Tomi Turner

Biography

I received my BSc in Environmental Earth Sciences from Aberystwyth University in 2016. Following this, I went on to complete my MRes in Environmental science at Aberdeen University in 2017. During these courses my main research focus was geochemistry and soil science.

In 2017 I began my PhD at Keele University under the supervision of Dr. Ian Oliver. My project focusses on the application of novel soil amendments and their related ecological impacts. This project is NERC funded and part of a CASE partnership with the 4R group.

Research and scholarship

Project:

Title: Ecological risk characterisation of novel soil amendments: assessing impacts on earthworms and soil microbial functions

Supervision: Dr Ian Oliver, Dr David Thompson

Funding: NERC and The 4R group (CASE partner)

Water treatment residuals (WTRs) are by-products of the coagulation and flocculation phase of the drinking water treatment process. They mainly comprise of Al/Fe precipitates, but also incorporate impurities that they have removed from drinking water, leading to a high variance in chemical composition.

One of the largest disposal routes of these WTRs is via landfill (57% in the UK, 40% in the U.S.A. and 21% in Japan), related disposal costs being a key driver behind the price of the drinking water treatment process. However, WTRs have many physical and chemical properties (e.g. high sorption capacity and porosity) that lend them to potential positive reuse routes. In particular, WTRs have displayed great potential as a soil conditioner (i.e. soil stabilisation, fertiliser replacement, nutrient control and contaminant immobilisation).

Land application of WTRs offers an economical win-win situation for drinking water providers and land managers. However, current environmental regulations tightly restrict WTR use because of perceived risks of metal leaching (especially Al), P immobilisation and fears of resulting impacts on soil biological and chemical processes. For example, it is still uncertain what impacts this may have on earthworm populations and diversity, soil porewater chemistry, and soil microbial function.

The aims of this study are to examine these potential effects over the short- and long-term via a series of field, semi-field mesocosm and laboratory experiments. Once this project addresses these uncertainties, it can help to develop informed policy positions and regulations that will permit the beneficial use of WTRs without risking damage to the environment.