Research Interests
and Approach

My background is in sanitary engineering and over the years I have developed a keen interest in food and farming systems. My current research interest connects these two fields and asks how recycling of nutrients and organic matter contained in human excreta might best support farming systems that seek to regenerate soil and maintain long-term soil health. I am also interested in exploring what assessment tools and frameworks are appropriate when it comes to finding answers to this question.

Research methods I use include quantitative methods such as substance flow analysis as well as qualitative methods such as interviews and focus groups.

Current Research

Managing human excreta for soil, food and nutrient security

Past Research

Blending Elements of Risk Assessment and Life Cycle Assessment

Risk assessment (RA) and life cycle assessment (LCA) are two analytical tools commonly used to support decision making in sewage sludge management and other contexts. RA and LCA were initially developed and used by largely separate groups of specialists, but there is scope for blending elements of the two tools. This research reviewed environmental assessment case studies blending elements of RA and LCA and identified a range of opportunities and pitfalls. The work also featured an attempt to build a Life Cycle Impact Assessment (LCIA) model for human toxicity inspired by quantitative chemical risk assessment (QCRA).

Including Pathogen Risk in Life Cycle Assessment

Human health risks associated with the exposure to pathogens in urban water infrastructure are of common concern but had not been accounted for in life cycle assessment (LCA). This research explored the possibility to include pathogen risk in LCA. The work drew heavily from quantitative microbial risk assessment (QMRA) and helped identifying opportunities and unresolved issues when attempting to include pathogen risk in LCA.

Material Flows at the Level of Individual Households

The study of household metabolism - stocks and flows of energy, matter, and information at the household scale - seeks to support pro-environmental behaviour. This research explored ways to quantify goods purchases and waste generation at the level of individual households. This research also contributed to mapping contributions and perspectives of a various research traditions that have an interface with household metabolism, highlighting a number of controversial issues.

Flows and Management of Phosphorus in Urban Areas

Phosphorus (P) is a plant nutrient of paramount importance for food security. Many current agricultural and waste management practices lead to a dispersion of phosphorus to different sinks. There is a growing awareness of the need for better P management and more circular P flows. This research mapped flows and sinks of P in Gothenburg, Sweden, for the urban water infrastructure in place in the year 2009, and for a range of possible future scenarios.

Source Separation in the Existing Urban Water Infrastructure

In conventional sewer networks water is used to convey human excreta to sewage treatment plants (STPs). Municipal sewer systems commonly also serve industry and hospitals, sometimes even stormwater is drained through the same pipes. It has long been proposed that separating streams at the source would provide greater opportunities for resource recovery by finding ways to minimise dilution and contamination of human excreta. This researched explored and mapped the potential for separate collection and transport of black water in the existing building infrastructure.