WRRF webcast on reuse disinfection research results

The WateReuse Research Foundation is using a webcast on 12 July 2012 to highlight the results of a project investigating the occurrence of intestinal pathogens in recycled water and the effectiveness of disinfection.

The webcast, Investigating the Occurrence of Infectious Cryptosporidium Oocysts in Recycled Water and Evaluating the Effectiveness of Various Disinfection Techniques (WRF-06-003), will explore impacts of chlorine‑based disinfection on biodegradable carbon-based compounds. It will also assess the feasibility of disinfectant optimization for membrane bioreactors, which typically produce higher quality wastewater effluents than conventional treatment.

Cryptosporidium and Giardia are intestinal pathogens of significant public health concern. To understand the potential human health impact of these organisms during water reclamation, their occurrence, infectivity and species characterization needs to be understood.

Data from geographically dispersed wastewater utilities employing conventional secondary clarification or advanced processes (ie, sand filtration, membrane bioreactors and cloth filtration) were used to estimate risk of human disease. Effective risk-management needs to extend beyond physical removal processes and into optimized disinfection strategies.

Disinfectant optimization is a double-edged sword: too little leads to insufficient kill of pathogens; too much causes undesirable health, operational or financial impacts (disinfectant byproduct formation, generation of biodegradable carbon fractions). Disinfectant optimization will not only help manage chemical costs but may reduce biodegradable carbon fractions, which can contribute to bacterial growth in reclaimed water distribution systems.