Bioregeneration of saturated natural mordenite to reduce iron and manganese in groundwater

Abstract

Significant improvement of technologies was developed to remove iron and manganese contamination from ground water. One of the technologies is the use of adsorbents but, recycling of used adsorbents is little to be done. Only a few researchers reported studies that highlighted on recovery of adsorbent through biological processes. In this study, bio-regeneration chosen as a technical approach to reduce the rate of waste generation from the saturated mordenite (adsorbent). The principle of bio-regeneration adopted the mechanism of desorption after the use of adsorbents by empowering single culture of microorganism. To determine its capacity, activated minerals mordenite were used to treat water containing 2.29 ppm of Iron and 2.47 ppm of manganese for the first stage (Pre bio-regeneration). This artificial iron and manganese contaminated solution was used as a representation of ground water in Bandung area. The reactor used have continuous stream with up-flow direction. Iron and manganese removal efficiency respectively in the 1st stage of adsorption (before bio-regeneration process) reaches 95% and 97%. After the 72 hour submergence process by cultivated Thiobacillus ferooxidan, ability of the adsorbent still fulfil the drinking water quality standard in Minister of Health Regulation No. 492 of 2010. The removal efficiency reached 85% for iron but not suitable for manganese which only reached 30% of removal. This bio-regeneration can be applied as much as 2 times rounds.