BIOTRANSFOROMICS: Bioanalysis to Engineer Understanding in Wastewater Treatment

The wastewater treatment process (WWTP) plays a critical role in providing clean water. However, emerging and predominately unregulated, bioactive chemicals such as steroids and pharmaceutical drugs are being increasingly detected in surface waters that receive wastewater effluent. Although present at low concentrations, their inherent bioactive nature has been linked to abnormalities in aquatic organisms and there are also water reuse and human health implications. As part of the urban water cycle, the WWTP is the gatekeeper to the surface waters e.g. rivers. Pharmaceuticals enter wastewater treatment from inappropriate disposal of unused drugs to the sink/toilet or via landfill. Prescribed or illicit drug use also has the inevitable consequence of being metabolised in the human body (to parent, Phase I / II metabolites) and excreted in urine, which subsequently enters the WWTP. Coupled with naturally produced and excreted bioactive steroids, the challenge for wastewater treatment is that it was never designed to remove these bioactive chemicals and is inefficient.

Evaluating the prevalence and fate of a steroid or pharmaceutical in the WWTP is challenging as human enzymatic metabolism causes the bioactive chemical to exist in multiple forms - parent, Phase I and Phase II metabolites. Phase II metabolites predominate urine excretion and are the starting products entering the wastewater environment. They therefore act as the precursors to the biotransformations that take place during treatment and produce the Phase I and/or parent forms of the bioactive chemical. Before treatment technologies can be developed and evaluated for pharmaceutical and steroid removal in the WWTP, our understanding needs to improve on how the different bioactive chemical forms behave, and their relationships to each other. This means identifying the biotransformations between metabolites and parent forms. To achieve this requires a move from targeted analysis - we analyse for what we expect to see - to develop methods that are non-targeted and search for Phase II metabolites and their associated Phase I / parent forms.

Drawing on inspiration from metabolomics approaches used in the biosciences, the aim of this proposal is to develop a novel non-target method to identify bioactive chemical Phase II metabolites and their biotransformation products in wastewater. Knowledge of Phase II metabolite occurrence and fate in the wastewater environment is important in assessing the impact of user behaviour, process and environmental factors or bioactive chemical parent removal. This will inform on WWTP efficiency, provide data for optimising models that predict pharmaceuticals and steroids, and evaluate environmental risk.

The proposed research will accelerate understanding by providing a method to identify Phase II metabolites and their biotransformation products without bias. Application of this method will identify pharmaceuticals and steroids of concern in UK wastewater and importantly account for the relationships between the different metabolite and parent forms that exist in the wastewater environment.

Pharmaceutical manufacture is one of the UK's leading industries, with medicines accounting for 10% of the NHS budget to support the health and well-being of the population. Growing awareness of pharmaceuticals in wastewaters, surface waters and even drinking water has led to closer scrutiny and increasing regulation of pharmaceuticals and waste. Although present at low concentrations, their inherent bioactive nature has been linked to abnormalities in aquatic organisms and there are also water reuse and human health implications. The wastewater treatment process (WWTP) is a gatekeeper to maintaining the urban water cycle and providing clean water for all. The societal impact of this research is clear, to support and enhance human and environment health. Impact also extends to the pharmaceutical industry who are committed to ensuring drug manufacture, use and disposal does not adversely affect human health or the environment (e.g. Pfizer's PIE - Pharmaceuticals in the Environment).

This research is highly relevant to Water Companies in evaluating WWTP effectiveness for removing bioactive pharmaceutical drugs and steroids. In particular the UK Water Industry Research organisation who developed the Chemical Investigation Programme (CIP) in collaboration with the Environment Agency to assess the scope of requirements involved in upholding the recent European Directives - the Water Framework Directive (WFD) and the new Priority Substances Daughter Directive - put in place to regulate Environmental Quality Standards.

It will align and add value to the UK Water Industry £140M CIP 2 that begins in 2015. For this, Water Companies are required to deliver an ambitious programme of sampling and analysis until 2020 to understand the impact of priority hazardous substances, specific pollutants, emerging substances and pharmaceuticals to and from wastewater treatment works on the environment. In addition the UK regulators are required to set their own standards for further potential pollutants and are aware that to respond to these obligations requires greater understanding of the effectiveness of WWTPs for removing BACs.

This proposal also impacts on the increasingly stringent EU requirements in water quality and pollution control e.g. the 2013 Watch List under the WFD that requires EU-wide monitoring of one steroid and two pharmaceuticals to support the prioritisation process in future reviews of the priority substances list. Impact also goes beyond the EU including the Global Water Research Coalition and US Environmental Protection Agency.