본 연구는 고추 재배 시험을 통해서 발전소로부터 배출되는 저회 (BA, bottom ash)의 농업적 활용 가능성을 평가하고자 수행되었다. 저회의 시용수준은 5 (BA5), 10 (BA10), 15 (BA15) 및 20 (BA20) ton ha-1으로 조절하였으며, 대조구는 퇴비를 일반 기비로 사용한 관행처리 방법으로 하였다. 고추의 생육 특성은 퇴비 처리구가 저회 처리구에 비해 생육이 증가되었고, 저회 사용수준에 따른 고추의 생육은 전반적으로 BA15 ≓ BA10 > BA20 > BA5 처리구 순으로 증가되었다. 고추 재배 후 조사된 토양의 화학적 특성은 저회의 시용수준이 증가될수록 pH, EC, SOC, 그리고 CEC 함량이 증가되는 경향을 보였다. 특히, 작물의 생육과 관련이 깊은 pH, SOC 및 CEC의 지표는 저회 처리구가 대조구에 비해 각각 0.20~0.82, 1.16~8.92 g kg-1 및 0.29~0.74 cmolc kg-1 범위로 증가되어 저회가 토양 탄소 함량 증진을 포함한 토양 비옥도 개선에 효과적인 역할을 한 것으로 판단된다. 따라서 본 시험의 결과로 미루어 볼 때 저회의 시용은 관행처리에 비해 고추의 수확량은 적지만 토양환경을 개선하는데 효과적인 것으로 판단되어 토양개량제로서 저회의 농업적 활용은 가능하다고 판단된다.

본 연구는 당근 재배지에서 녹비작물의 토양환원 효과를 구명하기 위해 수단그라스 및 크로타라리아 의 토양환원이 당근의 생육, 수량 및 품질향상에 미치는 영향을 조사하였다. 당근 재배를 위한 처리조 건은 무처리구, NPK처리구(N-P2O5-K2O= 20-9.6-12.2kg 10a-1), 크로타라리아(파종량 6kg 10a-1), 수단그라스(파종량 6kg 10a-1) 및 수단글라스 + 크로타라리아(파종량 3+3kg 10a-1)의 5개 처리구로 시 험하였다. 당근재배지에서 전작물로 재배된 녹비작물의 질소(N), 인(P2O5), 칼륨(K2O), 칼슘(CaO) 및 마그네슘(MgO) 공급량은 크로타라리아의 경우 각각 9.2, 9.8, 7.4, 12.9 및 2.5kg 10a-1이었고, 수단그 라스의 경우 각각 8.7, 8.9, 45.7, 5.2 및 2.8kg 10a-1이었으며, 혼합처리구(수단그라스 + 크로타라리 아)의 경우 각각 8.8, 9.9, 29.5, 2.6 및 1.7kg 10a-1이었다. 당근 재배지에서 녹비작물의 토양환원 후 토양의 이화학적 특성을 조사한 결과 녹비작물 처리구가 대조구에 비해 용적밀도는 약간 감소하였으며, 공극율은 용적밀도와는 달리 약간 증가하는 경향을 보였다. 토양내 유기물, T-N 및 유효 P2O5 함량은 녹비작물 처리구가 전반적으로 대조구에 비해 증가하였다. 당근의 품질을 나타내는 클로로필, 당도 및 β-카로티노이드 함량은 모두 크로타라리아 처리구에서 가장 높았으며, 대조구에서 가장 낮은 함량을 보였다. 당근의 장해율은 녹비작물 처리구가 대조구에 비해 감소하는 경향이었고, 당근의 상품수량은 크로타라리아 + 수단그라스 혼합처리구(3,530kg 10a-1)가 대조구(2,101kg 10a-1)에 비해 68%의 증수효 과를 보였다. 따라서 당근 재배지에서 수단그라스 + 크로타라리아 혼합처리는 화학비료의 절감효과가 있으며, 특히 토양환원 후 토양의 물리성 및 화학성을 개선함으로써 당근의 상품수량 및 품질향상을 증 대시킬 수 있을 것으로 판단된다.

