Clarification of Biologically Treated Wastewater in a Clarifier with Suspended Sludge Layer

The article presents the results of an experimental study on the clarification of biologically treated wastewater in a clarifier with a suspended sludge layer. The pilot plant was receiving effluent from trickling filters treating municipal wastewater. An experimental clarifier worked under steady-state conditions considering the influent characteristics and variable operating parameters in terms of flow velocities and height of the suspended layer. From the experimental dependences between different technological parameters it was found that the optimum range of the upward flow velocities providing a dynamic equilibrium of the suspended layer was 0.6–1.4 mm/s. Upward flow velocities below 0.5 mm/s can lead to sludge compaction at the bottom of the unit, while values greater than 1.8 mm/s may cause sludge washout. It was also found that higher suspended layer height values favor higher efficiency of the clarifier and can achieve suspended solids in the discharge of less than 5.0 mg/L; this height should be greater than 0.6 m Technological efficiency of the experimental clarifier was significantly higher than the conventional unit and was comparable with tertiary treatment technologies.

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Removal of Enteric Pathogens from Real Wastewater Using Single and Catalytic Ozonation

Water ◽

10.3390/w11010127 ◽

2019 ◽

Vol 11 (1) ◽

pp. 127 ◽

Cited By ~ 2

Author(s):

João Gomes ◽

Danilo Frasson ◽

Rosa Quinta-Ferreira ◽

Ana Matos ◽

Rui Martins

Keyword(s):

Volcanic Rock ◽

Emerging Contaminants ◽

Municipal Wastewater ◽

Jc Virus ◽

Low Cost ◽

Catalytic Ozonation ◽

Enteric Pathogens ◽

Treated Wastewater ◽

Genotype I ◽

Treatment Technologies

Water scarcity is one of the main problems of this century. Water reclamation appears as an alternative due to the reuse of treated wastewater. Therefore, effluents treatment technologies (activated sludge, rotary biological discs, percolating beds) must be improved since they are not able to remove emerging contaminants such as enteric pathogens (bacteria and virus). These pollutants are difficult to remove from the wastewater and lead to adverse consequences to human health. Advanced oxidation processes, such as single and catalytic ozonation, appear as suitable complements to conventional processes. Catalytic ozonation was carried out using a low-cost material, a volcanic rock. Single and catalytic ozonation were capable of promoting total Escherichia coli removal from municipal wastewater after 90 min of contact. The presence of volcanic rock increases disinfection efficiency since E. coli regrowth was not observed. The identified viruses (Norovirus genotype I and II and JC virus) were completely removed using catalytic ozonation, whereas single ozonation was not able to eliminate JC virus even after 150 min of treatment. The higher performance of the catalytic process can be explained by the formation of hydroxyl radicals, proving that disinfection occurs in the liquid bulk and not due to adsorption at the volcanic rock.

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Analysis of eutrophication potential of municipal wastewater

Water Science & Technology ◽

10.2166/wst.2020.254 ◽

2020 ◽

Vol 81 (9) ◽

pp. 1994-2003

Author(s):

M. Preisner ◽

E. Neverova-Dziopak ◽

Z. Kowalewski

Keyword(s):

Wastewater Treatment ◽

Municipal Wastewater ◽

Wastewater Treatment Plants ◽

The United States ◽

Treated Wastewater ◽

Nutrient Loads ◽

Nitrogen And Phosphorus ◽

Eutrophication Potential ◽

Wastewater Quality ◽

Treatment Technologies

Abstract One of the main factors of the increased eutrophication level of surface waters is the high anthropogenic loads of biogenic substances discharged into water bodies. Municipal wastewaters, containing large amounts of nitrogen and phosphorus play one of the key roles in the acceleration of eutrophication intensity. The main direction in the prevention of eutrophication caused by wastewater discharge has become the reduction of nutrient loads introduced to wastewater receivers in accordance with strict legal requirements achievable only in advanced technologies. The treated wastewater quality standards are actually developed for total nitrogen and total phosphorus content, disregarding the fact that eutrophication potential of treated wastewater is determined by the content of non-organic nutrient forms directly bioavailable for water vegetation. That is why the currently used energy-consuming and expensive technologies do not always guarantee effective protection against eutrophication and its consequences. The goal of the study was to analyze the most widely used wastewater treatment technologies for enhanced biological nutrients removal in treated wastewater eutrophication potential. For this purpose, an analysis of the operation of 18 wastewater treatment plants based on different technologies in Finland, Canada, Poland, Russia and the United States was realized. The analysis concluded that the eutrophication potential of treated wastewater to a large extent is conditioned by the applied technology. The results of the research concluded that the eutrophication potential can serve an important criterion for decision-making regarding the proper selection of wastewater treatment technologies aimed at eutrophication mitigation.

