脱硫石膏-秸秆新型复合墙体材料性能的研究

介绍了一种新开发的轻质墙体材料.这种墙体材料由脱硫石膏和秸秆按一定比例组合并掺入适量外加剂加水拌合而成.其质量轻(干密度仅为720 kg/m3),有足够的强度(1～3 d强度大于10 MPa,14 d强度大于20 MPa),耐久性好.脱硫石膏-秸秆复合料处于碱性环境下(浆液pH值=11),秸秆不易腐蚀,潮湿环境下也有较好的耐久性.由于脱硫石膏是电厂烟气脱硫的副产品,秸秆是收获果实后的废弃物,因此,新开发墙体材料的推广应用极有助于减轻或避免烟气中SO2和秸秆燃烧烟尘对大气的污染,以及对其它方面造成的损害.     

低酸性酚醛泡沫制备工艺研究

采用提高发泡温度、降低酸用量的方法,制备出低酸性酚醛泡沫.实验结果表明,在发泡温度为90℃,吐温-80用量为5％、石油醚用量为5％、固化剂用量为6％的条件下,制得的酚醛泡沫其性能与常规发泡工艺的相近,泡沫闭孔率大于80％,pH值大于4.     

沥青混合料对水环境的影响

为了研究与沥青混合料接触后水质的变化,首先在实验室内成型了10组沥青混合料的马歇尔试件,成型试件时考虑了不同的沥青混合料级配、空隙率和沥青标号,以及添加抗剥落剂等因素,并把试件放入不同pH值的水样中真空饱水24 h;然后按照中国生活饮用水评价指标,测试了真空饱水后水样的pH值、耗氧量、总硬度及重金属含量.结果表明:沥青混合料真空饱水24h后,水质恶化明显,中性水样pH值约增大0.4倍,酸性水样pH值则增大1.7倍以上,在沥青混合料中添加抗剥落剂以及降低沥青混合料的空隙率可以有效降低水样pH值的增大幅度;水样的化学耗氧量增大3～4倍,通过降低沥青混合料空隙率、适当提高初始水样的pH值至中性等方式,可以降低水样中有机物的含量;水样的总硬度增大3～4倍,在沥青混合料中添加抗剥落剂可降低水样总硬度的增大幅度.     

Hydrogen and methane production from household solid waste in the two-stage fermentation process

A two-stage process combined hydrogen and methane production from household solid waste was demonstrated working successfully. The yield of 43 mL H(2)/g volatile solid (VS) added was generated in the first hydrogen production stage and the methane production in the second stage was 500 mL CH(4)/g VS added. This figure was 21% higher than the methane yield from the one-stage process, which was run as control. Sparging of the hydrogen reactor with methane gas resulted in doubling of the hydrogen production. pH was observed as a key factor affecting fermentation pathway in hydrogen production stage. The optimum pH range for hydrogen production in this system was in the range from 5 to 5.5. The short hydraulic retention time (2 days) applied in the first stage was enough to separate acidogenesis from methanogenesis. No additional control for preventing methanogenesis in the first stage was necessary. Furthermore, this study also provided direct evidence in the dynamic fermentation process that, hydrogen production increase was reflected by acetate to butyrate ratio increase in liquid phase.     

SBR法短程硝化及过程控制研究

考察了采用SBR法处理氨氮浓度较高的化工废水时供氧方式对硝化过程中DO、ORP和pH值变化规律的影响。试验结果表明，在曝气量恒定的条件下，可以硝化过程中DO和pH值升高速率的不同表征反应的进程程序，即当氨氮浓度接近零时，DO和pH值升高速率或变化幅度加大，二者可以作为SBR硝化反应时间的控制参数，而ORP值对SBR硝化反应结束的批示作用不是很明显；在DO量恒定的情况下，pH值在整个硝化反应过程中都是缓慢下降或趋于稳定的，当硝化反应结束时突然升高，因此pH值也可作为SBR硝化反应时间较好的控制参数，而ORP值在硝化反应的初期快速升高，之后升高的速度越来越慢直至趋于平稳，它对SBR硝化反应结束的指标作用同样不是很明显。     

