ОСВЕТЛЕНИЕ СТОЧНЫХ ВОД В ЛОКАЛЬНОМ ВОДООЧИСТНОМ ОБОРУДОВАНИИ СИСТЕМ ОБОРОТНОГО ВОДОСНАБЖЕНИЯ

Coagulants and flocculants are used almost at all drinking water supply facilities, wastewater treatment plants of municipal and industrial enterprises in Belarus and Ukraine to intensify and increase the efficiency of the processes of purification, clarification and discoloration of water and wastewater. Mainly as coagulants aluminum and iron salts are used, as flocculants - active silicic acid, starch, cellulose derivatives, polyacryloamide, etc. 
 Sulfuric acid treatment of alumina-containing raw materials allows, in the course of one process, to obtain a mixture of active substances - salts of aluminum, iron, active SiO2. In this case, there is no need to separate the salt from suspended particles and colloidal silicic acid. The presence of suspended dispersed particles in the active substance, as well as colloidal silicic acid and its salts, enhances and accelerates coagulation. The resulting solution, along with aluminum sulfate, contains silicic acid, which acts as a flocculant in the process of water purification. In addition, the processed products also contain ferrous sulfate, in the presence of which a better coagulation result is achieved. 
 Industrial tests of the coagulant-flocculant were carried out in order to purify wastewater from oil products. The test results showed that the effectiveness of the coagulant-flocculant in reducing the content of oil products in wastewater is comparable to the currently used aluminum sulfate.
 The effectiveness of the developed coagulant-flocculant for the purification of drinking water was evaluated in comparative tests with a coagulant “Polvak-68” in the mode of trial coagulation on a laboratory flocculator. The research results are showed that the value of all parameters characterizing the contamination of the source water are highty decreasing for experimental coagulant-flocculant in compare with regular product.

Waste water treatment plants are complex systems consisting of construction, hydro-mechanical, electrical, monitoring and automation equipment. Monitoring activities emphasize that the processes are dynamic; wastewater quality at the entering point of treatment plant varies in a wide range. Treatment technologies adopted must reduce major pollutants; that involves nitrification-denitrification processes and biological and chemical reduction of phosphorus through mechanical-chemical-biological treatment pathways. Increasing the activated sludge concentration in a wastewater treatment plant is an effective method by altering the process dynamics and by reducing the produced sludge volume. There are proposed and discussed in terms of technical and cost efficiency different technological wastewater treatment schemes. In Romania, wastewater treatment plants and sewage systems operating involve processes based on the new systems overrated, there is mandatory to diminish quantities in water supply systems and to exclude improperly working of wastewater pre-treatment stations. Those operations impose technological measures ensuring efficient functioning regardless the service conditions.

The formation of trihalomethanes (THMs) in natural and treated water from water supply systems is an urgent research area due to the carcinogenic risk they pose. Seasonal effects and pH have captured interest as potential factors affecting THM formation in the water supply and distribution systems. We investigated THM occurrence in the water supply chain, including raw and treated water from water treatment plants (coagulation, sedimentation, sand filtration, ClO2-disinfection processes, and distribution pipelines) in the Chiang Mai municipality, particularly the educational institute area. The effects of two seasons, rainy (September–November 2019) and dry (December 2019–February 2020), acted as surrogates for the water quality profile and THM occurrence. The results showed that humic acid was the main aromatic and organic compound in all the water samples. In the raw water sample, we found a correlation between surrogate organic compounds, including SUVA and dissolved organic carbon (DOC) (R2 = 0.9878). Four species of THMs were detected, including chloroform, bromodichloromethane, dibromochloromethane, and bromoform. Chloroform was the dominant species among the THMs. The highest concentration of total THMs was 189.52 μg/L. The concentration of THMs tended to increase after chlorination when chlorine dioxide and organic compounds reacted in water. The effect of pH on the formation of TTHMs was also indicated during the study. TTHM concentrations trended lower with a pH ≤ 7 than with a pH ≥ 8 during the sampling periods. Finally, in terms of health concerns, the concentration of TTHMs was considered safe for consumption because it was below the standard (<1.0) of WHO’s Guideline Values (GVs).

