scholarly journals Statistical analysis of the effluent quality of 231 on-site sanitation facilities in France monitored during a 6-year period

2019 ◽  
Vol 80 (2) ◽  
pp. 203-212
Author(s):  
L. Olivier ◽  
V. Dubois ◽  
Y. LeGat ◽  
C. Boutin
Keyword(s):  
Loading Rate ◽  
Oxygen Demand ◽  
Operating Conditions ◽  
Treated Wastewater ◽  
Explanatory Variables ◽  
Effluent Quality ◽  
Wastewater Samples ◽  
Sanitation Systems ◽  
Log Linear

Abstract On-site wastewater treatment systems are approved by the French regulation based on the results of platform tests following the European standard NF EN 12566-3. In addition to this approval for the treatment system, at least 90% of outlet concentrations have to be below 30 mg L−1 for total suspended solids (TSS) and 35 mg L−1 for biochemical oxygen demand. The aim of this study is to evaluate the effluent quality of these treatment systems on site, i.e. under real operating conditions, and to assess their performances. Between 2011 and 2016, 1,286 treated wastewater samples were taken from 231 on-site sanitation facilities in France. Data collected are heterogeneous and a robust statistical methodology (using a generalized log-linear model) was used to study the effects of four explanatory variables (treatment systems, loading rate, aging and sampling methods) on the distribution of treated wastewater concentrations. The model calculates median outlet concentrations depending on the effects identified. Its application allowed studying and comparing the outlet median concentrations of 21 on-site sanitation systems classified into nine categories and three groups. Four treatment systems out of the 21 monitored showed TSS median outlet concentrations below 10 mg L−1 and four treatment systems have TSS medians higher than the regulatory threshold of 30 mg L−1.

DECOLOURIZATION AND COD REMOVAL OF WASEWATER FROM ETHANOL PRODUCTION PROCESS FROM MOLASSES BY COAGULANTION USING INORGANIC ALUM

2010 ◽  
Vol 13 (3) ◽  
pp. 92-102
Author(s):  
Trung Duc Le
Keyword(s):  
Ethanol Production ◽  
Oxygen Demand ◽  
Cod Removal ◽  
Treated Wastewater ◽  
Treatment Processes ◽  
Physico Chemical ◽  
Biological Methods ◽  
Treatment Step ◽  
Main Material

The industrial production of ethanol by fermentation using molasses as main material that generates large quantity of wastewater. This wastewater contains high levels of colour and chemical oxygen demand (COD), that may causes serious environmental pollution. Most available treatment processes in Vietnam rely on biological methods, which often fail to treat waste water up to discharge standard. As always, it was reported that quality of treated wastewater could not meet Vietnameses discharge standard. So, it is necessary to improve the treatment efficiency of whole technological process and therefore, supplemental physico-chemical treatment step before biodegradation stage should be the appropriate choice. This study was carried out to assess the effect of coagulation process on decolourization and COD removal in molasses-based ethanol production wastewater using inorganic coaglutant under laboratory conditions. The experimental results showed that the reductions of COD and colour with the utilization of Al2(SO4)3 at pH 9.5 were 83% and 70%, respectively. Mixture FeSO4 – Al2(SO4)3 at pH 8.5 reduced 82% of colour and 70% of COD. With the addition of Polyacrylamide (PAM), the reduction efficiencies of colour, COD and turbidity by FeSO4 – Al2(SO4)3 were 87%, 73.1% and 94.1% correspondingly. It was indicated that PAM significantly reduced the turbidity of wastewater, however it virtually did not increase the efficiencies of colour and COD reduction. Furthermore, the coagulation processes using PAM usually produces a mount of sludge which is hard to be deposited.

scholarly journals Efficiency and Technological Reliability of Contaminant Removal in Household WWTPs with Activated Sludge

2021 ◽  
Vol 11 (4) ◽  
pp. 1889 ◽  
Author(s):  
Agnieszka Micek ◽  
Krzysztof Jóźwiakowski ◽  
Michał Marzec ◽  
Agnieszka Listosz ◽  
Tadeusz Grabowski
Keyword(s):  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Pollutant Removal ◽  
Treated Wastewater ◽  
Contaminant Removal ◽  
Nitrogen And Phosphorus ◽  
Wastewater Samples ◽  
Polish Law

