The presence of pharmaceuticals and personal care products(PPCPs)in the aquatic environment may pose potential threat to the ecosystem and human health,hence PPCPs have aroused much concern over the world.The contamination of PPCPs in the groundwater,the main source of drinking water supply in many countries and regions,has been extensively studied in the last decade.This paper reviews the occurrence of frequently detected PPCPs,including antibiotics,anti-inflammatories,lipid-regulators,carbamazepine,caffeine,and N,N-diethyl-m-toluamide in groundwater,with special concern to the progress made over the past three years.Possible emission sources for PPCPs in groundwater,such as wastewater and contaminated surface water,landfills,septic systems,livestock breeding and sewer leakage,are summarized.Besides,adsorption,migration and degradation,the dominant mechanisms in the subsurface transport and fate of PPCPs,are discussed,and the insights into the future study of PPCPs in the groundwater are provided.
The thermally activated persulfate （PS） degradation of carbon tetrachloride （CT） in the presence of formic acid （FA） was investigated. The results indicated that CT degradation followed a zero order kinetic model, and CO2^- was responsible for the degradation of CT confirmed by radical scavenger tests. CT degradation rate increased with increasing PS or FA dosage, and the initial CT had no effect on CT degradation rate. However, the initial solution pH had effect on the degradation of CT, and the best CT degradation occurred at initial pH 6. Cl^- had a negative effect on CT degradation, and high concentration of Cl^- displayed much strong inhibition. Ten mmol·L^-1HCO3^- promoted CT degradation, while 100mmol·L^-1NO3^- inhibited the degradation of CT, but SO4^2- promoted CT degradation in the presence of FA. The measured Cl^- concentration released into solution along with CT degradation was 75.8% of the total theoretical dechlorination yield, but no chlorinated intermediates were detected. The split of C-Cl was proposed as the possible reaction pathways in CT degradation. In conclusion, this study strongly demonstrated that the thermally activated PS system in the presence of FA is a promising technique in in situ chemical oxidation （ISCO） remediation for CT contaminated site.
Minhui XUXiaogang GUShuguang LUZhouwei MIAOXueke ZANGXiaoliang WUZhaofu QIUQian SUI
