Ghasemzadeh Parisa, Bostani Amir
Department of Soil Science, Faculty of Agriculture, Shahed University, Tehran, Iran.
Ph.D., Assistant Professor of Soil Science, Faculty of Agriculture, Shahed University, Tehran, Iran.
Ecotoxicol Environ Saf. 2017 Nov;145:483-489. doi: 10.1016/j.ecoenv.2017.06.066. Epub 2017 Aug 4.
Reducing the concentration of heavy metals including lead (Pb) and nickel (Ni) in organic contaminants such as municipal wastes and sewage sludge is of health and environmental importance. Nanoscale zero-valent iron (NZVI) particles can effectively remove heavy metals from contaminated aqueous and solid media. It was accordingly hypothesized that it is possible to recycle and detoxify organic waste materials containing heavy metals using NZVI and NZVI fixed on quartz (QNZVI). The objective was to investigate the effects of NZVI type, concentration (2% and 5%) and contact time on the removal of Pb and Ni from raw compost, compost fermented with beet molasses, and leachate using a factorial design. The results indicated the significant reduction of DTPA- Pb and DTPA-Ni concentration, in all the organic compounds treated with NZVI and QNZVI (P= 0.01), compared with control. Increased concentration of NZVI in all treatments, increased the rate of DTPA-Pb and DTPA-Ni (P= 0.01) at 113.1% and 180% for Pb (NZVI at 2% and 5%), and at 16.3% and 23.3% for Ni, irrespective of the NZVI type. The reducing trend of extractable Pb and Ni in all the organic compounds was the same, quick reduction at the beginning, followed by a negligible rate. The highest reduction rates for Pb (at one hour) and Ni (at 672h) were equal to 72.93% and 23.27%, respectively. NZVI at 2% was more efficient than NZVI at 5%. There were not any significant differences between NZVI and QNZVI on the removal of Pb and Ni from the organic contaminants. It is possible to immobilize and reduce the concentration of heavy metals such as Pb and Ni in organic contaminants using NZVI, which is affected by NZVI properties, concentration, and contact time, as well as by organic contaminant type.
降低城市垃圾和污水污泥等有机污染物中包括铅（Pb）和镍（Ni）在内的重金属浓度对健康和环境具有重要意义。纳米级零价铁（NZVI）颗粒可以有效地从受污染的水相和固相介质中去除重金属。因此，有人提出假设，利用NZVI和固定在石英上的NZVI（QNZVI）可以对含有重金属的有机废料进行回收和解毒。目的是采用析因设计研究NZVI类型、浓度（2%和5%）以及接触时间对从生堆肥、用甜菜糖蜜发酵的堆肥和渗滤液中去除Pb和Ni的影响。结果表明，与对照相比，在用NZVI和QNZVI处理的所有有机化合物中，DTPA-Pb和DTPA-Ni浓度显著降低（P = 0.01）。在所有处理中，NZVI浓度的增加提高了DTPA-Pb和DTPA-Ni的去除率（P = 0.01），对于Pb，去除率分别为113.1%和180%（2%和5%的NZVI），对于Ni，去除率分别为16.3%和23.3%，与NZVI类型无关。所有有机化合物中可提取的Pb和Ni的降低趋势相同，开始时快速降低，随后速率可忽略不计。Pb（1小时）和Ni（672小时）的最高去除率分别等于72.93%和23.27%。2%的NZVI比5%的NZVI更有效。在从有机污染物中去除Pb和Ni方面，NZVI和QNZVI之间没有显著差异。利用NZVI可以固定并降低有机污染物中Pb和Ni等重金属的浓度，这受到NZVI性质、浓度、接触时间以及有机污染物类型的影响。