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Costs of tertiary treatment of municipal wastewater by rapid sand filter with coagulants and UV

Water Science & Technology Water Supply ◽

10.2166/ws.2003.0056 ◽

2003 ◽

Vol 3 (4) ◽

pp. 145-152 ◽

Cited By ~ 3

Author(s):

H. Heinonen-Tanski ◽

P. Juntunen ◽

R. Rajala ◽

E. Haume ◽

A. Niemelä

Keyword(s):

Total Phosphorus ◽

Municipal Wastewater ◽

Pilot Scale ◽

Treated Wastewater ◽

Tertiary Treatment ◽

Sand Filter ◽

Physico Chemical ◽

Bathing Waters ◽

Filtration Unit ◽

Microbial Groups

Municipal treated wastewater has been tertiary treated in a pilot-scale rapid sand filter. The filtration process was improved by using polyaluminium coagulants. The sand-filtered water was further treated with one or two UV reactors. The quality changes of wastewater were measured with transmittance, total phosphorus, soluble phosphorus, and somatic coliphages, FRNA-coliphages, FC, enterococci and fecal clostridia. Sand filtration alone without coagulants improved slightly some physico-chemical parameters and it had almost no effect on content of microorganisms. If coagulants were used, the filtration was more effective. The reductions were 88-98% for microbial groups and 80% for total phosphorus. The wastewater would meet the requirements for bathing waters (2,000 FC/100 ml, EU, 1976). UV further improved the hygiene level; this type of treated wastewater could be used for unrestricted irrigation (2.2 TC/100 ml, US.EPA 1992). The improvement was better if coagulants were used. The price for tertiary treatment (filtration + UV) would have been 0.036 Euro/m3 according to prices in 2001 in 22 Mm3/a. The investment cost needed for the filtration unit was 0.020 Euro/m3 (6%/15a). Filtration with coagulants is recommended in spite of its costs, since the low transmittance of unfiltered wastewater impairs the efficiency of the UV treatment.

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Typology of Municipal Wastewater Treatment Technologies in Latin America

CLEAN - Soil Air Water ◽

10.1002/clen.201100707 ◽

2012 ◽

Vol 40 (9) ◽

pp. 926-932 ◽

Cited By ~ 43

Author(s):

Adalberto Noyola ◽

Alejandro Padilla-Rivera ◽

Juan Manuel Morgan-Sagastume ◽

Leonor Patricia Güereca ◽

Flor Hernández-Padilla

Keyword(s):

Wastewater Treatment ◽

Latin America ◽

Municipal Wastewater ◽

Municipal Wastewater Treatment ◽

Treatment Technologies

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Cultivation of rice for animal feed with circulated irrigation of treated municipal wastewater for enhanced nitrogen removal: comparison of cultivation systems feeding irrigation water upward and downward

Water Science & Technology ◽

10.2166/wst.2015.251 ◽

2015 ◽

Vol 72 (4) ◽

pp. 579-584 ◽

Cited By ~ 7

Author(s):

A. Muramatsu ◽

H. Ito ◽

A. Sasaki ◽

A. Kajihara ◽

T. Watanabe

Keyword(s):

Nitrogen Removal ◽

Irrigation Water ◽

Rice Plant ◽

Municipal Wastewater ◽

Animal Feed ◽

Paddy Fields ◽

Treated Wastewater ◽

Human Consumption ◽

Cultivation System ◽

Treated Municipal Wastewater

To achieve enhanced nitrogen removal, we modified a cultivation system with circulated irrigation of treated municipal wastewater by using rice for animal feed instead of human consumption. The performance of this modified system was evaluated through a bench-scale experiment by comparing the direction of circulated irrigation (i.e. passing through paddy soil upward and downward). The modified system achieved more than three times higher nitrogen removal (3.2 g) than the system in which rice for human consumption was cultivated. The removal efficiency was higher than 99.5%, regardless of the direction of circulated irrigation. Nitrogen in the treated municipal wastewater was adsorbed by the rice plant in this cultivation system as effectively as chemical fertilizer used in normal paddy fields. Circulated irrigation increased the nitrogen released to the atmosphere, probably due to enhanced denitrification. Neither the circulation of irrigation water nor its direction affected the growth of the rice plant and the yield and quality of harvested rice. The yield of rice harvested in this system did not reach the target value in normal paddy fields. To increase this yield, a larger amount of treated wastewater should be applied to the system, considering the significant amount of nitrogen released to the atmosphere.

