate of ca. 1/10 of this value (0.07-0.10). It seems that the application of the ISO test as an acute toxicity test for effluents should be reconsidered, with convenient adaptation for its utilization as a method of estimating the effect on bacterial communities present in aerobic biological treatment systems.

  12. Adaptive response of trivial activated sludge towards toxic effect of oNP, PCP and combination oNP/PCP

    Energy Technology Data Exchange (ETDEWEB)

    Topalova, Y.; Dimkov, R. (Sofia Univ. (Bulgaria). Faculty of Biology); Kozuharov, D. (Bulgarian Academy of Science, Sofia (Bulgaria))

    1999-01-01

    The reaction of the real aerobic activated sludge taken from the Sofia Waste Water Treatment Plant (SWWTP) and treated with the xenobiotics pentachlorphenol (PCP) (0.16 mMol), ortho-nitrophenol (oNP) (0.58 mMol) and with a combination of PCP (0.08 mMol), oNP (0.29 mMol) has been investigated in a model detoxification process. The adaptive changes are studied in the microbial structure level and at the level of changes in the qualitative and quantitative parameters of the macro-organisms in the activated sludge (consuments of 1 and 2 level). The presence of several different taxonomic groups has been shown by other researchers to be essential in the detoxification process. The quantitative changes in these taxonomic and physiological groups of micro-organisms are studied. The number of micro-organisms from Pseudomonas, Acinetobacter and the bacteria from the xenobiotic-catabolizing complex considerably increased with the individual and the combined effect of the xenobiotics oNP, PCP and oNP PCP. At the same time the toxic shock leads to a remarkable reduction of NH[sub 3] releasing, nitrifying bacteria and those from family Enterobacteriaceae. It is ascertained that the number of Ciliata, Flagellata apochromata, Oligochaeta and Rotatoria is strongly decreased in the series of samples treated with xenobiotics. The leading role of micro-organisms in the real detoxification of hazardous pollutants was experimentally confirmed by research.

  13. A methodological approach for direct quantification of the activated sludge floc size distribution by using different techniques.

    Science.gov (United States)

    Govoreanu, R; Saveyn, H; Van der Meeren, P; Nopens, I; Vanrolleghem, P A

    2009-01-01

    The activated sludge floc size distribution (FSD) is investigated by using different measurement techniques in order to gain insight in FSD assessment as well as to detect the strengths and limitations of each technique. A second objective was to determine the experimental conditions that allow a representative and accurate measurement of activated sludge floc size distributions. Laser diffraction, Time Of Transition (TOT) and Dynamic Image Analysis (DIA) devices were connected in series. The sample dilution liquid, the dilution factor and hydraulic flow conditions avoiding flocculation proved to be important. All methods had certain advantages and limitations. The MastersizerS has a broader dynamic size range and provides accurate results at high concentrations. However, it suffers from an imprecise evaluation of small size flocs and is susceptible to particle shape effects. TOT suffers less from size overestimation for non-spherical particles. However, care should be taken with the settings of the transparency check. Being primarily a counting technique, DIA suffers from a limited size detection range but is an excellent technique for process visualization. All evaluated techniques turned out to be reliable methods to quantify the floc size distribution. Selection of a certain method depends on the purpose of the measurement.

  14. Recovery and reuse of sludge from active and passive treatment of mine drainage-impacted waters: a review.

    Science.gov (United States)

    Rakotonimaro, Tsiverihasina V; Neculita, Carmen Mihaela; Bussière, Bruno; Benzaazoua, Mostafa; Zagury, Gérald J

    2017-01-01

    The treatment of mine drainage-impacted waters generates considerable amounts of sludge, which raises several concerns, such as storage and disposal, stability, and potential social and environmental impacts. To alleviate the storage and management costs, as well as to give the mine sludge a second life, recovery and reuse have recently become interesting options. In this review, different recovery and reuse options of sludge originating from active and passive treatment of mine drainage are identified and thoroughly discussed, based on available laboratory and field studies. The most valuable products presently recovered from the mine sludge are the iron oxy-hydroxides (ochre). Other by-products include metals, elemental sulfur, and calcium carbonate. Mine sludge reuse includes the removal of contaminants, such as As, P, dye, and rare earth elements. Mine sludge can also be reused as stabilizer for contaminated soil, as fertilizer in agriculture/horticulture, as substitute material in construction, as cover over tailings for acid mine drainage prevention and control, as material to sequester carbon dioxide, and in cement and pigment industries. The review also stresses out some of the current challenges and research needs. Finally, in order to move forward, studies are needed to better estimate the contribution of sludge recovery/reuse to the overall costs of mine water treatment.

  15. A novel conditioning process for enhancing dewaterability of waste activated sludge by combination of zero-valent iron and persulfate.

    Science.gov (United States)

    Zhou, Xu; Wang, Qilin; Jiang, Guangming; Liu, Peng; Yuan, Zhiguo

    2015-06-01

    Improvement of sludge dewaterability is crucial for reducing the costs of sludge disposal in wastewater treatment plants. This study presents a novel conditioning method for improving waste activated sludge dewaterability by combination of persulfate and zero-valent iron. The combination of zero-valent iron (0-30g/L) and persulfate (0-6g/L) under neutral pH substantially enhanced the sludge dewaterability due to the advanced oxidization reactions. The highest enhancement of sludge dewaterability was achieved at 4g persulfate/L and 15g zero-valent iron/L, with which the capillary suction time was reduced by over 50%. The release of soluble chemical oxygen demand during the conditioning process implied the decomposition of sludge structure and microorganisms, which facilitated the improvement of dewaterability due to the release of bound water that was included in sludge structure and microorganism. Economic analysis showed that the proposed conditioning process with persulfate and ZVI is more economically favorable for improving WAS dewaterability than classical Fenton reagent. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Hydraulic characterization of an activated sludge reactor with recycling system by tracer experiment and analytical models.

    Science.gov (United States)

    Sánchez, F; Viedma, A; Kaiser, A S

    2016-09-15

    Fluid dynamic behaviour plays an important role in wastewater treatment. An efficient treatment requires the inexistence of certain hydraulic problems such as dead zones or short-circuiting flows. Residence time distribution (RTD) analysis is an excellent technique for detecting these inefficiencies. However, many wastewater treatment installations include water or sludge recycling systems, which prevent us from carrying out a conventional tracer pulse experiment to obtain the RTD curve of the installation. This paper develops an RTD analysis of an activated sludge reactor with recycling system. A tracer experiment in the reactor is carried out. Three analytical models, derived from the conventional pulse model, are proposed to obtain the RTD curve of the reactor. An analysis of the results is made, studying which model is the most suitable for each situation. This paper is useful to analyse the hydraulic efficiency of reactors with recycling systems.

  17. Impact of septic compounds and operational conditions on the microbiology of an activated sludge system.

    Science.gov (United States)

    Pelletier, Carl; Fitzsimmons, Mary Ann; Deschênes, Sophie; Paice, Michael

    2007-01-01

    In activated sludge (AS) biotreatment, septic compounds such as volatile organic acids and reduced sulphur compounds have been frequently cited as a major cause of Thiothrix and Type 021N filamentous bulking. These filaments are common in Canadian pulp and paper biotreatment systems, where they cause settling problems in secondary clarifiers. We conducted a 14-week study of a TMP/newsprint mill effluent to characterize the septic compounds entering the biotreatment, and to determine correlations with AS biomass characteristics and biotreatment operating parameters. A significant correlation was found between the sludge volume index, the abundance of Type 021N, and the propionic acid (PA) concentration in the primary clarified effluent. PA also induced a significant change in the flocculating bacteria size distribution determined by digital imaging. Consequently, the correlation observed between PA and Type 021N bulking is an indirect effect of inhibition of floc-forming microorganisms, giving a competitive advantage to filaments.

  18. Eikelboom's morphotype 0803 in activated sludge belongs to the genus Caldilinea in the phylum Chloroflexi.

    Science.gov (United States)

    Kragelund, Caroline; Thomsen, Trine Rolighed; Mielczarek, Artur Tomasz; Nielsen, Per Halkjaer

    2011-06-01

    Micromanipulated filamentous bacteria from bulking and foaming activated sludge morphologically identified as Eikelboom type 0803 were shown to be affiliated to the genus Caldilinea within the phylum Chloroflexi. Specific FISH probes were designed for their in situ detection and quantification in seven Danish wastewater treatment plants with biological nutrient removal. The survey applied all species-specific probes for Chloroflexi of relevance in activated sludge treatment plants as well as the phylum-specific probes. Type 0803 filaments constituted around 20% of the total Chloroflexi population. In four of the treatment plants, type 0803 and type 0092 co-occurred and were the dominating fraction of the Chloroflexi population. In the other plants, most Chloroflexi could not be identified beyond the phylum level, suggesting a yet far larger diversity. On average, for all plants, the total Chloroflexi population constituted 12% of the entire microbial population and seems to play an important structural role in the sludge floc formation. Ecophysiological characterization of type 0803 showed their potential role in macromolecule conversion as evident by high levels of exoenzyme expression. Acetate was not consumed. Glucose was consumed with oxygen, nitrite and nitrite as electron acceptors, suggesting that type 0803 may be a denitrifier. Their surfaces were hydrophobic, explaining their occasional occurrence in foaming incidents.

  19. Detailed spatio-temporal solids concentration profiling during batch settling of activated sludge using a radiotracer.

    Science.gov (United States)

    De Clercq, Jeriffa; Jacobs, Filip; Kinnear, David J; Nopens, Ingmar; Dierckx, Rudi A; Defrancq, Jacques; Vanrolleghem, Peter A

    2005-05-01

    In building and tuning good settling models for secondary clarifiers of wastewater treatment plants, there is a need for measured continuous solids concentration profiles during batch settling. Conventional measuring techniques have difficulties in recording this kind of data, either because they are invasive, or because of the low solids concentration and/or solids density of activated sludge. This paper investigates a novel non-invasive measurement technique borrowed from nuclear medicine, using a solids radiotracer and gamma cameras, to obtain solids concentration profiles during the batch settling of activated sludge, in a pilot-scale column with a height of 1m. The technique does not disturb the settling process, does not alter the settling characteristics, gives profiles every minute and every few millimeters, and is capable of measuring in a range of 0-25 g/l with high accuracy. Dynamic solids concentration profile measurements were performed for sludges of different wastewater treatment plants, and at different initial concentrations. The results show a quantitative representation of the settling process, and reveal hindered and compression settling.

