Davand Hiva, Sepehr Ebrahim, Momtaz Hamid Reza, Ahmadi Fatemeh
Department of Soil Science, Faculty of Agriculture, Urmia University, Urmia, Iran.
Department of Soil Science, Faculty of Agriculture, Urmia University, Urmia, Iran.
Sci Total Environ. 2022 Dec 10;851(Pt 1):158180. doi: 10.1016/j.scitotenv.2022.158180. Epub 2022 Aug 23.
Wastewater, an alternative supply of water and nutrients, is being allocated as a priority for human population sustainability in arid and semi-arid regions. This work proposes phosphorus (P), a vital growth-limiting nutrient, adsorption behavior in wastewater irrigated agricultural soils in comparison to non-irrigated soils using laboratory batch experiments. The adsorption mechanism was assessed using different adsorption isotherm models. Saturation indices were modeled, using the hydro-geochemical transport code PHREEQC and MINTEQ geochemical software. Phosphorus buffering parameters were also calculated based on the standard equations. The equilibrium data were well fitted with the Freundlich isotherm model. The physical adsorption mechanism was found based on the calculated isotherm parameters. The maximum adsorption capacity was two times more in non-wastewater irrigated soils than irrigated. Results highlighted the effectiveness of wastewater irrigation in P availability in soil. Based on the PHREEQC modeling data, precipitation of Pb and Zn mineral phases was probable in soils by wastewater influence. Meanwhile, the precipitation of stable calcium phases, that affect the P sorption and/or co-precipitation, in non-wastewater irrigated soils was highlighted in the PHREEQC calculations. The standard buffer capacity (SBC) was 43 and 64 L kg in wastewater irrigated soils and non-irrigated soils, respectively. Findings of the present study demonstrate the importance of wastewater reuse opportunities for agricultural application, especially soil P availability, and are helpful to minimize the environmental impacts of wastewater and solid waste.
废水作为水和养分的替代来源，正被视为干旱和半干旱地区人类可持续发展的优先资源。本研究通过实验室批量实验，比较了废水灌溉农业土壤与非灌溉土壤中磷（P）这种重要的生长限制养分的吸附行为。使用不同的吸附等温线模型评估吸附机制。利用水文地球化学传输代码PHREEQC和MINTEQ地球化学软件对饱和指数进行建模。还根据标准方程计算了磷缓冲参数。平衡数据与Freundlich等温线模型拟合良好。根据计算得到的等温线参数发现了物理吸附机制。非废水灌溉土壤的最大吸附容量是废水灌溉土壤的两倍。结果突出了废水灌溉对土壤中磷有效性的作用。基于PHREEQC建模数据，废水的影响可能导致土壤中铅和锌矿物相的沉淀。同时，PHREEQC计算突出了非废水灌溉土壤中稳定钙相的沉淀，这会影响磷的吸附和/或共沉淀。废水灌溉土壤和非灌溉土壤的标准缓冲容量（SBC）分别为43和64 L/kg。本研究结果表明了废水再利用在农业应用中的重要性，特别是对土壤磷有效性的影响，有助于减少废水和固体废物对环境的影响。