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Novel biofilm reactor for denitrification of municipal wastewater

Water Science & Technology ◽

10.2166/wst.2018.433 ◽

2018 ◽

Vol 78 (7) ◽

pp. 1566-1575 ◽

Cited By ~ 3

Author(s):

S. S. Rathnaweera ◽

B. Rusten ◽

K. Korczyk ◽

B. Helland ◽

E. Rismyhr

Keyword(s):

Carbon Source ◽

Municipal Wastewater ◽

Low Cost ◽

Oxygen Demand ◽

Pilot Scale ◽

Biofilm Reactor ◽

Treated Wastewater ◽

Removal Rates ◽

Good Filter ◽

Solids Removal

Abstract A pilot-scale CFIC® (continuous flow intermittent cleaning) reactor was run in anoxic conditions to study denitrification of wastewater. The CFIC process has already proven its capabilities for biological oxygen demand removal with a small footprint, less energy consumption and low cost. The present study focused on the applicability for denitrification. Both pre-denitrification (pre-DN) and post-denitrification (post-DN) were tested. A mixture of primary treated wastewater and nitrified wastewater was used for pre-DN and nitrified wastewater with ethanol as a carbon source was used for post-DN. The pre-DN process was carbon limited and removal rates of only 0.16 to 0.74 g NOx-N/m²-d were obtained. With post-DN and an external carbon source, 0.68 to 2.2 g NO3-Neq/m²-d removal rates were obtained. The carrier bed functioned as a good filter for both the larger particles coming with influent water and the bio-solids produced in the reactor. Total suspended solids removal in the reactor varied from 20% to 78% (average 45%) during post-DN testing period and 9% to 70% (average 29%) for pre-DN. The results showed that the forward flow washing improves both the DN function and filtration ability of the reactor.

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TESTING OF CHLORELLA/SCENEDESMUS MICROALGAE CONSORTIA FOR REMEDIATION OF WASTEWATER, CO₂ MITIGATION AND ALGAE BIOMASS FEASIBILITY FOR LIPID PRODUCTION

Journal of Environmental Engineering and Landscape Management ◽

10.3846/16486897.2013.911182 ◽

2014 ◽

Vol 22 (2) ◽

pp. 105-114 ◽

Cited By ~ 27

Author(s):

Judita Koreivienė ◽

Robertas Valčiukas ◽

Jūratė Karosienė ◽

Pranas Baltrėnas

Keyword(s):

Municipal Wastewater ◽

Global Climate ◽

Inorganic Nitrogen ◽

Lipid Production ◽

Single Species ◽

Inorganic Phosphorus ◽

Climatic Conditions ◽

Biofuel Production ◽

Treated Wastewater ◽

Algae Biomass

Industry, transport and unsustainable agriculture result in the increased quantity of wastewater, release of nutrients and emission of carbon dioxide that promotes eutrophication of water bodies and global climate change. the application of microalgae for phycoremediation, their biomass use for human needs may increase sustainability and have a positive effect on the regional development. The experiments were carried out in order to establish the feasibility of treating the local municipal wastewater with microalgae consortia and their biomass potential for biofuel production. The results revealed that Chlorella/Scenedesmus consortium eliminated up to 99.7–99.9% of inorganic phosphorus and up to 88.6–96.4% of inorganic nitrogen from the wastewater within three weeks. The ammonium removal was more efficient than that of nitrate. Chlorella algae grew better in diluted, while Scenedesmus – in the concentrated wastewater. The consortium treated wastewater more efficiently than a single species. The maximum biomass (3.04 g/L) of algal consortium was estimated in concentrated wastewater. Algae accumulated 0.65–1.37 g of CO2/L per day in their biomass. Tus, Chlorella/Scenedesmus consortium is a promising tool for nutrients elimination from the local wastewater under the climatic conditions specific to Lithuania. However, none of the two species were able to accumulate lipids under the nitrogen starvation conditions.

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The effect of sub-irrigation with untreated and treated municipal wastewater on organic matter and Nitrogen content on two soil types

Global NEST Journal ◽

10.30955/gnj.002810 ◽

2019 ◽

Keyword(s):

