Integrated membrane systems incorporating coagulation, activated carbon and ultrafiltration for the removal of toxic cyanobacterial metabolites from Anabaena circinalis

2011 ◽  
Vol 63 (7) ◽  
pp. 1405-1411 ◽  
Author(s):  
M. B. Dixon ◽  
Y. Richard ◽  
L. Ho ◽  
C. W. K. Chow ◽  
B. K. O'Neill ◽  
...  
Keyword(s):  
Drinking Water ◽  
Activated Carbon ◽  
High Performance ◽  
South Australia ◽  
Membrane System ◽  
Membrane Systems ◽  
High Quality ◽  
Aluminium Sulphate ◽  
Treatment Processes ◽  
Anabaena Circinalis

The use of integrated membrane systems (a train of treatment processes incorporating one or more membranes) is increasing globally as the technology is very effective for the production of high quality drinking water. In this investigation a laboratory scale integrated membrane system (IMS) featuring coagulation, powdered activated carbon (PAC) and ultrafiltration (UF) was investigated for the removal of an Australian strain of the cyanobacteria Anabaena circinalis and the cyanotoxin it produced. Three coagulants were compared, aluminium chlorohydrate (ACH), aluminium sulphate (alum) and an engineered aluminium coagulant referred to as high performance aluminium chlorohydrate (HPAC). PAC (Acticarb PS1000) was tested to determine adsorption of extracellular saxitoxin. Removal of A. circinalis cells was 100% by UF alone and the removal of cells prior to the membrane by coagulation reduced fouling attributed to algogenic organic material. Alum was the least efficient coagulant for removal of cells while ACH and HPAC were similar. Saxitoxin removal reached a maximum of 80% using ACH and PAC. The UF-IMS was challenged using a natural bloom of A. circinalis that occurred in the Myponga Reservoir in South Australia.

scholarly journals Pilot Study on the Combination of Different Pre-Treatments with Nanofiltration for Efficiently Restraining Membrane Fouling While Providing High-Quality Drinking Water

Membranes ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 380
Author(s):  
Yan Chen ◽  
Huiping Li ◽  
Weihai Pang ◽  
Baiqin Zhou ◽  
Tian Li ◽  
...  
Keyword(s):  
Drinking Water ◽  
Activated Carbon ◽  
Membrane Fouling ◽  
Membrane Surface ◽  
Post Treatment ◽  
Size Exclusion ◽  
Transmembrane Pressure ◽  
Feed Water ◽  
High Quality ◽  
Treated Water

Nanofiltration (NF) is a promising post-treatment technology for providing high-quality drinking water. However, membrane fouling remains a challenge to long-term NF in providing high-quality drinking water. Herein, we found that coupling pre-treatments (sand filtration (SF) and ozone–biological activated carbon (O3-BAC)) and NF is a potent tactic against membrane fouling while achieving high-quality drinking water. The pilot results showed that using SF+O3-BAC pre-treated water as the feed water resulted in a lower but a slowly rising transmembrane pressure (TMP) in NF post-treatment, whereas an opposite observation was found when using SF pre-treated water as the feed water. High-performance size-exclusion chromatography (HPSEC) and three-dimensional excitation–emission matrix (3D-EEM) fluorescence spectroscopy determined that the O3-BAC process changed the characteristic of dissolved organic matter (DOM), probably by removing the DOM of lower apparent molecular weight (LMW) and decreasing the biodegradability of water. Moreover, amino acids and tyrosine-like substances which were significantly related to medium and small molecule organics were found as the key foulants to membrane fouling. In addition, the accumulation of powdered activated carbon in O3-BAC pre-treated water on the membrane surface could be the key reason protecting the NF membrane from fouling.

