Monitoring and control of biofouling in nanofiltration and reverse osmosis membranes

2008 ◽  
Vol 8 (4) ◽  
pp. 449-458 ◽  
Author(s):  
J. S. Vrouwenvelder ◽  
C. Hinrichs ◽  
A. R. Sun ◽  
F. Royer ◽  
J. A. M. van Paassen ◽  
...  
Keyword(s):  
Pressure Drop ◽  
Reverse Osmosis ◽  
Membrane Fouling ◽  
Formation Rate ◽  
Quality Parameters ◽  
Feed Water ◽  
Monitoring And Control ◽  
Cell Counts ◽  
Direct Cell ◽  
And Control

Water quality parameters such as ATP, total direct cell counts, AOC, biofilm formation rate and destructive membrane studies are not suitable for biofouling monitoring and prediction. Therefore, a monitor named membrane fouling simulator was developed. In a comparison study, the same feed channel pressure drop development in time and the same fouling accumulation was observed in spiral wound membrane elements and membrane fouling simulators. Chemical dosing to the membrane fouling simulator feed water showed that a biofouling inhibitor was not inhibiting biofouling, but was even contributing to biofouling. It is shown that other chemicals such as acid and antiscalants may contribute to biofouling as well. It was found that the feed spacer presence strongly influences the feed spacer channel pressure drop increase caused by biofilm accumulation: in nanofiltration and reverse osmosis systems biofouling is a feed spacer problem. A new set of monitors for membrane fouling studies and methods for biofouling monitoring are described. A state of the art on global membrane fouling simulator use is given.

Reverse Osmosis Technology for Wastewater Reuse

1991 ◽  
Vol 24 (9) ◽  
pp. 215-227 ◽  
Author(s):  
B. J. Mariñas
Keyword(s):  
Water Quality ◽  
Reverse Osmosis ◽  
Membrane Fouling ◽  
Quality Parameters ◽  
Operating Conditions ◽  
Water Quality Parameters ◽  
Feed Water ◽  
Hydraulic Pressure ◽  
Predominant Component ◽  
Percent Removal

Reverse osmosis technology has a great potential in the field of wastewater reclamation. A reverse osmosis plant includes the following processes: (1) feed water microfiltration and chemical conditioning, (2) membrane treatment, (3) permeate aeration, neutralization and disinfection, and (4) concentrate (liquid residue) treatment and disposal. The performance of reverse osmosis membranes depends on operating conditions and water quality parameters. Permeate productivity and contaminant removals increase with applied hydraulic pressure. Water quality parameters such as concentration, composition and pH also affect contaminant removal efficiencies. For example, the treatment of a simulated wastewater containing 10 mg/L of nitrate with a commercial polyamide-type reverse osmosis membrane resulted in membrane permeates containing approximately 0.05 mg/L of nitrate (or 99.5 percent removal) when sodium chloride was the major dissolved solid present in the feed water, and 1 mg/L (or 90 percent removal) when sodium sulfate was the predominant component. The removals of weak electrolyte contaminants are affected by feed water pH. For example, the removal of boron by a cellulose acetate-type membrane was reported to be greater than 99 percent at a pH of approximately 11, and less than 30 percent at a pH of 7. The practice of pre-treatment processes such as microfiltration and chemical conditioning can minimize performance deterioration resulting from membrane fouling by inorganic precipitates, organic macromolecules and microorganisms (biofouling).

scholarly journals A feasibility study on UV pretreatment for microfiltration and reverse osmosis membrane processes in wastewater reclamation

2013 ◽  
Vol 3 (3) ◽  
pp. 260-267
Author(s):  
Ho-Young Jeong ◽  
Yoon-Jin Kim ◽  
Ji-Hee Han ◽  
Dong-Ha Kim ◽  
Jinsik Sohn ◽  
...  
Keyword(s):  
Reverse Osmosis ◽  
Membrane Fouling ◽  
Treatment Options ◽  
Human Consumption ◽  
Feed Water ◽  
Reverse Osmosis Membrane ◽  
Wastewater Reclamation ◽  
Important Place ◽  
Quality Water ◽  
Small Footprint

Wastewater reclamation is where wastewater from various sources is purified so the water can be used by human consumption. Among many treatment options, membranes have gained an important place in wastewater reclamation. It allows the production of high quality water from wastewater, with a small footprint and affordable energy consumption. Nevertheless, membrane fouling is regarded as a serious problem due to the high fouling potential of wastewater. In this study, we applied ultraviolet (UV) processes as a pretreatment for membrane systems that are used for wastewater reclamation. Low pressure UV (LUV) and pulsed UV (PUV) were used to decompose or alter the organics in the feed water of the membranes. Effluent organic matter was characterized by total organic carbon (TOC) and UV absorbance (UVA). Also the effect of UV pretreatment on membrane fouling was investigated for microfiltration (MF) and reverse osmosis (RO) processes. The pretreatment of membranes using LUV or PUV was effective to control fouling of hollow fiber MF membranes. This is probably because of the reduction and modification of organics after UV treatments. However, the effect of UV pretreatment on RO flux was less significant, which is attributed to low fouling prophecy after MF treatment.

