Sewage pre-concentration for maximum recovery and reuse at decentralized level

2013 ◽  
Vol 67 (6) ◽  
pp. 1188-1193 ◽  
Author(s):  
V. Diamantis ◽  
W. Verstraete ◽  
A. Eftaxias ◽  
B. Bundervoet ◽  
V. Siegfried ◽  
...  
Keyword(s):  
Water Reuse ◽  
Membrane Filtration ◽  
Municipal Wastewater ◽  
Oxygen Demand ◽  
Primary Treatment ◽  
Small Scale ◽  
Biogas Yield ◽  
Anaerobic Reactors ◽  
Dead End ◽  
Chemically Enhanced Primary Treatment

Pre-concentration of municipal wastewater by chemically enhanced primary treatment (CEPT) was studied under controlled laboratory conditions. Both iron and aluminium-based coagulants were examined at gradually increasing concentrations (0.23, 0.35, 0.70 and 1.05 mmol/L). The CEPT sludge generated from different coagulation experiments was digested in batch anaerobic reactors, while the supernatant was tested in a dead-end microfiltration setup. The results of the study show that biogas yield was dramatically decreased (from 0.40 to 0.10 m3/kg chemical oxygen demand of influent) with increasing coagulant dose. In contrast, supernatant filterability was improved. Based on the laboratory results, a conceptual design was produced for a community of 2000 inhabitant equivalents (IE), using CEPT technology (at low coagulant dose) with anaerobic digestion of the concentrates. According to this, the capital and operational costs were 0.11 and 0.09 €/m3, respectively. The biogas generated is used for digester heating and the overall process is energy self-sufficient. At a small-scale and in private applications, CEPT technology is preferably operated at higher coagulant dose, followed by membrane filtration for water reuse. Accordingly, sewage purification and reuse is possible without implementing aerobic biological processes.

scholarly journals Rotating belt sieves for primary treatment, chemically enhanced primary treatment and secondary solids separation

2017 ◽  
Vol 75 (11) ◽  
pp. 2598-2606 ◽  
Author(s):  
B. Rusten ◽  
S. S. Rathnaweera ◽  
E. Rismyhr ◽  
A. K. Sahu ◽  
J. Ntiako
Keyword(s):  
Removal Efficiency ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Primary Treatment ◽  
Biofilm Reactors ◽  
Fine Mesh ◽  
Coagulation And Flocculation ◽  
Successful Removal ◽  
Solids Separation ◽  
Chemically Enhanced Primary Treatment

Fine mesh rotating belt sieves (RBS) offer a very compact solution for removal of particles from wastewater. This paper shows examples from pilot-scale testing of primary treatment, chemically enhanced primary treatment (CEPT) and secondary solids separation of biofilm solids from moving bed biofilm reactors (MBBRs). Primary treatment using a 350 microns belt showed more than 40% removal of total suspended solids (TSS) and 30% removal of chemical oxygen demand (COD) at sieve rates as high as 160 m³/m²-h. Maximum sieve rate tested was 288 m³/m²-h and maximum particle load was 80 kg TSS/m²-h. When the filter mat on the belt increased from 10 to 55 g TSS/m², the removal efficiency for TSS increased from about 35 to 60%. CEPT is a simple and effective way of increasing the removal efficiency of RBS. Adding about 1 mg/L of cationic polymer and about 2 min of flocculation time, the removal of TSS typically increased from 40–50% without polymer to 60–70% with polymer. Using coagulation and flocculation ahead of the RBS, separation of biofilm solids was successful. Removal efficiencies of 90% TSS, 83% total P and 84% total COD were achieved with a 90 microns belt at a sieve rate of 41 m³/m²-h.

Effect of selective organic fractions on denitrification rates using Salsnes Filter as primary treatment

2014 ◽  
Vol 69 (9) ◽  
pp. 1942-1948 ◽  
Author(s):  
V. A. Razafimanantsoa ◽  
L. Ydstebø ◽  
T. Bilstad ◽  
A. K. Sahu ◽  
B. Rusten
Keyword(s):  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Oxygen Demand ◽  
Primary Treatment ◽  
Biofilm Reactor ◽  
Biological Nutrient Removal ◽  
Particle Removal ◽  
Fine Mesh ◽  
Organic Fractions ◽  
Removal Processes

The purpose of this project was to investigate the effect of selective particle removal during primary treatment on downstream biological nutrient removal processes. Bench-scale Salsnes Filter fine mesh sieves were used as a primary treatment to obtain different organic fractions to test the effect on denitrification. Activated sludge and moving bed biofilm reactor anoxic tests were performed on municipal wastewater collected from two full-scale wastewater treatment plants located around the Oslo region (Norway). About 43% of the suspended solids in the wastewater was less than 18 μm, and 14% was between 18 and 150 μm. The effect of particulate chemical oxygen demand (COD) removal on denitrification rates was very minor.

