Simultaneous Removal of Iron and Hexavalent Chromium Via Slow Sand Filter Inoculated With Thiobacillus ferrooxidans and Waste management

Abstract

Many places have common physical, biological, and chemical hazards and heavy metals contamination in drinking water is very important to study especially near industrial areas and mining sources. Application of microbes along with other physicochemical techniques can prove to be the suitable remediation technology for the removal of metals from water. This study aimed to remove iron and hexavalent chromium from water using slow sand filters inoculated with iron-oxidizing bacteria Acidothiobacillus ferrooxidans. An experiment was performed for 37 days under controlled conditions, a water sample was prepared synthetically and another sample was collected from water filtration plant from Abbottabad city in KP Province- Pakistan and influents and effluents were tested for different parameters like pH, turbidity, hardness, total plate count, total dissolved solids, electrical conductivity and analysis of iron and hexavalent chromium in water. Acidothiobacillus ferrooxidans culture was isolated from soil using the differential iron media i.e. 9K medium and was inoculated into sand filters. At the end of the experiment, the removal efficiency of ferrous iron was about 52% and that of hexavalent chromium was 60.2%. In simultaneous treatment, it was observed that removal efficiency of iron was about 68% while that of hexavalent chromium was about 93% suggesting that slow sand filters were more effective for the removal of hexavalent chromium than iron. Hence, the designed slow sand filters were able to reduce the concentration of hexavalent chromium more efficiently than ferrous iron. And it was observed that slow sand filters can effectively remove ferrous iron and hexavalent chromium from water if they are inoculated with respective bacteria. Key,words,. Hexavalent Chromium, Iron Oxidizing, Sand Filters, Acidothiobacillus ferrooxidans, waste management.