Correct functioning of sewage disposal and treatment systems depends prevalently on the proper design, construction and subsequent proper operation. In designing sewer systems the most important parameter affecting determination of pipe diameters is a reliable sewage volume, frequently determined per 1 inhabitant as a unit sewage outflow in dm3∙M-1∙d-1. The investigations were conducted to determine unit sewage outflows from rural sewerage system in Koszyce per year, with respect to individual months and days of the week in 2002-2005. The volume of sewage flowing out of sanitary sewer system in Koszyce was determined on the basis of measurement conducted on the supply canal to the sewage treatment plant in Włostowice. Koszyce municipality is situated in the malopolskie province, proszowicki poviat. Currently the sewer system in the municipality area is utilised by 1673 inhabitants. Sewage is discharged by 280 households. Mean daily sewage outflows (at the rainless weather) during the period of research fluctuated between 58.7 in 2005 and 75.1 dm3∙M-1∙d-1 in 2003. During the whole period of investigations mean unit outflow was 67.1 dm3∙M-1∙d-1, with standard deviation 11.5 dm3∙M-1∙d-1. and irregularity coefficient 1.34. The values of average unit sewage outflows in individual years corresponded to unit values of water consumption in ...
Two methods of assessment of the effectiveness of sewage treatment plant operationwere presented in the paper: first one – with the use of the reliability theory, and second one, with the use of the statistical quality control process by means of control charts. The analysis was carried out in a sewage treatment plant located in the village of Rokiciny Podhalańskie. The sewage treatment plant works in the A2/O system. The evaluation of effectiveness of the sewage treatment was made for the following pollutants: BOD, ammonia nitrogen, total nitrogen and total phosphorus. The analysis showed the proper work of the sewage treatment plant for BOD and total phosphorus. The calculated reliability level were 93,3% and more than 99,9%. For total nitrogen the reliability level was lower: more than 46% for empirical distribution and more than 37% for normal distribution. This was caused by the character of inflow sewage. The analysis of control chart showed the stable work in reducting organic pollutants, and in spring and summer period unstable work for ammonia nitrogen and total phosphorus. Only once a disturb of process effectiveness of total nitrogen changes caused probably by inflow of storm water to the sewage system was observed. ...
Industrial effluents have currently constituted the main portion of a total volume of generated sewage, however a tendency to diminish their quantity has been observed. Treatment of specific sewage faces serious technological problems due to the special character of production in the manufacturing plants, which affects the irregularity and amount of pollutants. Considerable quantitative and qualitative variability of the generated sewage is perceivable even at the plants with the same profile of production. Therefore, it is necessary to identify precisely the properties of effluents produced not only by the same branches of industry but even by single factories. Considering the food sector enterprises, the least amount of literature data is available on physicochemical properties of effluents generated by confectionery industry. Therefore, the study aims to characterize the effluents produced by confectionery factories and compare them with the properties of sewage from other food manufacturing plants. The main emphasis was put on the analysis of the results of research on confectionery effluent treatment in a model bioreactor with activated sludge. The main characteristics of sewage generated by confectionery factories are considerable fluctuations of pollutant quantities, which is a frequent cause of observed operational problems with the treatment plant process line. Compared ...
The article presents evaluation of sewage treatment plant in Wadowice operation on the basis of pollutants’ reduction in the period from January 2003 to December 2005. Additional aim was analysing amount of inflowing sewage in the research period. Evaluation of operation capacity was based on reduction size of 5 chosen pollutants’ indexes: BOD5, COD, total suspended solids, general nitrogen and general phosphorus. Values of above mentioned pollutants’ indexes in treated sewage were compared to values from water-law permission given by Wadowice Starost for Wadowice Waterworks and Sewerage Utility Sp. z o. o. from 28.03.2006. Results of analyses of treated sewage composition show, that mean values of BOD5, COD, total suspended solids, general nitrogen and general phosphorus are lower than the admissible values from water-law permission. In the case of BOD5 mean value on the outflow (14,0 mgO2·dm-3) is almost 7% lower than the admissible value (15 mgO2·dm-3), COD (mean value 89,15 mgO2·dm-3) – 28,7% lower than the admissible value (125 mgO2·dm-3), total suspended solids (mean value 27,27 mg·dm-3) – 22,1% lower than the admissible value (35 mg·dm-3), general nitrogen (mean value 22,17 mgNgen·dm-3) – 26,1% lower than the admissible value (30 mgNgen·dm-3) and general phosphorus (mean value 1,26 mgPgen·dm-3) – ...
