Thiol functionalized clay biochar composite adsorbent and its use

Abstract

The invention describes a thiol functionalized clay biochar composite adsorbent, which can be prepared by mixing bentonite-type clay rock containing montmorillonite and biochar in a weight ratio of 20:80 to 80:20, preferably 1:1, the mixture is then homogenized in a mill, preferably with high grinding efficiency to form a finely dispersed clay biochar composite; the composite is dispersed in 10 to 30 times by weight of a mixture of solvents containing deionized water and alcohol with a concentration of at least 60% vol. of alcohol with intensive stirring until a suspension is formed; subsequently, an organosilane agent with a thiol –SH functional group is added dropwise with constant stirring in an amount of 0.1 to 55% by weight based on the clay biochar composite; The pH is then adjusted to be alkaline above 7.5 using hydroxide to promote hydrolysis and condensation of silane groups and their chemical binding to the clay biochar composite, and the mixture is stirred until the reaction is complete, then the product is filtered off and washed with alcohol and deionized water, dried at a maximum of 90 °C or lyophilized at -80 to +50 °C.