State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
Int J Environ Res Public Health. 2019 Sep 3;16(17):3218. doi: 10.3390/ijerph16173218.
Wastewater irrigation is widely practiced and may cause serious environmental problems. However, current knowledge on the effects of long-term irrigation with wastewater from different sources on the biouptake of trace metals (TMs) in the rhizosphere zone by plants in farmlands is limited. Here, we analyzed wheat rhizosphere soil and wheat roots collected from a typical wastewater irrigation area in North China to evaluate the influence of wastewater irrigation from different sources on the bioavailability of trace metals in soils. Results showed that irrigation with tanning and domestic wastewater helped enhance the bioavailability of trace metals in rhizosphere soil by increasing the active organic carbon content, soil redox potential, and catalase activity, thus enhancing the proportion of the potentially bioavailable part of trace metal speciation. Conversely, irrigation with pharmaceutical wastewater can reduce the bioavailability of trace metals in rhizosphere soil by increasing total soil antibiotics and thus decreasing the proportions of bioavailable and potentially bioavailable parts of trace metal speciation. These findings can provide insights into the migration and transformation of trace metal speciation in soil rhizosphere microenvironments under the context of wastewater irrigation.
污水灌溉被广泛应用，但可能会导致严重的环境问题。然而，目前对于不同来源的污水长期灌溉对农田根际区植物对痕量金属（TMs）生物吸收的影响的了解有限。在这里，我们分析了来自华北典型污水灌溉区的小麦根际土壤和小麦根，以评估不同来源污水灌溉对土壤中痕量金属生物有效性的影响。结果表明，制革和生活污水的灌溉通过增加活性有机碳含量、土壤氧化还原电位和过氧化氢酶活性，提高了痕量金属形态中潜在生物有效部分的比例，从而增强了根际土壤中痕量金属的生物有效性。相反，医药废水的灌溉可以通过增加土壤中抗生素的总量来降低根际土壤中痕量金属的生物有效性，从而降低痕量金属形态中生物有效和潜在生物有效部分的比例。这些发现可以为了解在污水灌溉背景下土壤根际微环境中痕量金属形态的迁移和转化提供深入的认识。
