Hydrothermal synthesis of flaky crystallized La2Ti2O7 for producing hydrogen from photocatalytic water splitting

Flaky monoclinic La₂Ti₂O₇ was prepared via a hydrothermal method based on the reaction of Ti(SO₄)₂ and La(NO₃)₃. Relative to the solid-state reaction sample, the flaky La₂Ti₂O₇ showed higher surface areas, much smaller crystal size and more efficient light absorption. All these factors led to the higher photoactivity to produce H₂ from water splitting under UV irradiation.     

Antimony Solubility and Speciation in Aqueous Sulphuric Acid Solutions at 298 K

This work is an experimental and theoretical study of antimony speciation and the solubility of Sb₂O₅, Sb₂O₃ and Sb₂(SO₄)₃ at 298 K in aqueous sulphuric acid solutions (0 to 6 kmol/m³). A thermodynamic model was developed to quantify the solubility products and aqueous metal speciation. Main dissolved species were H₃SbO_3(aq) and H₃SbO_4(aq). The solubility of antimony increases with increasing solution acidity and with the presence of hydrogen peroxide in the solution. The following standard equilibrium constants at 298 K were obtained: Log K⁰_(Sb2O5) = 11.7±0.5, Log K⁰_(Sb2O3) = 32±1, and Log K⁰_(Sb2(SO4)3) = 55±2.     

含氨废水处理技术及工艺设计方案

本文根据氮肥厂废水的特点，研究了高浓度氨氮废水的处理方法-吹脱法的除氨机理和氨氮去除率的影响因素。针对pH值和温度对氨氮去除率的影响，我们做了实验，结果表明若去除率要达到90％以上，pH值必须大于12且温度高于90C。同时可以用CaO将废水的pH值调节到12以上。最后，针对这种废水的处理设计了可行的工艺方案。     

Margarines: A rheological study

Time-dependent flow properties of both commercial and pilot plant-made margarines were characterized under steady shear. Flow curves were fitted to the kinetic expression τ = τ _i +a e ^−k1t +b e ^−k2t . A first-order kinetic model did not describe the observed destruction process of the margarine structure in an adequate manner. In the proposed model, two structures with different destruction rates are postulated. Each structure contributes to a part of the shear stress necessary to deform the margarine sample. The parameters τ _i a andb are temperature-dependent. Decreasing temperatures produce an exponential increase of τ _i , a linear increase ofb and an increase ofa up to a point beyond which it remains constant. A physical interpretation of the model is proposed. The role of the aqueous phase was also studied. Greater hardness was detected at higher water content. Parameter τ _i increased, at any selected temperature, with increasing aqueous phase content of the sample. Parametera increased with decreasing temperatures and higher water content. On the other hand, parameterb was not affected by the amount of aqueous phase. This kinetic model could be employed to perform studies on the influence of different parameters of margarine formulation on its rheologic behavior.     

Lipase-catalyzed transesterification of phosphatidylcholine at controlled water activity

The incorporation of a free fatty acid into thesn-1 position of phosphatidylcholine by lipase-catalyzed transesterification was investigated. The thermodynamic water activity of both the enzyme preparation and the substrate solution was adjusted to the same value prior to the reaction. The reaction rate increased with increasing water activity but the yield of modified phosphatidylcholine decreased due to hydrolysis. By using a large excess of the free fatty acid (heptadecanoic acid), the hydrolysis reaction was slowed down, so a higher yield was obtained at a given degree of incorporation. The best results were obtained withRhizopus arrhizus lipase immobilized by adsorption on a polypropylene support. With this preparation, a yield of 60% and nearly 50% incorporation of heptadecanoic acid (100% incorporation in thesn-1 position) was obtained at a water activity of 0.064. The enzyme preparation had good operational stability and position specificity. Little incorporation (<1%) was observed in thesn-2 position, when almost all the fatty acid in thesn-1 position was exchanged.     

Fischer–Tropsch synthesis: Deactivation of promoted and unpromoted cobalt–alumina catalysts

The loss in activity of Pt-promoted and unpromoted 25 wt% Co–Al₂O₃ catalysts has been compared under identical conditions except for adjustment of the space velocity to give the same initial CO-conversion. Both catalysts underwent a 200 h period of rapid, initial decline in CO conversion and then a slower, linear decline during the next 1000 h. Pt-promotion did not alter the cobalt dispersion (or average particle size) from that of the unpromoted catalyst but did increase the amount of cobalt that was reduced. When compared not by time-on-stream, but by the moles of Co converted per unit weight of catalyst, both the Pt-promoted and unpromoted catalysts decline in activity at the same rate.     

阳光下TiO2/GAC光催化处理洗涤剂废水的研究

利用太阳光作光源，采用固定在颗粒活性炭中的TiO2(TiO2／GAC)作光催化剂，利用其将活性炭极好的吸附性与TiO2优良的光催化性能结合于一体的特性，设计了对以洗衣粉配置的洗涤剂模拟废水的两种处理方案：同时光照-吸附法和吸附饱和-光照水洗再生法，并在实验基础上对两种方案的一些性能进行了讨论。     

航天推进剂废水超临界水氧化反应法处理研究

采用新兴的绿色坏保技术-超临界水氧化反应法，对含偏二甲肼的航天推进剂废水进行了处理研究。试验结果表明，采用小型的管道式连续SCWO反应系统能够迅速将该类推进剂废水中的毒害成分-偏二甲肼彻底分解为无害的CO2和N2。反应温度和反应停留时间是影响偏二甲肼去除率的主要因素，当反应温度超过500℃，停留时间达到95s时，偏二甲肼的COD去除率大于99．9％，完全达到了国家航天推进剂水污染物排放标准的要求。     

快速高效隔膜压滤机在鹤壁四矿选煤厂的应用

介绍了快速高效隔膜压滤机的主要性能参数和特点 ;分析了压滤机在煤泥水处理系统中的应用情况和运行结果 ;应用快速高效隔膜压滤机对煤泥水处理系统进行改造后获得了较好的经济及社会效益     

产业与部门用水关联及尺度效应分析

以河南省为例,应用基于纵向集成的改进假设抽取法,对该区域三次产业和八大部门的水资源消耗及转移状况进行量化分析,由分析结果可知:农业和基础工业是河南省的主要水资源净输出部门,轻工业、高科技工业和建筑业是主要的净输入部门。河南省用水关联性较强产业部门包括农业-轻工业、农业-高科技工业、基础工业-高科技工业以及农业-基础工业。对不同尺度的用水关联成果进行了分析,分析结果表明:不同分析尺度的纵向集成消耗总量是相等的,且与其直接消耗总量相同;用水关联具有非线性的尺度效应,不能通过线性运算实现不同尺度关联效应的转换;分析尺度越小,分类越细化,内部效应越低,系统中流动转移的水量就越多,反之则相反。研究成果可为区域产业结构调整和水资源管理政策的制定提供参考。