양이온교환용량이 다른 제올라이트 처리에 따른 밭토양 내 중금속 안정화 평가

구본운,김문주,박성직,Gu, Bon-Wun,Kim, Mun-Ju,Park, Seong-Jik 한국농공학회 2017 한국농공학회논문집 Vol.59 No.5

This study was aimed to investigate the influence of cation exchange capacity (CEC) and application amounts of zeolite on the stabilization of heavy metals (As, Ni, Pb, and Zn) in upland soils. The upland soils were sampled from field near mines located in Gyeonggi Province. The CEC of zeolite was treated at three different levels, ie, low, medium, and high, while zeolite was amended with soils at the ratio of 0.1 % and 0.5 % as to soil weight. A sequential extraction was performed for the soil sampled at 1, 2 4, and 8 week after zeolite was added to the soil. The concentrations of Pb and Zn appeared to be high in the sampled soils. The mobility of heavy metals obtained from sequential experiments was as follows: Pb > Zn > Ni >As. Addition of zeolite to contaminated soils effectively reduced exchangeable and carbonate fractions but increased organic and residual fraction, indicating that zeolite is effective for immobilizing heavy metals in soils. The influence of incubation time on the metal stabilization was rather pronounced as compared to the application amount and CEC of zeolite.

용인과 안성 지역의 유기논 및 관행논에서 토양 화학 특성 및 중금속 함량 비교

구본운,이태구,강구,홍성구,홍승길,장태일,김진호,박성직,Gu, Bon-Wun,Lee, Tae-Gu,Kang, Ku,Hong, Seong-Gu,Hong, Seung-Gil,Jang, Tae-Il,Kim, Jin-Ho,Park, Seong-Jik 한국농공학회 2017 한국농공학회논문집 Vol.59 No.3

The aim of this study is to investigate the chemical properties and heavy metal concentration of soils in conventional and organic paddy. We sampled and analyzed topsoil (0~15 cm) and subsoil (15~30 cm) of conventional and organic paddy fields in Yongin and Anseong, South Korea. The statistical significance between groups was determined by Duncan's multiple range test and correlation between soil properties was also analyzed. The results show that organic matter (OM) and T-N of conventional paddy soil were higher than those of organic paddy soil. However, higher T-P concentration was observed in organic paddy soil than conventional paddy soil. As, Pb, and Zn concentration in organic paddy soil were statistically lower than those in conventional paddy soil. The couple of water content (WC) & As, OM & T-N, T-P & $P_2O_5$, T-P & Zn, $P_2O_5$ & Zn, and Cr & Ni had a good positive correlation but the couple of WC & T-P, WC & Zn, T-P & As, and As & Zn had a strong negative correlation. It can be concluded that organic farming is beneficial to soil environment by reducing the amounts of organic matter, T-N, As, Pb, and Zn concentration in paddy soil when compared to conventional farming.

Cr(VI) 제거를 위한 철피복 Vermiculite의 합성

구본운,박성직 대한환경공학회 2016 대한환경공학회 학술발표논문집 Vol.2016 No.11

유기논 및 관행논에서 토양 내 중금속 특성 비교

구본운 ( Bon-wun Gu ),강구 ( Ku Kang ),박성직 ( Seong-jik Park ) 한국농공학회 2016 한국농공학회 학술대회초록집 Vol.2016 No.-

