Application of Zn-contaminated soil: Feasibility study on the removal of H2S from hot coal-derived gas

In this study, zinc-contaminated soils were chosen as a candidate material for the removal of hydrogen sulfide (H₂S) from hot coal-derived gas. Laboratory experiments showed that H₂S was decreased to less than 10 ppm when the zinc-contaminated soils were reacted with H₂S. The best removal temperature of H₂S was found to be at 550°C in the operating conditions. In addition to zinc species, free iron oxides in contaminated soils also performed an active species to react with H₂S and enhanced the sulfur capacity. Through the XPS analysis, iron sulfide (FeS) and zinc sulfide (ZnS) were the major products after removal experiments. Regeneration experimental results indicated that the zinc-contaminated soils can be regenerated by pass diluted air and thus be reused on the removal of H₂S for many times.     

Effects of ozonation and coagulation on effluent organic matter characteristics and ultrafiltration membrane fouling

Effluent organic matter （EfOM） is the major cause of fouling in the low pressure membranes process for wastewater reuse. Coagulation and oxidation of biological wastewater treatment effluent have been applied for the fouling control of microfiltration membranes. However, the change in EfOM structure by pre-treatments has not been clearly identified. The changes of EfOM characteristics induced by coagulation and ozonation were investigated through size exclusion chromatography, UV/Vis spectrophotometry, fluorescence spectrophotometry and titrimetric analysis to identify the mechanisms in the reduction of ultrafiltration （UF） membrane fouling. The results indicated that reduction of flux decline by coagulation was due to modified characteristics of dissolved organic carbon （DOC） content. Total concentration of DOC was not reduced by ozonation. However, the mass fraction of the molecules with molecular weight larger than 5 kDa, fluorescence intensity, aromaticity, highly condensed chromophores, average molecular weight and soluble microbial byproducts decreased greatly after ozonation. These results indicated that EfOM was partially oxidized by ozonation to low molecular weight, highly charged compounds with abundant electron- withdrawing functional groups, which are favourable for alleviating UF membrane flux decline.     

The effective control of major industrial accidents by the Major Industrial Accident Prevention Centers (MAPC) through the Process Safety Management (PSM) grading system in Korea

This paper examines effectiveness of a regulatory enforcement organization (Major industrial Accident Prevention Center, MAPC), and a grading system for implementation of the Process Safety Management (PSM) regulation in Korea. A lot of chemical installations have been built in Korea since the 1960s. The frequent occurrence of major industrial accidents had made people's concerns grow. The Korean government enacted PSM regulations in 1996 in order to curb these accidents.However, a key question is how to make sure companies comply with the PSM regulations. In order to improve company’ compliance with PSM regulations the Ministry of Employment and Labor (MOEL) responsible for the regulation introduced a grading management system in 2001 and then established special supervisory centers for enforcement of PSM regulations in 2005. This paper reviews the role and effectiveness of the system in term of PSM enforcement. The author found that the grade-based approach has encouraged employers to implement the requirements of the PSM regulations. MAPCs play an effective role in enhancing enforcement performance. Although the more chemical plants have been established in Korea, the fewer major industrial accidents have occurred since the introduction of the system. The results may be useful for the policy maker to build an effective and efficient enforcement system.     

Solid recovery rate of food waste recycling in South Korea

Source-separated collection system of household food waste has been implemented national wide in South Korea. Food waste recycling rate that means conversion rate to recycle is over 90 % in present. However, over the value of 90 %, we need to enhance the efficiency of food waste recycling process. We analyzed material flow of 24 food waste recycling facilities and calculated solid recovery rate to key-process. We found that 3–13 % of the solids from food waste outflows with foreign materials and 27–33 % of the solids outflow with wastewater. As a result, solid recovery rates are 65.3, 60.9, and 56.3 % in wet feed facility, dry feed facility, and composting facility, respectively. Alternative ways to recovery solid from wastewater or collection tools to exclude plastic bags, salt, and moisture content are required to make food waste recycling more efficient.     

Impacts of mycotoxin on biohydrogen production from waste dry fruits

Journal of Material Cycles and Waste Management - Discarded dry fig and raisin, which exporting companies have to claim and destroy, were subjected to batch dark fermentation at 37 °C...     

Health risk assessment and source apportionment of PM2.5-bound toxic elements in the industrial city of Siheung,Korea

Environmental Science and Pollution Research - The emission sources and their health risks of fine particulate matter (PM2.5) in Siheung, Republic of Korea, were investigated as a middle-sized...