Excess nitrogen (N) flowing from livestock manure to water systems poses a serious threat to the natural environment. Thus, livestock wastewater management has recently drawn attention to this related field. This study first attempted to obtain the optimal conditions for the further volatilization of NH3 gas generated from pig wastewater by adjusting the amount of injected magnesia (MgO). At 0.8 wt.% of MgO (by pig wastewater weight), the volatility rate of NH3 increased to 75.5% after a day of aeration compared to untreated samples (pig wastewater itself). This phenomenon was attributed to increases in the pH of pig wastewater as MgO dissolved in it, increasing the volatilization efficiency of NH3. The initial pH of pig wastewater was 8.4, and the pH was 9.2 when MgO was added up to 0.8 wt.%. Second, the residual ammonia nitrogen (NH4 +-N) in pig wastewater was removed by precipitation in the form of struvite (NH4MgPO4·6H2O) by adjusting the pH after adding MgO and H3PO4. Struvite produced in the pig wastewater was identified by field emission scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD) analysis. White precipitates began to form at pH 6, and the higher the pH, the lower the concentration of NH4 +-N in pig wastewater. Of the total 86.1% of NH4 +-N removed, 62.4% was achieved at pH 6, which was the highest removal rate. Furthermore, how struvite changes with pH was investigated. Under conditions of pH 11 or higher, the synthesized struvite was completely decomposed. The yield of struvite in the precipitate was determined to be between 68% and 84% through a variety of analyses.

최근 웰빙 시대를 맞이하여 먹거리에 관심이 높아짐에 따라 과수나 작물에 대한 친환경 재배의 중요성이 증대되고 있다. 페로몬은 생물농약 중 생화학 농약으로 분류되는 친환경농자재로서 친환경농업을 위한 필수적인 해충 방제수단이다. 1959년 Butenent 등이 누에의 성페로몬 (E,Z)-10, 12-hexadecadienol을 최초로 보고한 이래 지금까지 수천 종의 곤충 페로몬이 보고되었다. 페로몬은 대부분 둘 또는 그 이상의 복합성분으로 구성되어있다. 곤충의 통신수단인 페로몬이 산업적인 측면에서 해충을 방제하는 수단으로 이용될 수 있다. 예를 들면, 페로몬을 이용하여 해충을 유인함으로서 집단의 최초 발생 시기, 개체군의 밀도 등을 예찰하여 살충제 투약 시기를 조절할 수 있으며, 혹은 직접적인 방제 목적으로 포획용 페로몬 덫을 응용할 수도 있다. 또 다른 응용으로 페로몬의 농도를 높여 자연에서 암수가 만나는 교미를 교란함으로서 2세대 이후의 개체 밀도를 줄일 수 있다. 페로몬이 해충방제 수단으로 수요 농가에 보급되어 화학농약을 대체하기 위해서는 몇 가지 필수적인 조건이 충족되어야 한다. 첫째 : 해충 유인력이 우수해야 한다. 따라서 95% 이상의 순도가 요구된다. 둘째 : 페로몬을 안정하게 지속적으로 휘발시킬 수 있는 적당한 담채 혹은 루어가 개발되어야 한다. 셋째 : 수요에 따른 대량 합성이 가능해야 하며, 적절한 합성단가를 유지해야 한다. 현재 합성법이 개발되어 우리나라 농가에 보급되고 있는 페로몬은 톱다리개미허리 노린재페로몬 등 10여종이며, 이미 개발되었거나 개발 중인 것은 은무늬굴나방페로몬 등 20여종이다. 페로몬은 천연물 중 그 구조가 대체로 간단하기 때문에 의약품 등과 비교하여 합성법을 개발하는 것이 어렵지 않다.

