Preparation of α-calcium sulfate hemihydrate whiskers with high aspect ratios in presence of a minor amount of CuCl_2·2H_2O

In order to produceα-calcium sulfate hemihydrate(α-CaSO4·0.5H2O)whiskers with high aspect ratios,a minor amount of CuCl2·2H2O was used as the modifying agent in the process of hydrothermal treatment of calcium sulfate dihydrate(CaSO4·2H2O)precursor.The presence of 2.60×10–3 mol/L CuCl2·2H2O resulted in the increase of the aspect ratios ofα-CaSO4·0.5H2O whiskers from 81 to 253.The preferential adsorption of Cu2+on the negative{110}and{100}facets ofα-CaSO4·0.5H2O crystal structures was confirmed by EDS and XPS.And ATR-FTIR demonstrated the ligand adsorption of Cu2+on the surface ofα-CaSO4·0.5H2O whiskers.The experimental results reveal that the whiskers with high aspect ratios are attributed to the adsorption of Cu2+,which promotes the 1-D growth ofα-CaSO4·0.5H2O whiskers along the c axis.

Contacted Ion Pairs in Aqueous CuCl2 by the Combination of Ratio Spectra, Difference Spectra, Second Order Difference Spectra in the UV-Visible Spectra

The microstructure of aqueous CuCl2 has been studied through lots of technologies for many years; however, it remains a controversial subject. In this study, a new spectroscopic method has been proposed to analyze the UV-visible spectra of thin fihn of CuCl2/H2O solutions at different concentrations. This method is the combination of ratio spectra, difference spectra and second order difference spectra. By using this method, two new bands at -230 and -380 nm are obviously observed. The bands are assigned as the contacted ion pairs [CuCl3（H2O）n]- or [CuCl4（H2O）n]2-, which demonstrates that ion pairs exist in the CuCl2/H2O solution. Such finding agrees with the recent theoretical spectra obtained by time-dependent density functional theory. Furthermore, the populations of the contacted ion pairs are discussed. This study not only offers the direct spectroscopic evidence of [CuCl3（H2O）n]- or [CuCl4（H2O）n]2- in aqueous CuCl2, but also suggests that the spec- troscopic analysis method is powerful to extract the weak bands in a strong overlapping spectrum.

Effects of MgO content and CaO/Al_2O_3 ratio on surface tension of calcium aluminate refining slag

Surface tension of calcium aluminate refining slag was measured by the Slide method at 1823 K.Based on different levels of the MgO content and the mass ratio of CaO to Al_2O_3,the effects of MgO content and the mass ratio of CaO to Al_2O_3 on surface tension were investigated.The results indicate that surface tension decreased with increasing MgO content(from 0 to 4.86%),followed by an increase with further increasing MgO content up to 11.33%.The trend that surface tension changed with the mass ratio of CaO to Al_2O_3 was the same as the trend that surface tension changed with the MgO content.The surface tension was varied from 0.617 N/m to 0.710 N/m,for the mass ratio of CaO to Al_2O_3 varying between 0.60 and 1.28.An attempt was made to estimate surface tension of CaO-Al_2O_3-MgO slag and its sub-system,and the application showed that the model worked well.

H_2O_2对COD测定的干扰及消除研究

COD是表征水体有机物污染状况的重要参数,而实际水样成分复杂往往对COD测定产生干扰,其中H2O2尤为明显。通过实验分析H2O2对COD干扰状况并提出消除干扰的措施。研究表明,H2O2作为还原剂使COD测定值高于实际值;H2O2浓度与COD之间呈现线性关系,R2为0.999 7,线性方程为y=0.466 4x+0.249 5,1mg的H2O2能引起0.466 4mg的COD变化。在低、高2种浓度的COD标准溶液体系中,线性方程计算的ΔCOD1(即H2O2引起的COD变化值)与ΔCOD2(COD测定值与原水COD的差值)差值为原水COD的1.28%～11.80%、0.16%～5.95%;在低、高2种浓度的工业废水体系中,线性方程计算的ΔCOD1与ΔCOD2差值分别为0.1～5.9、32.7～75.6mg/L,为原水COD的1.28%～14.00%、2.35%～5.44%;在生活污水体系中,线性方程计算的ΔCOD1与ΔCOD2差值为6.8～30.3mg/L,为原水COD的2.98%～13.40%。通过线性方程,较好地反映出实际的COD差异,可以消除H2O2对COD测定的干扰。该方法简单准确,能够较好地反映实际水样的COD情况。

