Application of the Ultrafiltration and Photooxidation Process for the Treatment of Rainwater

AbstractAs water resources become increasingly scarce, the concept of water reuse is gaining importance. Recently, attention has been paid to the use of rainwater as an alternative water resource. Part of this study, laboratory-scale experiments were conducted to evaluate the effectiveness and efficiency of the ultrafiltration process. The aim of the research was to assess the influence of pollutants from various roof coverings on the ultrafiltration process and the occurrence of membrane fouling. Additionally, the rainwater disinfection process was performed using UV radiation. Analysis of rainwater collected from various roofing materials, evaluating rainwater treatment by ultrafiltration in a cross-flow system, determination of the effectiveness and efficiency of the UF membrane, and additional disinfection of rainwater using UV radiation were carried out. Rainwater was collected from various roofing materials, such as steel roof tiles (RW1), bituminous shingles (RW2), and tar paper roofing (RW3). The treatment efficiency of ultrafiltration was evaluated by monitoring typical quality parameters: color, turbidity, COD, TOC, absorbance of UV254, ammonium, conductivity, and pH. Coliform bacteria, Escherichia coli and Enterococci, were monitored as total number of microorganisms at 22 ± 2 °C after 72 h. As expected, a significant reduction in individual parameters was recorded. COD of rainwater decreased in RW1 by 59%, in RW2 by 69%, and in RW3 by 74%. The ultrafiltration process ensured the complete retention of the coliform bacteria and E. coli. Complete elimination of microorganisms was demonstrated when the ultrafiltration process and UV radiation disinfection were combined.

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Membrane fouling performance of Fe-based coagulation-ultrafiltration process: Effect of sedimentation time

Environmental Research ◽

10.1016/j.envres.2021.110756 ◽

2021 ◽

Vol 195 ◽

pp. 110756

Author(s):

Yanyan Ding ◽

Tong Li ◽

Kaipei Qiu ◽

Baiwen Ma ◽

Ruijun Wu

Keyword(s):

Membrane Fouling ◽

Sedimentation Time ◽

Ultrafiltration Process

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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 Chao Phraya River Basin: water quality and anthropogenic influences

Water Science & Technology Water Supply ◽

10.2166/ws.2018.167 ◽

2018 ◽

Vol 19 (5) ◽

pp. 1287-1294 ◽

Cited By ~ 2

Author(s):

Nuanchan Singkran ◽

Pitchaya Anantawong ◽

Naree Intharawichian ◽

Karika Kunta

Keyword(s):

Water Quality ◽

Land Use ◽

River Basin ◽

River Mouth ◽

Oxygen Demand ◽

Quality Parameters ◽

Paddy Fields ◽

Coliform Bacteria ◽

Wet Season ◽

Chao Phraya River

Abstract Land use influences and trends in water quality parameters were determined for the Chao Phraya River, Thailand. Dissolved oxygen (DO), biochemical oxygen demand (BOD), and nitrate-nitrogen (NO3-N) showed significant trends (R2 ≥ 0.5) across the year, while total phosphorus (TP) and faecal coliform bacteria (FCB) showed significant trends only in the wet season. DO increased, but BOD, NO3-N, and TP decreased, from the lower section (river kilometres (rkm) 7–58 from the river mouth) through the middle section (rkm 58–143) to the upper section (rkm 143–379) of the river. Lead and mercury showed weak/no trends (R2 < 0.5). Based on the river section, major land use groups were a combination of urban and built-up areas (43%) and aquaculture (21%) in the lower river basin, paddy fields (56%) and urban and built-up areas (21%) in the middle river basin, and paddy fields (44%) and other agricultural areas (34%) in the upper river basin. Most water quality and land use attributes had significantly positive or negative correlations (at P ≤ 0.05) among each other. The river was in crisis because of high FCB concentrations. Serious measures are suggested to manage FCB and relevant human activities in the river basin.

