Carbonate adsorption on goethite in competition with phosphate

摘要: Abstract Competitive interaction of carbonate and phosphate on goethite has been studied quantitatively. Both anions are omnipresent in soils, sediments, other natural systems. The PO 4 –CO 3 binary systems containing 0–0.5 M (bi)carbonate, showing the change concentration as a function pH, concentration, loading. In addition, single ion have used to study adsorption pH initial (H)CO concentration. experimental data described with charge distribution (CD) model. distributions inner-sphere surface complexes calculated separately using equilibrium geometries complexes, which optimized molecular orbital calculations applying density functional theory (MO/DFT). CD modeling, we rely for recent parameters from literature. For carbonate, speciation affinity constants found by modeling competitive effect CO –PO obtained can also predict absence very well. A combination inner- outer-sphere complexation is found. dominated bidentate complex, (FeO) 2 CO. This binuclear complex be present two different that may IR behavior. At high loading Na + interacts ion, probably an fashion. binding constant representative Na–carbonate solution. Outer-sphere formation unimportant. comparable of, e.g., SO 2− SeO .