scholarly journals IoT for Monitoring and Control of Water Quality Parameters

2020 ◽  
Vol 14 (16) ◽  
pp. 4
Author(s):  
Fouzi Lezzar ◽  
Djamel Benmerzoug ◽  
Ilham Kitouni
Keyword(s):  
Water Quality ◽  
Water Quality Monitoring ◽  
Quality Parameters ◽  
Water Quality Parameters ◽  
Monitoring And Control ◽  
Cloud Processing ◽  
Data Collection Process ◽  
Standard Values ◽  
Processing And Storage ◽  
And Control

<p class="0abstract"><span lang="EN-US">This work presents an Internet of Things (IoT) solution to facilitate real time water quality monitoring by enabling the management of collected data from electronic sensors. Firstly, we present in detail problems encountered during the used data collection process. We discuss after the requirements from the water monitoring quality standpoint, data acquisition, cloud processing and data visualization to the end user. We designed a solution to minimize technicians’ visits to isolated water tower, we designed sensors achieving a lifespan of several years. The solution will be capable of scaling the processing and storage resources. This combination of technologies can cope with different types of environments. The system also provides a notification to a remote user, when there is a non-conformity of water quality parameters with the pre-defined set of standard values.</span></p>

Nanofiltration membrane fouling by conventionally treated surface water

2003 ◽  
Vol 3 (5-6) ◽  
pp. 183-190
Author(s):  
R. Liikanen ◽  
H. Kiuru ◽  
T. Tuhkanen ◽  
M. Nyström
Keyword(s):  
Water Treatment ◽  
Surface Water ◽  
Membrane Fouling ◽  
Feed Water ◽  
Water Characteristics ◽  
Treatment Train ◽  
Water Constituents ◽  
Filtration Unit ◽  
And Control ◽  
Chemical Water

Nanofiltration is a very effective technique for improving the removal of trace organics after a conventional chemical water treatment train. However, the fouling of the membranes decreases the applicability of the process, and thus, an understanding and control of membrane fouling are crucial for a more widespread use of nanofiltration in water treatment. The fouling of different nanofiltration membranes by pre-treated surface waters was investigated in a laboratory-scale filtration unit in this study. The results indicate that the traditional chemical treatment does not remove membrane foulants from the surface water. No correlation was found between the feed water constituents and nanofiltration performance, but most feed water components are expected to interact in membrane fouling. Actually, the performance of the nanofiltration process was more related to membrane than to feed water characteristics.

Production of process water using integrated membrane processes

2006 ◽  
Vol 60 (6) ◽  
Author(s):  
K. Karakulski ◽  
M. Gryta ◽  
M. Sasim
Keyword(s):  
Reverse Osmosis ◽  
Membrane Fouling ◽  
Tap Water ◽  
Industrial Effluents ◽  
Membrane Distillation ◽  
Process Water ◽  
Feed Water ◽  
Reverse Osmosis Membrane ◽  
Permeate Flux ◽  
Membrane Processes

AbstractApplication of ultrafiltration, nanofiltration, reverse osmosis, membrane distillation, and integrated membrane processes for the preparation of process water from natural water or industrial effluents was investigated. A two-stage reverse osmosis plant enabled almost complete removal of solutes from the feed water. High-purity water was prepared using the membrane distillation. However, during this process a rapid membrane fouling and permeate flux decline was observed when the tap water was used as a feed. The precipitation of deposit in the modules was limited by the separation of sparingly soluble salts from the feed water in the nanofiltration. The combined reverse osmosis—membrane distillation process prevented the formation of salt deposits on the membranes employed for the membrane distillation. Ultrafiltration was found to be very effective removing trace amounts of oil from the feed water. Then the ultrafiltration permeate was used for feeding of the remaining membrane modules resulting in the total removal of oil residue contamination. The ultrafiltration allowed producing process water directly from the industrial effluents containing petroleum derivatives.

Hybrid TiO2 photocatalytic oxidation and ultrafiltration for humic acid removal and membrane fouling control

2011 ◽  
Vol 11 (3) ◽  
pp. 324-332 ◽  
Author(s):  
Hongwei Bai ◽  
Darren Delai Sun
Keyword(s):  
Humic Acid ◽  
Membrane Fouling ◽  
Photocatalytic Oxidation ◽  
Removal Rate ◽  
Optimal Choice ◽  
Feed Water ◽  
Permeate Flux ◽  
Hydrophobic Membrane ◽  
Fouling Control ◽  
And Control

Hybrid UV/TiO2 photocatalytic oxidation (PCO) and ultrafiltration (UF) process (PCO-UF) were used to remove humic acid (HA) and control membrane fouling. The PCO-UF process showed advantages in terms of higher removal rate of HA, higher permeate flux and less membrane fouling over UF alone and PCO alone on HA removal and membrane fouling control. Membrane material and pH of feed water were shown to be the influence on the performance of PCO-UF process. It was observed that higher pH of HA feed water and a hydrophobic membrane lead to better removal of HA with relatively higher permeate flux. The experimental results in this study demonstrated that 100 kDa ultraflic UF membrane and pH 9 of HA feed water would be the optimal choice for HA removal in the combined PCO-UF process.

