Bentonite/carbon composite development for the treatment of agroindustrial effluents

Abstract

The diphenylamine antiscale (n-phenylbencenamine) is an agrochemical widely used in the post-harvest treatment of stone fruits in the Upper Rio Negro Valley, Argentina and the discharge exceeds the allowable limits in the water courses. Removal was evaluated using a composite whose matrix allows bentonite to maintain its adsorbent capacity without thereby reducing the porosity of the bed. This was formed in self-supporting, porous and adsorbent monoliths, emulating the operation in fixed bed columns with the advantage over a conventional fixed bed filled column of reducing the packing variables being the pressure drop, bed height, porosity, and others. If we compare with batch operation what is proposed requires less amount of adsorbent material and reduces the generation of liquid waste. Also, removal was evaluated and compared using a bentonite composite with carbon added. The composites had a maximum adsorption capacity of 80% and desorption of 15% in 1 h.