Abstract. The urgency of the problem of local biological treatment of domestic wastewater from housing in non-canalized areas with improving the quality of treated wastewater to the level of requirements for discharge into fishery bodies of water is considered. The analysis of the state of local wastewater treatment is given. Existing technological schemes and methods of local sewage, which are used for sewage treatment, are considered. The results of theoretical and experimental studies of a complex of a local anaerobic-aerobic biological treatment of domestic wastewater from housing in non-canalized areas at the low-productivity plants are presented. The results of theoretical and experimental researches of complex of local anaerobic-aerobic biological purification of domestic wastewater of habitation in non-canalized areas at the low-productivity plants are given. On the basis of the analysis of work and embodiment of low-productivity plants, used in home and foreign practice of local treatment of domestic wastewater the expediency of application flowing multistage anaerobic-aerobic biological purification of domestic wastewater with use of communities of attached and free-swimming microorganisms is shown. The proposed low-productivity plant, which includes a three-stage aerobic biological treatment of anaerobically treated wastewater is described. The use of ruff fillers for the retention of hydrobionts gives the opportunity to clear salvo discharge, rapid restoration of the activity of the ruff fillers (for example, in power outages). The ruff fillers make it possible to organize an appropriate trophic chain of hydrobionts, which dramatically reduces the amount of excess biomass and the removal of suspensions in treated wastewater. Using the experiments in laboratory conditions and at real industrial treatment plant of a new design there were received parameters of work of stages of anaerobic and aerobic biological purification, the law of nitrification and denitrification processes, the law of specific speed of oxidation of organic pollution in specific conditions of anaerobic-aerobic technology; the opportunity of reception of quality of treated wastewater at the level of the requirements of the specifications for dump of drains in fishing reservoirs is proved.

Textile industry processes are among the most environmentally unfriendly industrial process, because they produce colored wastewaters that are heavily polluted the environment. Therefore, wastewater from textile industry has to be treated before being discharged into the environment. In this present study, an attempt has been made to evaluate the effectiveness of locally available natural coagulant Neem leaves powder for reduction of characteristics in the wastewater in order to improve its quality. A common herb like Neem leaves powder is utilized to illuminate and sterilize the water. The coagulant chemicals play the vital role in wastewater treatment. At the same time spending more amounts for these chemical coagulants increase the total treatment cost and become more burdens to the industry. In view of the replacement or reduction of chemical coagulants which are used in wastewater clarification, coagulants which are effective, productive and also free from physio-chemical characteristics are considered. Using natural coagulants is more eco-friendly and sustainable when compared to the chemical coagulants which is biodegradable.

Legionella spp. is one of the most important water-borne pathogens that can cause both outbreaks and sporadic cases. Legionella is spread by water aerosols containing the bacteria. In the form of aerosols, bacteria can spread several kilometres from the primary source of infection while remaining viable. Legionellosis is a preventable disease and a form of atypical pneumonia caused by Legionella pneumophila and related bacteria. Clinical manifestations of the disease range from a mild, self-limiting flu-like illness (Pontiac fever) to potentially fatal pneumonia (Legionnaires' disease). The aim of the study was to investigate Legionella spp. distribution trends, genetic diversity and virulence potential for diagnosis and prevention of legionellosis in Latvia. Materials and methods. To assess the seroprevalence of L. pneumophila in the general healthy population and to identify associated risk factors, 2007 blood samples were collected from healthy blood donors. To evaluate Legionella spp. distribution in water supply systems, 1467water samples were taken in different types of buildings. 137 L. pneumophila isolates were selected for the study of genetic diversity and virulence genes were determined for 58 isolates. Immunoenzymatic reaction was performed for all blood samples to detect IgG antibodies against L. pneumophila SG 1-6. Determination of Legionella spp. in water and biofilm samples was performed according to a standardized method. Free-living protozoa were determined morphologically and by three different PCR protocols. Whole genome sequencing of L. pneumophila isolates was performed with Illumina MiSeq. Sequence-based typing was performed according to the scheme developed by ESCMID. cgMLST typing was performed using the previously described protocol. The database of virulence factors was used to determine virulence determinants. Results. The seroprevalence of L. pneumophila SG 1-6 in blood donors was 4.8 % and 0.2 % of donors were seropositive for L. pneumophila SG1. Seroprevalence was higher in women (5.9 %) than men (3.3 %), and in regions with a larger population, ranging from 3.5 % in rural regions to 6.8 % in the capital Riga. Legionella spp. prevalence in water supply systems varied from an average of 25 % in cold water samples to 35 % in hot water samples. The predominant L. pneumophila serogroup (SG) was SG 3, which was identified in 208 of 482 cases (43.2 %). At least one free-living amoeba genus was detected in at least 77.2 % of the samples. The average hot water temperature was 47.8 ± 0.7 °C. Temperature measurements showed that only 249 out of 1275 hot water samples exceeded 55 °C. Overall, 137 L. pneumophila strains included in the study represented 46 sequence types, including new 10 sequence types, previously unrecorded in the world. Using cgMLST typing 116 genotypes were obtained. 420 virulence genes were identified of which 260 genes were found in all sequenced L. pneumophila isolates. Virulence factors encoding enhC, htpB, omp28 and mip genes were detected in all isolates, suggesting that adhesion, attachment and entry into the host cell are enabled for all isolates. Relative frequency of virulence genes among L. pneumophila isolates was high. Conclusions. Residents of apartment buildings are exposed to a higher risk of legionellosis than those living in private houses (OR = 2.23; p = 0.011). The highest risk of seropositivity was for residents of buildings with centralized hot water supply (OR = 3.16; p = 0.001). High Legionella spp. prevalence in water supply systems is related to low hot water temperature (average 47.8 ± 0.7 °C) and high presence of free-living amoebae (84.2 %). Environmental isolates of L. pneumophila exhibited a high diversity of SBT and cgMLST sequence types and showed signs of regional clonal expansion, with ST-338, ST-366 and ST-1104 as the predominant sequence type group characteristic of our region. The relative frequency of virulence genes suggests that L. pneumophila isolates have a high virulence potential and the presence of a wide range of virulence factors. 3.1 Basic medicine; Sub-Sector – Other Basic Medicines. Keywords: Legionella, genetic diversity, cgMLST typing, virulence.

