Water sludge: composition, properties, disposal in wastewater treatment (a review)

Summary

Advanced water treatment schemes are inevitably associated with water sludge generation, the volume of which becomes a separate problem that is comparable to the scale of the actual production of drinking water. In this regard, utilization of water sludge is considered today as a priority task in the research and development in this area. Based on the results of almost thirty years of studies, the main areas of potential use of water sludge have been identified; one of them being water and wastewater treatment. The results of numerous studies evidence the perspectiveness of using water sludge as an adsorbent of phosphates, arsenic, and also heavy metals: Cu, Cd, Cr, Co, Pb, Hg, Zn, Ni, V, Mo, Ga, and Se. Under the conditions of pilot tests, studies were conducted on the extraction of coagulants from water sludge, and on the direct use of water sludge as a coagulant, as well as on its use for enhancing excess activated sludge dewatering. Using water sludge in the foundation of bioengineering facilities, as well as a catalyst for the activation of persulfate and peroxomonosulfate in the destruction of organic micropollutants in the aquatic environment also made good results.

Key words

utilization , toxicity , catalyst , coagulants , water sludge , adsorbent

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UDC 628.349.087.5

IVKIN P. A., KAZAKOV A. V., BELEVCEV A. N., ZHAVORONKOVA V. I., BAJKOVA S. A., MELNIKOVA N. N.

Test of Technology of Galvanochemical Wastewater Treatment for Arsenic Compounds

Summary

The substantiation of perspectivity of application of the galvanochemical method of arsenic removal from wastewater is made. Results of the laboratory study of efficiency of galvanochemical treatment of arsenic-containing model solutions and natural wastewater of an intergrated copper-sulphur plant are presented. It is shown, that application of this technology makes it possible to remove arsenic up to values of Maximum Permissible Concentration (MPC) for water objects. Efficiency and arsenic removal rate depend insignificantly on an initial pH value (in the range of 1,5–9,5). Duration of the galvanochemical treatment ensuring the obtaining of arsenic residual concentrations on a level with MPC depends on its initial concentration in media treated and on a galvanic couple used. The process of arsenic removal progresses with a higher rate when an «iron – copper» galvanic couple is used. When an «iron – crushed coke» galvanic couple is used the duration of treatment necessary for obtaining the arsenic concentration on a level with MPC increases in 2–3 times. Basic flow charts of the galvanochemical treatment of wastewater depending on the initial concentration of arsenic are offered.

Key words

wastewater , arsenic , reagent methods , galvanochemical treatment , toxicity

DOI 10.35776/VST.2021.01.06
UDC 628.166

Ponomarenko A. M., Vlasov Dmitrii, Basov N. S., Novikov S. N., Koudryavtsev N. N., Kostyuchenko S. V.

Experience in introducing UV disinfection of effluents at operating extremely large-scale treatment facilities

Summary

The experience of Mosvodokanal JSC in introducing the technology of effluent disinfection is presented. The paper describes the problem, typical for the Moscow treatment facilities, of ensuring the effluent disinfection in line with the regulatory requirements. The results of long-term experimental-industrial and pilot tests for the UV-disinfection of wastewater after biological treatment carried out at the Kurianovskie wastewater treatment facilities using domestic UV equipment, revealed the high efficiency and stability of disinfection up to the standard requirements under conditions of actual fluctuations in the physical and chemical indicators of wastewater quality. The high efficiency of UV disinfection in relation to specific microorganisms, resistant to chlorination, such as viruses, coliphages, protozoan cysts, has been established. The tests carried out provided for evaluating the effectiveness of UV disinfection and developing a concept for the application of UV disinfection at the Moscow wastewater treatment facilities.

Key words

disinfection , ultraviolet , wastewater , viruses , toxicity , UV-plant , operation experience

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UDC 628.1.032

Chesnokova S. M., Savel'ev O. V.

