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UDC 628.336.098.4
Danilovich Dmitrii, Vanyushina A. Ya.
Anaerobic digestion – the key technology of municipal wastewater sludge treatment (part 2)
Summary
The technologic options of municipal wastewater sludge treatment are reviewed with different approaches to stabilization of organic matter. The technologic and environmental consequences of raw wastewater sludge landfilling are described. Aerobic sludge stabilization processes are considered. It is concluded that their use is restricted to the options when land utilization of the entire sludge volume is possible. It is shown that traditional aerobic stabilization that was widely used last century does not meet the present day requirements both to power consumption and organics decomposition depth. The aspects of the domestic approach to digestion that consist in using thermophilic mode with extremely low retention time of sludge in a digester are considered. The ways of solving these problems at the Kouryanovo and Lyubertsy wastewater treatment facilities in Moscow are described. It is concluded that in the XXI century anaerobic digestion of wastewater sludge in digesters does not have any other comparable alternative for large and mid-sized wastewater treatment facilities. The main trends in using digestion process, digester design, methods of enhancing the process are considered. The information on biogas properties is consolidated and various options of its utilization are reviewed. Process flow schemes with the use of digesting and combining with other sludge treatment processes (drying, incineration), methods of digested sludge utilization are considered. The information on environmental aspects of digestion – reducing greenhouse gas emissions and carbon footprint – is given. The technologies of purification of return flows of digested sludge dewatering are described. The advanced sludge treatment flow scheme based on digestion and recommended for large-scale facilities is given.
Key words
anaerobic fermentation , sludge , nitrogen , phosphorous , return flows , methane tank , stabilization , biogas utilization , energy budget
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UDC 628.35:316.12
Kofman V. Ya.
Extraction of nitrogen and phosphorus in the form of struvite from wastewater with high nutrients concentration
Summary
The world reserves of phosphate ore total about 7000 mln tons among them 40 mln tons are used annually in fertilizer production. It is estimated that this resource will be depleted by 2090. In this connection exploring alternative renewable phosphorus sources is a critical task; therefore much attention is paid to developing economical and technically available methods of phosphorus extraction together with nitrogen from different wastewater types; one of the methods being nutrients precipitation in the form of struvite (MgNH4PO4·6H2O). Studies of struvite production from wastewater and its use as a fertilizer have been carried out in many countries of the world. Process schemes of struvite extraction from municipal wastewater, steel making and tanning wastes, coking process effluents, solid waste landfill filtrate, livestock and dairy farm wastewater as well as from black wastewater in the process of its decentralized processing have been developed. Studying the use of struvite as a fertilizer has been carried out almost 20 years already. Generally the prospects of investing in the production of this product for the agricultural sector are not disputed. The practice of production and supply of struvite as a fertilizer has been fairly developed in Japan. The application of struvite does not result in the increase of heavy metal concentration in farm crops. Fast dissolving fertilizers are not efficient when used on pastures or in forests where fertilization is practiced every few years. In this context the use of slowly dissolving fertilizers including struvite is more reasonable.
Key words
wastewater , nitrogen , phosphorous , struvite , filtrate of solid waste landfills , phosphatic fertilizers
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UDC 504.06
Skryabin A. Yu., Popovian G. V., Tron' I. A.
Study of the factors effecting the intensive growth of microalgae in the Don River
Summary
The factors enhancing the growth and evolution of the microalgae species composition in the Don River were studied. The effect of phosphorus on the phytoplankton growth rate was proved. The sources of nutrients incoming to the water bodies were analyzed. The factors of anthropogenic eutrophication of water bodies are presented: dyke construction facilitating the reduction of the river flow rate; decay of the vegetation on the lands immersed during the construction of water reservoirs and canals; intensive development of industrial production, agricultural activities, cattle breeding; increase of household and industrial use of synthetic detergents. The strategy of controlling water source bloom is proposed: bloom suppression during its development directly in the water body; the use of biological treatment methods (rehabilitation of the natural biocenosis by seeding certain microalgae species – different Chlorella strains and some species of herbivorous fish, e.g. silver carp; elimination of household and industrial use of phosphorus-containing detergents and their replacement with phosphate free detergents; strengthening of control of nitrogen and phosphorus fertilizer use in agriculture; construction and stepwise reconstruction or upgrade of wastewater treatment facilities that provide for enhanced removal of nitrogen and phosphorous compounds.
