A study on membrane fouling due to algal deposition

2000 ◽  
Vol 41 (10-11) ◽  
pp. 327-335 ◽  
Author(s):  
S. Babel ◽  
S. Takizawa
Keyword(s):  
Organic Matter ◽  
Membrane Fouling ◽  
Cell Lysis ◽  
Chemical Cleaning ◽  
Membrane Cleaning ◽  
Treatment Techniques ◽  
Ozone Pretreatment ◽  
Extensive Cell ◽  
Pre Treatment ◽  
Physical And Chemical

Batch filtration experiments in dead-end mode were carried out to investigate the membrane fouling phenomenon due to Chlorella deposition and to analyse the effectiveness of pretreatment techniques to control membrane fouling. Experiments were also conducted to identify efficient and effective physical and chemical methods for cleaning the membrane. For both cellulose acetate and PVDF membranes, the effect of algal concentration was found similar. Initially when the deposition was less, the flux was high and the resistance was very low or negligible. As the deposition increased, the resistance increased exponentially. With further increase in deposition, the resistance increases linearly at a constant rate. Among the three pre-treatment techniques studied, coagulation with alum and ozonation were effective in controlling the fouling of membrane. Chlorine pretreatment was not effective in reducing the algal cake resistance because it brought about an extensive cell lysis. Photographs taken by Scanning Electron Microscope (SEM) showed damage to the cell surface architecture and release of organic matter to the medium after chlorination. Ozone pretreatment was more effective than chlorine in disintegrating only the extracelluar organic matter (EOM) without causing cell lysis, thus bringing down the algal cake resistance. Cleaning experiments after algal filtration without pre-treatment showed that physical cleaning was less effective than chemical cleaning. All four chemicals tested for membrane cleaning could reduce the cake resistance by more than 99%.

RO filtration of biologically treated textile and dyeing effluents using ozonation as a pre-treatment

2010 ◽  
Vol 62 (4) ◽  
pp. 751-758 ◽  
Author(s):  
H. Y. Wang ◽  
Y. T. Guan ◽  
T. Mizuno ◽  
H. Tsuno
Keyword(s):  
Organic Matter ◽  
Membrane Fouling ◽  
Quality Parameters ◽  
Dyeing Wastewater ◽  
Improve Performance ◽  
Membrane Cleaning ◽  
Membrane Flux ◽  
Flux Decline ◽  
Pre Treatment ◽  
Water Purity

Bench-scale experiments were conducted to investigate the application of ozonation pre-treatment for biologically treated textile and dyeing wastewater to improve performance of the RO process. Based on ozonation experiments, four specific ozone consumptions (SOC), 0, 0.3, 0.6, 4.0 mg O3/mg DOC0 were chosen for study of the effects of ozonation on the reverse osmosis (RO) process. Membrane flux was recorded. Also, the permeate water quality parameters such as TOC, conductivity were analyzed. In addition, fouled membrane cleaning was studied. The study further examined the nature and mechanisms of membrane fouling using scanning electron microscopy (SEM) and the energy dispersive X-ray spectrometer (EDS). The effect of ozonation on RO filtration was found to depend on SOC. The study revealed that significant improvement can be achieved in the efficiency of RO filtration by employing ozonation with 0.6 mg O3/mg DOC0 SOC. Although the product water purity slightly decreased, the ozonation pre-treatment showed advantages at 0.6 mg O3/mg DOC0 SOC for the following: (i) mitigation of flux decline due to membrane fouling; (ii) improvement in foulants cleanability. In addition, hypotheses were put forward to explain the reasons from the aspect of organic matter characteristics changed by ozonation, such as changing on functional groups and molecular weight of organic matter.

Effect of Two Stages Adsorption as Pre-Treatment of Natural Organic Matter Removal in Ultrafiltration Process for Peat Water Treatment

2020 ◽  
Vol 988 ◽  
pp. 114-121 ◽  
Author(s):  
Mahmud ◽  
Muthia Elma ◽  
Erdina Lulu Atika Rampun ◽  
Aulia Rahma ◽  
Amalia Enggar Pratiwi ◽  
...  
Keyword(s):  
Organic Matter ◽  
Natural Organic Matter ◽  
Membrane Fouling ◽  
Optimum Dose ◽  
Operating Pressure ◽  
Filtration Process ◽  
Dead End ◽  
Ultra Filtration ◽  
Pre Treatment ◽  
Two Stages

