Fundamental studies of anaerobic biosorption in wastewater treatment

The potential for sorption of soluble organic matter on anaerobic biomass is currently under investigation by the author and coworkers at Iowa State University. Biosorption is defined as the uptake or accumulation of particulates and chemicals by microbial biomass. The anaerobic biosorption process utilizes the sorption capabilities of active biomass for the treatment of wastewater. Biosorption is a rapid process. About 40% removal of organic matter was obtained in only 15 minutes after the substrate was brought in contact with the biomass;This dissertation presents the results of preliminary investigations on the effects of various factors on the biosorption process. The primary objective of this research was to determine the applicability of anaerobic biomass as a potential sorbent for organic matter and to quantify the results in terms of isotherms. The effects of mixing times, temperature, substrate concentration, biomass concentration, and granular biomass particle size were also studied;Anaerobic biomass was grown at 35°C in 10-liter source reactors, operated as anaerobic sequencing batch reactors (ASBR). Biosorption experiments were performed with active biomass in two liter batch reactors on a synthetic milk waste. The particle size distributions of the granular biomass were determined using an Automatic Image Analysis system. Temperature studies were significant. Better removals were obtained at higher temperature than at lower temperature. It was observed that wastes at temperatures as low as 7°C could be treated without the application of external heat;Higher removals were obtained with the small granular biomass than with the large granules. Increasing the biomass concentration resulted in a significant increase in the percentage removal of organic matter. Another method of improving biosorption was to operate a number of sorption reactors in series. High overall COD removals were obtained in a series of three reactors. The results were expressed in terms of adsorption isotherms. The data conformed well to both the Freundlich and the Langmuir adsorption models

Protocol to develop sustainable day care for children aged 1-4 years in disadvantaged urban communities in Dhaka, Bangladesh

INTRODUCTION: Lack of safe, stimulating and health-promoting environments for children under-5 hinders their physical, social and cognitive development, known as early childhood development (ECD). Improving ECD impacts on children, and can improve educational attainment for girls, who often care for younger siblings, and employment prospects for mothers. Developing and evaluating the impacts of ECD programmes within childcare needs to assess a range of social, health, educational and economic impacts, including women's empowerment.Children living in slums are at high risk of poor early development and holistic, sustainable interventions are needed to address ECD in these contexts. This study will be undertaken in Dhaka, Bangladesh, a city where over 8.5 million inhabitants live in slums. In collaboration with government, non-governmental organisations and communities, we are developing and testing a sustainable day-care model for low-income communities in Dhaka. METHODOLOGY AND ANALYSIS: A sequential mixed methods approach is being used in the study, with qualitative work exploring quantitative findings. Two hundred households with children under-5 will be surveyed to determine day-care needs and to assess ECD (parent-reported and direct assessment). The feasibility of four ECD measuring tools Caregiver-Reported Early Development Index, Measuring Early Learning Quality and Outcomes, The Early Human Capability Index and International Development and Early Learning Assessment will be assessed quantitatively and qualitatively. Qualitative methods will help understand demand and perceptions of day care while mothers work. Participatory action research will be used to develop a locally appropriate and potentially sustainable model of day care for under-5 children. A ward in the south of Dhaka has been selected for the study as this typifies communities with slum and non-slum households living next to each other, allowing us to explore potential for better-off household to subsidise day care for poorer households. ETHICS AND DISSEMINATION: Findings will be published and inform decision makers at the national, regional and the local actors in order to embed the study into the policy and practice on childcare and ECD. Ethical approvals for this study were obtained from the School of Medicine Research Ethics Committee at the Faculty of Medicine and Health at the University of Leeds (ref: MREC16-106) and the Bangladesh Medical Research Council (ref: BMRCAIREC/20 I 6-20 I 9 I 250)

Addressing unintentional exclusion of vulnerable and mobile households in traditional surveys in Kathmandu, Dhaka and Hanoi : a mixed methods feasibility study