Energy and water autarky of wastewater treatment and power generation systems

Phylogenetic analysis of environmental Legionella pneumophila isolates from an endemic area (Alcoy, Spain)

The object of the study is the water supply and sanitation system of an industrial enterprise. Currently, many enterprises do not use the treated industrial waste water in the water supply cycle. Therefore, the use of treated wastewater is of practical importance. The scheme of thermal treatment of waste water for obtaining pure condensate by evaporation is proposed. The main results of the study are the technical solution for the development of the enterprise's wastewater treatment complex. Pure condensate is obtained in an instant boiling evaporator. The research method is based on the calculation of energy costs in wastewater treatment for different types of waste water. The results of the study allow us to determine the optimal set of energy equipment for obtaining pure condensate and its further use. The specific practical significance lies in the development of a technical solution that helps the treatment of wastewater and the reduction of emissions into the water basin.

At the modern stage of construction branch development there is a current task of forming the indicator, the application of which will allow forecasting the final indicator of a construction project depending on organizational-technological and management solutions influencing it - the organizational and technological capacity of a construction project. The construction project capacity, which has been actively investigated in the recent years, is formed on the basis of account for the processes directly or tangentially related to production and technological specifics of the construction industry on all the stages of project development: design solutions, preparation of a construction site, general construction and finishing works, special works (building water supply and water disposal systems, technological equipment, electric wiring and low currents, ventilation, conditioning and fire security, elevators), external supply lines, amenities. The introduction of organizational-technological capacity concept of a building project in the form of a numerical integral value is given in the article, allowing to make relevant management decisions at any step of the construction project. The article deals with the essence of information flows as an important component in the construction project evaluation. The authors discuss the separation of information flows into groups, depending on different criteria. As a result, the mathematical model is offered, which gives the construction project potential evaluation with taking into account the impact of information flows.

