Photoexcitation-induced efficient detoxification and removal of arsenite in contaminated water by a layered double hydroxide-supported polyacrylate stabilized ferrous sulfide composite.

The effective detoxification and removal of arsenite (As(III)) has been widely concerned because of its strong toxicity and migration ability. In this study, we designed a layered double hydroxide-supported polyacrylate stabilized ferrous sulfide composite (PAA/FeS@LDH) and coupled it with UV excitation to purify As(III)-polluted water. The removal efficiency of As(III) under UV irradiation reached almost 100% in 120 min, and the first-order kinetic constant was 3.12 orders of magnitude higher than under dark. UV irradiation significantly accelerated the oxidation and detoxification of As(III) at the interface of PAA/FeS@LDH and treatment solution. It is attributable to the generation of reactive oxygen species (ROS) intermediates, including .O2-, .OH, and SO4.- under UV irradiation, because of the presence of the photogenerated electron-hole pairs and iron valence states cycles. Importantly, .O2- may be rapidly captured and oxidized to 1O2 on the surface of PAA/FeS@LDH that is also an important contributor to the oxidation removal of As(III). Noticeably, As(III) concentrations in the real water were rapidly reduced to below the guideline limitation of drinking water (10 µg/L) within 20 min under UV irradiation. Our outcomes provide a novel photoexcitation treatment system for the efficient detoxification and removal of As from actual wastewater.

[Correlates of and willingness to participate in HIV voluntary counseling and testing among migrants in a city of Shanxi province].

OBJECTIVE: To determine the correlates of and willingness to participate(WTP) in HIV voluntary counseling and testing (VCT) among migrants in Shanxi province. METHODS: Through quota sampling, a total of 1280 migrants were recruited from 6 different venues where migrants were most likely employed to administer a face-to-face anonymous interview. RESULTS: Knowledge of VCT among migrants was low. Only 56.6% of migrants had heard of HIV voluntary counseling and testing. 64.5% reported willingness to accept VCT after participants were informed that HIV counseling and testing was offered free of charge Centers for Disease Prevention and Control (48.7%), hospital (27.0%) and home (18.5%) were most preferred places for VCT service. Logistic regression analysis indicated that the willingness was associated with having a history of HIV test, having better knowledge of HIV, no discrimination against people with HIV, and high HIV/AIDS perception. CONCLUSION: Community-based health education programs for improving HIV/AIDS knowledge, promoting acceptance of VCT and eliminating discrimination to HIV-infected persons were called for.