Improving the photobioreactor operation efficiency in the technological scheme of wastewater treatment

Conventional process schemes of municipal sewage water treatment, advantages, and disadvantages of the methods applied when removing biogenic elements were considered. It was shown that the existing shortcomings cause additional explicit costs and difficulties when disposing of the resulting waste. Low efficiency of the removal processes themselves causing residual concentrations of biogenic elements in the treated sewage water was also shown. A process scheme for treating municipal sewage water was proposed. It includes the use of a photobioreactor of a proposed design for the removal of biogenic elements due to the metabolism of microalgae. It was experimentally shown that the use of Euglena gracilis strain for removal of phosphates in initial concentrations of 4, 7, and 14 mg/dm3 from sewage water is the most efficient way. It makes it possible to reduce these concentrations to residual 0…0.55 mg/dm3 in four days. A 3.75…5.58 times increment of microalgae biomass during this period was also shown. A mathematical model was constructed for calculating the time of staying the sewage water and microalgae mixture in a photobioreactor to achieve the required degree of removal of biogenic elements. Based on the proposed model and experimental studies, the required time of staying in the rector working area was calculated. It was shown that with the use of Euglena gracilis strain but without removal of biogenic elements at previous purification stages (process schemes including only mechanical purification), the time of mixture staying in the working zone was 37.81 hrs. With partial removal of biogenic elements at the stage of biological treatment (0.55 mg/dm3 total nitrogen, 0.91 mg/dm3 ammonium nitrogen, 0.44 mg/dm3 phosphates), this time was reduced to 26.66 hrs. It was found that the use of Euglena gracilis strain instead of Chlorella vulgaris (FC-16) in the removal of phosphates results in a 2-time increase in the process efficiency and a 50 % decrease in time of mixture staying in the working zone. Recommendations for calculating geometric parameters of photobioreactors of the proposed design were given for use in the process schemes

ANALYSIS AND TREATMENT OF WASTE WATER FROM FISH PROCESSING ENTERPRISES

A distinctive feature of waste water of fi sh processing enterprises is the high content of organic substances: COD - 620-3500 mg/L, BOD-220-2860 mg/L. The ratio of BOD:COD=0.68-0.83 in the waste water of fi sh processing enterprises shows a high potential for the use of biological treatment methods. Further study requires the removal of biogenic elements, because, for example, for a fi sh cannery, the ratio of BOD:N:P=100:3.79:1.08 and 100:4.77:0.57. This article presents the experience of design, construction, start-up and adjustment of sewage treatment facilities of a fi sh processing enterprise. For wastewater treatment, the following scheme was developed and manufactured by the ECOLOS company: a receiving well with a basket, a drum grate, a horizontal grease trap, an homogenizer, a reagent pressure fl otation unit, a membrane bioreactor, and ultraviolet disinfection. The quality of waste water at the outlet of the treatment facilities meets the requirements of the Normative- permissible discharge provided by LLC «Russkaya Treska».

Peculiarities of biogenic elements migration in case of complex utilization of bioorganic component of municipal solid waste

Finding solutions to the problem of municipal solid waste management is impossible without involvement in the waste management system of the largest group of wastes – bioorganic waste, which form up to 60% of the municipal solid waste total mass. The aim of the article is to analyze the redistribution of biogenic elements subject to implementation of the Concept of solid municipal waste management by OSENU and subsequent utilization of bioorganic waste flow. Research methods include mass balance and equations of methane generation. The article presents the results of research on the biogenic elements migration in case of complex utilization of bioorganic component of municipal solid waste. The study shows that processing of easy-decomposed organic waste into a gaseous fermentation product and biomineral fertilizer allows full involvement of biogenic elements in natural cycles. The processed solid products present an additional source of organic matter and biogenic elements needed by soil. In the event of humus and nutrients shortage in soil the retrieved-from-waste fertilizer becomes an important secondary resource, containing up to 65% carbon and almost 100% nitrogen, phosphorus and potassium. The rest of carbon is released with biogas and is eventually involved in natural cycles. Burial of such waste results in localization of biogenic elements in a landfill's body and gradual release of carbon with the products of destruction (27% over 50 years). All this data indicate the need for efficient use of such waste resource potential which is possible in case of easy-decomposed organic waste separation at the beginning of the municipal solid waste life cycle. Combustion releases only carbon in the form of carbon dioxide, the rest remains in ash. However, complex utilization of easy-decomposed organic waste ensures complete return of biogenic elements to the environment. Reuse of secondary raw materials in the form of paper and textile waste minimizes involvement in economic turnover of carbon from natural sources.

