Removal of pollutants from aqueous solution with magnetic biochar: a mini review

AbstractIn the last decade, there has been increasing scrutiny of using biochar to remove pollutants from the waste water. However, due to particle size of biochar and the difficulty of its separation after the adsorption process, the use of these adsorbents has always been a challenge, until magnetic biochar (MB) was proposed by researchers. The production of MB is divided into pre-pyrolysis and post- pyrolysis methods. The MB activation/modification methods included physical and chemical activation/ammonization, sulfurization, oxidation, polymerization and MB production without modification/activation was investigated. In this research, studies that produced MB as a one-step heating and post-pyrolysis method reviewed. The results showed that the capacity of different MB to remove lead, cadmium, chromium, copper, and arsenic was calculated to be 96.9, 91.2, 90.5, 97.6 and 55.42%, respectively. In these studies, the weight ratio of the magnetic fraction to biochar, temperature, and carbonization time were 1.2 (g/g), 575 °C, and 130 min, respectively. During the absorption process, the adsorption capacity of magnetic biochar increased and then reached a constant value. Therefore, the magnetic biochar has good ability to hold the adsorbed pollutants to the end of process. Also, as the initial pollutant concentration increased, the adsorption capacity unexpectedly increased and eventually reached its maximum, indicating a high affinity of the magnetic biochar with the pollutants.Keywords: Activated carbonadsorptionmagneticbiocharbiomasscarbonization AcknowledgmentsThe support of this organization is appreciated.Disclosure statementNo potential conflict of interest was reported by the author(s).Additional informationFundingThis study was funded by the University of Lorestan, Lorestan, Iran.