| Title | TEMPERATURE ACTIVATED DEGRADATION (MINERALIZATION) OF 4-CHLORO-3-METHYL PHENOL BY FENTON'S REAGENT |
| Abstract | With the aim to evaluate the effect of temperature,4-chloro-3-methyl phenol (CMP) degradation by Fentons
reagent was investigated at 25 and 70 C under the following initial conditions: [CMP]0 = 10 mM,[Fe 2+]0 = 0.5 mM;
([H2O2]0/[CMP]0)=80,pH 0 = 3. The results indicated that CMP degradation was strongly influenced by temperature.
In fact,the maximum TOC removal,achieved after ca. 24 h,was by far greater at 70 C (85%) than at 25 C (36%).
The same happened for organic chlorine (TOX) conversion into inorganic chloride,i.e. 100%,after 3 h at 70 C,
and 87%,after 27 h at 25 C. As the recorded trends of CMP removal and chloride formation were basically the same,
hydroxy substitution (ipso-substitution) was hypothesised as one likely mechanism of CMP degradation. The higher
level of mineralization recorded at 70 C was ascribed to: (i) a greater OH concentration; (ii) a consequently greater
extent of CMP oxidation to organic acids; (iii) a higher decarboxylation rate of such acids. An interesting consequence
of such extended organic acids decarboxylation was a pH increase up to 8 that,in turn,caused,in the treated mixture,
the decomposition of excess H2O2 as well as the precipitation of iron ions. These two latter outcomes are technologically
important considering that usually,before discharging Fenton treated wastewater,specific polishing steps are
required just to remove iron ions,decompose excess hydrogen peroxide and neutralise the pH.
2004 Elsevier Ltd. All rights reserved. |
| Source | Chemosphere 59, pp. 397–403 |
| Keywords | 4-Chloro-3-methyl phenolFentons reagentOxidation processesOxidation by-products |
| Journal | Chemosphere |
| Editor | Elsevier, Oxford, Regno Unito |
| Year | 2005 |
| Type | Articolo in rivista |
| Authors | Antonio Lopez; Giuseppe Mascolo; Antonia Detomaso; Giangiuseppe Lovecchio; Giuseppe Villani |
| Text | 42179 2005 4 Chloro 3 methyl phenol Fentons reagent Oxidation processes Oxidation by products TEMPERATURE ACTIVATED DEGRADATION MINERALIZATION OF 4 CHLORO 3 METHYL PHENOL BY FENTON S REAGENT Antonio Lopez; Giuseppe Mascolo; Antonia Detomaso; Giangiuseppe Lovecchio; Giuseppe Villani Istituto di Ricerca Sulle Acque, Consiglio Nazionale delle Ricerche, Via F. De Blasio 5, 70123 Bari, Italy With the aim to evaluate the effect of temperature,4 chloro 3 methyl phenol CMP degradation by Fentons reagent was investigated at 25 and 70 C under the following initial conditions CMP 0 = 10 mM, Fe 2 0 = 0.5 mM; H2O2 0/ CMP 0 =80,pH 0 = 3. The results indicated that CMP degradation was strongly influenced by temperature. In fact,the maximum TOC removal,achieved after ca. 24 h,was by far greater at 70 C 85% than at 25 C 36% . The same happened for organic chlorine TOX conversion into inorganic chloride,i.e. 100%,after 3 h at 70 C, and 87%,after 27 h at 25 C. As the recorded trends of CMP removal and chloride formation were basically the same, hydroxy substitution ipso substitution was hypothesised as one likely mechanism of CMP degradation. The higher level of mineralization recorded at 70 C was ascribed to i a greater OH concentration; ii a consequently greater extent of CMP oxidation to organic acids; iii a higher decarboxylation rate of such acids. An interesting consequence of such extended organic acids decarboxylation was a pH increase up to 8 that,in turn,caused,in the treated mixture, the decomposition of excess H2O2 as well as the precipitation of iron ions. These two latter outcomes are technologically important considering that usually,before discharging Fenton treated wastewater,specific polishing steps are required just to remove iron ions,decompose excess hydrogen peroxide and neutralise the pH. 2004 Elsevier Ltd. All rights reserved. 59 Articolo Pubblicato 69.pdf Articolo in rivista Elsevier 0045 6535 Chemosphere Chemosphere Chemosphere Chemosphere. Chemosphere. Environmental chemistry, Chemosphere. Persistent organic pollutants and dioxins, Chemosphere. Environmental toxicology and risk assessment, Chemosphere. Science for Environmental toxicology, DETOMASO ANTONIA antonio.lopez LOPEZ ANTONIO giuseppe.mascolo MASCOLO GIUSEPPE TA.P07.002.002 Sviluppo di nuovi processi di controllo dell inquinamento idrico. |