Evaluation of the ecological and geochemical state of surface water in Donbas

The article covers evaluation of the ecological and geochemical state of surface water and bottom sediments in Donbas, as well as their pollution resulting from spatio-temporal changes of natural and anthropogenic factors. It was established that chemogenic pollution occurs due to penetration of polluting elements into surface water as a result of filtration leaks from sedimentation tanks and water discharges made by enterprises of coal, chemical, metallurgical, coke-chemical and petrochemical industries. Increased concentrations of biogenic elements (mineral forms of nitrogen and iron) were recorded in the water of the Siverskyi Donets and the Luhan Rivers. The most significant deterioration of groundwater quality because of high content of sulfates and chlorides is observed within the watersheds of the Luhan River's valley. Measurement results of the metals content indicated an increased content of copper and manganese. Some values even exceed the average annual concentrations specified by the existing normative values. In general, the results of the pollutants content analysis in the river basins under study did not reveal significant changes in the content of heavy metals during the period of military actions as compared to the results of government monitoring by 2014. The obtained experimental data indicate that vanadium, chromium and copper dominate in bottom sediments of all the studied objects. The greatest accumulation of heavy metals is observed in the Bakhmutka River and the Kryvyi Torets River. The research established that copper and plumbum in the bottom sediment samples taken from the Kryvyi Torets exceed the background values by 4-5 times. Zinc and vanadium exceed the background content values by 10 and 4 times, respectively. The same indicators are slightly lower in the Volyntsevske Reservoir and this fact is associated with more intense processes of water exchange and certain peculiarities of bottom sediments granulometric composition. Concentration of zinc is 3 times as much as the background level, vanadium and manganese – twice as much. Heavy metals in the bottom sediments of the studied water bodies are characterized by uneven distribution. Vanadium and copper dominate in the content of bottom sediments. Concentrations of zinc, vanadium and nickel at certain objects also exceed their regional background content values. Titanium was detected in minimum quantities.

The persistent place at Lubrza: a small paradise for hunter-gatherers? Multi-disciplinary studies of Late Palaeolithic environment and human activity in the Łagów lake district (western Poland)

This paper summarises the results of multidisciplinary research, including pollen, plant macroremains, diatoms, Cladocera, molluscs and geochemistry from a 14C dated core and geomorphological records, which reconstruct the palaeoenvironmental conditions faced by Late Palaeolithic hunter-gathers in western Poland. Particular attention was paid to evidence for both human activity and the degree to which Late Palaeolithic groups may have affected the local environment, as recorded by the biogenic sediments in lakes located close to their campsites. Vegetation first appears locally in the Oldest Dryas, and consisted of subarctic tundra vegetation. During the Bølling period the landscape was generally open, with dwarf shrubs and scattered patches of Juniperus and Hippophaë shrubs. Betula (tree birch) expanded locally in the area only in the later Allerød; during the second part of the Allerød period, Pinus and Populus joined birch as a sparse woodland developed. During the Younger Dryas, the landscape changed significantly in comparison to the preceding warm period, as result of cooling and drying of the climate. The presence of microscopic charcoal and charred herbaceous plant particles made it possible to detect human activity. These analyses allowed us to reconstruct fire events near the site during its occupation by Hamburg and Federmesser cultural groups. An increase in the proportion of biogenic elements such as Na, K and Mg in the sediments indicate soil erosion, reflecting the activity of Hamburg groups. A relative increase in the frequency of Cladocera which favour eutrophic and turbid water was recorded in the period linked to Federmesser group activities. The intense use of this area was also indicated during the Younger Dryas.

