A method for washing an adsorptive medium within a water treatment system, comprising the steps of: a. providing a first and a second vessel, wherein said first vessel contains the adsorptive medium to be regenerated, wherein the adsorptive medium comprises a porous filter medium which is a granular porous filter medium that preferably comprises granular or powdered activated carbon, wherein the porous filter medium comprises a filter element comprised of at least one filter bed of adsorptive medium with a filtration flow there through, and forms a first filter bed within at least the lower portion of the first vessel, the filter bed comprising an upper surface and a lower surface and configured for filtration of contaminated water through the filter bed and periodic washing thereof, which first filter bed is a fixed-bed filter, and wherein the second vessel is in fluid communication with the first vessel; and b. performing a washing stage with a wash fluid by cycling a flow of the wash fluid between the first and second vessel in a first and second flow direction to produce a back-and-forth flow of the wash fluid through the adsorptive medium, wherein the back-and-forth flow of the wash fluid between the first and second vessel is performed for a sufficient number of cycles and a time period sufficient to at least partially regenerate the adsorptive medium, thereby producing a processed wash fluid; and c. stopping the back-and-forth flow of the processed wash fluid between the first and second vessel; and d. performing a step selected from the group comprising draining the processed wash fluid from the first vessel, draining the processed wash fluid from the second vessel, flushing the first vessel, flushing the second vessel, discharging the processed wash fluid to waste, neutralizing the processed wash fluid, treating the processed wash fluid to generate at least one additional wash fluid for reuse, rinsing the adsorptive medium, returning to filtration flow, and combinations thereof. a. providing a first and a second vessel, wherein said first vessel contains the adsorptive medium to be regenerated, wherein the adsorptive medium comprises a porous filter medium which is a granular porous filter medium that preferably comprises granular or powdered activated carbon, wherein the porous filter medium comprises a filter element comprised of at least one filter bed of adsorptive medium with a filtration flow there through, and forms a first filter bed within at least the lower portion of the first vessel, the filter bed comprising an upper surface and a lower surface and configured for filtration of contaminated water through the filter bed and periodic washing thereof, which first filter bed is a fixed-bed filter, and wherein the second vessel is in fluid communication with the first vessel; and wherein said first vessel contains the adsorptive medium to be regenerated, wherein the adsorptive medium comprises a porous filter medium which is a granular porous filter medium that preferably comprises granular or powdered activated carbon, wherein the porous filter medium comprises a filter element comprised of at least one filter bed of adsorptive medium with a filtration flow there through, and forms a first filter bed within at least the lower portion of the first vessel, the filter bed comprising an upper surface and a lower surface and configured for filtration of contaminated water through the filter bed and periodic washing thereof, which first filter bed is a fixed-bed filter, and wherein the second vessel is in fluid communication with the first vessel; and b. performing a washing stage with a wash fluid by cycling a flow of the wash fluid between the first and second vessel in a first and second flow direction to produce a back-and-forth flow of the wash fluid through the adsorptive medium, wherein the back-and-forth flow of the wash fluid between the first and second vessel is performed for a sufficient number of cycles and a time period sufficient to at least partially regenerate the adsorptive medium, thereby producing a processed wash fluid; and c. stopping the back-and-forth flow of the processed wash fluid between the first and second vessel; and d. performing a step selected from the group comprising draining the processed wash fluid from the first vessel, draining the processed wash fluid from the second vessel, flushing the first vessel, flushing the second vessel, discharging the processed wash fluid to waste, neutralizing the processed wash fluid, treating the processed wash fluid to generate at least one additional wash fluid for reuse, rinsing the adsorptive medium, returning to filtration flow, and combinations thereof.