机械能作用下中温快速制备渗钛涂层的研究

将传统的粉末包埋渗和表面纳米化工艺相结合,得到一种中低温快速制备金属涂层的方法,在低温(400～600℃)、短时间(30～120min)下成功制备了一系列金属铝化物涂层.将此方法用于金属表面的渗钛处理,利用两种不同的活化剂NH4F和AlCl3·6H2O Fe2O3,借助介质球的冲击效应,在650℃振动处理180min就可在碳钢表面制备10～15μm厚的渗钛层.SEM和XRD研究结果表明,渗钛层的结构与选用的活化剂种类有关.在HCl质量分数为5%的溶液中进行的极化曲线测试结果显示,用NH4F、AlCl3·6H2O Fe2O3作活化剂,所制备的渗钛层腐蚀速度分别为0.32 mA/cm2、0.07 mA/cm2,相对于碳钢空白样(其腐蚀速度为4.4 mA/cm2),其耐蚀性分别提高了13.75、62.85倍.     

碳酸钾-二乙烯三胺复合溶液吸收烟气中CO2实验研究

热钾碱溶液在工业脱除二氧化碳中已获得较广泛的应用,但存在吸收速率差、再生负荷高等缺点-开发新型热钾碱溶液成为目前研究热点.采用搅拌实验装置,研究碳酸钾溶液及不同配比的碳酸钾-二乙烯三胺(DETA)复合溶液对烟道气中二氧化碳的吸收和解吸性能,揭示了吸收速率、吸收容量和酸碱度与时间之间的内在联系;对CO2初始逸出温度,试液...     

Stepwise superposition approximation approach for analytical solutions with non-zero initial concentration using existing solutions of zero initial concentration in contaminate transport

Analytical solutions for contaminant transport are widely used for both theoretical and practical purposes. However, many existing solutions are obtained subject to an initial condition of zero concentration, which is often unrealistic in many practical cases. This article proposed a stepwise superposition approximation approach to solve the non-zero initial concentration problem for first-type and third-type boundary conditions by using the existing zero initial concentration solution. Theoretical examples showed that the approach was highly efficient if a proper superposition scheme with relative concentration increments was constructed. The key parameter that controlled the convergence speed was the time increment (Δt) multiplied by the rate constant ( ). The approach served also as an alternative way to make a convenient concentration calculation even if the non-zero initial concentration solution of a problem was known.     

Removal of trace arsenic（V） and phosphate from water by a highly selective ligand exchange adsorbent

The ligand exchange adsorbent could be used to remove the toxic arsenic(V) and phosphate efficiently from water even in the presence of foreign anions and possible to apply in chemical industry.     

Characteristics and aluminum reuse of textile sludge incineration residues after acidification

Leaching solution of sludge incineration residue demonstrated a good pollutant removal efficiency for textile wastewater and can be reused as a textile wastewater treatment agent for pre- and post-processing.     

高分子固体废物基活性炭对有机染料的吸附解吸行为研究

分别以3种高分子固体废物,即轮胎橡胶、聚氯乙烯(PVC)和聚对苯二甲酸乙二酯(PET)为原料,利用KOH活化法制备高比表面积活性炭.通过吸附实验研究了活性炭对2种有机染料(亚甲基蓝和甲基橙)的吸附、解吸行为,同时探讨了溶液pH值、离子强度和表面活性剂对吸附的影响.结果表明,PVC和PET基活性炭比表面积分别为2 666和2 831 m2.g-1,中孔容积分别为1.06和1.30 cm3.g-1,15 min内对亚甲基蓝和甲基橙的去除率分别高达98.5%和97.0%、99.5%和95.0%,且Langmuir模型拟合的染料最大吸附量均超过2 mmol.g-1,显著高于商业活性炭F400.Langmuir模型比Freundlich模型能更好地描述2种染料的吸附行为,说明吸附以表面单层覆盖为主.溶液pH值、离子强度和表面活性剂对染料吸附均有较大影响.制备的高分子基活性炭对亚甲基蓝的吸附强于甲基橙,2种染料均不容易发生解吸.实验结果可为高分子固体废物的资源化利用、制备经济高效的碳质吸附材料提供科学依据.     