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Gas sparged cross-flow microfiltration of biologically treated wastewater

Water Science & Technology ◽

10.2166/wst.2000.0636 ◽

2000 ◽

Vol 41 (10-11) ◽

pp. 173-180 ◽

Cited By ~ 8

Author(s):

L. Vera ◽

S. Delgado ◽

S. Elmaleh

Keyword(s):

Shear Stress ◽

Membrane Fouling ◽

Cross Flow ◽

Solid Content ◽

Treated Wastewater ◽

Inorganic Membrane ◽

Form Complex ◽

Cross Flow Filtration ◽

Mass Transport Process ◽

Flow Filtration

A novel technique was tested for reducing tubular mineral membrane fouling by injecting gas into a cross-flow stream. The injected gas is thought to form complex hydrodynamic conditions inside the microfiltration module, which increase the wall shear stress, preventing the membrane fouling and enhancing the microfiltration mass transfer. The experimental study was carried out with biologically treated wastewater filtered through a tubular inorganic membrane (Carbosep M14). The flux, monotonously increasing with gas velocity, was more than tripled. New dimensionless quantities of shear stress number and resistance number were developed by generalisation of the dimensional analysis already carried out for the steady state flux of classical unsparged cross-flow filtration. A unique formalism allowed then interpreting the experimental results of both classical diphasic filtration and sparged filtration. The main limiting mass transport process was due to the solid content.

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Comparison of four types of membrane bioreactor systems in terms of shear stress over the membrane surface using computational fluid dynamics

Water Science & Technology ◽

10.2166/wst.2013.515 ◽

2013 ◽

Vol 68 (12) ◽

pp. 2534-2544 ◽

Cited By ~ 4

Author(s):

N. Ratkovich ◽

T. R. Bentzen

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

Membrane Fouling ◽

Two Phase Flow ◽

Membrane Surface ◽

Cross Flow ◽

Membrane Bioreactors ◽

Phase Flow ◽

Two Phase ◽

Computational Fluid Dynamics Cfd

Membrane bioreactors (MBRs) have been used successfully in biological wastewater treatment to solve the perennial problem of effective solids–liquid separation. A common problem with MBR systems is clogging of the modules and fouling of the membrane, resulting in frequent cleaning and replacement, which makes the system less appealing for full-scale applications. It has been widely demonstrated that the filtration performances in MBRs can be greatly improved with a two-phase flow (sludge–air) or higher liquid cross-flow velocities. However, the optimization process of these systems is complex and requires knowledge of the membrane fouling, hydrodynamics and biokinetics. Modern tools such as computational fluid dynamics (CFD) can be used to diagnose and understand the two-phase flow in an MBR. Four cases of different MBR configurations are presented in this work, using CFD as a tool to develop and optimize these systems.

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Removal Characteristics of N-Nitrosamines and Their Precursors by Pilot-Scale Integrated Membrane Systems for Water Reuse

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph15091960 ◽

2018 ◽

Vol 15 (9) ◽

pp. 1960 ◽

Cited By ~ 11

Author(s):

Haruka Takeuchi ◽

Naoyuki Yamashita ◽

Norihide Nakada ◽

Hiroaki Tanaka

Keyword(s):