Organic Matter ◽

Nitrogen Content ◽

Total Nitrogen ◽

Municipal Wastewater ◽

Tap Water ◽

Soil Mass ◽

Treated Wastewater ◽

Total N ◽

Untreated Wastewater ◽

Zone Ii

<p>In order to study the chemical parameters of the soil after sub-irrigation with wastewater, a system was installed in one of the greenhouses of the Agricultural University of Athens. Wastewater was applied subsurface into the soil mass of the pots were used. Three treatments were used: Untreated wastewater (U), Treated wastewater (T) and tap water (W) as control. Two different types were used: Soil (a) characterized as Sandy loam and soil (b) characterized as Loamy sand. Moreover, in order to investigate the change of total Nitrogen and organic matter concentrations at the point where the emitter was placed, the soil mass was divided into two zones. The upper (zone I) and the lower one (zone II). The total nitrogen content, ammonia nitrogen (NH4-N), nitrogen nitrate (NO3-N) and the percentage of organic matter, were determined in the soil samples. Statistically significant differences (p <0, 05) were observed in the organic matter and the total N%, only for soil (b). For soil (a), organic matter percentage was increased in zone (I) (irrigation with treated wastewater at 20 cm depth). For soil (b), total N% was increased in zone (I), while nitrate and ammonium were increased in zone (II) (irrigation with untreated wastewater at 20 cm depth).</p>

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Efficiency of municipal wastewater treatment with membrane bioreactor

Journal of Water and Land Development ◽

10.2478/jwld-2019-0026 ◽

2019 ◽

Vol 41 (1) ◽

pp. 47-54

Author(s):

Magdalena Domańska ◽

Anna Boral ◽

Kamila Hamal ◽

Magdalena Kuśnierz ◽

Janusz Łomotowski ◽

...

Keyword(s):

Wastewater Treatment ◽

Membrane Filtration ◽

Municipal Wastewater ◽

High Efficiency ◽

Biological Membrane ◽

Treatment Plant ◽

Membrane Reactors ◽

Quality Analysis ◽

Treated Wastewater ◽

Municipal Wastewater Treatment

AbstractThe increasingly stringent requirements for wastewater treatment enforce the adoption of technologies that reduce pollution and minimize waste production. By combining the typical activated sludge process with membrane filtration, biological membrane reactors (MBR) offer great technological potential in this respect. The paper presents the principles and effectiveness of using an MBR at the Głogów Małopolski operation. Physicochemical tests of raw and treated wastewater as well as microscopic analyses with the use of the FISH (fluorescence in situ hybridization) method were carried out. Moreover, the level of electric energy consumption during the operation of the wastewater treatment plant and problems related to fouling were also discussed. A wastewater quality analysis confirmed the high efficiency of removing organic impurities (on average 96% in case of BOD5 and 94% in case of COD) and suspension (on average 93%).

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Comparative Study on Micronsized and Nanosized Carica papaya Seed Modified Pullulan as Biocoagulant in Wastewater Treatment

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.317.276 ◽

2021 ◽

Vol 317 ◽

pp. 276-282

Author(s):

Deong Jing Lie ◽

Mazatusziha Ahmad ◽

Nur Sabrina Azhar

Keyword(s):

Particle Size ◽

Wastewater Treatment ◽

Carica Papaya ◽

Municipal Wastewater ◽

Particle Interaction ◽

Test Method ◽

Treated Wastewater ◽

Limited Information ◽

Natural Polymers ◽

Jar Test

Plant-based coagulants have been used as an alternative material to replace chemical coagulant in wastewater treatment. So far, limited information was found on the incorporation of plant-based biocoagulant to natural polymers and the effect of particle size upon wastewater treatment application. Thus, this study was conducted to explore the effectiveness of micronsized and nanosized Carica Papaya (CP) seed modified pullulan as biocoagulant. Biocoagulant were prepared at different composition of CP to pullulan, with the CP content range from 1% to 9%. The biocoagulant were characterized via Particle Size Analyzer (PSA), Fourier Transform Infrared Spectroscopy (FTIR) and morphological analysis via Field Emission Scanning Electron Microscopy (FESEM). It was used to treat municipal wastewater. The treated wastewater quality was analyzed by jar test method with dosage of biocoagulant used was 0.6g/L. Result showed that the 10% (D10), 50% (D50) and 90% (D90) distribution of micronsized CP had particle size of 0.3675 µm, 0.8433 µm and 1.9537 µm respectively. The nanosized CP was 0.4473nm (D10), 2.3758nm (D50) and 2.9938nm (D90). Characterization of biocoagulant via FTIR revealed the appearance of O-H, C=O, C-H and C-O-C bond which contribute to particle interaction for turbidity reduction of wastewater. Jar test analysis found that at 3% micronsized CP and 7% nanosized CP were able to reduce turbidity up to 59.65% and 65.27% respectively. Both size of biocoagulant slightly changed the pH of treated wastewater to neutral, increased in dissolved oxygen (DO) and reduced in total suspended solid (TSS). Overall, nanosized CP was found more effective as compared to micronsized CP.

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