As other natural iron-bearing minerals, schorl could be taken as an effective iron source for degradation of organic pollutants by mineral-catalyzed Fenton-like system. In our present study, the schorl-catalyzed Fento...As other natural iron-bearing minerals, schorl could be taken as an effective iron source for degradation of organic pollutants by mineral-catalyzed Fenton-like system. In our present study, the schorl-catalyzed Fenton-like system has been successfully developed for discoloration of an active commercial dye, Rhodamine B (RhB), in an aqueous solution. Through a number of batch discoloration experiments under various conditions, it was found that the reactivity of the system increased by, respectively, increasing schorl dosage, temperature, hydrogen peroxide starting concentration and by decreasing the pH. Over 90% of discoloration ratio could be gained in less than 30 min, and nearly 70% of total organic carbon (TOC) could be removed in less than 200 min. And, the schorl catalyst could be repeatedly used at least ten times, still with high catalytic activity. Comparative studies indicated that the RhB discoloration ratios were much higher in presence of schorl and H2O2 than those in presence of schorl or H2O2 only, which suggested that the schorl-catalyzed Fenton-like reaction governed the RhB discoloration process. The content of Fe ion leaching in the solution was also measured using inductively coupling plasma-atomic emission spectra (ICP-AES). A mechanism proposed herein suggested that adsorption and Fenton-like reaction (heterogeneous and homogeneous) were responsible for the discoloration of RhB.展开更多
Dyeing wastewater containing methyl orange (MO) could be effectively discolored by schorl-catalyzed Fenton-like system. Experimental results indicated that the MO discoloration ratios could be increased by increasing ...Dyeing wastewater containing methyl orange (MO) could be effectively discolored by schorl-catalyzed Fenton-like system. Experimental results indicated that the MO discoloration ratios could be increased by increasing schorl dosage, temperature, initial H2O2 concentration, and by decreasing solution pH. When the raw schorl and the schorl samples sintered at 750°C, 850°C, 950°C and 1050°C were used as catalyst in Fenton-like system, the MO discoloration ratios obtained were 82%, 31%, 30%, 31% and 7%, respectively. XRD results showed that samples sintered at 750°C, 850°C and 950°C had no change in structure and still held the crystal structure of schorl and quartz, but, the content of schorl crystal decreased. Whereas, schorl crystal completely disappeared in the sample sintered at 1050°C and two new crystal phases of hematite and spinel were formed, which resulted in disappearance of the spontaneous ‘electrostatic poles’. Hence, it was inferred that the electrostatic field of schorl crystal could enhance the MO discoloration by schorl-catalyzed Fenton-like reaction.展开更多
基金Supported by Heilongjiang Science Fundation for Young Scholars (Grant No. QC07C02)Scientific Foundation of Heilongjiang Education Department, China (Grant No. 11531035)
文摘As other natural iron-bearing minerals, schorl could be taken as an effective iron source for degradation of organic pollutants by mineral-catalyzed Fenton-like system. In our present study, the schorl-catalyzed Fenton-like system has been successfully developed for discoloration of an active commercial dye, Rhodamine B (RhB), in an aqueous solution. Through a number of batch discoloration experiments under various conditions, it was found that the reactivity of the system increased by, respectively, increasing schorl dosage, temperature, hydrogen peroxide starting concentration and by decreasing the pH. Over 90% of discoloration ratio could be gained in less than 30 min, and nearly 70% of total organic carbon (TOC) could be removed in less than 200 min. And, the schorl catalyst could be repeatedly used at least ten times, still with high catalytic activity. Comparative studies indicated that the RhB discoloration ratios were much higher in presence of schorl and H2O2 than those in presence of schorl or H2O2 only, which suggested that the schorl-catalyzed Fenton-like reaction governed the RhB discoloration process. The content of Fe ion leaching in the solution was also measured using inductively coupling plasma-atomic emission spectra (ICP-AES). A mechanism proposed herein suggested that adsorption and Fenton-like reaction (heterogeneous and homogeneous) were responsible for the discoloration of RhB.
基金supported by the Natural Science Foundation of Heilongjiang Province, China (Grant No E200906)Scientific Foundation of Heilongjiang Office of Education (Grant No 11531035)the Young Founds of the National Natural Science Foundation of China (Grant No 51002040)
文摘Dyeing wastewater containing methyl orange (MO) could be effectively discolored by schorl-catalyzed Fenton-like system. Experimental results indicated that the MO discoloration ratios could be increased by increasing schorl dosage, temperature, initial H2O2 concentration, and by decreasing solution pH. When the raw schorl and the schorl samples sintered at 750°C, 850°C, 950°C and 1050°C were used as catalyst in Fenton-like system, the MO discoloration ratios obtained were 82%, 31%, 30%, 31% and 7%, respectively. XRD results showed that samples sintered at 750°C, 850°C and 950°C had no change in structure and still held the crystal structure of schorl and quartz, but, the content of schorl crystal decreased. Whereas, schorl crystal completely disappeared in the sample sintered at 1050°C and two new crystal phases of hematite and spinel were formed, which resulted in disappearance of the spontaneous ‘electrostatic poles’. Hence, it was inferred that the electrostatic field of schorl crystal could enhance the MO discoloration by schorl-catalyzed Fenton-like reaction.
文摘采用天然铁电气石作为吸附剂去除水中的恩诺沙星,考察了p H值、干扰离子对吸附性能的影响,并探讨了吸附热力学及动力学特性。结果表明:p H为5的条件下,吸附量最大,为7.13 mg·g^(-1);ΔG<0且ΔH>0表明吸附是自发进行的吸热反应,ΔH=2.048 k J·mol^(-1)(<20 k J·mol^(-1))说明吸附为物理吸附。等温吸附曲线拟合中,Freundlich模型拟合效果较好。电气石对恩诺沙星的吸附过程符合拟二级动力学。脱附实验表明,电气石具有较好的脱附再生性能,脱附率可达99%。初始p H为5时,较高浓度的Cu^(2+)和Zn^(2+)对恩诺沙星的吸附均有抑制作用,Cu^(2+)的抑制作用明显高于Zn^(2+),且干扰离子浓度越高抑制作用越强;p H为7时,低浓度的干扰离子能够促进恩诺沙星的吸附。