Natural Organic Matter (NOM) content in peat water is a major problem of membrane fouling in ultrafiltration (UF). For that, two stages adsorption as pre-treatment was employed to minimize the membrane fouling of NOM content. This research was carried out to investigate the effect of two stages adsorption on ultrafiltration performance for NOM removal that remains in peat water. This method was using powdered activated carbon (PAC) dosage of 80, 160, 240, 320, 400, 480, 560, 640, 720, 800, 880 dan 960 mg.L-1. Then, Polysulfone (Psf) material was employed for Ultra filtration process. Membrane was applied in a dead-end mode with various operating pressure (1; 1.5; 2; 2.5; 3 bar). As a results, the optimum dose of PAC was 800 mg L-1 with dosage ratio of 3/4:1/4. Two stages adsorption-UF PSf provided the range from 86.9 to 92.8% of KMnO4 and 74.1-88.1% of UV254. For the experimental condition of 3 bar, the highest flux was achieved up to 39.919 L h-1.m-2.

scholarly journals The impact of anionic polyacrylamide (APAM) on ultrafiltration efficiency in flocculation-ultrafiltration process

2017 ◽  
Vol 75 (8) ◽  
pp. 1982-1989 ◽  
Author(s):  
Ruijun Zhang ◽  
Shengnan Yuan ◽  
Wenxin Shi ◽  
Cong Ma ◽  
Zhiqiang Zhang ◽  
...  
Keyword(s):  
Membrane Fouling ◽  
Aluminium Chloride ◽  
Optimal Dosage ◽  
Cleaning Efficiency ◽  
Chemical Cleaning ◽  
Membrane Cleaning ◽  
Effluent Quality ◽  
Adsorption Sites ◽  
The Impact ◽  
Anionic Polyacrylamide

With the purpose of improving the ultrafiltration (UF) efficiency, anionic polyacrylamide (APAM) has been used as a coagulant aid in the flocculation-UF process. In this study, the impact of APAM on UF efficiency has been investigated with regard to membrane fouling, membrane cleaning and effluent quality. The results indicated that the optimal dosage of APAM had positive impacts on membrane fouling control, membrane cleaning and effluent quality. According to the flux decline curve, scanning electron microscopy and contact angle characterization, the optimal dosage of APAM was determined to be 0.1 mg/L coupled with 2 mg/L (as Al3+) poly-aluminium chloride. Under this optimal condition, membrane fouling can be mitigated because of the formation of a porous and hydrophilic fouling layer. APAM in the fouling layer can improve the chemical cleaning efficiency of 0.5% NaOH due to the disintegration of the fouling layer when APAM is dissolved under strong alkaline conditions. Furthermore, with the addition of APAM in the flocculation-UF process, more active adsorption sites can be formed in the flocs as well as the membrane fouling layer, thus more antipyrine molecules in the raw water can be adsorbed and removed in the flocculation-UF process.

Performance and membrane foulant in the pilot operation of a novel biofilm-membrane reactor

2002 ◽  
Vol 2 (2) ◽  
pp. 177-183
Author(s):  
K. Kimura ◽  
Y. Watanabe
Keyword(s):  
Membrane Fouling ◽  
Membrane Reactor ◽  
Pilot Scale ◽  
Ammonia Nitrogen ◽  
Manganese Concentration ◽  
Membrane Cleaning ◽  
Chemical Washing ◽  
Pre Treatment ◽  
Solid Liquid ◽  
Solid Liquid Separation

We have developed a novel biofilm-membrane reactor (BMR) in which a nitrifying biofilm is fixed on the surface of a rotating membrane disk. With this reactor, both strict solid-liquid separation and oxidation of ammonia nitrogen can be simultaneously performed. Based on the results obtained in previous bench-scale experiments, a pilot-scale study was conducted using river water at a water purification plant. The results obtained in the pilot study can be summarized as follows. (1) By implementation of pre-treatment (coagulation and sedimentation) and simple membrane cleaning (sponge cleaning), the filter run could be continued for 17 months without any chemical washing. (2) Sufficient nitrification was observed when water temperature was high. Deterioration in nitrification efficiency during winter was reduced by the addition of phosphorus. (3) In addition to nitrification, biological oxidation of AOC and manganese can be expected with the BMR. In this study, both AOC and manganese concentration in the permeate decreased to a level less than 10 μg/L. (4) Irreversible membrane fouling, which was thought to be mainly caused by manganese, became significant as the operation period became longer.

scholarly journals Characteristics of membrane fouling by consecutive chemical cleaning in pressurized ultrafiltration as pre-treatment of seawater desalination

Desalination ◽  
2015 ◽  
Vol 369 ◽  
pp. 51-61 ◽  
Author(s):  
Yun Chul Woo ◽  
Jeong Jun Lee ◽  
Leonard D. Tijing ◽  
Ho Kyong Shon ◽  
Minwei Yao ◽  
...  
Keyword(s):  
Membrane Fouling ◽  
Seawater Desalination ◽  
Chemical Cleaning ◽  
Pre Treatment

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.

