THE APPLICATION OF CHEMISTRY IN ENVIRONMENT
Year:2010 | Volume:1 | Issue:1|Papers Count:8

The thermal degradation of isotactic polypropylene (I-pp) was carried out in the absence and presence of various concentrations of B215. A method of viscometry was used to study the degradation behavior and Kinetics model was developed to estimate the degradation rate constant. The thermal degradation properties of polymer have been studied by differential scanning Calorimetry (DSC) and melt flow index (MFI). Experimental data indicated that the presence of B215 greatly decreased the rate of degradation of PP. We were indicated that the degradation of polymer in air has greater value than that of in N2 atmosphere.

One of the most effective methods for degradation of aromatics is advanced oxidation processes, such as ozonation. The model compound was 4-nitro phenol that carried carried at pH (3), (7) and (9) under ozonation during 30 min. Ozonation of 4-nitro phenol was occurred where the Ozone concentration can be considered constant and analysis of concentration, UV Absorbance, COD and TOC and NO3- ions was mentioned during ozonation. Result show that the highest removing rate of 4-nitrophenol achieved at alkaline conditions, i.e., the indirect mechanism of hydroxyl radical attack on 4-nitro phenol.Among the by-products formed during the ozonation of 4-nitrophenol formed during ozonation was quinine.

In this work advanced oxidation process was investigated for removal of phenol from water polluted by BHT oils using O3 alone and ozonation catalyzed with Titanium oxide (TiO2). Effect of catalyst and dose of it on degradation of phenol have been studied at pH 7. Some studied parameters like catalyst, ozonation time and ozone flow rate had positive effect on increasing the rate of ozonation. The results of HPLC and UV analyses were used for detecting of phenol during ozonation reaction and study the effect of TiO2 catalyst on the degradation rate of phenol. TOC and COD removal percentage have been detected in different ozonation times in presence and absence of catalyst. The effect of ozone flow rate on degradation of phenol and also, removal of COD and TOC has been studied. The present study validate that ozonation is a safe, economic and promising process for the removal of phenol from different industries waste water.

From 10 million registered compounds, nearly 6, 2% of compound in chemical abstract have C-F bond. In organic compound, existing Flour increases constancy of vehemence and oxidation and change electrical effectence.Moreover it increases effectence of lipophilic. Different methods of Fluorination of compound with preservation of conformation and also high yield are aim of Fluorination reactions.

This project was performed out in study of degradation of 2-CEPS with nanosized ZnO under different conditions. Degradation of 2-chloroethylphenylsulfide with nanosized and non-nanosized ZnO under different conditions has been studied using GC and GC-MS. Experiments were carried out upon different samples of ZnO (dry and wet nano and non-nanosized) under ultraviolet radiation and absent of it.On the surface of the very reactive ZnO particles, 2-chloroethylphenylsulfide undergoes degradation reaction to yield 2-hydroxyethylphenylsulfiede, 2-ethoxyethylphenylsulfde, and vinylphenylsulfide as products.The results show that the maximum degradation of 2-chloro ethylphenylsulfide is obtained on the surface of wet nanosized ZnO in present of UV.

Polyacrylamide hydrogels were prepared with an exothermic free radical polymerization method With n,n’- methelene bisacrilamide as cross linker & AIBN as initiator.The rate of Hydrogel swelling in metal cationic solutions with different cations and pH was investigated. Then three kinds of hydrogel with different amount of cross linker were prepared and their swelling behavior were investigatedThe results showed that; variation of pH had no effect on hydrogel swelling, but the complex hydrogels had maximum swelling in alkaline pH. With increasing of cations concentration in solution and cross linker amount in hydrogel the rate of swelling was decreased.

Polyacrylamide hydrogels were prepared with an exothermic free radical polymerization method With n,n’- methelene bisacrilamide as cross linker & AIBN as initiator.The hydrogels were participated in complex formation reaction with metal cations and Phosphate solutions with different concentrations were prepared. IR spectrum was used for investigation of complex formation and phosphate adsorption kinetics also was investigated with UV spectrophotometer.Comprising of hydrogel complexes with “copper and nickel, to ferrous” showed that:Complexes with copper and nickel had relatively higher adsorption than ferrous complex and maximum adsorption was observed after 6 hours from beginning. The adsorption was increased with increasing of phosphate concentration.

An advanced oxidation process of salicylic acid by using ozone has been studied. A nominal concentration of 80- 100 mgL-1 of the salicylic acid was chosen, which normally occurs in food industry wastewaters. The effect of oxidation concentration and pH on COD and TOC has been studied. It was observed that the highest removing rate of these factors achieved at alkaline and some neutral conditions, i.e., the indirect mechanism of hydroxyl radical attack on the molecule under study. During ozonation of salicylic acid reduction of COD and TOC reached up to 68/89% and 38/65%, respectively. From HPLC peaks, it can be deduced that nearly the whole ozonation intermediates produced during ozonation disappear by 19.1 mg O3L-1 A real sample of wastewater was chosen that contains salicylic acid. Biodegradability of wastewaters, measured as BOD5/COD, increases from 0.43 (untreated wastewater) to nearly 0.97 during ozonation