Impact of a mixture of metal ions on the efficiency of packed bed anaerobic reactor treating wastewater
摘要
Heavy metal bioremediation from wastewater has gained great attention due to their high toxicity and non-biodegradable nature. They should be treated before discharge to water bodies. Assessment and evaluation of the impact of different concentrations of a mixture of heavy metal ions, namely Zn2+, Pb2+, Cu2+and Cr6+on the efficiency of a pilot plant hybrid up-flow anaerobic sludge blanket packed with novel packing media treating real municipal wastewater was investigated. The packing media is a novel non-woven polyester fabric (NWPF) that entraps heavy metal ions, subsequently reducing their toxicity on anaerobic sludge that affects the performance of UASB. It promotes faster biomass propagation and organic matter removal due to their unique characteristics and morphology. The size of the reactor was 1.81 m3 and was continually fed with different heavy metal ions at a flow of 5.76 m3/day. Incremental increase of the concentrations of metal ions from 1200 to 13,300 mg/m3 was carried out at different experimental runs. Results indicated that the use of NWPF enhanced the removal efficiency of the mixture of metal ions compared with the conventional UASB. The removal rates of chemical and biological oxygen demands were 67.65 and 77.35% at a total metal concentration of 1200 mg/m3. Further increases in the total concentrations of metal ions to 11-fold decreased the organic removal by 15.43% for COD and 10.58% for BOD. In conclusion, the use of NWPF as a packing material proved to be a promising media for mitigating the effect of heavy metals on UASB performance.