The acenaphthene(ACE) or acenaphthylene(ACEL) is one of the most frequently found compound in polycyclic aromatic hydrocarbon (PAH)-contaminated soil. In this study, we make 10mg/L ACE or ACEL in ethanol which is the model washing solvent for contaminated soil. This was followed by Fenton treatment in which 0.2 or 0.3mL of 30% H2O2 and 0.2 ml of 0.5 M Fe2+ were added. The results showed more than 88 or 99% of ACE or ACEL removal efficiency, respectively. Additionally, we employed GC-MS to identify the main oxidation product generated by the optimized Fenton oxidation [i.e., ACE or ACEL degraded in to 21, 34 % 1,8-naphthalic anhydride(NAPAN), repectively]. It is expected that biodegradability of NAPAN is enhanced because NAPAN has three oxygens compared with ACE and ACEL. Therefore the results suggest that the hybrid treatment system (i.e., ethanol washing -Fenton oxidation treatment) can be effectively applied to remove ACE or ACEL from soil..

This study was aimed to investigate treatment feasibility of leachate from D landfill that is located in gyr대ungbuk. From the analytical results of leachate, organic and nonbiodegradable matters were contained in high concentration. Thus chemical treatment was introduced to degrade nonbiodegradable matters in pre or post biological process. Two types of Fenton oxidation were adapted in this study. The first one is pre treatment process before biological treatment. The second one is post treatment process after biological treatment. The optimal conditions of both treatment methods were investigated as follows. In case of pre treatment process, the optimal conditions appeared in Fe+2/H2O2(mmol/mmol): 0.1, H2O2/CODcr(mg/mg): 27.0, pH: 3 and reaction time: 2hrs. On the other hand, in case of post treatment process, the optimal conditions appeared in Fe2+(mmol/mmol): 0.14, H2O2/CODcr(mg/mg): 57.4, pH: 3 and reaction time: 1.25hrs. In the above optimal conditions, high COD removal was obtained in pre and post treatment process. Also it can expect that Fenton oxidation converted nonbiodegradable matters into biodegradable matters.

This paper presents applicability of Fenton oxidation to perchloroethylene(PCE) contaminated soil. The initial concentration of PCE was 187mg/kg and Fenton oxidation conditions were 1.0M H2O2 and 0.5M Fe2+. More than 97% of PCE decomposition and 98% of dechlorination were obtained within 5 hrs. It was found that the decomposition of PCE by Fenton oxidation was followed pseudo first order and its reaction coefficient was 0.78 hr-1. GC-MS and GC-ECD analysis of reaction intermediates confirmed only the presence of trichloroacetic acid(i.e., 1.0% of initial PCE concentration). Under Fenton oxidation conditions, it was proposed that PCE was decomposed not simultaneously but one by one.

Organic contaminants can be released into water environments due to chemical accidents and exist as dissolved and non-aqueous phase liquids (NAPL). Fenton oxidation was tested for bisphenol A and nitrobenzene as model organic contaminants in dissolved and NAPL states. Fenton oxidation was successfully applied for both of the dissolved and NAPL states of the two pollutants and the results indicated that a quick treatment was needed to reduce the risk from a chemical accidents instead of carrying out oxidation after the contaminants dissolve in water. A set of Fenton reactions were tested under seawater conditions because chemical accidents often occurs in the ocean. Chloride ions act as radical scavengers and inhibit Fenton oxidation. The reaction rate is inversely proportional to salt contents and the reduced reaction rate can be compensated by increasing the quantity of the oxidizing agents. The current study showes that Fenton oxidation could be applied as a quick treatments for organic contaminant in dissolved and NAPL state organic contaminants released as a result of leaks or chemical accidents.

고도산화공정(Advanced Oxidation Process, AOP) 중 하나인 펜톤 산화법은 과산화수소(H2O2)와 2가철 이온(Fe2+)이 반응하여 OH 라디칼을 생성함으로써, OH 라디칼의 강한 산화력으로 유기물을 분해하는 방법이다(Kim et al., 2016). 펜톤 산화는 다양한 유기물과의 높은 반응성을 지닌다는 점과 생물학적으로 분해가 어려운 물질을 산화·분해시켜 생물학적 처리가 가능하도록 한다는 등의 장점을 지니고 있다(Lee et al., 2003, Sung et al., 2006). 그러나, 펜톤 산화는 유기물과의 반응 후 펜톤 슬러지를 부산물로 다량 생성하기 때문에 발생된 슬러지를 처리하는 공정이 추가적으로 요구된다. 또한, 펜톤 슬러지는 다량의 난분해성 물질과 철염 등을 함유하고 있기 때문에 처리하는 방법이 까다롭다. 펜톤 슬러지는 주로 ‘매립’으로 처리하고 있으나 매립지 크기의 한계 및 수명 단축, 비싼 처리비용 등의 문제가 뒤따르기 때문에 이에 대한 대책이 필요한 실정이다. 본 연구에서는 펜톤 슬러지를 처리하는 방안으로 펜톤 산화용 철 촉매로의 재이용을 제안하였고, 크게 슬러지 용해, 슬러지 내 철 이온 전환, 철 촉매 실사용 단계로 나눠 연구를 진행하였다. 본 연구는 ‘D’ 산업용수센터에서 발생하는 RO 농축폐수를 펜톤 산화법으로 처리한 후 발생하는 펜톤 슬러지를 대상으로 실시하였다. 반고체 형태의 펜톤 슬러지에 산(acid)을 가하면 용해액 상태로 바뀌는데 이는 펜톤 슬러지 사용을 용이하게 만든다. 이에 pH, 반응시간 등의 실험 인자를 바꿔가며 슬러지 용해 최적조건을 찾고자 하였다. 한편, 펜톤 슬러지를 펜톤 산화용 철 촉매로 재이용하기 위해서는 용해된 펜톤 슬러지 내 철 형태가 2가철 이온으로 존재하는 것이 유리하다. 용해된 펜톤 슬러지 내 철 이온은 대부분 3가철 형태로 존재하는데 Zn, Cd, Cu 등의 금속, 요오드산, 철편 등의 환원제를 투입함으로써 3가철을 2가철 이온으로 환원할 수 있다. 본 연구에서는 영가철을 환원제로 사용하여 용해된 슬러지 내 철 이온을 2가철 이온으로 환원하였다. 용해된 펜톤 슬러지에 영가철을 투입하였고 pH, 반응시간, 영가철 투입량 등 반응 인자를 바꿔가며 펜톤 슬러지 내 2가철 이온 전환의 최적조건을 찾고자 하였다. 두 단계를 거쳐 생성된 펜톤 슬러지 기반의 철 촉매는 실제 RO 농축폐수를 펜톤 산화로 처리할 때 펜톤 산화 시약으로 사용하였으며, 실제 펜톤 산화에서 사용하는 2가철 촉매(FeSO4)와 비교하여 펜톤슬러지 기반의 철 촉매의 효율성을 평가하였다.

