2021 Volume 9 Issue 5 Pages 226-233
Groundwater has been used as the main source of water supply in Hanoi City for more than a century. At present, 623,500 cubic meter of groundwater have been providing per day for urban districts. In recent years, groundwater pollution due to arsenic (As), iron (Fe), ammonia (NH3), and organic matters (OM) has been reported. This paper presents a review of As contamination in groundwater in Hanoi City and investigates the adsorption capacity by autoclaved aerated concrete (AAC) as a possible adsorbent for treating As contaminated water. Results showed that a high concentration of As which was up to above 800 μg/L was found in groundwater from the Southern region of Hanoi City and was associated with high concentrations of Fe, NH3, and OM. Based on the data of As and other water quality parameters, it was suggested that the degradation of OM and ferric (Fe(III)) oxyhydroxides played a role in the mobilization of As in groundwater under reductive condition. Batch and column filtration experiments using crushed grains of AAC were carried out to evaluate the treatment performance of heavy metals including As in contaminated groundwater. Especially, the column filtration experiments gave a high efficiency of metal removal (~ 100 %), implying that AAC could be a sustainable and low-cost media to treat heavy metals in wastewater.