Pharmaceuticals are useful tools to prevent and treat human and animal diseases. Following administration, a significant fraction of pharmaceuticals is excreted unaltered into faeces and urine and may enter the aquatic ecosystem and agricultural soil through irrigation with recycled water, constituting a significant source of emerging contaminants into the environment. Understanding major factors influencing their environmental fate is consequently needed to value the risk, reduce contamination, and set up bioremediation technologies. The antiviral drug Tamiflu (oseltamivir carboxylate, OC) has received recent attention due to the potential use as a first line defence against H5N1 and H1N1 influenza viruses. Research has shown that OC is not removed during conventional wastewater treatments, thus having the potential to enter surface water bodies. A series of laboratory experiments investigated the fate and the removal of OC in surface water systems in Italy and Japan and in a municipal wastewater treatment plant. A preliminary laboratory study investigated the persistence of the active antiviral drug in water samples from an irrigation canal in northern Italy (Canale Emiliano Romagnolo). After an initial rapid decrease, OC concentration slowly decreased during the remaining incubation period. Approximately 65% of the initial OC amount remained in water at the end of the 36-day incubation period. A negligible amount of OC was lost both from sterilized water and from sterilized water/sediment samples, suggesting a significant role of microbial degradation. Stimulating microbial processes by the addition of sediments resulted in reduced OC persistence. Presence of OC (1.5 μg mL-1) did not significantly affect the metabolic potential of the water microbial population, that was estimated by glyphosate and metolachlor mineralization. In contrast, OC caused an initial transient decrease in the size of the indigenous microbial population of water samples. A second laboratory study focused on basic processes governing the environmental fate of OC in surface water from two contrasting aquatic ecosystems of northern Italy, the River Po and the Venice Lagoon. Results of this study confirmed the potential of OC to persist in surface water. However, the addition of 5% of sediments resulted in rapid OC degradation. The estimated half-life of OC in water/sediment of the River Po was 15 days. After three weeks of incubation at 20 °C, more than 8% of 14C-OC evolved as 14CO2 from water/sediment samples of the River Po and Venice Lagoon. OC was moderately retained onto coarse sediments from the two sites. In water/sediment samples of the River Po and Venice Lagoon treated with 14C-OC, more than 30% of the 14C-residues remained water-extractable after three weeks of incubation. The low affinity of OC to sediments suggests that the presence of sediments would not reduce its bioavailability to microbial degradation. Another series of laboratory experiments investigated the fate and the removal of OC in two surface water ecosystems of Japan and in the municipal wastewater treatment plant of the city of Bologna, in Northern Italy. The persistence of OC in surface water ranged from non-detectable degradation to a half-life of 53 days. After 40 days, less than 3% of radiolabeled OC evolved as 14CO2. The presence of sediments (5%) led to a significant increase of OC degradation and of mineralization rates. A more intense mineralization was observed in samples of the wastewater treatment plant when applying a long incubation period (40 days). More precisely, 76% and 37% of the initial radioactivity applied as 14C-OC was recovered as 14CO2 from samples of the biological tank and effluent water, respectively. Two bacterial strains growing on OC as sole carbon source were isolated and used for its removal from synthetic medium and environmental samples, including surface water and wastewater. Inoculation of water and wastewater samples with the two OC-degrading strains showed that mineralization of OC was significantly higher in both inoculated water and wastewater, than in uninoculated controls. Denaturing gradient gel electrophoresis and quantitative PCR analysis showed that OC would not affect the microbial population of surface water and wastewater. The capacity of the ligninolytic fungus Phanerochaete chrysosporium to degrade a wide variety of environmentally persistent xenobiotics has been largely reported in literature. In a series of laboratory experiments, the efficiency of a formulation using P. chrysosporium was evaluated for the removal of selected pharmaceuticals from wastewater samples. Addition of the fungus to samples of the wastewater treatment plant of Bologna significantly increased (P < 0.05) the removal of OC and three antibiotics, erythromycin, sulfamethoxazole, and ciprofloxacin. Similar effects were also observed in effluent water. OC was the most persistent of the four pharmaceuticals. After 30 days of incubation, approximately two times more OC was removed in bioremediated samples than in controls. The highest removal efficiency of the formulation was observed with the antibiotic ciprofloxacin. The studies included environmental aspects of soil contamination with two emerging veterinary contaminants, such as doramectin and oxibendazole, wich are common parasitic treatments in cattle farms.

