Application of Acid-Actived Zeolith in the Technology of Cleaning Wastewater from Nitrates

Abstract

The deterioration of the quality of water from surface sources occurs as a result of their constant contamination by substances of anthropogenic origin: biogenic elements, petroleum products, surface-active, organic and other substances, which is associated with insufficient depth of sewage treatment. At present, an increase in the degree of wastewater treatment from biogenic elements to an environmentally safe indicator is an actual scientific and technical task. Despite measures and methods used for wastewater treatment, pollutants continue to enter water bodies and the removal of nutrients from wastewater is required because the compounds of Nitrogen and Phosphorus cause the process of eutrophication of reservoirs. From the total number of possible technological solutions for improving the degree of sewage treatment, one of the most promising is the use of zeolite as a sorption material. This mineral allows 1.5-2 times to improve the purification of waste water from nitrate ions (NO₃^-) compared with the traditional chemical-biological method. The purpose of this work is to carry out an experimental study of adsorption release of ions NO₃^- from urban and industrial waste water of Kamyanske city using natural zeolite and zeolite activated by chloride acid. It has been experimentally established that the use of an acid-activated zeolite with a dose of 2 g/dm³ for a contact time of 120 minutes provides a reduction in the nitrate concentration from 500 mg/dm³ to 96 mg/dm³, in the case of coke wastewater; as a result of treatment of domestic wastewater with an acid-activated zeolite with a dose of 2 g/dm³, the concentration of NO₃^- ions decreases from 30.5 mg/dm³ to 14.7 mg/dm³. In the latter case, the normative concentration of nitrate ions in water of centralized water supply systems is achieved in accordance with DSTU 7525-2014.