A semiconductor laser capable of emitting in any one of standard communication wavelengths is of great practical value. Pipes from respective actuators are connected to the respective pipe joints in advance. The terminal equipment includes: a handover command receiving unit, a sending unit, and a random response receiving unit. 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.