Cycle 5 (2015 Deadline)
Developing exposure and toxicity data for trace organic chemicals in wastewater, biosolids, and soils
PI: Bice Martincigh (email@example.com), University of KwaZulu-Natal
U.S. Partner: Natalie Mladenov, San Diego State University
Project Dates: February 2017 - January 2019
Contemporary lifestyles and the extensive use of organic chemicals in personal care and consumer products (PCCPs) leads to the constant discharge of enormous quantities of chemical residues from industries and homes into wastewater streams and, ultimately, the environment. In contrast to heavy metals, pathways of trace organic chemicals (TOrCs) derived from manufacturing and use of PCCPs are varied in the wastewater stream . The majority of TOrCs that reach wastewater treatment plants are destroyed through treatment and sludge processing, but recalcitrant TOrCs and their metabolites can pass through the treatment process intact and partition, dependent on their physico-chemical properties, in biosolids and aqueous media. Very little is known about the fate of TOrCs in the climatic context of South Africa.
|Dr. Chris Buckley at the wastewater treatment plant at Newlands Mashu|
This team has chosen to study a set of four classes of potential pollutants: flame retardants, the broad-spectrum herbicide glyphosate (Ro undup®, ubiquitously used in the local sugarcane industry), antibiotics, and HIV anti-retrovirals. Effluents from wastewater treatment plants in the Durban area, sewage sludge, biosolids, soils from effluent-irrigated farm land, and sludge and/or biosolid-amended soils will be analyzed and characterized for the presence of these TOrCs.
This project will have access to the local DEWATS wastewater treatment plant, which allows for detailed studies on the fate of the TOrCs during their passage through the plant and subsequent agricultural areas, providing a confined and controlled environment. Comprehensive target and non-target analytical techniques will be developed to detect and quantify the four classes of compounds in the selected matrices.
Furthermore, the team will develop a simultaneous extraction and clean-up method for each chemical compound class in the above-mentioned matrices.
Summary of Recent Events
During this reporting period, four PhD students have been appointed to work on the project. These are Abdulkadir Mahmoud who is studying the flame retardants, Lerato Mollo who is investigating ARVs, Tolulope Lawrence who is working on personal care products and Eva Mary who is isolating possible compounds of value from faecal matter. Bursaries have been disbursed to Abdulkadir Mahmoud, Tolulope Lawrence and Eva Mary. Lerato Mollo has other sources of funding. Another student is due to join the project in the new year.
To date the students have undertaken their literature review, and applied for ethical clearance in order to be able to obtain some of the samples (particularly those at the DEWATS wastewater treatment plant). They have compiled lists of reagents required to undertake the project and placed orders for the standards. Some of these reagents have arrived but a number are still outstanding. The students have begun devising their analysis procedures.
Lerato Mollo and Tolulope Lawrence were able to attend the 2017 Environmental Persistent Pollutants Symposium and Workshop held in Pretoria from 2-6 October 2017. There they presented posters on their projects and also attended the three-day workshop covering sample preparation and analysis techniques for environmental pollutants. This proved very beneficial for them. Mr Abdulkadir Mahmoud spent a period of three months at the University of Birmingham receiving training on flame retardants in the laboratories of Professor Stuart Harrad. Professor Harrad is a foremost researcher on brominated flame retardants and this exchange visit forms part of the INTERWASTE programme funded by the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 734522. Again, this training proved very fruitful as Mr Mahmoud obtained valuable training in the techniques and instrumentation required for this project.
The US partner, Dr Natalie Mladenov, and some of her students visited the PI and her team in Durban from June to August 2017. The one student, Lauren Steinberg, undertook her research together with Lerato Mollo on the photolysis of ARVs in anaerobic baffled reactor (ABR) effluent. The research involved the photolysis of the antiretroviral drug, zidovudine, at a decentralized wastewater treatment system (DEWATS) in Durban that utilizes an ABR and anaerobic filter as its main treatment components. The results from these experiments
will inform them on how solar exposure can assist in the degradation of these drugs without further treatment. This work was presented at the 2017 Southern California Conferences for Undergraduate Research that was held on Nov. 18, 2017 at Cal Poly Pomona.
|Chemistry lab at UKZN||The UKZN project team and PEER Project Manager|
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