RU2472719C2 - Method of increasing efficiency of aerobic waste water treatment - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention can be used in biological and physical-and-chemical treatment of waste water or in industrial water supply. The method is realised via aeration, sorption and oxidation of contaminants in starting waste water on charge material. The charge material used is dispersed natural schungite mineral which is added at the same time as the waste water to be treated and/or into an aerobic bioreactor. Contaminants are oxidised by dissolved oxygen directly on the surface of schungite and by microorganisms immobilised on the charge material.

EFFECT: high efficiency of treatment.

2 tbl, 2 ex

Description

The invention relates to the field of wastewater treatment by aeration and can be used in biological and physico-chemical wastewater treatment or in the field of industrial water supply.

A known method of aerobic biological wastewater treatment in a bioreactor with immobilized microorganisms. As a load, to increase the efficiency of the aeration process and the microbial oxidation of contaminants in the bioreactor, silica sand, dolomite material, activated carbon, solid coal substrates are used (German Application No. 3917595, class C02F 3/06, 1990).

The disadvantage of this method is the increased costs due to low concentrations of dissolved oxygen due to the use of insufficiently effective downloads, which requires increased energy consumption for additional aeration.

There is also a method of aerobic wastewater treatment, carried out in the presence of a mobile carrier of microorganisms in the form of a porous polymer or copolymer material containing 5-60% activated carbon, with a density of not more than the density supplied to the cleaning liquid with activated sludge, and aeration with an oxygen-containing gas, followed by the removal from the aeration tank of treated water and free activated sludge and the retention of carriers of microorganisms in it, developed by the Ecopolis Scientific Industrial Production Enterprise (Pa ent of the Russian Federation 2039013 C1, C02F 3/08, 1992).

The disadvantage of this method of water purification according to RF Patent 2039013 C1 is the increased cost of the process due to the high content (5-60%) of the mobile carrier of microorganisms in the form of activated carbon and the need for its subsequent separation from the sludge mixture and return to the process.

Closest to the proposed method is a method of aerobic wastewater treatment by sorption and oxidation by immobilized microorganisms in a suspended layer of loading material in the form of coal, clinoptilolite, crushed expanded clay, etc. (RF Patent 2079447, C02F 3/02, 1994).

The disadvantage of the aerobic wastewater treatment method adopted as a prototype is the increased costs for the process as a whole, due to the use of insufficiently efficient and expensive downloads.

The purpose of the invention is to increase the efficiency of the aerobic wastewater treatment process by reducing the cost of aeration.

This goal is achieved by the fact that in the known method of aerobic wastewater treatment, including the supply of wastewater, aeration, sorption and oxidation of contaminants on the feed material, dispersed natural mineral shungite is used as the feed material, which is introduced simultaneously with the treated wastewater and / or aerobic bioreactor, and the oxidation of contaminants is carried out with dissolved oxygen directly on the surface of schungite, as well as microorganisms immobilized on the loading material.

The method is as follows.

Source water containing contaminants is supplied to the aeration zone. Dispersed feed material in the form of natural schungite material is introduced into the feed water or directly into the aeration zone. Sorption and oxidation of contaminants with dissolved oxygen directly on the surface of schungite, as well as microorganisms immobilized on the loading material, are carried out in the aeration zone.

Example 1. Water contaminated with an inorganic compound, sodium sulfite, having a pH of 7.5 and a temperature of 20 ° C, was subjected to purification by aeration in an aerobic reactor with a volume of 300 dm ³ at a water layer height of 0.45 m and air flow Q = 130 l / min the claimed method and the method of the prototype. Water purification from sodium sulfite was carried out at a concentration of feed materials of 1.0 g per 1 liter, with their introduction into the bioreactor.

The process efficiency was assessed by the mass transfer coefficient of oxygen and the cost of the feed material (Table 1).

Table 1 The performance of the wastewater treatment by aeration from inorganic pollution Name The method of wastewater treatment with feed material claimed prototype shungite no download expanded clay clinoptilolite active coal Mass transfer coefficient, hour ^-1 15.61 11.56 7.20 8.17 5.36 Cost of loading, rub / t 32000 - 15,000 24600 85000

The inventive method (table 1) in terms of mass transfer is more efficient than the method with the boot material according to the prototype. The cost of the feed material is higher for expanded clay and activated carbon than for shungite, but lower than for sand. The method with shungite in mass transfer coefficient is 2.17 times more effective than the method of the prototype with expanded clay (15.61 / 7.2). This means that in order to achieve an equal effect with the claimed method, 2.17 times more loading of the prototype is required, i.e. (2.17 × 15000) 32550 rub., I.e. and for material costs, the claimed method is more efficient, which corresponds to the purpose of the invention is to increase the efficiency of the aerobic wastewater treatment process by reducing the cost of aeration.

Example 2. Domestic wastewater after gratings and sand traps having a pH of 7.5 and a temperature of 20 ° C was subjected to treatment in an aerobic reactor with a volume of 300 dm ³ at a water layer height of 0.45 m and an air flow rate of Q = 130 l / min with a concentration biomass of 2 g / l dry matter by the claimed method and the method of the prototype. Wastewater treatment was carried out at a concentration of feed materials of 1.0 g per 1 l when introduced into the source wastewater. The process was evaluated by the amount of dissolved oxygen obtained at a cost of 1 kW × hour of electricity (table 2).

table 2 The amount of oxygen produced in the treatment of domestic wastewater per 1 kW × hour of electricity Name The method of wastewater treatment with feed material claimed prototype shungite no download expanded clay sand active coal Oxygen, kgO ₂ / kW × hour 0.1 0.057 0.050 0.047 0.021 Efficiency (shungite / other material) one 1.75 2.0 2.13 4.77

From the data of table 2 it follows a significant economic efficiency of energy costs for the implementation of the proposed method, which also meets the purpose of the invention.

Claims (1)

A method for aerobic wastewater treatment, including wastewater supply, aeration, sorption and oxidation of contaminants on a loading material, characterized in that dispersed natural mineral shungite is used as a loading material, which is introduced simultaneously with the wastewater being cleaned and / or into an aerobic bioreactor, and pollutants are oxidized by dissolved oxygen directly on the surface of shungite, as well as by microorganisms immobilized on it.