Assessing the removal of micropollutants in the hyporheic zones of in treated wastewater fed streams

Assessing the removal of micropollutants in the hyporheic zones of in treated wastewater fed streams

Contamination of water resources threatens drinking water security and ecosystem health globally. Emerging micro pollutants derived from pharmaceuticals, pesticides, cosmetic products and micro plastics (collectively referred to as trace organic compounds, TrOCs) are present in wastewaters.

Details

Until recently these compounds could not be detected, and to a large degree remain untreated in wastewater treatment plants. TrOCs therefore remain present in treated wastewater discharged into natural environments, mainly streams, which may subsequently flow into lakes, estuaries and oceans. Recent studies have found that TrOCs accumulate in food webs , and may result in animals being exposed to doses of pharmaceuticals equivalent to humans. Exposure to these elevated levels of chemicals may have significant impacts on the functioning of ecosystems. It is therefore vital to understand the fate  of TrOCs in the environment.

The hyporheic zone, which comprises of the sediments in stream beds, provides an environment where both surface water and groundwater mix. The conditions present result in steep redox gradients, high microbial turnover rates and increased residence times resulting in favourable conditions for reactions that improve water quality to take place. The conditions in hyporheic zones have been shown to be important in removing nutrients and pollutants, but the benefits of hyporheic zones hasn’t been tested with micro pollutants and investigating this poses a challenge. Obtaining high quality spatial and temporal field data is difficult, making the characterisation of the physical and chemical processes in the hyporheic zone an ongoing challenge. This limits the ability to predict the fate  of TrOCs on large scales, hampering our understanding of the long term ecological impacts of treated wastewater discharge.

This project aims to develop both novel field and interpretive methods producing tools to predict the fate  of TrOCs in the environment. The potential for TrOCs to impact on ecosystems is of great concern. Understanding the processes that inhibit their proliferation in stream environments is therefore essential. The outcomes of the project will assist in inferring sustainable urban water management measures.

University:      University of Western Australia

Supervisor:     Dr Jim McCallum

Student:          Anja Hoehne

Project outcomes:

  • Developed procedure for assessment of contaminant fate in wastewater
  • Mathematical tools to describe TrOC fate in urban water environments
  • An understanding of the longterm and large scale effects of TrOCs in wastewater discharge
  • Assess the potential for enhanced hyporheic exchange to increase TrOC removal

Industry benefits:

An increase in the prevalence of micro pollutants in wastewater is a potential risk for both the environment and safe drinking water supplies. Understanding how these contaminants move through ecosystems is vital in reducing this risk. This project will produce a clear methodology for assessing the fate of TrOCs in the natural environment. Having sustainable urban water management strategies ultimately means a higher quality of water within the water cycle, which has both environmental benefits, but also reduces treatment costs for future drinking water.

By demonstrating the role of the HZ in the removal of pollutants, WWTP can use this knowledge to enhance hyporheic exchange in treated wastewater effected streams. This may provide an alternative to expensive treatment processes like Ozone whilst maintaining a high quality of water in the environment. Understanding and enhancing the removal of pollutants in natural waters will also act to enhance the natural environment, helping to meet regulatory requirements and maintain high environmental standards.

Please contact Research Capability Manager Carolyn bellamy for further project and student information, or refer to the sponsorship page for 'The Process' document.

WaterRA Contact

Carolyn Bellamy | Research Capability Manager 

 

Amount being sought

$39,000 over three years

Due Date

30th Jun, 2020