Microbial electrochemical recovery of zinc

Electrolytic recovery of zinc (Zn) from aqueous solutions is an energy intensive process carried out using highly concentrated Zn2+ solutions. To reduce the energy consumption and make Zn recovery possible from dilute waste streams, a more energy-efficient process is needed. In this study, we tested a microbial electrolysis cells for Zn recovery from acidic solutions. The reactors contained biological anodes that generated current by oxidizing acetate. The reactors were operated with either controlled anode potential or controlled cathode potential. During operation with controlled anode operation, the energy efficiency for Zn recovery was highly variable and depended on the biologically generated current and the Zn2+ concentration in the catholyte. During operation with controlled cathode potential, a relatively stable energy consumption of 0.59–0.72 kWh kg−1 Zn was obtained. This was about three times lower than the energy consumption for Zn recovery under abiotic conditions

Disinfection byproduct formation from chlorination of agricultural reuse water sources

Treatment of reuse water sources is critical for achieving proper water quality for the desired end-use. Disinfection is often achieved through chlorination, but this leads to the formation of toxic disinfection byproducts (DBPs). During reuse for agricultural purposes, it is important to reduce the potential for contamination of food crops and thereby minimize DBP production from treatment processes. This study evaluates the DBP formation potential from various reuse water sources under different reaction conditions to determine the implications of chlorination-derived DBPs for agricultural water reuse. Chlorination experiments were conducted on wastewater, stormwater, and farm lagoon water at pH 5, 6, 7, and with Br− addition. DBP concentrations were then evaluated in conjunction with initial concentrations of dissolved organic carbon (DOC), total nitrogen (TN), initial bromide, and specific UV-absorbance (SUVA). The most abundantly formed DBP class for nearly all sources was trihalomethanes (THMs), followed by nitrogenous DBPs (N-DBPs). Despite a high DOC concentration of 37.8 mg/L, lagoon source 2 only formed a total of 4.15 µg/L DBPs, likely due to oxidation of the inorganic nitrogen (54.8 mg/L TN) inhibiting DBP formation. Stormwater sources (DOC range 3.0-15.3 mg/L) had the highest DBP formation potential, with chloroform concentrations reaching up to 92 µg/L. Waters with lower DOC, TN and bromide and at lower pH ranges had less DBP formation potential for the compounds evaluated in this study. While SUVA did not prove to be a strong indicator of DBP formation, with increasing Br/UVA, there was an exponential increase in bromine substitution factor for THMs (R2=0.927, p < 0.0001) across all reuse sources. Toxicity-weighted DBP concentrations were also evaluated for all sources. Waters with higher TN and bromide content produced more toxic N-DBPs, mainly dichloroacetonitrile and dibromoacetonitrile

Assessing the municipal service quality of residential neighborhoods based on SERVQUAL, AHP and Citizen's Score Card: A case study of Dhaka North City Corporation area, Bangladesh

Rapid urban population growth stimulates the challenges of city government authorities in providing the municipal services adequately considering the citizen's demand. While the gap persists between the service provision and citizen's perception on it, the quality of life of cities may deteriorate due to psychological dissatisfaction of dwellers with urban services. Hence the evaluation of the urban service quality from the citizen's perspective and accordingly addressing the gap is necessary for sustainable urban management. This study shows a common framework incorporating SERVQUAL, Analytical Hierarchy Process (AHP) and Citizen's Score Card to define the quality of municipal services spatially and functionally based on the satisfaction of citizens. The items under the dimensions of SERVQUAL and the weightages of each dimension were set through literature review and expert opinion. Dhaka, the only megacity of Bangladesh is experiencing an impetuous growth towards its northern portion and Dhaka North City Corporation (DNCC) is the responsible authority to supply the municipal facilities within this area. Nine residential neighborhoods having homogeneous characteristics in terms of population density, residential land use, built up area and income level within the jurisdictional area of DNCC were selected to collect the data. The data were collected through household questionnaire survey using stratified random sampling technique where people responded for each SERVQUAL questions and scored the facilities provided by the DNCC. The result shows citizens are moderately satisfied (63.3%) with municipal services aggregately. To meet the demand of dwellers, the city government authority should be more functional, reliable and participatory and be equipped with qualified manpower and facilities. Despite the locational characteristics are uniform among the case areas, Ward 3, Ward 4 and Ward 31 are in unprivileged state in terms of municipal services. The facilities of public toilet, parking and disaster management activities performed by DNCC are commonly in unsatisfactory state in all areas that require special attention from the authority. Based on the findings, it could be stated that where the city government authority is roughly unsusceptible to meet the demand of the existing population, the enormous population growth within urban areas could affect the life quality poorly. Therefore this paper would fetch a course where the deficiency on urban services would be evaluated under a common arena considering the psychological aspect of citizen, thereby priority interventions could be ascertained for enhancing the life quality of urban areas

