A Novel Anaerobic Gravity-Driven Dynamic Membrane Bioreactor (AnGDMBR): Performance and Fouling Characterization.

Despite numerous studies undertaken to define the development and significance of the dynamic membrane (DM) formed on some coarse materials, the optimization of reactor configuration and the control of the membrane fouling of anaerobic dynamic membrane bioreactor (AnDMBR) need to be further investigated. The aim of this study was to design a novel anaerobic gravity-driven dynamic membrane bioreactor (AnGDMBR) for the effective and low-cost treatment of municipal wastewater. An 800 mesh nylon net was determined as the optimal support material based on its less irreversible fouling and higher effluent quality by the dead-end filtration experiments. During the continuous operation period of 44 days, the reactor performance, DM filtration behavior and microbial characteristics were studied and compared with the results of recent studies. AnGDMBR had a higher removal rate of chemical oxygen demand (COD) of 85.45 ± 7.06%. Photometric analysis integrating with three-dimensional excitation-emission matrix fluorescence spectra showed that the DM effectively intercepted organics (46.34 ± 16.50%, 75.24 ± 17.35%, and 66.39 ± 17.66% for COD, polysaccharides, and proteins). The addition of suspended carriers effectively removed the DM layer by mechanical scouring, and the growth rate of transmembrane pressure (TMP) and the decreasing rate of flux were reduced from 18.7 to 4.7 Pa/h and 0.07 to 0.01 L/(m2·h2), respectively. However, a dense and thin morphological structure of the DM layer was still observed in the end of reactor operation and plenty of filamentous microorganisms (i.e., SJA-15 and Anaerolineaceae) and the acidogens (i.e., Aeromonadaceae) predominated in the DM layer, which was also embedded in the membrane pore and led to severe irreversible fouling. In summary, the novel AnGDMBR has a superior performance (higher organic removal and lower fouling rates), which provides useful information on the configuration and operation of AnDMBRs for municipal wastewater treatment.

Inequities in consistent condom use among sexually experienced undergraduates in mainland China: implications for planning interventions.

BACKGROUND: Since pre-exposure prophylaxis (PrEP) is mainly prescribed to high-risk uninfected individuals, consistent condom use (CCU) continues to be recommended as an inexpensive, feasible, practical and acceptable way to prevent the general population from acquiring and transmitting HIV through sexual intercourse. The objective of this cross-sectional study was to compare the relative importance of various determinants of CCU among sexually experienced undergraduates in mainland China so as to assess and subsequently to suggest ways to eliminate inequities in its use. METHOD: From September 10, 2018, to January 9, 2019, an anonymous self-administered online questionnaire was voluntarily completed by 12,750 participants distributed across 30 provinces in mainland China (except for Tibet). The present analysis was restricted to 2054 sexually experienced undergraduates. Pearson's chi-square test and Logistic regression models were chosen to analyze the factors associated with CCU. RESULTS: The overall rate of CCU was 61.3% [95% confidence interval (CI) = 59.2-63.4%]. CCU was inequitably distributed since enabling factors exerted greater effects than predisposing and need variables. Compared with heterosexual men, heterosexual women [adjusted odds ratio (AOR) = 0.78, 95% confidence interval (CI):0.64-0.96)], non-heterosexuals men (AOR = 0.64, 95% CI:0.45-0.92) and women (AOR = 0.68, 95% CI:0.47-0.99) were less prone to using condoms consistently. Those with more resources [i.e., higher levels of self- efficacy for condom use (AOR = 2.86, 95% CI:2.35-3.49) and being knowledgeable of the national AIDS policy (AOR = 1.50, 95% CI:1.23-1.82)], and those with lower need for condoms [i.e., late initiation of sexual activity (AOR = 1.34, 95% CI:1.09-1.64) and single sexual partner (AOR = 1.68,95% CI:1.21-2.33)] were more likely to be consistent condom users. CONCLUSIONS: In order to increase consistency of condom use and simultaneously reduce the remaining inequities, a comprehensive intervention measure should be taken to target heterosexual women, non-heterosexual men and women, and those with higher need for condoms, improve their condom use self- efficacy and raise their awareness of the national AIDS policy.

The prevalence of and factors associated with willingness to utilize HTC service among college students in China.

BACKGROUND: College students in China are emerging as one of the most vulnerable groups to contract HIV, because they are in a sexually active age group and also because of their open attitude toward sex and high risk sexual behaviors. This study aimed to explore the prevalence of willingness among college students to utilize HIV testing and counseling (HTC) service and the factors that may affect willingness, including predisposing, enabling and need factors, based on the Andersen's behavioral model. METHODS: A cross-sectional study was conducted from October 6, 2016 to December 31, 2016 in Hubei University of Science and Technology in China. After signing informed consent, college students completed a self-designed online questionnaire distributed via  https://www.wjx.cn/ voluntarily, anonymously and confidentially. Pearson's chi-square test and Logistic regression models were chosen to analyze the factors associated with willingness to utilize HTC service. RESULTS: Out of 3314 college students in the sample, 2583 (77.9%) expressed their willingness to utilize HTC service. After adjustment, those with low levels of discrimination towards people living with HIV (PLHIV) (OR = 1.41, 95%CI:1.17-1.68), being more knowledgeable about free HTC service centers (OR = 1.44, 95%CI:1.17-1.77), having recognized the necessity to provide HTC service in the local university (OR = 2.20, 95%CI:1.73-2.80), and having a higher HIV risk perception (OR = 1.64, 95%CI:1.37-1.95) were more willing to utilize HTC service, compared with their respective counterparts. CONCLUSIONS: In order to improve their willingness to utilize HTC service and finally to achieve the goal of zero-AIDS, a comprehensive intervention measure should be taken to publicize HTC service, eliminate stigma and discrimination against PLHIV, recruit and train peer volunteers to serve in the local university, and increase self-perceived risk of HIV infection.