유기 농업은 농업생태계의 다양성과 지속 가능한 농업 생산을 위한 대안 농법으로 인식되었다. 그러나 유기농법은 관행농법과 달리 유기질 비료만을 사용하므로 환경 친화적이며 화학 비료와 달리 다량을 사용하여도 해가 없다는 인식 때문에 과량의 유기물이 시용되고 왔다. 이로 인하여 유기 농업 토양의 염류집적과 작물 생산성 저하를 불러일으켰다는 유기농업에 대한 부정적인 연구 결과도 있다. 유기농업이 환경에 미치는 영향에 대한 연구 결과는 아직 논란이 많은 실정이다. 유기농업의 환경적 가치를 정확하게 평가하고 최적관리방안을 마련하기 위해서는 추가적인 연구가 필요한 실정이다. 본 연구에서는 논 토양의 유기농법 및 관행농법의 적용에 따른 토양 내 중금속 함량의 비교를 통해서 농법에 따른 토양 환경 특성을 비교 평가하였다. 본 연구에서는 유기 농업과 관행 농업을 수행하는 논에서의 토양 특성 비교를 위해서 유기논 23개 필지와 관행논 10개 필지를 선정하였다. 유기논은 용인시 원삼면 14개 필지, 안성시 고삼면 8개 필지, 안성시 대덕면 1개 필지를 선정하였다. 유기논의 토양 특성과의 비교를 위하여 유기논 인근에 위치한 관행논으로 용인시 원삼면 4개 필지, 안성시 보개면 6개 필지를 선정하였다. 중금속 총량은 풍건시료 1 g에 HNO3 0.5 mL, HF 5 mL, HCl 2 mL를 넣고 140℃에서 2시간 동안 분해 후 As, Cd, Cr, Cu, Ni, Pb, Zn 농도를 ICP-OES로 측정하였다. 조사결과, 유기논 및 관행논 토양의 As, Cd, Ni, Pb 및 Zn의 함량은 토양오염우려기준 이하로 존재하였고, 전국 답의 중금속 평균 함량 보다도 낮았다. 유기논 토양의 중금속 함량은 관행논에 비하여 낮았지만, Zn를 제외하고 통계학적 차이는 없는 것으로 나타났다. 따라서 유기논 토양이 관행논 토양에 비하여 중금속 농도 측면에서 그 차이는 크지 않지만 양호하다고 판단된다.

유기논 및 관행논에서 토양의 물리화학적 특성 비교

구본운 ( Bon-wun Gu ),박성직 ( Seong-jik Park ) 한국농공학회 2016 한국농공학회 학술대회초록집 Vol.2016 No.-

유기 농업은 화학비료와 농약으로 인해 직접 피해를 입은 생산자에 의해서 자발적으로 시작되었지만, 국가정책으로 친환경농업정책을 시행함에 따라서 보편화 되었다. 특히 삶의 질에 대한 관심이 높아짐에 따라서 보다 안전한 농산물의 수요 증대 및 환경에 대한 관심 증대로 인하여 유기농업이 외연적 확장을 이루었다. 유기농업은 농업생태계의 다양성과 지속 가능한 농업 생산을 위한 대안 농법으로 인식되고 있지만, 유기농법은 관행농법과 달리 유기질 비료만을 사용하므로 환경 친화적이며 화학 비료와 달리 다량을 사용하여도 해가 없다는 인식 때문에 과량의 유기물이 시용되었다. 또한 유기물의 과량 시용은 유기 농업 토양의 염류집적과 작물 생산성 저하를 불러일으켰다는 유기농업에 대한 부정적인 연구 결과도 있다. 반면에 유기농업은 잡초 성장에 의해서 관행논에 비하여 토양 유실량이 적고, 미생물의 활성을 촉진시킨다는 긍정적 연구 결과도 있다. 이러한 유기농업이 환경에 미치는 영향을 정량적으로 평가하고 환경에 미치는 긍정적 영향을 극대화 하기 위한 최적관리방안 마련을 위해서는 추가적인 연구가 필요하다. 본 연구에서는 논 토양의 유기농법 및 관행농법의 적용에 따른 토양의 물리화학적 특성 비교를 위해서 용인과 안성지역의 유기논 23개 필지와 관행논 10개 필지의 토양을 채취 및 분석하였다. 조사 항목으로는 토양의 건조밀도, pH, EC, 그리고 유기물 함량을 분석하였다. 토양의 입도 분석은 ASTM D422에 따라서 표준체 4번부터 200번까지 체분석을 실시하였고, 200번 체를 통과한 시료는 비중계 분석법을 적용하였다. pH는 토양과 증류수 비율 1:5로 하여 1시간 교반 후에, EC 역시 토양과 증류수 비율을 1:5로 하고 30분 교반 후 No. 2여과지로 여과 후 pH 및 EC meter를 이용하여 측정하였다. 유기물함량은 작열 손실량법으로 450 °C에서 2시간 가열 후 측정하였다. 조사 결과 유기논 토양의 건조밀도는 관행논에 비하여 높게 나타났고, pH의 경우는 유기논과 관행논 사이에 통계적 차이는 없었다. EC 값을 비교한 결과 유기논의 EC 보다 관행논에서 높게 나타나, 유기농업 토양에서 염류집적이 발생하였다는 기존문헌과 상반된다. 유기물함량은 관행논에서 유기논 보다 높게 나타났다.