Removal of algogenic organic matter by magnetic ion exchange resin pre-treatment and its effect on fouling in ultrafiltration

2011 ◽  
Vol 11 (1) ◽  
pp. 15-22 ◽  
Author(s):  
C. Liu ◽  
W. Chen ◽  
V. M. Robert ◽  
Z. G. Han
Keyword(s):  
Organic Matter ◽  
Ion Exchange ◽  
Membrane Fouling ◽  
Exchange Resin ◽  
Ion Exchange Resin ◽  
Major Barrier ◽  
Treated Water ◽  
Fouling Control ◽  
Pre Treatment ◽  
Magnetic Ion

Natural organic matter (NOM) fouling continues to be the major barrier to efficient application of ultrafiltration (UF) in drinking water treatment. Algogenic organic matter (AOM), the main contributor to total NOM levels in raw waters characterised by elevated algae levels, is currently the subject of much investigation. In this study, the effect of AOM on fouling of ultrafiltration and the effectiveness of magnetic ion exchange resin (MIEX®) pre-treatment for AOM removal and membrane fouling control was evaluated. The results showed that, the main species of algae in raw water were Chlorella vulgaris, which accounted for 80% of total algae. AOM was predominantly hydrophilic (50% or more) with a low SUVA (1.7 Lm−1 mg−1). Coagulation alone could not remove AOM effectively (less than 20%), however, when combined with magnetic ion exchange resin pre-treatment, more than 60% of AOM was be removed; pre-treatment followed by coagulation was observed to be very effective in controlling membrane fouling by AOM. The application of magnetic ion exchange resin technology at a bed volume treatment rate (BVTR) of 800 was observed to effectively eliminate fouling of UF membrane. Careful analyses of the molecular weight (MW) distribution of AOM and UV absorbance of treated water revealed that the effectiveness in membrane fouling control was the result of the changes in AOM molecular characteristics in treated water, namely a change in MW due to the preferential removal of high molecular proteins by coagulation and magnetic ion exchange resin pre-treatment. The results demonstrate that magnetic ion exchange resin followed by coagulation might be a new membrane pre-treatment option for UF membrane fouling control.

Foulant characterization of the NF membranes with and without pretreatment of biologically treated wastewater

2005 ◽  
Vol 51 (6-7) ◽  
pp. 277-284 ◽  
Author(s):  
H.K. Shon ◽  
S. Vigneswaran ◽  
H.H. Ngo ◽  
In S. Kim ◽  
R. Ben Aim
Keyword(s):  
Organic Matter ◽  
Small Molecules ◽  
Membrane Fouling ◽  
Operating Conditions ◽  
Treated Wastewater ◽  
Treated Sewage ◽  
Pre Treatment ◽  
Treated Sewage Effluent ◽  
Selection Of

In this study, different pretreatment methods such as ferric chloride (FeCl3) flocculation and powdered activated carbon (PAC) adsorption were evaluated in terms of their capability in removing effluent organic matter (EfOM) and the characteristics of the foulants on the NF membranes. A detailed experiment was conducted with two NF membranes (NTR 729HF with MWCO 700 daltons and LF 10 with MWCO 200 daltons). With pretreatment, the concentration of organic matter on the membranes decreased to 5.671×10−3 (NTR 729HF) and 4.940×10−3 (LF 10) mg EfOM/cm2 of membrane from 6.372×10−3 (NTR 729HF) and 4.979×10−3 (LF 10) mg EfOM/cm2 of membrane. The MW of the solute fraction of biologically treated sewage effluent (BTSE) ranged from 250 daltons to about 3573 (the most important being 250–520 daltons). The weight-averaged MW values of the foulants on the NTR 729HF membrane reduced from 304 daltons without pre-treatment to 208 daltons with pretreatment. In the case of EfOM, the small molecules (MW 300 to 500 daltons) are mainly responsible for the membrane fouling. Thus, the MW distribution of organic matter in the effluent and in the foulant can be used as a representative tool to evaluate the efficiency of pretreatment and NF and in the selection of their operating conditions.

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