Yang Wei, Dai Huiping, Wei Shuhe, Robinson Brett H, Xue Jianming
Academy of Environmental and Chemical Engineering, Shenyang Ligong University, Shenyang, 110159, Liaoning, China.
College of Biological Science & Engineering, Shaanxi Province Key Laboratory of Bio-resources, Shaanxi University of Technology, Hanzhong 723001, China.
Chemosphere. 2024 Mar;352:141317. doi: 10.1016/j.chemosphere.2024.141317. Epub 2024 Jan 27.
The efficacy of using plants to phytoremediate heavy metal (HM) contaminated soils can be improved using soil amendments. These amendments may both increase plant biomasses and HMs uptake. We aimed to determine the composite effect of ammonium sulfate ((NH)SO) combined with the application of an aqueous stem-extracted bio-chelator (Bidens tripartita L) on the plant biomasses and cadmium (Cd) phytoextraction by Solanum nigrum L. The constant (NH)SO application mode plus bio-chelator additives collectively enhanced the shoot Cd extraction ability owing to the increased plant biomass and shoot Cd concentration by S. nigrum. The shoot Cd extraction and the soil Cd decreased concentration confirmed the optimal Cd phytoextraction pattern in K8 and K9 treatments (co-application of (NH)SO and twofold/threefold bio-chelators). Accordingly, Cd contamination risk in the soil (2 mg kg) could be completely eradicated (<0.2 mg kg) after three rounds of phytoremediation by S.nigrum based on K8 and K9 treatments through calculating soil Cd depletion. The microorganism counts and enzyme activities in rhizosphere soils at treatments with the combined soil additives apparently advanced. In general, co-application mode of (NH)SO and aqueous bio-chelator was likely to be a perfect substitute for conventional scavenger agents on account of its environmental friendliness and cost saving for field Cd contamination phytoremediation by S. nigrum.
使用土壤改良剂可以提高利用植物对重金属（HM）污染土壤进行植物修复的效果。这些改良剂既可以增加植物生物量，又能提高对重金属的吸收。我们旨在确定硫酸铵（(NH₄)₂SO₄）与茎提取物生物螯合剂（鬼针草）联合施用对龙葵植物生物量和镉（Cd）植物提取的综合影响。由于龙葵植物生物量和地上部Cd浓度增加，持续施用(NH₄)₂SO₄加上生物螯合剂添加剂共同提高了地上部Cd提取能力。地上部Cd提取量和土壤Cd浓度降低证实了K8和K9处理（(NH₄)₂SO₄与两倍/三倍生物螯合剂联合施用）中最佳的Cd植物提取模式。因此，通过计算土壤Cd消耗，基于K8和K9处理，龙葵进行三轮植物修复后，土壤中Cd污染风险（2 mg/kg）可完全消除（<0.2 mg/kg）。联合土壤添加剂处理的根际土壤中微生物数量和酶活性明显提高。总体而言，(NH₄)₂SO₄与生物螯合剂水溶液的联合施用模式因其环境友好性和成本节约，可能是龙葵对田间Cd污染进行植物修复时传统清除剂的理想替代品。
