scholarly journals The applied mechanical equipments for wastewater treatment in the észak-Alföld region

2017 ◽  
pp. 171-178
Author(s):  
István Szőllősi ◽  
Tamás Antal ◽  
Zsuzsanna Uri ◽  
László Simon ◽  
Attila Szilágyi

In this study we presented the results of a survey research, which was performed during 2015 at 34 sewage treatment works, operating in Észak-alföld region (Hungary). The survey focused on applied mechanical equipment and works of art of the sewage treatment establishments. The results of the survey showed that the majority of the examined sites (approx 65%) are working with capacity utilization of 50–100%,merely the 12% of plants was overload. It was found analyzing of specific energy consumption of the sites that the largest value (1.1 kWh per m3) was at the plants with smaller capacity (0–1000 m3 per day). It was clear during the questionnaire processing of the survey that almost all of the works applied activated sludge for sewage treatment The sludge treatment of the sewage plants is conducted by two methods; aerobic- and mixed (anaerobic and aerobic) sludge stabilization. We suggest for the plants with small capacity to use deep aerators, since anachronistic method used the at 3% of the settlements.

2004 ◽  
Vol 50 (8) ◽  
pp. 125-133 ◽  
Author(s):  
M.-S. Park ◽  
Y. Kiso ◽  
Y.-J. Jung ◽  
M. Simase ◽  
W.H. Wang ◽  
...  

Small-scale wastewater treatment facilities play an important role in improving the aquatic environment in many countries. Although sludge treatment is essential for overall wastewater treatment, it is difficult for small-scale facilities to use mechanical equipment or other facilities. As the first step of the sludge treatment, it is important to develop a convenient sludge thickening process for small-scale facilities. In this work, we examined the sludge thickening performance of a mesh filtration system: the mesh opening sizes of 100-500 μm, and the sludge (3,000-9,000 mg-SS/L) was obtained from a domestic wastewater treatment facility. The filtration was carried out only under the hydraulic pressure between the water level and the effluent port connected to the mesh filter module. The sludge reduction rates were in the range of 85-95% for 6-7 h; the initial filtration rate was very high, but the rate decreased with a decrease in hydraulic pressure due to the reduction of the water level in the vessel. In addition, the effluents (passed through the mesh) contained very low SS and could be directly discharged into the environment.


2003 ◽  
Vol 47 (12) ◽  
pp. 43-48 ◽  
Author(s):  
J. Keller ◽  
K. Hartley

Many practical design and operating decisions on wastewater treatment plants can have significant impacts on the overall environmental performance, in particular the greenhouse gas (GHG) emissions. The main factor in this regard is the use of aerobic or anaerobic treatment technology. This paper compares the GHG production of a number of case studies with aerobic or anaerobic main and sludge treatment of domestic wastewater and also looks at the energy balances and economics. This comparison demonstrates that major advantages can be gained by using primarily anaerobic processes as it is possible to largely eliminate any net energy input to the process, and therefore the production of GHG from fossil fuels. This is achieved by converting the energy of the incoming wastewater pollutants to methane which is then used to generate electricity. This is sufficient to power the aerobic processes as well as the mixing etc. of the anaerobic stages. In terms of GHG production, the total output (in CO2 equivalents) can be reduced from 2.4 kg CO2/kg CODremoved for fully aerobic treatment to 1.0 kg CO2/kg CODremoved for primarily anaerobic processes. All of the CO2 produced in the anaerobic processes comes from the wastewater pollutants and is therefore greenhouse gas neutral, whereas up to 1.4 kg CO2/kg CODremoved originates from power generation for the fully aerobic process. This means that considerably more CO2 is produced in power generation than in the actual treatment process, and all of this is typically from fossil fuels, whereas the energy from the wastewater pollutants comes primarily from renewable energy sources, namely agricultural products. Even a change from anaerobic to aerobic sludge treatment processes (for the same aerobic main process) has a massive impact on the CO2 production from fossil fuels. An additional 0.8 kg CO2/kg CODremoved is produced by changing to aerobic sludge digestion, which equates for a typical 100,000 EP plant to an additional production of over 10 t CO2 per day. Preliminary cost estimates confirm that the largely anaerobic process option is a fully competitive alternative to the mainly aerobic processes used, while achieving the same effluent quality.