Key words
water supply , odor , nitrogen , phosphorous , phytoplankton , microalgae , geosmin , odor components , surface water source
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UDC 628.35:661.5.63
KOZLOV M. N., Moyzhes O. V., Nikolaev Yu. A., GRACHEV V. A., Kevbrina M. V., Dorofeev A. G., Aseyeva V. G.
M-Defanox – multisludge system of nutrient removal
Summary
M-Defanox new technology was developed for the treatment of municipal wastewater low in organics. The method is based on the use of three sludge types and dephosphorization under anoxic conditions. The technology provides for the efficient utilization of organics in biological treatment process and ensures 99% nitrogen removal, 80% phosphorus elimination, 80% COD removal and 95% BOD removal.
Key words
wastewater , biological treatment , nitrogen , phosphorous , activated sludge , biogenic elements
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UDC 628.35: 661.5.63
Ospanov K. T., Elzhasov A. A.
Sewerage Treatment Facilities of the City of Astana (Kazakhstan)
Summary
The flow chart of biological treatment of municipal wastewater making it possible to increase the efficiency of removal of phosphorous compounds equally with the efficient removal of nitrogen compounds is offered. Advantage of this technology is possibility of reconstruction and modernization of operating treatment facilities with the maximum use of existing capacities. The technique of nitri-denitrification with a dephosphatation chamber is used at the operating facilities of the city of Astana. Zeolite of the Chankanayskoye deposit is used as a media. Zeolite intensifies the processes of advanced biological treatment of wastewater both for organic pollutants and biogenic elements.
Key words
sedimentation tank , suspended substances , wastewater , biological treatment , nitrogen , phosphorous , aeration tank
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UDC 628.35:661.5.63
Trunov P. V., Lunin S. V., Chuev E. V., Pavlova V. Yu.
Enhancement of Efficiency of Biological Removal of Nitrogen and Phosphorus Compounds at Sewerage Treatment Facilities
Summary
The technology of wastewater treatment for biogenic elements using the processes of nitri-denitrification and dephosphatization on the basis of up-to-date sewerage treatment facilities is described. The principle of computer simulation with the help of the program complex BioWin is the basis of technical decisions. The aim of this calculation is to achieve reliable results which can be used in practice. The main advantages of introduction of high effective, ecologically safe technologies of waste water treatment using the equipment manufactured by the scientific and production firm Ekoton are described. Stages of the main works made by the engineering department of the company which can become a base for the beginning of design preliminary studies and receiving of necessary investments are considered.
Key words
biological treatment , nitrogen , phosphorous , nitri-denitrification , dephosphatization , simulation of treatment processes , Optimizing calculation
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UDC 628.35
Matуushenko Evgeny, Gundyreva Tat’iana
Improving the efficiency of wastewater treatment facilities with chemical phosphorus removal from reject water
Summary
The problems associated with the eutrophication of water bodies receiving effluents containing phosphorus in residual concentrations are described. The reasons for the most intensive phosphorus release into the intrasite sewage system during sludge processing are given. It has been established that the discharge of this wastewater into the head structures of wastewater treatment facilities leads to an increase in the nutrients loading (nitrogen and phosphorus), suspended solids, COD. The results of experimental studies on the selection of the optimal type and dosage of the chemical for the removal of phosphates from reject water generated during municipal wastewater sludge treatment are given. The purpose of the research is to find ways to remove phosphorus to eliminate the increase in phosphorus concentration in the receiving chamber observed as a result of reject water discharge from the sludge treatment facilities, and to ensure the wastewater treatment of the intrasite sewage system of the treatment facilities with minimal construction and operating costs as well as to produce reusable sludge. A process flow scheme of the nutrients removal from the wastewater of intrasite sewage system of the treatment facilities of Novosibirsk is proposed. The process provides for the sludge that after stabilization and decontamination can be used as organic fertilizer for industrial crops.
