WASTEWATER TREATMENT APPARATUS

摘要

PROBLEM TO BE SOLVED: To provide a wastewater treatment apparatus capable of stepwise controlling the dwell time of wastewater in contact with a contact material corresponding to the concentration of a dissolved substance in untreated wastewater to allow the operation of the wastewater treatment apparatus to rapidly follow a change in the concentration of the dissolved substance in untreated wastewater and especially suitable for the selenium removing treatment of selenium-containing wastewater. SOLUTION: The wastewater treatment apparatus is constituted so as to bring wastewater containing the dissolved substance such as dissolved selenium or the like into contact with the contact material such as a contact reducing material or the like comprising a ferreous metal for precipitating the dissolved substance from wastewater to remove the dissolved substance from wastewater. A plurality of treatment spaces are formed to the apparatus main body and a wastewater flow channel is formed so as to move wastewater treated in the upstream treatment space to the downstream treatment space. Contact zones for bringing wastewater into contact with the contact material are provided to the respective treatment spaces and introducing ports for introducing the untreated wastewater into the treatment spaces are provided. The introducing port for introducing wastewater into the apparatus main body is selected corresponding to the concentration of the dissolved substance in the untreated wastewater and the wastewater flow routes in the apparatus main body are changed over so that the concentration of the dissolved substance in wastewater after treatment becomes a target set value range.