Sulphate removal technologies for the treatment of mine-impacted water

Mine-impacted water, including acid mine drainage (AMD), is a global problem. While precipitation of dissolved metals and neutralization of acidity from mine-impacted water is accomplished relatively easily with lime addition, removal of sulphate to permissible discharge limits is challenging. This paper presents a high-level comparison of four sulphate removal technologies, namely reverse osmosis, ettringite precipitation, barium carbonate addition, and biological sulphate reduction. Primarily operating costs, based on reagent and utility consumptions, are compared. Each process is shown to be subject to a unique set of constraints which might favour one over another for a specific combination of location and AMD composition. Access to and cost of reagents would be a key cost component to any of the processes studied. The total cost calculated for each process also depends on the type of effluents that are allowed to be discharged.

Removal of iron and sulphate during acid mine drainage treatment using laboratory successive alkalinity producing system and its behavioural relationship

Acid Mine Drainage (AMD) is one of the persistent water pollution problems in many coal mines of U.S.A. and Canada. Only few mines in India face this problem. The treatment of acid mine water has become a statutory requirement in almost all mines of the world. Metal removal and alkalinity generation is essential feature of any AMD treatment system but sulphate removal from acid mine drainage is still given the secondary importance. In the present study, four AMDs were treated in laboratory Successive Alkalinity Producing System (SAPS) for five different hydraulic retention times (HRT). The total iron removal and corresponding sulphate removal along with net alkalinity generation were studied during AMD treatment process by SAPS. A complete removal of total iron and sulphate removal of over 59% have been achieved. The study revealed that the total iron removal and sulphate removal increases with increase in HRT and its removal exhibited linear relationship. A substantial increase in alkalinity was also found after SAPS treatment. The findings of the study can be utilized in design of SAPS for removal of iron and sulphate during treatment of AMD in mining areas.

Lampiran 5D paper Sulphate removal from wastewater in constructed wetland ecotechnology using pumice amended in the sand media

Sulphate is a part of sulphur compounds which potentially inhibit plant growth and microbial activities in receiving surface water. Thus, it is important to remove concentration of sulphate from wastewater to acceptable concentration before the water is released into aquatic system. Constructed wetlands (CWs) are good option of wastewater treatments due to their lowcost and eco technology. This research aimed to investigate the removal of sulphate from domestic wastewater using sand media amendment with pumice in CWs. In this experiment, six variations of CWs consisting sand and pumice planted with lemongrass (Cymbopogon citratus) were established. Domestic wastewater was loaded into CWs with loading rate 2 L/day. Sulphate concentrations were determined in inflows and outflows. The results showed that all treatment significantly remove sulphate concentrations from the inflow. The highest removal efficiency was in the media with 100% of pumice

Chemical Precipitation method for Sulphate Removal from Treated Wastewater of Al-Doura Refinery

Wastewater treatment by Wastewater Treatment Plant, named (INGECO) in Doura refinery suffers from the elevated level of sulphate ion concentrations compared to the recommended EPA [14] specified (250 mg/L). The annual rate, maximum and peak sulphate concentrations that found to be 360; 425 and 550 mg/L respectively. In this study samples prepared from industrial wastewater and the average, maximum and peak sulphate concentrations to be used in chemical precipitation process by using BaCl2 or Al(OH)3. Results obtained from BaCl2 treatment refer to the optimum (dosage, mixing time and mixing speed) to be used in sulphate removal for reuse purpose were (1.5 g/L, 1.2 hr and 80 rpm), (2.25 g/L, 1.5 hr and 90 rpm) and (3.0 g/L, 2 hr and 90 rpm) for each of average, maximum and peak concentrations respectively. Whereas for disposal purpose, were (0.36 g/L, 15 min and 100 rpm), (1.1 g/L, 15 min and 70 rpm), (1.72 g/L, 15 min and 90 rpm) respectively. This process was achieving of highly sulphate removal, but expensive. Whereas the results obtained by using Al(OH)3 indicated unsuitability for treated refinery wastewater treatment of low sulphate concentrations and neutral pH.