The aim of the research was defining temperature changes of sewage in sewerage system and in open biological reactor under the influence of atmospheric air temperature. The literature connected with sewage treatment doesn’t give unequivocal information regarding influence of air temperature on sewage temperature in the canalisation. Some authors claim that such a relationship doesn’t occur. The research carried out on the area of sewage treatment plant in Koszyce commune showed, that important relationship exists between mean daily atmospheric air temperature (tair) and mean daily temperature of sewage in sewerage system (tsew). This relationship may be with high accuracy (R2=0,78, p<0,001)described by a cubic polynomial equation: tsew = -0,0011·(tair)3 + 0,0232·(tair)2 + 0,3704·tair + 9,0554. In the research period, mean daily temperature of sewage in sewerage system was going under big fluctuations, from 6,35 to 17,56°C. Changes of sewage temperature in the collector during the day ranged between 0,35°C and 4,60°C. In the winter period, with mean daily air temperature under 5°C, sewage temperature in the canalisation lowered under 10°C, reaching its minimal value of 5,37°C. In biological reactor, which was built as a reinforced concrete open reservoir, mean daily sewage temperature ranged between 5,68 and 21,04°C. Whereas in the ...
The paper presents the results of the research regarding the amount of sewage inflowing by the sewerage system and the amount of sewage brought to the collective sewage treatment plant in Nowe Brzesko with the sanitation vehicle. The analyzed treatment plant is located in the area of Nowe Brzesko town in Nowe Brzesko Economic Area on the left bank of the Vistula River. Domestic sewage from 250 buildings are drained into this object. The analysis of the amount of sew-age was carried out in the period from January 2005 to December 2007. In this period the amount of sewage inflowing and brought in each month was defined in order to compare this amount with the designed one. Moreover, the paper presents the frequency of the defined amounts of inflowing sewage occurrence, as well as the probability of their occurrence. After data analysis, it was stated that the tested object is hydraulically under-loaded. In 2005 the actual amount of treated sewage constituted only 20,4% of the established treatment plant capacity, in 2006 this amount was 22% and in 2007 – 26,7%. In the period of 3 years high irregu-larity of the amount of incoming and brought sewage in each month was ...
The article presents the thorough description of the vertical flow sand filters. The construction of sand filters was also presented and materials used for building filters were described. In the next part, capacities of sewage treatment in the vertical flow sand filters were presented. Vertical flow sand filters are mainly used as the second step of sewage treatment after septic tanks or after Imhoff tanks, as well as the third step after biological treatment processes when the high quality and stable outflow is required. Sand filters are useful for treatment sew-age from single households and from the group of houses, but they also can be used in bigger sewage treatment plants for the public utility objects. The article ends with the summary and conclusions where it is ascertained that the vertical flow sand filters are very good solution regarding household sewage treatment plants, in the areas where the combined sewerage system can-not be applied. Moreover the efficiency of sewage treatment in these objects is high. ...
The paper presents the reliability of the sewage treatment plant operation for Tuchów commune. The research was carried out from January 2005 to December 2006. The following sewage pollution ratios were physico-chemically analyzed: BOD5, CODCr, total suspended solids. In order to define the proper treatment plant's operation, the reliability coefficient was calculated (RC) for each of the tested indexes. The empiric reliability was presented. The amount of transgresions of the admissible index values presented in the water-law permis-sion was described. Moreover, the efficiency of the ratios' decrease in the tested period was defined.The carried out research showed the high efficiency of the pollutants' amount decrease: BOD5 - 90,7%, CODCr - 86,6%, total suspended solids - 90,5%. The calculated Reliability Coefficients RC of the analyzed indexes amounted respectively: for BOD5 - 0,52, for CODCr - 0,31 and for total sus-pended solids 0,62. ...