Ozone and UV – a tool for multi-barrier concepts in water treatment

2006 ◽  
Vol 6 (4) ◽  
pp. 17-25 ◽  
Author(s):  
A. Ried ◽  
J. Mielcke
Keyword(s):  
Drinking Water ◽  
Wastewater Treatment ◽  
Activated Carbon ◽  
Water Treatment ◽  
Biological Treatment ◽  
Municipal Wastewater ◽  
Drinking Water Treatment ◽  
Additional Treatment ◽  
Municipal Wastewater Treatment ◽  
Treatment Processes

The use of ozone and/or UV for water treatment processes is often a combination of an ozone and/or UV-step with additional treatment steps, e.g. biological treatment, flocculation, filtration and activated carbon. Therefore, it is necessary to develop an optimized combination of these different steps. This article will demonstrate the advantages presenting two examples for drinking water treatment and two examples for municipal wastewater treatment.

scholarly journals Removal of radio N-nitrosodimethylamine (NDMA) from drinking water by coagulation and Powdered Activated Carbon (PAC) adsorption

2009 ◽  
Vol 2 (1) ◽  
pp. 79-100 ◽  
Author(s):  
J. Chung ◽  
Y. Yoon ◽  
M. Kim ◽  
S.-B. Lee ◽  
H.-J. Kim ◽  
...  
Keyword(s):  
Drinking Water ◽  
Activated Carbon ◽  
Water Treatment ◽  
Background Electrolyte ◽  
Treatment Plant ◽  
Drinking Water Treatment ◽  
Powdered Activated Carbon ◽  
Individual Treatment ◽  
Solution Ph ◽  
Treatment Processes

Abstract. The presence of N-nitrosodimethylamine (NDMA) in drinking water supplies has raised concern over its removal by common drinking water treatment processes. A simple detection method based on scintillation spectroscopy has been used to quantify the concentration of 14C-labeled NDMA at various ratios of sample to scintillation liquid. Without sample pretreatment, the method detection limits are 0.91, 0.98, 1.23, and 1.45 ng/L of NDMA at scintillation intensity ratios of 10:10, 5:15, 15:5, and 2.5:17.5 (sample: scintillation liquid), respectively. The scintillation intensity in all cases is linear (R2>0.99) and is in the range of 0 to 100 ng/L of NDMA. In addition, because scintillation intensity is independent of solution pH, conductivity, and background electrolyte ion types, a separate calibration curve is unnecessary for NDMA samples at different solution conditions. Bench-scale experiments were performed to simulate individual treatment processes, which include coagulation and adsorption by powdered activated carbon (PAC), as used in a drinking water treatment plant, and biosorption, a technique used in biological treatment of waste water. The commonly used coagulation process for particulate control and biosorption is ineffective for removing NDMA (<10% by coagulation and <20% by biosorption). However, high doses of PAC may be applied to remove NDMA.

Assessment of membrane processes for taste and odour removal

2001 ◽  
Vol 1 (4) ◽  
pp. 19-24
Author(s):  
J.-M. Laîne ◽  
K. Glucina ◽  
L. Malleret ◽  
A. Bruchet ◽  
I. Baudin ◽  
...  
Keyword(s):  
Drinking Water ◽  
Activated Carbon ◽  
Reverse Osmosis ◽  
Potable Water ◽  
Powdered Activated Carbon ◽  
Air Stripping ◽  
Membrane Processes ◽  
Treatment Processes ◽  
Water Companies ◽  
Odour Removal

The occurrence of tastes and odours (T&O) in potable water is considered one of the main problems by the drinking water companies. Thus, several treatment processes have been developed over the years to control T&O, including air stripping, activated carbon and oxidation using ozone. However, little information is available in the literature on the use of membranes for T&O removal. Therefore, the objective of this paper is to present potential of membrane processes for the removal of taste and odour-causing compounds. Several membranes were tested including ultrafiltration (UF), UF combined with powdered activated carbon (PAC), nanofiltration (NF) and low pressure reverse osmosis (LP RO) membranes. Combination of UF with PAC was found to be effective for T&O control. The use of NF or LP RO is still unclear in the objective of T&O control.