The results of research on the efficiency and technological reliability of domestic wastewater purification in two household wastewater treatment plants (WWTPs) with activated sludge are presented in this paper. The studied facilities were located in the territory of the Roztocze National Park (Poland). The mean wastewater flow rate in the WWTPs was 1.0 and 1.6 m3/day. In 2017–2019, 20 series of analyses were done, and 40 wastewater samples were taken. On the basis of the received results, the efficiency of basic pollutant removal was determined. The technological reliability of the tested facilities was specified using the Weibull method. The average removal efficiencies for the biochemical oxygen demand in 5 days (BOD5) and chemical oxygen demand (COD) were 66–83% and 62–65%, respectively. Much lower effects were obtained for total suspended solids (TSS) and amounted to 17–48%, while the efficiency of total phosphorus (TP) and total nitrogen (TN) removal did not exceed 34%. The analyzed systems were characterized by the reliability of TSS, BOD5, and COD removal at the level of 76–96%. However, the reliability of TN and TP elimination was less than 5%. Thus, in the case of biogenic compounds, the analyzed systems did not guarantee that the quality of treated wastewater would meet the requirements of the Polish law during any period of operation. This disqualifies the discussed technological solution in terms of its wide application in protected areas and near lakes, where the requirements for nitrogen and phosphorus removal are high.

scholarly journals Impact of Partially Treated Wastewater on Downstream Water Quality of Notwane River in Botswana

2018 ◽  
pp. 1-9
Author(s):  
Gilbert K. Gaboutloeloe ◽  
Gugu Molokwe ◽  
Benedict Kayombo
Keyword(s):  
Water Quality ◽  
Pearson Correlation ◽  
Oxygen Demand ◽  
Ammonia Nitrogen ◽  
Treated Wastewater ◽  
Nitrate N ◽  
River Stretch ◽  
Ph Range ◽  
The Impact

The impact of partially treated wastewater on the water quality of Notwane river stretch in the Gaborone region of Botswana was investigated. Water samples collected at effluent discharge point and three other sampling sites downstream were analyzed for pH, temperature, Biological Oxygen Demand (BOD5), Ammonia-nitrogen (Ammonia-N) and Nitrate-nitrogen (Nitrate-N). Sampling was conducted bi-weekly between February 2013 and April 2013. The ranges of measured parameters were:  pH (7.6-8.5), temperature (22-23ºC), BOD5 (11.2-27.0 mg/l), Ammonia-N (2.4-60.5 mg/l), Nitrate-N (20.6-28.6 mg/l). Analysis of variance, Games-Howel multiple comparisons and Pearson correlation were used to separate variable means. The results signal river non-point pollution due to runoff inflow of organics mainly from land use and domestic waste dumping by nearby dwellings. Temperature, BOD5, and pH range values were all within the Botswana Bureau of Standards (BOBS) limit while the maximum Ammonia-N and Nitrate-N were above BOBS limit by 50.5 mg/l and 6.6 mg/l, respectively. Regulations on indiscriminate waste dumping and discharge standards adherence should be enforced.

scholarly journals Oil refinery wastewater treatment in biofilm reactor followed by sand filtration aiming water reuse

2012 ◽  
Vol 2 (2) ◽  
pp. 84-91 ◽  
Author(s):  
Isabelli N. Dias ◽  
Ana C. Cerqueira ◽  
Geraldo L. Sant'Anna ◽  
Marcia Dezotti
Keyword(s):  
Water Reuse ◽  
Slow Rate ◽  
Combined Treatment ◽  
Oxygen Demand ◽  
Biofilm Reactor ◽  
Oil Refinery ◽  
Treated Wastewater ◽  
Refinery Wastewater ◽  
Oil Refinery Wastewater

Oil refinery wastewater was sequentially treated in a moving-bed biofilm reactor (MBBR) and a slow-rate sand filter (SF) in order to obtain an effluent with adequate characteristics for downstream reverse osmosis (RO) operation. Experiments were conducted in bench scale units and the results showed that the MBBR was able to remove 90% chemical oxygen demand (COD), 75% NH4+, 95% phenols, operating with a hydraulic retention time (HRT) of 9 h. Additional removal of COD (15–40%) and ammonia (30–60%) was achieved in the slow-rate SF that was also effective for removing microorganisms. The silt density index (SDI) of the treated wastewater (4.5) was below the maximum limit recommended for RO operation. The quality of the effluent from the combined treatment system (MBBR+SF) was already adequate for cooling tower make-up. The RO produced an effluent with quality compatible with that required for use in boilers.

scholarly journals Principal Component Weighted Index for Wastewater Quality Monitoring

