Abstract: Disclosed is a process and apparatus that uses multiple stages or unit processes to treat wastewater, such as distillery spent wash which may be molasses spent wash (MSW). The stages include one or more of anaerobic digestion, chemical treatment, electrocoagulation, aerobic treatment, physical separation, and RO or adsorbent based treatment. A chemical treatment for the effluent from an anaerobic digester treating MSW is described. In an electrocoagulation step, a stable cathode is used to also provide electroflotation and hardness precipitation. Aerobic biological treatment and physical separation may be provided by a membrane bioreactor.