The methods used in low- and middle-income countries’ (LMICs) household surveys have not changed in four decades; however, LMIC societies have changed substantially and now face unprecedented rates of urbanization and urbanization of poverty. This mismatch may result in unintentional exclusion of vulnerable and mobile urban populations. We compare three survey method innovations with standard survey methods in Kathmandu, Dhaka, and Hanoi and summarize feasibility of our innovative methods in terms of time, cost, skill requirements, and experiences. We used descriptive statistics and regression techniques to compare respondent characteristics in samples drawn with innovative versus standard survey designs and household definitions, adjusting for sample probability weights and clustering. Feasibility of innovative methods was evaluated using a thematic framework analysis of focus group discussions with survey field staff, and via survey planner budgets. We found that a common household definition excluded single adults (46.9%) and migrant-headed households (6.7%), as well as non-married (8.5%), unemployed (10.5%), disabled (9.3%), and studying adults (14.3%). Further, standard two-stage sampling resulted in fewer single adult and non-family households than an innovative area-microcensus design; however, two-stage sampling resulted in more tent and shack dwellers. Our survey innovations provided good value for money, and field staff experiences were neutral or positive. Staff recommended streamlining field tools and pairing technical and survey content experts during fieldwork. This evidence of exclusion of vulnerable and mobile urban populations in LMIC household surveys is deeply concerning and underscores the need to modernize survey methods and practices

Surveys for Urban Equity

This dataset contains results and documentation from three cross-sectional urban household surveys done in Kathmandu (Nepal), Dhaka (Bangladesh) and Hanoi (Vietnam) in 2017 and 2018. The surveys primarily aimed to test the feasibility of using new urban household survey methods that try to better cover/capture informal/slum settlements using sampling frame data generated from random forest models that incorporate census data (which is often outdated and inaccurate) with multiple remotely-sensed covariates, such as urbanisation and infrastructure data. Additionally, the surveys also aimed to gather data on a range of topics including many that are not commonly collected in household surveys, particularly of urban areas: A) basic socio-demographic details of household members, B) household characteristics, assets, income and expenses, C) household migration and social capital, D) household member injury and injury related death, and, for one individual per household, E) migration, social capital and depression/mental health. See the "Readme - dataset file descriptions.docx” file for a description of all files and datasets available, plus additional relevant references

Fundamental studies of anaerobic biosorption in wastewater treatment

The potential for sorption of soluble organic matter on anaerobic biomass is currently under investigation by the author and coworkers at Iowa State University. Biosorption is defined as the uptake or accumulation of particulates and chemicals by microbial biomass. The anaerobic biosorption process utilizes the sorption capabilities of active biomass for the treatment of wastewater. Biosorption is a rapid process. About 40% removal of organic matter was obtained in only 15 minutes after the substrate was brought in contact with the biomass;This dissertation presents the results of preliminary investigations on the effects of various factors on the biosorption process. The primary objective of this research was to determine the applicability of anaerobic biomass as a potential sorbent for organic matter and to quantify the results in terms of isotherms. The effects of mixing times, temperature, substrate concentration, biomass concentration, and granular biomass particle size were also studied;Anaerobic biomass was grown at 35°C in 10-liter source reactors, operated as anaerobic sequencing batch reactors (ASBR). Biosorption experiments were performed with active biomass in two liter batch reactors on a synthetic milk waste. The particle size distributions of the granular biomass were determined using an Automatic Image Analysis system. Temperature studies were significant. Better removals were obtained at higher temperature than at lower temperature. It was observed that wastes at temperatures as low as 7°C could be treated without the application of external heat;Higher removals were obtained with the small granular biomass than with the large granules. Increasing the biomass concentration resulted in a significant increase in the percentage removal of organic matter. Another method of improving biosorption was to operate a number of sorption reactors in series. High overall COD removals were obtained in a series of three reactors. The results were expressed in terms of adsorption isotherms. The data conformed well to both the Freundlich and the Langmuir adsorption models.</p

