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391.
The present work deals with the As(Ⅴ) removal from an aqueous medium by calcined refractory grade bauxite (CRB) as a function of solution pH, time, As(Ⅴ) concentration and temperature. The residual As(Ⅴ) was lowered from 2 mg/L to below 0.01 mg/L in the optimum pH range 4.0-7.0 using a 5 g/L CRB within 3 h contact time. The adsorption data fits well with Langmuir isotherm and yielded Langmuir monolayer capacity of 1.78 mg As(Ⅴ)/g of CRB at pH 7.0. Presence of anions such as silicate and phosphate decreased As(Ⅴ) adsorption efficiency. An increase temperature resulted a decrease in the amount of As(Ⅴ) adsorbed by 6%. The continuous fixed bed column study showed that at the adsorbent bed depth of 30 cm and residence time of 168 min, the CRB was capable of treating 340 bed volumes of As(V) spiked water (C0 = 2 mg/L) before breakthrough (Ce = 0.01 mg/L). This solid adsorbent, although not reusable, can be considered for design of adsorption columns as an efficiency arsenic adsorption media. 相似文献
392.
Loofa sponge (LS) immobilized biomass of Chlorella sorokiniana (LSIBCS), isolated from industrial wastewater, was investigated as a new biosorbent for the removal of Cr(Ⅲ) from aqueous solution. A comparison of the biosorption of Cr(Ⅲ) by LSIBCS and free biomass of C. sorokiniana (FBCS) from 10-300 mg Cr(Ⅲ)/L aqueous solutions showed an increase in uptake of 17.79% when the microalgal biomass was immobilized onto loofa sponge. Maximum biosorption capacity for LSIBCS and FBCS was found to be 69.26 and 58.80 mg Cr(Ⅲ)/g biosorbent, respectively, whereas the amount of Cr(Ⅲ) ions adsorbed onto naked LS was 4.97 mg/g. The kinetics of Cr(Ⅲ) biosorption was extremely rapid and equilibrium was established in about 15 and 20 min by LSIBCS and FBCS,respectively. The biosorption equilibrium was well defined by Langmuir adsorption isotherm model. The biosorption kinetics followed the pseudo-second order kinetic model. The biosorption was found to be pH dependent and the maximum sorption occurred at the solution pH 4.0. Desorption studies showed that 98% of the adsorbed Cr(Ⅲ) could be desorbed with 0.1 mol/L HNO3, while other desorbing agents were less effective in the order: EDTA > H2SO4 > CH3COOH > HCl. The regenerated LSIBCS retained 92.68% of the initial Cr(Ⅲ) binding capacity up to five cycles of reuse in continuous flow-fixed bed columns. The study revealed that LSIBCS could be used as an effective biosorbent for the removal of Cr(Ⅲ) from wastewater. 相似文献
393.
分层填料土地毛管渗滤系统处理生活污水的研究 总被引:3,自引:0,他引:3
研究了煤渣与土壤分层装填的土地毛管渗滤系统处理生活污水的效果;该系统未种植物前的运行初期,进水溶解氧浓度的增加可促进好氧微生物的生长繁殖,使其较快处于稳定期;在系统运行稳定后,在装置表面种植了植物,进水溶解氧浓度的减少对系统去除污染物效果的影响不明显;在出水达到国家二级排放标准的情况下,该系统所能承受的最高水力负荷为0.2m/d,与常规的纯土壤地下渗滤系统运行水力负荷仅能<0.05m/d相比,提高了单位面积处理污水的能力,节省了占地面积。 相似文献
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396.
The steam explosion is one of the most serious accidents in the metallurgical industry. In this paper, an experimental study on the interaction of molten copper column with cooling water was carried out using high-speed camera and transient pressure measurement system. The effects of temperature, falling height, diameter and mass of molten copper column on the interaction were investigated. The steam cavity phenomenon was observed in the interaction and the percentage of steam cavity volume affects the probability of fragmentation of molten copper column. The maximum percentage of steam cavity volume increases firstly and then decreases with the increase of temperature and falling height. It increases with the increase of diameter of molten copper column, but the mass has a weak effect. The pressure wave generated by the interaction of molten copper column with cooling water gradually increases with an increase in the temperature of molten copper column. The energy conversion rate in the interaction of molten copper column with cooling water was calculated. The rate of energy conversion from the thermal energy of molten copper column to the energy of pressure wave is low because most of the thermal energy is dissipated into the cooling water by heat transfer. 相似文献
397.
通过实验确定用2,4-二硝基苯肼吸附管的涂渍方法测定醛酮类化合物;比较了C18柱、佛罗里硅藻土柱及硅胶柱对DNPH的涂渍效率和乙腈对醛酮腙的洗脱效率。结果表明:硅胶柱对DNPH涂渍效率及对醛酮腙的洗脱效率高,是制备2,4-二硝基苯肼吸附柱的最佳填充柱。 相似文献
398.
399.
周亚军 《安全.健康和环境》2009,9(3):22-24
介绍了填料型减压塔的腐蚀及停工检修程序,针对填料型减压塔检修时硫化亚铁自燃事故,提出了预防硫化亚铁自燃的措施。 相似文献
400.