Biosorption characteristics of unicellular green alga Chlorella sorokiniana immobilized in loofa sponge for removal of Cr(Ⅲ)

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.     

土地处理池塘污水影响因素的实验研究

通过户外动态土柱模拟实验,研究了淹水时间、土壤厚度、土壤粒径和淹水深度对池塘污水处理效果的影响。实验结果表明:连续淹水超过4～5d,COD去除率明显下降;相同进水条件下,土层厚度在120cm处,COD去除率达到80%以上;土壤粒径<0.1mm时,COD去除率达到90%;在土层厚度120cm处,淹水深度为60cm时,COD去除率仅40%。     

Steam cavity and explosion intensity of molten copper column interaction with water

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.     

用2,4-二硝基苯肼吸附管涂渍方法测定醛酮类化合物

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。     

水和废水中氯乙烯方法的测定

利用吹扫捕集测量水和废水中氯乙烯检出限低,无溶剂污染,干扰少,结果准确,操作快捷方便。     

填料型减压塔检修时硫化亚铁自燃及预防

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。     

石油类污染物在砂砾石层中的迁移与分布

利用静态模拟实验研究河滩砂砾石对油类的静态吸附特性,确定平稳吸附等温方程。通过土柱实验模拟油类在砂砾石中的迁移过程,建立油类在砂砾石层中迁移的数学模拟模型,确定模型参数,以此预测油类砂砾石中的迁移。     

生物滴滤池法处理有机废气甲苯工艺填料的选择

生物滴滤池法处理挥发性有机污染物的研究是世界工业废气净化的前沿热点之一，本研究比较了阶梯环，聚乙烯小球，煤炭渣和某种活性炭附着纤维作为滴滤池中生物附着载体性能的优劣，结果表明，活性炭附着纤维填料系统具有较好的有机污染物去除能力。     

土柱淋洗实验研究进展及其在土壤有机碳迁移研究中的应用展望

土壤碳库是陆地生态系统碳循环中重要的源与汇,其小幅的变化都将对大气CO2含量造成巨大的反馈.全球约有1 500 Gt的有机碳储存在土壤中,土壤有机碳的迁移转化一直以来是学者们关注的热点问题.土柱淋洗实验在农业、林业、环境科学等研究领域广泛应用,并在土壤溶质运移模拟、土壤水文性质、重金属和污染物迁移转化等科学研究中取得了...