Extra-Cellular Polysaccharides, Soluble Microbial Products, and Natural Organic Matter Impact on Nanofiltration Membranes Flux Decline

2007 ◽  
Vol 41 (7) ◽  
pp. 2491-2497 ◽  
Author(s):  
A. Cristina Fonseca ◽  
R. Scott Summers ◽  
Alan R. Greenberg ◽  
Mark T. Hernandez
Keyword(s):  
Organic Matter ◽  
Natural Organic Matter ◽  
Soluble Microbial Products ◽  
Nanofiltration Membranes ◽  
Flux Decline ◽  
Microbial Products

Direct coagulation pretreatment in nanofiltration of waters rich in organic matter and calcium

2001 ◽  
Vol 1 (4) ◽  
pp. 25-33
Author(s):  
A. I. Schäfer ◽  
A.G. Fane ◽  
T.D. Waite
Keyword(s):  
Organic Matter ◽  
Natural Organic Matter ◽  
Surface Waters ◽  
Process Efficiency ◽  
Nanofiltration Membranes ◽  
Multivalent Ions ◽  
Flux Decline ◽  
Calcium Complexes ◽  
The Impact ◽  
Significant Flux

Nanofiltration (NF) can remove natural organic matter (NOM) and multivalent ions from surface waters. Large hydrophobic organics and calcium ions are responsible for irreversible fouling of nanofiltration membranes and thus a decrease of process efficiency and increase in cleaning requirements. Fouling due to the precipitation of organic-calcium complexes and the impact of colloids and coagulant (FeCl3) on the precipitation of these species was investigated. Coagulation in solution (as opposed to in the boundary layer) did not cause significant flux decline and was able to prevent irreversible fouling under conditions which were previously determined as detrimental. The rejection was varied if a strongly charged solid was deposited on the membrane.

Natural organic matter removal and flux decline with charged ultrafiltration and nanofiltration membranes

2011 ◽  
Vol 376 (1-2) ◽  
pp. 179-187 ◽  
Author(s):  
Hongchen Song ◽  
Jiahui Shao ◽  
Yiliang He ◽  
Juan Hou ◽  
Wenpo Chao
Keyword(s):  
Organic Matter ◽  
Natural Organic Matter ◽  
Nanofiltration Membranes ◽  
Organic Matter Removal ◽  
Flux Decline

Effect of silver in severely nitrified chloraminated bulk waters

2012 ◽  
Vol 12 (4) ◽  
pp. 415-421 ◽  
Author(s):  
K. C. Bal Krishna ◽  
Arumugam Sathasivan
Keyword(s):  
Organic Matter ◽  
Natural Organic Matter ◽  
Control Strategy ◽  
Ph Value ◽  
Conventional Approach ◽  
Water Utilities ◽  
Soluble Microbial Products ◽  
Traditional Belief ◽  
Microbial Products ◽  
By Products

Chloramine has been widely used in many water utilities as a secondary disinfectant because of increased concern over disinfection by-products (DBPs) formation. However, its popularity has been affected due to microbial acceleration, which is traditionally believed to be by nitrifying organisms or their products such as nitrite and pH value which change substantially under nitrifying conditions. With the traditional belief in mind, the conventional approach to solve ‘chloramine decay’ was aimed at killing or flushing out nitrifiers. We have recently shown that either soluble microbial products (SMPs) released by microbes or changes in natural organic matter (NOM) characteristics under nitrified conditions could be responsible for the acceleration. With this new insight, a new control strategy was attempted by dosing silver at a concentration of 0.1 mg-Ag/L to the nitrified bulk waters obtained in a laboratory scale system. Accelerated chemical and microbial chloramine losses were significantly reduced after the addition of silver. These results are very promising for future applications.

Investigation of membrane fouling by synthetic and natural particles

2004 ◽  
Vol 50 (12) ◽  
pp. 279-285 ◽  
Author(s):  
J.H. Kweon ◽  
D.F. Lawler
Keyword(s):  
Organic Matter ◽  
Natural Organic Matter ◽  
Membrane Fouling ◽  
Membrane Surface ◽  
Research Articles ◽  
Clay Material ◽  
Dramatic Effect ◽  
Flux Decline ◽  
Scanning Electron

