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We report results of investigating the processes of electrochemical oxidation of ammonium in a two-chamber electrolyzer depending on the composition of the original solutions ‒ anolyte and catholyte, current density, electrolysis duration. It is shown that the electrochemical oxidation of ammonia in aqueous solutions of ammonium sulfate proceeds at a rate of 14‒55 mg/(dm 3 ·hours) at a current density of 86.2‒172.4 A/m 2 and the starting concentrations of a given ion of 10‒120 mg/dm 3 . The rate of ammonium oxidation under these conditions increases with increasing starting concentrations of ammonium and with increasing current density. The output of oxidized ammonium for current and specific consumption of electricity for water purification from ammonium are defined based on ammonium concentrations and current density and increase with an increase in the concentration of a given ion and a decrease in current density. Ammonium oxidation rate increases by 1.66 times in solutions of ammonium sulfate ([NH 4 + ]=90 mg/dm 3 , j=172.4 A/m 3 ) in tap water, compared with distilled water. This is due to the presence of chlorides in tap water, which act as a catalyst during ammonium oxidation at the expense of the intermediate formation of active chlorine. Under these conditions, we observed complete oxidation of ammonia compared with solutions on distilled water where the residual ammonium concentrations reach 1‒3 mg/dm 3 . It is shown that the presence of chlorides in catholyte at a concentration of 30 mg/dm 3 almost does not accelerate the oxidation of ammonium. Our work demonstrated thatекек in all cases, during oxidation of ammonium, pH of solutions decreases to 6.1‒2.0, which is predetermined by the oxidation of ammonium to nitrates and the acidification of water by the formed nitric and sulphuric acids. Based on the reported results, it can be concluded that the electrochemical method is the most promising method for the extraction of ammonium ions from water. Its application makes it possible to achieve a 100 % water purification.

Исследованы процессы сорбции фосфатов на слабоосновном и сильноосновном анионитах. Установлено влияние формы анионита АВ-17-8 на его емкость по фосфатам в модельных растворах и в водопроводной воде. Изучено влияние сульфатов на селективность ионита по фосфатам. Определены эффективный метод удаления фосфатов из регенерационных растворов хлорида аммония, что делает их пригодными для повторного использования, Among the existing methods for removing the phosphates from water, the most effective and cheap is the method of ion exchange. The advantage of this method is the possibility to process regeneration solutions with obtaining the liquid fertilizers or other useful products.The processes of sorption of phosphates on the weak-base and strong-base anionites are investigated. We examined the dynamics of sorption of phosphates from the model solutions in the distilled and tap water depending on the form of ionite. The influence is established of the competing compounds of sulphates and chlorides in tap water on the effectiveness of removal of phosphate-anions. We explored the processes of regeneration of strong-base anionite in the phosphate and phosphate-sulfate form. The regeneration of anionite in the phosphate form was carried out with the 10 and 15 % solutions of sodium chloride and the 10 % solution of ammonium chloride. In order to regenerate anionite in the sulphate-phosphate form, the solutions of sodium chloride were used at concentration 10 %. The regeneration solutions contained sodium phosphate or ammonium phosphate, sodium phosphate-sulphate, respectively.We established that the effective sedimentation of phosphates occurs at molar ratio (NH4)3PO4 and MgCl2 1:1, at optimum value pH=9. The optimal dosage of magnesium chloride and the value of pH are determined. This will provide 99.99 % sedimentation of phosphates from the regeneration solutions in the form of insoluble sediment. We proposed a method for removal from the regeneration solutions of the interfering compounds of sulphates in the form of gypsum, which will make it possible to repeatedly use these solutions for the regeneration of anionite. The essence of this method is the addition of chloride calcium to the solution, resulting in gypsum falling out into the sediment. The excess of calcium is removed in the form of calcium carbonate when soda is added., Досліджено процеси сорбції фосфатів на слабкоосновному та сильно- основному аніонітах. Встановлено вплив форми аніоніту АВ-17-8 на його ємність по фосфатах у модельних розчинах та у водопровідній воді. Вивчено вплив сульфатів на селективність іоніту по фосфатах. Визначено ефективний метод вилучення фосфатів із регенераційних розчинів хлориду амонію, що робить їх придатними для повторного використання