A system is provided for removing dissolved metals from industrial wastewater by electrocoagulation. The system includes an electrocoagulation reactor with a DC power supply having an insulation support enclosure with positive and negative electrode plates disposed thereon. The electrode plates are insulated for each other but remain in direct contact with the wastewater as it flows between the electrodes. The DC power supply induces opposite charges on alternate electrodes thereby generating an electric field between adjacent electrodes to cause the electrodes to ionize and go into solution for interaction with the contaminants in the wastewater as it flows through the reactor. The reactor is housed in a pressure vessel container so the exterior pressure on the reactor is higher than its internal pressure preventing leakage of fluids and oxygen and hydrogen gases produced in the reactor by decomposition of water. The pressure vessel allows higher operating pressures to retain higher concentrations of dissolved oxygen and hydrogen dispersed in the water for reaction with the contaminants. The electrical supply includes explosion proof connection housings for operation in hazardous environments. The system also includes a cyclone filter for separating the precipitated solid particles from the fluid and automatic control of the reactor by monitoring fluid flow, temperature, pH, and pressure.