DOI 10.35776/MNP.2020.05.10
UDC 628.169
Kofman V. Ya.
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 628.16.094.3
Kofman V. Ya.
New advanced oxidation technologies of water and wastewater treatment (part 1)
(foreign publications review)
Summary
With the increase in population and industrial water consumption satisfying the demand for drinking water becomes a very pressing issue. This problem can be solved by using innovation process flow schemes of wastewater treatment. Advanced oxidation technologies are among them, i. e. homogenous and heterogenous photocatalytic processes, ozonation, Fenton’s process options, ultrasonic treatment, wet oxidation, electrochemical processes, oxidation in supercritical
water, plasma processes, ferrate and persulfate technologies, ionization radiation and microwave treatment. Hydroxyl radicals play key role in these processes. Photocatalytic processes proceed in the presence of catalysts with titanium dioxide (TiO2) being most efficient among them. The processes proceed in photocatalytic reactors in the presence of suspended catalyst and supported catalyst. In the process of water disinfection the synergistic effect is reached at combining advanced oxidation technologies and chlorination. Fenton’s process is based on the use of Fenton’s reagent, i. e. mixture of Fe2+ salt (catalyst) and hydrogen peroxide. Optimal рН value of 2.8–4 is the basic parameter of this process. Ozonation process proceeding in the presence of hydroxyl radicals originating from chemical transformation of ozone at 2.8 hydroxyl radical reduction potential is considered. Optimal formation of hydroxyl radicals is provided in ozonizers with hydrogen peroxide dosing device (Peroxone process). Ozonation in the process of UV-irradiation; ozonation in the process of UV-irradiation in the presence of hydrogen peroxide, ozonation in combination with ultrasound (Sonozone process) are considered. The use of advanced oxidation technologies in wastewater treatment produces positive results that provide for satisfying the water demand. (To be continued).
Key words
chlorination , ozonization , water treatment , catalyst , oxidation technology , hydroxyl radicals
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UDC 628.16.08
Samsonova S. P., Sergienko A. I., Shalimova E. V., Niakin M. A., Thielemann Joachim
Removal of microbiological pollutants and biofilms from water in water recycling systems of different purpose
Summary
The choice of the technology of inactivation of uncontrolled microbiological activity in the process of water and wastewater treatment has been of primary importance. Microbiological pollutants rank first in the assessment of the risk level for the human health as well as of the risk of economic losses for all the industrial sites having recycled water cooling systems. Water chlorination is the most commonly used method of microorganism control. Drinking water chlorination has been used since 1870-ies and up to the present time; however either this method or any other (boiling, ozonation, ultraviolet irradiation, ultrasound disinfection etc.) do not provide for removing biofilms. The technologies with the use of catalytic units for recycling water treatment are described that provide not only for removing microorganisms from water systems but above all for removing and preventing from further biofilm formation as microorganism life environment. The backbone of the technologies has been the formation on the surface of nonconsumable metal catalyzer of active biotenzides (biological surface-active substances of natural origin that are capable of removing biological pollutants from closed-loop water recycling systems including biofilms on the equipment, pipe surfaces etc. As an illustration of introducing the technologies of catalytic water treatment in water systems the use of units for water purification in the hot water supply systems of Kirovsk, Murmansk Area, with the purpose of eliminating strong offensive odor (cause by the pollution of the hot water supply systems with sulfate reducing bacteria and, correspondingly, by the emission of hydrogen sulfide and mercaptans) is described. The use of catalytic water treatment units provided for eliminating odor in the hot water supply system of Kirovsk to the standards of SanPiN 2.1.4.2652-10.
Key words
catalyst , biofilm , water recycling systems , legionellosis , sulfate reducing bacteria , catalytic water treatment unit
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UDC 628.161.2:546.(711+72)
Zhurba M. G., Savelyev S. P., Ourousov D. Yu., Gabliya Yu. A., Diachuk Sergei, Lykov V. V., Parusov Denis
Improving the technology of deironing and demanganation of the underground waters in Ulyanovsk
Summary
An improved design of two-stage technology of deironing and demanganation of underground waters with the use of floating polystyrene foam media at the Ulyanovsk water treatment facilities was suggested and tested. At the first stage the processes of aeration-degassing, contact filtration and filtration rate regulation of the second stage filters are carried out. It was established that manganese removal from the underground water of Arkhangelsk water intake can be carried out only by additional dosing 0.6–0.8 mg/l of 4–5% potassium permanganate solution before the filters of the second stage. In doing so the time of chemical being in contact with the filter media of the second stage can be reduced from 20 to 4–5 minutes.
Key words
deferrization , ground water , oxidation , demanganization , catalyst , bioreactor filter , floating polystyrene foam media
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