Faculty of Energy and Environmental Studies, Islamic Azad University, Science and Research Branch, Hesarak, Tehran, Iran.
J Hazard Mater. 2011 Jul 15;191(1-3):118-25. doi: 10.1016/j.jhazmat.2011.04.045. Epub 2011 Apr 28.
Petrochemical factories which manufacture vinyl chloride monomer and poly vinyl chloride (PVC) are among the largest industries which produce wastewater contains mercury and cadmium. The objective of this research is to evaluate the performance of a lab-scale Sequencing Batch Reactor (SBR) to treat a synthetic petrochemical wastewater containing mercury and cadmium. After acclimatization of the system which lasted 60 days, the SBR was introduced to mercury and cadmium in low concentrations which then was increased gradually to 9.03±0.02 mg/L Hg and 15.52±0.02 mg/L Cd until day 110. The SBR performance was assessed by measuring Chemical Oxygen Demand, Total and Volatile Suspended Solids as well as Sludge Volume Index. At maximum concentrations of the heavy metals, the SBR was able to remove 76-90% of Hg(2+) and 96-98% of Cd(2+). The COD removal efficiency and MLVSS (microorganism population) in the SBR was affected by mercury and cadmium concentrations in influent. Different species of microorganisms such as Rhodospirilium-like bacteria, Gomphonema-like algae, and sulfate reducing-like bacteria were identified in the system. While COD removal efficiency and MLVSS concentration declined during addition of heavy metals, the appreciable performance of SBR in removal of Hg(2+) and Cd(2+) implies that the removal in SBR was not only a biological process, but also by the biosorption process of the sludge.
生产氯乙烯单体和聚氯乙烯（PVC）的石化工厂是生产含有汞和镉废水的最大工业之一。本研究的目的是评估实验室规模的序批式反应器（SBR）处理含有汞和镉的合成石化废水的性能。在经过 60 天的系统驯化后，SBR 开始处理低浓度的汞和镉，然后逐渐增加到 9.03±0.02mg/L Hg 和 15.52±0.02mg/L Cd，直到第 110 天。通过测量化学需氧量、总悬浮固体和挥发性悬浮固体以及污泥体积指数来评估 SBR 的性能。在重金属的最大浓度下，SBR 能够去除 76-90%的 Hg(2+)和 96-98%的 Cd(2+)。SBR 中的 COD 去除效率和 MLVSS（微生物种群）受到进水重金属浓度的影响。在系统中鉴定出了类似于红螺旋菌的细菌、类似于衣藻的绿藻和类似于硫酸盐还原菌的细菌等不同种类的微生物。虽然在添加重金属时 COD 去除效率和 MLVSS 浓度下降，但 SBR 在去除 Hg(2+)和 Cd(2+)方面的良好性能表明，SBR 的去除不仅是一个生物过程，也是污泥的生物吸附过程。
