• Title, Summary, Keyword: COD reduction

Search Result 287, Processing Time 0.034 seconds

Numerical Prediction for Reduction of Oxygen Deficient Water Mass by Ecological Model in Jinhae Bay (생태계모텔에 의한 진해만의 빈산소수괴 저감예측)

  • Lee, In-Cheol;Kong, Hwa-Hun;Yoon, Seok-Jin
    • Journal of Ocean Engineering and Technology
    • /
    • v.22 no.5
    • /
    • pp.75-82
    • /
    • 2008
  • As a basic study for establishing a countermeasure for an oxygen deficient water mass (ODW), we investigated the variation of ODW volume according to the enforced total pollution load management in Jinhae Bay. This study estimated the inflowing pollutant loads into Jinhae Bay and predicted the reduction in ODW by using a sediment-water ecological model (SWEM). The result obtained in this study are summarized as follows: 1) The daily average pollutant loads of COD, SS, TN, TP, DIN, and DIP inflowing into Jinhae bay in 2005 were estimated to be about 12,218 kg-COD/day, 91,884 kg-SS/day, 5,292 kg-TN/day, 182 kg-TP/day, 4,236 kg-DIN/day, and 130 kg-DIP/day. 2) The calculated results of the tidal current by the hydrodynamic model showed good agreement with the observed currents. Also, an ecological model well reproduced the spatial distribution of the water quality in the bay. 3) This study defined the ODWDI (ODW decreasing index) in order to estimate the ODW decreasing volume caused by a reduction in the inflowing pollutant loads. As a result, the ODWDI was predicted to be about 0.91 (COD 30% reduction), 0.87 (COD 50% reduction), 0.79 (COD 70% reduction), 0.85 (ALL 30% reduction), 0.66 (ALL 50% reduction), and 0.45 (ALL 70% reduction). The ODW volume was decreased 1.5 $\sim$ 2.6 times with a reduction in the COD, TN, and TP inflowing pollutant loads compared to a reduction in just the COD inflowing pollutant load. Therefore, it is necessary to enforce total pollution load management, not only for COD, but also fm TN and TP.

Effects on bycatch reduction in a shaking cod end generated by canvas in a shrimp beam trawl

  • Kim, Yonghae;Whang, Dae-Sung
    • Journal of the Korean Society of Fisheries and Ocean Technology
    • /
    • v.50 no.3
    • /
    • pp.342-350
    • /
    • 2014
  • An active stimulating device, such as a fluttering net or canvas attached to the end of a cod end generating a shaking motion, could help to encourage the escape of juvenile fish positioned passively near the net. Field fishing trials using a shrimp beam trawl were carried out to examine the effect on the reduction of juvenile fish or other discard catch by generating a shaking movement of the cod end using an unbiased cap-like round canvas. The mean period of the shaking motion with the round canvas was ~14 s, and the mean amplitude was 0.4 m as measured by peak event analysis and the global wavelet method. The bycatch of juvenile fish in 14 trials decreased by ~30% and by ~25% using a steady cod end for the total bycatch using a shaking cod end in the shrimp beam trawl, while the marketing catch was similar between steady and shaking cod ends. There was no difference in the body size of the shrimp or fish and species composition between the steady and shaking cod ends. Above results demonstrate a new method for bycatch reduction using an active stimulating device, although more detailed studies are needed.

A Study on the Ozonation of Dyeing Wastewaters (오존에 의한 폐수처리에 관한 연구 -염색폐수의 COD처리 및 탈색에 관하여-)

  • 김덕묵;강부부
    • Journal of the Korean Professional Engineers Association
    • /
    • v.15 no.2
    • /
    • pp.24-31
    • /
    • 1982
  • This study concerns with the reduction of the COD and deceleration of dyeing wastewater from DAEGU city area by ozonation. The COD reduction by ozonation follows near linear relationships versus ozonation time, temperature and concentration. The color in dyeing wastewater and of dyes can he strikingly reduced as the water is quasi colorless after ozone treatment. COD reduction rate of wastewater was found not to be dependented on pH, however, high temperature gave better results, although economically not feasible. The ozonation of dyeing wastewater can give good results when dyes, scouring agent and sticking agents were pre-separated.