The biggest impediment for applying membrane processes is fouling that comes from mass flux (such as particle and organic matter) to the membrane surface and its pores. Numerous research articles have indicated that either particles or natural organic matter (NOM) has been the most detrimental foulant. Therefore, the role of particles in membrane fouling was investigated with two synthetic waters (having either particles alone or particles with simple organic matter) and a natural water. Membrane fouling was evaluated with flux decline behavior and direct images from scanning electron microscopy. The results showed that the combined fouling by kaolin and dextran (a simple organic compound selected as a surrogate for NOM) showed no difference from the fouling with only the organic matter. The similarity might stem from the fact that dextran (i.e., polysaccharide) has no ability to be adsorbed on the clay material, so that the polysaccharide behaves the same with respect to the membrane with or without clay material being present. In contrast to kaolin, the natural particles showed a dramatic effect on membrane fouling.

scholarly journals Evaluation of DBPs formation from SMPs exposed to chlorine, chloramine and ozone

2016 ◽  
Vol 15 (2) ◽  
pp. 185-195 ◽  
Author(s):  
Beibei Zhang ◽  
Qiming Xian ◽  
Jian Lu ◽  
Tingting Gong ◽  
Aimin Li ◽  
...  
Keyword(s):  
Natural Organic Matter ◽  
Chlorinated Solvents ◽  
Good Alternative ◽  
Haloacetic Acids ◽  
Soluble Microbial Products ◽  
Key Factors ◽  
Factors Affecting ◽  
Important Group ◽  
Microbial Products ◽  
By Products

Soluble microbial products (SMPs) are an important group of components in wastewater effluents. In this study, the formation of disinfection by-products (DBPs), including trihalomethanes (THMs), haloacetic acids (HAAs), chlorinated solvents (CSs), haloketones (HKs), haloacetonitriles (HANs) and trichloronitromethane (TCNM) (chloropicrin), from SMPs during chlorination, chloramination and ozonation was investigated. More carbonaceous DBPs (C-DBPs: THMs, HAAs, CSs and HKs) and nitrogenous DBPs (N-DBPs: HANs and TCNM) were formed in chlorination than chloramination. More dichloroacetic and N-DBPs, and higher DBP formation potential were generated by SMPs than by natural organic matter. The results also show that disinfection factors, including temperature, pH, disinfectant dose, reaction time and bromide level significantly affected the formation of DBPs from SMPs. Additionally, the bromine incorporation factor indicates that chloramination may be a good alternative to chlorination in reducing the formation of Br-DBPs from SMPs. Bromide level and pH were the key factors affecting the formation of DBPs in both chlorination and chloramination.

scholarly journals Using Molecular Weight-Based Fluorescent Detector to Characterize Dissolved EffluentOrganic Matter in Oxidation Ditch with Algae

2021 ◽  
Author(s):  
Euis Nurul Hidayah ◽  
Okik Hendriyanto Cahyonugroho ◽  
Elita Nurfitriyani Sulistyo ◽  
Nieke Karnangingroem
Keyword(s):  
Molecular Weight ◽  
Organic Matter ◽  
Humic Acid ◽  
Fulvic Acid ◽  
Average Molecular Weight ◽  
Soluble Microbial Products ◽  
Oxidation Ditch ◽  
Effluent Organic Matter ◽  
Wastewater Quality ◽  
Microbial Products

Abstract Implementation microalgae has been considered for enhancing effluent wastewater quality. However, algae can cause environmental issues due to algae released extracellular organic matter, algal organic matter, instead of bacteria-derived organic matter in the biological process. The objectives of this study are to investigate the characteristics of dissolved effluent organic matter as algal-derived organic and bacteria-derived organic during the oxidation ditch process. Experiments were conducted in the oxidation ditch without algae, with Spirulina platensis and Chlorella vulgaris. The results showed dissolved effluent organic matter increased into higher dissolved organic carbon, more aromatic and hydrophobic than that before treatment. Fluorescence spectroscopy identified two component, namely aromatic protein-like at excitation/emission 230/345 nm and soluble microbial products-like at 320/345 nm after treatment, instead of fulvic acid-like at 230/420 nm and humic acid-like at 320/420 nm in raw wastewater. Fractionation of dissolved organic fluorescence based on average molecular weight cut-offs (MWCOs) has obtained that fractions aromatic protein-like, fulvic acid-like, humic acid-like, and soluble microbial products-like has respectively a high MWCOs 50,000 Da, a high to low MWCOs <1650 Da, medium MWCOs 1650 Da to low MWCOs. Biological oxidation ditch under symbiosis algal-bacteria generated humic acid-like and fulvic acid-like with a higher MWCOs than oxidation without algal. The quality and quantity of dissolved effluent organic matter in oxidation ditch algal reactor has been significant affected by algal-bacteria symbiotic.

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