Inhibitory effect of veterinary antibiotics on denitrification in groundwater: a microcosm approach.

Veterinary antibiotics in groundwater may affect natural microbial denitrification process. A microcosm study was conducted to evaluate the influence of sulfamethazine and chlortetracycline at different concentrations (0, 0.01, 0.1, and 1.0 mg/L) on nitrate reduction in groundwater under denitrifying condition. Decrease in nitrate removal and nitrite production was observed with the antibiotics. Maximum inhibition of nitrate removal was observed after seven days of incubation with 0.01 mg/L sulfamethazine (17.0%) and 1.0 mg/L chlortetracycline (15.4%). The nitrite production was inhibited with 1.0 mg/L sulfamethazine to 82.0% and chlortetracycline to 31.1%. The initial/final nitrate concentrations indicated that 0.01 mg/L sulfamethazine and 1.0 mg/L chlortetracycline were most effective in inhibiting activity of denitrifying bacteria in groundwater. After 12 days of incubation, the sulfamethazine biodegradation was observed whereas chlortetracycline was persistent. Sulfamethazine and chlortetracycline in groundwater could inhibit the growth and capability of naturally occurring denitrifying bacteria, thereby threatening nitrate pollution in groundwater.

Influence of community satisfaction with individual happiness: comparative study in semi-urban and rural areas of Tikapur, Nepal.

Happiness is a subjective indicator of overall living conditions and quality of life. Recently, community- and national-level investigations connecting happiness and community satisfaction were conducted. This study investigated the effects of community satisfaction on happiness in Nepal. A factor analysis was employed to examine 24 items that are used to measure community satisfaction, and a multiple regression analysis was conducted to investigate the effects of these factors on happiness. In semi-urban areas, sanitation showed a positive relationship with happiness. In rural areas, edu-medical services were negatively related to happiness, while agriculture was positively related. Gender and perceived health were closely associated with happiness in rural areas. Both happiness and satisfaction are subjective concepts, and are perceived differently depending on the socio-physical environment and personal needs. Sanitation, agriculture (food) and edu-medical services were critical factors that affected happiness; however, the results of this study cannot be generalized to high-income countries.