On the issue of the feasibility of using modern technologies for biological phosphorus removal in low-capacity wastewater treatment plants

The article discusses the basic principles of wastewater treatment from biogenic elements, provides the necessary conditions for the biological removal of phosphorus compounds. The technology of pre-fermentation of the sediment of primary sedimentation tanks, options for its design, the main parameters of the process are described. Specific aspects of the operation of low-capacity wastewater treatment facilities are indicated and the expediency of using the technology of biological phosphorus removal in them is considered.

Analysis of Мethodological Аpproaches for Developping Nutrient Standards in Surface Waters

Analysis of a large scale of monitoring data, basis for developping new approaches to environmental regulation and control strengthening subject to natural water bodies regional status have been performed. Existing rating system assessments (MAD, LOC) of biogenic elements in wastewater which desuetude doen not meet modern requirements of multifactorial situational analysis have been stated. Methodological aspects of eutrophication factors management and ways of their minimization have been considered.

Mathematical modeling of the pollutant distribution process in the Gelendzhik Bay

Currently, the pollution problem of coastal sea waters in the resort areas of the Black Sea is becoming increasingly urgent. Thousands of chemicals, industrial and household waste enter the water basins every year, which significantly worsens the state of marine waters. Storm drains are saturated with pollutants at precipitation, washing out various chemical compounds, garbage and transporting them to the sea. In addition, a separate problem is poorly self-cleaning of the Gelendzhik Bay. A complete water change occurs in the period from 1 to 6 days. This paper covers the development, research and numerical implementation of a mathematical model of the pollution transport, including petroleum products, in the Gelendzhik Bay taking into account a number of important hydrodynamic and hydrophysical factors, methods of its numerical implementation, which allow predictive modeling of the pollution spread in shallow water systems in a limited time. A hydrobiological model of a coastal system characterized by significant depth differences has been developed. A three-dimensional mathematical model is designed to research the transformation of the phosphorus, nitrogen and silicon forms in the plankton dynamics problem. It takes into account the convective and diffusive transports, absorption and release of nutrients by phytoplankton, salinity, temperature, oxygen regime, etc. Using a spatial-three-dimensional hydrodynamics model, taking into account the physical properties of water environment of the coastal system, calculation results are used as input data for the development of scenarios for the dynamics of transport processes and the transformation of pollution biogenic elements in the water.

Use of Chlorella sorokiniana (Chlorellaceae, Chlorellales) microalgae for purification of waste water from the brewing industry

The paper presents some environmental problems of the brewing industry. The literature data on the methods of water purification using microalgae have been studied. The composition of wastewater from the brewing industry is shown to consist of few biogenic elements, namely: nitrogen, phosphorus and potassium, which are necessary for microalgae biomass cultivation. Therefore, the wastewater from the brewing industry can be used as a basis for making a nutrient medium to cultivate microalgae. In the experimental part, the effect of various dilutions of a suspension of microalgae Chlorella sorokiniana (C) grown on a nutrient medium with untreated wastewater (UWW) from the brewing industry was studied. Various percentage ratios of wastewater to microalga suspension were studied, namely: UWW/C = 70:30, 50:50, and 30:70 for the ability to absorb nitrogen, organic and inorganic carbon from dry matter, and to change the pH value. The dependences of the growth rate of microalgae at various percentage additives of the wastewater from the brewing industry are presented. It was shown that at a UWW:C = 30:70, this dependence is characteristic of the standard growth curve of a microorganism culture. A lag phase, phases of exponential growth and withering away are observed. At a 70:30 ratio, the harmful effect of effluents on the growth of microalgae is obvious, on the 3rd day their death occurs, the green solution acquiring a brown color to confirm the death of microalgae cells. It has been shown that the optimal UWW:C ratio is 30:70, with no loss of biomass, it grows well using pollutants for its nutrition. The color of the solution after cultivation was bright green, which corresponded to the color of healthy cells. At UWW:C = 30:70, the wastewater is purified up to 70% and 90% for total nitrogen and organic carbon, respectively. The pH value changes from acidic to neutral. Keywords: Chlorella sorokiniana, wastewater treatment, brewing industry