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污染土壤的有效方法具有重要意义。很少确定在不同的温度和湿度条件下，纳米铁颗粒（Fe）可以有效地从土壤中去除重金属。因此，本研究的目的是研究0.5（N1），1.0（N2）和2.0％（N3）时，包括零价铁（nZVI = Fe0）和磁铁矿（nFe3O4 = Fe1）的铁对铁的影响。从受不同时间（24（T1），48（T2）和72 h（T3）），温度（15（Te1），25（Te2）和35°C（Te3））和水分处理影响的土壤中去除铬（饱和（M1），60（M2）和100％（M3）的场容量）。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）显着影响了从污染土壤中去除铬。结果表明，对于两种纳米源，N1是去除铬最有效的方法，其次是N2和N3。影响土壤中铬去除的两种纳米源之间的显着差异很小（P = .0513）。Fe * N的显着相互作用表明，在每个N速率下，纳米源对Cr去除的影响可能不同。温度也显着影响了铬从污染土壤中的去除，因为铬是单一的，并且与速率（N）和纳米（Fe）来源的相互作用也很显着。与Te2相比，Te1和Te3，与M1相比，M2和M3是除铬最有效的方法。尽管单一时间对铬去除的影响不显着，但它与纳米源和水分的相互作用很显着，这表明更长的时间和水分含量可能会影响纳米铁元素从污染土壤中去除铬的效率。