高级氧化法中H_2O_2对COD的测定影响及消除

通过测定含不同H2O2浓度的纯水体系及硝基苯类化合物水样体系的废水化学需氧量(COD),分析发现硝基苯类化合物水样中H2O2对COD的测量存在正干扰,且具有很好的线性关系。在不引入新的干扰前提下,探讨了相应的H2O2消除方法。结果表明,当水样中H2O2浓度475 mg·L-1,COD值为747.6 mg·L-1时,改变水样p H值为碱性有利于H2O2的去除;添加二氧化锰催化剂虽然能在较短时间内去除H2O2,但可能引入新的干扰物;添加过氧化氢酶在不引入新的干扰情况下可快速去除H2O2。当反应时间3 min,分别调节水样p H为12、添加二氧化锰、添加过氧化氢酶,水样中H2O2去除率为1.2%、45.6%、100%。在相同酶量下处理含不同浓度H2O2的水样,H2O2均可在短时间内被除净。分析表明,添加过氧化氢酶可为快速、高效消除废水中未知浓度H2O2对CODCr测定的影响提供一条新的途径。

低强度超声波对残留H2O2的去除

化学需氧量（COD）会受到来自众多高级氧化技术中添加的过氧化氢（H2O2）的干扰。为了评估低强度超声波辐射结合清除剂（Na2CO3或Na HCO3）分解水样中残留H2O2的可行性,对去离子水、葡萄糖模拟废水和印染废水二级处理出水进行超声（超声波频率为39 k Hz,功率分别为75 W、112.5 W和150 W）处理,H2O2质量浓度为20 mg/L,时间为60 min或80 min,清除剂用量为50 g/L。以20 min的间隔测定H2O2质量浓度和COD。结果表明,COD与H2O2质量浓度的比值取决于废水的性质,去离子水、葡萄糖模拟废水和印染废水二级处理出水的比值分别为0.262 6 mg COD/mg H2O2、0.209 9 mg COD/mg H2O2、0.401 3 mg COD/mg H2O2。超声辐照对去除H2O2有一定的影响,但在去离子水中超声功率为150 W、60 min时的去除率最高,仅为18.1%。超声辐照联合清除剂Na2CO3或Na HCO3的效果更显著。对于印染废水二次处理出水,加入Na HCO3作为羟自由基清除剂,80 min时H2O2去除率达到97.3%。然而,由于Na HCO3和H2O2形成的高度氧化的超氧离子能降解废水中的有机物质,水样的实际COD降低。用超声辐射结合Na2CO3处理80 min,将COD的测定值与通过COD、H2O2质量浓度比值得到的计算值进行比较,以确认经超声波联合Na2CO3处理的印染废水二级处理出水中的有机物未降解。研究表明,超声波照射与Na2CO3结合去除水样中的低浓度H2O2是可行的。

碳酸钠催化超声波去除水样残留H2O2的动力学探究

使用碳酸钠催化超声波作为COD测定的预处理方法,消除使用重铬酸钾法测定COD时,水样中残留的H2O2可与重铬酸钾反应,使结果偏高或混淆滴定终点的影响,并且考察了不同初始浓度的H2O2和碳酸钠投加量对去除H2O2的影响。结果表明,超声波结合碳酸钠可以在80min内有效地去除H2O2;H2O2分解速率符合一级反应动力学方程;碳酸钠投加量存在饱和点,投加量不高于5.4g/L时,随着投加量的增加,H2O2分解速率增加;当投加量高于5.4g/L时,H2O2分解速率不随投加量的增加而增加。

化学浆漂白得率与COD之间的相关性

根据理论上木素含量和OXE(Oxidation equivalents)的关系可推断出纸浆得率损失与废水COD之间的相关关系。研究发现,对不同的氧脱木素浆,纸浆得率损失与COD之间的比值都非常接近;COD与纸浆得率损失的比值为0.9。抽提段采用剧烈条件并提高O2和H2O2的用量会增加废水负荷和降低纸浆得率。在较高的抽提温度下,添加较多的H2O2会降解更多的纤维素,这使得COD与纸浆得率损失的比值更接近于1。

A NEW METHOD OF COMPUTING MULTI-COMPONENT E-pH DIAGRAMS

Aqueous E pH Diagram is an essential tool for analyzing hydrometallurgical and corrosion processes. Due to the requirements for environmental protection and energy saving in recent years, waste water processing and hydrometallurgical process of concentrate have been greatly developed. The construction of E pH diagrams has turned to multi component systems. However, there are some limits in plotting such diagrams. There is only one diagram for one multi component system, which can not reflect the truth of the aqueous reaction. In the paper, a new computation method is proposed to construct E pH diagrams. Component activity term is used to determine the boundary of stable areas. For the multi component systems, different atom ratios of elements have been taken into account. M S H 2O system is chosen to study since it is of importance in metallurgical solution. Compared with conventional methods, the algorithm is simple and conforms to real conditions.

