In this paper, the commercial anion exchange resin (IRA900) was used to investigate the adsorption properties, comparing the anion selectivity of phosphate and sulfate in water. The phosphate removal efficiency was 29.6% less than sulfate in single condition, and significantly decreased from 44.8% to 3.47 in mixed conditions while sulfate removal efficiency remained unchanged, confirming a higher selectivity for sulfate over phosphate. In the pH effect, phosphate removal efficiency increased with increase of pH due to the increased HPO4 2- species. The total removal efficiency of phosphate and sulfate was obtained approximately 62% in mixed condition, regardless of solution pH, indicating that the total anion exchange capacity was not influenced in the pH. The values of qmL and bL derived from Langmuir isotherm equation were 11.5 and 8.10 times higher for sulfate than for phosphate in mixed conditions. In single condition, sulfate and phosphate reached to equilibrium at 6 and 3 h, respectively. In mixed condition, phosphate was desorbed by the sulfate after 1h and the time to equilibrium for sulfate was retarded to 6h. Furthermore, when comparing the separation factor (αP/S), increasing the initial concentration led to higher selectivity of phosphate.

This study aimed to remove uranium (U(VI)) ions from sulfate-based acidic soil-washing effluent using the ion-exchange method. For effective ion exchange of U(VI) ions under acidic conditions, one chelate resin (Purolite S950) stable under low pH conditions and two anion-exchange resins (Ambersep 400 SO4 and 920U SO4) used in sulfuric acid leaching systems were selected. The exchange performance of the three selected ion-exchange resins for U(VI) ions was evaluated under various experimental conditions, including ion-exchange resin dosages, pH conditions, reaction times, and reaction temperatures. U(VI) ion exchange was consistent with the Langmuir model and followed pseudo-second-order kinetics. Thermodynamic experiments revealed that the U(VI) ion exchange by the ion-exchange resins is an endothermic and spontaneous process. On the other hand, U(VI) ions was effectively desorbed from the ion-exchange resins using 0.5 M H2SO4 or Na2CO3 solution. Overall, on the basis of the results of the present study, we propose that Purolite S950, Ambersep 400 SO4, and Ambersep 920U SO4 are ion-exchange resins that can be practically applied to effectively remove U(VI) ions from sulfate-based acidic soil-washing effluents.

Recently, self-healing concrete has been researched as maintenance and repair of concrete structures are important challenges we face. This paper focused on possibility of ion exchange resin as a novelty material directly and actively controlling harmful ions of concrete, whereas most self-healing concrete researches have been focused on methods to automatically filling and repairing internal crack of concrete. Because equilibrium properties between ion exchange resin and harmful ion is important before design of cement mixing proportion, it was conducted to remove chloride or sulfate in saturated Ca(OH)2 solutions containing NaCl or Na2SO4. The removal performance was analyzed using kinetic equation and isothermal equation. Consequently, the removal properties of anion exchange resin were relatively more dependent on pseudo second reaction equation and Langmuir equation than pseudo first reaction equation and Freundlich equation. And it was concluded that each chloride and sulfate can be removed to the maximum 1068 ppm and 1314 ppm.

In this study, sulfate reduction reaction was used to increase the decomposition of organics, which is the most critical factor for the stabilization of a landfill site. Composite of sewage sludge, papers, and incineration ashes was used in the column. The experimental results indicated that out of 10 reactors, the reactors 3, 4, 8, and 9 showed higher organics (i.e., TOC) removal rate than that in the absence of sulfate. The organics removal rates (K) in R3 and R9 were 8.65e-4/d and 3.82e-4/d, respectively. The times to reach 10% of initial concentrations in R3 and R9 was 7.3 and 16.5 years, respectively, showing faster organics decomposition rates in these reactors.