Research On Removal Of Heavy Metals From Sludge By Bioleaching And Circulation Of The Sediment Process

Sewage sludge containing heavy metal is hindering the sludge treatment and utilization of important factors, through the efficient, economical treatment processes for the removal of heavy metals in sludge so as to realize the resource utilization of sludge, sludge disposal technology is currently the research focus of the. Bioleaching of heavy metals in the sludge has good removal effect and relatively simple process operation conditions, is applied to the mainstream technology of sludge treatment.To the north of Shenyang city sewage treatment plant sludge concentration as the research object, in order to cultivate Thiobacillus thiooxidans mixed mainly thiobacillus for bioleaching, reduce or remove the heavy metals in the sludge, the sludge of heavy metals in accord with our country" agricultural sludge pollution control standards"(GB4284-1984); by bacterial culture matrix of different proportion, looking for the suitable matrix proportion, so as to shorten the bioleaching process start time, improve the bioleaching process for heavy metal removal efficiency; repeated use of bioleaching sludge, bioleaching efficiency to improve, reduce the bioleaching process matrix energy substance use, for the bioleaching process of actual application and promotion foundation. The results show that(1) in the elemental S as matrix culture mixed thiobacillus for bioleaching process for heavy metal removal effect is good, heavy metal concentrations were lower in. For Ni, Zn, Pb, Cu, Cd, Mn and other6kinds of heavy metal removal rates are:81.98%,88.20%,39.17%,83.35%,19.64%,82.01%. Leaching sludge heavy metal concentrations in accord with our country" agricultural sludge pollution control standards"(GB4284-1984).(2) Fe2+addition to activation by bacterial Fe2+oxidase synthesis, be helpful for accelerating thiobacilli on S oxidation using elemental sulfur, while also promoting microorganism on Fe2+use. Test will train mixed strain cycle was shortened to11days, S, Fe2the best substrate ratio was determined for3:1, the matrix culture mixed Thiobacillus is faster, and can greatly improve the bioleaching boot efficiency.(3) sediment circulating biological leaching for heavy metals Ni, Zn, Cu total removal rate of no ordinary bioleaching is high, the highest removal rates were46.29%,69.59%,82.62%. Mud circulation of bioleaching for heavy metals Pb, Cd, Mn gross removal effect is better than common bioleaching, respectively71.70%,80.67%,86.83%.(4) sediment circulating leaching on removal of heavy metals Ni, Pb, Cd acid soluble and exchangeable good effect, removal rates can reach92.15%,99%,81%. Mud circulating leaching on removal of heavy metals Zn, Cu, Cd, Mn reducible better achieve respectively89.57%,60.81%,99.99%,96%. On6kinds of heavy metals in sediment circulation results in the oxidation state of the removal rate is maintained at a high level. Mud circulating leaching on heavy metals Zn, Pb, Cd, Mn residue state higher removal efficiency of heavy metals, Ni appeared residual enrichment.(5) sludge recycling saves bacterial culture period, while reducing the substrate utilization, has the widespread application value, practical application.