Kinetic of Transport of Technogenic Ecotoxicants through Model Membranes

The kinetics of ecotoxicant transport through the membrane was studied. The ecotoxicants studied were pecticides widely used in agriculture: lontrel (clopyralid), sencor (metribuzin), basagran (bentazon), roundup (glyphosate), kusagard (alloxydim sodium), and sethoxydim, as well as lontrel complexes with cobalt and copper. All compounds considered penetrate through the model phosphatidylcholine liposomal membranes. The transfer rate was monitored by fluorescence quenching of ?-ATP inside the liposomes. The mathematical model for the process was proposed, and the mass transfer rates were calculated. The octanol/water partition constants were determined. All the compounds con- sidered were shown to accumulate in the fatty layer. The kinetics of their accumulation was studied, and the rates of accumulation in the nonpolar phase were calculated, which correlate with the complexation constants of the same compounds. Bioaccumulation of the toxicants is caused by the formation of complexes with the fatty phase (lipid part) of the cellular membranes. The toxicants under study transferred into the nonpolar phase with a considerable rate dur- ing the whole observation time, namely, 18 months.

H_2O_2湿式氧化处理含酸性红B染料模拟废水的研究

用H2 O2 作氧化剂 ,在连续式的压力反应器内探索了WPO(过氧化氢湿式氧化法 )、CWPO(催化过氧化氢湿式氧化法 )氧化降解含酸性红B染料模拟废水的过程 ,分别考察温度、压力、氧化剂量及催化剂对反应过程与对象污染物降解的影响规律 .结果表明 ,与常规湿式氧化法相比 ,WPO能在较低的温度和压力下降解结构稳定的有机物 ,在 2 2 0℃、8min、0 1MPa时 ,含1 5 0 0mg·L-1 酸性红B染料模拟废水的COD和色度的去除率分别达到 6 0 5 0 %和 96 80 % .同时发现 ,通过升温和增加过氧化氢的投加量不能够使废水COD和色度的去除率进一步提高 ,故引入Cu2 + 作催化剂来实现CWPO过程 ,在 2 2 0℃、8min、0 1MPa条件下 ,CWPO对同一废水的COD和色度的去除率分别达到 82 5 0 %和 99 71 % .通过计算得出CWPO与WPO相比基于COD的表观活化能降低了 6 5 93 % .

Fe(Ⅲ)-草酸盐络合物/H_2O_2/UV体系对染料废水的处理研究

研究了活性物质 Fe(Ⅲ) -草酸盐络合物和氧化剂 H2 O2 结合起来形成的光催化氧化复合体系对以活性艳红 X- 3B为代表的七种水溶性染料模拟废水的处理。在 2 5 0 W高压汞灯照射下 ,复合体系对初始浓度为 1 0 0 mg/L的染料溶液 ,处理 2 4 min后 ,脱色率均达 90 %以上 ,COD去除率为33%～ 70 %。以活性艳红 X- 3B为对象 ,研究各种反应条件对其处理效果的影响 ,结果表明 :在 p H=3～ 6范围内 ,脱色率速率较大 ;在染料初始浓度为 2 0～ 2 0 0 mg/L范围内 ,脱色速率随浓度增大而降低 ;Fe( Ⅲ ) /草酸盐配比为 40 /2 0 0 ( mmol/L)时脱色效果最好 ;H2 O2 投加量为 4～ 40 mg/L时 ,脱色速率随 H2 O2 投加量的增加而增长较快 ,在 40～ 1 0 0 mg/L时 。

气井钻井废水深度处理实验研究

气井钻井废水是气田开发过程中的一个重要污染源,其污染物成分复杂、分布广,对环境的影响很大。文章以气井钻井废水为处理对象,实验研究了预处理和类Fenton试剂催化氧化法深度处理工艺,考察了Fen ton试剂投加量、反应条件、反应时间等单因数对处理效果的影响,确定了该处理工艺的最佳操作条件为: H2O2 为2500 mg/L,Fe2SO4·7H2O为70 mg/L,pH值为3.5,反应时间为90 min,氧气的通入量为70 min。废水中的主要污染物指标COD的去除率大于80%。

H_2O_2-Fe^(2+)法处理精喹禾灵生产废水的研究

采用酸析法先对精喹禾灵生产废水进行预处理然后用H_2O_2-Fe_^(2+)法进行催化氧化,研究了H_2O_2投加量及投加方式、Fe^(2+)投加量、反应时间对处理效果的影响。结果表明,在H_2O_2投加量为12g/L,分批投加,Fe^(2+)投加量为300mg/L,反应时间为90min、pH=2～4的条件下,氧化,出水经活性炭吸附后废水的COD和色度的去除率分别可达94.5％和96.7％,用石灰乳中和后可直接排放,达到了国家二级排放标准(GB8978-1996)。