scholarly journals Impact assessment of water and nutrient reuse in hydroponic systems using Bayesian Belief Networks

2020 ◽  
Vol 10 (4) ◽  
pp. 431-442 ◽  
Author(s):  
Martin Zimmermann ◽  
Michaela Fischer
Keyword(s):  
Water Reuse ◽  
Crop Production ◽  
Municipal Wastewater ◽  
Expert Knowledge ◽  
Research Question ◽  
Agricultural Practices ◽  
Bayesian Belief Networks ◽  
Ecological Impacts ◽  
Small Scale ◽  
Hydroponic Systems

Abstract Water-saving agricultural practices can reduce negative environmental impacts in water-scarce regions all over the world. This study deals with an innovation that combines hydroponic crop production and municipal wastewater reuse for irrigation purposes. The research question was what impacts such hydroponic water reuse systems have on product confidence, economic viability, groundwater recharge, biodiversity and landscape quality. It should also be clarified under which conditions and with which measures these systems can be sustainable. To answer these questions, a number of generic hydroponic water reuse systems were modeled and assessed using a Bayesian Belief Network that included both numerical values and expert knowledge. The hydroponic water reuse systems with the most positive overall impacts are small-scale food production systems (tomatoes) equipped with lighting and heating whose products are marked with a quality label or with a label for regional products. The systems are located in a former industrial area. In addition, a wetland system and landscape integration are implemented as landscaping measures. Hydroponic systems can be operated economically viable, their products have a high level of product confidence and their ecological impacts can be positive. No tradeoffs have to be accepted between economic, social and ecological goals.

scholarly journals Obtaining filamentous fungi and lipases from sewage treatment plant residue for fat degradation in anaerobic reactors

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5368 ◽  
Author(s):  
Anna Cristina P. Lima ◽  
Magali C. Cammarota ◽  
Melissa L.E. Gutarra
Keyword(s):  
Filamentous Fungi ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Basal Medium ◽  
Primary Treatment ◽  
Lipase Production ◽  
Plant Residue ◽  
Anaerobic Reactors

A residue from the primary treatment of a Wastewater Treatment Plant (WWTP) was used to isolate filamentous fungi with lipase production potential. Two of the 27 isolated fungi presented high hydrolysis index and were selected for lipase production by solid-state fermentation (SSF). The fermentations were conducted at 30 °C for 48 h, with moist air circulation, using 20% (w/w) of the residue mixture with a basal medium (agroindustrial residue—babassu cake), obtaining a solid enzymatic preparation (SEP) with lipase activity of 19 U/g with the fungus identified as Aspergillus terreus. Scum, collected in an anaerobic reactor operating in a WWTP, was hydrolyzed with SEP and subjected to anaerobic biodegradability tests at 30 °C. Different dilutions of crude (Control) or hydrolyzed scum in raw sewage were evaluated. The dilution of 5% (v/v) of hydrolyzed scum in raw sewage proved the most adequate, as it resulted in higher methane yield compared to the raw sewage (196 and 133 mL CH4/g CODadded, respectively), without increasing the chemical oxygen demand (COD) of the treated sewage (138 and 134 mg/L). The enzymatic hydrolysis of the scum, followed by dilution in the influent sewage, is technically feasible and increases methane production in anaerobic reactors.

Chemically enhanced primary treatment of municipal wastewater with ferrate(VI)

2020 ◽  
Author(s):  
Lei Zheng ◽  
Huan Feng ◽  
Yueqiang Liu ◽  
Jinshan Gao ◽  
Dibyendu Sarkar ◽  
...  
Keyword(s):  
Municipal Wastewater ◽  
Primary Treatment ◽  
Chemically Enhanced Primary Treatment

Microfiltration of municipal wastewater for disinfection and advanced phosphorus removal

1996 ◽  
Vol 34 (9) ◽  
pp. 125-131 ◽  
Author(s):  
J. Dittrich ◽  
R. Gnirss ◽  
A. Peter-Fröhlich ◽  
F. Sarfert
Keyword(s):  
Wastewater Treatment ◽  
Energy Consumption ◽  
Phosphorus Removal ◽  
Municipal Wastewater ◽  
Cross Flow ◽  
Full Scale ◽  
Small Scale ◽  
Research Project ◽  
Dead End ◽  
Final Effluent