The paper investigates the use of CAD-CAM technologies for the design and manufacture of parts on machines with numerical program control (CNC). These technologies allow designing technological routes of processing of surfaces of details of various complexity and making them on modern processing centers with CNC, and their use in the conditions of small-scale, single productions is justified and economically rational.Many operating enterprises in various industries have long been using technological equipment that is morally and physically obsolete. As a rule, wear parts (spare parts) are no longer produced for them. Replacement of obsolete technological equipment in the existing technological schemes of the production process of the enterprise requires significant material and financial costs, and its repair is complicated by the lack of spare parts. Therefore the question of manufacturing by the individual order of the enterprise of a small amount of worn out details for increase of maintainability of the operating technological equipment is actual.The article is devoted to the study of the possibilities of using CAD-CAM software systems «Autodesk Inventor», «ESPRIT» and «Creo Parametric» for the manufacture of custom worn impeller centrifugal electric pump KM 65-50-220, installed in the water treatment system of the food process .The step-by-step sequence of designing and manufacturing of a new improved (modernized) part instead of worn-out, possibilities and advantages of modern CAD-CAM software complexes, technological possibilities of CNC equipment is investigated. It is shown that the use of CAD-CAM systems «Autodesk Inventor», «Esprit» and «Creo Parametric» and a modern machining center Haas UMC-750 with CNC for the manufacture of a new improved design of the impeller of the electric pump, in single production, has significantly reduced technological time, preparation for the manufacture and replacement of worn parts, to improve the quality, reliability, durability and maintainability of the equipment operating at the enterprise.

Water resources of Russia are a national wealth and not only the level of economic development of the country, but also health of the population depends on their state. Rational use of water resources at the industrial enterprises is provided with the independent, closed water supply systems equipped with devices of vaporizing cooling of water. The systems of reverse water supply are one of the most important elements of a technological complex of the enterprises of many industries: chemical, oil processing, petrochemical, machine-building, metallurgical, etc. Capacity of processing equipment, quality and cost of the product, a specific consumption of raw materials and the electric power depend on quality and overall performance of systems of reverse water supply. One of elements of a system of reverse water supply is the cooler. In this article the design of the water catcher of the cooler Application of the Offered Design is described will allow to reduce considerably moisture content in the steam-gas stream released by the cooler into the atmosphere.

BACKGROUND: During the operation of transport and technological machines and equipment, the most frequent failure is loose running of connecting rod liners of a crankshaft. Previous studies on tractor, locomotive and automotive diesel engines did not sufficiently disclose the reasons for loose running of liners. AIMS: Study of the stress-strain state of the steel base of connecting rod liners as the initial and developing factors of the process leading to failure. METHODS: The research is based on the analysis of numerous works devoted to the study of the causes of loose running of connecting rod liners of various internal combustion engines. The methods and results on the operational and bench studies of the stress state and shape changing of connecting rod liners for the KAMAZ-740 (8Ch 12/12) engine obtained by the team of authors are used as the basic data. RESULTS: The process of change in stress state and consequent change in geometric parameters of the steel base, accompanied by change in the shape of connecting rod liners of the KAMAZ-740 engines has been revealed. It is established with the study that the occurrence of failure is not sudden. The process proceeds according to a certain pattern in three stages. The first stage is characterized by the appearance of deformation of a liner due to excessive stress state; the second stage is caused by development of obtained deformations up to critical values; the third stage is loose running of a connecting rod due to obtained deformations and violations of liner’s hydrodynamics conditions. The main result is justification of requirements and conditions for ensuring stability of parameters and shape of liners during long-term operation of engine. CONCLUSIONS: Knowledge of the process leading to the change in shape of crankshaft bearing liners makes it possible to develop design and technological solutions and recommendations to eliminate failures by optimizing the parameters of liners.

The present work provides an experimental assessment and proves the possibility of reducing wastewater flow rates in water treatment systems, as well as storm and household sewage, to volumes allowing their inland transportation, which would help avoid environmental pollution and costs associat-ed with building drainage networks. The paper describes major environmental problems that often arise while establishing water supply and drainage systems at new facilities under construction, remote from drainage networks. New reverse osmosis and nanofiltration membrane technologies are consid-ered that ensure high-quality purification of both drinkable and process water and wastewater treat-ment, allowing the latter to be reused for technical purposes. The main advantage of new technologies comprises a significant reduction in water consumption for the balance-of-plant needs, which allows discharges to sewers to be avoided. The study provides process diagrams and experiments demon-strating the possibilities of reducing the volume of concentrates. Technologies for residential building sites are proposed, offering a possibility of designing autonomous systems of water supply and dis-charge (runoffs and sediments) by vehicles. Furthermore, the volume of wastewater is less than 0.5% of that of water consumed for drinking needs. The described approach to designing water supply and wastewater treatment systems can be used for developing waterworks systems at facilities remote from water supply and sewerage networks, as well as reservoirs where treated wastewater can be dis-charged. Wastewater purified by reverse osmosis can be used for feeding the recycling water supply network (equipment cooling) and green spaces irrigation.