The paper presents the efficiency of the sewage treatment based on the ex-ample of the sewage treatment plant for Krynica-Zdrój. The research was carried out from January 2006 to December 2007. The following sewage pollution indexes were physico-chemically tested: BOD5, CODCr, total suspended solids, general ni-trogen and general phosphorus. The reliability coefficient (RC) was calculated for each of the analyzed indexes. The amount of the transgressions of the admissible index values in relation to the water law permission was defined. Moreover, the ef-fectiveness of the indexes' decrease in the tested period was analyzed. Additionally the amount of sewage flowing into the treatment plant in each months of the tested period was presented. The carried out research showed the high efficiency of the pollutants' removal. The average reduction of the tested indexes balanced on the level of: BOD5 - 95,03%, CODCr - 90,98%, total suspended solids - 94,76%, gen-eral nitrogen - 79,79%, general phosphorus - 63,5%. ...
The aim of the research was to evaluate the pollutants' concentration in the household sewage drained from the rural or rural-urban districts located in Lesser Poland Voivodeship. The research was based on the analysis of 140 raw sewage samples taken from 34 sewerage systems in the period of 2000-2009. Val-ues of five selected pollution indexes were analyzed: BOD5, COD, total suspended solids, general nitrogen and general phosphorus. The results were compared to the amounts presented in the common literature on the sewage treatment. The research showed that the average values of the pollution indexes in the household sewage drained from the rural and urban-rural districts in Lesser Po-land Voivodeship differ from the values presented in the literature. The biggest difference was found in the case of the general nitrogen (value 48% higher) and COD (value 4,4% higher). However the average concentration of the general phosphorus, 11 mgP•dm-3, turned out to be 45,8% lower than the average value presented in the literature. The maximum values of BOD5, COD, total suspended solids and general nitrogen in the tested sewage were much higher than the maxi-mum values in the analyzed references. On the basis of the relationships between the average values ...
The aim of the research was to determine the rain water volume which infiltratesthrough the holes in the sewage chambers inside the pipes of the separatesewer system. Incorrect paving or the sewer chambers envois cause the chambers'surfaces deepen in the area surface. The water which flows down during the rainfallor the snow melt, infiltrates inside the chamber through the cleavages, butmainly through the technical holes in the hatches. These holes are used for the keyor the lever to raise or to open the lid of the hatch.The field analyses showed that many sewage chambers are made incorrectly.In many cases the hatch's lid is located from 10,6 to 38,3 mm below thearea surface. It causes the rainfall or the snowmelt water to overflow through thecleavages or through the holes in the hatch to the sewage chamber. On the basisof the laboratory analyses, it was ascertained that the inflow of the precipitationwater to the sewage chamber, by the hole used to raise the lid, can be described bythe following equation: Q = 25 · h2 + 7,7679 · h, in which h is the immersion of thehatch below the area surface.The research showed that with the long-term rainfalls or the surface flowsrelated ...
The performed study aimed to determine the effect of sewage temperature in bioreactors on pollution discharges measured by the BOD5, COD and total ni-trogen indexes. The research was carried out in a municipal sequential batch re-actor (SBR) treatment plant. The discussed treatment plant is located in Książ Wielki commune in Miechów district in Lesser Poland voivodeship. Households from two villages: Książ Wielki and Wielka Wieś discharge their sewage into the analysed treatment plant. An average of 100 to 110 m3•d-1 of sewage constituting nearly 50% of the designed hydraulic load of this object was discharged into the treatment plant during the study period. Temperature measurements and sewage sampling for physicochemical analyses were performed for 24 months in 2007 and 2008. Twenty four sewage samples were collected with a frequency of once per month. The lowest sewage temperature in the bioreactor during the study period was 7.1°C, whereas the highest temperature reached 18.8°C. Therefore, the sew-age temperature amplitude in the bioreactor was 11.7°C. Low sewage temperature below 10°C occurred from December to April. Lower efficiency of neutralisation of the 3 analysed pollution indexes was observed in this period. The carried out research revealed average relationship between the sewage temperature in the ...