  20. Toxicity of Aqueous Fullerene nC60 to Activated Sludge: Nitrification Inhibition and Microtox Test

    Directory of Open Access Journals (Sweden)

    Yongkui Yang

    2012-01-01

    Full Text Available The increasing production and use of fullerene nanomaterials raised their exposure potential to the activated sludge during biological wastewater treatment process. In this study, the toxicity of aqueous nanoscaled C60 (nC60 to activated sludge was investigated using nitrification inhibition and Microtox test. The test solutions of nC60 were prepared using two methods: long stirring (Stir/nC60 and toluene exchange (Tol/nC60. The nC60 aggregation in test medium was also evaluated for toxicity assessment. The results showed that the nC60 aggregation behaved differently in two test mediums during the incubation periods. The nC60 toxicity was greatly influenced by the preparation method. Stir/nC60 presented no significant toxicity to both the nitrification sludge and bioluminescent bacteria at the maximum concentration studied. In contrast, the EC20 of Tol/nC60 was obtained to be 4.89 mg/L (3 h for the nitrification inhibition and 3.44 mg/L (30 min for Microtox test, respectively.

  1. Back to Basics – The Influence of DNA Extraction and Primer Choice on Phylogenetic Analysis of Activated Sludge Communities

    DEFF Research Database (Denmark)

    Albertsen, Mads; Karst, Søren Michael; Ziegler, Anja Sloth

    2015-01-01

    DNA extraction and primer choice have a large effect on the observed community structure in allmicrobial amplicon sequencing analyses. Although the biases are well known, no com- prehensive analysis has been conducted in activated sludge communities. In this study we systematically explored...... the impact of a number of parameters on the observed microbial community: bead beating intensity, primer choice, extracellular DNA removal, and various PCR settings. In total, 176 samples were subjected to 16S rRNA amplicon sequencing, and selected samples were investigated throughmetagenomics...... and metatranscriptomics. Quantitative fluorescence in situ hybridization was used as a DNA extraction-independent method for qualitative comparison. In general, an effect on the observed community was found on all parameters tested, although bead beating and primer choice had the largest effect. The effect of bead...

  2. Response of aerobic granular sludge to the long-term presence to nanosilver in sequencing batch reactors: reactor performance, sludge property, microbial activity and community.

    Science.gov (United States)

    Quan, Xiangchun; Cen, Yan; Lu, Fang; Gu, Lingyun; Ma, Jingyun

    2015-02-15

    The increasing use of silver nanoparticles (Ag NPs) raises concerns about their potential toxic effects on the environment. Granular shape sludge is a special type of microbial aggregate. The response of aerobic granular sludge (AGS) to the long-term presence of Ag NPs has not been well studied. In this study, AGS was exposed to 5 and 50mg/L Ag NPs in sequence batch reactors (SBRs) for 69 days, and its response was evaluated based on the sludge properties, microbial activity and community, and reactor performance. The results showed that Ag NPs caused inhibition to microbial activities of AGS from Day 35. At the end of 69 days of Ag NPs exposure, the microbial activity of AGS was significantly inhibited in terms of inhibitions of the ammonia oxidizing rate (33.0%), respiration rate (17.7% and 45.6%) and denitrification rate (6.8%), as well as decreases in the ammonia mono-oxygenase and nitrate reductase activities. During the long-term exposure, the AGS maintained its granular shape and large granule size (approximately 900 μm); the microbial community of AGS slightly changed, but the dominant microbial population remained. Overall, the AGS tolerated the toxicity of Ag NPs well, but a long-term exposure may produce chronic toxicity to the AGS, which is concerning.

  3. Principles and potential of the anaerobic digestion of waste-activated sludge

    Energy Technology Data Exchange (ETDEWEB)

    Appels, Lise; Degreve, Jan [Department of Chemical Engineering, Katholieke Universiteit Leuven, W. De Croylaan 46, B-3001 Heverlee (Belgium); Baeyens, Jan [Department of Chemical Engineering, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom); Dewil, Raf [Department of Chemical Engineering, Katholieke Universiteit Leuven, W. De Croylaan 46, B-3001 Heverlee (Belgium); Department of Chemical Engineering, Associated Faculty of Technology and Biosciences, Campus De Nayer, Katholieke Universiteit Leuven, Jan De Nayerlaan 5, B-2860 Sint-Katelijne-Waver (Belgium)

    2008-12-15

    When treating municipal wastewater, the disposal of sludge is a problem of growing importance, representing up to 50% of the current operating costs of a wastewater treatment plant. Although different disposal routes are possible, anaerobic digestion plays an important role for its abilities to further transform organic matter into biogas (60-70 vol% of methane, CH{sub 4}), as thereby it also reduces the amount of final sludge solids for disposal whilst destroying most of the pathogens present in the sludge and limiting odour problems associated with residual putrescible matter. Anaerobic digestion thus optimises WWTP costs, its environmental footprint and is considered a major and essential part of a modern WWTP. The potential of using the biogas as energy source has long been widely recognised and current techniques are being developed to upgrade quality and to enhance energy use. The present paper extensively reviews the principles of anaerobic digestion, the process parameters and their interaction, the design methods, the biogas utilisation, the possible problems and potential pro-active cures, and the recent developments to reduce the impact of the problems. After having reviewed the basic principles and techniques of the anaerobic digestion process, modelling concepts will be assessed to delineate the dominant parameters. Hydrolysis is recognised as rate-limiting step in the complex digestion process. The microbiology of anaerobic digestion is complex and delicate, involving several bacterial groups, each of them having their own optimum working conditions. As will be shown, these groups are sensitive to and possibly inhibited by several process parameters such as pH, alkalinity, concentration of free ammonia, hydrogen, sodium, potassium, heavy metals, volatile fatty acids and others. To accelerate the digestion and enhance the production of biogas, various pre-treatments can be used to improve the rate-limiting hydrolysis. These treatments include

  4. Compression dewatering of municipal activated sludge: effects of salt and pH.

    Science.gov (United States)

    Raynaud, Mickael; Vaxelaire, Jean; Olivier, Jérémy; Dieudé-Fauvel, Emilie; Baudez, Jean-Christophe

    2012-09-15

    Even after mechanical dewatering, activated sludge contains a large amount of water. Due to its composition and biological nature this material is usually highly compressible and known to be difficult to dewater. In the present work, two treatments (salt addition and pH modification) are proposed to highlight some aspects which could explain the poor dewaterability of activated sludge. Dewatering tests are carried out in a pressure-driven device in order to well examine both, filtration and compression stages. Physico-chemical parameters, such as surface charge, hydrophobicity, extracellular polymeric substances (EPS) content and filtrate turbidity are measured on the tested sludge, for a better analysis of dewatering results. The dewatering ability of the sludge is widely linked to the cohesion of the flocculated matrix and the presence of fine particles. Both treatments alter the flocculated matrix and release fine particles. The release of fine particles tends to clog both, the filter cake and the filter medium. Consequently, the filtration rate decreases due to higher resistances to the flow. On another hand, the polymeric matrix breakdown enables to release some water trapped within the floc to the bulk liquid phase and thus facilitates its removal, which tends to decrease the moisture content of the filter-cake. It also impacts the compression dewatering step. The more destroyed structures lead to less elastic cakes and thus a slower primary consolidation stage. At the opposite, the mobility of the broken aggregates within the filter-cake does not seem to be improved by size reduction (the kinetics of the secondary consolidation stage are not significantly modified).

  5. Effect of wet oxidation on the fingerprints of polymeric substances from an activated sludge.

    Science.gov (United States)

    Urrea, José Luis; Collado, Sergio; Oulego, Paula; Díaz, Mario

    2016-11-15

    Thermal pre-treatments of activated sludge involve the release of a high amount of polymeric substances into the bulk medium. The molecular size of these polymers will largely define the subsequent biological treatment of the liquid effluent generated. In this work, the effects of wet oxidation treatment (WO) on the fingerprints of the polymeric substances which compose the activated sludge, were analysed. For a better understanding of these transformations, the sludge was separated into its main fractions: soluble microbial products (SMP), loosely bound extracellular polymeric substances (LB-EPS), tightly bound extracellular polymeric substances (TB-EPS) and naked cells, and then each one was subjected to WO separately (190 °C and 65 bar), determining the fingerprints evolution by size exclusion technique. Results revealed a fast degradation of larger molecules (over 500 kDa) during the first minutes of treatment (40 min). WO also increases the absorptive properties of proteins (especially for 30 kDa), which is possibly due to the hydroxylation of phenylalanine amino acids in their structure. WO of naked cells involved the formation of molecules between 23 and 190 kDa, which are related to the release of cytoplasmic polymers, and more hydrophobic polymers, probably from the cell membrane. The results allowed to establish a relationship between the location of polymeric material and its facility to become oxidised; thus, the more internal the polymeric material in the cell, the easier its oxidation. When working directly with the raw sludge, hydrolysis mechanisms played a key role during the starting period. Once a high degree of solubilisation was reached, the molecules were rapidly oxidised into other compounds with refractory characteristics. The final effluent after WO showed almost 90% of low molecular weight solubilised substances (0-35 kDa).

  6. Removal of phenol by activated carbons prepared from palm oil mill effluent sludge

    Institute of Scientific and Technical Information of China (English)

    Md. Zahangir ALAM; Suleyman A. MUYIBI; Mariatul F.MANSOR; Radziah WAHID

    2006-01-01

    The study was attempted to produce activated carbons from palm oil mill effluent (POME) sludge. The adsorption capacity of the activated carbons produced was evaluated in aqueous solution of phenol. Two types of activation were followed, namely,thermal activation at 300, 500 and 800℃, and physical activation at 150℃ (boiling treatment). A control (raw POME sludge) was used to compare the adsorption capacity of the activated carbons produced. The results indicated that the activation temperature of 800℃showed maximum absorption capacity by the activated carbon (POME 800) in aqueous solution of phenol. Batch adsorption studies showed an equilibrium time of 6 h for the activated carbon of POME 800. It was observed that the adsorption capacity was higher at lower values of pH (2-3) and higher value of initial concentration of phenol (200-300 mg/L). The equilibrium data were fitted by the Langmuir and Freundlich adsorption isotherms. The adsorption of phenol onto the activated carbon POME 800 was studied in terms of pseudo- first and second order kinetics to predict the rate constant and equilibrium capacity with the effect of initial phenol concentrations. The rate of adsorption was found to be better correlation for the pseudo-second order kinetics compared to the first order kinetics.

  7. Simultaneous addition of zero-valent iron and activated carbon on enhanced mesophilic anaerobic digestion of waste-activated sludge.

    Science.gov (United States)

    Wang, Tongyu; Qin, Yujie; Cao, Yan; Han, Bin; Ren, Junyi

    2017-08-11

    The performance of biogas generation and sludge degradation was studied under different zero-valent iron/activated carbon (ZVI/AC) ratios in detail in mesophilic anaerobic digestion of sludge. A good enhancement of methane production was obtained at the 10:1 ZVI/AC ratio, and the cumulative methane production was 132.1 mL/g VS, 37.6% higher than the blank. The methane content at the 10:1 ZVI/AC ratio reached 68.8%, which was higher than the blank (55.2%) and the sludge-added AC alone (59.6%). For sludge degradation, the removal efficiencies of total chemical oxygen demand (TCOD), proteins, and polysaccharides were all the highest at the 10:1 ZVI/AC ratio. The concentration of available phosphorus (AP) decreased after anaerobic digestion process. On the other hand, the concentrations of available nitrogen (AN) and available potassium (AK) increased after the anaerobic digestion process and showed a gradually decreasing trend with increasing ZVI/AC ratio. The concentrations of AN and AK were 2303.1-4200.3 and 274.7-388.3 mg/kg, showing a potential for land utilization.

