V. Sridevi

Implementation of response surface methodology for phenol degradation using Pseudomonas putida (NCIM 2102)

Phenol, a major pollutant in several industrial wastewaters is often used as a model compound for studies on biodegradation. Experiments were performed as a function of glucose (0.4-1.6 g/l), ammonium sulfate (0.5- 2.0 g/l) and concentration of metal ion, Mn2+ (0.01-0.04 g/l) by Pseudomonas putida (NCIM 2102), at constant phenol concentration 0.100 gL-1. Optimization of these three process parameters for phenol degradation was studied. Statistically designed experiments using response surface methodology (RSM) was used to get more information about the significant effects and the interactions between the three parameters. A 23 full - factorial central composite designed technique was employed for experimental design and analysis of the results. The optimum process conditions for maximizing phenol degradation (removal) were recognized as follows; glucose (0.8229 g/l), ammonium sulphate(1.5183 g/l) and metal ion concentration, [Mn2+.]( 0.0195 g/l) A maximum % phenol degradation of 98.24 was obtained at these optimum parameters.

Reproductive Epidemiology in Radiographers Exposed to Diagnostic X-rays

Abstract In the present study reproductive performance of 195 workers employed in various hospitals in Hyderabad was evaluated using standard questionnaire. The workers were exposed to X-rays while handling the patients for diagnostic purposes. 210 individuals belonging to same age and socioeconomic group but not exposed to radiation and toxic chemicals were studied for control data. Statistical analysis revealed a significant increase in the frequency of stillbirths and neonatal deaths in the offspring of the exposed group when compared to the controls. There was an increase in the incidence of congenital defects but the increase was not statistically significant. A decrease in the frequency of live births was observed in the offspring of the exposed group when compared to the data from controls. The increase in abortions among the wives of exposed workers was significant.