Hybrid UF/NF process treating secondary effluent of wastewater treatment plants for potable water reuse: Adsorption vs. coagulation for removal improvements and membrane fouling alleviation

Rainfall diminution in the last years has entailed water scarcity in plenty of European regions, especially in Mediterranean areas. As a consequence, regional water authorities have enhanced wastewater reclamation and reuse. Thus, the implementation of tertiary treatments has become of paramount importance in the municipal wastewater treatment plants (WWTP) of Valencian Region (Spain). Conventional tertiary treatments consist of a physico-chemical treatment of the secondary effluent followed by sand filtration and UV radiation. However, the addition of coagulants and flocculants sometimes does not contribute significantly in the final water quality. In this work, results of 20-months operation of three WWTP in Valencian Region with different tertiary treatments (two without chemicals addition and another with chemicals addition) are discussed. Besides, experiments with a 2 m3/h pilot plant located in the WWTP Quart-Benager in Valencia were performed in order to evaluate with the same secondary effluent the effect of the chemicals addition on the final water quality. Results showed that the addition of chemicals did not improve the final water quality significantly. These results were observed both comparing the three full scale plants and in the pilot plant operation.

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Occurrence of SARS-CoV-2 RNA in Six Municipal Wastewater Treatment Plants at the Early Stage of COVID-19 Pandemic in The United States

Pathogens ◽

10.3390/pathogens10070798 ◽

2021 ◽

Vol 10 (7) ◽

pp. 798

Author(s):

Samendra P. Sherchan ◽

Shalina Shahin ◽

Jeenal Patel ◽

Lauren M. Ward ◽

Sarmila Tandukar ◽

...

Keyword(s):

United States ◽

Wastewater Treatment ◽

Municipal Wastewater ◽

Wastewater Treatment Plants ◽

Quantitative Polymerase Chain Reaction ◽

The United States ◽

Secondary Effluent ◽

Untreated Wastewater ◽

Treatment Processes ◽

Wastewater Samples

In this study, we investigated the occurrence of Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) RNA in primary influent (n = 42), secondary effluent (n = 24) and tertiary treated effluent (n = 34) collected from six wastewater treatment plants (WWTPs A–F) in Virginia (WWTP A), Florida (WWTPs B, C, and D), and Georgia (WWTPs E and F) in the United States during April–July 2020. Of the 100 wastewater samples analyzed, eight (19%) untreated wastewater samples collected from the primary influents contained SARS-CoV-2 RNA as measured by reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) assays. SARS-CoV-2 RNA were detected in influent wastewater samples collected from WWTP A (Virginia), WWTPs E and F (Georgia) and WWTP D (Florida). Secondary and tertiary effluent samples were not positive for SARS-CoV-2 RNA indicating the treatment processes in these WWTPs potentially removed SARS-CoV-2 RNA during the secondary and tertiary treatment processes. However, further studies are needed to understand the log removal values (LRVs) and transmission risks of SARS-CoV-2 RNA through analyzing wastewater samples from a wider range of WWTPs.

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Reducing ultrafiltration membrane fouling during potable water reuse using pre-ozonation

Water Research ◽

10.1016/j.watres.2017.08.030 ◽

2017 ◽

Vol 125 ◽

pp. 42-51 ◽

Cited By ~ 47

Author(s):

Hui Wang ◽

Minkyu Park ◽

Heng Liang ◽

Shimin Wu ◽

Israel J. Lopez ◽

...

Keyword(s):

Membrane Fouling ◽

Water Reuse ◽

Potable Water ◽

Ultrafiltration Membrane ◽

Ultrafiltration Membrane Fouling

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The Use of Computational Fluid Dynamics for Improving the Design and Operation of Water and Wastewater Treatment Plants

Water Science & Technology ◽

10.2166/wst.1999.0578 ◽

1999 ◽

Vol 40 (4-5) ◽

pp. 81-89 ◽

Cited By ~ 13

Author(s):

C. J. Brouckaert ◽

C. A. Buckley

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

Wastewater Treatment ◽

Potable Water ◽

Wastewater Treatment Plants ◽

Treatment Plant ◽

Water Treatment Plant ◽

Outer Wall ◽

Water And Wastewater Treatment ◽

Secondary Clarifier

Computational Fluid Dynamics (CFD) studies of a secondary clarifier at Durban's Northern Wastewater Treatment Works, and of a clarifier at the potable water treatment plant at Umzinto, a small town near Durban, have been undertaken with a view to improving their load capacities. In both cases the units are located in relatively old treatment plants, which face continually increasing loads due to population growth. Increasing the capacity of existing equipment, rather than installing new equipment, constitutes an efficient use of development capital. Although the two clarifiers have considerable design differences, the CFD studies indicated remarkably similar circulating flows, which concentrate up-flow near the outer wall of the clarifier in the region of the clarified water overflow weirs. Baffles were designed to disrupt the circulation so as to distribute up-flow over a wider area, thereby reducing the maximum vertical velocities. In the case of the wastewater secondary clarifier, the modification has been implemented, and evaluated in comparative tests involving an otherwise identical unmodified clarifier. In the case of the potable water clarifier, the modification has still to be implemented.

