土壤中铝的溶出及形态研究

用连续提取法研究１ｍｏｌ／ＬＫｃｌ,１ｍｏｌ／ＬＮＨ４Ａｃ,１ｍｏｌ／ＬＨｃｌ和０．５ｍｏｌ／ＬＮａＯＨ４种化学浸提液对土壤中铝的溶出,溶出名中用羊毛羊花菁Ｒ比色法测定。结果表明,铝的溶出量与与土壤类型、总铝、有机质含量等因素有关。１ｍｏｌ／ＬＫｃｌ浸提液对酸性土能溶出一定量的变换态铝,而对非酸性土则不能溶出或铝溶出量极微。０．５ｍｏｌ／ＬＮａＯＨ浸提出的铝量与总铝量之间有显著相关性。     

抛石环境中铝合金阳极性能评价及其对海底隧道钢壳保护效果评估

目的 解决埋覆介质中牺牲阳极电化学性能评价的不确定性,实现非匀质介质中牺牲阳极电容量测试结果的评价和对比.方法 模拟沉管隧道埋覆的环境介质,对铝合金牺牲阳极的电容量和溶解形貌进行评测.为区别于现有的海水等匀质介质中阳极的检测方法,建立非匀质介质中铝阳极电化学性能评价方法.另外,在上述埋覆介质中,测定阳极和阴极的极化曲线,修正仿真计算的边界条件,有利于模拟这种高电阻率介质环境下阴极保护电位分布.结果 测试箱所测电阻率与商用便携式电导率仪测定精度相当.A1阳极在低电阻率的海水中(25～40?·cm)性能稳定,电容量稳定在2500 A·h/kg,溶解性能良好;在40?·cm海淡水+回填石的混合介质中,电容量测试值数据波动大,重现性差.B1阳极在海水(25～40?·cm)中的电容量和A1阳极相当,未见到差异,在40?·cm海淡水+回填石混合介质中,电容量数值分散性小,电化学活性高.结论 混合介质中的评价试验体现了海淡水、混合介质电阻率和回填石对阳极溶解产物阻滞的综合效应,提高了抛石环境中铝阳极寿命评估的准确性,尤其适用于沉管隧道钢壳用铝合金阳极电化学性能评价和牺牲阳极保护效果评估.     

含铬钻井泥浆固化及影响因素

固化技术是含铬钻井泥浆无害化处理最有效的方法。以四川西部某钻井泥浆为研究对象,选取水泥、石灰、聚铝和水玻璃作为固化处理剂,运用正交试验研究了含铬钻井泥浆实验条件。最佳试验配方是：先将泥浆含水率调整为46%,水泥、聚铝、石灰和水玻璃的添加量分别为10%、1%、3%和0.5%。固化72 h,该试验配方对六价铬和总铬的固化率分别达到93%和95%,浸出六价铬浓度符合地下水三类水标准(GB/T14848-9),浸出总铬浓度符合国家污水综合排放标准（GB5085.3-1996）。     

Comparison of sediment metal:aluminum relationships between the eastern and gulf coasts of the United States

Aluminum is often used as a conservative tracer toseparate natural from anthropogenic components ofmetal contamination in marine sediments, butidentifying uncontaminated sites to develop baselinemetal:aluminum relationships can be problematic inpopulated areas. Here we present a new method foridentifying baseline relationships in high populationdensity areas. The method involves comparing theresidual from the metal:aluminum regression with anindependent estimate of laboratory measurement error,based on the premise that mean square error from theregression must equal laboratory measurement error forany data set that is free of anthropogenicallyenriched sites. The method is applied to data setsfrom the mid-Atlantic and Gulf coasts of the UnitedStates to test consistency in baseline relationshipsbetween these two coasts of geologically differentorigin. Differences in metal:aluminum relationshipsbetween coasts were found to be small and limited tothe least abundant trace metals.     

Adsorption behavior of condensed phosphate on aluminum hydroxide

Sodium pyrophosphate （pyro-P, Na4P2OT）, sodium tripolyphosphate （tripoly-P, Na3P3O10）, and sodium hexametaphosphate （meta-P, （NaPO3）6） were selected as the model compounds of condensed phosphate to investigate the adsorption behavior of condensed phosphate on aluminum hydroxide. The adsorption was found to be endothermic and divisible into two stages： （1） fast adsorption within 1 h; and （2） slow adsorption between 1 and 24 h. The modified Freundlich model simulated the fast adsorption stage well; the slow adsorption stage was described well by the first-order kinetics. The activation energies of pyro-P, tripoly-P, and meta-P adsorption on aluminum hydroxide were determined to be 20.2, 22.8 and 10.9 kJ/mol P adsorbed, respectively, in the fast adsorption stage and to be 66.3, 53.5 and 72.5 kJ/mol P adsorbed, respectively, in the slow adsorption stage. The adsorption increased the negative charge of the aluminum hydroxide surface. Transmission electron microscopy and energy dispersive X-ray analysis analyses provided evidence that the adsorption was not uniform on the surface and that the small crystals contributed more to the fast adsorption than the normal sites did. The results from X-ray fluorescence spectrometry and X-ray photoelectron spectroscopy tests also revealed the uneven adsorption of condensed phosphate as a function of the penetration depth. More condensed phosphates were adsorbed on the outer surface of aluminum hydroxide than in its inner parts.     