  8. Optimal policies for activated sludge treatment systems with multi effluent stream generation

    Directory of Open Access Journals (Sweden)

    Gouveia R.

    2000-01-01

    Full Text Available Most industrial processes generate liquid waste, which requires treatment prior to disposal. These processes are divided into sectors that generate effluents with time dependent characteristics. Each sector sends the effluent to wastewater treatment plants through pumping-stations. In general, activated sludge is the most suitable treatment and consists of equalization, aeration and settling tanks. During the treatment, there is an increase in the mass of microorganisms, which needs to be removed. Sludge removal represents the major operating costs for wastewater treatment plants. The objective of this work is to propose an optimization model to minimize sludge generation using a superstructure in which the streams from pumping-stations can be sent to the equalization tank. In addition, the aeration tank is divided into cells that can be fed in series and parallel. The model relies on mass balances, kinetic equations, and the resulting Nonlinear Programming problem generates the best operational strategy for the system feed streams with a high substrate removal. Reductions of up to 30 % can be achieved with the proposed strategy maintened BOD efficiency removal upper than 98 %.

  9. Influence of flocculation and settling properties of activated sludge in relation to secondary settler performance.

    Science.gov (United States)

    Wilén, B M; Onuki, M; Hermansson, M; Lumley, D; Mino, T

    2006-01-01

    Floc characteristics were studied at a full scale activated sludge treatment plant with a unique process solution incorporating pre-denitrification with post-nitrification in nitrifying trickling filters. Since greater nitrogen removal is achieved when more secondary settled wastewater is recirculated to the trickling filters, the secondary settlers are always operated close to their maximal capacity. The flocculation and settling properties are therefore crucial and have an effect on the overall plant performance. Since the plant is operated at a short sludge age, these properties change quickly, resulting in variable maximal secondary settler capacity. The dynamics in floc structure and microbial community composition were studied and correlated to the secondary settler performance. Fluorescence in situ hybridisation was used to investigate the microbial community structure and their spatial distribution. The floc structure could to some extent be related to the flocculation and settling properties of the sludge. Even small differences had an influence suggesting that colloidal properties also play a significant role in determining the floc properties. No correlation between microbial community composition and settling properties could be established with the group-specific probes investigated.

  10. Full activated sludge model no. 1 calibration experience at a medium-size WWTP in Mexico.

    Science.gov (United States)

    Fall, C; Loaiza-Navia, J; Esparza-Soto, M

    2009-01-01

    As part of the efforts done to introduce the practice of modeling in Latin America, this research carried out at the North-East WWTP of Monterrey represents the first comprehensive modeling case in Mexico. The main objective was to reproduce the organic carbon removal and sludge production rates of the plant, based on ASM1. Different intermediate studies were performed prior to the calibration of the model: influent characterization, tracer tests and hydraulics modeling, sludge settling tests and respirometry. Two fractionation methods (STOWA protocol and Influent-advisor) were compared, showing no equivalent patterns. A stepwise sequence of calibration was developed and successfully applied. The hydraulics of the reactors at the plant was reproduced by use of a series of 3 to 5 CSTRs. The waste and return activated sludge flowrates (Q(WAS) and Q(RAS)) were corrected based on the inorganic and total suspended solids mass balances. The Vesilind settling constants were measured (V(o) and r(hind)), while the flocculent zone settling parameter (r(floc)) was adjusted to calibrate the secondary clarifier. In ASM1, the adjusted parameters were the COD soluble inert fraction (frS(I)) and the particulate substrate fraction (FrX(S)). All other ASM1 parameters were kept at their default values. The steady-state calibrated model (in GPS-X) adequately described the quality of the effluent (carbon and nitrogen) as well as the sludge composition (M. Liquor and WAS). This case study provides voluntarily detailed data to allow its wide use for training and teaching purposes.

  11. Preparation of sludge-based activated carbon and its application in dye wastewater treatment.

    Science.gov (United States)

    Wang, Xiaoning; Zhu, Nanwen; Yin, Bingkui

    2008-05-01

    A novel activation process was adopted to produce highly porous activated carbon from cyclic activated sludge in secondary precipitator in municipal wastewater treatment plant for dye removal from colored wastewater. The physical properties of activated carbon produced with the activation of 3M KOH solution in the atmosphere of steam were investigated. Adsorption removal of a dye, Acid Brilliant Scarlet GR, from aqueous solution onto the sludge-based activated carbon was studied under varying conditions of adsorption time, initial concentration, carbon dosage and pH. Adsorption equilibrium was obtained in 15 min for the dye initial concentration of 300 mg/L. Initial pH of solution had an insignificant impact on the dye removal. Results indicated that 99.7% coloration and 99.6% total organic carbon (TOC) were removed after 15 min adsorption in the synthetic solution of Acid Brilliant Scarlet GR with initial concentration of 300 mg/L of the dye and 20 g/L activated carbon. The Langmuir and Freundlich equilibrium isotherm models fitted the adsorption data well with R(2)=0.996 and 0.912, respectively. Accordingly, it is concluded that the procedure of developing activated carbon used in this study could be effective and practical for utilizing in dye wastewater treatment.

  12. Filtration and Leach Testing for REDOX Sludge and S-Saltcake Actual Waste Sample Composites

    Energy Technology Data Exchange (ETDEWEB)

    Shimskey, Rick W.; Billing, Justin M.; Buck, Edgar C.; Daniel, Richard C.; Draper, Kathryn E.; Edwards, Matthew K.; Geeting, John GH; Hallen, Richard T.; Jenson, Evan D.; Kozelisky, Anne E.; MacFarlan, Paul J.; Peterson, Reid A.; Snow, Lanee A.; Swoboda, Robert G.

    2009-02-20

    A testing program evaluating actual tank waste was developed in response to Task 4 from the M-12 External Flowsheet Review Team (EFRT) issue response plan.( ) The test program was subdivided into logical increments. The bulk water-insoluble solid wastes that are anticipated to be delivered to the Waste Treatment and Immobilization Plant (WTP) were identified according to type such that the actual waste testing could be targeted to the relevant categories. Under test plan TP-RPP-WTP-467, eight broad waste groupings were defined. Samples available from the 222S archive were identified and obtained for testing. Under this test plan, a waste-testing program was implemented that included: • Homogenizing the archive samples by group as defined in the test plan • Characterizing the homogenized sample groups • Performing parametric leaching testing on each group for compounds of interest • Performing bench-top filtration/leaching tests in the hot cell for each group to simulate filtration and leaching activities if they occurred in the UFP2 vessel of the WTP Pretreatment Facility. This report focuses on filtration/leaching tests performed on two of the eight waste composite samples and follow-on parametric tests to support aluminum leaching results from those tests.

  13. Chemically coupled microwave and ultrasonic pre-hydrolysis of pulp and paper mill waste-activated sludge: effect on sludge solubilisation and anaerobic digestion.

    Science.gov (United States)

    Tyagi, Vinay Kumar; Lo, Shang-Lien; Rajpal, Ankur

    2014-05-01

    The effects of alkali-enhanced microwave (MW; 50-175 °C) and ultrasonic (US) (0.75 W/mL, 15-60 min) pretreatments, on solubilisation and subsequent anaerobic digestion efficiency of pulp and paper mill waste-activated sludge, were investigated. Improvements in total chemical oxygen demand and volatile suspended solids (VSS) solubilisation were limited to 33 and 39 % in MW pretreatment only (175 °C). It reached 78 and 66 % in combined MW-alkali pretreatment (pH 12 + 175 °C), respectively. Similarly, chemical oxygen demand and VSS solubilisation were 58 and 37 % in US pretreatment alone (60 min) and it improved by 66 and 49 % after US-alkali pretreatment (pH 12 + 60 min), respectively. The biogas yield for US 60 min-alkali (pH 12)-pretreated sludge was significantly improved by 47 and 20 % over the control and US 60 reactors, respectively. The biogas generation for MW (150 °C)-alkali (pH 12)-pretreated sludge was only 6.3 % higher than control; however, it was 8.3 % lower than the MW (150 °C) reactor, which was due to the inhibition of anaerobic activity under harsh thermal-alkali treatment condition.

  14. METHANOL REMOVAL FROM METHANOL-WATER MIXTURE USING ACTIVATED SLUDGE, AIR STRIPPING AND ADSORPTION PROCESS: COMPARATIVE STUDY

    Directory of Open Access Journals (Sweden)

    SALAM K. AL-DAWERY

    2015-12-01

    Full Text Available An experimental research has been carried out in order to examine the removal of methanol from methanol-water mixtures using three different methods; activated sludge; activated carbon and air stripping. The results showed that the methanol was totally consumed by the bacteria as quickly as the feed entered the activated sludge vessel. Air stripping process has a limited ability for removing of methanol due to strong intermolecular forces between methanol and water; however, the results showed that the percentage of methanol removed using air pressure at 0.5 bar was higher than that of using air pressure of 0.25 bar. Removal of methanol from the mixture with a methanol content of 5% using activated carbon was not successful due to the limited capacity of the of the activated carbon. Thus, the activated sludge process can be considered as the most suitable process for the treatment of methanol-water mixtures.

  15. Startup of the Anammox Process in a Membrane Bioreactor (AnMBR) from Conventional Activated Sludge.

    Science.gov (United States)

    Gutwiński, P; Cema, G; Ziembińska-Buczyńska, A; Surmacz-Górska, J; Osadnik, M

    2016-12-01

      In this study, a laboratory-scale anammox process in a membrane bioreactor (AnMBR) was used to startup the anaerobic ammonium oxidation (anammox) process from conventional activated sludge. Stable operation was achieved after 125 days. From that time, nitrogen load was gradually increased. After six months, the average nitrogen removal efficiency exceeded 80%. The highest obtained special anammox activity (SAA) achieved was 0.17 g (-N + -N) (g VSS × d)-1. Fluorescent in situ hybridization also proved the presence of the anammox bacteria, typically a genus of Brocadia anammoxidans and Kuenenia stuttgartiensis.