Fe 피복 vermiculite를 이용한 수용액상에서 Cr(VI)의 제거

구본운 ( Bon Wun Gu ),박성직 ( Seong Jik Park ) 한국수처리학회 2016 한국수처리학회지 Vol.24 No.4

We synthesized Fe-coated vermiculite (Fe-CV) for the removal of Cr(VI) and investigated the mechanism of Cr(VI) adsorption onto Fe-CV. Fe-CV was synthesized at different Fe molar concentration to vermiculite ratio, i.e., 1, 2, 5, 8, 10 mol-Fe/kg. Fe-CV synthesized at 8 mol-Fe/kg was found to be most effective for the removal of Cr(VI) and further experiments were performed under batch condition using the Fe-CV. Kinetic sorption test and model analysis showed that observed data were well suited to pseudo second-order model, indicating that chemisorption dominates the process of Cr(VI) adsorption to Fe-CV. Equilibrium test demonstrated that Freundlich model well describes Cr(VI) adsorption to Fe-CV and the maximum Cr(VI) adsorption capacity of Fe-CV was 6.86 mg/g. Cr(VI) removal was the highest at pH 2 and decreased with increasing pH due to electrostatic repulsion between Cr(VI) and Fe-CV at higher pH. The effect of competing anions on Cr(VI) adsorption follows the order: PO₄^3->Co₃^2->So₄^2->NO₃^-. The removal percentage of Cr(VI) was increased but the adsorbed amount of Cr(VI) per unit mass of Fe-CV was decreased as the increase of the dosage amount of Fe-CV. Finally, Fe-CV is an effective adsorbent for the removal of Cr(VI) and the results of this study are helpful for understanding the mechanism of Cr(VI) removal by Fe-CV.

열처리된 폐콘크리트를 이용한 인 제거 및 동역학적 칼럼 모델 적용

구본운 ( Bon-wun Gu ),박성직 ( Seong-jik Park ) 한국수처리학회 2017 한국수처리학회지 Vol.25 No.1

In this study, we investigated the removal of P in aqueous solution using thermally treated crushed concrete under dynamic flow condition. Column experiments were performed in step injection mode under various conditions of influent P concentration (2.0-4.0 mg/L), flow rate (0.4-1.0 mL/min), and column length (5-15 cm). The breakthrough curves (BTCs) obtained from column experiments were fitted to Adams-Bohart, Thomas, Yoon-Nelson, and Dose-response kinetic models. The highest column capacity for P removal (q0) of 3.085 mg/g and removal percentage (Re) of 66.4% were achieved using an influent P concentration of 3.0 mg/L, flow rate of 0.4 mL/min, and column length of 10 cm. Increasing the P concentration and flow rate had a negative effect on Re, whereas the increase of column length was positively affected. Increasing flow rate and column length produced a negative effect on q0. The flow rate in the range of this study influenced on the performance of column more significantly than other two factors. Adams-Bohart model adequately fitted to the initial part of the BTCs, whereas the Thomas and Yoon-Nelson models were appropriate for describing the transient stage of the BTCs between the breakthrough point and saturation point. Theoretical q0 obtained from Thomas model and time required for 50% breakthrough of P (τ) obtained from Yoon-Nelson model were very close to experimental values. This study demonstrates the adequate performance of thermally treated crushed concrete as a filter material for the removal of P from aqueous solutions