경북 안동지역의 10개 하천 및 하천 주변으로부터 2004년 5월에 물, 토양, 퇴적물의 시료를 채취하였다. 이들 지역의 환경오염 수준을 평가하기 위해 표준공정시험법이나 U.S. EPA 법을 이용하여 시료 중의 총질소, 총인, 화학적 산소요구량, 중금속, 유기인 및 유기염소계 잔류농약, 그리고 dioxin-like PCBs 등의 오염물질의 분석을 실시하였으며, 이와 더불어 파밤나방(Spodoptera exigua)을 이용한 면역교란의 생체지표 분석을 병행하였다. 일반적으로 총질소가 9.12 mg/L 수준의 와야천을 제외하고는, 각 하천 중의 총질소, 총인, 화학적 산소요구량은 환경부에서 정한 허용기준치보다는 비교적 낮았다. 각 하천 시료 중의 납과 카드뮴의 함량은 허용 기준보다도 매우 낮았지만, 하천에 따라 차이가 있어서 미천, 길안천, 현하천의 납과 카드뮴 함유량은 다른 하천의 시료들에 비해서 몇 배 이상 높게 검출되었다. 잔류농약은 미천 주변의 토양에서 유기인계 살충제인 다이아지논, 파라치온, 그리고 펜토에이트가 0.19, 0.40, 농도로 검출되었다. 반면에 내분비계 교란물질로 알려져 있는 16종의 유기염소계 농약과 12종의 dioxin-like PCB congeners는 검출한계 미만으로는 확인할 수 없었다. 그러나 와야천의 시료에 대한 곤충면역 교란효과를 고려해 볼 때, 이 하천의 수질과 주변의 토양이 조사한 오염원 이외의 화합물에 오염되어 있을 가능성을 제시해 준다. 이상의 분석 결과를 토대로 화학적 및 생물학적 검정 기술의 제약점과 상호 보완성이 기술되었다

The midge samples were undertaken at three streams, representing different surrounding environments, to investigate the contaminant exposure of midge. The content of heavy metals in midge collected in Singil stream were generally higher as a result of input to the industrial effluents with respect to other streams. Adsorption experiments were done to evaluate the possibility of removing contaminants from water with midge. Diazinon and heavy metals were contaminant target compounds in this study. The removal rate of diazinon in water by midge was 60-75%. In the case of Cu, the removal rate was reached around 90% at the lower initial concentration of 1.87 and 0.81 ppm rather than 4.25 ppm. The reduction of concentration of Cr and Cd according to the lapse of time was similar to the Cu, but their removal rates were shown 50% and 60-74%, respectively. The removal rate of Zn by midge represented relatively high level within the experimental condition. No change in concentration of Cr and As with time were occurred at all experimental conditions. It accounts for the fact that the reduction of Cr and As could not be achieved through the adsorption process, using midge.

Practical disposal of transformer insulation oil laden with PCBs (polychlorinated biphenyls) by a chemical treatment has been studied in field work. The transformer insulation oil containing PCBs was treated by the required amounts of PEG (polyethylene glycol) and KOH, along with different reaction conditions such as temperatures and times. The reaction of PEG with PCBs under basic condition produces arylpolyglycols, the products of nucleophilic aromatic substitution. Removal efficiencies of PCBs in insulation oil before and after chemical treatment were examined. The removal efficiency of PCBs was very low at lower temperatures of 25 and 50℃. Under the reaction condition of PEG 600/KOH/100℃/2hr, removal efficiency of PCBs was approximately 70%, showing completely removal of PCBs containing 7~9 chlorines on biphenyl frame which appear later than PCB IUPAC Number 183 (2,2',3,4,4',5',6-heptaCB) in retention time of GC/ECD. However, when increasing the reaction temperature and time to 150℃ and 4 hours, removal efficiency of PCBs reached 99.99% without any formation of PCDDS/PCDFs during the process. Such reaction conditions were verified by several official analytical institutions. In studying the reaction of PEG with PCBs, it confirmed that the process of chemical treatment led to less chlorinated PCBs through a stepwise process with the successive elimination of chlorines.

A practical and efficient disposal method for chemical dechlorination of PCBs (polychlorinated biphenyls) in transformer oil was evaluated. The transformer oil containing PCBs was treated by the PEG 600 (polyethylene glycol 600) and potassium hydroxide (KOH) along with different reaction temperatures(25, 50, 100 and 150oC) and times(30, 60, 240 and 480 min). The best disposal efficiency of PCBs in transformer oil was attained under the experimental conditions of PEG 600 (2.5 w/w%)/KOH (2.5 w/w%)/150oC/4 hrs, showing completely removal of all PCBs containing 3-9 chlorines on two rings of biphenyl. In studying the reaction of PEG/KOH with PCBs, it confirmed that the process led to less chlorinated PCBs through a stepwise process with the successive elimination of chlorines.

