A novel wastewater purification material was prepared by a hydrothermal method. It was mainly made from oyster shells with the merits of long service time, large surface area, high lead removal efficiency and excellen...A novel wastewater purification material was prepared by a hydrothermal method. It was mainly made from oyster shells with the merits of long service time, large surface area, high lead removal efficiency and excellent recyclable properties. The technological conditions were decided respectively based on the lead removal efficiencies. At pH = 5 and 30 ℃, for the wastewater with the initial concentration of Pb2＋ to be 5 mg/L, adsorption time 24 h, and 1 mg to 40 mL of mass ratio between adsorbent and Pb2＋, the maximum adsorption capacity can reach 0.19 mg/g. The lead removal material prepared by hydrothermal method has excellent recycle performance. The equilibrium adsorption capacity can get to 9.71 mg/g and the average Pb2＋ removal rate is as high as 66.39%. After reusing for 60 times, the SEM observation shows that the hydrates of reticular formation is formed after hydrothermal modification, which provides a good attachment position for Pb2＋, indicating the physical adsorption is dominant.展开更多
Oyster shells have received attention for use as a calcium resource. For this study, calcium phosphate was prepared from phosphoric acid and oyster shells. The influences of the concentration of phosphoric acid and pH...Oyster shells have received attention for use as a calcium resource. For this study, calcium phosphate was prepared from phosphoric acid and oyster shells. The influences of the concentration of phosphoric acid and pH in the preparation conditions were studied from the yields of calcium phosphate and unreacted carbonate, and the Ca/P ratios in precipitates. The yield of calcium phosphate and carbonate was low in the preparation condition with 0.1 mol/l of phosphoric acid. The obtained precipitates were the mixture of calcium hydrogen phosphate dihydrate and the unreacted calcium carbonate. The reactivity of the oyster shells with phosphoric acid was discussed from the yields and Ca/P ratios in precipitates.展开更多
基金Supported by the National Natural Science Foundation of China (No. 51102047)the Natural Science Foundation of Fujian Province (No. 2011J01291)+1 种基金"Green Future" program of China Environmental Protection FoundationScientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry (SRF for ROCS, SEM)
文摘A novel wastewater purification material was prepared by a hydrothermal method. It was mainly made from oyster shells with the merits of long service time, large surface area, high lead removal efficiency and excellent recyclable properties. The technological conditions were decided respectively based on the lead removal efficiencies. At pH = 5 and 30 ℃, for the wastewater with the initial concentration of Pb2＋ to be 5 mg/L, adsorption time 24 h, and 1 mg to 40 mL of mass ratio between adsorbent and Pb2＋, the maximum adsorption capacity can reach 0.19 mg/g. The lead removal material prepared by hydrothermal method has excellent recycle performance. The equilibrium adsorption capacity can get to 9.71 mg/g and the average Pb2＋ removal rate is as high as 66.39%. After reusing for 60 times, the SEM observation shows that the hydrates of reticular formation is formed after hydrothermal modification, which provides a good attachment position for Pb2＋, indicating the physical adsorption is dominant.
文摘Oyster shells have received attention for use as a calcium resource. For this study, calcium phosphate was prepared from phosphoric acid and oyster shells. The influences of the concentration of phosphoric acid and pH in the preparation conditions were studied from the yields of calcium phosphate and unreacted carbonate, and the Ca/P ratios in precipitates. The yield of calcium phosphate and carbonate was low in the preparation condition with 0.1 mol/l of phosphoric acid. The obtained precipitates were the mixture of calcium hydrogen phosphate dihydrate and the unreacted calcium carbonate. The reactivity of the oyster shells with phosphoric acid was discussed from the yields and Ca/P ratios in precipitates.
