Abstract: A control system for a liquid-solid contacting apparatus and method therefor is designed to greatly minimize the dilution and contamination of the product streams as well as to perform the desired separation, concentration or conversion reactions at peak efficiency.The liquid-solid contactor comprises a loop; a plurality of loop valves dividing the loop into loading, pulse and regenerating sections; feed means for supplying a feed containing sorbable material to the loading section; sorption solid substantially filling the loop; regenerating means for supplying regenerating fluid to the regenerating section; first removal means for removing the material desorbed by the regenerating fluid from the loop; second removal means for removing the processed liquid from the loop; pulse inlet means for supplying a pulse liquid to the pulse section and an outlet means for removing a portion of the pulse liquid from the loop.