A comprehensive quality survey for heavy metals, organophosphorous and organochlorine residual pesticides, and coplanar PCBs in samples such as water, sediments and soils as well as spiders has been implemented. The samples were undertaken at nine stream sites and their vicinity in August 2006, representing different surrounding environments. The levels of PCBs were expressed as concentrations and WHO-TEFs. Among 12 coplanar PCBs as target compounds in this study, 2,3',4,4',5-PentaCB (IUPAC # 118) was the congener with the highest concentration. The total concentrations and TEF values of coplanar PCBs in Siheung stream sediment (heavy industrial complex site located in Ansan city) were 3915.50 pg/g and 0.8366 pg-TEQ/g on a dry weight basis, respectively. Such levels were around 40 times higher compared to sediment from Gapyung stream (green site located in the upper of Myunggi mountain). It is probably due to the direct input of PCBs from PCBs treatment materials. Organophosphorous (EPN, dementon-s-methyl, diazinon, parathion, and phenthoate) and organochlorine (alpha-BHC, aldrin, 4,4'-DDT, 4,4'-DDE, endosulfan alpha and etc.) pesticides were not detected above 5 ppb of detection limits. The concentrations of Cu and Cd in water and sediment samples from Siheung stream were 44.11 and 0.17 ug/㎖ and 713.42 ㎍/g and 3.73 ㎍/g, respectively, which contained 20～40 times higher concentrations than those from Gapyung stream. In addition to the water and sediment samples, the levels of heavy metals in spider from designated sampling sites were also determined. Heavy metals in spider collected near Siheung stream was appeared to be equivalent and/or a little higher levels with respect to other spiders. Furthermore, the ratio of relative heavy metals (Cu, Cd, and Pb) in spider from each stream site showed a correlation as similar as that of heavy metals in soil samples.

Photodegradation of endosulfan alpha, beta, and sulfate known as the most toxic substance among organochlorine pesticides by UV irradiation was studied at experimental conditions such as different pH aqueous solution and reaction time. The initial concentration of endosulfan alpha, beta, and sulfate in aqueous solution was 500 ppb, respectively. The experiment of photodegradation was conducted in a quartz reactor equipped with a low pressure mercury lamp (100 W, 240 nm). The samples were withdrawn from the photo reactor at intervals of 0, 10 min, 30 min, 1 hr, 2 hr, and 4 hr. Endosulfan sulfate was never hydrolyzed and photodegraded in wide range of pH. At pH 5 and reaction time (240 min), endosulfan alpha was photodegraded up to 67%. Both endosulfan alpha and beta were started to photodegrade at pH 6.5 with the lapse of time, resulting in approximately 99.9% and 87.2% of photodegradation efficiency, respectively. Furthermore, at pH 9, endosulfan alpha and beta was partially hydrolyzed and photodegraded to 99.5% at 120 min of reaction time. During the photolysis, any photo-products of endosulfan alpha, beta, and sulfate were not observed.

Samples of water, soil, and sediment were taken from 10 streams of Andong city in Gyeongbuk province in October 2004. To assess the degree of environmental pollution for each stream site, the chemical analyses of pollutants such as T-N, T-P, COD, heavy metal, organophosphorous and organochlorine pesticides, and dioxin-like PCB congeners were implemented using the standard process tests or the U. S. EPA methods. In addition, biological assessment using insect immune biomarkers was conducted on the same environmental samples to complement the chemical assessment. Except Waya stream (T-N; 2.91 mg/L, T-P; 0.16 mg/L, COD; 14.0 mg/L) with above the environmental quality standards, the T-P and COD concentrations of 9 sites are relatively low. The contents of Pb and Cd in samples taken from each stream were much lower than environmental quality standards. However, in comparison with soil samples of other streams, several times higher concentrations of Pb and Cd were found in locations at Mi, Gilan, Yeonha, and Waya stream sites. Dementon-S-methyl, diazinon, parathion, and phenthoate compounds among organophosphorous pesticides were detected as concentrations of ppb levels, respectively, from soil samples collected in the vicinity of Gilan, Mi, Norim, and Waya stream. On the other hand, 16 organochlorine pesticides and 12 dioxin-like PCB congeners selected in this study were not found in all samples. In particular, considering significant disrupting effects of Waya stream's samples on insect immune capacity, this stream seems to be contaminated with investigated and/or uninvestigated pollutants in this study.