The paper presents the analysis of research results on the unit pollution loads in the effluent from two public utility buildings - schools. Both school build-ings are located in the typical rural communes in Lesser Poland Voivodeship. During the research period the first school in Rajbrot was attended by 365 students whereas the number of students in the second school in Imbramowice reached 100. The objective of this study was to determine the unit load for the following pollution indexes: BOD5, COD, total suspended solids, total nitrogen and total phosphorus. The research period was 36 months in 2006-2008. During this period 36 samples of the sewage runoff (raw sewage) from each object were collected on average once a month. Based on the collected data the following characteristic values of unit pollution loads were defined: minimum, maximum and arithmetic mean. The research results were compared to information presented in the litera-ture on the unit pollution loads in household sewage. Updated data on pollution loads in sewage from the school buildings should contribute to the correct design or selection of individual sewage treatment systems based on the population equivalent (PE) for objects of this type wherever there are no data on physico-chemical ...
To designing of the pressure sewage systems, built of pipes PE and PVC, essential are hydraulic calculations, which would consider physical properties of sewage. In the applying norm [PN-EN 1671 2001], missing right formulae which would consider these properties. In connection with it, in this article, remained introduced methodology and results of experimental researches, which was a pur-pose, determine empirical relation for calculate linear losses coefficients in pipes PE and PVC, during the pressure flow sewages. Showed that the flow of sewage had character in pipes of PVC and PE of flow in pipes hydraulic smooth, and linear losses coefficients s determined from experimental research in pipes of PVC and PE is taking comparable value, which in the range for the recommended speed v are bigger to value sBlasius calculated from the Blasiusa formula.
...
The aim of the study was to determine the extent to which heavy rainfall, that occurred in 2010, affected the infiltration into the selected sewage treatment plants in the Małopolskie voivodeship. The research was conducted in four separate sewer systems, located in poviats adjacent to the city of Kraków, dis-charging sewage to mechanical-biological treatment plants with a capacity below 1000 m3•d-1. The amount of sewage and extraneous water in the average wet year (2008) were used as control.As a result of heavy precipitation in 2010 the sewer system A received 18 539 m3 more extraneous water than in 2008 (increase by 343%), the sewer sys-tem B - 22 822 m3 (increase by 163%), the sewer system C - 109 715 m3 (increase by 248%) and the sewer system D - 30 796 m3 (increase by 303%). Heavy precipitation in 2010 caused the increase of infiltration and inflow by 264% on average in all studied sewer systems compared to the average wet year. As the result of precipitation, whose annual total in 2010 was higher by 65% than the normal value in 2008, there was an increase in the annual share of extraneous water from 5.3 to 19.7% depending on the ...
The paper presents issues concerning the construction and commissioning of a constructed wetland wastewater treatment plant on the example of an object, which was established in 2011 in the village Skorczyce (Lublin province). It was found that the costs of constructing this type of treatment plant pay for itself after about 5 years of operation. Calculated that the cost of materials accounted for 65% of the total investment costs incurred for the installation of the object. The remainder (about 35%) were the costs of services relating to the design and im-plementation of treatment plant and supervision of its construction and commis-sioning. In the first months of treatment plant operation was over 95% efficiency of the elimination of organic pollutants (BOD5 and COD) and total suspended solids removal. Optimum conditions for removal of pollutants were observed in the first bed with vertical flow. During start-up treatment plant the average total phosphorus removal efficiency was 84% and total nitrogen did not exceed 42%, which may be due to inadequate formation of biological membranes and unfavorable conditions for the normal processes of nitrification and denitrification.
...
