Water Treatment Considerations–Aquatic Humus

1983 ◽  
Vol 15 (S2) ◽  
pp. 95-101 ◽  
Author(s):  
E T Gjessing
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Humic Substances ◽  
Health Effects ◽  
Surface Waters ◽  
Cold Climate ◽  
Treatment Processes ◽  
Aquatic Humus ◽  
Treatment Considerations

For several reasons the surface waters in cold climate areas are coloured due to humic substances. There are two major objections against humus in drinking water, the first is concerned with aesthetical and practical problems and the second is due to indirect negative health effects. There are essentially three different methods in use today for the removal or reduction of humus colour in water: (1) Addition of chemicals with the intention of reducing the “solubility”, (2) Addition of chemicals in order to bleach or mineralize the humus, and (3) Filtration with the intention of removal of coloured particles and some of the “soluble” colour. The treatment processes are discussed.

scholarly journals The Role of Catalytic Ozonation Processes on the Elimination of DBPs and Their Precursors in Drinking Water Treatment

Catalysts ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 521
Author(s):  
Fernando J. Beltrán ◽  
Ana Rey ◽  
Olga Gimeno
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Humic Substances ◽  
Hypochlorous Acid ◽  
Drinking Water Treatment ◽  
Disinfection Byproducts ◽  
Catalytic Ozonation ◽  
Operating Conditions ◽  
Halogen Compounds ◽  
Radiation Sources

Formation of disinfection byproducts (DBPs) in drinking water treatment (DWT) as a result of pathogen removal has always been an issue of special attention in the preparation of safe water. DBPs are formed by the action of oxidant-disinfectant chemicals, mainly chlorine derivatives (chlorine, hypochlorous acid, chloramines, etc.), that react with natural organic matter (NOM), mainly humic substances. DBPs are usually refractory to oxidation, mainly due to the presence of halogen compounds so that advanced oxidation processes (AOPs) are a recommended option to deal with their removal. In this work, the application of catalytic ozonation processes (with and without the simultaneous presence of radiation), moderately recent AOPs, for the removal of humic substances (NOM), also called DBPs precursors, and DBPs themselves is reviewed. First, a short history about the use of disinfectants in DWT, DBPs formation discovery and alternative oxidants used is presented. Then, sections are dedicated to conventional AOPs applied to remove DBPs and their precursors to finalize with the description of principal research achievements found in the literature about application of catalytic ozonation processes. In this sense, aspects such as operating conditions, reactors used, radiation sources applied in their case, kinetics and mechanisms are reviewed.

scholarly journals Comprehensive Analysis of Jet Flocculator in Square and Circular Basin

2020 ◽  
Vol 8 (6) ◽  
pp. 5038-5041
Keyword(s):  
Experimental Investigation ◽  
Drinking Water ◽  
Water Treatment ◽  
Flow Pattern ◽  
Comprehensive Analysis ◽  
Jet Mixing ◽  
Treatment Processes ◽  
Geometrical Shapes ◽  
Flocculation Process ◽  
Comprehensive Study

The demand for better quality drinking water gives inspiration for advancement in the functioning of water treatment processes. Jet mixing technology, widely adopted in Flocculation process is unique due to its advantages over mechanical stirrer or vanes. Jet flocculator take primacy, as it do not have any moving parts inside the reactor. The present experimental investigation focuses on the examination of jets in flocculation. Comprehensive study of various parameters such as nozzle diameter, angle of inclination, flow pattern and jet position in two geometrical shapes of flocculation chamber: Square and Circular. Effect of tank shapes on flocculation process is analysed and compared.

Is biological treatment a viable alternative for micropollutant removal in drinking water treatment processes?

2013 ◽  
Vol 47 (16) ◽  
pp. 5955-5976 ◽  
Author(s):  
Jessica Benner ◽  
Damian E. Helbling ◽  
Hans-Peter E. Kohler ◽  
Janneke Wittebol ◽  
Elena Kaiser ◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Biological Treatment ◽  
Drinking Water Treatment ◽  
Viable Alternative ◽  
Treatment Processes ◽  
Micropollutant Removal

Microcystin class of toxins: health effects and safety of drinking water supplies

1994 ◽  
Vol 2 (2) ◽  
pp. 167-186 ◽  
Author(s):  
T. W. Lambert ◽  
C. F. B. Holmes ◽  
S. E. Hrudey
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Health Risk ◽  
Health Effects ◽  
Tumor Promoter ◽  
Water Supplies ◽  
Blue Green Algae ◽  
Adverse Health Effects ◽  
Human Illness ◽  
Safety Of Drinking Water

The microcystins are produced by several species of common planktonic cyanobacteria found in surface waters, but their biological function remains unknown. The microcystins have been shown to be extremely potent hepatotoxins in a variety of experimental animals and they are lethal at low doses. Microcystin-LR, one of over 40 microcystin analogues, has also been shown to be a potent tumor promoter. The toxic effects of the microcystins have been attributed to the inhibition of protein phosphatases. This inhibition causes collapse of the cytoskeleton and interferes with a general signal transduction mechanism in cells. The presence of toxic cyanobacteria in surface water has been documented in all parts of the world. The microcystins have been related to a few incidents of human illness and several incidents of animal poisoning in Canada, United States, Australia, Europe, and Africa. Therefore, exposure to the microcystins is a potentially significant health risk and toxin removal from drinking water is becoming a concern worldwide. Conventional water treatment processes (coagulation/sedimentation, chlorination) have generally proven ineffective at removing microcystin toxins from drinking water. Activated carbon, ozone, and free chlorine have been effective in removing microcystins below detectable concentrations in laboratory experiments. Considering these factors, the occurrence of microcystins in drinking water supplies deserves serious attention to insure that adverse health effects are prevented.Key words: microcystins, hepatotoxins, cyanobacteria, blue-green algae, water treatment, health risk.

scholarly journals Improving chemical cleaning of fouled membranes in a drinking water treatment plant

2019 ◽  
Vol 19 (8) ◽  
pp. 2330-2337
Author(s):  
Susumu Hasegawa ◽  
Yasuhiro Tanaka ◽  
Naokazu Wake ◽  
Ryosuke Takagi ◽  
Hideto Matsuyama
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Humic Substances ◽  
Sodium Hypochlorite ◽  
Membrane Fouling ◽  
Treatment Plant ◽  
Drinking Water Treatment ◽  
Water Treatment Plant ◽  
Chemical Cleaning ◽  
Water Treatment Plants

Abstract Recently, membrane filtration systems have become increasingly common in drinking water treatment plants. In this industry, preventing membrane fouling is of utmost importance. Many studies on the relationship between raw water components and membrane fouling have been performed in laboratory conditions. However, very few studies have analyzed the components of foulants on the fouled membrane as operated in actual drinking water treatment plants. By analyzing these components in plant-conditions, membrane fouling will be more effectively prevented. In this study, we analyzed the components of foulants extracted with 0.1 N NaOH from a fouled membrane operated in a drinking water treatment plant in Japan. Our analysis revealed that the main foulants were humic substances. In order to dissolve the accumulated humic substances, additional chemical cleaning was attempted with 500 ppm sodium hypochlorite. As a result, it was found that humic substances were dissolved and filtration resistance significantly decreased. Additionally, the removal of inorganic foulants was also greater after chemical cleaning with 500 ppm sodium hypochlorite, as inorganic foulants trapped within humic substances were released to the membrane surface as hydroxides by the additional sodium hypochlorite cleaning and were dissolved by the periodic citric acid cleaning.

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