Adsorption of phosphorus pollutant from water and wastewater by ferrihydrite-modified diatomite

点击翻译按钮获取中文摘要

This research project is to further understand the mechanisms of an efficient phosphorus adsorbent material known as ferrihydrite-modified diatomite (FHMD) developed in my previous work and explore the ways and conditions for successful field application of this novel adsorbent for removal and stabilization of phosphorus pollutant in lake water.**Dissolved phosphorus pollutant is the growth limiting nutrient and therefore is the main determinant in phytoplankton growth and eutrophication in surface water bodies. As the results of dissolved phosphorus discharge from various point sources of municipal and industrial wastewater effluents and non-point sources of agricultural and urban runoff, eutrophication in inland lakes and streams has become one of the most serious threats to water environmental quality in Canada and many other countries. It can significantly impair water use. A feasible technology for removing phosphorus pollutant from water must be developed to alleviate the eutrophication. The phosphorus removal via adsorption process is recommended because it can be operated easily in lakes.**FHMD developed in my previous research is formed through the deposition of Si-containing ferrihydrite into pores of diatomite. FHMD is an efficient phosphorus adsorbent because it has a Brunauer-Emmett-Teller specific surface area of 211 sq. m/g and has a phosphorus adsorption capacity of 37.3 mg-P/g. The phosphorus adsorption capacity of FHMD is substantially greater than other conventional low-cost adsorbents. In order to obtain the optimum adsorption capacity, synchrotron X-ray absorption near edge structure spectroscopy (XANES) has been employed to optimize the conditions to synthesize FHMD with the least crystalline ferrihydrite and the largest surface area. As an efficient and environmentally safe phosphorus adsorbent, FHMD can be applied to lake eutrophication control. Lake enclosure experiments will be conducted in a eutrophic lake to evaluate performance of the adsorption process and estimate cost benefits of FHMD.**