The aim of the study was to determine the volume of infiltration and inflow within a selected sanitary sewer system by using the moving minimum method. The examined sewer system is located in Kraków County, Lesser Poland Voivodeship. Parasite water inflow into the sewer system was studied in the multiannual period of 2008-2011. Based on the analysis of the research results, obtained using the moving minimum method, it was determined that the infiltration fraction in the annual inflow of contaminated water into the sewer system was from 19.0 to 20.7%, while the fraction of extraneous water - from 19.5 to 31.4%. The largest inflows of extraneous water in the analyzed multiannual period occurred in 2010 (30 210 m3). Due to high total annual precipitation this year was evaluated as very wet. The lowest inflows of extraneous water to the sewer system (15 053 m3) were observed in 2011 (extreme dry year). On the other hand, the largest inflow of infiltration water (20 675 m3) occurred in 2009 (dry year) and the lowest (14 805 m3) - in 2011. The performed research demonstrated a strong correlation between the annual amount of precipitation and the annual volume of parasite water flowing into ...
The paper presents the efficiency of the sewage treatment based on the ex-ample of the sewage treatment plant in Dobczyce. The resarch was based on the analysis of 44 raw sewage and treated sewage from January 2007 to December 2010. Values of five selected pollution indexes were analyzed: BOD5, COD, total suspended solids, general nitrogen and general phosporus. The amount of the transgressions of the admissible index values in relation to the water law permis-sion was defind. The effectiveness of the indexes' decrease In the tested period was analyzed. The carried out research showed the high efficiency of the pollutants amount decrease: BOD5 - 98,9%, COD - 97,6%, total suspended solids - 97,6%, general nitrogen - 89,4%, general phosporus - 97,6%. ...
The aim of this study was to determine the extent of the effect of infiltration into a sewerage system during wet weather on the concentration of nitrogen and phosphorus compounds in raw sewage flowing into the treatment plant and in treated sewage discharged into the receiver. The study was conducted in four se-lected sewerage systems located in the Lesser Poland Voivodeship. The results showed that in each of the analyzed cases the concentration of to-tal nitrogen and total phosphorus in raw sewage was reduced by the infiltration into the sewerage system during wet weather. There was no adverse effect of infiltration on the concentration of total ni-trogen in treated sewage discharged into the receiver during wet weather. On the other hand, the research showed that when the share of infiltration in the daily flow increased by 10%, the concentration of total nitrogen was reduced by from 2.7 to 4.8%. The research demonstrated the adverse effect of infiltration on the concen-tration of total phosphorus in treated sewage in the case of objects with low hy-draulic capacity. Sewage flows, increased by infiltration water, caused the removal of activated sludge, containing phosphorus compounds, from bioreactor chambers and funnels of secondary settling tanks. However, ...
The efficiency of sewage treatment in the ground bed under the subsurface sewage disposal field was tested in laboratory conditions using synthetic sewage. The ground bed was composed of mean sand and mean sand with assist layer with chalcedonite. The experiment determined the following indicators: suspended solids, BOD5, COD, total nitrogen, ammonia nitrogen, nitrate nitrogen, nitrite nitrogen, total phosphorus and pH. In the sewage filtered through the ground bed of mean sand as well as through mean sand with assist layer with chalcedonite, increase in the values of nitrite nitrogen and pH was observed. The values other indicators of the treated sewage, was undergo a decrease. The suspended solids, BOD5, COD, total nitro-gen, total phosphorus of the treated sewage, are meeting obligatory standards. The ground bed with mean sand with assist layer with chalcedonite is characterized by a better effectiveness of sewage treatment. ...
The aim of this study was the application of the triangle method for the calculation of the infiltration and inflow volume entering the sanitary sewer system operating in the Cracow County (Lesser Poland Voivodeship). The analyzed, 10 km long, sewer system is made of vitrified clay pipes with diameters of 200, 250 and 300 mm. Infiltration and inflow, also called extraneous water, adversely affect the operation of sewer systems and sewage treatment plants, what in turn may result in water contamination in the receiver. Amount of extraneous water in the inflows to sewer systems should be estimated using the available computational methods and their causes should be eliminated on an ongoing basis. The conducted study showed an alarming amount of extraneous water flowing into the analyzed sewer system, i.e. in 2010 it accounted for 41.1% (40033 m3), in 2011 - 28.7% (22224 m3), while in 2012 - 23.4% (16848 m3) of the total annual volume of polluted water. The volume of infiltration and inflow entering the examined sewer system depended primarily on the frequency of precipitation, and - to a lesser extent - on its annual total amount. Illegal connections of yard inlets or gutters to the sewage drains are ...
