scholarly journals Gravity-Driven Membrane Reactor for Decentralized Wastewater Treatment: Effect of Reactor Configuration and Cleaning Protocol

Membranes ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 388
Author(s):  
Ihtisham Ul Haq Shami ◽  
Bing Wu
Keyword(s):  
Wastewater Treatment ◽  
Municipal Wastewater ◽  
Economic Feasibility ◽  
Reactor Configuration ◽  
Membrane Performance ◽  
Decentralized Wastewater Treatment ◽  
Water Head ◽  
Cake Layer ◽  
Gravity Driven ◽  
Cleaning Protocol

In this study, three gravity-driven membrane (GDM) reactors with flat sheet membrane modules and various biocarriers (synthetic fibers, lava stones, and sands) were operated for municipal wastewater treatment. The effects of water head, periodically cleaning protocol, and operation temperature on the GDM reactor performance were illustrated in terms of membrane performance and water quality. The results indicated that: (1) the cake layer fouling was predominant (>~85%), regardless of reactor configuration and operation conditions; (2) under lower water head, variable water head benefited in achieving higher permeate fluxes due to effective relaxation of the compacted cake layers; (3) the short-term chemical cleaning (30–60 min per 3–4 days) improved membrane performance, especially when additional physical shear force was implemented; (4) the lower temperature had negligible effect on the GDM reactors packed with Icelandic lava stones and sands. Furthermore, the wastewater treatment costs of the three GDM reactors were estimated, ranging between 0.31 and 0.37 EUR/m3, which was greatly lower than that of conventional membrane bioreactors under lower population scenarios. This sheds light on the technical and economic feasibility of biocarrier-facilitated GDM systems for decentralized wastewater treatment in Iceland.

A pilot scale study of a sequencing batch reactor treating municipal wastewater operated via the UP-PND process

2008 ◽  
Vol 58 (2) ◽  
pp. 435-438 ◽  
Author(s):  
M. Kornaros ◽  
C. Marazioti ◽  
G. Lyberatos
Keyword(s):  
Wastewater Treatment ◽  
Municipal Wastewater ◽  
Batch Reactor ◽  
Treatment Plant ◽  
Pilot Scale ◽  
Treated Wastewater ◽  
Synthetic Wastewater ◽  
Second Step ◽  
Decentralized Wastewater Treatment ◽  
Real Wastewater

SBRs are usually preferred as small and decentralized wastewater treatment systems. We have demonstrated previously that using a frequent enough switching between aerobic and anoxic conditions and a specific to the treated wastewater aerobic to anoxic phase ratio, it is possible to by-pass the second step of nitrification (i.e. conversion of nitrite to nitrate nitrogen). This innovative process for nitrate by-pass has been branded as UP-PND (University of Patras-Partial Nitrification Denitrification) (WO 2006/129132). The proved methodology was successfully transferred from a lab-scale SBR reactor treating synthetic wastewater to a pilot-scale SBR system treating real wastewater. In this work we present the results from the operation of this pilot-scale SBR, constructed in the Wastewater Treatment Plant of Patras (Greece), using 6-hour, 8-hour and 12-hour cycles. It is demonstrated that three pairs of aerobic/anoxic phases with a relative duration of 1:2 (8-hour cycle) and 2:3 (12-hour cycle) secures the desired by-pass of nitrate production.

scholarly journals Cost of Urban Wastewater Treatment and Ecotaxes: Evidence from Municipalities in Southern Europe

Water ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 423 ◽  
Author(s):  
Encarnación Moral Pajares ◽  
Leticia Gallego Valero ◽  
Isabel Román Sánchez
Keyword(s):  
Wastewater Treatment ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Methodological Approach ◽  
Economic Feasibility ◽  
Wastewater Management ◽  
Management Service ◽  
Southern Europe ◽  
Urban Wastewater ◽  
Urban Wastewater Treatment

The principle of cost recovery established by the Water Framework Directive underlines the need for tax rates, which can raise enough revenue to finance the cost of treatments applied to wastewater. The objective of this research is to gain an understanding the different types of charges related to urban wastewater treatment that can be levied by the authorities responsible for this service. This paper also aims to determine whether these taxes contribute to guaranteeing the economic feasibility of the wastewater treatment plants. The proposed methodological approach is applied to 18 municipalities of a province in southern Europe in 2017. The results confirm that in most of these cases, the taxes levied do not guarantee adequate tax revenues to cover the running, maintenance and investment costs of municipal wastewater treatment plants. This situation leads to a lack of financial self-sufficiency in the wastewater management service, meaning that the imbalance between income and expenditure has to be covered by government subsidies. The results of this study will help guide authorities around the world that are in charge of managing urban wastewater treatment services.

