ABSTRACT

The use of ammonium iron (II) sulphate ((NH₄)₂Fe(SO₄)₂) to remediate soil contaminated with Cr (VI) was assessed. (NH₄)₂Fe(SO₄)₂ effectively remediated soil contaminated with Cr (VI) and, acted as a fertilizer by supplying nitrogen because it contains ammonium. The effects of the (NH₄)₂Fe(SO₄)₂ dose, water content, pH of the soil and the contact time were investigated. The amount of Cr (VI) leached from the most-polluted soil, determined using a leaching toxicity procedure using optimized conditions, was 347.64 mg kg⁻¹ when the soil was untreated and 6.74 mg kg⁻¹ when the soil was treated with (NH₄)₂Fe(SO₄)₂. Bio-utilizable Cr contributed 59.44% and 0.16% of the total Cr contents of the untreated and treated soil, respectively. The relatively stable Cr species contributed 24.92% and 98.38% of the total Cr contents of the untreated and treated soil, respectively. The results indicated that adding (NH₄)₂Fe(SO₄)₂ markedly decreased the risk of Cr being released from heavily contaminated soil by decreasing the availability of Cr in the soil. Overall, the results indicated that adding (NH₄)₂Fe(SO₄)₂ causes some Cr (VI) in contaminated soil to be reduced to Cr (III), and to form a precipitate, which decreases the risk of Cr being released. (NH₄)₂Fe(SO₄)₂ can be applied to soil contaminated with Cr (VI) on a large scale because it is cheap and simple to achieve.

摘要

评估了使用硫酸铁 (II) 铵 ((NH ₄ ) ₂ Fe(SO ₄ ) ₂ ) 修复受 Cr (VI) 污染的土壤。(NH ₄ ) ₂ Fe(SO ₄ ) ₂有效地修复了被Cr (VI) 污染的土壤，并通过提供氮作为肥料，因为它含有铵。考察了(NH ₄ ) ₂ Fe(SO ₄ ) ₂剂量、含水量、土壤pH值和接触时间的影响。从污染最严重的土壤中浸出的 Cr (VI) 的量是 347.64 mg kg^-1当土壤未经处理时，6.74 mg kg ^-1当土壤用(NH ₄ ) ₂ Fe(SO ₄ ) ₂处理时。生物可利用铬分别占未处理和处理土壤总铬含量的 59.44% 和 0.16%。相对稳定的 Cr 物种分别占未处理和处理土壤总 Cr 含量的 24.92% 和 98.38%。结果表明，添加(NH ₄ ) ₂ Fe(SO ₄ ) ₂通过降低土壤中Cr的有效性，显着降低了Cr从重度污染土壤中释放的风险。总体而言，结果表明添加（NH ₄) ₂ Fe(SO ₄ ) ₂使污染土壤中的部分Cr(VI)还原为Cr(III)，形成沉淀，降低Cr释放的风险。(NH ₄ ) ₂ Fe(SO ₄ ) ₂可以大规模应用于被Cr(VI)污染的土壤，因为它便宜且易于实现。