  16. The fate of linear alcohol ethoxylates during activated sludge sewage treatment.

    Science.gov (United States)

    Battersby, N S; Sherren, A J; Bumpus, R N; Eagle, R; Molade, I K

    2001-10-01

    Model continuous activated sludge (CAS) plants (Husmann units) were used to study the fate of two commercial, alcohol ethoxylate (AE) surfactants during aerobic sewage treatment. The surfactants were produced by the ethoxylation of an essentially linear C(12-15) alcohol (NEODOL 25) with an average of 7 (C(12-15)EO7) or 3 (C(12-15)EO3) moles of ethylene oxide (EO). Recent analytical developments made it possible to measure levels of AE that included the free alcohol and EO1 oligomers across the CAS system, from the influent feed, on the activated sludge, through to the effluent. Measured concentrations of AE (as C(12-15)EO(0-20)) in the synthetic sewage feeds to the test CAS plants lay in the range 11-13 mg/l. During stable operation at 20 degrees C, an average of 5 microg/l AE were present in the C(12-15)EO7 CAS plant effluent, giving a removal (bioelimination) of >99.9%. When levels of AE on the sludge, and polyethylene glycols (PEGs--an expected biodegradation intermediate) in the effluent and on the sludge were also taken into account, biodegradation was considered to be responsible for >98.7% of the observed removal. During operation at a winter temperature (10 degrees C), an average of 26 microg/l AE were present in the C(12-15)EO7 CAS plant effluent, giving a removal of 99.8%. Biodegradation was estimated to be responsible for >97.2% of the observed removal. During operation at 20 degrees C, an average of 7 microg/l AE were present in the C(12-15)EO3 CAS plant effluent, giving a removal of >99.9%. No analysis for PEG was performed in this case but the low level of AE on the sludge (0.2 mg/g dry solids) suggested that biodegradation was responsible for most of the observed removal. Neither surfactant had any adverse effect on the sewage treatment efficiencies of the CAS plants in terms of dissolved organic carbon (DOC) removal, nitrification or biomass levels.

  17. Evaluation of the Isolated Bacteria from Activated Sludge of Asalouyeh Special Zone Municipal Wastewater Treatment for Bioaugmentation of Kerosene-Contaminated Soils

    Directory of Open Access Journals (Sweden)

    F Kafilzadeh

    2016-09-01

    Full Text Available Background and Objectives: Bioaugmentation is a superior technique in bioremediation of contaminated soils with petroleum hydrocarbons. The aim of this study was to evaluate the effect of isolated bacteria from activated sludge of Asalouyeh special zone municipal wastewater treatment for bioaugmentation of kerosene-contaminated soils and to study the growth of isolated bacteria in the presence of different concentrations of this product. Materials and Methods: Sampling of activated sludge was carried out from two treatment plants in Asalouyeh zone. Isolation of degrading bacteria was performed by culturing the samples on basal mineral medium. Emulsification test and evaluating the kinetic growth of bacteria were carried out in different concentrations of kerosene. Isolated bacteria were inoculated to polluted soils with kerosene oil compound for bioaugmentation and measuring their bioremediation potentials and the rate of biodegradation were measured by InfraRed (IR spectroscopy. Results: In this study, three bacterias: Pseudomonas putida, Serratia marcescens, and Proteus mirabilis were isolated and identified as kerosene degrading bacterias from activated sludge. P. putida was recognized as the most powerful degrading bacterium of this oil product according to the emulsification tests, measuring the growth of bacteria in various concentrations of kerosene, the results of bioaugmentation of contaminated column of soil with kerosene, and reducing the level of Total Petroleum Hydrocarbons (TPHs. This bacterium with emulsification rate of 3.8 could reduce 71.03% of TPHs within 30 days.    Conclusion: According to the adaption of Pseudomonas putida, Serratia marcescens, and Proteus mirabilis in activated sludge with variety of pollutants in sewage, they can be used as non-indigenous bacteria for bioaugmentation and cleaning up the soil contaminated petroleum hydrocarbons.

  18. Addition of polyaluminiumchloride (PACl) to waste activated sludge to mitigate the negative effects of its sticky phase in dewatering-drying operations.

    Science.gov (United States)

    Peeters, Bart; Dewil, Raf; Vernimmen, Luc; Van den Bogaert, Benno; Smets, Ilse Y

    2013-07-01

    This paper presents a new application of polyaluminiumchloride (PACl) as a conditioner for waste activated sludge prior its dewatering and drying. It is demonstrated at lab scale with a shear test-based protocol that a dose ranging from 50 to 150 g PACl/kg MLSS (mixed liquor suspended solids) mitigates the stickiness of partially dried sludge with a dry solids content between 25 and 60 %DS (dry solids). E.g., at a solids dryness of 46% DS the shear stress required to have the pre-consolidated sludge slip over a steel surface is reduced with 35%. The salient feature of PACl is further supported by torque data from a full scale decanter centrifuge used to dewater waste sludge. The maximal torque developed by the screw conveyor inside the decanter centrifuge is substantially reduced with 20% in the case the sludge feed is conditioned with PACl. The beneficial effect of waste sludge conditioning with PACl is proposed to be the result of the bound water associated with the aluminium polymers in PACl solutions which act as a type of lubrication for the intrinsically sticky sludge solids during the course of drying. It can be anticipated that PACl addition to waste sludge will become a technically feasible and very effective method to avoid worldwide fouling problems in direct sludge dryers, and to reduce torque issues in indirect sludge dryers as well as in sludge decanter centrifuges.

  19. Degradation of malathion by Pseudomonas during activated sludge treatment system using principal component analysis (PCA)

    Institute of Scientific and Technical Information of China (English)

    Hashmi Imran; Khan M Altaf; Kim Jong-Guk

    2006-01-01

    Popular descriptive multivariate statistical method currently employed is the principal component analyses (PCA) method.PCA is used to develop linear combinations that successively maximize the total variance of a sample where there is no known group structure. This study aimed at demonstrating the performance evaluation of pilot activated sludge treatment system by inoculating a strain of Pseudomonas capable of degrading malathion which was isolated by enrichment technique. An intensive analytical program was followed for evaluating the efficiency of biosimulator by maintaining the dissolved oxygen (DO) concentration at 4.0 mg/L.Analyses by high performance liquid chromatographic technique revealed that 90% of malathion removal was achieved within 29 h of treatment whereas COD got reduced considerably during the treatment process and mean removal efficiency was found to be 78%.The mean pH values increased gradually during the treatment process ranging from 7.36-8.54. Similarly the mean ammonia-nitrogen (NH3-N) values were found to be fluctuating between 19.425-28.488 mg/L, mean nitrite-nitrogen (NO3-N) ranging between 1.301-2.940 mg/L and mean nitrate-nitrogen (NO3-N) ranging between 0.0071-0.0711 mg/L. The study revealed that inoculation of bacterial culture under laboratory conditions could be used in bioremediation of environmental pollution caused by xenobiotics. The PCA analyses showed that pH, COD, organic load and total malathion concentration were highly correlated and emerged as the variables controlling the first component, whereas dissolved oxygen, NO3-N and NH3-N govemed the second component. The third component repeated the trend exhibited by the first two components.

  20. Rethinking growth and decay kinetics in activated sludge - towards a new adaptive kinetics approach.

    Science.gov (United States)

    Friedrich, Michael; Jimenez, Jose; Pruden, Amy; Miller, Jennifer H; Metch, Jacob; Takács, Imre

    2017-02-01

    Growth kinetics in activated sludge modelling (ASM) are typically assumed to be the result of intrinsic growth and decay properties and thus process parameters are deemed to be constant. The activity change in a microbial population is expressed in terms of variance of the active biomass fraction and not actual shifts in bacterial cellular activities. This approach is limited, in that it does not recognise the reality that active biomass is highly physiologically adaptive. Here, a strong correlation between maximum specific growth rate (μmax) and decay rate (be) of ordinary heterotrophic organisms was revealed in both low solids retention times (SRT) and high SRT activated sludge systems. This relationship is indicative of physiological adaptation either for growth (high μmax and be) or survival optimization (low μmax and be). Further, the nitrifier decay process was investigated using molecular techniques to measure decay rates of ammonia oxidizing bacteria and nitrite oxidizing bacteria over a range of temperatures. This approach revealed decay rates 10-12% lower than values previously accepted and used in ASM. These findings highlight potential benefits of incorporating physiological adaptation of heterotrophic and nitrifying populations in future ASM.

  1. Waste activated sludge treatment based on temperature staged and biologically phased anaerobic digestion system.

    Science.gov (United States)

    Yu, Jingwen; Zheng, Mingxia; Tao, Tao; Zuo, Jiane; Wang, Kaijun

    2013-10-01

    The concept of temperature staged and biological phased (TSBP) was proposed to enhance the performance of waste-activated sludge anaerobic digestion. Semi-continuous experiments were used to investigate the effect of temperature (35 to 70 degrees C) as well as the hydraulic retention time (HRT) (2, 4 and 6 days) on the acidogenic phase. The results showed that the solubilization degree of waste-activated sludge increased from 14.7% to 30.1% with temperature increasing from 35 to 70 degrees C, while the acidification degree was highest at 45 degrees C (17.6%), and this was quite different from the temperature impact on hydrolysis. Compared with HRT of 2 and 6 days, 4 days was chosen as the appropriate HRT because of its relatively high solubilization degree (24.6%) and acidification degree (20.1%) at 45 degrees C. The TSBP system combined the acidogenic reactor (45 degrees C, 4 days) with the methanogenic reactor (35 degrees C, 16 days) and the results showed 84.8% and 11.4% higher methane yield and volatile solid reduction, respectively, compared with that of the single-stage anaerobic digestion system with HRT of 20 days at 35 degrees C. Moreover, different microbial morphologies were observed in the acidogenic- and methanogenic-phase reactors, which resulted from the temperature control and HRT adjustment. All the above results indicated that 45 degrees C was the optimum temperature to inhibit the activity of methanogenic bacteria in the acidogenic phase, and temperature staging and phase separation was thus accomplished. The advantages of the TSBP process were also confirmed by a full-scale waste-activated sludge anaerobic digestion project which was an energy self-sufficient system.

  2. Power Analysis for Real-Time PCR Quantification of Genes in Activated Sludge and Analysis of the Variability Introduced by DNA Extraction

    Science.gov (United States)

    Dionisi, Hebe M.; Harms, Gerda; Layton, Alice C.; Gregory, Igrid R.; Parker, Jack; Hawkins, Shawn A.; Robinson, Kevin G.; Sayler, Gary S.