Fundamentals of wastewater treatment and engineering

Fundamentals of Wastewater Treatment and Engineering introduces readers to the essential concepts of wastewater treatment, as well as the engineering design of unit processes for the sustainable treatment of municipal wastewater. Filling the need for a textbook focused on wastewater, it first covers history, current practices, emerging concerns, and pertinent regulations and then examines the basic principles of reaction kinetics, reactor design, and environmental microbiology, along with natural purification processes. The text also details the design of unit processes for primary, secondary, and advanced treatment as well as solids processing and removal. Using detailed calculations, it discusses energy production from wastewater

STRATEGIES FOR IMPROVING ENVIRONMENTAL IMPACT ASSESSMENT PROCESS IN PAKISTAN

Pakistan has recently introduced the Environmental 1m pact Assessment (EIA) process in developmental schemes through out the country. An ElA strategy has been presented in this paper for future developmental work to improve environmental situation in the country. In this strategy emphasis is given to public participation and consultation in decision-making process, monitoring and auditing of environmental projects.Public involvement in E/A process is an effective technique for improving decision-making. Different proposals for screening, scoping, initial environmental examination (IEE), E/A report preparation and mitigation measures for new project activities are discussed in detail. This proposed E/A system has unique characteristics, based on Pakistani socioeconomic, and cultural approach and its implementation in a proper way can be compared well with any EIA system in neighboring countries as well as at global level

Unionized Acetate Degradation at 45ºC Anaerobic Digestion: Kinetics and Inhibition

This study demonstrated the degradation of unionized acetate in anaerobic digestion at 45ºC through the identification of kinetics and inhibition parameters. The kinetic parameters, Ks and rmax, were determined using Monod-based model for three different conditions, namely uninhibited, inhibited, and systems with high substrate condition. The Ks values for uninhibited condition were in the range of 0.124 to 0.191 mg/L as unionized HAc. Ks value of inhibited condition were at 0.027 mg/L as unionized HAc. Ks values for systems with high substrate condition were found to be in the range of 0.237 to 0.279 mg/L as unionized HAc. As for rmax, a 35ºC anaerobic digestion system showed the highest value at 0.166 mg/L/day – greater than the values of all 45ºC systems under all experimental conditions. Additionally, the inhibition parameter KI was also determined using the Michaelis-Menten model. The parameter was determined for inhibitory conditions resulting from high free NH3 content. The inhibition type was uncompetitive with KI value of 0.072 mg/L as unionized HAc. The outcomes suggested that the methanogens responsible for the digestion process at 45ºC were thermo-tolerant acetate-utilizing methanogens of Methanosarcinaceae species, and the system will be totally inhibited with the presence of high free NH3 content. © 2019, HARD Publishing Company. All rights reserved

Temperature phased anaerobic digestion at the intermediate zone of 45 ℃ : performances, stability and pathogen deactivation

Temperature phased anaerobic digestion (TPAD) systems with conventional sequences (first stage of 55 ℃ and second stage of 35 ℃) have been widely studied. However, very limited studies were available on TPAD system with the first stage operated at the intermediate zone of 45 °C, mainly due to the notion that limited microbial activity occurs within this zone. The objective of this research was to evaluate the performance, stability and the capability of 45 °C TPAD in producing class A biosolids, in comparison to a conventional TPAD. Four combinations of TPAD systems were studied, 45 ℃ TPAD 2.5/10 (1st stage solids retention time (SRT) 2.5 days/2nd stage SRT 10 days), 45 ℃ TPAD 7.5/10, 55 ℃ TPAD 2.5/10 and 55 ℃ TPAD 7.5/10. Among all, 45 ℃ TPAD 7.5/10 was found to have the best performances, attributed to its high volatile solids (VS) destruction (58%), minimal acetate accumulation (127 mg/L), high methane yield (0.58 m3 CH4/kg VS removed), high COD destruction solid COD (sCOD; 74% and total COD (tCOD) 54%) and minimal free NH3 content (67.5 mg/L). As for stability, stable pH distribution, high alkalinity content and low VFA to alkalinity ratio, indicated a well-buffered system. Additionally, the system had also able to produce class A biosolids. Therefore, proved that TPAD system operated at the intermediate zone of 45 ℃ can perform better than the conventional TPAD, hence, highlighting its economic advantage