News in brief

NIWA/University of Waikato funded PhD student Femke Rambags is advancing our understanding on the ability of woodchip and coconut filters to remove faecal bacteria and viruses from wastewater.

Land application is often the final step for treating wastewater from septic tanks. With relatively low costs and limited operation and maintenance requirements, the septic tank and land disposal treatment system is relatively inexpensive, however it is not particularly effective for nitrogen removal. As a result, large land areas are often required for wastewater disposal following septic tank treatment. Additionally, care must be taken to prevent the transmission of infectious diseases through leaching of waterborne pathogenic microorganisms, present in septic tank effluent, to surface and ground waters.

Inclusion of a secondary treatment step between the septic tank and land disposal areas offers opportunities for reducing land area required and preventing the transmission of infectious diseases, by removing nitrogen and by reducing pathogens from septic tank effluent.  Numerous studies have identified denitrifying bioreactors     (woodchip filters) as a robust alternative for improving nitrogen removal in onsite wastewater treatment systems. In addition, there are indications that these systems are also capable of removing faecal microbes.

Working with NIWA and the University of Waikato, the objective of my PhD project is to determine how well denitrifying bioreactors remove faecal bacteria and virus loads from septic tank effluent. The findings from my research will contribute to the design of robust, low-cost, cost-effective, low-energy usage, high-rate onsite wastewater treatment systems.

Introducing Femke Rambags

I graduated with a BSc in Earth Sciences from the University of Utrecht in the Netherlands. 

My interest in water management and curiosity for tackling water management related problems led me to pursue an MSc in Hydrology (University of Utrecht) and, later, an MSc in International Land and Water Management (Wageningen University, the Netherlands). I was able to further explore my interests at KWR Watercycle Research Institute (the Netherlands), where I had the chance to work on a broad range of hydrological issues as a junior researcher.

I moved to New Zealand in June of 2014 and am currently doing a PhD through the University of Waikato where, together with NIWA, I will be investigating the ability of woodchip and coconut filters to remove faecal bacteria and viruses.