The effects of matrices and ozone dose on changes in the characteristics of natural organic matter

A critical review on characterization strategies of organic matter for wastewater and water treatment processes

“…For instance, González et al (2013) have recently found that the concentration of the building blocks fraction increased after pre-treatment by both UV/H 2 O 2 and ozone. Interestingly, it has been revealed that there is no reduction of building blocks even after a long treatment period by advanced oxidation processes such as ozone or Fenton reactions (Selcuk et al, 2006;Molnar et al, 2013). This observation may help to optimize the pre-treatment of persistent OM by AOPs to avoid unnecessary expenditure on chemicals and energy, thereby lowering the operation cost in wastewater/water treatment processes.…”

“…However, AOPs are normally used to partially oxidize non-biodegradable OM with high molecular weight or recalcitrant OM to more biodegradable compounds due to the large consumption of energy and chemicals for complete oxidation and mineralization. The efficiency of AOPs in wastewater reclamation is influenced not only by the concentrations of OM but also by its physicochemical properties and molecular weight (Selcuk et al, 2006;González et al, 2013;Molnar et al, 2013). More recently, it has been demonstrated that the formation processes of disinfection by-products (DBPs) during chlorination and chloramination of secondary effluent for the production of high quality recycled water is affected by both the concentrations of DOM and DOM characteristics (Zhuo et al, 2001;Zhang et al, 2009;Doederer et al, 2014;Ma et al, 2014).…”

Uticaj Predozonizacije Na Uklanjanje Prekursora Trihalometana Koagulacijom

“…Utvrđeno je da se primenom koagulacije sa 15 mg Al/L PACl omogućava smanjenje PFTHM vrednosti za 34%, u odnosu na sirovu vodu. Međutim, uvođenjem oksidativnog predtretmana (0,25-0,5 mg O 3 /mg DOC), usled strukturnih promena POM, raste njihov potencijal ka formiranju bromovanih trihalometana (slika 3), što je u skladu sa literaturom (14). Jedino pri dozi ozona 0,8 mg O 3 /mg DOC ostvareno je povećanje efikasnosti uklanjanja prekursorskog materijala kombinovanim tretmanom sa PACl-om (PFTHM opada za 55%, u odnosu na sirovu vodu odnosno, za 30% u odnosu na koagulisanu vodu).…”

“…Dokazano je da ozon ima sposobnost da reaguje sa organskim supstancama i poveća njihovu biodegradabilnost, da omogućava smanjenje sadržaja prekursora hlorovanih nusproizvoda dezinfekcije, kao i mikroorganizama (10,(13)(14). Ukoliko se primenjuje u vidu predtretmana (15)(16), dokazano je da ozon pokazuje pozitivan efekat na uklanjanje POM tokom koagulacije i flokulacije, ali njegov pozitivan uticaj u velikoj meri zavisi od karakteristika vode (1,17) Cilj rada je bio da se u laboratorijskim uslovima ispita uticaj oksidacionog predtretmana ozonom na uklanjanje prirodnih organskih materija, kao prekursora trihalometana, koagulacijom sa polialuminijum-hloridom i gvožđe(III)-hloridom.…”

Overview of the Main Disinfection Processes for Wastewater and Drinking Water Treatment Plants

“…It is believed that the degradation of the residual chlorine dioxide and other final reaction products is faster than that observed in the case of chlorine and therefore these compounds should not represent a hazard to the aquatic environment [45]. During the disinfection with ozone, the formation of organic (e.g., aldehydes, carboxylic acids, and ketones) and inorganic (e.g., bromate) disinfection by-products has been well documented [46][47][48][49][50][51][52][53]. Ozone does not cause the formation of chlorinated by-products such as trihalomethane, but recent studies indicate that ozone induce the formation of NDMA [54][55][56].…”