Treatment of tannery wastewater by electrocoagulation

Treatment of tannery wastewater by electrocoagulation with low cell current(≤1A)and soluble electrodes(mild steel electrodes and aluminum electrodes)was studied.Compared with aluminum electrodes,mild steel electrodes were more effective for the removal of sulfide,with a removal efficiency of over 90%.But during the treatment process,black color precipitate typical to iron(Ⅱ)sulfides was produced.While aluminum electrodes were effective to eliminate the colority of the effluent,the removal efficiency of sulfide was lower than 12%.The mechanisms of the removal of chemical oxygen demand,ammonia,total organic carbon,sulfide and colority with the two soluble electrodes(mild steel and aluminum electrodes)were discussed in detail.In order to exert the predominance of diffenent types of electrodes,the tannery wastewater was treated using mild steel electrodes first followed by the filter and finally by the aluminum electrodes,the elimination rates of chemical oxygen demand,ammonia,total organic carbon,sulfide and colority were 68.0%,43.1%,55.1%,96.7% and 84.3%,respectively,with the initial concentrations 2413.1 mg/L,223.4 mg/L,1000.4 mg/L,112.3 mg/L and 256 dilution times,respectively.The absorbance spectra and energy consumption during electrocoagulation process were also discussed.     

不同粒度铝粉在水平管道内的爆炸压力测定

利用自制的水平管道式气体-粉尘爆炸试验装置对不同粒度铝粉的爆炸压力进行测试。结果表明,爆炸压力及爆炸压力上升速率都随着铝粉粒度的减小而增大,粒度为6～8μm,9～12μm,15～17μm铝粉的平均最大爆炸压力分别为0.63 MPa,0.56 MPa,0.45 MPa,爆炸压力上升速率分别为47.2MPa/s,38.1MPa/s,30.2MPa/s。铝粉粒度越小,在相同时刻铝粉参与反应的时间越提前。在水平管道内,测试结果受点火延迟时间及测试装置尺寸的影响较大。     

聚合硫酸铁铝硅的制备及混凝性能

研究了以硫铁矿烧渣、硫酸、铝酸钙粉和水玻璃为原料制备新型无机高分子复合混凝剂聚合硫酸铁铝硅（PFASS）的方法,采用微电泳技术研究了不同n（SiO2）：n（Fe）的PFASS的水解聚合产物的电动特性,应用超滤法对PFASS、聚合硫酸铁铝（PFAS）和聚合硫酸铁（PFS）的表观相对分子质量了进行测定,并对PFASS混凝性能及其混凝机理进行了研究。研究结果表明,在对高岭土悬浊液的混凝处理中,PFASS比PFAS和PFS具有更优的去浊性能。     

聚合硅酸氯化铝铁的制备及其絮凝性能

利用盐酸酸洗废液制备聚合硅酸氯化铝铁（PSAFC）,并用PSAFC处理造纸脱墨废水,考察了各种因素对絮凝效果的影响。实验结果表明：在废水pH为6、PSAFC加入量为240mg／L、搅拌转速为150r／min、搅拌时间为2min,静置时间为25min的条件下,COD、浊度、色度的去除率分别为87．2％,99．2％,94．5％;PSAFC的絮凝效果明显好于市售的聚合氯化铝和聚合氯化铁.     

凝胶层析-荧光分光光度法联用分析饮用水中铝的形态

将凝胶层析与荧光分光光度法相结合进行饮用水中铝形态的分析.结果表明,凝胶层析对胶体态铝和溶解态铝有较好的分离效果.依据衍生试剂8-羟基喹啉(8-HQ)和铬蓝黑R(EBBR)与不同铝形态结合强度的差异,通过荧光分光光度法可分析饮用水中的单核铝、无机单核铝,再结合硝酸消解可测定饮用水中的总铝、溶胶态铝和胶体态铝.对饮用水中铝形态的分析表明:清华大学地区的地下水和北京市给水管网末端水的总铝含量均在50μg·l-1以下,无机单核铝为饮用水中铝的主要存在形态.