PhD project: Treatment of source separated greywater for lower effluent requirements with MBBR and Horizontal Filters

This is Ashley Hall’s doctoral thesis. Ashley is an industrial doctoral student from Sweden Water Research through Lund University.

About the Project:

In the future we will need to achieve lower concentrations of nutrients like nitrogen and phosphorous that can cause algal blooms when they remain in effluent wastewater in high concentrations. That is why we have environmental quality norms (MKN). The goal of wastewater treatment is to meet the MKN. One solution that could help to achieve these norms is separating wastewater at the source. Separated water can be classified as black water from the toilet and greywater from showers, sinks, washing machines, and all other wastewater sources besides the toilet. Sometimes, there is even a third classification of water from the kitchen sink; food waste.

Black water contains a large portion of the contamination while greywater contains lower concentrations of contaminants than even conventional mixed wastewater. This means that lower concentrations are entering the wastewater treatment plant as greywater. These lower concentrations allow us to target treatment to specific contaminants like nutrients.

Another advantage of source separated greywater is the possibility to treat greywater on site in small treatment plants that do not need long pipe networks. With simple solutions this type of treatment plant could reduce the operating costs and help to develop new neighborhoods without overwhelming the preexisting wastewater treatment plants.

This project studies the pretreatment of greywater with a biological step that uses MBBR (Moving Bed Biofilm Reactor) followed by horizontal filters as well as a study into the effectiveness of long running horizontal filters.

Supervisor: Åsa Davidsson

Project goal

Prove that local greywater handling can achieve effluent levels that are not beyond the environmental quality norms for the recipient.

Project members from Sweden Water Research and and its owners

Partners in this project