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Study on layout optimization of sewage outfalls: a case study of wastewater treatment plants in Xiamen

Scientific Reports ◽

10.1038/s41598-021-97756-9 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Cui Wang ◽

Zhouhua Guo ◽

Qingsheng Li ◽

Jing Fang

Keyword(s):

Wastewater Treatment ◽

Water Reuse ◽

Evaluation System ◽

Evaluation Method ◽

Wastewater Treatment Plants ◽

Comprehensive Evaluation ◽

Ecological Impact ◽

Layout Optimization ◽

Marine Environmental

AbstractIn order to protect the offshore environment and strengthen the comprehensive rectification of sewage outfalls, an evaluation method of regional sewage outfalls by combining the marine numerical simulation and comprehensive evaluation technology was constructed, considering the marine environmental capacity and the ecological impact of sewage discharge from outfalls on the marine eco-environment sensitive areas. Then the layout rationality of each outfall was evaluated and the discharge scale was optimized with a case study of existing sewage outfalls in Xiamen. The results show that, the comprehensive evaluation score of Yundang outfall was 3 points in 2025, evaluated as the outfall with irrational layout. In 2035, the comprehensive evaluation scores of Fenglin and Dalipu outfalls were 3 and 2 points respectively, evaluated as the outfall with irrational discharge scale. It is suggested to control the scale of expansion or increase the reclaimed water reuse rate in Jimei and Gaoqi Wastewater Treatment Plants. This method has enriched the evaluation system for layout optimization of sewage outfalls, providing scientific supports for comprehensive improvement of sewage outfalls and marine environmental management.

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Sewer Mining as a Distributed Intervention for Water-Energy-Materials in the Circular Economy Suitable for Dense Urban Environments: A Real World Demonstration in the City of Athens

Water ◽

10.3390/w13192764 ◽

2021 ◽

Vol 13 (19) ◽

pp. 2764

Author(s):

Argyro Plevri ◽

Klio Monokrousou ◽

Christos Makropoulos ◽

Christos Lioumis ◽

Nikolaos Tazes ◽

...

Keyword(s):

Wastewater Treatment ◽

Circular Economy ◽

Water Reuse ◽

Wastewater Treatment Plants ◽

Treatment Plant ◽

Urban Environments ◽

Treated Wastewater ◽

Aquifer Recharge ◽

Treatment Unit ◽

Plant Nursery

Water reuse and recycling is gaining momentum as a way to improve the circularity of cities, while recognizing the central role of water within a circular economy (CE) context. However, such interventions often depend on the location of wastewater treatment plants and the treatment technologies installed in their premises, while relying on an expensive piped network to ensure that treated wastewater gets transported from the treatment plant to the point of demand. Thus, the penetration level of treated wastewater as a source of non-potable supply in dense urban environments is limited. This paper focuses on the demonstration of a sewer mining (SM) unit as a source of treated wastewater, as part of a larger and more holistic configuration that examines all three ‘streams’ associated with water in CE: water, energy and materials. The application area is the Athens Plant Nursery, in the (water stressed) city of Athens, Greece. SM technology is in fact a mobile wastewater treatment unit in containers able to extract wastewater from local sewers, treat it directly and reuse at the point of demand even in urban environments with limited space. The unit consists of a membrane bioreactor unit (MBR) and a UV disinfection unit and produces high quality reclaimed water for irrigation and also for aquifer recharge during the winter. Furthermore, a short overview of the integrated nutrient and energy recovery subsystem is presented in order to conceptualise the holistic approach and circularity of the whole configuration. The SM technology demonstrates flexibility, scalability and replicability, which are important characteristics for innovation uptake within the emerging CE context and market.

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Influence of Hydraulic Loading Rate on Horizontal Zeolite Wetland Effluent Quality

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.573-574.659 ◽

2012 ◽

Vol 573-574 ◽

pp. 659-662

Author(s):

Hao Wang

Keyword(s):

Wastewater Treatment ◽

Loading Rate ◽

Wastewater Treatment Plants ◽

Treatment Plant ◽

Secondary Effluent ◽

Nitrogen And Phosphorus ◽

Nitrogen And Phosphorus Removal ◽

Hydraulic Loading Rate ◽

Effluent Quality ◽

Hydraulic Loading

In Tangshan area, the secondary effluent of wastewater treatment plants was used for this study. Horizontal zeolite wetland was carried out treating it. Hydraulic loading rate was the parameters for analyzing the nitrogen and phosphorus removal efficiency of pollutants from the secondary effluent of wastewater treatment plant. Zeolite constructed wetlands showed different behaviors for nitrogen and phosphorus removals.Under the optimum hydraulic loading rate, the primary pollutions were removed to a large extent.

