RESUMO
2, 4, 6 trichlorophenol [TCP] is one of the most toxic chlorophenols which is very difficult to biodegradation. Advanced Oxidation Processes [AOPs] is one of the most effective processes for degradation of persistent compounds. Since the mineralization of recalcitrant compound by AOPs often requires long reaction time and strong doses of oxidant, the combination of this process with biological one, is considered as an efficient and economic method. In this work degradation of 2, 4, 6 trichlorophenol in aqueous solution with Fenton reagent [H2O2 +Ferrous ion] was studied. The experiment was done in batch mode, and the initial concentration of TCP was 0.60mM. In pH=3, H202=1.8mM, Fe=0.6mM, more than 99% of TCP was degraded in 10 minutes after the reaction was started. Chloride ion generation as TCP degradation by product was investigated, and it was found that the scavenging effect of chloride is negligible. PH and UV215 absorbance analysis, after reaction completion, indicated that generated intermediates had the less chlorinated nature, acidic properties and nonphenolic structure. Chloride ion increases from 0 mg/L to 40 mg/L, pH decreased from 3 to 2.7 and UV215 absorbance decreased from 3.2 to 0.6, therefore it can be resulted that their biodegradability modified and their recalcitrance reduced. COD analysis indicated that TCP did not mineralize and in H2O2/TCP = 3 and oxidation time of 1 h, COD reduction was only 37%.
Assuntos
OxirreduçãoRESUMO
Recycling process is developed in communities to decrease the volume of high solid wastes and prevent environmental pollution. Plastic is one of the most recyclable materials in municipal solid wastes [MSW] with a high rate of application during the last decades. PET [poly ethylene therphtalate] is one of the basic plastic compounds which are used in a variety of products such as textile fibers, bottles and other containers. Methods for PET recycling include mechanical and chemical processes and PET incineration. In this study which was conducted on MSW analysis in Qom [a city in the central region of Iran, known for increase of population and high migration, environmental pollutions such as high quantity of MSW, industries and vehicle contamination, noise pollution and municipal sewage], physical analysis of MSW was carried out to four geographical sites and in different seasons of the year 2002. Results showed the rate of PET production to be 0.44% of the total MSW production, depending on site characteristics and area, time and cultural specifications. It is concluded that approximately 700 tons of PET plastics are buried per year