  • PDF

Study on the Optimization of Substrate and COD-reduction in the Cultivation of Yeast Candida rugosa in Sugar Beet Stillages (사탕무알콜증류폐액을 기질로 Candida rugosa 효모균체를 생산할 때 기질의 최적화와 COD감소에 대한 연구)

  • Lee, Ki-Young
    • Journal of the Korea Organic Resources Recycling Association
    • /
    • v.12 no.3
    • /
    • pp.119-125
    • /
    • 2004
  • Sugar beet stillages were used as a substrate for the production of single cell protein by a thermotolerant yeast Candida rugosa. 3 Stillage substrates were nutritionally optimized for the better production of yeast biomass and for the reduction of COD. The addition of Phosphorus(P) was required for all stillages, but Nitrogen(N) only when the residual sugar remained. The addition of P increased the biomass production to 23-61%. The addition of N increased the biomass production only a little, but when added together with P increased to 90%. The COD decreased to 26-46% when P was added, but decreased to 85% when P was added together with N.

  • PDF

A Study on the Reduction of Color in Dye Wastewaters by Physico-chemical Processes (물리, 화학적 처리방법에 의한 염색폐수의 색도제거에 관한 연구)

  • 이준석;김민호;김영규
    • Journal of Environmental Health Sciences
    • /
    • v.19 no.3
    • /
    • pp.29-35
    • /
    • 1993
  • This study was performed to obtain optimal conditions for reduction of color in dye wastewaters using coagulation-sedimentation processes with redox reactions. The reduction of color as well as organic matters variation was observed after coagulation-sedimentation processes using FeSO$_4$ $\cdot$ 7H$_2$O and NaOCl. Coagulation-redox reaction was done with the dose of Coagulant and oxidant at various pH values. Redox reaction was done through jar-mixing and aeration. The results of study were as follows: 1. In the coagulation-sedimentation processes using FeSO$_4$ $\cdot$ 7H$_2$O, color reduction was heigher at pH 3. With variance of dosage of FeSO$_4$ $\cdot$ 7H$_2$O, color reduction was higher at 250 mg/l. When coagulation-sedimentation using FeSO$_4$ $\cdot$ 7H$_2$O 250 mg/l was added at pH 3, the reduction of color, COD$_{Mn}$, and COD$_{Cr}$ showed 47.6%, 21.3% and 22.1%, respectively. 2. When NaOCI was added at level of 100 ppm in raw wastewater at pH 3, the reduction of color, COD$_{Mn}$, and COD$_{Cr}$ showed 30.2%, 5.5% and 6.2%, respectively. 3. After coagulation-sedimentation processes by addition of FeSO$_4$ $\cdot$ 7H$_2$O, when NaOCl was added at level of 250 mg/l in supernant, color reduction was 47.8% in aeration and 37.5% in jar-mixing. 4. Color reduction by aeration was higher than that by jar-mixing.

  • PDF

Water quality management of Jeiu Harbor using material cycle model(III) - Quantitative Management of Pollutant Loadings - (물질순환모델을 이용한 제주항의 수질관리(III) - 오염부하의 정량적 관리 -)

  • 조은일;강기봉
    • Journal of Environmental Science International
    • /
    • v.12 no.3
    • /
    • pp.307-317
    • /
    • 2003
  • In this study, the material cycle model was applied to suggest alternative management of water quality for Jeju Harbor. The distribution of COD, DIN (dissolved inorganic nitrogen) and DIP (dissolved inorganic phosphorus) concentrations was reasonably reproduced by simulations on the model area of the Jeju Harbor using a material cycle model. The simulations of COD, DIN and DIP concentrations were performed under the conditions of 20∼100% pollution loadings reductions from pollution sources. In case of the 100% reduction of the input loads from Sanzi river, concentrations of COD, DM and DIP were reduced to 39%, 78% and 52%, respectively at Jeju harbor. In contrast, in case of the pollutant loadings reductions from sediment, the effect of DIN and DIP reduction relatively seemed to increase around the center of study area. The 95% reduction of the pollutant loadings from river and sediment is required to meet the COD and nutrients concentration of second grade of ocean water quality criteria.