    2003-01-01

    The aims of this study were to determine the power of discrimination of the real-time PCR assay for monitoring fluctuations in microbial populations within activated sludge and to identify sample processing points where methodological changes are needed to minimize the variability in target quantification. DNA was extracted using a commercially available kit from mixed liquor samples taken from the aeration tank of four bench-scale activated-sludge reactors operating at 2-, 5-, 10-, and 20-day solid retention times, with mixed-liquor volatile suspended solid (MLVSS) values ranging from 260 to 2,610 mg/liter. Real-time PCR assays for bacterial and Nitrospira 16S rRNA genes were chosen because they represent, respectively, a highly abundant and a less-abundant bacterial target subject to clustering within the activated sludge matrix. The mean coefficient of variation in DNA yields (measured as microgram of DNA per milligram of MLVSS) in triplicate extractions of 12 different samples was 12.2%. Based on power analyses, the variability associated with DNA extraction had a small impact on the overall variability of the real-time PCR assay. Instead, a larger variability was associated with the PCR assay. The less-abundant target (Nitrospira 16S rRNA gene) had more variability than the highly abundant target (bacterial 16S rRNA gene), and samples from the lower-biomass reactors had more variability than samples from the higher-biomass reactors. Power analysis of real-time PCR assays indicated that three to five samples were necessary to detect a twofold increase in bacterial 16S rRNA genes, whereas three to five samples were required to detect a fivefold increase in Nitrospira 16S rRNA genes. PMID:14602618

  3. Back to basics – the influence of DNA extraction and primer choice on phylogenetic analysis in activated sludge communities

    DEFF Research Database (Denmark)

    Albertsen, Mads; Karst, Søren Michael; Ziegler, Anja Sloth

    DNA extraction and primer choice have a large effect on the observed community structure in all phylogenetic analyses. Although the biases are well known, no comprehensive analysis have been conducted in activated sludge communities. In this study we investigated the effect of bead beating...... intensity and primer choice on the observed community using 16S rDNA amplicon sequencing. Quantitative fluorescence in situ hybridization (qFISH) was used as a DNA extraction independent method to evaluate the results. The bead beating intensity correlated with cell-wall strength and showed...... that the manufacture recommended settings were insufficient to retrieve a large part of the community. In addition, the in silico “best” primer set was found to greatly underestimate a number of important phyla when compared to qFISH results. The findings underline the need for sample specific and DNA extraction...

  4. Thermo-alkaline pretreatment of waste activated sludge at low-temperatures: effects on sludge disintegration, methane production, and methanogen community structure.

    Science.gov (United States)

    Kim, Jaai; Yu, Youngseob; Lee, Changsoo

    2013-09-01

    Low-temperature thermo-alkaline pretreatment of waste activated sludge (WAS) was studied, within the region of 0-0.2 M NaOH and 60-90°C, for the effects of NaOH concentration and temperature on sludge degradability in anaerobic digestion (AD). Significant disintegration of sludge solids (up to 75.6%) and an increase in methane production (up to 70.6%) were observed in the pretreatment trials. Two quadratic models were successfully generated by response surface analysis (R(2)>0.9, pmethane production (MP) respond to changes in the pretreatment conditions. The maximum responses of SD (77.8%) and MP (73.9% increase over the control) were shown at [0.16 M NaOH, 90°C] and [0.10 M NaOH, 73.7°C], respectively. NaOH addition showed a significant influence on the evolution of methanogen community structure during AD, whereas temperature did not. Aceticlastic Methanosaeta and Methanosarcina speceies were likely the major methanogens.

  5. ATP as an indicator of biomass activity in thermophilic upflow anaerobic sludge blanket reactor

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    This work investigated the biomass activity in a thermophilic upflow anaerobic sludge blanket (UASB) reactor of wastewater treatment. Synthetic textile wastewater with pH 10-11, COD level of 2000-3000 mg/L was tested. Cellular adenosine triphosphate (ATP) in volatile solids (VS; mg ATP/gVS) was measured and expressed as specific ATP content to compare the biomass activity in up zone and lower zone in UASB reactor. The result shows that the specific ATP content based on total volatile solids (VS)in lower zone (0. 046 mgATP/gVS average) is much lower than that in up zone (0.62 mgATP/gVS average) due to high content of inactive biomass and high pH in lower zone. The SATP in up zone increases as HRT increases and approaches to a maximum value of 0.85 mgATP/gVS at HRT of 7h, then decreases. It shows most of the total VS in up zone represent active bacterial biomass at HRT of 7h. Rate of subtract utilization is directly related to the activity of microorganisms in the reactor. The effect of HRT on SATP in lower zone is not as significant as on SATP in up zone. The buffer capacity of the thermophilic UASB reactor is very good. It is the activity of sludge granules in lower zone that give the UASB reactor such a good buffer capacity to the inlet high pH.

  6. Occurrence of fungi degrading aromatic hydrocarbons in activated sludge biocenoses

    Directory of Open Access Journals (Sweden)

    Anna Grabińska-Łoniewska

    2014-08-01

    Full Text Available A set of 21 strains of yeast-like microorganisms isolated from biocenoses of aerobic and anaerobic wastewater treatment systems were assayed for their ability to utilize aromatic hydrocarbons as a sole C-source. Basing on the achieved results, the highly biochemically active strains for application in enhancing of wastewaters and exhaust gases purification as well as soil bioremediation were selected.

  7. Long-term effects of cupric oxide nanoparticles (CuO NPs) on the performance, microbial community and enzymatic activity of activated sludge in a sequencing batch reactor.

    Science.gov (United States)

    Wang, Sen; Li, Zhiwei; Gao, Mengchun; She, Zonglian; Ma, Bingrui; Guo, Liang; Zheng, Dong; Zhao, Yangguo; Jin, Chunji; Wang, Xuejiao; Gao, Feng

    2017-02-01

    The long-term effects of cupric oxide nanoparticles (CuO NPs) on the performance, microbial activity and microbial community of activated sludge were investigated in a sequencing batch reactor (SBR). The SBR performance had no evident change at 0-10 mg/L CuO NPs, whereas the CuO NPs concentration at 30-60 mg/L affected the COD, NH4(+)-N and soluble orthophosphate (SOP) removal, nitrogen and phosphorus removal rate and microbial enzymatic activity of activated sludge. Some CuO NPs might be absorbed on the surface of activated sludge or penetrate the microbial cytomembrane into the microbial cell interior of activated sludge. Compared to 0 mg/L CuO NPs, the reactive oxygen species (ROS) production and lactate dehydrogenase (LDH) release increased by 43.6% and 56.4% at 60 mg/L CuO NPs, respectively. The variations of ROS production and LDH release demonstrated that CuO NPs could induce the toxicity towards the microorganisms and destroy the integrity of microbial cytomembrane in the activated sludge. High throughput sequencing of 16S rDNA indicated that CuO NPs could evidently impact on the microbial richness, diversity and composition of activated sludge in the SBR.

  8. Activated sludge morphology characterization through an image analysis procedure

    Directory of Open Access Journals (Sweden)

    Y. G. Perez

    2006-09-01

    Full Text Available This work deals with the development of a digital image analysis procedure to characterize microbial flocs obtained in three different WWTP: a bench-scale Sequencing Batch Reactor (SBR dealing with phenol and nitrogen biological removal, a municipal treatment unit (Ilha do Governador, Rio de Janeiro, Brazil and an industrial wastewater treatment plant (Ciba - Estrada do Colégio, Rio de Janeiro, Brazil. The developed procedure permits to obtain its morphological parameters like equivalent diameter, compactness, roundness and porosity properties as well as the fractal dimension. This procedure was validated and lead to identify the major relationships between the analysed morphological parameters. A minimum of 300 flocs should be included in the image analysis and a significant influence of the sample dilution step on the mean size of the flocs was verified. The porosity parameter positively correlated with the fractal dimension of microbial aggregates indicating the that highly porous flocs are very irregular.

  9. Occurrence, fate and ecotoxicological assessment of pharmaceutically active compounds in wastewater and sludge from wastewater treatment plants in Chongqing, the Three Gorges Reservoir Area

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Qing, E-mail: qyan2005@hotmail.com [Key Laboratory of the Three Gorges Reservoir Region' s Eco-Environments of Ministry of Education, Chongqing University, Chongqing 400045 (China); College of Geography Science and Tourism, Chongqing Normal University, Chongqing 400047 (China); Gao, Xu, E-mail: gaoxu@cqu.edu.cn [Key Laboratory of the Three Gorges Reservoir Region' s Eco-Environments of Ministry of Education, Chongqing University, Chongqing 400045 (China); Chen, You-Peng [Key Laboratory of the Three Gorges Reservoir Region' s Eco-Environments of Ministry of Education, Chongqing University, Chongqing 400045 (China); Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 401122 (China); Peng, Xu-Ya; Zhang, Yi-Xin; Gan, Xiu-Mei; Zi, Cheng-Fang [Key Laboratory of the Three Gorges Reservoir Region' s Eco-Environments of Ministry of Education, Chongqing University, Chongqing 400045 (China); Guo, Jin-Song [Key Laboratory of the Three Gorges Reservoir Region' s Eco-Environments of Ministry of Education, Chongqing University, Chongqing 400045 (China); Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 401122 (China)

    2014-02-01

    The occurrence, removal and ecotoxicological assessment of 21 pharmaceutically active compounds (PhACs) including antibiotics, analgesics, antiepileptics, antilipidemics and antihypersensitives, were studied at four municipal wastewater treatment plants (WWTP) in Chongqing, the Three Gorges Reservoir Area. Individual treatment unit effluents, as well as primary and secondary sludge, were sampled and analyzed for the selected PhACs to evaluate their biodegradation, persistence and partitioning behaviors. PhACs were identified and quantified using high performance liquid chromatography/tandem mass spectrometry after solid-phase extraction. All the 21 analyzed PhACs were detected in wastewater and the target PhACs except acetaminophen, ibuprofen and gemfibrozil, were also found in sludge. The concentrations of the antibiotics and SVT were comparable to or even higher than those reported in developed countries, while the case of other target PhACs was opposite. The elimination of PhACs except acetaminophen was incomplete and a wide range of elimination efficiencies during the treatment were observed, i.e. from “negative removal” to 99.5%. The removal of PhACs was insignificant in primary and disinfection processes, and was mainly achieved during the biological treatment. Based on the mass balance analysis, biodegradation is believed to be the primary removal mechanism, whereas only about 1.5% of the total mass load of the target PhACs was removed by sorption. Experimentally estimated distribution coefficients (< 500 L/kg, with a few exceptions) also indicate that biodegradation/transformation was responsible for the removal of the target PhACs. Ecotoxicological assessment indicated that the environment concentrations of single compounds (including sulfadiazine, sulfamethoxazole, ofloxacin, azithromycin and erythromycin-H{sub 2}O) in effluent and sludge, as well as the mixture of the 21 detected PhACs in effluent, sludge and receiving water had a significant

  10. Biodegradation of pharmaceuticals in hospital wastewater by a hybrid biofilm and activated sludge system (Hybas).

    Science.gov (United States)

    Escolà Casas, Mònica; Chhetri, Ravi Kumar; Ooi, Gordon; Hansen, Kamilla M S; Litty, Klaus; Christensson, Magnus; Kragelund, Caroline; Andersen, Henrik R; Bester, Kai

