A new paper has been published in Science of the Total Environment (STOTEN), “A case study: The deployment of a novel in situ fluorimeter for monitoring biological contamination within the urban surface waters of Kolkata, India”.
This paper details the deployment of a novel in situ fluorescence sensor in the urban surface waters of Kolkata. The case study demonstrates the benefit of this technology with recent advances in understanding and technological capability. Using the new sensor, developed by our technology partner Chelsea Technologies Ltd., the team were able to identify a blackwater contamination event in the Hooghly River (Ganga) in Kolkata, India. The team also conclude that the use of this technology would provide information regarding biological water quality in situ and in real-time, important information which is often missing from our current monitoring practices due limited to time consuming and expensive sampling surveys.
This paper is an output from the NERC-DST India-UK Water Quality project which focused on the development and implementation of technologies for improved water quality. Within this project, UWE has been in partnership with Professor Tapan K Dutta and his team at the Bose Institute in Kolkata alongside multiple UK technology partners.
Freshwater is essential for life on Earth, and the role of freshwater is fundamental to society and for maintaining healthy ecosystems. Biological filtration is a sustainable biotechnology used to remediate biological and chemical contaminants within water. This is performed by establishing polymicrobial biofilms (diverse microbial communities) on a granular substrate, that can be housed within a column, here referred to as a biofilter. Biofilters develop efficient sorptive (attachment) capacity within diverse microbial communities of biofilms.
Filtration media has come in many forms prior to recent experimentation including sand, charcoal and granular activated carbon. Different filter media properties, including permeability, surface area and porosity, can determine the performance of the biofilter. As such, practical knowledge is needed regarding the impact of the type of filter media used. In this example we used ceramic media, more specifically terracotta clay, varying in porosity as described in the previous blog post. The team at UWE’s Centre for Print Research (CFPR) created ceramic media of low, medium and high porosities to determine the impact of porosity on the biofilter systems.
The three variations of ceramic media were equally distributed into three individual filter columns (9 filters in total) and connected to 25 L tanks containing tap water. To aid the beginning stages of biofilm maturation, the water tanks were inoculated with pond water to introduce environmental organisms.
Over four weeks of biofilm maturation, the biofilters were monitored weekly for nutrient concentrations (such as phosphates and nitrates) and bacteria. Samples were extracted from both the filter media and the circulation water for analysis.
An investigation of porosity of media and pathogen removal
Once the biofilters had undergone maturation, the experiment investigated the removal of Escherichia coli (E. coli)and Enterococci, both are bacterial indicators of faecal contamination. Over a 24-hour period pond water was circulated through the biofilters containing the different porosity ceramic media. Samples of the circulated pond water were collected every three hours and analysed for the presence of the E. coli and Enterococci.
Preliminary results indicated a decline in both E. coli and Enterococci recovered from samples taken over a 24-hour period. However, initial findings suggest that the ceramic media porosity has little impact on E. coli and Enterococci removal as there was little difference between the bacteria counts for the three different porosities of ceramic media.
Further experimental work is ongoing to explore pathogen removal in more detail and to determine if the size of the ceramic media (e.g. smaller ceramic beads) impacts the performance of the biofilter.
Written by Bethany Fox, Research Associate in Centre for Research in Biosciences (CRIB)
Access to safe water should be a basic right for all. Turning on a tap to drink from seems so natural to many of us, but with 1 in 3 people around the world not having access to safe drinking water, there is still much to be done. The COVID-19 pandemic has only further highlighted the importance of clean water, sanitation and good hygiene, with those without access to water being disproportionately vulnerable.
Frank Water is a Bristol-based water charity that began life in 2005 as a social enterprise which donated all profits to an NGO in India for water projects. It is now a registered charity providing safe water, sanitation and good hygiene to communities in India and Nepal, helping almost 500,000 people to date. Frank also works within the UK providing education regarding sustainable approaches to water.
UWE Bristol has an ongoing relationship with Frank Water and have been actively working together on a NERC-DST India-UK Water Quality project for the past 4 years. This project focused on the development and implementation of technologies for improved water quality.
One of the key aims within this project was to provide a low-cost small-scale sustainable technology to treat biologically contaminated stored water, such as that from a borehole or harvested rainwater. Working with Frank Water, Indian NGO Bala Vikasa and technology partner Centrego, we have begun the deployment of two prototype systems: one in a government school in Hyderabad, Telangana, to ensure a safe supply of drinking water for the school children and staff; and, a second system in Massampally, a remote tribal village in the Warangal district of Telangana, where the systems are treating water from a contaminated open well to provide a source of safe drinking water to the village’s 33 households which rely on this well for all their water, sanitation and hygiene needs.
