ABSTRACT

Finding an efficient method, which may decrease the pollution of soil by heavy metals, is of significance. It has been rarely determined that nano-iron particles (Fe), can contribute to the efficient removal of heavy metals from the soil under different temperature and moisture conditions. Accordingly, the objective of the present research was to investigate the effects of Fe including zero-valent iron (nZVI = Fe0) and magnetite (nFe3O4 = Fe1), at 0.5 (N1), 1.0 (N2) and 2.0% (N3) on Cr removal from a contaminated soil affected by different times (24 (T1), 48 (T2) and 72 h (T3)), temperatures (15 (Te1), 25 (Te2) and 35°C (Te3)) and moisture treatments (saturated (M1), 60 (M2), and 100% (M3) of field capacity). According to the analysis of variance the experimental treatments (Fe, N, Te and M) and their interactions (Fe*N; Fe*N*Te and Fe*T*M) significantly affected Cr removal from the contaminated soil. The results indicated, for both nano sources, N1 was the most effective treatment on Cr removal, followed by N2 and N3. The significant differences between the two nano sources affecting Cr removal from the soil was marginal (P = .0513). The significant interaction of Fe*N indicates the effects of the nano sources on Cr removal may be different at each N rate. Temperature also significantly affected Cr removal from the contaminated soil as its single and its interaction effects with the rate (N) and source of nano (Fe) were significant. Te1 and Te3, compared with Te2, and M2 and M3, compared with M1, were the most efficient ones for Cr removal. Although time single effect was not significant on Cr removal, its interaction with nano source and moisture was significant indicating a longer time and moisture level may affect the efficiency of Cr removal from the contaminated soil by Fe nano sources.

摘要

寻找一种可以减少重金属对土壤污染的有效方法具有重要意义。很少确定纳米铁颗粒 (Fe) 在不同温度和湿度条件下有助于有效去除土壤中的重金属。因此，本研究的目的是研究包括零价铁 (nZVI = Fe0) 和磁铁矿 (nFe3O4 = Fe1) 的 Fe 的影响，浓度为 0.5 (N1)、1.0 (N2) 和 2.0% (N3)受不同时间（24 (T1)、48 (T2) 和 72 h (T3)）、温度（15 (T1)、25 (Te2) 和 35°C (Te3)）和水分处理影响的受污染土壤中 Cr 的去除（场容量的饱和 (M1)、60 (M2) 和 100% (M3)）。根据方差分析，实验处理（Fe、N、Te 和 M）及其相互作用（Fe*N；Fe*N*Te 和 Fe*T*M) 显着影响了污染土壤中 Cr 的去除。结果表明，对于两种纳米源，N1 是去除 Cr 最有效的处理方法，其次是 N2 和 N3。影响从土壤中去除 Cr 的两种纳米源之间的显着差异是微不足道的（P = .0513）。Fe*N 的显着相互作用表明纳米源对 Cr 去除的影响在每个 N 速率下可能不同。温度也显着影响 Cr 从污染土壤中的去除，因为它的单一及其与速率 (N) 和纳米 (Fe) 来源的交互作用是显着的。Te1 和Te3 与Te2 相比，M2 和M3 与M1 相比，去除Cr 的效率最高。虽然时间单一效应对 Cr 去除的影响不显着，但其与纳米源和水分的相互作用显着，表明较长的时间和水分含量可能会影响 Fe 纳米源从污染土壤中去除 Cr 的效率。