Removal of pharmaceuticals and personal care products from water and wastewater through biological processes: an overview

The consumption of pharmaceuticals and personal care products (PPCPs) is increasing as the global population grows. These types of emerging pollutants consist of various groups of drugs used in veterinary, agricultural practices, cosmetics, and human health, such as analgesics, hormones, antibiotics, etc. Because of the incapability of physical treatment processes (e.g., reverse osmosis, nanofiltration) and biological processes (e.g., activated sludge) to degrade PPCPs, they are discharged into lakes, rivers, and groundwater. The mechanism of biological removal of emerging pollutants from wastewater lies predominantly in their biodegradation by microorganisms such as algal, fungi, and bacteria into small molecules or water and carbon dioxide. Biological treatment technologies include a variety of conventional and unconventional methods such as activated sludge, membrane bioreactors, aerobic, anaerobic, microalgae and fungal bioreactors, trickling filters, denitrification, nitrification, and biosorption and constructed wetlands. The increasing use of intractable drugs and cosmetics together with the inability of activated sludge systems used as a biological treatment in most wastewater treatment plants to remove PPCPs make the treated effluents contain substantial concentrations of PPCPs. Therefore, comprehensive research is needed on the removal of the above-mentioned pollutants by biological processes in future studies.