E. A. Karpychev

Bio: E. A. Karpychev is an academic researcher from Ivanovo State Power University. The author has contributed to research in topics: Environmental chemistry & Chemistry. The author has an hindex of 1, co-authored 4 publications receiving 10 citations.

Improvement of water treatment at thermal power plants

Abstract: Prospective and existing technologies for water treatment at thermal power plants, including pretreatment, ion exchange, and membrane method are considered. The results obtained from laboratory investigations and industrial tests of the proposed technologies carried out at different thermal power plants are presented. The possibilities of improving the process and environmental indicators of water treatment plants are shown.

An analysis of and ways for improving the performance of the pretreatment facilities used in the water treatment plant at the TETs-5 cogeneration station of the Kirov Branch of OAO TGK-5

Abstract: Results from an analysis of the performance of the water pretreatment plant used at the TETs-5 cogeneration station operated by the Kirov Branch of OAO TGK-5 and from tests of clarifiers under the conditions of the existing technology are presented. Data obtained from laboratory studies of the properties of flocculants under local conditions are presented and their efficiency is estimated.

A study and selection of conditions for coagulating water at OAO Severstal’s cogeneration station

Abstract: Laboratory studies on determining the efficiency of purifying low-mineralized water with an increased content of organic substances by means of different coagulants and flocculants are carried out. The best results are obtained for aluminum hydroxychloride and aluminum sulfate with adding small quantities of type 2520TR flocculant produced by Ashland and AN-910 PWG flocculant produced by SNF. Results obtained from industrial tests carried out in a horizontal plate-type clarifier are presented.

Determination of sorption characteristics of aluminum hydroxide sludge formed at the stage of pre-purification of water treatment plant

Abstract: An urgent task of the research is to describe the properties of the sludge formed during coagulation depending on the type of water supply source. Namely, the aim is to study the sorption capacity of the sludge for the main components removed from the water (iron compounds, organic substances, and silicic acid compounds). This indicator allows you to directly determine the effectiveness of the coagulation. When comparing the actual values of this indicator with practically obtainable values, one can say about the lack or excess of the coagulant supplied for processing. To calculate the specific sorption capacities of the sludge, the following indicators have been used: organic content, the weight concentration of silicic acid compounds in terms of SiO2 and the weight concentration of iron compounds in terms of Fe. After drying and calcining the sludge, the resulting mineral residue has been dissolved in the solution, and the content of the final components was determined. Conventional water analysis methods have been applied. For the first time, a method is proposed to determine the specific sorption capacities of aluminum hydroxide sludge for organic compounds, for iron compounds in terms of Fe, for silicic acid compounds in terms of SiO2. A classification of natural low-turbidity waters with an increased content of iron-organic compounds is proposed. Within the framework of the proposed classification of waters, the authors have obtained previously undetermined actual specific sorption capacities of the sludge. Recommendations have been given to get practical importance values of the sorption characteristics of the sludge. The proposed method to calculate the sorption capacity of aluminum hydroxide sludge and index of sorption capacity of the sludge are recommended to be used as a parameter that determines the conditions and efficiency of application of the aluminum sulfate coagulation technology. Excessive doses of the coagulant that provide a sorption capacity of the sludge greater than the recommended values, lead to an excessive consumption of both the reagent itself and purge water. Thus, some measures can be taken to bring the sorption capacity of the sludge to practically achievable values, for example, aquatic acidification.

Improvement of water treatment at thermal power plants

Abstract: Prospective and existing technologies for water treatment at thermal power plants, including pretreatment, ion exchange, and membrane method are considered. The results obtained from laboratory investigations and industrial tests of the proposed technologies carried out at different thermal power plants are presented. The possibilities of improving the process and environmental indicators of water treatment plants are shown.

Computational-Experimental Verification of Technologies of Utilization of the Concentrate Formed in the Reverse-Osmosis Water Demineralization Cycle

Abstract: Technologies for utilizing the wastewater of the reverse-osmosis plants (ROPs) to prepare the make-up water for power-generating plants of combined heat and power plants and nuclear power plants are proposed and substantiated using mathematical models and full-scale experiments. The ROPs use natural feedwater with a wide range of quality characteristics. For the first time, variants of the treatment of the concentrate formed in the ROP cycle have been proposed for the reuse of the latter by acidifying it in H-type cation- exchange filters charged with a weakly acidic cation-exchange resin. By admixing part of the filtrate processed in the H-type cation-exchange filters to the feedwater, the latter is acidified thus reducing the probability of formation of carbonaceous sediments and water consumption. The rest of the filtrate subjected to a conversion process is used as a constituent of the make-up feedwater of the heating system or potable water, which eliminates the discharge of the reverse-osmosis plant wastewater into the environment. Another feature of the proposed technology is that the H-type cation-exchange filters are integrated into a regenerant solution reuse circuit (RSRC). As a result, the consumption rate of sulfuric acid for regeneration equals the stoichiometric rate and the regeneration yields gypsum used to produce a binding agent for construction. The kinetics of separation of gypsum from the spent regenerant solutions with different chemical compositions was studied experimentally as applied to the RSRC conditions. The procedure of operating filters charged with the Lewatit CNP-LF cation-exchange resin was trialed under production conditions. It was established that the height of the filtering cation-exchange resin layer should be 1.0–1.5 m and the concentration of the regenerant solution should not exceed 0.8% at a rate of 10–15 m/h. The basic components of the technological scheme were trialed under production conditions on a water treatment plant in service.

Membrane Capacitive Deionization for Cooling Water Intake Reduction in Thermal Power Plants: Lab to Pilot Scale Evaluation

Abstract: Cooling of thermal power stations requires large amounts of surface water and contributes to the increasing pressure on water resources. Water use efficiency of recirculating cooling towers (CT) is often kept low to prevent scaling. Partial desalination of CT feed water with membrane capacitive deionization (MDCI) can improve water quality but also results in additional water loss. A response surface methodology is presented in which optimal process conditions of the MCDI-CT system are determined in view of water use efficiency and cost. Maximal water use efficiency at minimal cost is found for high adsorption current (2.5 A) and short adsorption time (900 s). Estimated cost for MCDI to realize maximal MCDI-CT water use efficiency is relatively high (2.0–3.1 € m−3evap), which limits applicability to plants facing high intake water costs or water uptake limitations. MCDI-CT pilot tests show that water use efficiency strongly depends on CT operational pH. To allow comparison among pilot test runs, simulation software is used to recalculate CaCO3 scaling and acid dosage for equal operational pH. Comparison at equal pH shows that MCDI technology allows a clear reduction of CT water consumption (74%–80%) and acid dosage (63%–80%) at pH 8.5.

Water-Chemistry and Its Utility Systems in CCP Power Units (Review)

Abstract: Damageability of heat transfer surfaces of waste heat recovery steam generators (HRSG) of combined- cycle plants (CCP) can be reduced due to an increase in the quality of make-up and feed water, the use of phosphate-alkaline or amino compound water chemistry (WC), and improved chemical quality control of the heat carrier and make-up water preparation techniques Temporary quality standards for the heat medium developed by the All-Russia Thermal Engineering institute (VTI) for CCP power units are presented in comparison with the IAPWS standards; preferences for the choice of a WC type for some power units commissioned in Russia in the first decade of this century are shown; and operational data on the quality of feed, boiler water, and steam for two large CCP-450 and CCP-425 power units are given The state and prospects for the development of chemical-technological monitoring systems and CCP water treatment plants are noted Estimability of some CCP diagnostic parameters by measuring specific electric conductivity and pH is shown An extensive bibliography on this topic is given