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Vol. 20 (2017 year), No. 3, DOI: 10.21443/1560-9278-2017-20-3

Kurkotilo V. N., Vasilieva Zh. V.
Resource-saving recycling technology of lipid-containing waste of the fishing industry

Nowadays the resource component of fish waste is underutilized, while it has unique properties of fish raw material. The topical area of research is the search for new technologies for processing waste to produce fish oil as a valuable source of polyunsaturated fatty acids, fat-soluble vitamins and other biologically active substances. In the work the technology of enzymatic hydrolysis of fish wastes has been tested and compared with the traditional thermal technology of obtaining fat from fish waste. The object of the study has been frozen waste from the herring processing. The optimal parameters of obtaining fish oil from processing wastes has been determined by simulating the process by the method of mathematical planning of experiment using orthogonal central composite plan of the second order for two factors. The variation of the factors of traditional thermal processing has been carried out in the temperature range of 60 ± 10 °C for 120 ± 20 min. Enzymatic hydrolysis has been held using the enzyme preparation of proteolytic action Protosubtilin G3x (Protosubtilin G3x) in the range factors of 0.20 ± 0.05 g/kg dose of enzyme for 80 ± 20 min at the optimal temperature of hydrolysis. Organoleptic indicators of fat (appearance, color, smell, taste, transparency) have been determined in accordance with the requirements of state standards. The derived lipid drug has been subjected to research on indicators of safety in accordance with the requirements of Technical regulations of the Customs Union "On safety of food products". The safety performance of the obtained samples of fat (peroxide and acid numbers) has been determined by the standard methods. The constructed mathematical models contribute to optimizing the processing of fish waste. Comparison of the quality and safety indices of the obtained fish oil preparations has allowed substantiate the advantages of enzymatic processing of fish waste.

(in English, стр.9, fig. 2, tables. 6, ref 21, Adobe PDF, Adobe PDF 0 Kb)

Vol. 21 (2018 year), No. 1, DOI: 10.21443/1560-9278-2018-21-1

Vasilieva Zh. V., Moshnyatckaya E. Yu.
Extraction of bioflocculants from activated sludge and their application to wastewater treatment

Extracellular polymeric substances (EPS) – biopolymers produced by the microorganisms – are effective flocculants of wastewater pollution and lack the shortcomings of traditional coagulants and flocculants, which can pose direct threat to health and human life, as well as to the sustainable existence of aquatic and terrestrial ecosystems. EPS do not form secondary contamination of their degradation intermediates, are biodegradable and eco-friendly. Industrial production of bacterial EPS is associated with high cost of growing specific microbial biomass and the functioning of technologies for the synthesis of microbial products. At the same time, there is an underused resource of excess activated sludge, which can be used as cheap substrate for producing bioflocculants and a possible measure to reduce costs. The conducted researches have shown the prospects of extracting EPS from excess activated sludge for their subsequent use as wastewater treatment bioflocculants. EPS extraction has been conducted using three methods: combination of centrifugation processes, extraction using the aqueous solution of disodium ethylenediaminetetraacetic acid, and precipitation with isopropyl alcohol (the EDTA method); combination of centrifugation, extraction with (NH2)2CO, precipitation and ethanol reprecipitation (the (NH2)2CO method); combination of activated sludge ultrasonic treatment, centrifugation, extraction with glacial acetic acid, and precipitation with acetone (the CH3COOH method). The research has shown that the extraction method affects not only the efficiency of EPS extraction, but also the possibility of EPS application for the purification of certain types of sewage. The (NH2)2CO method has shown the best extraction efficiency, but at the same time EPSs produced have not be able to perform fish processing wastewater treatment. The EDTA and CH3COOH methods are more preferable for producing efficient bioflocculants for fish processing wastewater treatment. The use of EPS obtained by the EDTA method has resulted in the significant reduction of total suspended solids and optical density; EPS produced by the CH3COOH method have reduced the content of dissolved solids and the optical density. According to the conducted research EPS produced from surplus sludge with the EDTA and CH3COOH methods have good flocculation and are harmless for humans and the environment, and thus may be a potential substitute for traditional synthetic flocculants and could be used in the treatment of fish processing plants wastewaters.

(in English, стр.7, fig. 4, tables. 4, ref 16, adobe PDF, adobe PDF 0 Kb)

Vol. 22 (2019 year), No. 1, DOI: 10.21443/1560-9278-2019-22-1

Vasilieva Zh. V., Gorbovskaya T. D., Pavlov A. V.
Recultivation of oil contaminated soil using organic wastes in the Kola North conditions

Extraction, transportation, transshipment and storage of oil lead to accidental pollution of soil with oil products. To solve this problem, the possibility of using organic waste produced by the Murmansk region for the remediation of oil-polluted soils in the Kola North has been studied. The study has been carried out for three months at temperatures from 10 to 18 °C simulating the temperature conditions of the summer months on the Kola Peninsula. The contaminated soil was collected outside of Murmansk borders and the zones of industrial pollution on the Kola Peninsula. The soil type is podzol. Pollution modeling has been carried out by introducing F-5 fuel oil into the soil. The following organic components have been used as reclamation agents: excess activated sludge from biological treatment facilities of the enterprise Murmanskvodokanal; Saccharomyces cerevisiae brewery sedimentary beer yeast of the Murmansk region; chitosan – a product of conversion of Kamchatka crab processing waste. Reclaimers have been applied in concentrations of 16, 20 and 20 g/kg of soil respectively. The effectiveness of reclaiming of fuel oil contaminated soils has been assessed during measuring the oil content by the fluorimetric method and the ecotoxicological phytotesting of the studied soil samples. At the end of the reclaiming period, the greatest decrease in the concentration of oil products (up to 62 %) is observed in samples with active sludge. In soil samples reclaimed by sedimentary yeast and chitosan, the decrease in concentration is 48.7 and 54.6 % respectively; at the same time, the level of soil self-purification is 22.6 %. The results of the experiment allow us to make a reliable conclusion about the effectiveness and feasibility of using excess activated sludge, sedimentary yeast and chitosan as remediation of oil-polluted soils

(in Russian, стр.11, fig. 8, tables. 1, ref 22, Adobe PDF, Adobe PDF 0 Kb)