从水溶液中分离回收醋酸方法的评述

评述了从水溶液中分离回收醋酸的普通精馏法、共沸精馏法、酯化法和溶剂萃取法，具体分析了各种方法 特点及适用范围。建议在工业上对较高浓度的醋酸用低沸点溶剂萃取－共沸精馏联合法，对低浓度醋酸溶液采用有机胺溶剂萃取法进行分离。     

河流水质系统的灰色规划方法和应用

借助于河流水质灰色模型,可以对河流水质系统进行灰色规划。灰色规划考虑了实际河流水质系统中客观存在的不确知因素和偶然因素影响,概述了河流水质系统的灰色规划模型的构造、河流水质系统灰色规划模型的求解及其在四川沱江水质系统规划中的应用。     

餐饮业油烟气中醛类化合物的荧光法测定

提出了餐饮业油烟气中醛类化合物的荧光测定方法。通过试验选择丙醇作为油烟气中醛类化合物的吸收剂。研究了Ｈａｎｔｚｓｃｈ反应在测定油烟气中醛类化合物时的反应条件。样品与荧光试剂等体积混合,在ｐＨ６．０的体系中,５７℃下反应１５ｍｉｎ。     

浅谈交际法在高职旅游英语教学中的具体应用

交际法教学是英语教学中一个重要教学理论分支,在指导高职旅游英语教学方面起着积极重要的作用。笔者利用调查、总结归纳等研究方法,分析交际法教学的特点及作用,旨在进一步深化与探索交际法教学在高职旅游英语实际教学中的应用形式,拓展外延,并重点阐述了交际法教学在实际教学应用中的具体方法。     

Effect of composting process on phytotoxicity and speciation of copper, zinc and lead in sewage sludge and swine manure

The concentration and bioavailability of heavy metals in composted organic wastes have negative environmental impacts following land application. Aerobic composting procedures were conducted to investigate the influences of selected parameters on heavy metal speciation and phytotoxicity. Results showed that both of sewage sludge (SSC) and swine manure (SMC) composting systems decreased the pH, the content of organic matter (OM) and dissolved organic carbon (DOC), and total amounts of Cu, Zn and Pb. Sequential extraction showed that readily extractible fractions of exchangeable and carbonate in Cu and Zn increased during SSC composting but decreased during SMC composting, thus their bioavailability factors (BF) enhanced in SSC but declined in SMC. The fraction of reducible iron and manganese (FeMnOX) of Cu and Zn in SSC and FeMnOX-Cu in SMC decreased, but FeMnOX-Zn in SMC gradually increased in the process of compost. In contrast, the changes of Pb distributions were similar in two organic wastes. Pb was preferentially bound to the residual fraction and its BF decreased. The evolution of heavy metal distributions and BF depended on not only total metal concentrations but also the other properties, such as pH, decomposition of OM and decline of DOC. The germination rate (RSG), root growth (RRG) and germination index (GI) of pakchoi (Brassica Chinensis L.) increased during the composting process. Linear regression analysis demonstrated that GI, which could represent phytotoxic behavior to the plants, could be poorly predicted by BF or total amount of metals, i.e., BF-Zn, T-Cu. However, the inclusion of other physicochemical parameters (pH, OM and DOC) could enhance the linear regression significances (R).     

硫酸锰渣污染土壤中重金属的形态分布及生物活性

测定了硫酸锰渣污染土壤中Cu,Zn,Cd,Pb,Mn的总量和各形态含量.结果表明重金属总量远超过环境背景值和土壤环境二级标准.重金属各形态分布特征:Cu,有机态>残渣态>铁锰氧化态>碳酸盐态>可交换态;Zn,残渣态>铁锰氧化态>有机态>碳酸盐态>可交换态;Cd,铁锰氧化态>可交换态>碳酸盐态>残渣态>有机态;Pb,铁锰氧化态>残渣态>有机态>碳酸盐态>可交换态;Mn,铁锰氧化态>残渣态>可交换态>有机态>碳酸盐态.重金属的生物可利用性系数和迁移系数均为Cd>Mn>Pb>Cu>Zn.     

CuO/γ-Al_2O_3负载型催化剂催化燃烧处理油烟

采用等体积漫渍法制备不同CuO负载量的CuO/γ-Al2O3负载型催化剂,用X射线衍射仪、扫描电镜对该催化剂负载层活性组分的表面形态、晶相结构和颗粒大小进行表征,考察了该催化荆催化燃烧处理油烟的催化活性(以油烟净化效率表征).结果显示,催化活性随CuO负载量的增加.反应温度的升高而提高,但随烟气流量的增大而降低;在CuO负载量为20%(质量分数)、反应温度为350℃.烟气流量为5 L/min的最佳实验条件下,CuO/γ-Al2O3负载型催化剂的油烟净化效率最高.可达88.6%.该催化剂对油烟的催化燃烧具有较高的催化活性.     

合成碳羟基磷灰石对水中双酚A的吸附性能研究

利用废弃蛋壳为原料、尿素为添加剂,合成纳米碳羟基磷灰石(CHAP)用于吸附水中双酚A（BPA）。利用红外光谱、扫描电镜和X射线能谱测试技术对CHAP样品表面化学进行了表征,同时考察了环境因子pH值、吸附时间和BPA初始浓度对吸附的影响。实验结果表明,CHAP对BPA去除率在酸性（pH=3～6）溶液中较好,而在中性和碱性环境中减弱。通过静态吸附实验数据计算分析得知,CHAP对BPA吸附符合Langmuir和Freundlich等温式,准二级动力学模型比准一级动力学模型能更好地描述CHAP对BPA吸附动力学行为。     

云阳县生态危机的现状及其对策

为了改善生态环境，发展贫困地区经济，树立人与延期共同，协调发展观念，建立合理的农业结构和作物布局，详述了四川云阳县生态危机的现状和存在问题，提出了保护环境，发展立体农业的合理布局的建议。     

Pedological characteristics of Mn mine tailings and metal accumulation by native plants

In southern China revegetation and ecological restoration of many abandoned Mn tailings has become a major concern. To determine the major constraints for plant establishment and evaluate the feasibility of remediation, a comparative study was conducted on Mn tailings and rhizosphere soils at the boundary of the tailings pond. Both tailings and rhizosphere soils had neutral to slightly alkaline pH and normal electrical conductivity. They were both enriched with organic matter (6.8-9.2%), total N (1.77-5.94 g kg(-1)), available P (41.78-73.83 mg kg(-1)) and K (146.7-906.9 mg kg(-1)), suggesting the tailings were a nutrient rich substrate for revegetation. Mn tailings were clay textured, while rhizosphere soils were silty loam or clay loam. The compaction and anoxic nature of Mn tailings were considered to be the major constraints for plant establishment. Total Mn (31903 mg kg(-1)), Cd (119 mg kg(-1)), Cu (126 mg kg(-1)) and Zn (2490 mg kg(-1)) in tailings were all at phytotoxic levels, but did not differ significantly from those in rhizosphere soils. In both tailings and rhizosphere soils, percentages of water- and DTPA-extractable metals were less than 1% and 2% of the total metal pools, respectively. Sequential extraction revealed that the majority of Mn, Cu and Zn were associated with the residual fraction, while the majority of Cd occurred as Fe-Mn oxides. The natural succession of plants around Mn tailings formed a distinctive metal-tolerant plant community, mainly comprising nine species such as Cynodon dactylon and Humulus scandens and so on. All species studied could be good candidates for revegetation of Mn tailings.