Key words
filtrate , wastewater , reagent , phosphorous , filtrate , sewerage treatment facilities , biogenic elements , sludge water , intrasite sewage system
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UDC 628.35:661.63.001.42
KOZLOV M. N., Nikolaev Yu. A., KAZAKOVA E. A., Khramenkov S. V., Pakhomov A. V.
Industrial tests of biological and chemical phosphorus removal at the Moscow wastewater treatment facilities
Summary
The results of industrial-scale testing of combined biological and chemical phosphorus removal technology with the addition of ferric chloride at the Lyubersty wastewater treatment facilities are presented. The process of eliminating phosphorus from the municipal wastewater low in organics is unstable. During the experiment high level of phosphate removal (to 0.2 mg/l) was reached on retention of high efficiency removal of other pollutants. The use of ferric chloride does not influence the efficiency of biological nitrogen removal; however, the efficiency of phosphorus removal decreased a little. The recommendations were developed on using biological and chemical method of phosphorus removal as a temporary measure to provide for the required quality of effluent during high phosphorus load.
Keywords
wastewater , phosphorous , ferric chloride , biologic and chemical technology
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UDC 628.35
SHVETSOV V. N., MOROZOVA K. M., Stepanov S. V.
Designing facilities for municipal and industrial wastewater biological treatment in aeration tanks with nutrients removal
Summary
Biological treatment facilities are the basic facilities for the purification of domestic, municipal and industrial wastewater of most of the industries (chemical, petrochemical, oil refining, food, textile, consumer goods, coke-chemical industries, agriculture etc.). However until now there has been no scientifically-grounded method of designing wastewater biological treatment facilities with nitrogen and phosphorus removal in the Russian Federation. Many years of extensive research carried out by NII VODGEO and «Water Supply and Wastewater Disposal» chair of the Samara State Technical University at the laboratory and pilot plants, at the operating facilities with processing data bulks provided for developing an adequate method of designing aeration tanks with nutrients removal. The presented method is a supplement of the method of process design of biological treatment facilities stated in SNiP 2.04.03-85 with regard to designing aeration tanks with nitri-denitrification and biological phosphorus removal; and provides for the calculations of upgrade and new construction of the facilities for biological treatment of municipal, domestic and industrial wastewater. Behind the process design is the concept of the process description with enzyme kinetics equations. The method includes the following stages: substantiation of the relevant basic data on the flow rates and qualitative composition of wastewater; determination of the process flow scheme and burden balance calculation of all the critical pollution components; determination of the kinetic constants and coefficients of enzyme kinetics equations of the transformation of each basic pollution component (BOD, nitrogen compounds, phosphorus etc.) and activated sludge growth by the statistical analysis of the operation data and chemico-analytical analysis of wastewater samples of the operating treatment facilities, by experimental data or on the basis of the available analogies; calculation of the volume of all the elements of the facilities with determination of the limitative component and treatment level in relation to other pollutants; final correction of the volumes and parameters of all the process zones with account of the requirements to the level of treatment in relation to all the dictating pollution components. An example of the calculation is set. It is noted that the computation algorithm and formulas included into the method provide for designing any complicated process flow schemes with nitrogen and phosphorus removal applied both to municipal and industrial wastewater. The method provides for calculating not only the rate of removing BOD and nitrogen compounds but also other certain pollution components (oil products, detergents, fats etc.) offering additional opportunities of the wastewater biological treatment method. The method is especially useful in designing industrial wastewater biological treatment facilities because most of the foreign methods are mainly focused on the purification of domestic and municipal wastewater to the concentrations adopted in those countries. The method is developed on the principle of essential sufficiency; however is contains 70 design parameters and 28 formulas and equations. Accordingly the calculations are performed in Microsoft Office Excel which makes it possible for users even with middle software skills. Herewith it is possible to perform calculations straight for several options interactively and/or upgrade the treatment facilities in the process of their operation.
key words
biological treatment , nitrification , denitrification , nitrogen , phosphorous , activated sludge , kinetic constants , process design method , industrial and municipal wastewater
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