scholarly journals Optimising water treatment practices for the removal of Anabaena circinalis and its associated metabolites, geosmin and saxitoxins

2009 ◽  
Vol 7 (4) ◽  
pp. 544-556 ◽  
Author(s):  
Lionel Ho ◽  
Paul Tanis-Plant ◽  
Nawal Kayal ◽  
Najwa Slyman ◽  
Gayle Newcombe
Keyword(s):  
Drinking Water ◽  
Activated Carbon ◽  
Water Treatment ◽  
Treatment Practices ◽  
Water Treatment Plants ◽  
Cyanobacterium Anabaena ◽  
Pertinent Information ◽  
Equivalent Conditions ◽  
Anabaena Circinalis

The cyanobacterium Anabaena circinalis has the ability to co-produce geosmin and saxitoxins, compounds which can compromise the quality of drinking water. This study provides pertinent information in optimising water treatment practices for the removal of geosmin and saxitoxins. In particular, it demonstrates that pre-oxidation using potassium permanganate could be applied at the head of water treatment plants without releasing intracellular geosmin and saxitoxins from A. circinalis. Furthermore, powdered activated carbon (PAC) was shown to be an effective treatment barrier for the removal of extracellular (dissolved) geosmin and saxitoxins, with similar adsorption trends of both compounds. The relative removal of the saxitoxins compared with geosmin was determined to be 0.84±0.27, which implies that saxitoxin removal with PAC can be estimated to be approximately 60 to 100% of the removal of geosmin under equivalent conditions. Chlorine was shown to be effective for the oxidation of the saxitoxins with CT values of approximately 30 mg min l−1 required for greater than 90% destruction of the saxitoxins.

scholarly journals Combination of low-pressure UF membranes with conventional water treatment systems

2017 ◽  
Vol 19 (4) ◽  
pp. 584-591
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Water Treatment ◽  
Low Pressure ◽  
Drinking Water Quality ◽  
Membrane Systems ◽  
System Combination ◽  
Treatment Processes ◽  
Water Treatment Plants ◽  
Uf Membranes

The purpose of the study was to improve drinking water quality of conventional treatment processes by combining with UF-membrane systems. Performances of two membrane systems were evaluated in two different full-scale conventional water treatment plants in Istanbul. Low-pressure UF membranes were combined after settling and filtration units of Büyükçekmece and Emirli water treatment plants. Low-pressure UF systems were operated under vacuum and pressure conditions. The experimental results indicated that combining UF systems enhanced drinking water quality with respect to turbidity, TOC and UV254 removal. In all cases, vacuum-driven UF membranes provided higher treatment performance and low energy consumption comparing to pressure-driven system. Combination with UF membranes also reduced disinfection by-products.

scholarly journals Development of a predictive model to determine micropollutant removal using granular activated carbon

2009 ◽  
Vol 2 (2) ◽  
pp. 57-62 ◽  
Author(s):  
D. J. de Ridder ◽  
M. McConville ◽  
A. R. D. Verliefde ◽  
L. T. J. van der Aa ◽  
S. G. J. Heijman ◽  
...  
Keyword(s):  
Drinking Water ◽  
Activated Carbon ◽  
Input Parameter ◽  
Drinking Water Treatment ◽  
Water Sources ◽  
Organic Micropollutants ◽  
Ultrapure Water ◽  
Treatment Processes ◽  
Micropollutant Removal ◽  
Low Concentrations

