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

2018 ◽  
Vol 15 (9) ◽  
pp. 1960 ◽  
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.

scholarly journals Removal Characteristics of N-Nitrosamines and Their Precursorsby Pilot-Scale Integrated Membrane Systems for Water Reuse

2018 ◽  
Author(s):  
Haruka Takeuchi ◽  
Naoyuki Yamashita ◽  
Norihide Nakada ◽  
Hiroaki Tanaka
Keyword(s):  
Membrane Fouling ◽  
Water Reuse ◽  
Pilot Scale ◽  
Feed Water ◽  
Size Distributions ◽  
Membrane Systems ◽  
Chemical Cleaning ◽  
Membrane Processes ◽  
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) / RO; (2) sand filtration/three-step RO; and (3) ultrafiltration (UF) / NF and UF / RO. Variable removal of N-nitrosodimethylamine (NDMA) by the RO membrane processes could be attributable to membrane fouling and feed water temperature. The effect of membrane fouling on N-nitrosamines removal was extensively evaluated at one of the plants by conducting one month of operation and chemical cleaning of the RO membrane element. Membrane fouling enhanced N-nitrosamines removal by the pilot-scale RO membrane process. This finding contributes to better understanding of variable removal of NDMA by RO membrane processes. This study also investigated the removal characteristics of N-nitrosamines precursors. The NF and RO membrane processes greatly reduced NDMA formation potential (FP), but the UF process had little effect. The contributions of MF, NF, and RO membrane processes for reducing FPs of NDMA, N-nitrosopyrrolidine (NPYR) and N-nitrosodiethylamine (NDEA) were different, suggesting different size distributions of their precursors.

scholarly journals Microcoagulation improved the performance of the UF–RO system treating the effluent from a coastal municipal wastewater treatment plant: a pilot-scale study

2021 ◽  
Author(s):  
Tong Yu ◽  
Chenlu Xu ◽  
Feng Chen ◽  
Haoshuai Yin ◽  
Hao Sun ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plant ◽  
Membrane Fouling ◽  
Municipal Wastewater ◽  
Treatment Plant ◽  
Pilot Scale ◽  
Contaminant Removal ◽  
Municipal Wastewater Treatment ◽  
Municipal Wastewater Treatment Plant ◽  
Ro Membrane

Abstract Microcoagulation has recently been considered as a promising pretreatment for an ultrafiltration (UF) process from numerous studies. To investigate the effects of microcoagulation on the performance of the UF–reverse osmosis (RO) system treating wastewater with high and fluctuant salinity, different dosages of coagulant (poly-aluminum chloride) were added prior to the UF unit in a pilot-scale UF–RO system for a 10-week period operation. Microcoagulation obviously improved the contaminant removal and cleaning efficiencies, including water backwash, chemical enhanced backwash and cleaning in place processes. Organic fouling was dominated during the initial stage of the RO membrane fouling. The microbial communities of water samples and foulant on the RO membrane were similar to those of seawater and foulant on the RO membranes from seawater RO plants. The microbial community of the foulant on the membrane was similar to that of UF permeate and RO concentrate. These results demonstrated that microcoagulation could improve the performance of the UF–RO system treating the effluent with high and fluctuant salinity from a coastal municipal wastewater treatment plant.

scholarly journals Enhanced Removal of Organic Pollutants and Reactive Dye in Polyethersulfone Submerged Membrane Bioreactor (PES-SMBR) for Textile Wastewater

2021 ◽  
Vol 16 (1) ◽  
pp. 329-341
Author(s):  
Tukaram P. Chavan ◽  
Ganpat B. More ◽  
Sanjaykumar R. Thorat
Keyword(s):  
Membrane Fouling ◽  
Membrane Bioreactor ◽  
Textile Wastewater ◽  
Pilot Scale ◽  
Reactive Dye ◽  
Hollow Fibre ◽  
Flow Mode ◽  
Permeate Flux ◽  
Chemical Cleaning ◽  
Submerged Membrane Bioreactor

The present investigation was carried out to assess the operation of a pilot-scale submerged membrane bioreactor (SMBR) for the treatment of reactive dye and textile wastewater. The operation of SMBR model was conducted by using a polyethersulfone (PES) hollow fibre membrane with continuous flow mode at different HRTs at 8, 6 and 4 h, for 90 days. During the entire operation, the average permeate flux, TMP, F/M ratio and OLR was found to be 19 (L/m²/h), 2.6 (psi), 0.10 (g BOD/(g MLSS•d) and 0.89 (kg BOD/m³.d), respectively. The variations in the permeate flux, TMP, F/M ratio and OLR have not adversely effects on the operation of the SMBR model. Throughout the entire operation, despite the TP, TDS and conductivity, the high amount of COD (82%), BOD (86%), NO3-N (79%), TSS (98%), turbidity (97%) and colour (79%), removal was achieved. The permeate flux was declined by membrane fouling and it was recovered by chemical cleaning as well as regular backwashing during the entire operation. The results obtained from the study concluded that the hollow fibre ultrafiltration polyethersulfone (PES) membrane shows good performance while treating textile wastewater along with reactive dye solution.