pH值对BiOIO_3结构及其光催化性能影响研究

采用水热合成法通过调控反应前驱液pH值制备出具有不同形貌结构的碘酸氧铋(BiOIO_3)光催化剂。采用X射线衍射仪(XRD)、扫描电子显微镜(SEM)和紫外-可见吸收光谱(UV-vis)等测试方法对合成的样品进行物相、形貌及光学性能表征。以罗丹明B和2,4-二氯苯酚的降解效率来评价在不同合成条件下所制备BiOIO_3的光催化活性。结果表明,反应前驱液的pH值影响所合成BiOIO_3的形貌结构及光催化性能,只有反应液的pH值在酸性条件下,所得产物为纯的BiOIO_3。在pH值为2～3的酸性范围内所制备的BiOIO_3纳米片具有优异的光催化活性,光辐射15 min时,罗丹明B的降解效率可达95%,光生空穴是主要的氧化活性基团。     

TiB2粉末化学镀银工艺研究

采用化学镀银法制备Ag/TiB2复合粉末,系统研究NaOH,HCHO,NH.3H2O的加入量及反应时间等参数对包覆粉末质量的影响及TiB2表面改性对AgTiB2材料性能的影响。结果表明:NaOH和HCHO含量的增加可促进Ag的还原反应;pH值的大小对Ag的还原有显著的影响,pH值大可加快反应过程,使Ag的还原更加彻底;NH3.H2O在化学镀银过程中起稳定作用,随着NH3.H2O的增加,使反应液更为稳定,Ag不易发生自分解,但也导致镀银溶液中主盐的Ag不容易被还原,不能获得Ag均匀包覆的TiB2复合粉末;反应时间的延长对于反应后粉末中Ag含量的增加影响并不十分明显。采用化学镀的粉末所制备的Ag/TiB2复合材料的致密度、硬度和电导率分别提高了4.59%,12.20%和7.91%。     

溶液pH值对不同粒径蛭石吸附Cu2+、Pb2+的影响

研究了蛭石对重金属离子的吸附,并初步探讨了不同粒径的蛭石吸附Cu2 、Pb2 的pH值影响范围。结果表明:pH值是影响蛭石吸附重金属离子的一个重要因素,且蛭石的粒径越小,其pH值的影响范围越大,对于Cu2 的吸附效果明显高于Pb2 。     

金回收率的主要影响因素分析

通过试验研究，找出了狮子山矿矿石中伴生金回收率的主要影响因素，进而有针对性地采取提高磨矿细度、适当降低并严格控制矿浆ｐＨ值，用对金捕收能力强的丁铵黑药药剂和闪速浮选工艺，使伴生金的回收率得以提高。     

Role of activated carbon on micropollutans degradation by ionizing radiation

The objective of this study was to analyze the influence of the presence of activated carbon on the degradation of the triiodinated contrast medium diatrizoate (DTZ) by the simultaneous use of gamma radiation and activated carbon. Four commercial activated carbons (Ceca, Witco, Sorbo, and Merck) with different textural and chemical characteristics were used for this purpose. The percentage DTZ removal obtained was considerably higher with the gamma radiation/activated carbon (GM/AC) system than with radiolysis in the absence of activated carbon, and it depended on the specific activated carbon employed. First, we optimized the amount of activated carbon required to maximize the amount of DTZ removed by the GM/AC system (0.06 g). The degradation constants were higher with the GM/AC system than with radiolysis alone, evidencing a synergic effect that favors pollutant removal. This synergic effect is independent of the textural but not the chemical characteristics of the activated carbon, observing a higher synergic activity for carbons with a higher surface content of oxygen, specifically quinone groups. We also highlight that the synergic effect of the activated carbon requires adsorbent–adsorbate electrostatic interaction and is absent when this interaction is hindered.