Reach Us +44-1904-929220
Understanding the Role of Chlorine Dioxide as Pre-oxidant and Disinfectant | OMICS International
ISSN: 2165-784X
Journal of Civil & Environmental Engineering
Make the best use of Scientific Research and information from our 700+ peer reviewed, Open Access Journals that operates with the help of 50,000+ Editorial Board Members and esteemed reviewers and 1000+ Scientific associations in Medical, Clinical, Pharmaceutical, Engineering, Technology and Management Fields.
Meet Inspiring Speakers and Experts at our 3000+ Global Conferenceseries Events with over 600+ Conferences, 1200+ Symposiums and 1200+ Workshops on Medical, Pharma, Engineering, Science, Technology and Business
All submissions of the EM system will be redirected to Online Manuscript Submission System. Authors are requested to submit articles directly to Online Manuscript Submission System of respective journal.

Understanding the Role of Chlorine Dioxide as Pre-oxidant and Disinfectant

Yang X*
School of Environmental Science & Engineering, Sun Yat-sen University, Guangzhou, China
Corresponding Author : Xin Yang
School of Environmental Science & Engineering
Sun Yat-sen University, Guangzhou, China
Tel: 86-20-39332690
Email: [email protected]
Received April 29, 2015; Accepted April 29, 2015; Published May 08, 2015
Citation: Yang X (2015) Understanding the Role of Chlorine Dioxide as Pre-oxidant and Disinfectant. J Civil Environ Eng 5:172. doi:10.4172/2165-784X.1000172
Copyright: ©2015 Yang X. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Visit for more related articles at Journal of Civil & Environmental Engineering

Disinfection is always the first priority in water treatment works to remove or inactive pathogenic microorganisms and to protect people from waterborne infectious diseases. Chlorine is the prevalent disinfectant due to its broad-spectrum germicidal potency, low cost and well-established practices [1]. However, the inevitable formation of Disinfection By-Products (DBPs) is considered as one of the primary threats to human well-being. DBPs, such as Trihalomethanes (THMs) and Haloacetic Acids (HAAs), have been regulated by the United States Environment Protection Agency (U.S.EPA) and other national agencies. Alternative disinfectants, such as chlorine dioxide (ClO2), ozone, UV and chloramines are becoming popular [2,3]. Among these alternative disinfectants, ClO2 can be also applied for color removal, algal removal, and taste and odor control [4-6]. Its biocidal efficiency is equal or superior to chlorine over a wide pH range [7-10]. Application of ClO2 does not form appreciable levels of the chlorine-containing by-products such as Trihalomethanes (THMs) and Haloacetic Acids (HAAs) under typical water treatment conditions [11,12]. ClO2 is often used as preoxidant combined with post-chlorination or -chloramination or used as disinfectant to inactivate microorganism and provide residual in the distribution system.
The major DBPs from application of ClO2 are chlorite (ClO2 -) and chlorate (ClO3-). Approximately 70% of applied ClO2 forms chlorite, while about 10% forms chlorate [13]. Due to the health concerns over chlorite and chlorate, the maximum contaminant level (MCL) for chlorite in drinking water is regulated at 1.0 mg/L in the United States [14]. In the new Chinese Sanitary Standards for Drinking Water, it has been regulated at the threshold value of 0.7 mg/L for both chlorite and chlorate (Chinese Sanitary Standards for Drinking Water, 2006). Thus, the doses of ClO2 should be controlled to prevent the excessive formation of chlorite and chlorate.
¨Natural organic matter (NOM) is precursor of DBPs. Understanding the reactions between Natural Organic Matter (NOM) and ClO2 can help clarify the role of ClO2 during pretreatment. Previous study showed that chlorine dioxide destroys the aromatic and conjugated structures of Natural Organic Matter (NOM) and transforms large aromatic and long aliphatic chain organics to small and hydrophilic organics [15]. Oxidation of NOM with ClO2 also generates organic by-products such as aldehydes and long chain carboxylic acids, which affected DBP formation during subsequent chlorination/chloramination [16]. It has been shown that ClO2 oxidation prior to chlorination can reduce the formation of THM and Total Organic Halogen (TOX) [17]. A recent study has reported that ClO2 preoxidation reduced THM, HAA, HAN and CH formation during subsequent chlorination [15]. ClO2 pre-oxidation reduces the NDMA Formation Potential (FP) of natural water sources by 32-94% [18]. But enhanced NDMA formation after ClO2 pre-oxidation has also been reported in wastewater-impacted waters [19]. Thus, the current understanding of the reactions between NOM and ClO2 is still quite limited and the role of ClO2 for subsequent DBP formation still needs further exploration.
Emerging DBPs, such as Iodo-Trihalomethanes (I-THMs), have been reported to form when ClO2 disinfects waters containing iodide and NOM. In iodide-containing waters, ClO2 can react with iodide to form Hypoiodous Acid (HOI), which reacts with NOM to form iodinated DBPs, including I-THMs [20,21]. The formation is affected by many factors, including reaction time, pH, temperature, disinfectant doses, concentration, bromide ion concentrations and precursor properties. The generation of byproducts from the application of ClO2 is still not clear. The reaction mechanisms behind is worth further exploration.
Select your language of interest to view the total content in your interested language
Post your comment

Share This Article

Relevant Topics

Article Usage

  • Total views: 12805
  • [From(publication date):
    June-2015 - Oct 24, 2019]
  • Breakdown by view type
  • HTML page views : 8961
  • PDF downloads : 3844