New journal article published in Science of the Total Environment

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Written by Bethany Fox, Research Associate in Centre for Research in Biosciences (CRIB)

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.

Sensor boat survey and water quality monitoring of the Hooghly River (Ganga) in Kolkata, West Bengal, India.

Biological filtration using different porosities of ceramic media

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By Sadie Hadrill (MRes Student)

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.

Biofilter maturation

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.

Figure 1. Laboratory scale biofilters containing three different types of clay media, varying in porosity: A) Low porosity, B) Medium porosity and C) High porosity.

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.

Figure 2. Laboratory scale biofilter columns containing ceramic media (A), connected to a four-channel peristaltic pump (B) and circulation tanks (25 L) containing mains tap water (C).

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.

Healthy Waters Research Cluster sets sights on four research challenges

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When it comes to healthy water there is no shortage of challenges – indeed the difficulty is often in finding sufficient focus to not feel paralysed by the extent of problems. In April, UWE Bristol’s Healthy Water Research Cluster did just that. On a Friday afternoon, in a room kitted out for the training of primary educators – complete with thrones and creative mobiles – researchers from across disciplines as varied as engineering, biosciences, creative industries, science communication, economics and supply chain management came together to identify research priorities for the cluster.

Over the coming months, UWE Bristol’s Healthy Water research cluster will be developing the following project ideas:

Managing Water Resources through Smart Landscapes

Data is collected for water systems all over the world by different organisations and for different purposes. The challenge is that these data sets are not integrated and not always accessible – even within a single country let alone across borders. As technology moves on there are additional challenges around integrating data from old technology with that of the new. Imagine having integrated data sets at a landscape level, where industry, government, researchers and communities can interact with data to improve ecosystem resilience, exchange knowledge and engage communities in their local environment.

Management of water quality through community-based value chains in water technology

Innovation in water treatment technologies is important but not enough – we also need to create localised production systems that are sustainable and take into account the whole life cost of the process, including maintenance, final disposal, recycling or reuse.  This workstream focuses on articulating models for creating affordable community-based value chains, that build on the use of local, readily available materials and expertise, employing water technologies such as ceramic filters, rainwater harvesting systems and gravity supply schemes.

Development of rapid water quality assessment technologies

New advances in water quality monitoring strategies are urgently needed for both water catchments and drinking water supplies. Improved temporal and spatial water quality data will require new and multiple real-time monitoring technologies and approaches that enable rapid chemical and biological assessment at a single point-source or through an integrated catchment network. Such data is imperative if effective water quality management frameworks are to be implemented and realised.

Scalable and sustainable water treatment solutions and technologies

Safe water in the context wastewater or drinking water is essential in minimising potential contaminants and pollutants from entering water systems or reducing the possibility of disease in humans. Many current treatment solutions or technologies are centralised in nature, where a large-scale facility will treat vast volumes of water across a large area and then distribute throughout extensive networks where necessary. This is a costly approach to build and maintain and is unattainable for some communities, such as rural communities or communities in low-income countries. Developing scalable and sustainable solutions that are decentralised and can be easily maintained by communities, with minimal resource requirements are key to ensuring waters are reliably treated to a high standard.

The Healthy Waters research cluster is looking to engage with people interested in these projects – other researchers, industry, government agencies, NGOs, community organisations and other stakeholders. Please do get in touch research@uwe.ac.uk for more information.

Sustainable Solutions to Water Quality Challenges in Rural Uganda

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Written by Chad Staddon, Professor of Resource Economies 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.

To improve the microbiological quality of stored drinking water, ceramic pot filters (CPFs) may be a robust point-of-use technological solution. Through a combination of mechanisms including ultrafiltration, adsorption and biofilm metabolism CPFs have been demonstrated to be effective at removing >99% of protozoa and 90-99% of bacteria. CPFs are associated with a 60-70% reduction in diarrheal disease incidence reported by users in some studies.

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.

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