본 연구는 논토양에서 돈분액비의 시용이 화본과 및 두과 녹비작물의 생육과 양분공급량에 미치는 영향을 조사하기 위해, 화본과 녹비작물과 두과 녹비작물을 파종하여 돈분액비 시용유무에 따라 biomass 및 양분공급량을 조사하였다. 파종된 화본과 녹비작물은 호밀(Secale cereale L.)과 청보리(Hordeum vulgare L.)이었으며, 두과 녹비작물은 자운영(Astragalus sinicus L.)과 헤어리베치(Vicia villosa roth)이었다. 돈분액비를 투입함에 따라 녹비작물의 biomass는 유의성 있게 증가하였으며, 돈분액비 무시용구 대비 돈분액비 시용구의 biomass 증가율은 청보리(154%) > 호밀(138%) > 헤어리베치(45%) > 자운영(41%)순으로 높았다. 녹비작물의 양분공급량도 biomass와 마찬가지로 돈분액비를 투입함에 따라 유의성 있게 증가하는 경향이었으며, 돈분액비 무시용구 대비 돈분액비 시용구의 N, P2O5 및 K2O 공급량은 각각 205∼220, 109∼197 및 166∼184% 범위이었다. 돈분액비를 투입함에 따른 녹비작물의 biomass와 양분공급량 증가율은 전반적으로 두과 녹비작물보다 화본과 녹비작물에서 매우 우수한 경향이었다. 특히, 화본과 녹비작물의 증가된 양분공급량은 두과 녹비작물에 비해 약 3배 정도 더 높았다. 이상의 결과를 종합해 볼 때, 돈분액비 시용에 따른 양분이용효율은 화본과 녹비작물(호밀 및 청보리)이 두과 녹비작물(자운영 및 헤어리베치)에 비해 더 효과적인 것으로 판단된다.

본 연구는 시설하우스에서 비점오염원으로 인해 배출되는 오염된 농업배수를 인공습지에서 효과적으로 처리하기 위한 기초자료를 확보하기 위해 인공습지에서 여재종류, 조합방법 및 부하량에 따른 오염물질 정화효율을 평가하였다. 인공습지의 조합방법은 수직-수평흐름조, 수평-수직흐름조, 수평-수직-수평흐름조 및 수직-수평-수평흐름조로 구분하여 설계 및 시공하였으며, 여재는 왕사, 쇄석, 방해석 및 혼합여재로 구분하여 각 조에 충진하였다. 또한 농업배수 부하량을 150, 300, 600 L m-2 day-1으로 달리하여 오염물질의 처리효율을 조사하였다. 조합방법별 수처리효율은 HF-VF-HF 조합방법이 다른 조합방법에 비해 높은 처리효율을 보였으며, 최적여재는 COD 처리효율은 왕사가 가장 높았고, T-N은 쇄석, T-P는 방해석이 가장 높았다. 하지만 모든 처리효율과 경제성 부분을 고려하였을 때 최적여재는 혼합여재가 가장 효과적일 것으로 판단된다. 농업배수의 부하량에 따른 처리효율 결과 COD는 농업배수 부하량 600 L m-2 day-1까지 안정적인 처리효율을 보였으나, T-N 및 T-P는 150 L m-2 day-1≒300 L m-2 day-1¤600 L m-2 day-1의 순으로 농업배수의 부하량이 증가함에 따라 약간 감소하는 경향이었다. 따라서 시설하우스 농업배수 처리를 위한 인공습지 농업배수처리장의 최적조건은 HF-VH-HF 조합형 인공습지에 왕사, 쇄석 및 방해석이 혼합된 혼합여재로 충진하고 부하량 300 L m-2 day-1 이하의 농업배수를 주입하는 것이 최적일 것으로 판단된다.

연구는 당근-녹비 윤작지에서 헤어리베치 및 클림손클로버의 토양환원이 당근의 수량 및 토양의 물리․화학적 특성에 미치는 영향을 조사하였다. 당근재배지에서 전작물로 재배된 녹비작물의 질소(N), 인(P2O5), 칼륨(K2O), 칼슘(CaO) 및 마그네슘(MgO) 공급량은 헤어리베치의 경우 각각 23.8, 12.8, 6.1, 1.7, 및 2.8 kg 10a-1이었으며, 클림손클로버의 경우 각각 4.3, 6.0, 3.5, 1.3, 및 1.3 kg 10a-1이었다. 당근재배지에서 녹비작물의 토양환원 후 토양의 이화학적 특성을 조사한 결과 가밀도는 녹비작물 처리구가 대조구에 비해 감소하였고, 공극율은 증가하였다. EC는 녹비작물 처리구가 대조구에 비해 약간 낮았으며, 유기물, T-N 및 avail. P2O5는 대조구에 비해 높았다. 당근의 장해율은 녹비작물 처리구가 대조구에 비해 감소하는 경향이었고, 장해된 당근의 수량을 제외한 상품수량은 헤어리베치 처리구 (3,733kg 10a-1)가 대조구(2,566kg 10a-1)에 비해 45.5%의 증수효과를 보였다. 따라서 당근재배지에서 녹비작물의 시용은 비료로서 충분한 가치가 있으며, 녹비작물 토양환원 후 토양의 물리성 및 화학성을 개선함으로써 당근의 상품수량을 증대시킬 수 있을 것으로 판단된다.

