MEDIA OF CONSTRUCTED WETLAND FOR THE TREATMENT OF MUNICIPAL WASTEWATER AND PREPARATION METHODS THEREOF

摘要

A media for a constructed wetland comprising oldhamite reduced from gypsum or/and waste gypsum is provided to attach microorganisms to the media effectively such that the microorganisms grow on the media by applying the media to various places including facilities for purifying municipal wastewater and contaminated river water, post-treatment facilities of nonpoint source pollutants and sewage/wastewater, etc., and a preparation method of the media is provided. A media for a constructed wetland comprises 5 to 90 wt.% of oldhamite and 10 to 95 wt.% of a component mixture based on the total weight of the media for the constructed wetland. The component mixture is silica, alumina, calcium oxide, sodium oxide, iron oxide, potassium oxide, magnesium oxide, calcium carbonate, activated carbon, or mixtures thereof. A preparation method of a media for a constructed wetland comprises: a mixing step of mixing 100 wt.% of gypsum or/and waste gypsum with 15 to 80 wt.% of activated carbon, 20 to 50 wt.% of oyster shell, 30 to 200 wt.% of bentonite, 80 to 200 wt.% of a reinforcing agent, 10 to 200 wt.% of a binder, and 150 to 400 wt.% of water; a molding step of molding the mixture into a desired shape; a drying step of drying the molded mixture at a temperature of 20 to 150 deg.C; a firing step of injecting the dried mixture into a heating furnace and firing the dried mixture at a temperature of 800 to 900 deg.C in a reductive atmosphere for 0.1 to 4 hours; and cooling the fired material to room temperature. The preparation method further comprises an adaptation step of adapting the media for the constructed wetland in an alkaline solution or a sulfate-containing alkaline solution with a pH of 8 to 13 for 0.1 to 7 days.