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 Direct Osmosis for Reverse Osmosis Fouling Control: Principles, Applications and Recent Developments

2009 ◽  
Vol 3 (1) ◽  
pp. 8-16 ◽  
Author(s):  
Jian-Jun Qin ◽  
Boris Liberman ◽  
Kiran A. Kekre ◽  
Ado Gossan
Keyword(s):  
Wastewater Treatment ◽  
Reverse Osmosis ◽  
Membrane Fouling ◽  
Chemical Potential ◽  
Water Desalination ◽  
Water And Wastewater Treatment ◽  
High Pressure Pump ◽  
Permeable Membrane ◽  
Fouling Control ◽  
Ro Membrane

Reverse osmosis (RO) has been widely applied in various water and wastewater treatment processes as a promising membrane technology. However, RO membrane fouling is a global issue, which limits it operating flux, decreases water production, increases power consumption and requires periodical membranes Cleaning-in-Place (CIP) procedure. This may result in low effectiveness, high cost and adds environmental issues related to the CIP solutions disposal. Forward osmosis (FO) or direct osmosis (DO) is the transport of water across a semi-permeable membrane from higher water chemical potential side to lower water chemical potential side, which phenomenon was observed in 1748. The engineered applications of FO/DO in membrane separation processes have been developed in food processing, wastewater treatment and seawater/brackish water desalination. In recent years, DO has been increasingly attractive for RO fouling control as it is highly efficient and environmentally friendly technique which is a new backwash technique via interval DO by intermittent injection of the high salinity solution without stoppage of high pressure pump or interruption of the operational process and allows keeping RO membrane continuously clean even in heavy bio-fouling conditions and operating RO membranes at high flux. This paper provides the state-of-the-art of the physical principles and applications of DO for RO fouling control as well as its strengths and limitations.

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.

Preliminary study on novel backwash cleaning for reverse osmosis fouling control in water reuse

2010 ◽  
Vol 10 (3) ◽  
pp. 296-301
Author(s):  
Jian-Jun Qin ◽  
Maung Htun Oo ◽  
Kiran A. Kekre
Keyword(s):  
Product Quality ◽  
Reverse Osmosis ◽  
Water Reuse ◽  
High Salinity ◽  
Full Scale ◽  
Elapse Time ◽  
Secondary Effluent ◽  
Fouling Control ◽  
Membrane Flux ◽  
Preliminary Study

We have demonstrated a novel backwash cleaning technique of direct osmosis (DO)-high salinity (HS) for reverse osmosis (RO) fouling control in water reuse. An UF-RO pilot system was continuously (24-h) operated on site with the secondary effluent as the feed over 4 months. The RO plant was run at 75% recovery and at the membrane flux of 17 l m−2 h−1 (LMH) to simulate the full scale NEWater production when DO-HS treatment was conducted once per day and five times per week during the last two months. Permeability of RO membranes as a function of elapse time of the pilot operation was monitored and compared over different durations. Impact of DO-HS treatment on RO product quality in terms of TOC and conductivity was investigated. It was concluded that the DO-HS treatment preliminarily demonstrated a benefit to low RO fouling rate by 2.5–4 times in 30–60 days without interruption on RO operation and impact on RO product quality.

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.

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 Effect of IX dosing on polypropylene and PVDF membrane fouling control

2013 ◽  
Vol 47 (11) ◽  
pp. 3827-3834 ◽  
Author(s):  
Darli Theint Myat ◽  
Max Mergen ◽  
Oliver Zhao ◽  
Matthew B. Stewart ◽  
John D. Orbell ◽  
...  
Keyword(s):  
Membrane Fouling ◽  
Pvdf Membrane ◽  
Fouling Control

scholarly journals Effect of Pre-Oxidation on Coagulation/Ceramic Membrane Treatment of Yangtze River Water

Membranes ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 369
Author(s):  
Shengji Xia ◽  
Xinran Zhang ◽  
Yuanchen Zhao ◽  
Fibor J. Tan ◽  
Pan Li ◽  
...  
Keyword(s):  
Water Treatment ◽  
Membrane Fouling ◽  
Membrane Filtration ◽  
Ceramic Membrane ◽  
Membrane Separation ◽  
Membrane System ◽  
Coagulation System ◽  
Fouling Control ◽  
Filtration System ◽  
Membrane Treatment

The membrane separation process is being widely used in water treatment. It is very important to control membrane fouling in the process of water treatment. This study was conducted to evaluate the efficiency of a pre-oxidation-coagulation flat ceramic membrane filtration process using different oxidant types and dosages in water treatment and membrane fouling control. The results showed that under suitable concentration conditions, the effect on membrane fouling control of a NaClO pre-oxidation combined with a coagulation/ceramic membrane system was better than that of an O3 system. The oxidation process changed the structure of pollutants, reduced the pollution load and enhanced the coagulation process in a pre-oxidation-coagulation system as well. The influence of the oxidant on the filtration system was related to its oxidizability and other characteristics. NaClO and O3 performed more efficiently than KMnO4. NaClO was more conducive to the removal of DOC, and O3 was more conducive to the removal of UV254.

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