Modelling and simulation of filtration performance in membrane bioreactor systems for municipal wastewater treatment

2003 ◽  
Vol 3 (5-6) ◽  
pp. 267-273 ◽  
Author(s):  
T. Wintgens ◽  
J. Rosen ◽  
T. Melin ◽  
C. Brepols ◽  
K. Drensla ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Membrane Bioreactor ◽  
Municipal Wastewater ◽  
Treatment Plant ◽  
Transfer Model ◽  
Municipal Wastewater Treatment ◽  
Permeability Evolution ◽  
Filtration Performance ◽  
Cake Layer ◽  
Filtration Unit

The paper outlines a model of the filtration performance of submerged capillary microfiltration modules in membrane bioreactor applications for wastewater treatment. The model was implemented for process simulation and calibrated by using operating data of the full-scale municipal wastewater treatment plant Rödingen, Germany, operated by Erft River Association (Erftverband), which is equipped with activated sludge treatment and microfiltration units for biomass retention. Mathematically recordable foundations of filtration resistances, such as cake layer forming and fouling, are presented along with a mass transfer model, describing the concentration polarisation on the feed-side and its dependence on a multiphase flow regime. The model simulates the long-term decrease in permeability of the membranes and outlines the influence of main operating parameters on flux performance. After parameter fitting for one filtration unit, the permeability evolution for a second unit could be also calculated.

scholarly journals Cleaning optimisation of reverse osmosis membranes used for wastewater reclamation

2012 ◽  
Vol 2 (1) ◽  
pp. 47-54
Author(s):  
X. Bernat ◽  
G. Prats ◽  
O. Gibert ◽  
B. Lefèvre ◽  
J. Tobella
Keyword(s):  
Reverse Osmosis ◽  
Municipal Wastewater ◽  
Economic Feasibility ◽  
Low Molecular Weight ◽  
Wastewater Reclamation ◽  
Tertiary Treatment ◽  
Cleaning Efficiency ◽  
Membrane Cleaning ◽  
The Impact ◽  
Cleaning Protocol

Wastewater reclamation contributes to the preservation of conventional water resources and thus helps to ensure appropriate human development for future generations. Wastewater reclamation can be achieved through several technologies. One of the most common technologies is the tertiary treatment of urban municipal wastewater, which is often based on membrane technologies. Reverse osmosis is an effective separation technology for removing dissolved salts and low molecular weight organic compounds. However, membranes suffer from fouling, which directly reduces technical, environmental and economic feasibility of the process and hence of the reclamation plant. One of the strategies helpful to reduce fouling is the optimisation of the membranes’ cleaning and maintenance. The aim of this work is to test the impact of the membrane cleaning protocol design on the recovery of the original properties of a reverse osmosis membrane used for several years in a wastewater reclamation plant in Spain. Furthermore, the work is focused on the validation of the adequacy of the most-common indicators used for assessing membranes’ cleaning efficiency.

scholarly journals Polyhydroxyalkanoates (PHAs) Production: A Feasible Economic Option for the Treatment of Sewage Sludge in Municipal Wastewater Treatment Plants?

Water ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 1118 ◽  
Author(s):  
Dafne Crutchik ◽  
Oscar Franchi ◽  
Luis Caminos ◽  
David Jeison ◽  
Marisol Belmonte ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Value Added ◽  
Economic Feasibility ◽  
Production Costs ◽  
Anaerobic Sludge ◽  
Municipal Wastewater Treatment ◽  
Capital Costs ◽  
Municipal Wastewater Treatment Plants

Sludge is a by-product of municipal wastewater treatment plants (WWTPs) and its management contributes significantly to the operating costs. Large WWTPs usually have anaerobic sludge digesters to valorize sludge as methane and to reduce its mass. However, the low methane market price opens the possibility for generating other high value-added products from the organic matter in sludge, such as polyhydroxyalkanoates (PHAs). In this work, the economic feasibility of retrofitting two types of WWTPs to convert them into biofactories of crude PHAs was studied. Two cases were analyzed: (a) a large WWTP with anaerobic sludge digestion; and (b) a small WWTP where sludge is only dewatered. In a two-stage PHA-production system (biomass enrichment plus PHAs accumulation), the minimum PHAs cost would be 1.26 and 2.26 US$/kg PHA-crude for the large and small WWTPs, respectively. In a single-stage process, where a fraction of the secondary sludge (25%) is directly used to accumulate PHAs, the production costs would decrease by around 15.9% (small WWTPs) and 19.0% (large WWTPs), since capital costs associated with bioreactors decrease. Sensitivity analysis showed that the PHA/COD (Chemical Oxygen Demand) yield is the most crucial parameter affecting the production costs. The energy, methane, and sludge management prices also have an essential effect on the production costs, and their effect depends on the WWTP’s size.

