Oxidation by Fenton like reactions (Fe3+/H2O2) is economically process for destructive hazardous pollutants in waste water. The effects of different parameters such as, amaranth red dye, ferric chloride, hydrogen pero...Oxidation by Fenton like reactions (Fe3+/H2O2) is economically process for destructive hazardous pollutants in waste water. The effects of different parameters such as, amaranth red dye, ferric chloride, hydrogen peroxide concentrations, pH value of solution, temperature and the presence of inorganic ions (carbonate, nitrate, chloride) on oxidative decolorization of amaranth were investigated. Amaranth degradation by (Fe3+/H2O2) reagent was found to follow first order kinetic model. Under optimum condition, pH = 2.6 and [FeCl3] = 3.75 × 10-4 mol·dm-3, the amaranth in aqueous solution with an initial concentration of 5 × 10-5 mol·dm-3 was degraded by 95% within 6 minutes. Increasing temperature in the range of 298 - 308 K increases the rate of dye degradation. Thermodynamic constants, ΔH*, ΔS* and ΔG* were evaluated. The results implied that the oxidation process was favorable and endothermic.展开更多
There is a major concern among scientists over the elevated levels of arsenic (As) in drinking water in Bangladesh and some parts of India. Investigating the release of As from water filter sludge in soil and its upta...There is a major concern among scientists over the elevated levels of arsenic (As) in drinking water in Bangladesh and some parts of India. Investigating the release of As from water filter sludge in soil and its uptake by plants may provide information about the management of As contaminated filter sludge. In this macrocosm study, iron based sludge con- taining granular ferric hydroxide (GFH) was mixed with air dried silt loam surface soil at rate of 0 (control, no sludge), 1.5 and 2.5 t?ha?1 and red amaranth (Amaranthus tricolor L.) plants were grown for 45 days. Addition of filter sludge did not affect the height, fresh weight and dry matter yield of amaranth. However, the highest concentration of As and Fe were found both in shoots and roots of amaranth grown in the pot of the highest rate of sludge treated soil. The con- centration of As, Fe and S was higher in the roots than that in the shoots of Amaranth. Translocation of As, S and Fe in- creased with the rates of sludge application. Elevated concentration of As in sludge treated plants is a sign of environ- mental hazard and should be taken into consideration.展开更多
文摘Oxidation by Fenton like reactions (Fe3+/H2O2) is economically process for destructive hazardous pollutants in waste water. The effects of different parameters such as, amaranth red dye, ferric chloride, hydrogen peroxide concentrations, pH value of solution, temperature and the presence of inorganic ions (carbonate, nitrate, chloride) on oxidative decolorization of amaranth were investigated. Amaranth degradation by (Fe3+/H2O2) reagent was found to follow first order kinetic model. Under optimum condition, pH = 2.6 and [FeCl3] = 3.75 × 10-4 mol·dm-3, the amaranth in aqueous solution with an initial concentration of 5 × 10-5 mol·dm-3 was degraded by 95% within 6 minutes. Increasing temperature in the range of 298 - 308 K increases the rate of dye degradation. Thermodynamic constants, ΔH*, ΔS* and ΔG* were evaluated. The results implied that the oxidation process was favorable and endothermic.
文摘There is a major concern among scientists over the elevated levels of arsenic (As) in drinking water in Bangladesh and some parts of India. Investigating the release of As from water filter sludge in soil and its uptake by plants may provide information about the management of As contaminated filter sludge. In this macrocosm study, iron based sludge con- taining granular ferric hydroxide (GFH) was mixed with air dried silt loam surface soil at rate of 0 (control, no sludge), 1.5 and 2.5 t?ha?1 and red amaranth (Amaranthus tricolor L.) plants were grown for 45 days. Addition of filter sludge did not affect the height, fresh weight and dry matter yield of amaranth. However, the highest concentration of As and Fe were found both in shoots and roots of amaranth grown in the pot of the highest rate of sludge treated soil. The con- centration of As, Fe and S was higher in the roots than that in the shoots of Amaranth. Translocation of As, S and Fe in- creased with the rates of sludge application. Elevated concentration of As in sludge treated plants is a sign of environ- mental hazard and should be taken into consideration.
文摘以苋菜为原料,采用溶剂浸提法和超声波萃取法从苋菜中提取苋菜红色素,对提取工艺条件及色素稳定性进行了研究.单因素实验、正交试验及苋菜红色素对光、热和pH稳定性实验的结果表明:超声波法提取的苋菜红色素较浸提法提取的色素得率高、稳定性好;超声法提取苋菜红色素的最佳工艺条件:超声波功率400W、料液比1∶4、温度40℃、超声时间20 min.