Estimation of water quality in decentralized water supply sources of Vladimir

Summary

The effect of drinking water chlorination on its organoleptic properties posing a threat to the public health is considered. The water sanitary measurements, the compliance with the requirements to its physiologic adequacy, integral toxicity of the water in the decentralized water supply sources of Vladimir were studied. It was stated that water in all three investigated objects used by the population as alternative drinking water sources was physiologically adequate in relation to the concentration of macroelements and complied with the sanitary chemical requirements of SanPiN 2.1.4.1074-01. As for the concentration of microelements (fluorine and iodine) water in all the investigated objects was not physiologically adequate and did not meet the sanitary and hygienic requirements. The concentration of fluorine in the investigated sources of decentralized water supply and in drinking water of the Nerlinskii water intake varied from 0.1 to 0.3 mg/dm3 what was much less than the lowest limit of the physiologic adequacy and MPC. Iodine in the investigated sources was not detected. In some springs and wells of Vladimir nitrates were detected in concentrations much higher than the MPCs for drinking water. Water in two springs in Vladimir showed hypotoxicity for small crustaceans Daphnia magna Sr. what evidenced the presence in them of trace concentrations of toxic substances hazardous to health.

Key words

potable water , toxicity , physiological full value of water , decentralized water supply source , sanitary chemical indicators

DOI 10.35776/VST.2021.02.03
UDC 574.632/.633

Chesnokova S. M., Savel'ev O. V.

Assessment of the oxygen regime, nitrification processes, trophicity and toxicity levels of minor stream water

Summary

The assessment of the level of pollution and the level of trophicity with nutrients depending on their concentration in a minor stream – the Sodyshka River was carried out. It is shown that in terms of the concentration of ammonium nitrogen and mineral forms of nitrogen, the watercourse throughout its entire length falls in the category «eutrophic»; whereas, in terms of the level of pollution with mineral phosphorus, only some the sections of the river downstream the Yur’evetskaia poultry farm and the mouth can be attributed to the eutrophic category. Permanganate oxidizability and chemical oxygen demand (COD) were used to define the degree of pollution of the watercourse with organic substances of various origin. It is shown that the river is classified as «very dirty» in terms of the total oxidizability (COD). It was found that in 62.5% of water sampling points the oxygen saturation rate (OSR) was below 60% indicating the low quality of water in the stream and low rate of oxidation of organic and inorganic substances in the hydroecosystem. The results of the correlation analysis showed that resistant to oxidation (non-oxidative by microbiota) allochthonous substances have the greatest effect on the degree of water saturation with oxygen (correlation coefficient 0.98). Based on the results of field studies of the concentration of various forms of mineral nitrogen, the intensity of nitrification processes in the river water was calculated. To identify the toxicity of water to zooplankton, zoobenthos, and fish, the aggregation index was used that defined the exceedance of the maximum permissible concentration of the main forms of nitrogen for fishery waters. Judging by the value of the aggregation index, the river water turned out to be toxic.

Key words

toxicity , biogenic elements , permanganate oxidizability , minor stream , oxygen regime , trophicity level , nitrification intensity , correlation dependences

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UDC 628.316.6

SMIRNOV A. D., Bivalkevich A. I., Strelkov A. K., Breslov B. E.

Efficiency and economic expediency of the industrial methods for wastewater disinfection

Summary

Technical and economic assessment of municipal and industrial wastewater disinfection methods is given. At present the method of UV-disinfection with the use of low pressure amalgam lamps is recognized from both technical and economic points of view as a most acceptable method widely used all around the world. UV disinfection ensures most efficient inactivation of pathogenic microorganisms including chlorine-tolerant (viruses) present in effluents. UV irradiation of wastewater is not accompanied with formation of by-products that could produce negative impact on living organisms and human health, i. e. this method is both environmentally and hygienically safe.

Key words

chlorination , ozonization , disinfection , ultraviolet , wastewater , toxicity , amalgam lamp

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