Role of wetlands in wastewater purification

Role of wetlands in wastewater purificatio

Biodegradation of Estrogenic Compounds and Its Enhancement in a Membrane Bioreactor – Research Category III, Water Quality

This was a project, which investigated enhancement removal of estrogenic activities in activated sludge.In the project, we investigated enhancement removal of estrogenic activities in activated sludge. These activities are caused by natural and synthetic substances that mimic the effect of the human hormone estrogen and they potentially can disrupt the endocrine systems of exposed species and the reproductive systems of aquatic fauna. Human and animal wastes are a source of natural and synthetic estrogens to the environment since only a fraction is removed in conventional wastewater treatment. A yeast-based assay developed previously was modified to detect the estrogenic activity in wastewater samples. Using the assay, it was possible to quantify estrogenic activity in range equivalent to between approximately 100ng/L to 100g/L of the female hormone 17-estradiol (E2), with sensitivity as low as 0.03ngE2/L. The assay is therefore sensitive to the concentrations of environmental estrogens typically found in wastewater and the new assay may be a useful tool for screening for estrogenic activity. Compared to existing chemical analytical methods, the new test is simpler and covers a wider range of compounds. This is important because by-products of some of the influent estrogens are also active estrogens. For example, E2 is metabolized to estrone and estriol, which are estrogenic. Monitoring the removal of only a few substances may underestimate the estrogenic properties of treatment plant effluents and solids disposed of into the environment. Further experiments were carried out to determine the removal of estrogenic activity from water. Results show that the presence of activated sludge enhances removal of total estrogenic activity by at least 40% within 10-15 days

Relationship between water quality and physical conditions of domestic storage tanks supplied by a water utility in a rapidly growing city

This is a research paper discussing findings of domestic water storage tanks are commonly used in urban centres of developing countries such as Uganda to enable reliable access to water.Domestic water storage tanks are commonly used in urban centres of developing countries such as Uganda to enable reliable access to water. However, little work has been done on the conditions of domestic water storage tanks since it is assumed that water received meets the required standards and guidelines for drinking water. In 2015, over 80% of the water quality complaints raised by water utility customers in Kampala were about water from storage tanks. In this study we assessed water quality in, and conditions of, domestic storage tanks, for customers supplied by a water utility from March – August 2017 in Kampala, Uganda. Longitudinal assessment of 372 storage tanks in 6 sampled wards involved a minimum of 6 samples collected from each site in both wet and dry months of 2017. A set of guiding questions was used to establish tank conditions, with a 'yes' or 'no' response and a range of 'low' to 'critical' risk ratings. The study showed that there were three main types of storage tanks: plastic (88%), concrete (7%), and metal (5%). Of these tanks, 84% were elevated, 41% were less than 5 years old, 69% were not cleaned annually, and 88% were covered. There was a statistically significant relationship (p < 0.05) between tank physical conditions and quality of stored water. Wards with unplanned and industrial settlements had the highest number of tanks with contaminated water. The study therefore revealed that the physical conditions and management of domestic water storage tanks have an effect on water quality. This is important information for a water utility as it means that it is not enough to supply safe water if the quality may deteriorate upon storage at the consumer premises. A routine inspection checklist and consumer guidelines for domestic storage tank management are proposed

Calibrating an optimal condition model for solar water disinfection in peri-urban household water treatment in Kampala, Uganda

This study investigated the efficacy of the SODIS treatment method in Uganda and determined the optimal condition for effective disinfection.In low income settlements where the quality of drinking water is highly contaminated due to poor hygienic practices at community and household levels, there is need for appropriate, simple, affordable and environmentally sustainable household water treatment technology. Solar water disinfection (SODIS) that utilizes both the thermal and ultra-violet effect of solar radiation to disinfect water can be used to treat small quantities of water at household level to improve its bacteriological quality for drinking purposes. This study investigated the efficacy of the SODIS treatment method in Uganda and determined the optimal condition for effective disinfection. Results of raw water samples from the study area showed deterioration in bacteriological quality of water moved from source to the household; from 3 to 36 cfu/100 mL for tap water and 75 to 126 cfu/100 mL for spring water, using thermotolerant coliforms (TTCs) as indicator microorganisms. SODIS experiments showed over 99.9% inactivation of TTCs in 6 h of exposure, with a threshold temperature of 39.5± 0.7 WC at about 12:00 noon, in the sun during a clear sunny day. A mathematical optimal condition model for effective disinfection has been calibrated to predict the decline of the number of viable microorganisms over time

Household drinking water characteristics in a peri-urban community: the case of Kifumbira Zone, Kampala, Uganda

A study to determine the drinking water quality improvement practises at household level was undertaken in Kifumbira Zone, a Kampala peri-urban area, Uganda. The socio-economic conditions of 150 households were identified using questionnaires and in-depth interviews. Solar water disinfection (SODIS) was introduced to 10 households and water from their boiled drinking water and SODIS treated water was monitored for three months. The social survey indicated that boiling was the most common method applied to improve the drinking water quality – mainly using charcoal and electricity. 65% of the respondent households boiled their drinking water, while the rest consumed it unboiled due to the high cost of charcoal. The raw water sources exhibited microbiological contamination as evidenced by the presence of thermotolerant coliforms and high risk scores on the sanitary inspections conducted. There was a statistically significant difference (p<0.05; n=15) in the mean count of thermotolerant coliforms for boiled and SODIS treated water