Water ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 2376 ◽  
Author(s):  
Petr Praus
Keyword(s):  
Principal Component ◽  
Treated Wastewater ◽  
Weighted Index ◽  
Physico Chemical ◽  
Wastewater Quality ◽  
Total Variability ◽  
Wastewater Samples ◽  
Quality Indexes ◽  
Component Scores

The quality of raw and treated wastewater was evaluated using the principal component weighted index (PCWI) which was defined as a sum of principal component scores weighted according to their eigenvalues. For this purpose, five principal components (PCs) explaining 88% and 83% of the total variability of raw and treated wastewater samples, respectively, were extracted from 11 original physico-chemical parameters by robust principal component analysis (PCA). The PCWIs of raw and treated wastewater were analyzed in terms of their statistical distributions, temporal changes, mutual correlations, correlations with original parameters, and common water quality indexes (WQI). The PCWI allowed us to monitor temporal wastewater quality by one parameter instead of several. Unlike other weighted indexes, the PCWI is composed of independent variables with minimal information noise and objectively determined weights.

A Decade of Change at West-Southwest Sewage Treatment Works, Chicago, Illinois, U.S.A.

1984 ◽  
Vol 16 (12) ◽  
pp. 555-571
Author(s):  
Nicholas J Melas ◽  
Raymond R Rimkus
Keyword(s):  
Suspended Solids ◽  
Sewage Treatment ◽  
Oxygen Demand ◽  
Ammonia Nitrogen ◽  
The West ◽  
West Side ◽  
Effluent Quality ◽  
Effluent Standards ◽  
Solids Processing

The Metropolitan Sanitary District of Greater Chicago's West-Southwest Sewage Treatment Works consists of the West Side Treatment Works, an Imhoff facility placed in operation in 1930, and the Southwest Sewage Treatment Works, an activated sludge plant placed in operation in 1939. This paper focuses on the decade of “1970's” and examines changes in plant operating procedures along with plant additions and improvements that were implemented in order to meet stringent water quality and effluent standards. The effect of the energy crisis and the measures taken at the West-Southwest Sewage Treatment Works to lessen its impact are reported. Over the study period, very costly and energy intensive solids processing operations were either curtailed or eliminated. New and innovative processes of sludge handling were developed and implemented. The net effect of these changes in solids processing coupled with modifications in the secondary wastewater treatment operations have resulted in a significant improvement in the effluent quality of the plant. In the early seventies, the effluent concentration for suspended solids, biochemical oxygen demand, and ammonia-nitrogen were 30, 23, and 12 mg/l, respectively; the corresponding values for these parameters in 1981 averaged 6, 6, and 1.4 mg/l.

Test on Microfiltration as a Tertiary Treatment Downstream of Fixed Bacteria Filtration

1992 ◽  
Vol 25 (10) ◽  
pp. 219-230 ◽  
Author(s):  
B. Langlais ◽  
Ph Denis ◽  
S. Triballeau ◽  
M. Faivre ◽  
M. M. Bourbigot
Keyword(s):  
Suspended Solid ◽  
Sewage Water ◽  
Poor Quality ◽  
Operating Conditions ◽  
Secondary Effluent ◽  
Tertiary Treatment ◽  
Effluent Quality ◽  
Filtration Cycle ◽  
Highly Sensitive

Conventional methods of disinfecting sewage water are all highly sensitive to variations in the effluent quality upstream of the disinfection stage. Microfiltration was tested as a tertiary treatment downstream of biofiltration, simulating very poor biofilter efficiency, to test the limits of the microfiltration process. Despite the poor quality of the secondary effluent (COD between 100 and 400 mgO2/l, BOD5 between 30 and 150 mgO2/l and suspended solid concentrations between 15 and 90 mg/l), the microfiltration process (filtration level : 0.2 µm) eliminated all faecal germs and tenia and ascaris eggs. The total elimination of free amoeba cysts still needs to be confirmed. With the COD and BOD5 reduced by an average of 60 and 70% respectively, the effluent quality is equivalent to level e after microfiltration (COD: 90 mgO2/l and BOD5=30 mgO2/l on samples averaged over 24 hours). Turbidity, measured instead of suspended solids at outlet from the microfilter, was 99% eliminated. The colour remained between 50 and 150 mg Pt.Co/l. Under the operating conditions applied, the minimum filtration cycle was 72 hours for a minimum permeate flow of 80 l/h/m2 of membrane.

