A mini review of preoxidation to improve coagulation

Xie, Pengchao; Chen, Yiqun; Ma, Jun; Zhang, Xiang; Zou, Jing; Wang, Zongping

doi:10.1016/j.chemosphere.2016.04.003

Cited by 143 publications

(44 citation statements)

References 130 publications

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“…if not optimized. Pre-oxidation is vital for improving coagulation because it can alter the surface of algal and cyanobacterial cells and change the zeta potential which leads to improved coagulation as detailed in Henderson et al, 2008;Xie et al, 2016;.…”

Section: Accepted Manuscriptmentioning

confidence: 99%

The effect of water treatment unit processes on cyanobacterial trichome integrity

Pestana

Neto

Lawton

et al. 2019

Science of The Total Environment

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Many toxic and/or noxious cyanobacteria appear in nature with a filamentous, stacked cell arrangement called trichomes. Although water treatment can be optimized to keep cyanobacterial cells intact and avoid the release of toxic and/or noxious compounds, many physical and chemical stresses encountered during the treatment process may result in trichome truncation, decreasing treatment efficiency by allowing single cells or short trichomes to reach the product water. This makes it possible for harmful/noxious compounds as well as organic matter to enter the distribution system. Investigations in a pilot and three full-scale water treatment plants were carried out in order to elucidate the degree of trichome truncation across different unit processes. It was found that genera (Pseudanabaena, Planktolyngbya) with short trichomes (<10-12 cells per trichome), are hardly affected by the unit processes (loss of one to four cells respectively), while genera (Planktothrix, Geitlerinema, Dolichospermum) with longer trichomes (30+ cells per trichome) suffer from high degrees of truncation (up to 63, 30, and 56 cells per trichome respectively). The presence of a rigid sheath and/or mucilaginous layer appears to offer some protection from truncation. It was observed that certain unit processes alter the sensitivity or resilience of trichomes to disruption by physical stress. Some genera (Planktothrix, Geitlerinema) were sensitive to pre-oxidation making them more susceptible to shear stress, while Dolichospermum sp. appears more robust after pre-oxidation. While the potential of toxicogenic genera breaking through into the product water is a real danger, in the current study no toxicogenic cyanobacteria were observed.

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Section: Accepted Manuscriptmentioning

confidence: 99%

The effect of water treatment unit processes on cyanobacterial trichome integrity

Pestana

Neto

Lawton

et al. 2019

Science of The Total Environment

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“…Many studies have also demonstrated that preoxidation can enhance the removal of algal and cyanobacterial cells in coagulation/flocculation/filtration. Xie et al () have compiled a recent review of preoxidation technology.…”

Section: Treatment Processesmentioning

confidence: 99%

A Cyanotoxin Primer for Drinking Water Professionals

Westrick

Szlag²

2018

Journal AWWA

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Cyanobacteria and cyanotoxins became an emerging issue for the drinking water industry in 1998 by appearing in the first US Environmental Protection Agency drinking water Contaminant Candidate List (CCL 1). Before CCL, cyanotoxin contaminants did not fit into the two prevailing paradigms: synthetic chemicals and pathogens. Cyanotoxins added a new paradigm: natural chemical toxins. Driven by anthropogenic influences, nutrient loading, and climate change, cyanobacterial blooms are increasing in frequency and distribution. To efficiently produce potable water from a source impacted by a toxic cyanobacterial bloom, drinking water practitioners need to take a multidisciplinary approach. Bloom dynamics (biology), surrogate and analytical methods (chemistry), inactivation/removal of intra-and extracellular toxins and multibarrier treatment (engineering), and risk management (public health) must all be part of a comprehensive management strategy. This article provides a holistic primer for water professionals on cyanotoxin treatment and management using pertinent literature, technical sources, case studies, and experience.

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“…The DBPs formation could be prevented through removing NOM before the disinfection process. A number of characterizations of organic matter have been developed (Matilainen et al, 2011;Tran et al, 2015;Sillanpää et al, 2015) along with the treatment processes to remove NOM, such as pre-oxidation, coagulation, ion exchange, adsorption, membrane process, and their combinations (Reckhow and Singer, 2011;Lai et al, 2015;Xie et al, 2016). Coagulation is the most common treatment for the removal if organic compounds, even pre-oxidation has been applied as pretreatment to improve coagulation performance ( In order to know the fate of organic matters changing after treatment and to reveal the formation mechanism of DBPs, model compounds have been applied as NOM surrogates (Liang and Singer, 2003;Bond et al, 2009).…”

Section: Introductionmentioning

confidence: 99%

Assessment of Organic Fraction Based on Its Molecular Weight and Disinfection by-Product Formation Through Different Coagulant

Hidayah¹,

Cahyonugroho²

2019

J. Ecol. Eng.

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Chlorination is the most common disinfection method used in the drinking water production. Reactivity of chlorine with organic molecules could generate disinfection by-product (DBPs), which are harmful to the human health. Natural organic matter (NOM) is a complex mixture of chemicals existing in source water. Because of its complexity, it is conjectured that formation of many different DBPs can arise from the reaction of organic matter and a chemical disinfectant. This study used model compounds as NOM surrogates in order to reveal the specific organic fraction and DBPs formation potential removed by different coagulants. Model compounds, as an artificial sample, were made from a mixture of Suwannee River Humic Acid (SRHA), Suwannee River Fulvic Acid (SRFA), Bovine Serum Albumin (BSA), Alginic Acid (AA). Alum and FeCl 3 were used as coagulants. The samples were analyzed for organic parameters, such as total organic carbon (TOC), ultraviolet at 254 nm wavelength (UV 254), specific UV absorbance (SUVA), and organic fractionated by high performance size exclusion chromatograph with organic carbon detector (HPSEC-OCD). The concentration of trihalomethanes (THMs) and haloacetic acids (HAAs) was measured to present the DBPs formation. The results show alum and FeCl 3 removed biopolymer (Peak A), humic substances-like (Peak B, Peak C) at the same percentage, while low molecular weight acid and neutral (Peak D) showed a higher removal with alum than FeCl 3. HAAs removal led to a greater reduction than THMs removal, and FeCl 3 showed a higher removal than the alum coagulant. It indicated that alum and FeCl 3 coagulant have different ability in removing specific organic fractions, which are precursors of THMs and HAAs formation.

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A mini review of preoxidation to improve coagulation

Cited by 143 publications

References 130 publications

The effect of water treatment unit processes on cyanobacterial trichome integrity

The effect of water treatment unit processes on cyanobacterial trichome integrity

A Cyanotoxin Primer for Drinking Water Professionals

Assessment of Organic Fraction Based on Its Molecular Weight and Disinfection by-Product Formation Through Different Coagulant

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