    2015-10-15

    Hospital wastewater contributes a significant input of pharmaceuticals into municipal wastewater. The combination of suspended activated sludge and biofilm processes, as stand-alone or as hybrid process (hybrid biofilm and activated sludge system (Hybas™)) has been suggested as a possible solution for hospital wastewater treatment. To investigate the potential of such a hybrid system for the removal of pharmaceuticals in hospital wastewater a pilot plant consisting of a series of one activated sludge reactor, two Hybas™ reactors and one moving bed biofilm reactor (MBBR) has been established and adapted during 10 months of continuous operation. After this adaption phase batch and continuous experiments were performed for the determination of degradation of pharmaceuticals. Removal of organic matter and nitrification mainly occurred in the first reactor. Most pharmaceuticals were removed significantly. The removal of pharmaceuticals (including X-ray contrast media, β-blockers, analgesics and antibiotics) was fitted to a single first-order kinetics degradation function, giving degradation rate constants from 0 to 1.49 h(-1), from 0 to 7.78 × 10(-1)h(-1), from 0 to 7.86 × 10(-1)h(-1) and from 0 to 1.07 × 10(-1)h(-1) for first, second, third and fourth reactors respectively. Generally, the highest removal rate constants were found in the first and third reactors while the lowest were found in the second one. When the removal rate constants were normalized to biomass amount, the last reactor (biofilm only) appeared to have the most effective biomass in respect to removing pharmaceuticals. In the batch experiment, out of 26 compounds, 16 were assessed to degrade more than 20% of the respective pharmaceutical within the Hybas™ train. In the continuous flow experiments, the measured removals were similar to those estimated from the batch experiments, but the concentrations of a few pharmaceuticals appeared to increase during the first treatment step. Such increase

  11. Biosorption of copper (II) ions from synthetic aqueous solutions by drying bed activated sludge

    Energy Technology Data Exchange (ETDEWEB)

    Benaissa, H., E-mail: ho_benaissa@yahoo.fr [Laboratory of Sorbent Materials and Water Treatment, Department of Chemistry, Faculty of Sciences, University of Tlemcen, P.O. Box 119, 13000 Tlemcen (Algeria); Elouchdi, M.A. [Laboratory of Sorbent Materials and Water Treatment, Department of Chemistry, Faculty of Sciences, University of Tlemcen, P.O. Box 119, 13000 Tlemcen (Algeria)

    2011-10-30

    Highlights: {yields} Dried activated sludge has been investigated for the removal of copper ions from aqueous synthetic solutions, in batch conditions. {yields} Copper uptake was time contact, initial copper concentration, initial pH solution and copper salt type dependent. {yields} Maximum copper uptake obtained was q{sub m} = 62.50 mg/g (0.556 mmol/g) under the investigated experimental conditions. - Abstract: In the present work, the usefulness of dried activated sludge has been investigated for the removal of copper ions from synthetic aqueous solutions. Kinetic data and equilibrium sorption isotherm were measured in batch conditions. The influence of some parameters such as: contact time, initial copper concentration, initial pH of solution and copper salt nature on copper biosorption kinetics has been studied. Copper uptake was time contact, initial copper concentration, initial pH solution and copper salt type dependent. Maximum copper sorption was found to occur at initial pH 5. Two simplified kinetic models including a first-order rate equation and a pseudo second-order rate equation were selected to describe the biosorption kinetics. The process followed a pseudo second-order rate kinetics. The process mechanism was found to be complex, consisting of external mass transfer and intraparticle mass transfer diffusion. Copper biosorption process was particle-diffusion-controlled, with some predominance of some external mass transfer at the initial stages for the different experimental parameters studied. Langmuir and Freundlich models were used to describe sorption equilibrium data at natural pH of solution. Results indicated that the Langmuir model gave a better fit to the experimental data than the Freundlich model. Maximum copper uptake obtained was q{sub m} = 62.50 mg/g (0.556 mmol/g) under the investigated experimental conditions. Scanning electron microscopy coupled with X-ray energy dispersed analysis for copper-equilibrated dried activated sludge

  12. Treatment of azo dye Acid Orange 52 using ozonation and completed-mixed activated sludge process

    Science.gov (United States)

    Abidin, C. Z. A.; Fahmi; Ong, S. A.; Ahmad, R.; Sabri, S. N.

    2017-06-01

    In this study, the characteristic of colour and COD removal of azo dye Acid Orange 52 (AO52) by ozonation, in combination with complete-mixed activated sludge process (CMAS) was evaluated. The experimentation was arranged in two phases: during the first one, only ozonation was performed, while, during the second phase, it was integrated with CMAS. The performance of colour and COD concentration of AO52 with and without CMAS treatment, is compared and evaluated. From the results, it is obvious that high decolourization from the start of CMAS was contributed from the pre-treatments. The colour removal was due to the fact that ozonation able to cleave the azo bonds that represent colour. Thus, CMAS without pre-treatment are unable to decolourize the dyes sufficiently. 59.6% COD was removed from the first-stage, while merely 9.8% COD fraction removed from the subsequence second-stage CMAS. It is suggested that the rapid COD removal without ozonation are due to activated sludge adsorption processes. The decreased of mixed liquor suspended solids (MLSS) affected the CMAS performances, as the biomass decreased due to lack of nutrient for activated sludge microorganisms to multiply. Results from pre-ozonation alone contributed more than 50% of total COD removal, which indicated that at higher ozone dosage, tend to mineralize azo dye. Thus, ozonation not oxidized the dye though complete mineralization that produce carbon dioxide and water. However, it is a potential process for enhancing colour removal and biodegradability of dye-containing wastewater, once the appropriate ozonation time is determined. Therefore, the role of ozonation seems to break down the dye molecules and created ozonation by-product that is easily biodegraded in the subsequent biological treatment.

  13. Estimation of Viable Biomass In Wastewater And Activated Sludge By Determination of ATP, Oxygen Utilization Rate And FDA Hydrolysis

    DEFF Research Database (Denmark)

    Jørgensen, Poul-Erik; Eriksen, T.; Jensen, B.K.

    1992-01-01

    by inoculating a nutrient medium with either wastewater or activated sludge. Biomass was then determined directly by measurement of dry weight of growth culture (dw), and compared to data obtained by using the previously mentioned methods. In the exponential growth phase, ATP content showed the best correlation......ATP content, oxygen utilization rate (OUR) and fluorescein diacetate (FDA) hydrolysis were tested for the ability to express the amount of viable biomass in wastewater and activated sludge. The relationship between biomass and these activity parameters was established in growth cultures made...... plants, it was found that ATP content and respiration rate estimated viable biomass to range from 81 to 293 mg dw/g SS for raw wastewater and from 67 to 187 mg dw/g SS for activated sludge with a rather weak correlation between ATP and respiration measurements. The FDA hydrolysis estimated viable biomass...

  14. Sorption and biodegradation of artificial sweeteners in activated sludge processes.

    Science.gov (United States)

    Tran, Ngoc Han; Gan, Jie; Nguyen, Viet Tung; Chen, Huiting; You, Luhua; Duarah, Ankur; Zhang, Lifeng; Gin, Karina Yew-Hoong

    2015-12-01

    There is limited information on the occurrence and removal of artificial sweeteners (ASs) in biological wastewater treatment plants, and in particular, the contribution of sorption and biodegradation to their removal. This study investigated the fate of ASs in both the aqueous and solid phases in a water reclamation plant (WRP). All the four targeted ASs, i.e. acesulfame (ACE), sucralose (SUC), cyclamate (CYC) and saccharine (SAC), were detected in both the aqueous and solid phases of raw influent and primary effluent samples. The concentrations of CYC and SAC in secondary effluent or MBR permeate were below their method detection limits. ACE and SUC were persistent throughout the WRP, whereas CYC and SAC were completely removed in biological treatment (>99%). Experimental results showed that sorption played a minor role in the elimination of the ASs due to the relatively low sorption coefficients (Kd), where Kd<500L/kg. In particular, the poor removal of ACE and SUC in the WRP may be attributed to their physiochemical properties (i.e. logKow<0 or logD<3.2) and chemical structures containing strong withdrawing electron functional groups in heterocyclic rings (i.e. chloride and sulfonate).

  15. Important limitations in the modeling of activated sludge : biased calibration of the hydrolysis process

    DEFF Research Database (Denmark)

    Insel, G.; Gul, Ö.K.; Orhon, D.

    2002-01-01

    ), provides the majority of the required experimental database. However, currently used procedures still involve a number of basic and practical problems. Model evaluation of the OUR data may generate a distorted image of the processes involved. Hydrolysis is the most important, yet the most vulnerable...... process as far as the experimental assessment of accurate kinetic parameters is concerned. This study intends to provide an overview of major experimental limitations in the modeling of activated sludge, with emphasis on the appropriate experimental design for the assessment of the hydrolysis rate....

  16. Evaluation of the persistence of micropollutants through pure-oxygen activated sludge nitrification and denitrification

    Science.gov (United States)

    Levine, A.D.; Meyer, M.T.; Kish, G.

    2006-01-01

    The persistence of pharmaceuticals, hormones, and household and industrial chemicals through a pure-oxygen activated sludge, nitrification, denitrification wastewater treatment facility was evaluated. Of the 125 micropollutants that were tested in this study, 55 compounds were detected in the untreated wastewater, and 27 compounds were detected in the disinfected effluent. The persistent compounds included surfactants, fire-retardant chemicals, pesticides, fragrance compounds, hormones, and one pharmaceutical. Physical-chemical properties of micropollutants that affected partitioning onto wastewater solids included vapor pressure and octanol-water partition coefficients.

  17. 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)

    1999-06-01

    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.

  18. Stoichiometric deduction of activated sludge process for organic carbon and nitrogen removal

    Institute of Scientific and Technical Information of China (English)

    LIU Jian-yong; ZOU Lian-pei

    2009-01-01

    The activated sludge process (ASP) is the most generally applied biological wastewater treatment method. The ASP for the removal of organic carbon and nitrogen can be looked as the combination of eight processes. In order to set up an ASP model, the stoichiometric coefficients should be deduced so that the stoichiometric matrix can be presented. The important assumptions and simplifications behind the model for ASP are enumerated. Using the matrix, mass balance equation and consistent units, the stoichiometric coefficients in the eight processes are exclusively deduced one by one.

  19. 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

    1994-01-01

    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...... denitrification momentarily occurs. This approach serves to increase the denitrification rate on demand, thereby allowing the accumulation of nitrate and nitrite during periods of peak nitrogen loading to be reduced or avoided. A pilot plant demonstration of the control strategy using acetate as COD source...

  20. Utilization of activated sludge plants for enhanced treatment of combined sewage.

    Science.gov (United States)

    Nikolavcic, B; Svardal, K; Wandl, G; Günther, N; Spatzierer, G

    2008-01-01

    A process is introduced which utilizes secondary clarifiers for the treatment of combined sewage. Under storm water conditions, surplus sewage bypasses the aeration tanks after primary treatment and is directly introduced into the secondary clarifiers. The hydraulic capacity of existing activated sludge plants can be increased without additional tank volume. Particulate matter as well as dissolved compounds are removed to a high extent. Investigations on a full scale treatment plant (100,000 p.e.) show that the effluent quality is comparable with full biological treatment, even if the hydraulic loading is increased by 50%. IWA Publishing 2008.

