A review on microwave-assisted synthesis of adsorbents and its application in the removal of water pollutants

[Display omitted] •Enhanced adsorption for various water pollutants onto microwave synthesized adsorbents was reported.•Microwave synthesized adsorbents showed better porous structure relative to conventional synthesized ones.•Effect of microwave heating technique on the adsorbent physiochemical properties was discussed.•The advantages and disadvantages of using microwave heating in adsorbent preparation were summarized. The use of conventional heating techniques in adsorbents preparation involves long synthesis time, high energy consumption, high cost and material fast firing. Recently, Microwave heating technique has been used to replace or complement the conventional heating in adsorbents preparation as it provides rapid, selective, and uniform heating. Consequently, the adsorbent microscopic structure and adsorption performance are affected significantly. The current review critically investigates the effect of using microwave heating technique on Carbon based, minerals and polymeric adsorbents’ morphology, surface chemistry, and pore structure. In addition, the adsorption performance of water pollutants using microwave synthesized adsorbents, adsorption kinetics and isotherms were included. A competitive comparison in terms of adsorbent morphology, pore structure and adsorptive behavior between adsorbent prepared by microwave and convention heating technique were discussed. Finally, challenging, and promising routes are suggested for future development of microwave prepared adsorbents for water pollutants removal. On the basis of this review, using microwave technology in adsorbents preparation is promising, however, further development and investigation are substantially still required.