Operation of a submerged aerobic membrane bioreactor for decentralised municipal wastewater treatment in North Africa

2012 ◽  
Vol 7 (3) ◽  
Author(s):  
George Skouteris ◽  
Tom C. Arnot ◽  
Firas Feki ◽  
Mouna Jraou ◽  
Sami Sayadi
Keyword(s):  
Wastewater Treatment ◽  
North Africa ◽  
Membrane Bioreactor ◽  
Municipal Wastewater ◽  
Domestic Wastewater ◽  
Permeate Flux ◽  
Mixed Liquor ◽  
Membrane Performance ◽  
Energy Benchmarking ◽  
Crop Irrigation

A pilot-scale aerobic membrane bioreactor (MBR) was operated for 6.5 months, alongside a full-sized conventional activated sludge (AS) plant, treating high-strength domestic wastewater originating from Sfax in Tunisia. The main target was to investigate whether or not the MBR could produce effluent suitable for unrestricted crop irrigation in Tunisia, a target that the AS plant fails to achieve. Membrane performance analysis and energy benchmarking were also carried out. The MBR did produce irrigation quality water regardless of the mixed-liquor suspended solids (MLSS) or feed concentrations. The average chemical oxygen demand (COD) removal efficiency was 88% at an average MLSS concentration of 4.59 g L−1, and 89.7% at an average MLSS concentration of 9.52 g L−1. During membrane performance evaluation, a maximum sustainable membrane permeate flux of 12.81 L m−2 h−1, at an average mixed-liquor temperature of 24 °C and an average MLSS concentration of 9.21 g L−1 was maintained. Finally, energy benchmarking was carried out; the average energy consumption rate was 8.95 kWh d−1, corresponding to an average specific energy demand (SED) of 3.82 kWh m−3. This is a relatively high value compared to the AS plant, whose SED value is always lower than 3 kWh m−3, but further energy reduction is possible for the MBR as well as the AS plant effluent requires further treatment in order to be acceptable for unrestricted human crop irrigation; hence, additional energy input. The work demonstrates the potential impact of MBRs in decentralised domestic wastewater treatment in North Africa.

scholarly journals Effectiveness and Energy Requirements of Pasteurisation for the Treatment of Unfiltered Secondary Effluent from a Municipal Wastewater Treatment Plant

Water ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2100
Author(s):  
Peter Sanciolo ◽  
Paul Monis ◽  
Justin Lewis ◽  
Greg Ryan ◽  
Andrew Salveson ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Heat Exchangers ◽  
Municipal Wastewater ◽  
Waste Heat ◽  
Treatment Plant ◽  
Economic Feasibility ◽  
Secondary Effluent ◽  
Heat Sensitivity ◽  
Municipal Wastewater Treatment ◽  
Treated Effluent

Pasteurisation was investigated as a process to achieve high microbial quality standards in the recycling of water from unfiltered secondary effluents from a wastewater treatment plants in Melbourne, Australia. The relative heat sensitivity of key bacterial, viral, protozoan and helminth wastewater organisms (Escherichia coli, Enterococcus, FRNA bacteriophage, adenovirus, coxsackievirus, Cryptosporidium, and Ascaris) were determined by laboratory scale tests. The FRNA phage were found to be the most heat resistant, followed by enterococci and E. coli. Pilot scale challenge testing of a 2 ML/day pasteurisation pilot plant using unfiltered municipal wastewater and male specific coliphage (MS2) phage showed that temperatures between 69 °C and 75 °C achieved log reductions values between 0.9 ± 0.1 and 5.0 ± 0.5 respectively in the contact chamber. Fouling of the heat exchangers during operation using unfiltered secondary treated effluent was found to increase the energy consumption of the plant from 2.2 kWh/kL to 5.1 kWh/kL. The economic feasibility of pasteurisation for the current municipal application with high heat exchanger fouling potential can be expected to depend largely on the available waste heat from co-generation and on the efforts required to control fouling of the heat exchangers.

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