Chemical Coagulation Treatment Using Alum and PACl in Complex Wastewater (Alum과 PACl을 이용한 응집처리)

  • Sung, Il-Wha
    • Journal of Environmental Health Sciences
    • /
    • v.35 no.1
    • /
    • pp.53-57
    • /
    • 2009
  • In order to treat the complex wastewater containing organic compound and solids, pre-treatment system associated with molecular separation process were investigated. The reductions of COD and turbidity were obtained after coagulation processes using Alum (Aluminium sulfate, $Al_2(SO_4)_2{\cdot}18H_{2}O$) and PACl (poly aluminium chloride as 17% $Al_{2}O_{3}$). The results of study were as follows: using variable dosage of Alum, COD removal was highest at 4,000 mg/l, and the reduction of COD and turbidity was 42% and 92%, respectively. The optimum coagulation would be effective at pH 7.3 than pH 9.0 by the addition of alum at a concentration of 6,000 mg/l and PACl was add at 4.25% in raw complex wastewater with 2,000 mg/l alum at pH 7.3, the reduction of COD was reduced by 32%. But coagulation aid experiments indicated that PACl would be more effective in sludge separation ability than COD removal efficiency.

A Study on Treatment Characteristics of the Phenol and Catechol using on Anaerobic Fluidized Bed Reactor (혐기성 유동층 반응기를 이용한 페놀과 카테콜의 처리특성에 관한 연구)

  • 김민수;박동일;홍종순;장인용
    • Journal of Environmental Health Sciences
    • /
    • v.24 no.1
    • /
    • pp.1-8
    • /
    • 1998
  • This study was carried to investigate the treatment characteristics of the phenol and catechol with an anaerobic fluidized bed reactor(AFBR) having a dimension of 9 cm i.d. and 1.25 m height. The reactor was operated at $35\pm 1\circ$C. The COD concentration of the effluent, the gas production rate and the composition of gas were measured to determine the performance of the AFBR as the hydraulic retention time(HRT) was decreased from 2 days to i day at 600 mg/l of the phenol and catechol concentration. Stable treatment of the phenol wastewater could be achieved with the AFBR at 18 days but the catechol wastewater couldn't be. At HRT 2 days, the phenol wastewater showed the COD reduction efficiency of 93% and the gas production of 2.7 l/day and the catechol wastewater was obtained the COD reduction efficiency of 82% and the gas production of 0.72 l/day. Also at HRT 1 day the phenol and catechol wastewater showed the COD reduction efficiency of 95% and 73% and the gas production of 4.0 l/day and 1.25 l/day, respectively.

  • PDF

Treatment of ETA wastewater using GAC as particle electrodes in three-dimensional electrode reactor (활성탄 충진 3D 복극전기분해조를 이용한 ETA 처리)

  • Kim, Ran;Kim, Yu-Jin;Shin, Ja-Won;Kim, Jeong-Joo;Park, Joo-Yang
    • Journal of Korean Society of Water and Wastewater
    • /
    • v.27 no.2
    • /
    • pp.241-249
    • /
    • 2013
  • Ethanolamine (ETA) is widely used for alkalinization of water in steam cycles of nuclear power plants with pressurized water reactor. When ETA contained wastewater was released, it could increase COD and T-N. The treatment of the COD and T-N from ETA wastewater was investigated using the GAC as particle electrodes in three-dimensional electrode reactor (TDE). This study evaluated the effectiveness of GAC as particle electrode using different packing ratio at 300 V. The results showed that GAC-TDE could reduce ETA much more efficiently than ZVI-TDE at the mass ratio of GAC to insulator, 1:2. Additionally, The effect of applied electric potential to COD and T-N reduction was investigated. The results showed the high COD, T-N reduction and current efficiency at the low electric potential. Using the GAC-TDE will provide a better ETA reduction with reducing electrical potential dissipation.

The Effects of Light Intensity, Inoculum Size, and Cell Immobilisation on the Treatment of Sago Effluent with Rhodopseudomonas palustris Strain B1

  • Ibrahim, Shaliza;Vikineswary, S.;Al-Azad, Sujjat;Chong, L.L.
    • Biotechnology and Bioprocess Engineering:BBE
    • /
    • v.11 no.5
    • /
    • pp.377-381
    • /
    • 2006
  • A study was carried out to determine a suitable light intensity and inoculum size for the growth of Rhodopseudomonas palustris strain B1. The pollution reduction of sago effluent using free and immobilised R. palustris cells was also evaluated. The growth rate in glutamatemalate medium was highest at 4 klux compared to 2.5 and 3 klux. The optimal inoculum size was 10% (v/v). Both the COD and BOD of the sago effluent were reduced by 67% after three days of treatment. The difference in biomass production or BOD and COD removal with higher inoculum sizes of 15 and 20% was minimal. This could be attributed to limited nutrient availability in the substrate. The use of immobilised cells of R. palustris reduced the pollution load 10% less compared to pollution reduction by free cells. Hence, there was no significant difference in using free or immobilised cells for the treatment of sago effluent.