  1. Microbial electrolysis contribution to anaerobic digestion of waste activated sludge, leading to accelerated methane production

    DEFF Research Database (Denmark)

    Liu, Wenzong; Cai, Weiwei; Guo, Zechong

    2016-01-01

    Methane production rate (MPR) in waste activated sludge (WAS) digestion processes is typically limitedby the initial steps of complex organic matter degradation, leading to a limited MPR due to sludgefermentation speed of solid particles. In this study, a novel microbial electrolysis AD reactor (ME......-AD) wasused to accelerate methane production for energy recovery from WAS. Carbon bioconversion wasaccelerated by ME producing H2 at the cathode. MPR was enhanced to 91.8 gCH4/m3 reactor/d in themicrobial electrolysis ME-AD reactor, thus improving the rate by 3 times compared to control conditions (30.6 gCH4...

  2. Performance of Conventional Activated Sludge to Remove Nitrogen Compounds from Tomato Factory Wastewater

    Directory of Open Access Journals (Sweden)

    Meghdad Pirsaheb

    2012-10-01

    Full Text Available Today discharge of raw or treated wastewater containing nutrients (nitrogen and phosphorus compounds to the surface water causing an Utrification phenomenon, will be due to excessive growth of algae in the receptive water source. Each of the of wastewater treatment system, providing principled design and operation can be reduced nutrients to standard level [1]. The purpose of this study was to evaluate the efficacy of conventional activated sludge systems to remove nitrogen compounds from wastewater of Kermanshah Rojintak tomato factory and comparison of the final effluent quality with discharge standards to water resource and reuse it in agricultural irrigation in term of nitrogen compounds are considered.

  3. Parameter subset selection for the dynamic calibration of activated sludge models (ASMs): experience versus systems analysis

    DEFF Research Database (Denmark)

    Ruano, MV; Ribes, J; de Pauw, DJW

    2007-01-01

    In this work we address the issue of parameter subset selection within the scope of activated sludge model calibration. To this end, we evaluate two approaches: (i) systems analysis and (ii) experience-based approach. The evaluation has been carried out using a dynamic model (ASM2d) calibrated...... based approaches which excluded them from their analysis. Systems analysis reveals that parameter significance ranking and size of the identifiable parameter subset depend on the information content of data available for calibration. However, it suffers from heavy computational demand. In contrast...

  4. Biodegradation of pharmaceuticals in hospital wastewater by a hybrid biofilm and activated sludge system (Hybas)

    Energy Technology Data Exchange (ETDEWEB)

    Escolà Casas, Mònica [Environmental Science, Aarhus University, Frederiksborgsvej 399, 4000 Roskilde (Denmark); Chhetri, Ravi Kumar [Department of Environmental Engineering, Technical University of Denmark, Miljøvej 113, 2800 Kgs. Lyngby (Denmark); Ooi, Gordon [Environmental Science, Aarhus University, Frederiksborgsvej 399, 4000 Roskilde (Denmark); Hansen, Kamilla M.S. [Department of Environmental Engineering, Technical University of Denmark, Miljøvej 113, 2800 Kgs. Lyngby (Denmark); Litty, Klaus [Department of Chemistry and Biotechnology, Danish Technological Institute, Kongsvang Allé 29, 8000 Aarhus C (Denmark); Christensson, Magnus [AnoxKaldnes, Klosterängsvägen 11A, 226 47 Lund (Sweden); Kragelund, Caroline [Department of Chemistry and Biotechnology, Danish Technological Institute, Kongsvang Allé 29, 8000 Aarhus C (Denmark); Andersen, Henrik R. [Department of Environmental Engineering, Technical University of Denmark, Miljøvej 113, 2800 Kgs. Lyngby (Denmark); Bester, Kai, E-mail: kb@envs.au.dk [Environmental Science, Aarhus University, Frederiksborgsvej 399, 4000 Roskilde (Denmark)

    2015-10-15

    Hospital wastewater contributes a significant input of pharmaceuticals into municipal wastewater. The combination of suspended activated sludge and biofilm processes, as stand-alone or as hybrid process (hybrid biofilm and activated sludge system (Hybas™)) has been suggested as a possible solution for hospital wastewater treatment. To investigate the potential of such a hybrid system for the removal of pharmaceuticals in hospital wastewater a pilot plant consisting of a series of one activated sludge reactor, two Hybas™ reactors and one moving bed biofilm reactor (MBBR) has been established and adapted during 10 months of continuous operation. After this adaption phase batch and continuous experiments were performed for the determination of degradation of pharmaceuticals. Removal of organic matter and nitrification mainly occurred in the first reactor. Most pharmaceuticals were removed significantly. The removal of pharmaceuticals (including X-ray contrast media, β-blockers, analgesics and antibiotics) was fitted to a single first-order kinetics degradation function, giving degradation rate constants from 0 to 1.49 h{sup −1}, from 0 to 7.78 × 10{sup −1} h{sup −1}, from 0 to 7.86 × 10{sup −1} h{sup −1} and from 0 to 1.07 × 10{sup −1} h{sup −1} for first, second, third and fourth reactors respectively. Generally, the highest removal rate constants were found in the first and third reactors while the lowest were found in the second one. When the removal rate constants were normalized to biomass amount, the last reactor (biofilm only) appeared to have the most effective biomass in respect to removing pharmaceuticals. In the batch experiment, out of 26 compounds, 16 were assessed to degrade more than 20% of the respective pharmaceutical within the Hybas™ train. In the continuous flow experiments, the measured removals were similar to those estimated from the batch experiments, but the concentrations of a few pharmaceuticals appeared to increase

  5. Adsorption of reactive brilliant red K-2BP on activated carbon developed from sewage sludge

    Institute of Scientific and Technical Information of China (English)

    Jiankun XIE; Qinyan YUE; Hui YU; Wenwen YUE; Renbo LI; Shengxiao ZHANG; Xiaona WANG

    2008-01-01

    Activated carbon was prepared from the sewage sludge of municipal wastewater treatment plant by chemical activation (activation reagent is ZnCl2) and was used for the adsorption of dye (reactive brilliant red K-2BP). The impact of adsorbent amount, adsorption time and pH value on adsorption effect, the adsorption kinetics, and the adsorption thermodynamics were dis-cussed according to batch adsorption tests. The results indicated that the activated carbon developed from sewage sludge (ACSS), which was mesoporous, possessed opened porous structures. The iodine number of the ACSS was heavy metals in the leachate didn't exceed the contents limit. The adsorption kinetics of reactive brilliant red K-2BP on the ACSS was accorded with the two-step kinetics rate equation and pseudo-second-order kinetics equation. Compared to the Freundlich isotherm equation, the Langmuir isotherm equation showed better applicability for the adsorption. The adsorption which was favorable was an endothermic (enthalpy △H > 0) and spontaneous (flee energy △G 0).

  6. Removal of fluoride in aqueous solution by adsorption on acid activated water treatment sludge

    Science.gov (United States)

    Vinitnantharat, Soydoa; Kositchaiyong, Sriwilai; Chiarakorn, Siriluk

    2010-06-01

    This paper reports the use of a pellet of adsorbent made from water treatment sludge (S) and acid activated water treatment sludge (SH) for removal of fluoride in the batch equilibration technique. The influence of pH, adsorbent dosage, temperature and effect of other ions were employed to find out the feasibility of acid activated adsorbent to remove fluoride to the permissible concentration of 0.7 mg/L. The results from the adsorption isotherm followed both Langmuir and Freundlich models and the highest fluoride removal was found for adsorbent activated with acetic acid at 2.0 mol/L. The optimum adsorbent dosage was found at 40 g/L, 0.01 mol/L acid activated adsorbent which was able to adsorb fluoride from 10 down to 0.11 mg/L. The adsorption capacity was decreased when the temperature increased. This revealed that the adsorption of fluoride on SH was exothermic. In the presence of nitrate and carbonate ions in the aqueous solution, fluoride removal efficiency of SH decreased from 94.4% to 86.6% and 90.8%, respectively. However, there is no significant effect in the presence of sulfate and chloride ions.

  7. Comparative study of phenol and cyanide containing wastewater in CSTR and SBR activated sludge reactors.

    Science.gov (United States)

    Papadimitriou, C A; Samaras, P; Sakellaropoulos, G P

    2009-01-01

    The objectives of this work were the examination of the performance of two bench scale activated sludge systems, a conventional Continuous Stirring Tank Reactor (CSTR) and a Sequential Batch Reactor (SBR), for the treatment of wastewaters containing phenol and cyanides and the assessment of the toxicity reduction potential by bioassays. The operation of the reactors was monitored by physicochemical analyses, while detoxification potential of the systems was monitored by two bioassays, the marine photobacterium Vibrio fischeri and the ciliate protozoan Tetrahymena thermophila. The reactors influent was highly toxic to both organisms, while activated sludge treatment resulted in the reduction of toxicity of the influent. An increased toxicity removal was observed in the SBR; however CSTR system presented a lower ability for toxicity reduction of influent. The performance of both systems was enhanced by the addition of powdered activated carbon in the aeration tank; activated carbon upgraded the performance of the systems due to the simultaneous biological removal of pollutants and to carbon adsorption process; almost negligible values of phenol and cyanides were measured in the effluents, while further toxicity reduction was observed in both systems.

  8. Genomic and in situ investigations of the novel uncultured Chloroflexi associated with 0092 morphotype filamentous bulking in activated sludge.

    Science.gov (United States)

    McIlroy, Simon Jon; Karst, Søren Michael; Nierychlo, Marta; Dueholm, Morten Simonsen; Albertsen, Mads; Kirkegaard, Rasmus Hansen; Seviour, Robert James; Nielsen, Per Halkjær

    2016-09-01

    Overgrowth of filamentous bacteria in activated sludge wastewater treatment plants (WWTPs) leads to impaired sludge settleability, a condition known as bulking, which is a common operational problem worldwide. Filaments with the Eikelboom 0092 morphotype are commonly associated with such bulking episodes. Members of the uncultured B45 phylotype, which is embraced within the phylum Chloroflexi, were recently shown to exhibit this morphology. Although these organisms are among the most abundant populations recorded in activated sludge processes, nothing is known about their metabolic characteristics. In this study, a genome sequence, representing the B45 phylotype, was retrieved from a metagenome generated from an activated sludge WWTP. The genome consisted of two chromosomes and one plasmid, which were 4.0, 1.0 and 0.04 Mbps in size, respectively. A metabolic model was constructed for this organism, based on annotation of its genome, showing its ability to generate energy by respiration, utilizing oxygen, nitrite or nitrous oxide as electron acceptors, or by fermentation of sugars. The ability of B45 members to ferment sugars under anaerobic conditions was validated in situ with microautoradiography-fluorescence in situ hybridization. The provisional name of 'Candidatus Promineofilum breve' is proposed for this species. This study represents the first detailed information on an uncultured genus of filamentous organisms from activated sludge.

  9. Innovative combination of electrolysis and Fe(II)-activated persulfate oxidation for improving the dewaterability of waste activated sludge.

