NOVELTY - A biochar water treatment system comprises fluid flow pathway (2) containing wastewater inlet (4), biochar inlet, and reactor (8), filter (6), treated water outlet, and reject stream outlet.    USE - A biochar water treatment system.    ADVANTAGE - Biochar water treatment system has high efficiency and low cost, enhances water treatment and nutrient reuse, and increases reactive adsorptive efficiency of carbonaceous substrate.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for:    (1) biochar water treatment which involves adding biochar (10) to wastewater stream containing greater than or equal to 1 contaminant and separating biochar and greater than or equal to 1 contaminant from wastewater stream to produce treated water stream (18) and reject stream (20); and    (2) biochar water treatment which involves pyrolyzing biomass to produce biochar and heat, steam, and/or syngas, generating electrical energy using heat, steam, and/or syngas, partially powering wastewater treatment system with electrical energy, introducing wastewater stream containing greater than or equal to 1 contaminant to biochar treatment system, adding biochar, adding iron salt, adding ozone, mixing in plug flow reactor, filtering in moving bed reactive sand filter to product treated water stream and reject stream, removing solids from reject stream to produce recycled water stream and solid product, and formulating solid product for use in agricultural, residential, commercial, or municipal land or horticultural soil containers in which biochar water treatment system comprises fluid flow pathway containing wastewater inlet, biochar inlet, metal salt inlet, ozone inlet, and reactor, filter, treated water outlet, reject stream outlet, and solid separator.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic diagram of biochar water treatment system.    Fluid flow pathway (2)    Wastewater inlet (4)    Filter (6)    Reactor (8)    Biochar (10)    Water stream (18)    Reject stream (20)