2021 ◽  
Vol 43 (1) ◽  
pp. 5-12
Author(s):  
Sniezhkin Yu. ◽  
Zh. Petrova ◽  
V. Paziuk ◽  
Yu. Novikova

In sewage treatment plants, sludge is formed during wastewater treatment, in addition to treated water. They are dumped on silt sites, which occupy large areas and almost all overcrowding. The content of large amounts of minerals and toxic substances in sediments leads to the deterioration of underwater waters and land, which in turn leads to the deterioration of ecology and life in Ukraine. An urgent task in Ukraine is to create a comprehensive processing of sludge, which includes economic, technological, social and environmental aspects. The main methods of sludge disposal are use in agriculture, landfilling, incineration and dumping into the sea or ocean. The country is gradually trying to abandon the burial. European Union countries also process sludge aerobically and anaerobically. During these processes, components of organo-mineral fertilizers are created that can be used in agriculture. As fertilizers, sludge is composted, stabilized and pasteurized. Combustion of sludge allows to obtain a substitute for coal and oil. To increase the heat of combustion and improve combustion parameters to sludge sludge add coal, biomass. Low-temperature pyrolysis of sewage sludge and household waste, which allows to obtain "crude oil". One of the methods is processing in biogas plants to obtain both biogas and environmentally friendly fertilizers. To increase the efficiency of treatment and reduction of sludge disposal of used stagnation-ments vermiculture. Analysis of the literature allows us to conclude that there are methods of disposal of sludge, which have become widespread in various countries around the world, such as fertilizers, alternative fuels, landfills and others. When disposing of sludge, it is possible to produce biogas, electricity and heat, which reduces energy costs for the process.


Proceedings ◽  
2020 ◽  
Vol 51 (1) ◽  
pp. 28
Author(s):  
Dariusz Boruszko ◽  
Ada Wojciula

Sewage sludge is a by-product of the municipal wastewater treatment process. The amount of sewage sludge generated in treatment plants in Poland and other European countries is constantly growing. Due to the growing environmental awareness, legal requirements are being established that require the appropriate treatment of sludge before it can be used for natural purposes. Therefore, operators are looking for the best solutions to ensure proper sewage sludge preparation. More and more ATAD (auto-thermophilic sewage sludge stabilization) installations are being built in Poland, which allow for simultaneous stabilization and hygienization of sludge. However, this process contributes to the formation of leachate, which is discharged into the biological reactors of municipal sewage treatment plants. The leachate after the ATAD process has a complex organic substance and is characterized by large loads of total nitrogen and total phosphorus. Biological wastewater treatment processes can be ineffective for such specific pollutants returned in ATAD leachate. Thus far, no research has been undertaken to analyze the problem presented.


1995 ◽  
Vol 31 (5-6) ◽  
pp. 97-104 ◽  
Author(s):  
K. L. Stadterman ◽  
A. M. Sninsky ◽  
J. L. Sykora ◽  
W. Jakubowskii

To determine the fate of Cryptosporidium parvum oocysts during wastewater treatment, a model of an activated sludge treatment plant was designed with a flow of 17 ml/min and a detention time of 6 hours. Samples of raw sewage were seeded with oocysts and primary and secondary effluents were analyzed for C. parvum using an immunofluorescent technique. To compare removal efficiencies of oocysts by various wastewater treatment processes, raw sewage, activated sludge, trickling filter and biodisc effluents were seeded with oocysts and settled for 2 hr and for the respective detention times. Sludge produced by a wastewater treatment plant and anaerobically digested at 37° C in a laboratory digester was also seeded with C. parvum oocysts. Oocyst inactivation was measured by excystation and direct counts. Removal of oocysts in primary and secondary sedimentation averaged 83.4% and 90.7% respectively. The total oocyst removal in sewage treatment averaged 98.6%. In comparison with other treatment processes, activated sludge had the maximum oocyst removal efficiency at 92%. The anaerobic digestion process inactivated 90% of the oocysts within four hours of exposure. 99.9% of the oocysts were eliminated by anaerobic digestion after 24 hours. This demonstrates that the activated sludge process and anaerobic digestion can be effective for the removal and inactivation of C. parvum oocysts.


