Occurrence, fate, and potential risk of pharmaceutical pollutants in agriculture: Challenges and environmentally friendly solutions

Abstract

In recent years, pharmaceutical active compounds (PhACs) have attained global prevalence. The behavior of PhACs in agricultural soils is complex and depends on several factors, such as the nature of the compounds and their physicochemical characteristics, which affect their fate and potential threats to human health, ecosystems, and the environment. The detection of residual pharmaceutical content is possible in both agricultural soils and environmental matrices. PhACs are commonly found in agricultural soil, with concentrations varying significantly, ranging from as low as 0.048 ng g^-1 to as high as 1420.76 mg kg^-1. The distribution and persistence of PhACs in agriculture can lead to the leaching of these toxic pollutants into surface water, groundwater, and vegetables/plants, resulting in human health risks and environmental pollution. Biological degradation or bioremediation plays a critical role in environmental protection and efficiently eliminates contamination by hydrolytic and/or photochemical reactions. Membrane bioreactors (MBRs) have been investigated as the most recent approach for the treatment of emerging persistent micropollutants, including PhACs, from wastewater sources. MBR- based technologies have proven to be effective in eliminating pharmaceutical compounds, achieving removal rates of up to 100%. This remarkable outcome is primarily facilitated by the processes of biodegradation and metabolization. In addition, phytoremediation (i.e., constructed wetlands), microalgae-based technologies, and composting can be highly efficient in remediating PhACs in the environment. The exploration of key mechanisms involved in pharmaceutical degradation has revealed a range of approaches, such as phytoextraction, phytostabilization, phytoaccumulation, enhanced rhizosphere biodegradation, and phytovolatilization. The well-known advanced/tertiary removal of sustainable sorption by biochar, activated carbon, chitosan, etc. has high potential and yields excellent quality effluents. Adsorbents developed from agricultural by-products have been recognized to eliminate pharmaceutical compounds and are cost-effective and eco-friendly. However, to reduce the potentially harmful impacts of PhACs, it is necessary to focus on advanced technologies combined with tertiary processes that have low cost, high efficiency, and are energy-saving to remove these emerging pollutants for sustainable development.

Keywords: Biochar; Composting; Cost-effective; Membrane bioreactors; Microalgae; Phytoremediation.