不同磷酸盐复合黑曲霉对水体铅污染修复的研究

Study on Remediation of Lead Pollution in Water by Different Phosphates Combined with Aspergillus Niger

本实验探究了难溶性磷酸铁和磷酸钙分别复合黑曲霉对水体铅污染修复的影响。结果表明,添加磷酸铁、磷酸钙和黑曲霉均能降低溶液中铅离子的含量,培养6天后,铅离子的去除率分别为97.20%,98.37%和97.45%。磷酸钙去除的铅离子中可被提取的TCLP-Pb含量最低,为0.06 mg/g,且不受黑曲霉的影响。通过XRD的测定结果表明,在添加磷酸钙与磷酸钙+黑曲霉的处理中均发现了磷氯铅矿的形成。与磷酸钙相比,经磷酸铁处理的TCLP-Pb的含量显著低于经磷酸铁+黑曲霉处理的含量(0.23 mg/g比7.38 mg/g)。与单独添加磷酸铁相比,黑曲霉能够分泌出草酸与铅反应形成的草酸铅矿物,从而降低了铅的有效性。

In this study,the effects of refractory iron phosphate and calcium phosphate combined with A.niger on remediation of lead pollution in water were investigated.The results showed that adding iron phosphate,calcium phosphate and A.niger could reduce the content of lead ions in the solution.After 6 days of incubation,the removal rates of lead ions were 97.20%,98.37%and 97.45%,respectively.Among the lead ions removed by calcium phosphate,the content of available lead(TCLP-Pb)that could be extracted was the lowest,0.06 mg/g,and was not affected by A.niger.XRD results showed that the formation of Pyromorphite(Pyro)was found in the treatment of calcium phosphate and A.niger.Compared with calcium phosphate,the content of TCLP-Pb in iron phosphate treatment was significantly lower than that in iron phosphate+A.niger treatment(0.23 mg/g vs.7.38 mg/g).Compared with adding iron phosphate alone,A.niger can secrete oxalic acid and react with lead to form lead oxalate minerals,which reduces the availability of lead.This result is also verified by XRD results.The results of this study indicate that calcium phosphate is a good material for lead remediation,while iron phosphate requires A.niger to assist in the remediation of lead contamination.