    Science.gov (United States)

    Zhen, Guang-Yin; Lu, Xue-Qin; Li, Yu-You; Zhao, You-Cai

    2013-05-01

    The feasibility of electrolysis integrated with Fe(II)-activated persulfate (S2O8(2-)) oxidation to improve waste activated sludge (WAS) dewaterability was evaluated. The physicochemical properties (sludge volume (SV), total suspended solids (TSS) and volatile suspended solids (VSS)) and extracellular polymeric substances (EPS), including slime EPS, loosely bound EPS (LB-EPS) and tightly bound EPS (TB-EPS) were characterized to identify their exact roles in sludge dewatering. While dewaterability negatively corresponded to LB-EPS, TB-EPS, protein (PN) and polysaccharide (PS) in LB-EPS and TB-EPS, it was independent of SV, TSS, VSS, slime EPS and PN/PS. Further study through scanning electron microscope (SEM) verified the entrapment of bacterial cells by TB-EPS, protecting them against electrolysis disruption. Comparatively, electrolysis integrated with S2O8(2-)/Fe(II) oxidation was able to effectively disrupt the protective barrier and crack the entrapped cells, releasing the water inside EPS and cells. Therefore, the destruction of both TB-EPS and cells is the fundamental reason for the enhanced dewaterability.

  10. Evaluation of alkaline phosphatase activity and availability of various P fractions for bean (Phaseolus vulgaris in some calcareous soils amended with municipal sewage sludge

    Directory of Open Access Journals (Sweden)

    T. Raeisi

    2014-07-01

    Full Text Available To evaluate the relationship of various P fractions and alkaline phosphatase activity with bean indices growing in 10 calcareous soils, amended with municipal sewage sludge from Chaharmahal-Va-Bakhtiari province, a greenhouse research was carried out. Soil samples were incubated for one month with sludge at a rate equivalent to 1% (w/w. Then, the P fractions, including P adsorbed by Fe and Al oxides (]NaOH+CB]-P, occluded P (CBD-P and P absorbed by Ca (HCl-P, were determined by Olsen and Summers' sequential fractionation procedure. Furthermore, total P, organic P and residual P were determined. Also, alkaline phosphatase activity was measured. A pot experiment in a completely randomized design with three replications in the ten soils was done to evaluate the bean plant indices. The results showed that the amount of P fractions decreased in the following order: HCl-P>residual-P>]NaOH+CB]-P > OP>CBD-P. The results also indicated that alkaline phosphatase activity was significantly correlated with CBD-P fraction, organic P and total P. In addition, significant correlations were found between ([NaOH+CB]-P and HCl-P and plant shoots. In general, the results of this research showed that P fractionation method appears to be a powerful tool to identify the P status and availability in the soils amended with sewage sludge.

  11. Identification of selected microorganisms from activated sludge capable of benzothiazole and benzotriazole transformation.

    Science.gov (United States)

    Kowalska, Katarzyna; Felis, Ewa

    2015-01-01

    Benzothiazole (BT) and benzotriazole (BTA) are present in the environment - especially in urban and industrial areas, usually as anthropogenic micropollutants. BT and BTA have been found in the municipal and industrial wastewater, rivers, soil, groundwater, sediments and sludge. The origins of those substances' presence in the environment are various industry branches (food, chemical, metallurgical, electrical), households and surface runoff from industrial areas. Increasingly strict regulations on water quality and the fact that the discussed compounds are poorly biodegradable, make them a serious problem in the environment. Considering this, it is important to look for environmentally friendly and socially acceptable ways to remove BT and BTA. The aim of this study was to identify microorganisms capable of BT and BTA transformation or/and degradation in aquatic environment. Selected microorganisms were isolated from activated sludge. The identification of microorganisms capable of BT and BTA removal was possible using molecular biology techniques (PCR, DNA sequencing). Among isolated microorganisms of activated sludge are bacteria potentially capable of BT and BTA biotransformation and/or removal. The most common bacteria capable of BT and BTA transformation were Rhodococcus sp., Enterobacter sp., Arthrobacter sp. They can grow in a medium with BT and BTA as the only carbon source. Microorganisms previously adapted to the presence of the studied substances at a concentration of 10 mg/l, showed a greater rate of growth of colonies on media than microorganisms unconditioned to the presence of such compounds. Results of the biodegradation test suggest that BT was degraded to a greater extent than BTA, 98-100% and 11-19%, respectively.

  12. DETERMINATION OF ACTIVATED SLUDGE MODEL ASDM PARAMETERS FOR WASTE WATER TREATMENT PLANT OPERATING IN THE SEQUENTIAL–FLOW TECHNOLOGY

    Directory of Open Access Journals (Sweden)

    Dariusz Zdebik

    2015-01-01

    Full Text Available This paper presents a method for calibration of activated sludge model with the use of computer program BioWin. Computer scheme has been developed on the basis of waste water treatment plant operating in the sequential – flow technology. For calibration of the activated sludge model data of influent and treated effluent from the existing object were used. As a result of conducted analysis was a change in biokinetic model and kinetic parameters parameters of wastewater treatment facilities. The presented method of study of the selected parameters impact on the activated sludge biokinetic model (including autotrophs maximum growth rate, the share of organic slurry in suspension general operational, efficiency secondary settling tanks can be used for conducting simulation studies of other treatment plants.

  13. Comparing activated sludge and aerobic granules as microbial inocula for phenol biodegradation

    Energy Technology Data Exchange (ETDEWEB)

    Tay, S.T.L.; Moy, B.Y.P.; Maszenan, A.M.; Tay, J.H. [Environmental Engineering Research Centre, School of Civil and Environmental Engineering, Nanyang Technological Univ., Singapore (Singapore)

    2005-06-01

    Activated sludge and acetate-fed granules were used as microbial inocula to start up two sequencing batch reactors (R1, R2) for phenol biodegradation. The reactors were operated in 4-h cycles at a phenol loading of 1.8 kg m{sup -3} day{sup -1}. The biomass in R1 failed to remove phenol and completely washed out after 4 days. R2 experienced initial difficulty in removing phenol, but the biomass acclimated quickly and effluent phenol concentrations declined to 0.3 mg l{sup -1} from day 3. The acetate-fed granules were covered with bacterial rods, but filamentous bacteria with sheaths, presumably to shield against toxicity, quickly emerged as the dominant morphotype upon phenol exposure. Bacterial adaptation to phenol also took the form of modifications in enzyme activity and increased production of extracellular polymers. 16S rRNA gene fingerprints revealed a slight decrease in bacterial diversity from day 0 to day 3 in R1, prior to process failure. In R2, a clear shift in community structure was observed as the seed evolved into phenol-degrading granules without losing species-richness. The results highlight the effectiveness of granules over activated sludge as seed for reactors treating toxic wastewaters. (orig.)

  14. Assessment of active methanogenic archaea in a methanol-fed upflow anaerobic sludge blanket reactor.

    Science.gov (United States)

    Cerrillo, Míriam; Morey, Lluís; Viñas, Marc; Bonmatí, August

    2016-12-01

    Methanogenic archaea enrichment of a granular sludge was undertaken in an upflow anaerobic sludge blanket (UASB) reactor fed with methanol in order to enrich methylotrophic and hydrogenotrophic methanogenic populations. A microbial community assessment, in terms of microbial composition and activity-throughout the different stages of the feeding process with methanol and acetate-was performed using specific methanogenic activity (SMA) assays, quantitative real-time polymerase chain reaction (qPCR), and high-throughput sequencing of 16S ribosomal RNA (rRNA) genes from DNA and complementary DNA (cDNA). Distinct methanogenic enrichment was revealed by qPCR of mcrA gene in the methanol-fed community, being two orders of magnitude higher with respect to the initial inoculum, achieving a final mcrA/16S rRNA ratio of 0.25. High-throughput sequencing analysis revealed that the resulting methanogenic population was mainly composed by methylotrophic archaea (Methanomethylovorans and Methanolobus genus), being also highly active according to the RNA-based assessment. SMA confirmed that the methylotrophic pathway, with a direct conversion of methanol to CH4, was the main step of methanol degradation in the UASB. The biomass from the UASB, enriched in methanogenic archaea, may bear great potential as additional inoculum for bioreactors to carry out biogas production and other related processes.

  15. Application of the selected classification models to the analysis of the settling capacity of the activated sludge – case study

    Directory of Open Access Journals (Sweden)

    Szeląg Bartosz

    2017-01-01

    Full Text Available The study presents the development of classification models for sedimentation of activated sludge using the artificial neural networks (ANN, logistic-regression (RL, and linear discrimination model (LDM. The input consisted of indicators of wastewater quantity and quality (biochemical oxygen demand, chemical oxygen demand, total suspended solids, total nitrogen and total phosphorus at the inflow to the wastewater treatment plant and operational characteristic of the bioreactor (pH, temperature of activated sludge, mixed liquor suspended solids, concentration of oxygen in the nitrification chamber, amount of PIX dosing.The prediction quality of the developed models was measured with: sensitivity, specificity, and computed errors. The calculations of the sedimentation were performed for sludge volume index (SVI. The results indicate that successful predictions were obtained using ANN, RL and LDM methods, which is supported by the fit of computations to measurement results. The study shows that for the wastewater treatment plant of concern, sedimentation properties can be obtained using only the loads of organic compounds, mixed liquor suspended solids, temperature, pH of activated sludge, concentration of oxygen in the nitrification chamber and amount of PIX dozing. Other analysed variables appear to be statistically insignificant for the sludge volume index.

  16. Potential and optimization of two-phase anaerobic digestion of oil refinery waste activated sludge and microbial community study

    Science.gov (United States)

    Wang, Qinghong; Liang, Ying; Zhao, Peng; Li, Qing X.; Guo, Shaohui; Chen, Chunmao

    2016-12-01

    Oil refinery waste activated sludge produced from oil wastewater biological treatment is a major industrial sludge. Two-phase anaerobic digestion of oil refinery waste activated sludge was studied for the first time. Thermal pretreatment under 170 °C is effective on sludge solubilization. At the optimum hydrolytic-acidogenic condition which was pH of 6.5, temperature of 55 °C and HRT of 2 days, 2754 mg/L volatile fatty acids (VFAs) were produced and acetic acid and butyric acid were the key components. Comparative studies of single-phase and two-phase anaerobic digestion in terms of organic removal, biogas production and methane concentration were conducted. The cumulative methane production and soluble COD (SCOD) removal efficiency in the two-phase system were 228 mL/g COD added and 77.8%, respectively, which were 1.6 and 2.1 times higher than those in single-phase anaerobic digestion. Such improved performance is attributed to intensification of dominant microbial population in separated reactors. Caloramator, Ureibacillus, Dechloromonas, Petrobacter, and T78 played important roles in hydrolytic-acidification and oil-organics degradation. Syntrophic bacteria in the family Porphyromonadaceae and the genus Anaerobranca provide acetate for methanogen. The results demonstrated the potential and operating condition of two-phase anaerobic digestion in treatment of oil refinery waste activated sludge.

  17. Potential and optimization of two-phase anaerobic digestion of oil refinery waste activated sludge and microbial community study.

    Science.gov (United States)

    Wang, Qinghong; Liang, Ying; Zhao, Peng; Li,