Abstract. The occurrence of organic micropollutants in drinking water and its sources has opened up a field of study related to monitoring concentration levels in water sources, evaluating their toxicity and estimating their removal in drinking water treatment processes. Because a large number of organic micropollutants is currently present (although in relatively low concentrations) in drinking water sources, a method should be developed to select which micropollutants has to be evaluated with priority. In this paper, a screening model is presented that can predict solute removal by activated carbon, in ultrapure water and in natural water. Solute removal prediction is based on a combination of solute hydrophobicity (expressed as log D, the pH corrected log Kow), solute charge and the carbon dose. Solute molecular weight was also considered as model input parameter, but this solute property appeared to relate insufficiently to solute removal. Removal of negatively charged solutes by preloaded activated carbon was reduced while the removal of positively charged solutes was increased, compared with freshly regenerated activated carbon. Differences in charged solute removal by freshly regenerated activated carbon were small, indicating that charge interactions are an important mechanism in adsorption onto preloaded carbon. The predicted solute removal was within 20 removal-% deviation of experimentally measured values for most solutes.

Applications of flat sheet ceramic membrane for surface water and seawater treatments – introduction of performance in large-scale drinking water plant and seawater pretreatment pilot system in Singapore

2019 ◽  
Vol 14 (2) ◽  
pp. 289-296 ◽  
Author(s):  
H. Noguchi ◽  
M. H. Oo ◽  
T. Niwa ◽  
E. Fong ◽  
R. Yin ◽  
...  
Keyword(s):  
Drinking Water ◽  
Large Scale ◽  
Ceramic Membrane ◽  
Hollow Fiber Membrane ◽  
Membrane Integrity ◽  
Membrane System ◽  
Ceramic Membranes ◽  
High Quality ◽  
Flat Sheet ◽  
Quality Water

Abstract PUB, Singapore's National Water Agency, has been using polymeric UF membrane in drinking water plants to produce high quality water whilst requiring a smaller footprint. Submerged polymeric hollow-fiber membrane has been used since 2003 in Chestnut Avenue Water Works (CAWW). PUB decided to use submerged-type ceramic membranes for enhancement of production capacity at CAWW. The flat-sheet ceramic membrane system was retrofitted into two spare, empty tanks with a combined design capacity of 36,400 m3/d. The system has been successfully put into operation, running at a net flux of 160 L/m2-h (LMH) since June 2017. Membrane integrity testing is automatically carried out once a week to ensure the membranes' integrity. Stable filtrate quality has been achieved with a low turbidity of 0.018 NTU on average. Pretreatment for seawater desalination is another application in which a ceramic membrane system can be operated at higher flux compared to that for polymeric membranes. A pilot scale system was installed at PUB R&D facility in Tuas to investigate sustainable operating flux and permeate quality. FeCl3 was used as a coagulant before ceramic filtration, with a dosage of 4–6 mg/L. It was shown that sustainable flux can be 181–249 LMH in seawater treatment system with flat sheet ceramic membranes. The silt density index and turbidity of permeate were 1.6–2.2 and 0.04–0.10 NTU, respectively, which indicates that the system can produce high quality water for feed of reverse osmosis systems.

Efficiency of membrane processes for taste and odor removal

2005 ◽  
Vol 51 (6-7) ◽  
pp. 257-265 ◽  
Author(s):  
A. Bruchet ◽  
J.M. Laîné
Keyword(s):  
Drinking Water ◽  
Activated Carbon ◽  
Reverse Osmosis ◽  
Powdered Activated Carbon ◽  
Air Stripping ◽  
Membrane Processes ◽  
Treatment Processes ◽  
Taste And Odor ◽  
Odor Removal ◽  
Water Companies

The occurrence of tastes and odors (T&O) in drinking water is considered as one of the main problems by the drinking water companies. Thus, several treatment processes were developed over the years to control T&O including air stripping, activated carbon and oxidation using ozone. However, little information is available in the literature on the use of membranes for T&O removal. Therefore, the objectives of this paper are to present potential of membrane processes for removal of taste and odor causing compounds. Several membranes were tested including ultrafiltration (UF), UF combined with powdered activated carbon (PAC), nanofiltration (NF) and low pressure reverse osmosis (LP RO) membranes. The results of this study indicate that the combination of UF with PAC is effective for T&O control whereas the benefit of NF and LP RO remains unclear for T&O control.

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