Phosphate removal by iron oxide-coated diatomite: Laboratory test of a new method for cleaning drainage water

摘要: Abstract Transport of phosphate (P) in drainage water from P rich agricultural fields to freshwaters via drains may cause open eutrophication. One way reduce this transport is by installation sorbing filters at drain outlets. As flows and concentrations can be highly fluctuating, suitable must have good hydraulic conductivity high efficiency, i.e. rapid sorption with affinity capacity. To fulfill these requirements, we tested a new concept for filter material design comprising porous stable calcined diatomaceous earth particles (CDE, 2–4 mm) coated thin layers amorphous iron oxide. According NMR MICP analyses the had bimodal pore size distribution average diameters around 1 μm 100 μm. The coating formed film on CDE internal external surfaces markedly increased efficiency. Thus, 0.1 0.5 mg P/L solutions was almost quantitatively sorbed within 1½ min solution:solid ratio 100. SEM-EDX demonstrated that quickly penetrated into structure granules all Fe active bonding. This conceptual investigation demonstrates useful host which oxides precipitated resulting an effective material.