Design considerations for wastewater treatment by reverse osmosis

2005 ◽  
Vol 51 (6-7) ◽  
pp. 473-482 ◽  
Author(s):  
C.R. Bartels ◽  
M. Wilf ◽  
K. Andes ◽  
J. Iong
Keyword(s):  
Wastewater Treatment ◽  
Calcium Phosphate ◽  
Reverse Osmosis ◽  
Membrane Fouling ◽  
Urban Areas ◽  
Large Scale ◽  
Membrane Surface ◽  
Feed Water ◽  
High Quality ◽  
Quality Water

Reverse Osmosis is finding increasing use for the treatment of municipal and industrial wastewaters due to the growing demand for high quality water in large urban areas. The growing success of membranes in this application is related to improved process designs and improved membrane products. Key factors which have been determined to result in successful operation of large-scale plants will be discussed. Factors which play a key role in the use of RO membranes include ultra or microfiltration pretreatment, low fouling membranes, flux rate, recovery and control of fouling and scaling. In particular, high flux rates can be used when UF or MF pretreatment is used. These technologies remove most of the suspended particles that would normally cause heavy fouling of lead elements. Typically, fluxes in the range of 17–21 lmh lead to cleaning frequencies in the range of 3–4 months. By combining the use of membrane pretreatment and chloramination of the feed water through chlorine addition, two of the primary sources of RO membrane fouling can be controlled. The use of chloramine has become a proven means to control biofouling in a membrane for wastewater applications. The other significant problems for RO membranes result from organics fouling by dissolved organics and scaling due to saturation of marginally soluble salts. The former can be a significant problem for membranes, due to the strong attraction forces. To some extent, these can be mitigated by making the membrane surface more hydrophilic or changing the charge of the membrane surface. To minimize fouling, many plants are turning to low fouling membranes. Extensive studies have demonstrated that the membrane surface is hydrophilic, neutrally charged over a broad pH range, and more resistant to organic adsorption. Also, an analysis of the potential scaling issues will be reviewed. In particular, calcium phosphate has been found to be one of the key scalants that will limit RO system recovery rate. Calcium phosphate concentrations can reach high values in many wastewaters, and scaling of this compound is not often modeled in most RO projection software. Various process options will be presented to evaluate the most economic means of avoiding phosphate scaling. Finally, data from major RO wastewater treatment plants will be presented to show how the RO membranes operate under actual conditions, utilizing many of these design features. Long term data from the 2.6 mgd Bedok demonstration Plant demonstrate that the RO membranes operate consistently on wastewater. Experiences from the 8.5 mgd (32,000 m3/day) Bedok and 10.5 mgd (40,000 m3/day) Kranji plants will also be presented. These large plants started operation in the fall of 2002 and have demonstrated an effective means to reclaim high quality water from difficult source waters, such as municipal wastewaters.

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 Membrane Fouling in Algal Separation Processes: A Review of Influencing Factors and Mechanisms

2021 ◽  
Vol 3 ◽  
Author(s):  
Andres Felipe Novoa ◽  
Johannes S. Vrouwenvelder ◽  
Luca Fortunato
Keyword(s):  
Membrane Fouling ◽  
Control Strategies ◽  
Membrane Surface ◽  
Cost Effective ◽  
Dynamic Responses ◽  
Feed Water ◽  
Operational Conditions ◽  
Term Operation ◽  
Fouling Control ◽  
And Control

The use of algal biotechnologies in the production of biofuels, food, and valuable products has gained momentum in recent years, owing to its distinctive rapid growth and compatibility to be coupled to wastewater treatment in membrane photobioreactors. However, membrane fouling is considered a main drawback that offsets the benefits of algal applications by heavily impacting the operation cost. Several fouling control strategies have been proposed, addressing aspects related to characteristics in the feed water and membranes, operational conditions, and biomass properties. However, the lack of understanding of the mechanisms behind algal biofouling and control challenges the development of cost-effective strategies needed for the long-term operation of membrane photobioreactors. This paper reviews the progress on algal membrane fouling and control strategies. Herein, we summarize information in the composition and characteristics of algal foulants, namely algal organic matter, cells, and transparent exopolymer particles; and review their dynamic responses to modifications in the feedwater, membrane surface, hydrodynamics, and cleaning methods. This review comparatively analyzes (i) efficiency in fouling control or mitigation, (ii) advantages and drawbacks, (iii) technological performance, and (iv) challenges and knowledge gaps. Ultimately, the article provides a primary reference of algal biofouling in membrane-based applications.

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