Title : Restoration of water resources for sustainable agriculture: reuse of wastewater and groundwater
Abstract:
This presentation covers a comprehensive scientific and practical study aimed at developing a two-stage technology for the effective monitoring, neutralization, and subsequent reuse of heavy metal ions and other chemical pollutants occurring in industrial wastewater and exploited groundwater sources in both agriculture and industrial enterprises. In recent years, as a result of global climate change, accelerated industrialization, and the intensification of technogenic processes, the concentrations of heavy metal ions such as Zn²?, Pb²?, Cu²?, and Cr³? in groundwater and wastewater have been steadily increasing. This situation has been exerting adverse effects on soil fertility, plant physiological processes, and human health. In this regard, our research proposes a scientifically substantiated method for water purification.
At the first stage, the pH of the aqueous medium is increased, and heavy metals are precipitated using alkaline reagents such as ammonia, potassium hydroxide, or calcium hydroxide. Under highly alkaline conditions, dissolved metal ions transform into poorly soluble hydroxide precipitates, which are subsequently removed through filtration or sedimentation processes. In the second stage, the treated water is neutralized using sulfuric and nitric acids, adjusting the pH to an optimal range. As a result, the acid–base balance of the water is stabilized while, simultaneously, beneficial nutrient compounds such as NH?NO?, KNO?, and K?SO? are formed.
Thus, the proposed technology not only eliminates hazardous metal ions but also converts the purified water into an agriculturally valuable resource, enabling its use as irrigation water with fertilizing properties. During the research process, comparative analyses were conducted among control samples, water subjected only to alkalization, and water treated through the full two-stage process. Parameters such as pH, total mineralization, concentrations of major cations and anions, residual heavy metals, and effects on plant growth were investigated under laboratory conditions. Furthermore, the technology was tested in small-scale pilot units, where energy consumption, material balance, and the cost of treating 1 m³ of water were determined.
The scientific novelty of the study lies in the integrated processing approach that combines high-pH metal precipitation with an agro-beneficial neutralization stage, ensuring both environmental protection and resource-efficient agricultural development. The expected outcomes include the creation of a practical technology that promotes sustainable water resource utilization, reduces technogenic pollution, improves the agrophysical and agrochemical properties of soils, and ultimately contributes to increased crop productivity
