Feasibility analysis of SO_2 absorption using a hydrophilic ceramic membrane contactor

Hydrophilic ceramic membranes would be potential candidates for membrane gas absorption if they could be applied to appropriate separation processes.This study highlights a novel concept for the practical implementation of SO_2 absorption in hydrophilic ceramic membrane that exhibits outstanding thermal and mechanical stabilities.With this aim,we investigated experimentally the performance of SO_2 absorption into aqueous sodium hydroxide (NaOH) solution in a hydrophilic alumina (Al_2O_3) membrane contactor in terms of SO_2 removal efficiency and SO_2 mass transfer flux,and compared the performance with that in a hydrophobic one.A series of experiments were performed at various conditions over a NaOH concentration range of 0–1.0 mol·L^(-1),a liquid flow rate range of 30–180 ml·min^(-1),a gas flow rate range of 120–1000 ml·min^(-1),an inlet SO_2 concentration range of 400–2000μl·L^(-1),and a temperature range of 10–35°C.It was found that the hydrophilic membrane was more competitive when using a NaOH concentration higher than 0.2 mol·L^(-1).Furthermore,it can be inferred that the hydrophilicα-Al_2O_3 membrane exhibited exceptional long-term stability under 480 h continuous operation.

The prevalence of soil transmitted helminths and its infuential factors in Shandong Province, China: an analysis of surveillance data from 2016 to 2020

Background Soil-transmitted helminths(STHs)were previously endemic in Shandong Province,China.This study aimed to analyze the STHs prevalence trend and the natural,social,and human cognitive and behavioural factors infuencing the discrepancies between high and low infection levels from 2016 to 2020 in Shandong Province in eastern China.Methods STHs surveillance data of Shandong Province from 2016 to 2020 were obtained from China Information Management System for Prevention and Control of Parasitic Diseases.STHs infections were detected by modifed Kato–Katz method.Comprehensive information on the natural and social factors,STHs-related knowledge and behaviours were collected through questionnaire surveys.Retrospective spatial scan analysis was performed using SaTScan v10.1 to evaluate any identifed spatial clusters of STHs infection for statistical signifcance and Bayes discriminant analysis was used to discriminate the high or low infection groups of the villages.Results In total,72,160 participants were involved in our survey from 2016 to 2020.The overall STHs prevalence rate was 1.13%,with the eastern region of Shandong Province having the highest rate(2.02%).The predominant species was T.trichiura,with the prevalence rate of 0.99%and the≥70-year age group possessed the highest rate of 2.21%.The STHs prevalence rate showed an annual linear downward trend from 2016 to 2020(χ_(trend)^(2) =127.600,P<0.001).Respondents aged≥60 years had the lowest awareness level of STHs-related prevention knowledge(all P<0.05),and were the most likely to adopt the practice of fertilizing with fresh stool(χ^(2)=28.354,P<0.001).Furthermore,the southern region demonstrated the highest temperature and rainfall level and the lowest GNP and annual net income per capita(all P<0.05).Conclusions There is a remarkable declining in STHs prevalence in Shandong Province from 2016 to 2020.However,the prevalence rates of STHs especially T.trichiura in the southern and eastern regions were still high,and the elderly were more susceptible to be infected with STHs owning to their low awareness level of STHS-related prevention knowledge and high adoption rate of dangerous production and living behaviours.Integrated approaches of health education,environment improvement and behaviour change should be strengthened to obtain a further reduction of STHs prevalence in China.