Having seen first-hand the amazing work undertaken by Frank Water Projects and their collaborators in India, UWE researcher Dr Bethany Fox has chosen to fundraise for Frank Water by running the Bristol Half Marathon in September 2022. This will be Bethany’s first half marathon but she hopes to raise awareness and money to support Frank Water and the amazing work they do.
In the latest issue of Craft Magazine they look at the work of Potters for Peace (PFP) ‘a non-profit, social justice organization focused on using clay based solutions to address the problems of poverty.’ The amazing work PFP have implemented and published around locally made ceramic water filters has been a big inspiration for us here at UWE working on Heathy Waters. The literature produced by PFP has been a useful resource to start our own research especially around the use of burn-out material to be added to clay to increase precocity. Where PFP have developed a process where the ceramic filters are produced with a mould and a hydraulic press, we are looking at the already existing skills and process of local potter’s to hand building and pit fire water filter, like that of the craft potters in Kisoro Uganda, who currently produce ceramic cooking stoves.
Our initial ceramic tests have been focused on producing ceramic beads of different porosity to work as a medium for a biofilm to grow within a water filter. We have looked at two processes for these beads, extrusion, a well-established industrial process, and a organic foam impregnating method in which we laser cut compressed cellulose sponge that is then expanded in water then dipped in a ceramic slurry.
Our next tests will be looking at producing a hand build ceramic water filter using a basic hand building technique known as coiling, which is more in line with the hand building process of the Ugandan potters. The pots will be made from terracotta clay with sawdust added in different percentages they will then be tested to establish the balance between increasing precocity to reduce time taken for the water to pass through the filter but still maintain a high efficacy of removing bacteria and pathogens.
Written by Chad Staddon, Professor of ResourceEconomies and Policy.
A lack of access to safe, piped water services in many parts of the world means that alternative water supplies, such as rainwater harvesting (RWH), are often all that is available. However some studies have shown that RWH may pose a health risk because of its potential to carry microbial pathogens through wet deposition (bonding of chemicals in the air before hitting the roof), transit via the catchment area (usually a rooftop), drainage gutters and pipes, and the residence time in the storage tank itself. Indeed, water quality testing undertaken by a UWE Bristol team in southwestern Uganda in 2019 suggested that up to 50% of water samples from RWH systems could be contaminated in excess of WHO limits.
In 2018 and 2019 UWE Bristol staff and students worked to better understand the extent of the water quality challenge associated with RWH and to options assess possible solutions including granular media, solar disinfection and ceramic pot filters. Now, the UWE Bristol Healthy Waters team, including Chad Staddon, Tavs Jorgenson and Jiseon You, is working to determine if CPFs can be manufactured in accordance with appropriate technology principles stipulating that technologies should be locally reproducible and maintainable with essentially existing skills and resources. The team aims to develop a trial for locally produced CPFs using existing ceramics making processes including open pit firing during 2022. If successful the team hopes to support and encourage the scale up of production by local producer groups, enterprises or cooperatives, thus addressing capacity gaps identified in earlier research.
In England, no river achieves good chemical status, only 14% achieve good ecological status and none achieve both good chemical and ecological status according to the European Water Framework Directive. The deteriorating quality of our river systems is a result of pollution runoff events from storm water discharge, sewage discharge and land mismanagement. Pollution from sewage discharge and land misuse (e.g. agricultural chemical runoff) can result in diminishing water quality through increased nutrient availability in rivers. The increased availability of nutrients in rivers can lead to algal blooms and eutrophication events. Eutrophication events negatively impact the quality of freshwater systems as light penetration becomes limited as sheets of algae cover surfaces. This then leads to reduced oxygen availability, which greatly impacts the microbial and aquatic life beneath the surface. The addition of excess nutrients or contaminants into our river systems can be describes as “slow violence”. Slow violence in the environment is the mid- to long-term damage or mismanagement that results in adverse effects may not always obvious: out of sight, out of mind.
An ongoing collaborative project between the Centre for Research in Biosciences, the Centre for Fine Print Research and Somerset Wildlife Trust is seeking to address slow violence in the form of how land-use can affect freshwater quality. This project intends to identify the effect of key nutrients and contaminants that are associated with excessive algal growth. This data will be integrated and interpreted in the form of traditional printmaking and experimental photographic processes. The printed outputs will investigate and respond to the relationship between land use and aquatic health. Produced artwork will be exhibited to allow for engagement with audiences and seeks to start conversations around the issue of declining water quality of our rivers and the effect of slow violence.
This multidisciplinary project is an example of interdisciplinary collaborations that are being created and nurtured as part of a new UWE Bristol-wide Healthy Waters Initiative Research Cluster. The Healthy Waters Initiative seeks to restore and enhance the health of freshwaters for people, businesses, and nature. This will be addressed through developing projects that cut across three interdisciplinary core themes: science, design and technology, and society.