Variation of physiochemical factors during the treatment of river sediment polluted with heavy metals by bioleaching

• Main Authors: Hui-wen Ling, 凌彗紋
• Other Authors: none
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/13279076418403574014

碩士 === 嘉南藥理科技大學 === 環境工程與科學系碩士班 === 92 === Abstract The aim of this study is to find the possibility of metal released from sediment, the variation of physicochemical factors in sediment and the accompanying release of PAHS by bioleaching. The experiments were designed under four different operational conditions which varied in sediment sterilization and substrate adding each other, to find the variation of physicochemical factors and binding fractions in sediment. Results reveal that the most significant leaching effect of metals from sediment could be found in the test operated under the condition with sediment non- sterilization and substrate adding. Meanwhile, the pH of sediment decreased with time whereas the ORP increased. Particle size distribution tended to concentrate on the range of silt in the process of bioleaching. Meanwhile, the specific surface area of particles increased with the decrease of particle size as well as element oxygen in particles increased. The releases of 4-rings, 5-rings and 6-rings PAHS in the test operated under the condition with sediment non- sterilization and substrate adding significantly increased with the decrease of sediment pH. Among the process of bioleaching, it can be noted that the variation of binding fractions of different metals was insignificant. Cadmium similar to cobalt, mainly bound to carbonates and organics; chromium similar to iron, mainly bound to Fe-oxides and organics; manganese similar to lead, mainly bound to Fe-oxides, organics and carbonates. The order of metals released from sediment found in the test operated under the condition with sediment non- sterilization and substrate adding was as follows: Ni(63.50%), Fe(59.83%), Cu(59.01%), Zn(57.60%), Cr(47.05%), Pb(39.23%), Mn(38.69%), Ca(38.04%), Cd(25.37%), Co(18.02%).