Membrane Fouling ◽

Water Reuse ◽

Pilot Scale ◽

Feed Water ◽

Water Reclamation ◽

Size Distributions ◽

Membrane Systems ◽

Chemical Cleaning ◽

Ro Membrane ◽

Feed Water Temperature

This study investigated the removal characteristics of N-Nitrosamines and their precursors at three pilot-scale water reclamation plants. These plants applies different integrated membrane systems: (1) microfiltration (MF)/nanofiltration (NF)/reverse osmosis (RO) membrane; (2) sand filtration/three-stage RO; and (3) ultrafiltration (UF)/NF and UF/RO. Variable removal of N-Nitrosodimethylamine (NDMA) by the RO processes could be attributed to membrane fouling and the feed water temperature. The effect of membrane fouling on N-Nitrosamine removal was extensively evaluated at one of the plants by conducting one month of operation and chemical cleaning of the RO element. Membrane fouling enhanced N-Nitrosamine removal by the pilot-scale RO process. This finding contributes to better understanding of the variable removal of NDMA by RO processes. This study also investigated the removal characteristics of N-Nitrosamine precursors. The NF and RO processes greatly reduced NDMA formation potential (FP), but the UF process had little effect. The contributions of MF, NF, and RO processes for reducing FPs of NDMA, N-Nitrosopyrrolidine and N-Nitrosodiethylamine were different, suggesting different size distributions of their precursors.

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Performance and properties of coking nanofiltration concentrate treatment and membrane fouling mitigation by an Fe(ii)/persulfate-coagulation-ultrafiltration process

RSC Advances ◽

10.1039/c8ra10094b ◽

2019 ◽

Vol 9 (27) ◽

pp. 15277-15287

Author(s):

Ming Yang ◽

Jiabin Chen ◽

Boyu Peng ◽

Zhenjiang Yu ◽

Huaqiang Chu ◽

...

Keyword(s):

Membrane Fouling ◽

Fouling Mitigation ◽

Concentrate Treatment ◽

Nanofiltration Concentrate ◽

Ultrafiltration Process

The removal effect of organics and the feasibility of membrane fouling mitigation with Fe(ii)/PS-PFS coupling technology.

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Recycling of Reverse Osmosis Concentrates to the Membrane Bioreactor in the MBR-RO Process for Water Reuse: effect on mbr performances

Revue des sciences de l eau ◽

10.7202/1040057ar ◽

2017 ◽

Vol 30 (1) ◽

pp. 1-10 ◽

Cited By ~ 1

Author(s):

Thi Thu Nga Vu ◽

Manon Montaner ◽

Christelle Guigui

Keyword(s):

Organic Matter ◽

Reverse Osmosis ◽

Membrane Fouling ◽

Water Reuse ◽

High Performance ◽

Membrane Bioreactor ◽

Membrane System ◽

Size Exclusion ◽

Ro Concentrate ◽

The Impact

Wastewater effluents can be treated by an integrated membrane system combining membrane bioreactor (MBR) and reverse osmosis (RO) for effective removal of micropollutants in the field of high-quality water reuse. However, discharging the RO concentrate waste stream directly into the natural environment could lead to serious problems due to the toxic components contained in the concentrates (micropollutants, salts, organic matter). A possible solution could be the recirculation of RO concentrate waste to the MBR. However, such an operation should be studied in detail since the recirculation of non-biodegradable organic matter or high concentrations of salts and micropollutants could directly or indirectly contribute to MBR membrane fouling and modification of the biodegradation activity. In this context, the work reported here focused on the recirculation of such concentrates in an MBR, paying specific attention to MBR membrane fouling. Lab-scale experiments were performed on a continuous MBR-RO treatment line with RO concentrate recirculation. The main goal was to determine the recovery of the RO unit and of the global process that maintained good process performance in terms of biodegradation and MBR fouling. The results demonstrate that the impact of the toxic flow on activated sludge depends on the recovery of the RO step but the same trends were observed regardless of the organic matter and salt contents of the concentrates: the concentration of proteins increased slightly. Size-exclusion high performance liquid chromatography (HPLC-SEC) was employed to study the effects of RO concentrate on the production of protein-like soluble microbial products (SMPs) and demonstrated a significant peak of protein-like substances corresponding to 10-100 kDa and 100-1 000 kDa molecules in the supernatant. Thus a significant increase in the propensity for sludge fouling was observed, which could be attributed to the increased quantity of protein-like substances. Finally, the effect of the concentrate on sludge activity was studied and no significant effect was observed on biodegradation, indicating that the return of the concentrate to the MBR could be a good alternative.

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