The aim of the study was analysis of the reliability of the municipal sewage treatment plant Bioblok PS -50. The sewage treatment plant is in Gruszow in municipality Palecznica in the Malopolska province. Time of research was from 2008 to 2010 year. During this period, collected and analyzed the physico- chemical 18 samples of raw sewage and treated with an average frequency of once every two months in accordance with the reference methods. The evaluation of the effectiveness of contaminant removal in this treatment was determined using the Weibull reliability theory elements. The studies included pollution indicators specified in the authorization issued of law for this object: BOD5, COD and total suspension. Moreover determined regarding the reliability of wastewater nitrogen. On the basis of the assessment of the reliability of operation of the facility in relation to the indicators of the primary group: BOD5, COD and total suspension has been shown that the probability of exceeding the limit values can be from 3 to 8 days in the year. Number of days with possible exceeding of the limit values of indicators of pollution indicates that the test treatment meets the level of technological reliability. With respect to the reliability of ...
The research aimed to learn if and to what extent extraneous waters, occasionally flowing into sanitary sewer system during atmospheric precipitation, change proportions of selected pollution indices which are significant regarding biological sewage treatment. The following proportions between pollution indices should be maintained in the sewage subjected to biological treatment process: COD:BOD5 ≤ 1.8; BOD5:N ≥ 4.0, BOD5:P ≥ 25; COD:P ≥ 3.6. Investigations conducted in two sewer systems located in the Małopolskie voivodeship revealed that extraneous waters infiltrating the intercepting sewers during wet weather negatively affect all proportions between pollution indices. Increasing amount of extraneous waters in sewer systems caused the greatest changes of BOD5:N and BOD5:P proportions. On the basis of conducted research it was found that considerable quantities of nitrogen and phosphorus compounds are supplied to the sewer system with extraneous waters, which in biological denitrification and dephosphatation processes may lead to a deficit of organic compounds causing a necessity to provide an external source of carbon for the reactor chambers, such as methanol, ethanol, acetic acid, glucose or others. During the conducted investigations it was demonstrated that extraneous waters in interceptors cause not only sewage dilution, but also significantly change its chemical composition. ...
The article contains evaluation of functionality of sewage treatment plant in Jasło for multiplicity 2010 - 2014. On the basis of the results raw and cleaned sewage physico-chemical analysis, the efficiency of sewage treatment, coefficient of technological reliability, technological efficiency of sewage treatment and risk of the negative assessment of work of sewage treatment plant, were obtained, for following pollutions indicators: total suspended solids, BOD5, CODCr, total nitrogen and total phosphorus.Based on obtained results its conclude the average reduction of pollution on level below 90%. Only for total nitrogen the average reduction is lower and is on level 77%. Based on other values of indicators of reliability work of sewage treatment plant its conclude that the tested sewage treatment plant may be certified to operate in high quality and the sewage treated by this plant doesn't threaten the collector of the treated sewage. ...
The article contains analysis and evaluation of the impact of clean sewage on sewage treatment plant in Myślenice, in the period 2008 - 201,1 on the physico-chemical composition and water quality of the receiver - river Raba. The analysis conducted based on collected and statistical research: amount and composition of clean sewage and composition of the water receiver in cross-section: Stróże (above of inflow clean sewage) and Osieczany (below of inflow clean sewage). The following pollution index were tested: total suspended solids, BOD5, CODCr, total nitrogen and total phosphorus. Based on obtained results its concluded that in period 2008 - 2011 sewage treatment plant was working properly, what explain quality of clean sewage. What reflected in directly protection of receiver water against pollution. Moreover, based on the results of U Mann Whitney test, concluded that in the both cross-section, composition of the water of Raba river was similar, what explain the results of this test, which didn't show statistically significant differences between average values of concentrations analyzed indicators of pollutions. Based on obtained results its concluded that sewage treatment plant in Myślenice doesn't negatively impact on quality of the water receiver -Raba river. ...
