Papers by Author: Chun Sheng Ding

Abstract: In this experiment quartz sand was chosen as a carrier to be coated by aluminous salt under alkaline condition, and then the specific surface area was tested, and the adsorption capability and Cd²⁺ removal influencing factors of modified sand were studied. The investigation results showed that the specific surface area of modified sand was 75.244m²/g which was 9.38 times of that of original sand; the removal efficiency of Cd²⁺ by aluminous salt modified sand reached 59% contrast to 39% of original sand with pH 7.00. It was also found that the removal efficiency of Cd²⁺ by the aluminous salt modified sand was reduced with the increase of initial concentration of Cd²⁺ solution, and was enhanced with the increase of pH value, the Cd²⁺ removal efficiency was almost 71% with pH 9.0.

Abstract: Ferric salt modified sands were prepared with quartz sand as a carrier and ferric salt coating by the two methods of repeat high-temperature process and repeat alkaline deposition process. The specific surface area of two ferric salt modified sands were detected, and their Pb2+ adsorption capability in different conditions were also described in this paper. The results showed that the specific surface area of ferric chloride and ferric nitrate modified sand was 2.468m2/g and 4.247m2/g respectively, which was 6.910 and 12.612 times more than that of raw quartz sand. In the neutral pH condition, the removal efficiency of Pb2+ by raw quartz sands was approximately 37%, in contrast, the removal efficiency reached 85% by ferric nitrate modified sand and over 90% by ferric chloride modified sand, and it was much higher than that of raw quartz sand.

Abstract: In the study, activated alumina was modified by calcium chloride, and after modification the phosphorus removal from aqueous solution increased by 13% or so. Then the activated alumina with and without treatment were subjected to characterization by the methods of the BET and SEM, and the adsorption characteristics of modified activated alumina were further studied at different contact time, pH values, adsorbent dosage levels and initial phosphorus concentration. Moreover, the equilibrium adsorption data for phosphorus were better fitted to Langmuir adsorption isotherm, and it means that the uptake of phosphorus preferably followed the monolayer adsorption process.

Abstract: To improve the adsorption efficiency of activated carbon for phenol, copper nitrate was used to modify activated carbon. In detail, the absorption properties of modified activated carbon was studied by investigating the effects of adsorption time, pH, amount of modified activated carbon and initial concentration of phenol on the adsorption. And the dynamic and adsorbent model were obtained and explored. It shows that the removal rate of modified activated carbon for phenol was higher than the unmodified carbon, and the best removal rate can be obtained under the conditions of pH about 5, adsorption time of 2h, modified activated carbon dosage of 1.0g. The quasi-two rate equation was better to reflect the dynamics of modified activated carbon for phenol, with the initial concentration of phenol increased, equilibrium adsorption capacity and initial adsorption rate were greater. Both Freundlich and Langmuir model could reflect the adsorption behavior of modified activated carbon for phenol, while the Langmuir model was more properly.

Abstract: To optimize the conditions of modification and understand the absorption mechanism of activated carbon, the orthogonal test was used to select the best conditions of ammonia-modified activated carbon. The changes of activated carbon’s specific surface area, pore volume and surface acidic oxygen-containing functional groups were determined before and after modification by ammonia, and the equilibrium adsorption model for phenol was also explored. The results show that under the conditions of ammonia concentration of 10%, soaking time of 2h, activation time of 2.5h and activation temperature of 500°C, the best removal rate could be obtained. The specific surface area and pore volume of modified activated carbon were increased, whereas the acidic oxygen-containing groups of its surface were significantly reduced by 57.88% after modification. It means the surface polarity of carbon was decreased, and which was conducive to the adsorption of phenol, since phenol was a weakly polar substance. Both Freundlich and Langmuir model could reflect the adsorption behavior of modified activated carbon for phenol, while the Freundlich model was more properly, but for the unmodified activated carbon, Freundlich model was more suited to describe the adsorption behavior of phenol than Langmuir model.