bbk 000000
UDC 628.34:66.081
Maiboroda A. B., Katraeva I. V., Kolpakov M. V.
Effluent polishing with the use of ultrafiltration
Summary
The results of investigating the removal of phosphate ions and suspended solids that enhance eutrophication of water bodies from biologically treated domestic wastewater after secondary settling tank are presented. Experimental studies of effluent polishing with the use of ultrafiltration technology in combination with coagulation were carried in the laboratory of the Nizhny Novgorod State University of Architecture and Civil Engineering. The aluminium hydroxychloride dosage of 20 mg/l as Al2O3 was used as a coagulant. Hollow-fiber module manufactured by Fazerkraft Russian Company with polyvinylidenefluoride was used for tangential ultrafiltration in cycle mode. The membrane module is a device with a cylindrical shell with a bunch of hollow fibers inside with porous walls. The impact of transmembrane pressure on the filtration process was investigated. It was found that the specific flow rate of permeate increases with the increase of transmembrane pressure within the range of 0.05–0.2 bar. The tests showed that 20-fold increasing the concentration of the suspension subject to treatment does not result in any significant decrease of permeate production of the membrane module. Increasing recycling rate (of tangential flow) results in the increase of permeate flow; however, on account of technical and economic aspects, the range of low recycle flow values is of most interest. The results of the studies showed that the suggested ultrafiltration technology provided for almost complete elimination of suspended solids (more than 93% treatment efficiency), 97% reduction of phosphates in wastewater, and reduction to 0.04 mg/l aluminium concentration in permeate.
Key words
suspended substances , membrane module , wastewater aftertreatment , phosphates , ultrafiltration
|
bbk 000000
UDC 628.16.081:661(24+48+63)
Gandurina L. V., Potapova L. V.
Precipitating capacity of AQUA-AURAT™30 coagulant in water treatment in the presence of calcium hydroxide
Summary
The results of experimental studies of simultaneous elimination of sulphates, phosphates and fluorides from water with AQUA-AURAT™30 aluminium polyoxychloride in the presence of calcium hydroxide are presented. It was shown that the standard concentration of sulphates and phosphates is ensured with the chemical dosage ratio 4.5 (as active СаО/Аl2О3) and рН 11. Fluoride concentration under the circumstances is decreasing from 11 to 2 mg/l. The standard fluoride concentration in treated water is ensured at рН 7.
Key words
coagulant , water treatment , phosphates , aluminium polyoxychloride , calcium hydroxide , sulphates , fluorides
|
UDC 502.51(282)
DOI 10.35776/VST.2023.07.01
Chesnokova S. M., Savel'ev O. V.
Estimation of the anthropogenic load on small rivers by the level of pollution of bottom sediments with organic matter, phosphates and iron
Summary
The results of studies on estimating the anthropogenic load on small rivers of the Vladimir region in terms of the level of pollution of bottom sediments with organic matter, phosphates and iron (III) compounds are presented. The Ilevna, Kamenka and Sodyshka rivers are characterized by different surface areas and population level of their watersheds, and by the identity of non-point sources of pollution. It has been established that water and bottom sediments of the studied watercourses are heavily polluted with organic matter, phosphates and iron (III) compounds; and, consequently they are eutrophicated. In terms of the pollution of hydroecosystems with organic matter and phosphates, the watercourses form a series: Sodyshka > Kamenka > Ilevna, and in terms of the concentration of iron (III): Kamenka > Sodyshka > Ilevna. Judging from the COD index that characterizes pollution with organic compounds, the water of the Ilevna river is dirty, and the Sodyshka and Kamenka rivers are very dirty. The ecosystems of the Sodyshka and Kamenka rivers are heavily polluted. In order to prevent hypereutrophication and degradation, cleaning their riverbeds to remove bottom sediments is proposed. A method is suggested for calculating the anthropogenic load of certain pollutants with account of their concentration in the bottom sediments and watershed area.
Key words
phosphates , anthropogenous impact , bottom deposits , small rivers , organic matter , iron (III)
|
DOI 10.35776/VST.2022.04.03
UDC 502.51(282):504.5
Trifonova Tat’iana, Chesnokova S. M., Savel'ev O. V.
Estimating the effect of synthetic surfactants on the ecosystem
of a small watercourse
Summary
The results of studying the impact of anionic surfactants on the physicochemical and biochemical processes in the ecosystem of a small eutrophic watercourse by laboratory modeling are presented. It has been established that anionic surfactants inhibit nitrification processes in proportion to their concentration in water; migration of phosphates from bottom deposits occurs intensively in the concentration range of 0.02–0.1 mg/dm3, which is equivalent of the level of the studied watercourse pollution. At the concentration of anionic surfactants from 1.2 to 4 mg/dm3 in the model solution, the migration of phosphate ions from the bottom deposits deceased. Correlation analysis was used to study the effect of the composition of water and bottom deposits on the mobility degree of phosphate ions in the watercourse ecosystem.
Key words
phosphates , laboratory modeling , minor stream , anionic surfactants , mobility degree , correlation
|
bbk 000000
UDC 628.345.1
Zalyotova N. A.
Phosphorus compounds in municipal wastewater
Summary
The analysis of the results of determining phosphorus compounds in wastewater at the treatment facilities is presented. In order to remove phosphorus compounds different methods of municipal wastewater treatment are used. The efficiency of eliminating some or other phosphorus forms depends on the technology used. The ratio of separate phosphorus forms in raw sewage differ much from effluent; therefore their impact on the water body also differs even if the discharged effluent quality is meeting the maximum permissible concentration of phosphates. Addition of chemical into wastewater provides for the fast and reliable removal of phosphates. The efficient reduction of total phosphorus and phosphates occurs only under the combination of biological and chemical wastewater treatment, or under the use of the modified biological treatment with alternating aerobic and anaerobic conditions of activated sludge retention.
Key words
wastewater , biological treatment , chemical treatment , phosphates , total phosphorus , biological and chemical treatment
|
bbk 000000
UDC 628.35 (211)
Kounakhovich A. A.
Domestic wastewater advanced treatment unit for the use in the settlements of the northern climatic region
Summary
The experts from «Engineering Equipment Trading House» developed and mastered manufacturing of the treatment facilities for domestic wastewater and industrial wastes close by composition to domestic wastewater for the camps in the northern construction climatic region. Tver-C units for advanced treatment of domestic wastewater provide for the comprehensive solution to ensure efficient operation of the treatment facilities in rigorous climate northern areas.
Key words
disinfection , suspended substances , aeration , nitrification , wastewater treatment , phosphates , nitrites , nitrates , chlorides , microflora , denitrifier
|
|
