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两种纯度的氯化铵试剂所配制的缓冲溶液对挥发酚 4 - AAP萃取比色法测定结果的影响实验表明 :氯化铵试剂的纯度对挥发酚的测定结果存在较大的影响 相似文献
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The aim of the present work was to produce a polyaluminium ferric silicate chloride (PAFSiC) coagulant from acidic and alkaline
wastewater of purifying graphite by roasting, and subsequently to evaluate coagulation efficiency of the reagent by treating surface
water from the Yellow River as well as municipal wastewater in comparison with the conventional coagulant polyaluminium chloride
(PAC). The PAFSiC coagulant was prepared by co-polymerization. The effects of (Al+Fe)/Si molar ratio, OH/(Al+Fe) molar ratio (i.e.,
value), coagulant dosage and pH value of test suspension on the coagulation behavior of FAFSiC and the stability of the PAFSiC were
also examined. Results showed that PAFSiC performed more efficiently than PAC in removing turbidity, chemical oxygen demand
(COD), and total phosphate (TP). The PAFSiC with a
value of 2.0 and (Al+Fe)/Si ratio of 5 (PAFSiC 2.0/5) showed excellent
coagulation effect for both turbidity and COD, while PAFSiC 1.0/5 was the best for TP. The optimum coagulation pH range of PAFSiC
2.0/5 was 5.0–9.0, slightly wider than that of PAC (6.0–8.0). The process can be easily incorporated into high-purity graphite production
plants, thereby reducing wastewater pollution and producing a valuable coagulant. 相似文献
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光谱纯度是积分路径差分吸收激光雷达最重要的系统参数之一,光谱纯度直接影响CO2数据的探测精度.在模式研究中要求输入观测的CO2数据误差小于1×10-6,对激光器光谱纯度参数设计提出很高要求.本文采用有效吸收截面分析探测反演误差的方法,研究了由光谱纯度带来的CO2柱浓度探测误差,并基于窄带滤波器对光谱不纯能量的抑制作用,对不同带宽的窄带滤波器进行选择和分析,从而达到降低对光谱纯度的要求,提升探测精度的目的,最后讨论了由于窄带滤波器造成的能量衰减所对随机误差的影响.结果表明:当光谱纯度为99.9%,窄带滤波器带宽1GHz,透射率为0.86,脉冲能量为100mJ时CO2探测的系统误差小于0.084×10-6,随机误差小于0.02×10-6,满足探测精度要求. 相似文献
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pH和发酵时间对厨余垃圾发酵产乳酸及光学特性的影响 总被引:1,自引:0,他引:1
通过间歇实验探讨了在中温、非灭菌条件下,pH和发酵时间对厨余垃圾发酵产乳酸及其光学特性的影响.结果表明,采用非灭菌的厨余垃圾发酵产乳酸,发酵液中还原糖浓度低,pH调节到近中性和偏碱性(pH为6~8)的各组还原糖浓度高于偏酸性组(pH=5和pH=4的对照组);在控制pH为7时,总乳酸产生速率达到0.59 g·(L·h)-1,单位挥发性固体的乳酸产量达到0.62 g·g-1;控制pH为7和8时,以有机碳表示的乳酸分别占发酵液总有机碳的78%和89%;控制pH为8时,L-乳酸是主要的异构体形式,单位挥发性固体L-乳酸产量达到0.48 g·g-1;响应面分析结果表明,发酵时间在120 h前,随着pH升高和发酵时间的延长,发酵液中L-乳酸浓度增大,120 h后则下降;pH和发酵时间对L-乳酸占总乳酸的比例有明显影响:偏酸性条件(未调pH及pH=5),发酵前120 h,该比例随发酵时间逐渐增大,L-乳酸在总乳酸中的比例达到0.9,其后,则逐渐下降;偏碱性条件下(pH=8),L-乳酸在总乳酸中的比例在整个发酵时间段内都保持在0.86以上,在发酵时间48 h时达到0.93,而在pH中性条件下,该比例在发酵后期显著下降;控制pH为8时,可以同时获得高的乳酸产量和光学纯度. 相似文献
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A cleaner two-step synthesis of high purity diallyldimethylammonium chloride monomers for flocculant preparation 总被引:4,自引:0,他引:4
In order to improve the flocculation efficiency of polydiallyldimethylammonium chloride(PDADMAC), high molecular weight PDADMAC should be prepared from high purity diallyldimethylammonium chloride(DADMAC) monomers. In this paper, a cleaner method with microwave irradiation and alkali solidification was proposed for preparing high pure DADMAC by selective heating under low temperature, and the prepared high purity DADMAC is characterized using FTIR and atomic absorption spectrometry. The new method provides a solution to the key technical problem of PDADMAC synthesis. Comparing with the conventional methods, the results showed that the advantages of the novel synthesis include: (a) high purity DADMAC is improved from 57% to 71% ; (b) reaction time of tertiary amine preparation is shortened from 6 h to 7 min; (c) water instead of acetone was used as reaction medium; (d) toxic by-products, wastewater and waste gas are eliminated. Flocculant made from the synthesized high purity DADMAC monomers was proved more efficient in flocculation tests. 相似文献
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氯化铵纯度对挥发酚4-AAP萃取比色法测定结果的影响 总被引:1,自引:0,他引:1
两种纯度的氯化铵试剂所配制的缓冲溶液对挥发酚4-AAP萃取比色法测定结果的影响实验表明:氯化铵试剂的纯度对挥发酚的测定结果存在较大的影响。 相似文献