유기논 및 관행논에서 시비에 따른 담수 수질 및 토양 특성

구본운 ( Bon-wun Gu ),박성직 ( Seong-jik Park ) 한국수처리학회 2016 한국수처리학회지 Vol.24 No.5

The aim of this study is to investigate the ponded water quality of conventional paddy and organic paddy at different fertilization times. Water and soil were sampled and analyzed two times, after basal fertilization (May 2015) and after additional fertilization (August 2015). The statistical significance between groups was determined by Duncan`s multiple range test. The results show that pH, COD, and SS of ponded water were not statistically dependent on fertilization timing and farming methods. EC of ponded water in conventional paddy after additional fertilization was higher than that of organic paddy, and higher BOD was observed after additional fertilization than after basal fertilization. In contrast to T-N, NH₄-N, and NO₂-N, fertilization timing statistically influenced on NO₃-N, T-P and PO₄-P. T-P and PO₄-P concentrations of ponded water in organic and conventional paddy were also different depending on the farming method. Soils in conventional and organic paddy were also sampled and analyzed to compare them with water quality data. pH and EC of paddy soil were not statistically dependent on fertilization timing and farming methods. Higher OM content was observed in conventional paddy than organic paddy. Although T-N, NH₄-N, and NO₃-N of ponded water were not dependent on fertilization timing, their amounts in soils were varied with fertilization timing. T-P in soil was higher after additional fertilization than after basal fertilization and vice versa, P₂O₅ was higher after basal fertilization. It can be concluded that fertilization timing influenced on ponded water quality more than farming methods.

폐콘크리트를 이용한 수중 불소의 제거 및 흡착 특성

구본운 ( Bon Wun Gu ),강구 ( Ku Kang ),박성직 ( Seong Jik Park ) 한국수처리학회 2015 한국수처리학회지 Vol.23 No.6

Crushed concrete was used for the removal of fluoride from aqueous solution and its adsorption characteristics were investigated. Adsorption experiments have been conducted in batch conditions. From the experiments using crushed concrete thermally treated at different temperatures, it was found that thermal treatment on crushed concrete had a deleterious effect on the fluoride removal. Kinetic sorption test and model analysis showed that fluoride adsorption to crushed concrete was dependent on chemisorption. Equilibrium adsorption results followed the Langmuir adsorption isotherm model with adsorption capacity of 28.50 mg/g. The estimated thermodynamic parameters (ΔH°, ΔS° and ΔG°) indicated that the adsorption was spontaneous and endothermic. Additional batch experiments indicated that fluoride adsorption to crushed concrete was the highest at pH 3 and decreased with increasing pH. The effect of other anion on fluoride removal by crushed concrete followed the order of PO4^3- > HCO3- > SO4^2- □ NO3-. This study demonstrated that crushed concrete was proven to be an effective adsorbent with high adsorption capacity of fluoride and its use for the fluoride removal is economical and environmentally sustainable.

부직포 매트의 공극 크기가 오염퇴적물로부터 유기물 및 영양물질의 용출 차단에 미치는 영향 분석

구본운 ( Bon-wun Gu ),홍승희 ( Seung-hee Hong ),박성직 ( Seong-jik Park ) 한국수처리학회(구 한국수처리기술연구회) 2017 한국수처리학회지 Vol.25 No.4

The aim of this study is to evaluate the applicability of non-woven fabric mats (NWFMs) for interrupting organic matters and nutrients from contaminated reservoir sediments and investigate the pore size of NWFMs on its blocking efficiency. In laboratory incubation experiments, environmental conditions (pH, electric conductivity, dissolved oxygen (DO), and oxidation reduction potential) and contaminant concentrations (T-N, NH₄-N, NO₂-N, NO₃-N, T-P, and PO₄-P) were monitored. DO in uncapped condition was exhausted within four days but the DO in NWFM capping was prolonged for more than 22 days. Lower concentration of COD was observed in the NWFMs capping than uncapped, indicating that the NWFMs were effective for interrupting organic matter release. T-N was mainly composed of NH₄-N and NH4-N release was effectively blocked by NWFMs capping. NWFMs capping was effective for interrupting not soluble phosphorus but adsorbed phosphorus release. NWFMs with smaller pore size was effective for blocking the release of T-P and COD than NWFMs with larger pore size, but the influence of pore size on T-N was not significant. It can be concluded that NWFM can be successfully used for remediation of reservoir`s sediments with high amounts of organic matters and nutrients.