the study of remedial technology and management of mercury-contaminated site

• Main Authors: Yen, Jia-Huei, 顏佳慧
• Other Authors: Chang, Tien-Chin
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/01469256854473060059

碩士 === 國立臺北科技大學 === 環境規劃與管理研究所 === 91 === In recent years, soil pollution has become a serious problem in Taiwan. The most cases are the unsuitable disposal or spill accident of industries. Many contaminated sites had been found in Taoyuan plant of the Radio Corporation of America (RCA) for chlorinated hydrocarbons spill. In this study, the site of His-Fang Chemical Factory was suffered from mercury pollution by the liquid chlorine and sodium hydrate produced from mercury electrolytic method in early years. From the result, about 504mg/kg of mercury was found in the soil, and this was obviously higher than the background grade of heavy metal in soil 0.1~0.39 mg/kg in Taiwan. Thermal desorption treatment was implemented in this site, and the amount of mercury residue was less than 2mg/kg after the treatment process. This showed the remarkable effect from the result. After desorption, the mercury was condensed into sludge, the average mercury concentration of which was between 47.5×103 and 237.1×103 mg/kg. And 32 kg wet mercury sludge was produced everyday on average. The remediation site treated flue gas and wastewater with Sulfur-impregnated activated carbon, and about 300 kg activated carbon was needed during steady treatment time. 1.24 kg waste activated carbon, which would be put into stove for further desorption, was produced for treating 1 m3 soil. This activated carbon was placed in kiln desorption after remediation. The remediation process was complying with workers safety sanitation regulations. Fire extinguisher and protective equipment were also prepared in the plant. The emergent processes start such as earthquake and typhoon. The economic analysis for thermal desortion included build cost, operation & management and factory closed cost, about US$1,364 thousand (38%), US$1,989 thousand (56%) and US$204 thousand (6%), respectively. The total cost was about US$3,557 thousand. The remediation site treated 4264 m3 altogether, with the treatment cost of US$ 834 per m3 soil.