油页岩灰渣浸取铝酸钠溶液试验研究

以油页岩废渣为原料,通过酸浸法浸取油页岩灰渣中的铝酸钠溶液。采用焙烧活化方法将废渣中含铝的低活性晶体物质活化为高活性半晶体或非晶体物质,利用酸浸法浸取焙烧后的高活性含铝废渣,得到铝液;依据试验分析了影响酸浸法浸取铝酸钠溶液的主要影响因素为焙烧温度、焙烧时间、浸取酸浓度和浸取温度;得出酸浸法的最佳工艺参数：活化温度850℃,活化时间3h,选用酸浓度40％,浸取温度60℃,此时油页岩废渣铝浸取率为75％。     

Factors effecting aluminum speciation in drinking water by laboratory research

Effects of aluminum on water distribution system and human health mainly attribute to its speciation in drinking water. Laboratory experiments were performed to investigate factors that may influence aluminum speciation in water supply system. The concentration of soluble aluminum and its transformation among other aluminum species were mainly controlled by kinetics processes of related reactions. Total aluminum concentration had a notable e ect on the concentrations of mononuclear and soluble aluminum in the first 4 day; then its e ect became weak. At pH above 7.50, both fluoride and orthophosphate had little e ect on aluminum speciation; while, when the solution pH was below 7.50, the concentrations of mononuclear and soluble aluminum were proportional to the concentration of fluoride and inversely proportional to the concentration of orthophosphate. Both mononuclear and polynuclear silicic acids could complex with mononuclear aluminum by forming soluble aluminosilicates. In addition, the adding sequence of orthophosphate and aluminum into drinking water would also a ect the distribution of aluminum species in the first 4 day. In order to minimize aluminum bioavailability in drinking water, it was suggested that orthophosphate should be added prior to coagulant process, and that the concentrations of fluoride and silicic acids should be controlled below 2.0 and 25 mg/L, respectively, prior to the treatment. The solution pH in coagulation and filtration processes should be controlled in the range of 6.50–7.50.     

可吸入性超细石英粉尘在模拟人体体液中溶解特性

为研究石英颗粒被吸入人体后在体内的溶解行为,以Gamble溶液模拟人体体液环境,研究了粒径中值d50为2.8μm的石英粉尘在3个酸度的Gamble溶液中溶解特性.结果表明,石英颗粒中Si的溶出量随溶解时间的延长,不断增大,但在较强的酸性环境下,存在一定程度的溶解抑制.SEM观察发现,超细石英颗粒在Gamble溶液中表面被溶蚀,表面和边壁均出现了不同程度的凹蚀、脱皮现象,但颗粒内部溶蚀现象不明显.FTIR结果表明,超细石英颗粒表面经Gamble溶液溶蚀后其Si-O-Si反对称伸缩振动发生一定程度的改变.XRD物相表征显示超细石英颗粒溶蚀前后物相特征无明显变化,但Rietveld结构精修结果表明溶解后超细石英颗粒晶胞参数和晶胞体积均有压缩,可见颗粒表面硅可能由结晶的有序结构转化为无定形结构,后溶解于体液中.超细石英颗粒在模拟人体体液中溶蚀现象显著,但未引起整个颗粒晶体结构的崩塌,颗粒表面溶解于体液中,引起pH值增大并趋于稳定于偏碱性环境,可吸入性超细石英颗粒溶蚀后暴露出的新鲜表面以及溶解于体液中的硅对人体健康造成潜在的严重威胁.     

在废弃的高压气瓶中自制氢气时爆炸的主要原因是什么

<正>主持人,你好:20年前,我单位的两位职工为了搞活动想自己制作氢气球,他们找了一个废弃的高压气瓶,放入了很多踩扁的铝制易拉罐,而后放入烧碱溶液。气瓶内发生反应后瓶身发热,两位制作人员就将气瓶抬到了不远处的一个水坑内,用水浸了一会儿后抬上岸。又过了一段时间,气瓶爆炸,两位当事人一死一伤。请问,发生爆炸的主要原因是什么?两位制作人员用水浸降温气瓶的做