Stasiuk S. Improvement of groundwater defferization technologies in agricultural water supply systems

Agricultural water supply, especially for local water pipelines, is based on the use of groundwater, which has better protection against contamination from soil surface. Groundwater at the depths of 60-150 m in the northern regions of Ukraine (more than 50% of the explored reserves) has a high iron content, which is sometimes tens of times higher than the permissible norms (0.2 mg/dm3). This requires the construction and operation of defferization installations for local agricultural water pipelines, which are required to reliably provide all consumers with quality water in sufficient quantities and under the required free pressure at the lowest cost for construction and operation of waterworks. During the implementation of this idea, a compact installation, which takes up little space and can be placed in pumping stations or other production facilities under the roof, was developed. Utility model patent was obtained for the imstallation. To determine the optimal design and technological parameters of such an installation, laboratory studies of water defferization processes at three speeds of ascending filtration of aerated water through the contact-clarifying filter (CCF) were carried out: 7; 9 and 11 m/h for two methods of oxidation of ferrous iron: physico-23chemical (without bioreactor); biological (with the help of ferrobacteria on the fibrous loading of bioreactor). Comparison of physicochemical and biological methods of groundwater defferization has shown significant advantages of the biological method, as it increases the efficiency of water defferization installation (E), increases the duration of the filter cycle (Tf), sediment amount (∆G) retained during this period, simplifies operation, and improves its technical and economic performance. The necessary engineering calculations have been performed and recommendations for the design and operation of iron-removing installations have been developed. The feasibility study has been performed and implemented into production.