Abstract

Maize (Zea mays L.) is considered as a potential energy-yielding crop which may respond to compost application for arsenic (As) phytoremediation depending on soil type and compost application levels in soil. Here, we explored compost-mediated As phytoremediation potential of maize in the two different textured soils (sandy loam soil and clay loam soil) at varying As (0–120 mg kg⁻¹) and compost (0–2.5%) levels under glasshouse conditions. Results revealed that in the absence of compost maize plants grown at different soil As levels (0–120 mg kg⁻¹) accumulated 1.20–1.71 times more As from sandy loam soil than that of clay loam soil. The compost addition in soil at all levels, with 120 mg kg⁻¹As enhanced As accumulation in maize plants in the clay loam soil by 13%, while it reduced As phyto-uptake by 27% in sandy loam soil. This may be due to an increase in phosphate-extractable (bioavailable) soil As content from 2.7 to 3.8 mg kg⁻¹ in clay loam soil. The estimated daily intake (EDI) of As (0.03–0.15 μg g⁻¹ of body weight day⁻¹) was above the US EPA’s standard value. Arsenic phytoremediation potential of the maize plants was found to be economical for sandy loam soil with 1% compost level and for clay loam soil at 2.5% compost level, suggesting soil type specific dose dependence of compost for As phytoremediation programs.

Novelty statement: To our knowledge, the role of compost in economic feasibility of energy crops at contaminated soils in general, and in the growing of maize at As-contaminated soil in particular, has not been addressed, so far. Moreover, it is the first time to evaluate environmental and health risk of compost-mediated As phytoremediation in different soil types.

This study provided new insights of economic evaluation and risk assessment in the phytoremediation and mechanisms of compost in biomass production of energy crop at different As concentration. These aspects in phytoremediation studies are imperative to understand for developing safe, cost-effective and soil specific remediation strategies.

摘要

玉米 ( Zea mays L.) 被认为是一种潜在的高产作物，根据土壤类型和土壤中的堆肥施用水平，它可能会对施用堆肥以进行砷 (As) 植物修复做出反应。在这里，我们探索了在温室下不同 As (0–120 mg kg ^-1 ) 和堆肥 (0–2.5%) 水平的两种不同质地土壤（砂壤土和粘壤土）中玉米的堆肥介导的 As 植物修复潜力使适应。结果显示，在没有堆肥的情况下，在不同土壤中生长的玉米植株在不同的砷水平 (0-120 mg kg ^-1 ) 中积累的砷是砂壤土的 1.20-1.71 倍，是粘壤土的 1.20-1.71 倍。土壤中各级堆肥的添加量为 120 mg kg ⁻¹As 在粘壤土中，玉米植株中砷的积累增加了 13%，而在砂壤土中，As 植物吸收量减少了 27%。这可能是由于粘壤土中磷酸盐可提取（生物可利用）土壤砷含量从 2.7 到 3.8 mg kg ^{-1 增加}。估计的每日砷摄入量 (EDI)（0.03–0.15 μg g ^-1体重天^-1）高于美国环保署的标准值。发现玉米植物的砷植物修复潜力对于 1% 堆肥水平的砂壤土和 2.5% 堆肥水平的粘壤土是经济的，这表明堆肥对 As 植物修复计划的土壤类型特定剂量依赖性。

新颖性声明：据我们所知，到目前为止，堆肥在受污染土壤中能源作物的经济可行性方面的作用，特别是在受砷污染的土壤中种植玉米方面的作用尚未得到解决。此外，这是首次评估堆肥介导的砷植物修复在不同土壤类型中的环境和健康风险。

该研究为不同砷浓度下能源作物生物质生产中堆肥的植物修复和机制的经济评价和风险评估提供了新的见解。植物修复研究中的这些方面对于制定安全、具有成本效益和特定于土壤的修复策略至关重要。