Heavy Metal Removal from Contaminated River Sediment Using Bioleaching Process

• Main Authors: Kun-Hong Lin, 林昆宏
• Other Authors: Jin-Gaw Lin
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/71081761096641011431

碩士 === 國立交通大學 === 環境工程所 === 91 === Because riverbed sediments act as potential sources of contaminants in aquatic environment, and most of pollutant were polluted by human, industrial and urban waste discharge into river system. The present study in bioleaching costs low of treatment and ease of operation. In order to enhance the sulfur oxidation rate. Sulfur powder, which provides larger surface area for the adsorption of sulfur-oxidizing bacteria. However, sulfur-oxidizing bacteria used only 30-40% of sulfur powder during bioleaching process. The unrecoverable sulfur powder remaining in treated sediments increases the operational costs and causes acidification of the disposal land. Therefore, it is necessary to use recoverable forms of sulfur as substrates for sulfur-oxidizing bacteria in the bioleaching. In this study, the recovered of sulfur pellets on bioleaching of heavy metal from contaminated sediment were investigated. Adding recovered sulfur pellets at the beginning of bioleaching process, in order to increase bioconcentraion in an air-lifting reactor. With times of recovery increased, could accelerate the rates of acidification, sulfate production and metal solubilization. One was change sediment solid content. The results showed that the rate of pH reduction decreased with increasing sediment solid content because of the buffering capacity of sediment solid content. For different solid contents (1-10% (w/w)), 34-74% (w/w) of Ni; 40-84% (w/w) of Mn; 56-99% of Cu; 62-99% of Zn; 21-38% of Pb; 14-49% of Cr were leached from sediments in the bioleaching process. The optimal sediment solid content in the bioleaching was 2% (w/w). Another was change inoculum concentration (0-15% (v/v)), the optimal concentration of inoculum concentration added in the bioleaching was 10% (v/v). When adding 15% (v/v) of inoculum concentration to the bioleaching, inhibition of acidification, sulfate production and metal solubilization were fond. And the recovery of sulfur pellets could reach 90-95%, the results decrease sulfur in the treated sediments.