共查询到20条相似文献,搜索用时 656 毫秒
1.
为了研究控制四溴双酚A(TBBPA)臭氧化过程中溴酸盐生成的影响因素,通过实验对不同的水质参数和臭氧投加量条件下臭氧氧化TBBPA过程中溴离子(Br-)及溴酸根离子(BrO3-)的生成量进行了考察。结果表明,臭氧氧化TBBPA生成BrO3-分为两阶段:第一阶段为臭氧氧化降解TBBPA生成Br-,即Br-累积阶段;第二阶段为臭氧化Br-生成BrO3-,即BrO3-生成阶段。Br-及BrO3-的生成量随着TBBPA初始浓度的增加而增加,生成速率随臭氧投加量增加而提高。25~55 ℃条件下反应40 min后,BrO3-生成量随温度升高增加了4.5倍。pH值8~11内,pH值降低对Br-及BrO3-生成量有明显的抑制作用。 相似文献
2.
3.
《水处理技术》2016,(6)
以含溴黄河水为水源,利用中试连续实验,评价臭氧-生物活性炭(O3-BAC)深度处理工艺对COD_(Mn)及嗅味的去除效果,重点研究了臭氧氧化过程中溴酸盐、甲醛等副产物的生成与控制效果。研究发现,O3-BAC工艺能有效降低COD_(Mn)和嗅阈值(TON),在不同水质条件下,臭氧量为2.0 mg/L时溴酸盐的生成量存在超标风险(10μg/L),且导致甲醛大量生成,为29.07μg/L。投加过氧化氢能够有效控制溴酸盐,当氧消耗量为3.0 mg/L以下时,H_2O_2为2.0~3.0 mg/L能将溴酸盐控制在标准内,投加H_2O_2对甲醛生成产生一定影响,随着H_2O_2投加量增加,甲醛生成量先增加后又有所降低。 相似文献
4.
5.
6.
通过纯水的模拟研究,探讨了纳米SnO2和纳米TiO2催化臭氧氧化抑制溴酸盐形成的情况及不同条件下纳米TiO2的抑制效能.结果表明,纳米SnO2催化及纳米TiO2催化均能有效抑制溴酸盐的形成,相对单独臭氧氧化条件溴酸盐生成量分别降低了45.81%和74.10%;光照对纳米TiO2催化抑制溴酸盐形成的效能影响不大;反应温度在10~26℃之间时,随着温度的升高,纳米TiO2催化抑制溴酸盐形成的作用越明显;纳米TiO2催化抑制溴酸盐生成的效能随着Br-初始质量浓度的增加和pH的上升而降低. 相似文献
7.
8.
为了考察饮用水中消毒副产物三氯丙酮(TCAce)的形成过程和影响因素,采用气相色谱-质谱法,以甲基叔丁基醚为萃取剂,1,2-二溴丙烷为内标物,建立了消毒副产物三氯丙酮(TCAce)的测定方法。以L-苏氨酸为前体,考察在不同反应条件下三氯丙酮的生成效果,并探讨了TCAce的形成途径。结果表明:TCAce的生成量在碱性条件下高于中性和酸性条件,在5.5~8.5的pH范围内,随着pH的增大而逐渐提高。在试验条件下,当氯投加量由5.46 ml增加到21.84 ml时,TCAce的生成量随投氯量的增加而增加。当前体物L-苏氨酸投加量由59.6 mg·L-1增加到476.4 mg·L-1时,TCAce的生成量随投加量的增大而减小,当反应温度由10℃增加到30℃时,TCAce的生成量随之增加。HClO氯化L-苏氨酸形成TCAce的过程包含7个步骤,包括取代、氧化、氨基重氮化和还原等复杂的过程。 相似文献
9.
《化工学报》2016,(7)
为了考察饮用水中消毒副产物三氯丙酮(TCAce)的形成过程和影响因素,采用气相色谱-质谱法,以甲基叔丁基醚为萃取剂,1,2-二溴丙烷为内标物,建立了消毒副产物三氯丙酮(TCAce)的测定方法。以L-苏氨酸为前体,考察在不同反应条件下三氯丙酮的生成效果,并探讨了TCAce的形成途径。结果表明:TCAce的生成量在碱性条件下高于中性和酸性条件,在5.5~8.5的p H范围内,随着p H的增大而逐渐提高。在试验条件下,当氯投加量由5.46 ml增加到21.84 ml时,TCAce的生成量随投氯量的增加而增加。当前体物L-苏氨酸投加量由59.6mg·L-1增加到476.4 mg·L-1时,TCAce的生成量随投加量的增大而减小,当反应温度由10℃增加到30℃时,TCAce的生成量随之增加。HCl O氯化L-苏氨酸形成TCAce的过程包含7个步骤,包括取代、氧化、氨基重氮化和还原等复杂的过程。 相似文献
10.
11.
P. P. Budnikoff 《Journal of the American Ceramic Society》1924,7(11):817-820
The different analytical methods proposed for the evaluation of gypsum have been subjected to an experimental test. A combination method, consisting of a fusion with KHCO3 and determination of CaO by KMnO4 titration, the SO3 by Andrews method of titration of BaCrO4 has been found to give very reliable results with the least consumption of time. 相似文献
12.
A novel technique serves to monitor instantaneous rates of loss of a volatile solute from a suspended drop during drying. A highly sensitive electron capture detector is used to monitor concentrations of SF6 released into a flowing gas stream from a suspended, drying drop. Simultaneously, the appearance and morphological development of the drop are monitored with a video camera. This provides the wherewithal of relating instantaneous rates of loss of the volatile solute to particular events during the development of particle morphology.