This pot experiment was conducted to find out the forage productivity and quality in a grasslclover sward as affected by the application of three different fertilizers; double superphosphate(DS), fused Mg-phosphate (FP), and complex fertilizer(CF) on newl

신개간 산지초지(山地草地)의 정착(定着), 목초(牧草)의 수량제고(收量提高)및 품질향상(品質向上)등에 미치는 초지조성비(草地造成肥) 비종(肥種)별 시비효과를 비교검토하여 초지(草地)의 합리적인 시비개선(施肥改善)에 기여하고자 하였다. 미개간 산지토양(山地土壤)의 표토(表土)를 공시(배지)하여 orchardgrass와 ladino clover를 혼파(混播)한 pot 시험으로 기초실험을 수행하였다. 공시(供試)된 초지조성비(草地造成肥) 비료(肥料)의 처리내용은 1 ) 무비구, 2) 요소-중과석-염가, 3) 요소-용성인비-염가 및 4) 3종복비 ( N − P 2 O 5 K 2 O − M g O − B 2 O 3 − O M : 6-18-5-3-0.2-10)이였다. 본보(本報)에서는 건물수량(乾物收量), 수량(收量) 구성요소(構成要素) 및 식생(植生) 구성비율(構成比率)의 변화를 검토하였다. 1. 혼파목초(混播牧草) 및 ladino clover의 건물수량(乾物收量)은 3종복비>용인>중과석 시비구 순으로 높았고, 이들간 큰 차이를 보였다. 중과석 시비구의 각 구성목초(構成牧草)의 수량(收量)을 100%로 한 상대수량(相對收量)을 다른 시비구와 비교하여 보면, 용인 시비구에서는 혼파목초(混播牧草) 25.4%, ladino clover 21.7% 및 orchardgrass 34.2%의 수량증수(收量增收)를 보였다. 그리고 3종복비 시비구에서는 혼파목초(混播牧草) 50.4%, ladino clover 69.7% 및 orchardgrass 28.4%의 수량증수(收量增收)를 보였다. 미본과목초(未本科牧草)인 orchardgrass의 수량(收量)은 중과석구에서 가장 낮았으며, 수량성(收量性)이 높은 용인 및 복비구간은 유의성(有意性)이 없었다. 2. 식생(植生) 구성비율(構成比率)을 보면, 중과석과 용인 시비구에서는 orchardgrass : ladino clover의 비율은 약 1:1 (48:52%) 수준을 보였으나, 3종복비 시비구에서는 2:3(40:60%) 수준을 보였다. 신개간 산지토양(山地土壤)에서 초지조성비(草地造成肥)로 공시된 3종복비의 수량(收量) 중수효과가 가장 높았으며, 특히 두과목초(荳科牧草)인 ladino clover의 정착(定着), 수량성(收量性)및 식생(植生) 구성비율(構成比率)의 향상에 미치는 효과가 높았다.

This study was carried out to evaluate the pollutant removal efficiencies of the advanced drinking water treatment using ozonation process. For raw water, Nakdong River was used. By conducting batch test of ozonation, the following results were obtained. When ozone dosage of 5 mg/ℓ was used, ozone transfer and utilization efficiencies of the ozonation were 94 to 92%, respectively. Removal efficiencies of single VOC compound or mixed VOC compounds in the raw water were 80% to 90% by the ozonation with 2 mg/ℓ dosage and 10 minutes contact time. Removal efficiencies of ABS by the ozonation with 1 mg/ℓ, 3 mg/ℓ dosage and 20 minutes contact time were 83% to 96% , respectively. Almost 67% of chlorophyll-a at the concentration of 38.4㎍/ℓ was removed by ozonation at ozone dosage of 1 ㎎/ℓ for 20 min. Considering the efficiency of ozone utilization and water treatment, the most effective ozonation could be obtained with high ozone dosage and short contact time.

