Cr(VI)-contaminated soils could be remediated by using calcium polysulfide (CPS), while natural iron oxides as a main composition of soil would influence the pathways of the remediation. Through kinetic batch tests, the kinetics of Cr(VI) removal from soil, the effects of the contents of natural iron oxides, soil environmental conditions and mechanisms of Cr(VI) removal by using CPS with the presence of natural iron oxides were investigated. The results show that the removal of Cr(VI) by using CPS in soil fitted the pseudo-second-order model best, and the appearance of goethite increased the apparent rate constant from 0.0002 kg mg⁻¹ h⁻¹ to 0.0005 kg mg⁻¹ h⁻¹. The presence of iron oxides enhanced the removal of Cr(VI) by using CPS, and an extended reductive atmosphere of soil was created. The enhancement of Cr(VI) removal increased with the contents of iron oxides from 0 to 9 g kg⁻¹, and declined from 9 to 12 g kg⁻¹. Acidic environment favored the removal of Cr(VI) from soil by using CPS with or without the iron oxides compared to neutral soil and increased it from 87% to 100% because of proton-consuming reactions and electrostatic attraction. Twenty-nine percent of exchangeable and bound-to-carbonates species of chromium declined after the remediation, while 24% bound-to-iron-and-manganese-oxide species increased simultaneously. The findings of the study indicate that natural iron oxides in soils catalyze the reduction of Cr(VI) in soil and facilitate significantly the remediation of Cr(VI)-contaminated soil by using CPS.

可以使用多硫化钙（CPS）修复受Cr（VI）污染的土壤，而天然氧化铁作为土壤的主要成分将影响修复的途径。通过动力学分批测试，研究了从土壤中去除六价铬的动力学，天然铁氧化物含量的影响，土壤环境条件以及在天然铁氧化物存在下使用CPS去除六价铬的机理。结果表明，通过在土壤中使用CPS去除铬（VI）的嵌合伪二阶模型最好，针铁矿的外观从0.0002提高表观速率常数千克毫克^-1 ħ ^-1 0.0005千克毫克^{- 1}小时^-1。铁氧化物的存在通过使用CPS增强了Cr（VI）的去除，并创造了扩大的土壤还原气氛。Cr（VI）去除的增强随着氧化铁含量的增加而从0降低到9 g kg ^-1，从9降低到12 g kg ^-1。与中性土壤相比，酸性环境有利于使用含或不含铁氧化物的CPS从土壤中去除Cr（VI），并且由于质子消耗反应和静电吸引，其从87％增至100％。修复后，有29％的可交换和与碳酸盐结合的铬物种减少，而与铁和锰的氧化物结合的24％铬元素同时增加。研究结果表明，土壤中的天然氧化铁可催化土壤中Cr（VI）的还原，并通过使用CPS显着促进对受Cr（VI）污染的土壤的修复。