Initial experiments have been carried out with drops of aqueous solutions of glucose, sucrose, maltodextrin and coffee extract. The results clearly display the onset of the volatiles-retentive selective diffusion phenomenon. There is also substantial loss of the volatile component later in the drying process, when the drops undergo repeated ex ansion, bursting and cratering due to the formation of internaf bubbles. These experiments appear to be the first quantitative demonstration of major losses accompanying changes in drop morphology. 相似文献
Initial experiments have been carried out with drops of aqueous solutions of glucose, sucrose, maltodextrin and coffee extract. The results clearly display the onset of the volatiles-retentive selective diffusion phenomenon. There is also substantial loss of the volatile component later in the drying process, when the drops undergo repeated ex ansion, bursting and cratering due to the formation of internaf bubbles. These experiments appear to be the first quantitative demonstration of major losses accompanying changes in drop morphology. 相似文献
13.
ONACCURACYOFANALYSISOFOFHYDROGEN1前言我公司目前应用的氢气纯度分析方法有两种,一种是爆炸反应法,另一种是焦性没食子酸吸收法。几年来,人们对两种分析方法的准确性曾有过褒贬不一的评论。这里我们也谈谈自己粗浅的观点。2爆炸法测定氢气纯度一定量的氢气样品与适量的空气之均匀混合物因反应后生成液体水而引起气体体积减少,减少的体积等于参加反应气体体积之和。其中l/3为氧气,2/3为氢气。根据氢气取样量和反应前后混气体体积之差,以及氢气在反应中的体积比例关系,可计算出样品的氢气纯度。计算公式式中:A一混… 相似文献
14.
ANALYSIS OF RECENT MEASUREMENTS OF THE VISCOSITY OF GLASSES 总被引:5,自引:0,他引:5
Viscosity of Simple Soda-Silicate 500° to 1400°C Comparison of the results given by English with those of Washburn, Shelton and Libman, indicates a discrepancy in the absolute values of log10 viscosity amounting to 0.6, those of Washburn et al., being relatively too high. If correction for this is made, the isothermal curves of log10 viscosity as a function of soda content are smooth up to 50% Na2O, showing no inflection. The observations as a function of temperature T are all represented within accidental error by an equation of the type where all three constants vary regularly with the composition. Change of Viscosity of Glass (6SiO2, 2Na2O) due to Molecular Substitution of CaO, MgO and Al2O3 for Na2O The effect is clearly brought out by plotting (from the results of English) the change of log10η due to the substitution as a function of temperature. The curves each show a sharp bend at a temperature between 840° and 1050°C, which is designated the aggregation temperature Ta. If we divide these curves by the corresponding percentage substituted, we get curves for each oxide which are straight and parallel below the aggregation temperatures, the slopes (increase of change of log10η per 100°C) being −0.056 (CaO), −0.055 (MgO), −0.018 (A12O3) per per cent oxide substituted. For substitution of 1/2 molecule the slopes are −0.325 (CaO), −0.23 (MgO) and −0.18 (Al2O3) per 100°. At the aggregation temperature the change of log10η per per cent is a minimum, 0.03 to 0.06 for CaO, 0.12 for MgO, 0.07 for Al2O3. Evidence of Aggregation in Glasses, from viscosity Measurements The sharp bends in the plots of change of log10η due to substitution of an oxide for Na2O, suggest the beginning of molecular aggregation at these temperatures. These aggregation temperatures are close to the devitrification temperatures, but the effect on the viscosity curves cannot be due to actual devitrification since it does not change with time. Taking the aggregation temperatures as equal to devitrification temperatures, additional isotherms are roughly sketched into the equilibrium triangle of the system Na2O-CaO-SiO2. Change of Viscosity of Glass (4SiO2, 2Na2O) due to of Substitution of B2O3 for SiO2 The change of log10η (from the results of English) is plotted as a function of temperature, and also the change of log10η per per cent B2O3. The curves are more complex than for the substitution for Na2O. 相似文献
15.
16.
面对日益激烈的市场竞争,摩托车油箱外观质量越来越成为影响销售的因素之一。文章介绍了改进工艺后的油箱涂装,该涂装体系提高了油箱外观的丰满度,降低了油箱涂装的生产成本。 相似文献
17.
18.
A model is developed for the sedimentation from a suspension of two particle species of unequal densities and of different sizes. The composition and the thickness of various layers in the sediments are predicted using graphical and analytical methods. The model predictions were in excellent agreement with experimental results, when the particle size ratio was ≥ 108. When size ratio of the particles was 2.60 and 4.31 the agreement occurred in about 50 percent of the cases. 相似文献
19.
用两个形状指数表征粉煤灰颗粒形貌的研究 总被引:5,自引:0,他引:5
引用两个形状指数表征颗粒形状的概念,即先将颗粒形状近似为椭圆,再将椭圆图像分离:以圆为基准的颗粒宏观形状指数δ;以光滑椭圆为基准的颗粒轮廓凹凸度,即微观形状指数ζ。分析和发展了近似椭圆模型。并运用图像分析仪对粉煤灰、水泥样品进行实验。结果表明,粉煤灰颗粒的两个形状指数δ和ζ都大于水泥颗粒。证明粉煤灰颗粒的球形度、表面光滑度优于水泥,而且,随着粒径增大,δ和ζ呈下降趋势,表明磨制颗粒越粗。(?)粒形状越不规则。文中还运用近似椭圆模型再现了颗粒的模拟图像。 相似文献
20.
本文以三种典型煤的碳燃烧为研究对象,分别采用简单一维沉降燃烧方式和等温加热燃烧方式,实验研究了煤在快速加热条件下,其碳的初期和中,后期燃烧过程。以实验为基础,建立了煤的碳燃烧模型,变工况数值模拟了煤的碳燃烧过程,揭示了煤不同条件下的单颗粒碳燃烧特性。 相似文献