Methylparaben chlorination in the presence of bromide ions and ammonia: kinetic study and modeling

The impacts of chlorination on methylparaben (MP) removal, as well bromide and ammonia the MP elimination kinetics, were studied. Bromide react with chlorine are promptly transformed into bromine chloramines, respectively. Rate constants chlorine, bromine, monochloramine determined under different pH conditions. At 8.5, apparent second-order rate reactions found to be 3.37(±0.50) × 101 2.37 (±0.11) 106 M-1.s-1 for kChlorine/MP kBromine/MP, respectively, yet there was low reactivity ( $$ {\mathrm{k}}_{{\mathrm{NH}}_2\mathrm{Cl}/\mathrm{MP}} = 0.045 M-1.s-1). Regarding bromination, in order gain further insight observed pH-dependence reaction, elementary considered corresponding calculated. experimental modeled values quite consistent these Then, experiments and/or concentrations performed assess impact inorganic water content a kinetic model designed degradation. Under conditions, degradation enhanced presence whereas it inhibited ammonia, overall dependent.