Author(s):  
Zbigniew Mucha ◽  
Jerzy Mikosz

Abstract Most studies on the impact of reject waters recycled from sludge processing in the multi-phase activated sludge process focus on anaerobic sludge treatment in large wastewater treatment plants, leaving apart the processes of aerobic sludge stabilization often used in smaller facilities in rural and suburban areas. The article presents the results of tests carried out in three small and medium-sized wastewater treatment plants with biological removal of biogenic compounds that use aerobic stabilization to process sludge. The research concerned the quantity and quality of reject waters generated in the process of aerobic stabilization and dewatering of sewage sludge and their impact on the multi-phase activated sludge process. The results showed that the average volume of generated reject waters ranged from 3.2 to 5% of the incoming wastewater volume. The average share of organic compounds and total nitrogen loads contained in reject waters did not usually exceed 5–10% of the loads in raw wastewater but reached almost 50% in the case of total phosphorus. Studies indicated that the composition of the supernatant from aerobic stabilization is strongly dependent on the course of the process. The best quality was obtained for cyclic operation of the aerobic stabilization tank with 16 h of aeration and 8 h of settling. The results also showed the negative impact of sudden discharges of reject waters from sludge processing to a multi-phase biological reactor, which can be reduced by using an appropriate equalization tank and pretreatment of the side stream to reduce the recirculation of phosphorus.


2020 ◽  
Vol 15 (2) ◽  
pp. 142-151
Author(s):  
Peter Lukac ◽  
Lubos Jurik

Abstract:Phosphorus is a major substance that is needed especially for agricultural production or for the industry. At the same time it is an important component of wastewater. At present, the waste management priority is recycling and this requirement is also transferred to wastewater treatment plants. Substances in wastewater can be recovered and utilized. In Europe (in Germany and Austria already legally binding), access to phosphorus-containing sewage treatment is changing. This paper dealt with the issue of phosphorus on the sewage treatment plant in Nitra. There are several industrial areas in Nitra where record major producers in phosphorus production in sewage. The new wastewater treatment plant is built as a mechanicalbiological wastewater treatment plant with simultaneous nitrification and denitrification, sludge regeneration, an anaerobic zone for biological phosphorus removal at the beginning of the process and chemical phosphorus precipitation. The sludge management is anaerobic sludge stabilization with heating and mechanical dewatering of stabilized sludge and gas management. The aim of the work was to document the phosphorus balance in all parts of the wastewater treatment plant - from the inflow of raw water to the outflow of purified water and the production of excess sludge. Balancing quantities in the wastewater treatment plant treatment processes provide information where efficient phosphorus recovery could be possible. The mean daily value of P tot is approximately 122.3 kg/day of these two sources. The mean daily value of P tot is approximately 122.3 kg/day of these two sources. There are also two outflows - drainage of cleaned water to the recipient - the river Nitra - 9.9 kg Ptot/day and Ptot content in sewage sludge - about 120.3 kg Ptot/day - total 130.2 kg Ptot/day.


2007 ◽  
Vol 2 (1) ◽  
Author(s):  
Petia Mijaylova Nacheva ◽  
G. Moeller-Chávez ◽  
E. Ramírez-Camperos ◽  
L. Cardoso-Vigueros

The tropical regions have specific problems associated with high pathogenic density in the sewage sludge. The aim of this study was to select an adequate sludge stabilization and valorization system comparing the performance of four technologies: anaerobic stabilization without heating, aerobic stabilization, alkaline treatment with lime and aerobic composting. The study was performed in a pilot plant which was built and operated during six months. The main problem for the beneficial use of the sludge was its pathogenicity. All the systems allowed obtaining stabilized products which met the bacteriological criteria for some kind of use. The compost and the alkalinized sludge were bacteriologically safe for use without restrictions in accordance with the Mexican regulations. The accomplishment of the parasitological criteria for use was however impossible with the anaerobic and with the aerobic systems. The compost obtained at 55-60°C with 25d aeration time and the alkaline sludge fulfill the criteria established by for forest and agriculture use and for soil conditioning. The composting could reach the requirements for unrestricted use when operated at temperatures 65-70°C during 45 days which makes it the most adequate sludge treatment system for hot climate regions.


1987 ◽  
Vol 22 (3) ◽  
pp. 437-443 ◽  
Author(s):  
N. Kosaric ◽  
Z. Duvnjak

Abstract Aerobic sludge from a municipal activated sludge treatment plant, sludge from a conventional municipal anaerobic digester, aerobic sludge from an activated sludge process of a petroleum refinery, and granular sludge from an upflow sludge blanket reactor (USBR) were tested in the deemulsification of a water-in-oil emulsion. All sludges except the last one, showed a good deemulsification capability and could he used for a partial deemulsification of such emulsions. The rate and degree of the deemulsifications increased with an increase in sludge concentrations. The deemulsifications were faster at 85°C and required smaller amounts of sludge than in the case of the deemulsifications at room temperature. An extended stirring (up to a certain limit) in the course of the dispersion of sludge emulsion helped the deemulsification. Too vigorous agitation had an adverse effect. The deemulsification effect of sludge became less visible with an increase in the dilution of emulsion which caused an increase in its spontaneous deemulsification.


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