Shashthosheba: Dissecting Perception of Bangladeshi People towards Telemedicine Apps through the Lens of Features of the Apps

Bangladesh, a developing country with a large and dense population, has recently seen significant economic as well as technological developments. The growth of technology has resulted in a dramatic increase in the number of smartphone users in Bangladesh, and as such, mobile apps have become an increasingly important part of peoples' life, even encompassing healthcare services. However, the apps used in healthcare (telemedicine to be specific) in Bangladesh are yet to be studied from the perspective of their features as per the voices of the users as well as service providers. Therefore, in this study, we focus on the features of the telemedicine apps used in Bangladesh. First, we evaluated the present status of existing telemedicine apps in Bangladesh, as well as their benefits and drawbacks in the context of HCI. We analyzed publicly accessible reviews of several Bangladeshi telemedicine apps (N = 14) to evaluate the user impressions. Additionally, to ascertain the public opinion of these apps, we performed a survey in which the patients (N = 87) participated willingly. Our analysis of the collected opinions reveals what users experience, what they appreciate, and what they are concerned about when they use telemedicine apps. Additionally, our study demonstrates what users expect from telemedicine apps, independent of their past experience. Finally, we explore how to address the issues we discovered and how telemedicine may be used to effectively offer healthcare services throughout the country. To the best of our knowledge, this study is the first to analyze the perception of the people of Bangladesh towards telemedicine apps from the perspective of features of the apps.Comment: 12 page

Penyerapan alumni jurusan ilmu perpustakaan UIN Syarif Hidayatullah Jakata di pasar kerja

xi, 67 hlm.; ilus.; 30 c

Penyerapan alumni jurusan ilmu perpustakaan UIN Syarif Hidayatullah Jakata di pasar kerja

xi, 67 hlm.; ilus.; 30 c

A relationship between phages and organic carbon in wastewater treatment plant effluents

With stringent effluent requirements and the implementation of new processes for micropollutant removal, it is increasingly important for wastewater treatment plants (WWTPs) to understand the factors affecting effluent quality. Phages (viruses infecting prokaryotes) are abundant in the biological treatment processes. They can contribute to organic carbon in the treated effluent both because they are organic in nature and occur in the effluent and because they cause lysis of microorganisms. Today very little is known about the effects of phages on effluent quality. The goal of this study was, therefore, to determine the relationship between phages and organic carbon in WWTP effluents. We also examined the diversity, taxonomy, and host-association of DNA phages using metagenomics. Effluent samples were collected from four WWTPs treating municipal wastewater. Significant differences in both organic carbon and virus-like particle concentrations were observed between the plants and there was a linear relationship between the two parameters. The phage communities were diverse with many members being taxonomically unclassified. Putative hosts were dominated by bacteria known to be abundant in activated sludge systems such as Comamonadaceae. The composition of phages differed between the WWTPs, suggesting that local conditions shape the communities. Overall, our findings suggest that the abundance and composition of phages are related to effluent quality. Thus, there is a need for further research clarifying the association between phage dynamics and WWTP function