METHOD AND APPARATUS FOR BIOCHEMICAL CLEANING OF SEWAGE WATER CONTAINING Fe²⁺ AND Al³⁺ IONS

摘要

FIELD: processing of industrial sewage waters. SUBSTANCE: method involves performing alkalization of predetermined volume of basic weakly acid sewage water with known content of Fe²⁺ ions to pH value of 7.0-7.5 combined with continuous bubbling with compressed air; introducing catalyst for oxidation of Fe²⁺ ions with atmospheric oxygen; continuing bubbling for another hour; adding coagulant to obtained suspension of mixture of hydroxides of ferric iron and aluminum; separating suspension into liquid and solid phases by known method; directing liquid phase for biochemical cleaning from organic contaminants. Salt of higher oxygen acid of metal or metalloid of VI or VII group of periodic system of elements used as catalyst is taken in an amount of 0.01-0.02% by weight of Fe²⁺ ions. Active slit accumulated during subsequent process of biochemical cleaning of sewage water from organic contaminants is used as coagulant and taken in an amount of 3-5 g/l. Apparatus has two preaerators alternatively operating and used in combination with primary thin-layer settler and combined biofilter-aeration tank and secondary thin-layer settler. Both preaerators have bubblers for supplying compressed air, automatic pH-meters, alkaline reagent and active silt dosers and catalyst solution measuring tanks. Pressure vessel with adjusting valve at lower outlet is positioned above primary thin-layer settler. Funnel with outer diameter of conical part equal to inner diameter of aeration tank is mounted in housing of combined biofilter-aeration tank between filtering member and annular trough for continuous discharge of clean water. EFFECT: increased efficiency in removal of organic contaminants from sewage water by microorganisms of active slit.