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Combined Application of UV Photolysis and Ozonation with Biological Aerating Filter in Tertiary Wastewater Treatment

International Journal of Photoenergy ◽

10.1155/2012/140605 ◽

2012 ◽

Vol 2012 ◽

pp. 1-6 ◽

Cited By ~ 2

Author(s):

Zhaoqian Jing ◽

Shiwei Cao

Keyword(s):

Molecular Weight ◽

Wastewater Treatment ◽

Organic Pollutants ◽

Wastewater Treatment Plants ◽

Removal Rate ◽

Oxygen Demand ◽

Cod Removal ◽

Secondary Effluent ◽

Uv Photolysis ◽

Combined Application

To enhance the biodegradability of residual organic pollutants in secondary effluent of wastewater treatment plants, UV photolysis and ozonation were used in combination as pretreatment before a biological aerating filter (BAF). The results indicated that UV photolysis could not remove much COD (chemical oxygen demand), and the performance of ozonation was better than the former. With UV photolysis combined with ozonation (UV/O3), COD removal was much higher than the sum of that with UV photolysis and ozonation alone, which indicated that UV photolysis could efficiently promote COD removal during ozonation. This pretreatment also improved molecular weight distribution (MWD) and biodegradability greatly. Proportion of organic compounds with molecular weight (MW) <3 kDalton was increased from 51.9% to 85.9%. COD removal rates with BAF and O3/BAF were only about 25% and 38%, respectively. When UV/O3oxidation was combined with BAF, the average COD removal rate reached above 61%, which was about 2.5 times of that with BAF alone. With influent COD ranging from 65 to 84 mg/L, the effluent COD was stably in the scope of 23–31 mg/L. The combination of UV/O3oxidation with BAF was quite efficient in organic pollutants removal for tertiary wastewater treatment.

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Recent Progresses of Forward Osmosis Membranes Formulation and Design for Wastewater Treatment

Water ◽

10.3390/w11102043 ◽

2019 ◽

Vol 11 (10) ◽

pp. 2043 ◽

Cited By ~ 18

Author(s):

Goh ◽

Ismail ◽

Ng ◽

Abdullah

Keyword(s):

Wastewater Treatment ◽

Membrane Fouling ◽

Energy Efficient ◽

Potable Water ◽

Forward Osmosis ◽

Water Quality Standards ◽

Separation Technology ◽

Recent Developments ◽

Treatment Technologies ◽

Treatment Application

Production of potable water or reclaimed water with higher quality are in demand to address water scarcity issues as well as to meet the expectation of stringent water quality standards. Forward osmosis (FO) provides a highly promising platform for energy-efficient membrane-based separation technology. This emerging technology has been recognized as a potential and cost-competitive alternative for many conventional wastewater treatment technologies. Motivated by its advantages over existing wastewater treatment technologies, the interest of applying FO technology for wastewater treatment has increased significantly in recent years. This article focuses on the recent developments and innovations in FO for wastewater treatment. An overview of the potential of FO in various wastewater treatment application will be first presented. The contemporary strategies used in membrane designs and fabrications as well as the efforts made to address membrane fouling are comprehensively reviewed. Finally, the challenges and future outlook of FO for wastewater treatment are highlighted.

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Bacteria reduction and nutrient removal in small wastewater treatment plants by an algal biofilm

Water Science & Technology ◽

10.2166/wst.2003.0605 ◽

2003 ◽

Vol 47 (11) ◽

pp. 195-202 ◽

Cited By ~ 55

Author(s):

G. Schumacher ◽

T. Blume ◽

I. Sekoulov

Keyword(s):

Carbon Dioxide ◽

Wastewater Treatment ◽

Nutrient Removal ◽

Wastewater Treatment Plants ◽

Secondary Effluent ◽

Dissolved Carbon ◽

Attached Algae ◽

Dissolved Carbon Dioxide ◽

Algal Biofilm ◽

Faecal Bacteria

Attached algae settlement is frequently observed in effluents of wastewater treatment plants at locations with sufficient sunlight. For their growth they incorporate nutrients and the surface of the algal biofilm accumulates suspended solids from the clarified wastewater. During the photosynthesis process of algal biofilms oxygen is produced while dissolved carbon dioxide is consumed. This led to an increasing pH due to the change of the carbon dioxide equilibrium in water. The high pH causes precipitation of dissolved phosphates. Furthermore an extensive removal of faecal bacteria was observed in the presence of algae, which may be caused by the activity of algae. The experimental results indicate the high potential of these attached algae for polishing secondary effluent of wastewater treatment plants. Especially for small wastewater treatment plants a post connected stage for nutrient removal and bacteria reduction can be developed with the aid of an algal biofilm.

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