Department of Environmental Sciences, COMSATS University Islamabad, Vehari Campus, Islamabad, 61100, Pakistan.
Department of Civil Engineering, COMSATS University Islamabad, Sahiwal Campus, Islamabad, 57000, Pakistan.
Environ Sci Pollut Res Int. 2024 Apr;31(16):23591-23609. doi: 10.1007/s11356-024-32580-y. Epub 2024 Feb 29.
Arsenic (As)-induced environmental pollution and associated health risks are recognized on a global level. Here the impact of cotton shells derived biochar (BC) and silicon-nanoparticles loaded biochar (nano-Si-BC) was explored on soil As immobilization and its phytotoxicity in barley plants in a greenhouse study. The barley plants were grown in a sandy loam soil with varying concentrations of BC and nano-Si-BC (0, 1, and 2%), along with different levels of As (0, 5, 10, and 20 mg kg). The FTIR spectroscopy, SEM-EDX, and XRD were used to characterize BC and nano-Si-BC. Results revealed that As treatment had a negative impact on barley plant development, grain yield, physiology, and anti-oxidative response. However, the addition of nano-Si-BC led to a 71% reduction in shoot As concentration compared to the control with 20 mg kg of As, while BC alone resulted in a 51% decline. Furthermore, the 2% nano-Si-BC increased grain yield by 94% compared to control and 28% compared to BC. The addition of 2% nano-Si-BC to As-contaminated soil reduced oxidative stress (34% HO and 48% MDA content) and enhanced plant As tolerance (92% peroxidase and 46% Ascorbate peroxidase activity). The chlorophyll concentration in barley plants decreased due to oxidative stress. Additionally, the incorporation of 2% nano-Si-BC resulted in a 76% reduction in water soluble and NaHCO extractable As. It is concluded that the use of BC or nano-Si-BC in As contaminated soil for barley resulted in a low human health risk (HQ < 1), as it effectively immobilized As and promoted higher activity of antioxidants.
砷（As）引起的环境污染及其相关的健康风险在全球范围内受到关注。本研究在温室条件下，探索了棉籽衍生生物炭（BC）和负载纳米硅的生物炭（nano-Si-BC）对土壤中砷固定及其对大麦植株的植物毒性的影响。大麦植株种植在砂壤土中，添加不同浓度的 BC 和 nano-Si-BC（0、1 和 2%），同时添加不同浓度的砷（0、5、10 和 20 mg kg）。采用傅里叶变换红外光谱、扫描电子显微镜-能谱分析和 X 射线衍射对 BC 和 nano-Si-BC 进行了表征。结果表明，砷处理对大麦植株的生长发育、籽粒产量、生理特性和抗氧化响应均产生了负面影响。然而，添加 nano-Si-BC 可将 20 mg kg 砷处理下的植株地上部砷浓度降低 71%，而单独添加 BC 则降低 51%。此外，添加 2% nano-Si-BC 可使大麦籽粒产量分别比对照和 BC 处理提高 94%和 28%。向砷污染土壤中添加 2% nano-Si-BC 可降低氧化应激（HO 降低 34%，MDA 降低 48%），增强植物砷耐性（过氧化物酶提高 92%，抗坏血酸过氧化物酶提高 46%）。由于氧化应激，大麦植株的叶绿素浓度降低。此外，添加 2% nano-Si-BC 可使水溶态和 NaHCO3 可提取态砷分别降低 76%。综上，在砷污染土壤中添加 BC 或 nano-Si-BC 种植大麦，由于砷的固定效果好，抗氧化剂活性高，对人体健康的风险较低（HQ<1）。