This study was carried out to evaluate the pollutant removal efficiencies of the advanced drinking water treatment using ozonation. For raw water, Nakdong River was used. By conducting batch ozonation test, the following results were obtained. When ozone dosage of 5㎎/ℓ was used, preozonation of raw water reduced turbidity, KMnO4 consumption, DOC(dissolved organic carbon), UV254 absorbance, THMFP(trihalomethane formation potential) as much as 3.9 NTU, 5.5㎎/ℓ, 1.15㎎/ℓ, 0.112 and 0.065㎎/ℓ, respectively. In case of postozonation of sand filtered water, water quality was also improved with decrease in turbidity, KMnO4 consumption, DOC, UV254 absorbance and THMFP at the amount of 0.08NTU, 2.6㎎/ℓ, 0.88㎎/ℓ, 0.042 and 0.018㎎/ℓ, respectively. On the other hand, contents of dissolved oxygen increased at the level of 1.3㎎/ℓ after preozonation process' and 1.0㎎/ℓ after postozonation process. The effect of ozone dosage was higher than that of its contact time for the removal of the pollutants.

약용작물은 재배 환경이나 재배 년수, 생육 시기, 부위별로 약리성분 함량에 차이가 많은데, 본 연구에서 해독, 소종, 소변불리, 간염, 황달 등의 치료에 효과가 있는 삼백초를 퇴비시용량과 재배방법을 달리하여 생육상황, 수량 및 유효성분 함량을 분석한 결과는 다음과 같다. 삼백초는 퇴비 시용량이 증가할수록 지상부 생체수량이 높았으며, 유효성분으로 quercetin, quercitrin 및 tannin 함량을 분석한 결과 퇴비 2,000kg/10a 처리시 가장 높았다. 예취 회수별 지상부 수량은 년 1회와 2회 수확간 차이가 없었으며, 유효성분 함량은 년 2회 수확하였을 때 7월 16일에 비해 10월 16일 수확시 함량이 높았다. 재배방법별로는 노지재배시 하우스재배에 비해 지상부 생체수량은 낮았지만 quercetin, quercitrin 및 tannin 함량은 높았다.

약용작물은 재배 환경이나 재배 년수, 생육시기 , 부위별로 약리성분 함량에 차이가 많은데, 본 연구에서 해독, 소종, 소변불리, 간염, 황달등의 치료에 효과가 있는 삼백초를 생육 시기별 및 부위별로 유효성분 함량을 분석한 결과는 다음과 같다. 생육 시기별 quercetin, quercitrin 및 tannin 함량은 생육초기에 가장 높았으며, 개화기 전까지 감소하다가 개화기 이후로 약간 증가 하였다. 7월 26일 수확했을 때 quercetin, quercitrin 및 tannin함량은 각각 5.72, 5.45g/kg 및 1.5%였다. 부위별 유효성분을 분석 한 결과 quercetin은 횐잎에서 함량이 가장 높았고, quercitrin은 잎에서 가장 높았으며, tannin은 꽃에서 가장 높았다. 부위별 무기성분 함량은 꽃에서 K, Ca, Mg, Cu, Zn의 함량이 가장 많았고, 횐잎에서는 K, Zn의 함량이 비교적 많았으며, 잎에서는 Fe가 가장 많았고 뿌리 에서 는 Na가 가장 많았다.

This study was performed to determine the optimum coagulant dosing for effective treatment of raw water in Chinyang lake. Removal rates of algae and characteristics of the water according to coagulants dosage were investigated by treatment with Microcystis aeruginosa, which is a kind of blue-green algae, to the raw water below 5NTU. The coagulants dosage for maximum removal rate of algae were 30 ㎎/ℓ of Alum, 30 ㎎/ℓ of PAC and 10 ㎎/ℓ of PACS, respectively. The removal rate of algae in 30 ㎎/ℓ of PAC was highest as 85% compared with the other treatments. At the point of maximum removal rate of algae, the removal rates of turbidity were 34%, 66% and 22% in Alum, PAC and PACS, respectively. Residual Al was decreased depend upon decreasing turbidity in water by treatment of Alum or PAC, but decreased depend upon increasing turbidity in water by treatment of PACS. The removal rate of Mn2+ in water was high in the order of Alum, PAC and PACS treatment. And Fe2+ in water was not changed by treatment of these coagulants. Particle numbers distributions according to the particle size of suspended solids that were not precipitated at 8 min. of settling time after treatment of coagulants dosage for the maximum removal rate of algae were investigated. Most of the particle sizes were below 30 ㎛ and particle numbers distributions below 10 ㎛ were 64%, 56% and 66% by treatment of Alum, PAC and PACS, respectively. Zeta potential was in the range of -6.1∼-9.7 mV at optimum coagulants dosage for algae removal.