The objective of Research Project 02 WA 9253/4 on “Advanced Treatment of Municipal Wastewater: Microfiltration of municipal wastewater for disinfection and advanced phosphorus removal” which is supported by the BMBF (Federal Ministry for Education, Science, Research and Technology) is to show whether microfiltration (MF) is a technically feasible and economically competitive process for disinfection and phosphorus removal of secondary effluent. For bacteria and phosphorus removal, three different microfiltration systems (systems with flat sheet, tube and hollow-fibre modules) with a pore size of 0.2 μm are tested in small-scale pilot plants to find out whether they are suitable for municipal wastewater treatment. The most suitable system will afterwards be tested in one full-scale unit to obtain operational data. The monitoring program with the small-scale MF plants using the final effluent of the Berlin-Ruhleben wastewater treatment plant started in November 1993 and the results obtained so far can be summarized as follows. Total coliforms, E. coli, faecal streptococci and salmonella are removed to levels below the detection limit, less than 1 cfu/100 ml in the effluent of all three MF plants. Coliphage - as a surrogate organism for enterovirus - are significantly reduced with a 2-3 log removal, which means that the limit value for enterovirus laid down in the EU Bathing Water Directive can be met in the effluent of the MF plants. The average concentrations for total phosphorus (PT) in the effluent are 60 μg/l for the Memcor and the DOW units and 90 μg/l for the Starcosa unit without the use of precipitants. With a low ferric dosage of 0.014 mol/m3 prior to the MF, the average effluent PT concentrations of all three MF units are lower than the target concentration of 50 μg/l (no polymer feed). With a specific energy consumption of about 0.2 kWh/m3 filtrate the dead-end MF (Memcor) requires at least five times less energy than the cross-flow MF. Based on the energy consumption dead-end MF should be preferred if large volumetric flows of wastewater with a low concentration of solids have to be treated. Because of unfavourable energy consumption the tests with the cross-flow MF have been discontinued. When using MF systems in the final effluent of wastewater treatment plants, evidence must be produced in a full-scale MF unit to demonstrate that microfiltration is really suitable for practical application. This as well as a reliable calculation of investment and operating costs are the main objectives of further investigations within the framework of this research project.

Microsieving in primary treatment: effect of chemical dosing

2016 ◽  
Vol 74 (2) ◽  
pp. 438-447 ◽  
Author(s):  
J. Väänänen ◽  
M. Cimbritz ◽  
J. la Cour Jansen
Keyword(s):  
Wastewater Treatment ◽  
Phosphorus Removal ◽  
Suspended Solids ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Pilot Scale ◽  
Primary Treatment ◽  
Municipal Wastewater Treatment ◽  
Chemically Enhanced Primary Treatment ◽  
Municipal Wastewater Treatment Plants

Primary and chemically enhanced primary wastewater treatment with microsieving (disc or drum filtration) was studied at the large pilot scale at seven municipal wastewater treatment plants in Europe. Without chemical dosing, the reduction of suspended solids (SS) was (on average) 50% (20–65%). By introducing chemically enhanced primary treatment and dosing with cationic polymer only, SS removal could be controlled and increased to >80%. A maximum SS removal of >90% was achieved with a chemical dosing of >0.007 mg polymer/mg influent SS and 20 mg Al3+/L or 30 mg Fe3+/L. When comparing sieve pore sizes of 30–40 μm with 100 μm, the effluent SS was comparable, indicating that the larger sieve pore size could be used due to the higher loading capacity for the solids. Phosphorus removal was adjusted with the coagulant dose, and a removal of 95–97% was achieved. Moreover, microsieving offers favourable conditions for automated dosing control due to the low retention time in the filter.

Combination of microalgae cultivation with membrane processes for the treatment of municipal wastewater

2013 ◽  
Vol 68 (11) ◽  
pp. 2374-2381 ◽  
Author(s):  
Lu Chen ◽  
Jiang Wei ◽  
Weiguo Wang ◽  
Cunwen Wang
Keyword(s):  
Chemical Oxygen Demand ◽  
Membrane Filtration ◽  
Municipal Wastewater ◽  
Oxygen Demand ◽  
Permeate Flux ◽  
Microalgae Cultivation ◽  
New Approach ◽  
Critical Issues ◽  
Uf Membranes ◽  
Residual Solution

The treatment of wastewater by microalgae cultivation has attracted more and more attention. However, the way to harvest microalgae cells from the wastewater and the treatment of the large quantity of residual solution have become critical issues. In this work, a new approach for the treatment of municipal wastewater is presented. The combination of flocculation for removing mainly microalgae and thereafter membrane filtration for chemical oxygen demand (COD) and conductivity reduction of the residual solution after flocculation is discussed. The COD concentration of the wastewater decreased from 260 to 84 mg/L after flocculation by chitosan. Five ultrafiltration (UF) membranes and two nanofiltration (NF) membranes were used for filtration to find a suitable membrane for COD and conductivity reduction. Among the five UF membranes, GR82PE showed the best performance, whose permeate flux and COD retention at 4 bar were 189.66 L/(m2·h) and 43.03%, respectively. NF membranes showed higher COD and conductivity retentions than UF membranes. The COD retention of Desal5-DK reached 98.3% at 20 bar. Lastly, the flux recovery after the filtration test of each membrane is also discussed.

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