• Title, Summary, Keyword: wastewaters

Search Result 169, Processing Time 0.034 seconds

PCR-T- RFLP Analyses of Bacterial Communities in Activatced Sludges in the Aeration Tanks of Domestic and Industrial Wastewater Treatment Plants

  • RHO SANG CHUL;AN NAN HEE;AHN DAE HEE;LEE KYU HO;LEE DONG HUN;JAHNG DEOK JIN
    • Journal of Microbiology and Biotechnology
    • /
    • v.15 no.2
    • /
    • pp.287-295
    • /
    • 2005
  • In order to compare bacteria] community structure and diversity in activated sludges, terminal restriction fragment length polymorphism (T-RFLP) of PCR-amplified 16s rDNAs was analyzed for 31 domestic and industrial wastewater treatment plants (WTPs). Regardless of the characteristics of the wastewaters, the bacteria] community structures of activated sludges appeared diverse and complex. In particular, activated sludges in domestic WTPs contained higher bacterial diversity than those in industrial WTPs. It was also found that terminal restriction fragment (T-RF) profiles derived from domestic WTPs were very similar with each other, although activated sludges were collected from different plants at different locations. Interestingly, activated sludges of a WTP where restaurant and toilet sewages of a company were managed showed a bacterial community structure similar to that of domestic WTPs. Activated sludges in leather industria] WTPs also showed a high similarity. However, other wastewaters possessed different bacterial communities, so that overall similarity was as low as about $30\%$. Since activated sludges from WTPs for domestic wastewaters and a company sewage appeared to hold similar bacterial communities, it was necessary to confirm if similar wastewaters induce a similar bacterial community. To answer this question, analysis of T-RFs for activated sludges, taken from another 12 domestic WTPs, was conducted by using a 6­FAM$^{TM}$-Iabeled primer and an automated DNA sequencer for higher sensitivity. Among 12 samples, it was again found that T-RF profiles of activated sludges from Yongin, Sungnam, Suwon, and Tancheon domestic WTPs in Kyonggi-do were very similar with each other. On the other hand, T-RF profiles of activated sludges from Shihwa and Ansan WTPs were quite different from each other. It was thought that this deviation was caused by wastewaters, since Ansan and Shihwa WTPs receive both domestic and industrial wastewaters. From these results, it was tentatively concluded that similar bacterial communities might be developed in activated sludges, if WTPs treat similar wastewaters.

Anaerobic codigestion of urban solid waste fresh leachate and domestic wastewaters: Biogas production potential and kinetic

  • Moujanni, Abd-essamad;Qarraey, Imane;Ouatmane, Aaziz
    • Environmental Engineering Research
    • /
    • v.24 no.1
    • /
    • pp.38-44
    • /
    • 2019
  • The Biochemical Methane Potential (BMP) of fresh leachate and domestic wastewaters codigestion was determined by laboratory Bach Tests at $35^{\circ}C$ over a period of 90 d using a wide range of leachates volumetric ratios from 0% to 100%. To simulate wastewaters plant treatment step, all the ratios were first air stripped for 48 h before anaerobic incubation. The kinetic of biogas production was assessed using modified Gompertz model and exponential equation. The results obtained showed that cumulative biogas production was insignificant in the case of wastewaters monodigestion while the codigestion significantly improves the BMP. Air stripping pretreatment had positive effect on both ammonium concentration and volatiles fatty acids with reduction up to 75% and 42%, respectively. According to the Modified Gompertz model, the optimal anaerobic co-digestion conditions both in terms of maximal biogas potential, start-up period and maximum daily biogas production rate, could be achieved within large leachate volumetric ratios from 25% to 75% with a maximum BMP value of 438.42 mL/g volatile solid at 50% leachate ratio. The positive effect of codigestion was attributed to a dilution effect of chemical oxygen demand and volatile fatty acid concentrations to optimal range that was between 11.7 to $32.3gO_2/L$ and 2.1 to 7.4 g/L, respectively. These results suggested that the treatment of fresh leachate by their dilution and co digestion at wastewaters treatment plants could be a promising alternative for both energetic and treatment purposes.