The sewage sludges and livestock manures, respectively, were composted with sawdust used for control moisture in the static piles system composter. The variations of temperature, pH, moisture, C/N ratio, inorganic content, forms of organic materials and nitrogen, and contents of heavy metals were investigated. The results were summarized as follows ; The temperature for composting the sewage sludges reached the highest temperature of 52℃, after 3 days and lasted for 7 days, and then went down 30℃ after 52 days. In the case of composting livestock manures, the temperature reached to 63℃ after 10 days, that lasted for 10 days, and then went down gradually. After upsetting the sewage sludges and livestock manures, the temperature went up but was little changed after 52 days. Thus we decided that the terminal of composting periods would be 52 days. The moisture contents of the sludges and livestock manures for composting were decreased to 30% and 36%, respectively. The contents of inorganic matters and heavy metals were changed by the characteristics of raw materials but increased gradually during composting process. The total contents of organic materials in the sewage sludges and livestock manures for composting were decreased to 7% and 9%, respectively. The contents of ether extracts, resins, hemicellulose and cellulose were decreased but those of water soluble polysaccharides and lignins were not changed. The total contents of nitrogen in sewage sludges and livestock manures were decreased to 43% and 34%, respectively.

This study was performed to determine the optimum coagulant dosing amount for effective treatment of raw water. The removal rate of turbidity and the variations of water qualities according to various dosage of coagulants such as Alum, PAC and PACS were investigated. The optimum coagulant dosing amount to make the lowest turbidity of water were 35㎎/ℓ of Alum, 30㎎/ℓ of PAC and l0㎎/ℓ of PACS in case of 5 NTU of raw water turbidity, and 30㎎/ℓ of Alum, 25㎎/ℓ of PAC and l0㎎/ℓ of PACS in case of 10 NTU of that, respectively. The removal rates of turbidity at 4 min. and 8 min. of settling time were 10 and 72% of Alum, 44 and 62% of PAC and 25 and 55% of PACS in case of 5 NTU, and 52 and 70% of Alum, 90 and 95% of PAC and 10 and 28% of PACS in case of 10 NTU, respectively. Judging from the settling capability of floc., the reaction time of floc. formation and removal efficiency of turbidity, PAC was evaluated as more effective coagulant than Alum and PACS. Also PAC was regarded as the most effective coagulant when the water supply was changed sharply and the fluctuation of the surface loading occured with wide and sharp in seettling basin. pH and alkalinity of the water were decreased with increasing coagulants dosage. But pH and alkalinity were not decreased below 5.8 which is the standard for drinking water quality, and l0㎎/ℓ which is the limit concentration of floc. breakage, respectively. Residual Al of the treated water was decreased with increasing coagulants dosage in case of 5 and 10NTU of raw water turbidity. KMnO_4 consumption of the water was decreased with increasing coagulants dosage. The reduction rate of KMnO_4 consumption at the optimum coagulants dosage were 39% of Alum, 18% of PAC and 11% of PACS in case of 5 NTU of raw water turbidity, and 42% of Alum, 27% of PAC and 36% of PACS in case of 10 NTU of that, respectively. Any relationship was not found between the removal rate of turbidity and KMnO_4 consumption. TOC of the water was a bit decreased with increasing coagulants dosage up to 30㎎/ℓ but not changed above 30㎎/ℓ of coagulants dosage. The degree of TOC reduction was increased in the order of Alum, PAC and PACS treatment. Zeta potential of the colloidal floc. at the optimum coagulants dosage was in the range of -20∼-15mV in case of 5 NTU of raw water turbidity and 0∼0.5mV in case of 10 NTU of that, respectively. Although the kinds and dosages of coagulants were different, zeta potential range were fixed under the conditions of the best coagulation efficiency.