The aim of the study was to determine the influence of the percentage of sewage from septic tanks to the variability of pollutant concentrations in the mixture of sewage undergoing treatment process in the collective sewage treatment plant. The study involved measuring the daily amount of wastewater influent and from septic tanks and determined the percentage of the amount of sewage from septic tanks in relation to the total wastewater being purified. During the 5-year study collected and analyzed 20 samples of sewage, which were made markings indicators: BOD5, COD and total suspension. After the statistical analysis, it was found that with the increase of the share of sewage from septic tanks by 1% increased the value of BOD5 14.6 mgO2•dm-3, increases the value of COD 40.2 mgO2•dm-3 and increases the concentration of total suspension of 21,4 mg•dm-3 in the total mixture of the waste water being purified. ...
The aim of this study was to assess the reliability of two on-site sewage treatment facilities (BCT S-12 and TJ EP-4) serving two school buildings located in rural communes in Małopolska region. The reliability was determined using Weibull reliability method. The research was conducted for 24 months and it involved the collection and analysis of 48 samples of raw and treated sewage from each facility. The analyses included organic and biogenic pollution, i.e. BOD5, COD, and total nitrogen. Reliability assessment revealed the following effectiveness for BCT S-12 facility: 77% for BOD5, 96% for COD and 25% for total nitrogen. For TJ EP-4 facility, the effectiveness was 81%, 88% and 72% for BOD5, COD and total nitrogen, respectively. Both facilities used the activated sludge process and experienced periodic disturbances in the treatment flow that resulted in reduced sewage treatment efficiency. Considering the above, the processes of nitrification and denitrification in the biological reactor should be streamlined to provide more effective removal of organic and nitrogen-based compounds in the investigated facilities. ...
The objective of this research was to compare the amount of extraneous water flowing into selected gravitational separate sewer systems which discharge domestic sewage from the settlement of single-family houses in Poland and France during a year with a standard annual amount of precipitation. The study included a total of four sewer systems, including two operating in Poland and discharging the sewage from settlements near Krakow in the Malopolska Province and two systems operating in France and discharging the sewage from settlements of single-family houses near Lorient, Brittany, Morbihan Department. As part of the analysis, an average daily tributaries of extraneous water into sewers under the research, values of addition and share of this water were compared. Analysis of the research results demonstrated that the hydraulic load of sewer systems with extraneous water does not depend on the age of the sewer system, but mainly on the number of house drains, and to a lesser extent its length. It was also determined that the average daily amount of extraneous water flowing into sanitary sewer systems in wet weather is 0,107 m3·d-1 per 1 sewer connection. The study showed that tributaries of extraneous water into the separate sewer system ...
The two-stage technological system for the treatment of domestic sewage, characterized by an elevated concentration of ammonium nitrogen, consisted of a settling tank and a vertical flow multi-layer filter bed with a sponge-sand filling was analyzed. In the upper part of the filling in the form of spongy polyurethane foams there was the removal of hardly decomposable organic compounds and ammonium nitrogen without the need for additional aeration. In the lower layer of quartz sand, the removal of orthophosphates and pathogenic bacteria took place. After 400 days of operation, multi-layered filter beds achieved high average removal efficiency under variable hydraulic load conditions. The upper 30 cm layer of waste foams used, combined with the 60-cm bottom layer of sand, proved to be very effective in the removal of ammonium nitrogen and organic compounds. The degree of N-NH-4+, CODCr and BOD5 elimination was at 91.6, 77.4 and 91.7% respectively. The 30-cm upper layer of waste foams used combined with the 60-cm lower layer of sand allowed for removal of Escherichia coli in 98.9% on average, whereas coliform bacteria - in 95.0%. ...