Performance Evaluation of Anaerobic Bioreactors and Effects of Ammonia on Anaerobic Digestion in Treating Swine Wastewaters

  • Lee, Gook-Hee;Seo, Jun-Won;Kim, Jong-Soo
    • Korean Journal of Environmental Agriculture
    • /
    • v.25 no.3
    • /
    • pp.195-201
    • /
    • 2006
  • The operational characteristics of anaerobic bioreactors in treating swine wastewater were evaluated upto hydraulic retention time (HRT) of 1 day and organic loading rate (OLR) of $5.1kg-COD/m^3{\cdot}d$ for 200 days. The bioreactors were effective in treating swine wastewaters with COD removal efficiency of $78.9{\sim}81.5%$ and biogas generation of $0.39{\sim}0.59m^3/kg-COD_r$ at OLR of $1.1{\sim}2.2kg-COD/m^3{\cdot}d$. The two-stage ASBF anaerobic bioreactors was effective in treating different characteristics of swine wastewaters since they showed high and stable COD removal efficiency at high OLR due to effective retention of biomass by media and staging. The effects of ammonia on anaerobic digestion were investigated by operating two-stage ASBF reactors using swine wastewaters as influent without and with ammonia removal at HRT of $1{\sim}2$ days and OLR of $2.2{\sim}9.6kg-COD/m^3{\cdot}d$ for 250 days. The COD removal efficiency and biogas generation of two-stage ASBF reactors was decreased by increasing influent ammonia concentrations to 1,580 mg (T-N)/L with increasing OLR to $6.3kg-COD/m^3{\cdot}d$, while those were increased by maintaining influent ammonia concentrations below 340 mg (T-N)/L by MAP precipitation with increasing OLR to $9.6kg-COD/m^3{\cdot}d$. Initial inhibition of ammonia on anaerobic processes was observed at a concentration of 760 mg (T-N)/L and the COD removal efficiency and biogas generation dropped to 1/2 at ammonia concentration ranges of $1,540{\sim}1,870mg$ (T-N)/L. It is essential to remove ammonia in swine wastewaters to an initial inhibition level before anaerobic processes for the effective removal of COD.

Membrane Ultrafiltration for Apparent Molecular Weight Distributions of Dissolved Organic Matter

  • Seo, Jun-Won;Sa, Tongmin;Kim, Jong-Soo
    • Journal of Applied Biological Chemistry
    • /
    • v.43 no.1
    • /
    • pp.31-36
    • /
    • 2000
  • Apparent MWDs of DOM in natural waters and swine wastewaters were determined through membrane ultrafiltration. The nominal MWCOs of ultrafiltration membranes by the manufacturer were confirmed to be similar with those obtained from the ultrafiltration procedures employed in this study using six MW standard compounds. Natural waters showed a wide range of MWOs, but 62.4~87.5% were in the range of MW<10K. High MW fractions were preferentially removed through water treatment processes. Swine wastewater showed two major ranges of MWDs, 49.0% in <1K and 36% in >50k while anaerobically treated swine wastewaters showed 17.5~18.0% in <1K and 53.0~58.8% in <50K. The overall DOM was reduced during anaerobic treatment by 76.8~80.0% as COD; however. the percentage of low MW fractions decreased and that of the high MW fractions increased.

  • PDF

Nitrogen removal from wastewaters without carbon sources using microalgae

  • Lee, Kwang-Yong;Lee, Choul-Gyun
    • 한국생물공학회:학술대회논문집
    • /
    • /
    • pp.553-556
    • /
    • 2000
  • Possibility of biological nitrogen treatment was tested in wastewaters with low C/N ratio. Chlorella kessleri was inoculated at $10^6\;cell/mL$ of initial density in two different artificial wastewaters: one that contained glucose for organic carbon source and the other without carbon source. Nitrate could be successfully reduced below 10 mg $NO_3/mL$ from initial nitrate concentration of 560 mg $NO_3/mL$ in 10 days even in the wastewater without carbon source, This 98% removal of nitrate without extra organic carbon source lights up the future of biological wastewater treatment, where the insufficient ability of nitrogen removal is a major problem.

