최의소 , 황호재 Eui So Choi , Ho Jae Hwang

DOI: Vol.9(No.4) 201-207, 1993

It has been known that the sidestream, return water from sludge treatment process, increases organic and nutrient loading to the secondary treatment system. Therefore nutrient in the sidestream must be carefully controlled and reduced. Laboratory SBR and physicochemical treatments were carried out to remove the nutrient from it. Physico-chemical treatments removed phosphorus and nitrogen more effectively than SBR, and ammonia-air stripping with lime gave the most favorable results.

황규대 , 김복현 , 정윤진 , 조종복 Gye Dae Whang , Bok Hyun Kim , Woon Jin Chung , Jong Bok Cho

DOI: Vol.9(No.4) 208-215, 1993

The study was carried out to determine the kinetic coefficients and optimum treatment conditions and to evaluate the mass balance for sludge production in activated sludge process without primary clarifier. Eight bench-scale activated sludge units were operated under different operating conditions and by using incoming wastewater to two small scale wastewater treatment plants. The optimum treatment conditions were 8 hours of HRT and 8 days of SRT for $quot;A$quot; plant wastewater and 8 hours of HRT and 3 days of SRT for $quot;B$quot; plant wastewater. The calculated kinetic coefficients, sludge yield coefficients(Y) and decay coefficients (K_d) were 0.695 ㎎ MLVSS/㎎ COD, and 0.186 day^(-1) for $quot;A$quot; plant wastewater and 1.064 ㎎ MLVSS/㎎ COD, and 0.252 day^(-1) for $quot;B$quot; plant wastewater. The amount of sludge calculated by using the proposed solids mass balance model were well agreed with the amount of sludge produced from activated sludge process.

이윤석 , 신현준 Yung Seok Yi , Hyun Jun Shin

DOI: Vol.9(No.4) 216-223, 1993

This study examines the efficiencies of Imhoff tanks filled with plastic bottles and synthetic sponges, to improve the low efficiency of the conventional Imhoff tank. To evaluate the effectiveness of media, two Imhoff tanks with the reactor volume of 131 L, were installed and operated at the treatment site of an apartment complex in a small community. The laboratory Imhoff tank with reactor volume of 23 L was operated to examine the effects of aeration in the sedimentation chamber. At the HRT of 1 day, the Imhoff tanks filled with plastic bottles and synthetic sponges showed BOD removal efficiencies of 48.7% and 46%, respectively, and SS removal efficiencies of 71.1% and 76%, respectively. However, BOD removal efficiency of 80.1% and SS removal efficiency of 89.5% were obtained when the effluent of Imhoff tank was aerated in the sedimentation chamber.

마은애 , 정영희 , 구민선 , 정창호 , 민경희 Eun Ae Ma , Young Heui Jung , Min Sun Goo , Chang Ho Chung , Kyung Hee Min

DOI: Vol.9(No.4) 224-232, 1993

Seven strains of the bacteria capable of growing on phenol as the sole carbon source were isolated from wastewater. They were identified as Enterobacter cloacae SM9, Pseudomonas cepacia SM 16, Pseudomonas putida SM25, Pseudomonas putida SM38, Enterobacter cloacae SM50, Serratia marcescens SM55 and Corynebacterium sp. SM57. They were able to utilize benzoate, m-toluate, salicylate, p-aminobenzoate, p-hydroxybenzoate, catechol, naphthalene, benzene, toluene, aniline and xylene among hydrocarbons as their carbon source. All isolates were resistant to spectinomycin. All of them were shown to have resistance to the heavy metals such as Co, Cu, Zn, Ba, Ni. Only Caryaebacterium sp. SM57 was resistant to Hg.

마은애 , 정영희 , 구민선 , 정창호 , 민경희 Eun Ae Ma , Young Heui Jung , Min Sun Goo , Chang Ho Chung , Kyung Hee Min

DOI: Vol.9(No.4) 233-239, 1993

The optimum condition on biodegradation of phenol by Pseudomonas cepacia SM16, Serratia marcescens SM55 and Carynebacterium sp. SM57 was pH 7.0 and 1.5mM for carbon sources. These selected strains degraded 1.5mM phenol up to 70∼80% within 12 to 30 hours. Pseudomanas cepacia SM16, Serratia marcescens SM55 and Carynebacterium sp. SM57 were able to degrade benzoate, catechol, salicylate, and phenol through $quot;ortho-pathway$quot;. Phenol hydroxylase was induced by phenol but not by o-cresol, m-cresol and cresol.

이인선 , 신상철 , 정동일 In Seon Lee , Sang Chul Shin , Dhong Il Jung

DOI: Vol.9(No.4) 240-245, 1993

Estimations of the unit pollutant loading from point source have been conducted oftenly in korea and the results were used to calculate the amounts of pollutant from the point source. But survey for the estimation of the unit pollutant loading from non-point source were not performed sufficiently because of the variation of pollutant effluent factors such as the methods of fertilizing, the patterns of irrigation, rainfall occuring, land use. The stream flowrate measurement and soil column test was carried out to develop the estimation methods of the unit pollutant loading rate discharged from the non-point source. And it seemed that the unit pollutant loading discharged from the non-point source mainly depends on the characteristics of rainfall and amount of flowrate from the watershed. The unit BOD loading rate calculated by this methods were shown as 3.78㎏/㎡· day in forest area, 6.33㎏/㎡·day in farm dry field and 8.60㎏/㎡ ·day in rice paddy area.

황규대 , 윤치웅 , 김복현 , 조종복 , 정윤진 , 백성기 Gye Dae Whang , Chi Woong Yoon , Bok Hyun Kim , Jong Bok Cho , Yoon Jin Chung , Sung Gi Baek

DOI: Vol.9(No.4) 246-255, 1993

Wastes from hog farms can contribute considerable pollution loads to receiving streams because it contains high concentration of organic matters and nutrients. Therefore it is required to discharge after proper treatment. The objective of this study was to determine the optimum treatment conditions and to evaluate design parameters for a swine wastewater treatment plant. Three bench scale activated sludge units and two rotating biological contactor units were operated by using swine wastewater. Settling characteristics of suspended solids were very poor, and after 2 hour settling time, removal efficiency of organic matters and suspended solids were about 15% and 23%, respectively. Among the coagulants treated to improve the settleablity of suspended solids, ferric chloride showed the best result at dose concentration of 525㎎/ℓ. The activated sludge unit operated at 6 hours of HRT and 16 days of SRT produced the best quality of effluent. The kinetic coefficients, yield coefficient(Y₁), and decay coefficient(k_d), were 0.32㎎ MLSS/㎎ COD and 0.079 day ^(-1), respectively. RBC process showed about 90% SCOD and 86% TKN removal efficiency. The hydraulic loading did not affect the SCOD removal efficiency significantly. The kinetic coefficients, loading rate(P) and substrate saturation constant(Ks) were 13.7g SCOD/㎡/day and 32.7㎎ SCOD/ℓ, respectively for SCOD removal, and 0.73g TKN/㎡/ day and 25㎎ TKN/ℓ, respectively for TKN removal. Experimental results indicated that RBC process required much larger area than activated sludge process to produce the same quality of effluent.

전천규 , 노세원 , 박용남 Cheon Gue Jeon , Se Won No , Yong Nam Park

DOI: Vol.9(No.4) 256-259, 1993