A review on effective removal of pharmaceuticals from aquatic systems: Advanced techniques and scope for future research

Abstract

Advances in medical research have led to a significant increase in the consumption and usage of pharmaceutical products. The chemical constituents of these products, including chemicals like tetracyclines, salicylic acids, sulphonamides and quinolones, are collectively known as   Pharmaceutically Active Compounds (PhACs). Originating from domestic effluents, this micro-pollutant fails to degrade when processed by conventional methods. Accumulation of these treatment-resistant pharmaceutical compounds in soil and water bodies is dangerous, as they act as poisons to the natural environment. The aim of this study is to consolidate the investigated physical, chemical and biological methods for removal of PhACs.

Microorganisms can facilitate the decomposition of PhACs and are often used in conjunction with membrane technology to effect what is known as Biological treatment. With minimal chemical addition and low energy requirements, it is the most cost-effective treatment plan. Emerging Biological treatment processes include: Membrane Biofilm Reactor (MBFR), Nanofiltration, Reverse Osmosis and Integrated Fixed-film Activated Sludge (IFAS) Systems. Addition of chemicals can either break large molecules into smaller simpler compounds, or improve removal efficacies by forming flocs or a heavier particle mass. Physical methods generally do not succeed in complete remediation. Chemical processes include Fenton Oxidation, Photocatalysis and ozonation processes. However, there is a need to control the potential formation of by-products as well as optimization of parameters to become competitive in economic terms. Thus, advanced techniques like Microbial degradation and Phytoremediation were explored.