  • PDF

Ammonia Effects on Anaerobic Digestion of Swine Wastewaters (양돈폐수의 혐기성 소화에 대한 암모니아의 영향)

  • Kim, Jong-Soo
    • Journal of the Korea Organic Resources Recycling Association
    • /
    • v.10 no.1
    • /
    • pp.102-108
    • /
    • 2002
  • The effects of ammonia on mesophilic anaerobic digestion were investigated by operating lab-scale two-stage ASBF reactors using swine wastewaters as influent without and with ammonia removal at HRT of 1-2 days and OLR of $2.2{\sim}9.6kg-COD/m^3{\cdot}d$ for 250 days. The COD removal efficiency and biogas generation of two-stage ASBF reactors was decreased by increasing influent ammonia concentrations to 1,580 mg(T-N)/L with increasing OLR to $6.3kg-COD/m^3{\cdot}d$, while those were increased by maintaining influent ammonia concentrations below 340 mg(T-N)/L by MAP precipitation with increasing OLR to $9.6kg-COD/m^3{\cdot}d$. Initial inhibirion of ammonia on anaerobic processes was observed at a concentration of 760 mg(T-N)/L and the COD removal efficiency and biogas generation dropped to 1/2 at ammonia concentration ranges of 1,540~1,870 mg(T-N)/L. It is essential to remove ammonia in swine wastewaters to an initial inhibition level before anaerobic processes for the effective removal of COD.

  • PDF

Nitrogen Removal from Wastewaters by Microalgae Without Consuming Organic Carbon Sources

  • Lee, Kwang-Yong;Lee, Choul-Gyun
    • Journal of Microbiology and Biotechnology
    • /
    • v.12 no.6
    • /
    • pp.979-985
    • /
    • 2002
  • The possibility of microalgal nitrogen treatment was tested in wastewaters with a low carbon/nitrogen (C/N) ratio. Chlorella kessleri was cultured in the two different artificial wastewaters with nitrate as a nitrogen source: one contained glucose for an organic carbon source and the other without organic carbon sources. The growth rates of the two cultures were almost identical when the aeration rate was over 1 vvm. These results suggest that microalgae could successfully remove nitrogen from wastewater, as far as the mass transfer of $CO_2$, was not limited. Nitrate was successfully reduced to below 2 mg $NO_3^-$-N/ml from the initial nitrate concentration of 140 mg $NO_3^-$-N/ml in 10 days, even in the wastewater with no organic carbon source. Similar results were obtained when ammonium was used as the sole nitrogen source instead of nitrate. Higher concentrations of nitrogen of 140, 280, 560 and 1,400 mg/ml were also tested and similar amounts of nitrogen were removed by algal cultures without showing any substrate inhibition.

Mutagenic effects of industrial wastewaters by using umu-test (umu-test에 의한 일부 배출시설별 폐수의 변이원성 조사연구)

  • 김영환;손종렬;문영환;배은상
    • Journal of environmental and Sanitary engineering
    • /
    • v.11 no.2
    • /
    • pp.9-20
    • /
    • 1996
  • Genotoxicity/mutagenicity of organic chemicals in industrial wastewater was investigated using umu-test with a Salmonella typhimurium TA1535 strain. The tester strain was derived by introducing plasmid pSK 1002, which carried a umu C - lac Z fusion gene into S typhimurium TA1535, and tester strain in the presence microsomal activation proved to be the more sensitive maker of genotoxicity. Genotoxic responses were observed in concentrated with a blue-rayon column, from 14 plants tested. The results were as follow; 1. Genotoxic responses were observed in concentrated from nine plants(64.3%) tested. 2. The results show that genotoxic activity was particulary high in the untreated wastewaters and decreased in the treated wastewaters(35.7%) 3. No significant correlation was found between genotoxicity and water ollution indicators, such as COD and BOD.

  • PDF

Growth regime and environmental remediation of microalgae

  • Hammed, Ademola Monsur;Prajapati, Sanjeev Kumar;Simsek, Senay;Simsek, Halis
    • ALGAE
    • /
    • v.31 no.3
    • /
    • pp.189-204
    • /
    • 2016
  • Microalgal bioremediation of CO2, nutrients, endocrine disruptors, hydrocarbons, pesticides, and cyanide compounds have evaluated comprehensively. Microalgal mitigation of nutrients originated from municipal wastewaters, surface waters, and livestock wastewaters has shown great applicability. Algal utilization on secondary and tertiary treatment processes might provide unique and elegant solution on the removing of substances originated from various sources. Microalgae have displayed 3 growth regimes (autotrophic, heterotrophic, and mixotrophic) through which different organic and inorganic substances are being utilized for growth and production of different metabolites. There are still some technology challenges requiring innovative solutions. Strain selection investigation should be directed towards identification of algal that are extremophiles. Understanding and manipulation of metabolic pathways of algae will possible unfold solution to utilization of algae for mitigation of dissolve organic nitrogen in wastewaters.