An integrated wastewater reuse concept combining natural reclamation techniques, membrane filtration and metal oxide adsorption

2008 ◽  
Vol 57 (6) ◽  
pp. 909-914 ◽  
Author(s):  
A. Sperlich ◽  
X. Zheng ◽  
M. Jekel ◽  
M. Ernst
Keyword(s):  
Membrane Fouling ◽  
Water Reuse ◽  
Membrane Filtration ◽  
Sodium Hydroxide Solution ◽  
Wastewater Reuse ◽  
Ferric Hydroxide ◽  
Operation Time ◽  
Pilot Scale ◽  
Phosphorus Concentration ◽  
Total Phosphorus Concentration

In a Sino-German research project, a sustainable water reclamation concept was developed for different applications of municipal water reuse at the Olympic Green 2008 in Beijing, China. Results from pilot-scale experiments in Beijing and Berlin show that selective nutrient removal by adsorption onto granular ferric hydroxide (GFH) after a membrane bioreactor (MBR) can maintain a total phosphorus concentration of <0.03 μg L−1 P, thus preventing eutrophication of artificial lakes. Operation time of GFH adsorption columns can be extended by regeneration using sodium hydroxide solution. A subsequent ultrafiltration (UF) membrane after bank filtration creates an additional barrier for pathogens and allows for further urban reuse applications such as toilet flushing. Short term bank / bio-filtration prior to UF is shown to effectively remove biopolymers and reduce membrane fouling.

Innovative large-diameter RO system for water reclamation and seawater desalination

2008 ◽  
Vol 8 (1) ◽  
pp. 93-99 ◽  
Author(s):  
How Yong Ng ◽  
Kwee Guan Tay ◽  
Seng Chye Chua ◽  
Harry Seah
Keyword(s):  
Membrane Fouling ◽  
Large Diameter ◽  
Pressure Vessels ◽  
Feed Water ◽  
Water Reclamation ◽  
Membrane Element ◽  
Permeate Flux ◽  
Seawater Desalination ◽  
Feed Pressure ◽  
Flow Distributor

This study presents the performance of two innovative large-diameter (16-inch) demonstration reverse osmosis systems (known as Super-Flux RO systems) for water reclamation and seawater desalination in Singapore. Each 16-inch membrane element of the Super-Flux demonstration RO systems was fitted with patented flow distributors on both ends of each RO element to achieve even distribution of feed water into each membrane element. Electrical coils were embedded into the pressure vessels to produce electromagnetic field for fouling mitigation. Computational fluid dynamics results had verified that feed water was more evenly distributed at membrane inlet with the new flow distributor, compared to the commonly used anti-telescoping device. The operating data collected from the two demonstration RO systems over a period of 1,200 operating hours showed the excellent performance of the Super-Flux RO system regardless of the type of feed water. Both demonstration RO systems produced high quality permeate water and did not show any signs of membrane fouling, i.e., feed pressure, salt rejection and average permeate flux were consistent in the test periods. The average permeate flux of the Super-Flux demonstration RO system for water reclamation was about 2.6 times the value of the existing conventional 8-inch full-scale RO system.

scholarly journals Characterization of secondary treated effluents for tertiary membrane filtration and water recycling

2012 ◽  
Vol 2 (2) ◽  
pp. 74-83 ◽  
Author(s):  
C. Ayache ◽  
M. Pidou ◽  
W. Gernjak ◽  
Y. Poussade ◽  
J.-P. Croué ◽  
...  
Keyword(s):  
Water Quality ◽  
Organic Matter ◽  
Membrane Fouling ◽  
Membrane Filtration ◽  
Low Pressure ◽  
Hollow Fibre ◽  
Feed Water ◽  
Chemical Cleaning ◽  
Characterization Methods ◽  
Secondary Effluents

This study evaluates the impacts of water quality from three different secondary effluents on low pressure membrane fouling. Effluent organic matter (EfOM) has been reported by previous studies as responsible for membrane fouling. However, the contribution of the different components of EfOM to membrane fouling is still not well understood. In order to improve and optimize treatment processes, characterization and quantification of the organic matter are important. The characterization methods used in this study are liquid chromatography coupled with an organic detector (LC-OCD) and excitation emission matrix fluorescence spectroscopy (EEM). A bench-scale hollow fibre membrane system was used to identify the type of fouling depending on the feed water quality. Results showed no measurable dissolved organic carbon removal by the membranes for the three secondary effluents. Biopolymers and humic-like substances found in different proportions in the three effluents were partially retained by the membranes and were identified to contribute significantly to the flux decline of the low pressure membranes. The observed fouling was determined to be reversible by hydraulic backwashing for two effluents and only by chemical cleaning for the third effluent.

