The article presents the developed anaerobic-aerobic wastewater treatment technologies. These technologies aimed at removing the organic matter, nitrogen and phosphorus by means of microorganisms immobilized on fibrous carrier surfaces. The results of the laboratory research show the high efficiency of milk wastewater treatment. The following degrees of reduction were achieved for the pollutant indicators: COD -86.7-93 %, total nitrogen - 96.9-97.9 %. Compared to the traditional treatment technologies applied in Ukraine, these values are high. The concentration of organic matters and biomass of not attached bacteria decreased in bioreactor chambers. When the purification process ends, a small amount of excess biomass remains; therefore, its self-oxidation and self-regulation occurs as a result of consumption by the organisms occupying higher levels of trophic chains. The use of anaerobic-aerobic bioreactors system for the treatment of wastewater enables achieving high outflow quality and prevents the suspended substances from slipping. Immobilization of microorganisms on the first stage of the technology prevents the formation of big amount of excessive sludge and removes biomass from the bioreactor, which allows the technology even for the heavily polluted wastewater. In reactors containing immobilized microorganisms, the organic matter compounds used in subsequent reactors for phosphate accumulation are split. The presented biotechnology saves electric energy, provides sufficient quality of treatment, and ensure the compliance of treated wastewater with the effluent standards.

No abstract

No abstract

Even after using physico-chemical and biological methods, tannery wastewater still contains a large amount of nitrogen compounds, which reaches 90 mg/dm3. The ingress of such wastewater into natural reservoirs leads to eutrophication. The goal is to determine the efficiency of nitrogen compounds removal during sequential wastewater treatment in anaerobic, anoxic and aerobic bioreactors with immobilized microorganisms. For the study, wastewater from a tannery, collected after cleaning in aeration tanks, was used. Model solutions with a concentration of 18.4 - 90 mg/ dm3 were obtained by dilution. 5 sequential bioreactors were used - anaerobic (2 stages), anoxic (2 stages) and aerobic (1 stage) with a capacity of 125 ml/h. Microorganisms were immobilized in each bioreactor on artificial carrier. The effects of organic nitrogen removal in anaerobic bioreactors were 58-66%, anoxic 51-70%, aerobic 57, 5%. A decrease in the concentration of nitrogen compounds occurs as a result of the formation of N2, NH3 gases and the use of nitrogen by microorganisms for biomass growth. It is proposed that sequential treatment of tannery wastewater in anaerobic, anoxic, and aerobic conditions with immobilized microorganisms made it possible to obtain a high degree of nitrogen removal. The method does not require chemical materials and is ecological.

The technology of local wastewater treatment of oil production is presented. It based on the consistent use of physico-chemical treatment methods and allows to remove organic matter, suspended solids from wastewater to the requirements of regulations and divert treated wastewater into the municipal sewerage system. Wastewater generated during the processing of soapstocks, in terms of pollutants exceeds the standards set for wastewater when discharged into urban drainage systems. Therefore, before removal to municipal treatment facilities, they must be treated locally using physico-chemical and biological methods. In the phase-dispersed state, such wastewater is a stable emulsion. The presence of phospholipids, which are stabilizers of emulsions, complicates the phase separation of wastewater components. In addition, wastewater contains suspended particles, colloidal and dissolved substances of organic and inorganic nature. It was found that the highest values ​​of the effect of removal of organic matter by COD - 78% at the initial COD - 40000 mg / dm3, the effect of reducing the concentration of suspended solids - 72.5% at the initial 6300 mg / dm3 were obtained in the process of coagulation using Al2 (SO4)3 and subsequent flotation with air supply through porous materials. The technological scheme of local treatment of industrial wastewater is proposed. It includes the following main processes: averaging, aeration, alkalinization, coagulation, flotation, oxidation, filtration, adsorption. Experimental studies have shown the effectiveness of treatment of soapstocks in oil production using the proposed technology with bringing the quality of treated wastewater to current sanitary requirements, which allowed to recommend the technology of treatment of soapstocks for successful use in industrial enterprises of the oil industry.

An improved technology for the local treatment of industrial wastewater of a meat processing plant is proposed for the intensification of cleaning processes and an increase in the efficiency of local treatment of industrial wastewater of a meat processing plant according to the indicators: HSC, SPAR, phosphates, ammonium nitrogen, fats, and obtaining purified water in accordance with regulatory requirements at discharge into the city sewer. According to the proposed technology, industrial wastewater after the existing grease trap and concentrator is pumped to reactive flotation using an alkaline reagent and coagulant - aluminum sulfate, with the production of coagulant flakes as a result of coagulation, removal of pollutants from water and separation of phases in the form of flotation sludge and sediment and purified water with quality indicators in accordance with regulatory requirements. The flotation sludge formed during wastewater treatment is diverted to a collector and taken away, and the sediments are recommended to be dewatered on a filter press and taken away. On the basis of the performed experimental studies, it was established that when aluminum sulfate is used as a coagulant at a dose of 250-300 mg/dm3 at a pH of 7-7.5, the effects of cleaning industrial wastewater of a meat processing plant are: water - 460-670 mg/dm3; suspended substances - 90-95%, the content of suspended substances in purified water - 10-23 mg/dm3; SPAR - 88%, SPAR content in purified water - 0.43-0.08 mg/dm3; phosphates - 62-65%, phosphate content in purified water - 3.6-5.4 mg/dm3; ammonium nitrogen - 40-42%, ammonium nitrogen content in purified water - 15.3-17.0 mg/dm3. An improved technology for local treatment of industrial wastewater using coagulation and flotation methods has been developed, the implementation of which will allow obtaining high-quality purified water, the indicators of which meet the regulatory requirements for the discharge of wastewater into the drainage system of the city of Kharkiv.

No abstract

Industrial wastewater from the oil and fat industry contains a variety of pollutants that pass into wastewater during processing of soapstocks: fats and fatty acids and their salts (aqueous soap solutions), glycerin, phosphoglycerides, neutral fat, phosphatides, proteins, carbohydrates dyes (carotene, carotenoids, chlorophyll, etc.), unsaponifiable and waxy substances, salts - sodium sulfate and chloride, mechanical impurities, etc. Soapstocks have a complex and volatile composition, which depends on the nature and properties of its components, the amount of fat-related substances in it. The effect on alkaline reagents and coagulant reagents on co-stocks is proposed and investigated. The obtained results allow to establish rational doses of reagents for effective removal of pollutants from soapstocks. In the studied wastewater, the concentration of organic matter according to the HSC was 40,000 mg / dm3, low pH 2, at which the stability of the state of organic pollutants in the water (no foaming, sedimentation). Calcium carbonate and sodium hydroxide solutions were used as alkalizing reagents. Comparison of the effects obtained under the action of calcium carbonate, compared with the effects obtained with sodium hydroxide, showed 2.4-2.5 times greater efficiency for HSC. The effects of removal of suspended solids and organic substances by HSC at a dose of aluminum sulfate 2 g / dm3 were, respectively, 85.6% and 72% when providing a pH of 5.5 by the action of calcium carbonate. However, it is not possible to remove organic matter to acceptable values ​​when discharged into the city sewer in one stage of purification. Therefore, both after alkalization with calcium carbonate and after coagulation with aluminum sulfate, it is proposed to use the flotation method of phase separation, for example, using air supply through porous materials.