Performance Evaluation of Waste Materials for the Treatment of Acid Mine Drainage to Remove Heavy Metals and Sulfate

Acid Mine Drainage (AMD) is the most severe environmental problem facing the mining sector in the current scenario because of low pH and high pollutants concentration. AMD contains a high amount of sulphate viz. pyrite, FeS2, and to a lesser extent pyrrhotite and heavy metal ions, contaminate both surface water and groundwater. To treat AMD, extensive research projects have been initiated by governments, the mining industry, universities, and research establishments. The environmental impact of AMD can be minimized at these basic levels; prevention should be taken to control the infiltration of groundwater to the pollution site and control the acid-generating process. There are some conventional active methods to treat AMD, such as compost reactor and packed bed iron-oxidation bioreactors; however, these methods have associated with costly material and high maintenance cost, which increases the cost of the entire treatment. In an alternative, the use of low-cost materials such as fly ash, metallurgical slag, zero-valent iron (ZVI), cement kiln dust (CKD), and organic waste such as peat humic agent (PHA), rice husk, and eggshell can be a valuable measure for economic viability to treat the metal-rich wastewater

Effect of superficial gas velocity and ratio of bed volume to reactor volume of inverse fluidized bed biofilm reactor on the removal of ammonia-nitrogen from wastewater

709-716Hydrodynamic parameters of an inverse fluidized bed biofilm reactor (IFBBR) have been studied using spherical polypropylene (PP) particles having average diameter and density of 5.63 mm and 920 kg/m3 respectively. Gas-phase holdup (g) was analyzed for various ratios of settled bed volume to reactor volume (Vb/Vr) and superficial gas velocities (Ug) with a liquid recirculation velocity (Ul) of 0.0021 m/s. The g values were found to increase with Vb/Vr ratios up to a certain limit and then decrease with further increase of Vb/Vr ratios. The effect of Ug, Vb/Vr ratios, and initial concentration of ammonia-nitrogen (NH4 +-N) on the removal of NH4 +-N from synthetic wastewater were studied. The optimal values of Vb/Vr ratio and Ug were found to be 0.380 and 0.0085 m/s respectively for all initial NH4 +-N concentrations. Complete removal of NH4 +-N was achieved in 8 to 44 hours for different initial NH4 +-N concentrations. It was also observed that with the increase in initial NH4 +-N concentrations, the nitrification decreases

Effect of superficial gas velocity and ratio of bed volume to reactor volume of inverse fluidized bed biofilm reactor on the removal of ammonia-nitrogen from wastewater

Hydrodynamic parameters of an inverse fluidized bed biofilm reactor (IFBBR) have been studied using spherical polypropylene (PP) particles having average diameter and density of 5.63 mm and 920 kg/m3 respectively. Gas-phase holdup (g) was analyzed for various ratios of settled bed volume to reactor volume (Vb/Vr) and superficial gas velocities (Ug) with a liquid recirculation velocity (Ul) of 0.0021 m/s. The g values were found to increase with Vb/Vr ratios up to a certain limit and then decrease with further increase of Vb/Vr ratios. The effect of Ug, Vb/Vr ratios, and initial concentration of ammonia-nitrogen (NH4 +-N) on the removal of NH4 +-N from synthetic wastewater were studied. The optimal values of Vb/Vr ratio and Ug were found to be 0.380 and 0.0085 m/s respectively for all initial NH4 +-N concentrations. Complete removal of NH4 +-N was achieved in 8 to 44 hours for different initial NH4 +-N concentrations. It was also observed that with the increase in initial NH4 +-N concentrations, the nitrification decreases