Amplifying local voices to reduce failure in the water, sanitation and hygiene sector

This is a poster briefWASH endeavours regularly fail. Sometimes this means that entire programmes do not achieve their stated aims, sometimes these failures are setbacks which can be rectified with sufficient reflection and action. This research aimed to develop an evidence base of how and why field-based WASH professionals in four sub-Saharan African countries believe failures occur, their experiences when sharing and discussing them within their organisations, and how they believe a culture conducive to publicly sharing and learning from failures could be nurtured

Application of a yeast-based assay protocol developed to monitor total oestrogenic activity induced by 17β-oestradiol in activated sludge supernatants from batch experiments

This is a research paper on Application of a yeast-based assay protocol developed to monitor total oestrogenic activity induced by 17β-oestradiol in activated sludge supernatants from batch experimentsBatch experiments were carried out with activated sludge from laboratory reactors and a full-scale treatment plant spiked with 17β-oestradiol (E2). An oestrogen-sensitive yeast-based assay protocol, described in detail in a related publication, was used to measure reduction of E2-induced total oestrogenic activity from the sludge supernatant over a 15 d period after which the sludge was re-spiked to check for possible enhancement of reduction by pre-exposed sludge during an additional 15 d period. The reduction was generally improved by increasing sludge solids concentrations and by continuous mixing. For a 100 ngE2/ℓ spike there was >40% reduction of oestrogenic activity within 15 d, which improved to >70% by pre-exposing the sludge. The oestrogenic activity produced by a dose of 100 μgE2/ℓ was readily removed by most sludges within 15 d. How¬ever, re-spiking the activated sludge with the same E2 concentration caused some sludges to lose reduction capacity

Developing a yeast-based assay protocol to monitor total oestrogenic activity induced by 17β-oestradiol in activated sludge supernatants from batch experiments

This is a research paper on developing a yeast-based assay protocol to monitor total oestrogenic activity induced by 17β-oestradiol in activated sludge supernatants from batch experimentsA yeast-based assay protocol developed for detecting oestrogenic activity in activated sludge (AS) supernatant is described. The protocol used Saccharomyces cerevisiae construct RMY/ER-ERE with human oestrogen receptor (ERα) and lacZ reporter genes, and was developed by modifying existing assays for use with AS samples from batch experiments. The method was able to detect total oestrogenic activity (without prior extraction) in supernatants of AS spiked with 17β-oestra¬diol (E2) with a detection limit of 0.03 ngE2-equivalent/ℓ and an overall quantification limit of 100 ngE2-equivalent/ℓ. Mean E2-induced oestrogenic activity recoveries of >56% were obtained from the spiked samples

Biodegradation of estrogenic compounds and its enhancement in a membrane bioreactor

In the project, we investigated enhancement removal of estrogenic activities in activated sludge. These activities are caused by natural and synthetic substances that mimic the effect of the human hormone estrogen and they potentially can disrupt the endocrine systems of exposed species and the reproductive systems of aquatic fauna. Human and animal wastes are a source of natural and synthetic estrogens to the environment since only a fraction is removed in conventional wastewater treatment. A yeast-based assay developed previously was modified to detect the estrogenic activity in wastewater samples. Using the assay, it was possible to quantify estrogenic activity in range equivalent to between approximately 100ng/L to 100µg/L of the female hormone 17-β estradiol (E2), with sensitivity as low as 0.03ngE2/L. The assay is therefore sensitive to the concentrations of environmental estrogens typically found in wastewater and the new assay may be a useful tool for screening for estrogenic activity. Compared to existing chemical analytical methods, the new test is simpler and covers a wider range of compounds. This is important because by-products of some of the influent estrogens are also active estrogens. For example, E2 is metabolized to estrone and estriol, which are estrogenic. Monitoring the removal of only a few substances may underestimate the estrogenic properties of treatment plant effluents and solids disposed of into the environment. Further experiments were carried out to determine the removal of estrogenic activity from water. Results show that the presence of activated sludge enhances removal of total estrogenic activity by at least 40% within 10-15 days

Biodegradation of estrogenic compounds and its enhancement in a membrane bioreactor

In the project, we investigated enhancement removal of estrogenic activities in activated sludge. These activities are caused by natural and synthetic substances that mimic the effect of the human hormone estrogen and they potentially can disrupt the endocrine systems of exposed species and the reproductive systems of aquatic fauna. Human and animal wastes are a source of natural and synthetic estrogens to the environment since only a fraction is removed in conventional wastewater treatment. A yeast-based assay developed previously was modified to detect the estrogenic activity in wastewater samples. Using the assay, it was possible to quantify estrogenic activity in range equivalent to between approximately 100ng/L to 100µg/L of the female hormone 17-β estradiol (E2), with sensitivity as low as 0.03ngE2/L. The assay is therefore sensitive to the concentrations of environmental estrogens typically found in wastewater and the new assay may be a useful tool for screening for estrogenic activity. Compared to existing chemical analytical methods, the new test is simpler and covers a wider range of compounds. This is important because by-products of some of the influent estrogens are also active estrogens. For example, E2 is metabolized to estrone and estriol, which are estrogenic. Monitoring the removal of only a few substances may underestimate the estrogenic properties of treatment plant effluents and solids disposed of into the environment. Further experiments were carried out to determine the removal of estrogenic activity from water. Results show that the presence of activated sludge enhances removal of total estrogenic activity by at least 40% within 10-15 days