Wastewater reuse in agriculture: Prospects and challenges

Abstract

Sustainable water recycling is an urgent concern, considering water scarcity due to climate change, and increase water consumption through human activities. In 2015, United Nations Sustainable Development Goal 6 (UN SDG6) highlighted the necessity to reuse treated wastewater to guarantee water availability for everyone. Currently, wastewater irrigation (WWI) of crops and agricultural land appears essential. The present review shows how the quality of treated wastewater impacts soil microbial activities, and discusses challenges and benefits associated with wastewater reuse in agriculture and aquaculture irrigation. Combining advanced and conventional wastewater treatment processes is specifically deliberated, considering the harmful human health impacts resulting from WWI using contaminated water (salts, organic pollutants, toxic metals, and microbial pathogens i.e. viruses and bacteria). Our literature survey reveals that, in addition to increased levels of pathogen and microbial threats to human wellbeing, poorly-treated wastewater results in plant and soil contamination with toxic organic/inorganic chemicals, and microbial pathogens. The impact of long-term emerging pollutants such as plastic nanoparticles for example should be established in further studies, with the development of standardized analytical technique for such new chemicals. Similarly, the reliable, long-term and extensive judgment on heavy metals threat to humanity's health should be explored in future investigations.