Abstract:
Antimony contamination from textile industries has been a global environmental concern and the existing treatment technologies could not reduce Sb(V) to meet the discharge standards. To overcome this shortcoming, ferric flocs were introduced to expedite the biological process for enhanced Sb(V) removal in wastewater treatment plant (WWTP). For this purpose, a series of laboratorial-scale sequential batch reactor activated sludge processes (SBRs) were applied for Sb(V) removal with varied reactor conditions and the transformation of Fe and Sb in SBR system was investigated. Results showed a significant improvement in Sb(V) removal and the 20 mg L-1 d-1 iron ions dosage and iron loss rate was found to be only 15.2%. The influent Sb(V) concentration ranging 153-612 μg L-1 was reduced to below 50 μg L-1, and the maximum Sb(V) removal rate of the enhanced system reached about 94.3%. Furthermore, it exhibited high stability of Sb(V) removal in the face of antimonate load, Fe strike and matrix change of wastewater. Sludge total Sb determination and capacity calculation revealed decreasing in Sb adsorption capacity and desorption without fresh Fe dosage. While sludge morphology analysis demonstrated the aging and crystallization of iron hydroxides. These results verify the distinct effects of fresh iron addition and iron aging on Sb(V) removal. High-throughput gene pyrosequencing results showed that the iron addition changed microbial mechanisms and effect Fe oxidized bacterial quantity, indicating Sb(V) immobilization achieved by microbial synergistic iron oxidation. The present study successfully established a simple and efficient method for Sb(V) removal during biological treatment, and the modification of biological process by iron supplement could provide insights for real textile wastewater treatment.
摘要:
纺织工业的锑污染已成为全球环境问题,现有的处理技术无法减少Sb(V)以满足排放标准。为了克服这个缺点,在污水处理厂(WWTP)中引入了铁絮凝物,以加快生物工艺以增强Sb(V)的去除。为此,在不同的反应器条件下,采用一系列实验室规模的顺序间歇式反应器活性污泥法(SBR)去除Sb(V),并研究了SBR系统中Fe和Sb的转化。结果表明,Sb(V)的去除率显着提高,20mgL-1d-1铁离子用量和铁损失率仅为15.2%。进水Sb(V)浓度范围为153-612μgL-1,降至50μgL-1以下,增强系统的最大Sb(V)去除率达到约94.3%。此外,它在锑酸盐负载下表现出高的Sb(V)去除稳定性,废水的铁冲击和基质变化。污泥总Sb的测定和容量计算表明,在没有新鲜Fe用量的情况下,Sb的吸附容量和解吸量会降低。而污泥形态分析表明了氢氧化铁的老化和结晶。这些结果验证了新鲜铁的添加和铁老化对Sb(V)去除的不同影响。高通量基因焦磷酸测序结果表明,铁的添加改变了微生物的作用机制,表明通过微生物协同铁氧化实现Sb(V)固定。本研究成功建立了一种简单高效的生物处理中Sb(V)的去除方法。补铁对生物工艺的改性可以为实际的纺织废水处理提供见解。