Removal of natural organic matter (nom) from drinking water supplies by ozone-biofiltration

Increased concentrations of natural organic matter (NOM), a complex mixture of organic substances found in most surface waters, have recently emerged as a substantial environmental issue. NOM has a significant variety of molecular and chemical properties, which in combination with its varying concentrations both geographically and seasonally, introduce the opportunity for an array of interactions with the environment. Due to an observable increase in amounts of NOM in water treatment supply sources, an improved effort to remove naturally-occurring organics from drinking water supplies, as well as from municipal wastewater effluents, is required to continue the development of highly efficient and versatile water treatment technologies. Photocatalysis has received increasing interest from around the world, especially during the last decade, as several investigated processes have been regularly reported to be amongst the best performing water treatment technologies to remove NOM from drinking water supplies and mitigate the formation of disinfection by products. Consequently, this overview highlights recent research and developments on the application of photocatalysis to degrade NOM by means of TiO2-based heterogeneous and homogeneous photocatalysts. Analytical techniques to quantify NOM in water and hybrid photocatalytic processes are also reviewed and discussed.

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Concentration and Diversity of UnculturedLegionellaspp. in Two Unchlorinated Drinking Water Supplies with Different Concentrations of Natural Organic Matter

Applied and Environmental Microbiology ◽

10.1128/aem.01215-10 ◽

2010 ◽

Vol 77 (2) ◽

pp. 634-641 ◽

Cited By ~ 61

Author(s):

Bart A. Wullings ◽

Geo Bakker ◽

Dick van der Kooij

Keyword(s):

Drinking Water ◽

Organic Matter ◽

Natural Organic Matter ◽

Distribution Systems ◽

Sequence Similarity ◽

Treatment Plant ◽

Branch Length ◽

Culture Method ◽

Water Supplies ◽

Total Species Richness

ABSTRACTTwo unchlorinated drinking water supplies were investigated to assess the potential of water treatment and distribution systems to support the growth ofLegionellaspp. The treatment plant for supply A distributed treated groundwater with a low concentration (<0.5 ppm of C) of natural organic matter (NOM), and the treatment plant for supply B distributed treated groundwater with a high NOM concentration (8 ppm of C). In both supplies, the water temperature ranged from about 10°C after treatment to 18°C during distribution. The concentrations ofLegionellaspp. in distributed water, analyzed with quantitative PCR (Q-PCR), averaged 2.9 (± 1.9) × 102cells liter−1in supply A and 2.5 (± 1.6) × 103cells liter−1in supply B. NoLegionellawas observed with the culture method. A total of 346 clones (96 operational taxonomical units [OTUs] with ≥97% sequence similarity) were retrieved from water and biofilms of supply A and 251 (43 OTUs) from supply B. The estimation of the average value of total species richness (Chao1) in supply A (153) was clearly higher than that for supply B (58). In each supply, about 77% of the sequences showed <97% similarity to described species. Sequences related toL. pneumophilawere only incidentally observed. TheLegionellapopulations of the two supplies are divided into two distinct clusters based on distances in the phylogenetic tree as fractions of the branch length. Thus, a large variety of mostly yet-undescribedLegionellaspp. proliferates in unchlorinated water supplies at temperatures below 18°C. The lowest concentration and greatest diversity were observed in the supply with the low NOM concentration.

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Modification of Bael fruit shell and its application towards Natural organic matter removal with special reference to predictive modeling and control of THMs in drinking water supplies

Environmental Technology & Innovation ◽

10.1016/j.eti.2020.100666 ◽

2020 ◽

Vol 18 ◽

pp. 100666 ◽

Cited By ~ 1

Author(s):

Jaydev Kumar Mahato ◽

Sunil Kumar Gupta

Keyword(s):

Drinking Water ◽

Organic Matter ◽

Special Reference ◽

Natural Organic Matter ◽

Predictive Modeling ◽

Water Supplies ◽

Organic Matter Removal ◽

Modeling And Control ◽

And Control

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Coagulation/flocculation/ultrafiltration for natural organic matter removal in drinking water production

Water Science & Technology Water Supply ◽

10.2166/ws.2004.0111 ◽

2004 ◽

Vol 4 (5-6) ◽

pp. 215-222 ◽

Cited By ~ 2

Author(s):

A.R. Costa ◽

M.N. de Pinho

Keyword(s):

Drinking Water ◽

Organic Matter ◽

Natural Organic Matter ◽

Membrane Fouling ◽

Membrane Filtration ◽

Membrane Surface ◽

Water Production ◽

Cellulose Acetate Membranes ◽

Wide Range ◽

Drinking Water Production

Membrane fouling by natural organic matter (NOM), namely by humic substances (HS), is a major problem in water treatment for drinking water production using membrane processes. Membrane fouling is dependent on membrane morphology like pore size and on water characteristics namely NOM nature. This work addresses the evaluation of the efficiency of ultrafiltration (UF) and Coagulation/Flocculation/UF performance in terms of permeation fluxes and HS removal, of the water from Tagus River (Valada). The operation of coagulation with chitosan was evaluated as a pretreatment for minimization of membrane fouling. UF experiments were carried out in flat cells of 13.2×10−4 m2 of membrane surface area and at transmembrane pressures from 1 to 4 bar. Five cellulose acetate membranes were laboratory made to cover a wide range of molecular weight cut-off (MWCO): 2,300, 11,000, 28,000, 60,000 and 75,000 Da. Severe fouling is observed for the membranes with the highest cut-off. In the permeation experiments of raw water, coagulation prior to membrane filtration led to a significant improvement of the permeation performance of the membranes with the highest MWCO due to the particles and colloidal matter removal.

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