Analysis of Requirements for Effluent Quality and their Impact on Status of Rivers

2017 ◽  
Author(s):  
Regimantas Dauknys ◽  
Aušra Mažeikienė
Keyword(s):  
Organic Pollutants ◽  
Total Nitrogen ◽  
Total Phosphorus ◽  
Good Condition ◽  
Ecological Status ◽  
Treated Wastewater ◽  
Effluent Quality ◽  
Lithuanian Rivers ◽  
The Impact

The article analyses Lithuanian rivers, 32 of which have been selected as non-complying with the require-ments of good condition. Furthermore, 15 discharge facilities that discharge wastewater to the aforementioned rivers from agglomerations with population equivalent (PE) greater than 2,000 have been selected. The assessment of the quality of treated wastewater according to the allowable impact on the reception facility has been carried out and has been compared with the currently regulated minimum allowable values of concentrations of pollutants. The analysis of the impact of quality of treated wastewater on the ecological status of rivers has been presented. It has been established that the pollution of rivers would be decreased by an average 8% (organic pollutants and total nitrogen) and by 22% (total phosphorus), if the allowable concentrations of pollutants according to the impact on the reception facility were ensured in the analysed treatment plants with PE greater than 10,000.

Experimental Study on Treatment of Wastewater Containing Oil and Polyacrylamide by Aerobic and Anaerobic Bacteria

2014 ◽  
Vol 675-677 ◽  
pp. 539-542 ◽  
Author(s):  
Guang Meng Ren ◽  
Yu Pan ◽  
Xiu Min Yang ◽  
Yan Yun Qiao ◽  
Hong Wei Li ◽  
...  
Keyword(s):  
Anaerobic Bacteria ◽  
Biofilm Reactor ◽  
Operating Conditions ◽  
Moving Bed Biofilm Reactor ◽  
Moving Bed ◽  
Effluent Quality ◽  
Sulphate Reducing Bacteria ◽  
Reducing Bacteria ◽  
Aerobic And Anaerobic

Wastewater containing oil and polyacylamide is a kind of organic wastewater, which is hard to treat. The combined process of moving-bed biofilm reactor and sulphate-reducing bacteria was used to treat the wastewater. Operating conditions of moving-bed biofilm reactor and sulphate-reducing bacteria were studied. Results indicate that the oil removal efficiency by moving-bed biofilm reactor can reach above 90% with 9 hours hydraulic retention time at 25°C, but it has no effect on polyacylamide. Sulphate-reducing bacteria can degrade polyacylamide, and polyacylamide conversion is about 50% at 37°C with 4 days culture time and 9ml inoculation size. The effluent quality of wastewater containing oil and polyacylamide can meet requirements of the first level in integrated wastewater discharge standard.

Treatment of agricultural drainage water via downflow hanging sponge system for reuse in agriculture

2013 ◽  
Vol 13 (2) ◽  
pp. 403-412 ◽  
Author(s):  
Amr Fleifle ◽  
Ahmed Tawfik ◽  
Oliver C. Saavedra ◽  
Mohamed Elzeir
Keyword(s):  
Suspended Solids ◽  
Oxygen Demand ◽  
Drainage Water ◽  
Treated Wastewater ◽  
Agricultural Drainage ◽  
Organic Loading ◽  
Effluent Quality ◽  
Loading Rates ◽  
Agricultural Drainage Water ◽  
Negative Effect

Treatment of agricultural drainage water (ADW) in a down-flow hanging sponge (DHS) reactor has been investigated for a period of 1 y. The reactor was operated at different hydraulic retention times (HRTs) of 5.26, 2.63, and 1.5 h and corresponding organic loading rates (OLRs) of 2.01, 1.86, and 4.43 kg COD/m3 d, respectively. The results obtained indicated that, decreasing the HRT from 5.26 to 1.5 h negatively affected the chemical oxygen demand (COD) removal. Average COD percentage removal values dropped from 89.3 ± 5.4 to 72.2 ± 16% respectively. Total suspended solids (TSS) concentrations were reduced by 85.5 ± 8.3, 90.4 ± 2.1, and 91.4 ± 4.9 at HRTs of 5.26, 2.63, and 1.5 h, respectively. However, the nitrification efficiency was slightly decreased from 85.2 ± 17.4 to 82 ± 11.4% by decreasing the HRT from 5.26 to 1.5 h and increasing the OLR from 2.01 to 4.43 kg COD/m3 d, respectively. Likewise, reducing the HRT from 5.26 to 1.5 h exerted a slight negative effect on the removal of the total phosphorus (TP). Based on these results it is recommended to operate such a system at a HRT of 2.63 h and OLR not exceeding 2.0 kg COD/m3 d for providing an effluent quality complying with the standards regulating the use of treated wastewater for agricultural purposes.

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