Degradation and removal of naphthalenesulphonic acids by means of adsorption and ozonation catalyzed by activated carbon in water

Abstract

[1] Studies were conducted on the efficiency of systems based on the use of ozone, activated carbon, and ozone/activated carbon in the treatment of waters containing 1-naphthalenesulphonic acid, 1,5-naphthalenedisulphonic acid, and 1,3,6-naphthalenetrisulphonic acid. In the removal of these acids by adsorption on activated carbon the elevated heights of the mass transfer zone columns and the low values of the breakthrough volumes indicated that a system exclusively based on the use of activated carbon is not appropriate for the removal of these pollutants. In the ozonation of these acids the reactivity of naphthalenesulphonic acid with ozone is low. In addition, the initial concentration of total organic carbon (TOC) was not reduced during naphthalenesulphonic acids ozonation. These results indicate that a system exclusively based on the use of ozone is not adequate to decontaminate water where these acids are present. These ozonation processes were also studied in the presence of activated carbon. The presence of activated carbon enhanced the elimination rate, probably by enhancing ozone decomposition in aqueous phase in highly oxidative species. These catalytic properties seem to be favored by both the basicity of the carbon surface and the higher macropore volume. The catalytic properties of activated carbon were reduced by ozonation. New acid groups such as anhydride, lactones, and carboxylic acid were generated on the activated carbon surface during ozone treatment. This effect reduced the reactivity of the activated carbon to ozone and therefore the capacity to enhance ozone decomposition in aqueous phase. The presence of activated carbon during naphthalenesulphonic acid ozonation produced a reduction in the TOC concentration and in the genotoxicity of the degradation products. All these results indicate that this novel combined system is very promising for the treatment of water polluted with organic matter.INDEX TERMS: 1806 Hydrology: Chemistry of fresh water; 1871 Hydrology: Surface water quality; 1899 Hydrology: General or miscellaneous; KEYWORDS: naphthalenesulphonic acids, ozonation, activated carbon, catalyst Citation: Rivera-Utrilla, J., and M. Sánchez-Polo, Degradation and removal of naphthalenesulphonic acids by means of adsorption and ozonation catalyzed by activated carbon in water, Water Resour.

Degradation of recalcitrant compounds from stabilized landfill leachate using a combination of ozone-GAC adsorption treatment

“…After ozone treatment, the basic sites were transformed into acid ones. Carbonyl-and carboxyl-type oxygenated functional groups that predominated on the surface of GAC were the main causes of the development of the negative surface charge on GAC [52]. In this case, ozone treatment on the surface of GAC might increase its polarity, thereby enhancing its electrostatic interactions with the positive charge of organic contaminants in the solution for a higher removal [58,59].…”

“…The reduction of color intensity clearly indicated that there was a direct attack of ozone on the double bonds of GAC (in the chromophoric parts) during the ozone treatment [51]. After ozonation had decomposed the recalcitrant compounds into smaller molecules, the organic materials in the leachate became more easily biodegradable, enabling GAC to easily adsorb the remaining organic materials unchanged during the ozonation [52]. This is one of the advantages of using this combined treatment for the removal of refractory compounds from stabilized leachate.…”

Decolourisation of dyes and dyehouse effluent in a bubble‐column reactor by heterogeneous catalytic ozonation

“…It then proceeded in the aqueous phase and accelerated the transformation of ozone into secondary radicals such as hydroxyl radicals ( • OH) 20. On the other hand, several researchers have opined that improved pollutant decomposition occurred not because of the formation of radicals, but because of the surface basicity of activated carbon, which enhances ozone decomposition forming highly oxidative species; even mineral matter present in the carbon as an impurity also plays a major role 28–31. In our study, after filtration, the suspended activated carbon was filtered and desorption of dye molecules was carried out, but no colourant molecule was released.…”

Characteristics and Behavior of Different Catalysts Used for Water Decontamination in Photooxidation and Ozonation Processes

“…The Fe 2p 3/2 spectrum for samples C-1 and C-1-ozonated shows a 14% increase in the surface concentration of Fe 2 O 3 on C-1-ozonated. According to these findings, the ozone can attack Fe(II) metal sites on the carbon surface during NTA ozonation, generating Fe(III) by Equations ( 49) and (50). These reactions can also enhance ozone transformation rate into HO • radicals, contributing to the ozonation of NTS.…”

“…), Norit; (+), Sorbo; (-) Witco (reproduced from [50] with permission of John Wiley and Sons, 2003).…”