Department of Environmental Sciences, COMSATS University Islamabad, Vehari Campus, 61100, Vehari, Pakistan.
Department of Chemistry, College of Science, King Saud University, 11451, Riyadh, Saudi Arabia.
Environ Monit Assess. 2023 Mar 2;195(3):438. doi: 10.1007/s10661-023-11034-x.
Untreated wastewater is routinely used for agricultural activities in water-stressed regions, thereby causing severe ecological risks by various pollutants. Hence, management strategies are needed to cope with the environmental issues related to wastewater use in agriculture. This pot study evaluates the effect of mixing either freshwater (FW) or groundwater (GW) with sewage water (SW) on the buildup of potentially toxic elements (PTEs) in soil and maize crop. Results revealed that SW of Vehari contains high levels of Cd (0.08 mg L) and Cr (2.3 mg L). Mixing of FW and GW with SW increased soil contents of As (22%) and decreased Cd (1%), Cu (1%), Fe (3%), Mn (9%), Ni (9%), Pb (10%), and Zn (4%) than SW "alone" treatment. Risk indices showed high-degree of soil-contamination and very-high ecological risks. Maize accumulated considerable concentrations of PTEs in roots and shoot with bioconcentration factor > 1 for Cd, Cu, and Pb and transfer factor > 1 for As, Fe, Mn, and Ni. Overall, mixed treatments increased plant contents of As (118%), Cu (7%), Mn (8%), Ni (55%), and Zn (1%), while decreased those of Cd (7%), Fe (5%), and Pb (1%) compared to SW "alone" treatments. Risk indices predicted possible carcinogenic risks to cow (CR 0.003 > 0.0001) and sheep (CR 0.0121 > 0.0001) due to consumption of maize fodder containing PTEs. Hence, to minimize possible environmental/health hazards, mixing of FW and GW with SW can be an effective strategy. However, the recommendation greatly depends on the composition of mixing waters.
未经处理的废水通常用于水资源紧张地区的农业活动，从而通过各种污染物对生态系统造成严重风险。因此，需要管理策略来应对与农业废水利用相关的环境问题。本盆栽研究评估了将淡水（FW）或地下水（GW）与污水（SW）混合对土壤和玉米作物中潜在有毒元素（PTE）积累的影响。结果表明，Vehari 的 SW 含有高浓度的 Cd（0.08 mg L）和 Cr（2.3 mg L）。与 SW“单独”处理相比，FW 和 GW 与 SW 混合增加了土壤中 As（22%）的含量，降低了 Cd（1%）、Cu（1%）、Fe（3%）、Mn（9%）、Ni（9%）、Pb（10%）和 Zn（4%）的含量。风险指数显示土壤污染程度高，生态风险极高。玉米在根部和地上部积累了相当数量的 PTE，其生物浓缩系数（BCF）大于 1 的有 Cd、Cu 和 Pb，转移系数（TF）大于 1 的有 As、Fe、Mn 和 Ni。总体而言，与 SW“单独”处理相比，混合处理增加了植物中 As（118%）、Cu（7%）、Mn（8%）、Ni（55%）和 Zn（1%）的含量，同时降低了 Cd（7%）、Fe（5%）和 Pb（1%）的含量。风险指数预测，由于食用含有 PTE 的玉米饲料，奶牛（CR 0.003>0.0001）和绵羊（CR 0.0121>0.0001）可能存在致癌风险。因此，为了最大限度地减少潜在的环境/健康危害，可以采用将 FW 和 GW 与 SW 混合的策略。然而，该建议在很大程度上取决于混合水的组成。