The batch tests were performed to determine the ratio of Fenton reagent on diesel contaminated soil. The objective of a column test was to determine and optimize the hydrogen peroxide requirements for the remediation of a soil contaminated with diesel fuel. The batch test were done on 5 g diesel contaminated soil containing hydrogen peroxide (35%) and Iron (II) sulfate. The H2O2(g):Fe2+(g) ratio varied 1:0, 30:1, 15:1, 5:1, 1:1, with contact reaction time 120min. Initial diesel concentration were 2,000 mg/kg, 5,000 mg/kg, and 10,000 mg/kg. Average diesel removal from the contaminated soil is 97% after 2hrs. Results of this study showed possible application of without addition of iron source. In column test, treatment of a diesel-contaminated soil (initial diesel concentration: 2,000 mg/kg, 5,000 mg/kg, and 10,000 mg/kg) with hydrogen peroxide (35%) only was containing natural-occurring minerals. The time required for the column test was approximately 90min, 180min, 270min; column length was 5 cm, 10 cm, and 15 cm. The most effective stoichiometry (final diesel conc.: 200~300 mg/kg) of 0.2 g peroxide consumed/mg diesel degraded. Further investigation is required to identify the effect of soil organic matter and soil mineral.

The purpose of this research is to evaluate the removal efficiencies of CODCr and color for the dyeing wastewater by the different dosages of ferrous solution and H2O2 in Fenton process. In the case of H2O2 divided dosage for the Fenton's reagent 7:3 of H2O2 was more effective than 3:7 to remove CODCr and color. The results showed that CODCr was mainly removed by Fenton coagulation, where the ferric ions are formed in the initial step of Fenton reaction. On the other hand color was removed by Fenton oxidation rather than Fenton coagulation. The removal mechanism of CODCr and color was mainly coagulation by ferrous ion, ferric ion and Fenton oxidation. The removal efficiencies were dependent on the ferric ion amount at the beginning of the reaction. However, the final removal efficiency of CODCr and color was in the order of Fenton oxidation, ferric ion coagulation and ferrous ion coagulation. The reason of the highest removal efficiency by Fenton oxidation can be explained by the chain reactions with ferrous solution, ferric ion and hydrogen peroxide.

The purpose of this study was to evaluate the partial oxidation of the biological treatment plant effluents using Fenton`s reagent as a pretreatment step prior to a tertiary biological oxidation of these effluents. Fenton`s reagent was evaluated as a pretreatment process for inhibitory or refractory organics. Based on the Fenton oxidation system, the petrochemical wastewater treatment plant effluent was shown to have significant improvement in toxicity after oxidation with hydrogen peroxide. For example, at range of 42∼184 ㎎/L COD of petrochemical plant effluents, the COD removal efficiencies were from 38.2% to 60.1% after reaction with hydrogen peroxide 200 ㎎/L and Fe^2+ 100 ㎎/L and reaction time was 30 minutes. The total TOC reduction were about 15.8∼22.4% with same test condition and difference between the overall removal rate and BOD/COD ratio after Fenton`s oxidation estabilished in the biodegradation and otherwise meets the discharge standard or reuse for cooling tower make-up water.

Reuse of industrial effluents through the cooling systems in a petrochemical complex was described. The partial oxidation of the effluents from the biological treatment plant was examined, using Fenton`s reagent as a pretreatment step prior to a next treatment of the effluents. Next tertiary treatment using fixed-film reactor resulted in marked reductions in COD and suspended solids. The continuous fixed-film process with Fenton oxidation pretreatment showed a 23% increase in the COD removal efficiency when compared to that without pretreatment of Fenton oxidation under the volumetric organic loading rate of 0.1 ㎏ COD/㎥/day. The Fenton oxidation treatment seemed to be a possible method for tertiary biological treatment to reduce the residual toxicity with the enhanced biodegradation of the effluents.