Optimization of direct-osmosis–high-salinity cleaning for reverse osmosis fouling control in water reuse

2010 ◽  
Vol 10 (5) ◽  
pp. 800-805 ◽  
Author(s):  
Jian-Jun Qin ◽  
Maung Htun Oo ◽  
Kiran A. Kekre ◽  
Harry Seah
Keyword(s):  
Membrane Fouling ◽  
Driving Force ◽  
Water Reuse ◽  
Systematic Approach ◽  
High Salinity ◽  
Proof Of Concept ◽  
Salt Consumption ◽  
Fouling Control ◽  
Injection Duration ◽  
Ro Membrane

This paper focuses on the systematic approach adopted towards optimizing the salt consumption when using direct-osmosis–high-salinity (DO-HS) cleaning method for RO membranes in water reuse application. Trials were carried out on a pilot RO system with a capacity of 50 m3/day. Initially, proof of concept for the DO-HS method in water reuse application was established wherein the profile of osmotic driving force for DO backwash, DO backwash flow during HS injection, removal of foulants with DO-HS treatment and lower RO fouling rate with the DO-HS method were demonstrated. 6 months of trials further demonstrated that RO membrane fouling rate and CIP frequency could be significantly reduced with the DO-HS method and there was no impact on the performance of RO membranes. Further trials were carried out focusing of salt requirements and it was found that salt injection duration could be reduced by 68% while the 48-h interval of salt injection was not recommended. Currently, the salt consumption has been reduced from the initial at 0.5 ton to the current at 0.16 ton as per 10,000 m3/day production. The study is ongoing to achieve the target of 0.05 ton for ease of operation.

scholarly journals Aggravated biofouling caused by chlorine disinfection in a pilot-scale reverse osmosis treatment system of municipal wastewater

2021 ◽  
Author(s):  
Li-Wei Luo ◽  
Yin-Hu Wu ◽  
Yun-Hong Wang ◽  
Xin Tong ◽  
Yuan Bai ◽  
...  
Keyword(s):  
Reverse Osmosis ◽  
Relative Abundance ◽  
Membrane Fouling ◽  
Municipal Wastewater ◽  
Water Pressure ◽  
Pilot Scale ◽  
Resistant Bacteria ◽  
Feed Water ◽  
Chlorine Disinfection ◽  
Key Species

Abstract The reverse osmosis (RO) system is widely applied to produce reclaimed water for high-standard industrial use. Chlorine disinfection is the main biofouling control method in the RO systems for wastewater reclamation. However, researchers reported the adverse effects of chlorine disinfection which aggravated biofouling in laboratory-scale RO systems. In this study, four parallel 4-inch spiral wound RO membranes were used to study the effect of chlorine on biofouling in a pilot-scale RO system. The free chlorine dosages in four experimental groups were 0, 1, 2 and 5 mg/L, respectively. After continuous chlorination and dechlorination, the feed water entered the RO system. It was found that chlorine pretreatment caused a 1.9–36.7% increase in relative feed water pressure of the RO system, suggesting that chlorine aggravated the membrane fouling in the pilot-scale RO system. The microbial community structures of living bacteria in the feed water of the RO system were determined by the PMA (propidium monoazide)-PCR method and showed that the relative abundance of chlorine-resistant bacteria (CRB) was significantly increased after disinfection. Nine major genera which maintained higher relative abundance in experimental groups with high chlorine dosage were considered as possible key species causing membrane fouling, including Pedobacter, Clostridium and Bradyrhizobium.

scholarly journals Evaluation of fouling and RO performance for MBR treated fruit wastewater

2020 ◽  
Vol 82 (11) ◽  
pp. 2282-2295
Author(s):  
A. T. Jamal-Uddin ◽  
R. G. Zytner
Keyword(s):  
Best Management Practices ◽  
Membrane Fouling ◽  
Water Reuse ◽  
Management Practices ◽  
Membrane Surface ◽  
Good Alternative ◽  
Sorption Process ◽  
Fruit Processing ◽  
Ro Membrane ◽  
The Impact

Abstract Fruit processing facilities are looking for ways to reduce water consumption to counter the impact of climate change. A good alternative is an MBR system to treat the processing wastewater, followed by tertiary treatment using a reverse osmosis (RO) unit to enable water reuse. However, fouling of the RO membrane causes operational challenges. As a result, experiments were completed on treated fruit processing wastewater to identify the causes of fouling that originated from the MBR effluent and develop best management practices (BMPs) to minimize fouling of the RO membrane. Physical and chemical analyses along with visual inspection of the membrane surface using scanning electron microscopy (SEM), energy diffusive X-ray (EDX) and Fourier transform infrared (FTIR) spectroscopy were completed. The issue of RO membrane fouling and subsequent flux decline was directly related to the presence of soluble microbial products, specifically dissolved organic matter (DOM) in the MBR effluent. The developed BMPs show that the previously completed enhanced coagulation-GAC sorption process, when combined with an online non-chemical flushing regimen and proper membrane preservation, keeps the flux readings high, resolving frequent fouling and cleaning problems of the RO membrane.

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