催化超临界水氧化偏二甲肼

采用CuO/γ-Al_2O_3和MnO_2/γ-Al_2O_3为催化剂,H_2O_2为氧化剂,在固定床反应器中进行催化超临界水氧化偏二甲肼实验.结果表明,CuO和MnO_2对偏二甲肼的氧化降解具有显著的促进作用.偏二甲肼的去除率随反应温度和压力的升高、停留时间的延长而提高.在24—26MPa、400—450℃条件下,数秒钟内COD去除率可达到99%以上.显示出催化超临界水氧化技术的高效性.催化剂CuO/γ-Al_2O_3的催化效果优于MnO_2/γ-Al_2O_3.进一步研究表明,偏二甲肼催化超临界水氧化为·OH引发的自由基反应,最终氧化产物为CO_2,N_2和H_2O.

O_3和O_3/H_2O_2法氧化处理制药废水的研究

采用O3和O3/H2O2氧化法对某制药厂的制药废水进行氧化处理,主要考察废水的pH值、O3流量、反应时间对COD去除率的影响。结果表明,O3氧化法的最佳条件为:废水的pH值为9.00,O3流量为5 g/h,反应时间为90 min。在此条件下,废水的COD和TOC的去除率分别达到64.16%和75.34%。O3/H2O2氧化法更能有效的提高废水COD和TOC的去除率,但需要合适的H2O2投加量。处理后两者去除率分别达87.45%和91.49%,且处理后的COD值(351 mg/L)符合该厂排入市政管网的要求(500 mg/L),同时废水的可生化性提高,B/C由0.12提高至0.32。对O3/H2O2处理制药废水的反应机制研究表明,COD的去除率随自由基抑制剂浓度的增加而降低,COD的去除主要是体系中.OH的贡献。另外,采用COD和TOC结合起来作为评价指标更能准确的反映出制药废水中有机物的去除规律。

居家糖尿病护理APP平台结合精准护理干预模式对在职2型糖尿病病人血糖及生活质量的影响

[目的]探讨居家糖尿病护理APP平台结合精准护理干预模式对在职2型糖尿病(T2DM)病人的应用效果。[方法]选取在职T2DM病人120例,采用随机数字表法分为对照组和观察组,每组60例。对照组给予常规糖尿病教育和后期定期随访,观察组采用居家糖尿病护理APP平台结合精准护理干预模式实施管理。比较两组干预后6个月的体重指数(BMI)、腰臀比(WHR)、空腹血糖(FPG)、餐后2h血糖(2hPG)、糖化血红蛋白(HbA_1C)、生活质量的变化及6个月内低血糖发生率。[结果]与干预前比较,两组WHR、FPG、2hPG、HbA_1C下降,生活质量提升,干预前后比较差异有统计学意义(P<0.05或P<0.01);与对照组干预后比较,干预后观察组FPG、2hPG、HbA_1C下降,生活质量提升(除社会维度、治疗维度),院外低血糖发生率降低(P<0.05或P<0.01);[结论]居家糖尿病护理APP平台结合精准护理干预,能有效控制在职T2DM病人的FPG、2hPG、HbA_1C水平,降低低血糖发生率,提高病人的生活质量。

UV/草酸铁/H_2O_2法处理乙草胺废水的研究

对UV/草酸铁 /H2 O2 法处理乙草胺废水进行研究 ,考察了H2 O2 浓度、FeSO4浓度、K2 C2 O4浓度、pH值及反应时间对乙草胺去除效果的影响。结果表明 ,当H2 O2 /FeSO4/K2 C2 O4(化学剂量数比 ) =5 0∶5∶1,H2 O2 /乙草胺初始COD(质量浓度比 ) =3∶1时 ,该技术对乙草胺的去除率可达 85 %以上。这表明 ,采用UV/草酸铁 /H2 O2 法可以有效地处理含乙草胺废水。

Fenton试剂处理褐藻胶生产废水

本研究以褐藻胶生产废水为实验对象,实验表明,pH值、反应温度、Fe2+浓度、H2O2浓度以及反应时间五个因素对褐藻胶废水降解效果的影响程度依次是Fe2+浓度>反应时间>反应温度>pH值>H2O2浓度。实验确定的降解褐藻胶废水的最佳条件为Fe2+浓度:4.0m ol/L,反应时间:60m in,反应温度:40℃,pH=3.0,H2O2浓度为0.10m ol/L;在此条件下CO D去除率为59.5%,处理后废水的C O D为60m gO2/L,达到了排放标准。