Development of a new technological scheme for water purification from iron

Abstract

Drinking water is the most valuable resource for human life and for the existence of all life on Earth. Scientists predict that about half of the world's population will experience water shortages by 2030. Purification of fresh water from contamination to the required quality standards is one of the most demanded engineering tasks. Taking into account the prevailing hydrogeological conditions, the removal of dissolved iron from the water of underground horizons is more in demand. Iron removal technology includes the use of oxidizing agents: oxygen, chlorine, potassium permanganate and ozone. It is ozone, due to its high oxidizing potential - 2.07 V, that has become worldwide in industrial water treatment systems, where it is generated using a corona discharge. But in water purification systems of low productivity, up to 1000 l / h, ozone is practically not used, due to the high cost of such generators. The Sterlight S8Q-OZ lamp was proposed as an alternative for ozone generation. According to the manufacturer's data, the lamp can produce ozone in a concentration of 1.59 to 2.82 mg / l when an air flow of 141.5 to 28.3 liters per hour passes through it. A new technological scheme was developed for deferrization of water in a stream using ozone generated by an ultraviolet lamp or a block of lamps. The installation contains an injector, an improved mixing chamber with a bottom inlet of the ozone-air mixture with Pall rings, a sand-gravel filter, an ultraviolet sterilizer lamp. The design feature was that small doses of ozone produced from the air under the influence of ultraviolet radiation with a length of 185 nm oxidized the iron dissolved in water. As a result of the tests carried out, the iron content in the source water was reduced from 2.58 mg / l to 0.02 mg / l, which is 10.0 times lower than the maximum permissible values of the EU sanitary requirements and 15.0 times lower than the maximum permissible values of sanitary requirements of the Russian Federation and the USA. It has also been noted that iron oxidation is significantly improved in the presence of 10% STIROX catalyst based on total backfill.