«Organic belt around Kazakhstan cities – 2020» environmental project

Summary

The description of «Organic belt around Kazakhstan cities – 2020» environmental project that engages essentially the water industry and that is being implemented nowadays is presented. The timeliness of the project comes from the amendment of the national legislation, Article 301 of the Environmental Code of the Republic of Kazakhstan in particular (2016), that is related to the regulation of waste landfilling. The new regulatory document limits (and actually prohibits) storing dewatered wastewater sludge on landfills and prescribes to provide for its further processing with the purpose of transferring theses wastes from «hazardous organic wastes» category to recultivants, cultivation soil etc. The project envisages the use of Russian technology of wastewater sludge dewatering on sludge beds with the use of «Sibflok®» flocculant and the technology of enhanced composting of organic wastes developed by the experts of International Academy of Ecology (Astana). The implementation of this project will provide not only for reducing significantly the amount of municipal sludge transported to landfilling but also for establishing the production of soil-like substrates, soils for remediation of desertificated territories, landfills, dumps; and in case of advanced processing – for urban greening services.

Key words

composting , dehydration , flocculant , sludge beds , environmental damage , wastewater sludges , reclamation , bio-conversion , remediation of disturbed lands

Economic Efficiency of the Use of Coagulant at the Pumping-Filter Station of the City of Samara

Summary

Results of the research in using the coagulant of aluminium polyoxychloride at the pumping-filter station № 1 of the city of Samara are presented. The technical and economic performance of the pumping-filter station № 1 are enhanced, working conditions are improved, amortization, energetic and other costs are reduced due to of simplification of chemical dosing workshop, release of equipment and mechanisms. In 2010 the general costs for chemicals were cut down by 16%. The combined scheme of water treatment with the use of aluminum sulfate and aluminum polyoxychloride enhances the stability of the treatment process of low-turbid water of the Saratov Reservoir.

Key words

coagulant , flocculant , pumping-filtration station , economic efficiency

The efficiency of removing suspended solids from biologically treated effluent by microscreening in disc filters

Summary

The article covers the results of studying the separation of suspended solids from biologically treated effluent and separation of mixed liquor from aeration tanks by microscreening method. The specialists of R&D Centre of «Mosvodokanal» JSC performed pilot testing of microscreening technology. The tests were carried out in a pilot plant designed on the basis of DynaDisc filter (Nordic Water Products AB, Sweden). The surface of filtration area was 2.8 m2. The tests were carried out at the Kur’ianovskie Wastewater Treatment Facilities in Moscow. In the course of studies it was shown that disc microscreening provided for effluent polishing with reducing suspended solids to 4 mg/l when using 18 µm sieve mesh and to 3 mg/l when using 10 µm sieve mesh. The concentration of suspended solids in backwash water is 0.5–1.4 g/l; backwash water flow rate does not exceed 1.2% of the installation capacity. Addition of Praestol 650 flocculant allows improving filtrate quality to 1 and 0.5 mg/l, respectively. The quality of filtrate during separation of mixed liquor from aeration tanks in DynaDisc filter with 50, 30 and 18 µm sieve mesh is, respectively, 140, 60 and 45 mg/l; suspended solids in backwash water – 30–70 g/l, backwash water flow rate – 6–8%. In the course of tests the optimal filter operational performance in effluent polishing and separating mixed liquor from aeration tanks by microscreening was determined.

Key words

wastewater treatment , flocculant , dragged particles , mixed liquor separation , microscreening , disc filter