Research On The Use Of Mining And Metallurgy Wastes As Substrate In Constructed Wetland For Treating Domestic Sewage

With the dramatic growth of population and the rapid development of the society andeconomic, the emissions of domestic sewage increase sharply, which caused greater burden tothe water environment. The traditional sewage treatment plants are large cost, complexmanagement and low processing efficiency. As a new ecological technology with less investment,simple structure and high efficiency, constructed wetlands will be widely used in our country.In China, a great mount of mining and metallurgy waste such as steal scoria, fly ash, tailingshave caused a secondary pollutions to the environment. What’s more, the utilization rate of thesewastes is low. In this paper, steal scoria, fly ash, two Fe mine tailings, iron shaving were used assubstrate in constructed wetlands to test their adsorption capability to domestic wastewater. Thenthe wastes with better adsorption ability were chosen as the substrate of simulate compoundvertical-flow constructed wetlands to treat sewage in laboratory.The conclusions were come up with as follows, the adsorption of these substrates for TPwas obvious in24h and the removal efficiency of fly ash and steel scoria was up to90%in10min. In the meanwhile, it was found that the adsorption of these substrates on TN and COD wasnot ideal. What’s more, the removal efficiency of contaminants increased with the dosage ofsubstrates. In the experiments of simulation column using metallurgical tailings, the columnwhich using Fe tailing had the best removal ability, the column with combination of Fe minetailing and steal scoria reached stable faster. Using Fe mine tailing and steal scoria as substrate tosimulate compound vertical-flow constructed wetlands, the removal effect on sewage pollutantwere ideal. The removal efficiency of TP, TN, COD was respectively95%,70%and95%.The results showed that the Fe tailing, steal scoria and other mining and metallurgy wastescould be feasible used as substrate in constructed wetlands to treat domestic wastewater. Thestudy provided the basis for the selection of substrate in the future.