A Comparative Study of the Biosorption of Iron(III)—Cyanide Complex Anions to Rhizopus arrhizus and Chlorella vulgaris

ABSTRACT

In this study a comparative biosorption of iron(III)—cyanide complex anions from aqueous solutions to Rhizopus arrhizus and Chlorella vulgaris was investigated. The iron(III)—cyanide complex ion-binding capacities of the biosorbents were shown as a function of initial pH, initial iron(III)—cyanide complex ion, and biosorbent concentrations. The results indicated that a significant reduction of iron(III)—cyanide complex ions was achieved at pH 13, a highly alkaline condition for both the biosorbents. The maximum loading capacities of the biosorbents were found to be 612.2 mg/g for R. arrhizus at 1996.2 mg/L initial iron(III)—cyanide complex ion concentration and 387.0 mg/g for C. vulgaris at 845.4 mg/L initial iron(III)—cyanide complex ion concentration at this pH. The Freundlich, Langmuir, and Redlich-Peterson adsorption models were fitted to the equilibrium data at pH 3, 7, and 13. The equilibrium data of the biosorbents could be best fitted by all the adsorption models over the entire concentration range at pH 13.     

The effect of using group decision support systems in value management studies: An experimental study in Hong Kong

A group decision support system (GDSS) can be helpful to VM users overcome difficulties in value management (VM) workshops. A web-based GDSS known as interactive value management system (IVMS) is introduced in this paper. A comparative experimental study is undertaken to investigate the extent to which the use of IVMS can improve the performance of VM workshops by using a competing value approach (CVA). This study compares and contrasts the performance of a traditional VM workshop with an IVMS-supported VM workshop in three aspects: (1) process measures, (2) outcome measures, and (3) participants’ satisfaction. The process measures indicate that IVMS is helpful in improving the efficiency, information reliability and supportability of decision and participation process, while the outcome measures show groups supported by IVMS perform better in ideas generations. The results also indicate that the use of GDSS results in increasing participant satisfaction.     

STUDY ON THE POLYMERIZATION DEGREE OF SILICATE ANIONS IN THE SILICATE GLASS BY TRIMETHYLSILYLATION METHOD

In the present paper,a mixed solvent methodis applied to the trimethylsilylation of silicateglass,and the polymerization degree and itsdistribution of silicate anions in the silicateglass are measured by means of the analyses ofgas chromatography-mass spectrography.     

The effect of electrolyte anions incorporated into anodic oxide films on the experimental transport numbers of ions

The growth of barrier anodic film is considered theoretically with regard to the migration of three ionic carriers: oxygen and metal ions and electrolyte anions. It is shown that the consideration of anion transport leads to the conclusion that the film grows at three interfaces: the metal/oxide and oxide/electrolyte interfaces and the interface between an oxide layer containing electrolyte anions (contaminated layer) and the oxide layer free of them (“pure” layer). The error in the measured transport numbers of metal and oxygen, which is caused by ignoring a contribution of electrolyte anions to the total charge transport, is maximum in the absence of anion motion.     

离子色谱法测定饮用水中的溴酸盐、亚氯酸盐、氯酸盐及常规阴离子含量

研究大体积直接进样化学抑制电导-离子色谱法同时测定饮用水中溴酸盐、亚氯酸盐、氯酸盐以及其他7种常规无机阴离子的分析方法。采用IonPac AS9-HC分离柱和IonPac AG9-HC保护柱,以12mmol/L Na2CO3溶液为淋洗液,流速1.0mL/min,一次进样100μL。结果表明:该方法 18min内能检测出10种阴离子,各离子加标回收率为93.0%～103.1%;标准曲线的相关系数为0.9993～0.9999,相对标准偏差为1.07%～4.98%。该方法具有灵敏、准确、快速等优点,在优化条件下将该方法用于测定昆明市自来水和多种市售瓶装饮用水,结果较满意。     

离子色谱法测定焦化废水中的Cl-、NO3-、SO42-、S2O32-和SCN-

研究了用离子色谱法同时测定焦化废水中的Cl-、NO3-、SO24-、S2O23-和SCN-的含量。以Na2CO3-NaHCO3为流动相,乙腈为有机改进剂,自动进样器进样,待测离子经Metrosep A SUPP 5阴离子交换柱分离,抑制电导检测。实验优化了流动相组分的配比、有机改进剂的种类和浓度以及淋洗速度对分离效果的影响。在优化实验条件下,该方法线性相关性好(R>0.998 9),灵敏度高,检出限在0.06～0.28 mg/L范围内,精密度好(RSD<3.1%)。将该方法应用于焦化废水中无机阴离子的测定,并进行加标回收试验,回收率在89.4%～104.7%之间,结果令人满意。该方法操作简单、速度快、选择性好、准确度高,适合大批量工业废水中多种阴离子成分的同时测定。     

离子色谱法测定化工装置冷凝水中的有机酸

运用离子色谱分析技术,采用亲水性阴离子分离柱,氢氧化钾做淋洗液梯度淋洗,前处理柱进行前处理,对化工装置冷凝水中的有机酸根离子进行了同时分离和电导检测,同时对该方法进行了综合评价,得到令人满意的结果。该方法重复性和再现性相对偏差小于4%,相关系数大于0.999,回收率在86.65%~107.64%,具有简便、准确、检测灵敏度高、分离效果好等特点,随着离子色谱技术的发展,离子色谱法检测有机酸将得到广泛的应用。     

离子色谱法测定酒中的有机酸和无机阴离子

建立用离子色谱/电导检测法测定酒类中有机酸和无机阴离子的分析方法。样品经水稀释,经0.45 μm滤膜过滤后直接进样检测;选用Ionpac AS11阴离子交换分离柱,氢氧化钾淋洗液梯度洗脱,流速1.0 mL/min,以抑制电导检测器检测。该方法对11种有机酸和5种无机阴离子具有良好的线性,相关系数在0.9909~0.9997之间;准确度和精密度良好,样品加标回收率在81.0~117.8%之间,RSD小于5.0%;检出限低,在0.015~0.152 mg/L之间。该方法线性范围广,准确性和精密度良好,操作较简便,结果满意,能满足日常检验要求。     

Acidification of Georgian Bay Rivers Estimated by Modifications of the Wright-Henriksen Model

Data on major ions in the spring freshet of 19 rivers tributary to Georgian Bay were applied to modifications of the Wright-Henriksen model to obtain two estimates of acidification, loss in alkalinity and net SO₄^2?, above background levels. Δ Alkalinity estimates, averaged for all rivers, were 107–147 μeq.L^?1 for various modifications and Net SO₄^2? estimates averaged 108–125 μeq.L^?1. Both measures of acidification increased with proximity to Sudbury. The decrease in alkalinity, 45–166 μeq.L^?1 for the 19 rivers, was related to this spatial variability in atmospheric acid loadings, while the pH decrease, 0.2–1.6 units, reflected as well the original buffering of each river. Organic anions were important in achieving cation-anion balances, in interpretation of pH, and in modification of the Wright-Henriksen model.