Climate adaptation and resilience of biofiltration as a low-cost technological solution for water treatment – A critical review

Abstract

The water supply and sanitation sector has become vulnerable due to extreme weather events such as flooding, wildfires, and droughts. Following wildfires, the erosion of ashes and unburnt carbon into surface water bodies results in higher turbidity and total suspended solids in surface water, along with elevated concentrations of dissolved organic matter. This deterioration in water quality increases the difficulty of treating these waters for human consumption, highlighting the urgent need for adaptive water treatment methods. Amid these challenges, biofiltration has emerged as a sustainable, low-cost techno-ecological solution, recognized for its ability to enhance water quality while remaining environmentally friendly. The effectiveness of biofiltration stems from its utilization of microbial communities and natural processes, enabling it to adapt and recover from disruptions. Despite the threats posed by climate change, biofiltration systems have shown strong potential for resilience, although this resilience depends on a thorough understanding of the challenges brought on by climate change. This paper reviews the impacts of extreme weather events on water quality and the operations of water treatment plants. It highlights several conventional water treatment methods and discusses their insufficiencies in treating emerging contaminants. The mechanisms through which biofiltration removes contaminants as well as the key parameters that influence biofiltration such as biofilter media, types of microorganisms, temperature, pH, nutrients supply, etc and the dominant microbes present in biofilters were reviewed. The adaptation and resilience of biofiltration systems to challenges posed by climate change in water treatment was extensively discussed. The limitations and opportunities related to the adaptation and resilience of biofiltration were discussed, emphasizing the need for more proactive measures to optimize biofiltration systems.