To examine water pollution status of agricultural water source of greenhouse area in Gyeongnam, the ground water quality was investigated six times at five areas in Gyeongnam from October in 1995 to March in 1996. pH of ground water were generally in the range of 5.9∼7.6. But a site in Changnyeong area was out of the range in 6.0∼8.5 which is water quality standard for agriculture. COD of ground water was below 8.0㎎/ℓ which is water quality standard for agriculture in all areas and the average was below 2.8㎎/ℓ. NH_4^+ -N contents in ground water was very low in all areas and the average of NO_3^- -N contents in Changnyeong and Chinju area was high with 13.2 and 11.5㎎/ℓ, respectively. Hardness, SO_4^2- and EC of ground water in Haman were higher than any other area. Fe and Mn contents of ground water in Kimhae were higher than any other area with 7.17 and 0. 95㎎/ℓ, respectively. Heavy metals such as Cu, Cd, Pb and Zn of ground water were below water quality standard for agriculture but some sites were over. Between COD and SS in ground water were not correlated with r=0.328, but between COD and NH_4^+ -N were positively correlated. And EC was positively correlated with Ca^2+, Mg^2+ and SO_4^2-. Ground water pollution status of agricultural water source of greenhouse area in Gyeongnam was generally high in order of Sacheon < Chinju < Haman < Kimhae < Changnyeong.

To study the optimum conditions of composting with industrial wastewater sludge, the variations of temperature and CO_2 generation amount during the composting periods were investigated. The conditions were that industrial wastewater added to bulking agents such as sawdust and rice hull was used, and differently treated with microorganism seeding or not, initial C/N ratios, air flow rate and initial moisture contents, respectively. The results were summarized as follows ; Seeding 5% of microorganism was higher the temperature than not seeding. And using sawdust as bulking agents, and adjusting 30∼40 of initial C/N ratio, 200㎎/ℓ·min. of air flow rate and 67∼68% of initial moisture contents were higher the temperature than any other conditions. Seeding 5% of microorganisms was higher CO_2 generation amount than not seeding. And that was much in the order of 7∼40, 30∼34 and 22∼23 of initial C/N ratio. Judging from the results, it should be considered that the optimum conditions in the composting of industrial wastewater sludge were seeding of 5% microorganisms, and adjusting 30∼34 of initial C/N ratio, 200㎎/ℓ·min. of air flow rate and 67∼68% of initial moisture contents. The contents of inorganic matters and C/N ratio during the composting periods at optimum condition were a little increased, and heavy metals contents after composting were lower than standard for fertilizer.

Chemical characteristics of the industrial wastewater sludge, degradation of the sludge in soil and CO2 generation and changes of nitrogen in soil treated with the sludge were investigated. The results obtained were summarized as follows: 1. Degradation rate of the sludge in soil was 26% at natural temperature, and 33% at incubation temperature at 12 weeks after treatment. 2. T-C, T-N and the C/N ratio of sludge in soil was 16.0%, 0.63% and 26, respectively, at natural temperature, and 15.0%, 0.65% and 23, respectively, at incubation temperature at 12 weeks after treatment. 3. Camulative CO2 generation in soil treated with 1%, 3% and 5% of sludge was 284, 440 and 512 ㎎/100g, respectively, at natural temperature, and 440, 558 g and 654 ㎎/100 g, respectively, at incubation temperature at 12 weeks after treatment. 4. Changes of inorganic nitrogen in soil treated with 1%, 3% and 5% of sludge were 7.8, 12.8 and 16.3 ㎎/100g, respectively, at incubation temperature at 12 weeks after treatment. Mineralization ratio of organic nitrogen in soil treated with 1%, 3% and 5% of sludge was 10.7%, 13.6% and 15.2%, respectively, at incubation temperature at 12 weeks after treatment. 5. Changes of pH in soil treated with 1%, 3% and 5% of Industrial wastewater sludge were in the range of 6.7∼7.5 at natural temperature, and 6.1∼7.9 at incubation temperature at 12 weeks after treatment.

This study was performed to develop the biological treatment technology of wastewater polluted with heavy metals. Zinc-tolerant microorganism, such as Pseudomonas chlororaphis which possessed the ability to accumulate zinc, was isolated from industrial wastewaters polluted with various heavy metals. The characteristics of zinc accumulation in the cells, recovery of the zinc from the cells accumulating zinc, were investigated. Removal rate of zinc from the solution containing 100 ㎎/ℓ of zinc by zinc-tolerant microorganism was more than 90% at 48 hours after inoculation of the microorganisms. A large number of the electron-dense granules were found mainly on the cell wall and membrane fractions, when determined by transmission electron microscope. Energy dispersive X-ray spectroscopy revealed that the electron-dense granules were zinc complex with the substances binding heavy metals. The zinc accumulated into cells was not desorbed by distilled water, but more than 80% of the zinc accumulated was desorbed by 0.1M-EDTA. The residues of the cells after combustion at 550℃ amounted to about 21% of the dry weight of the cells. EDS analysis showed that the residues were comparatively pure zinc compounds containing more than 79% of zinc.