粉煤灰水热法合成沸石及其对氨氮吸附性能的研究

以粉煤灰为原料,采用NaOH碱熔融制得粉煤灰熟料,由水热法合成沸石产品。通过单因素试验和正交试验考察搅拌陈化时间、水热晶化时间、液固比对合成沸石的氨氮吸附容量的影响。试验结果表明:搅拌陈化时间为12 h、水热晶化时间为6 h、液固比为10时,合成的产品主要为P型沸石,其氨氮吸附容量达最大为6.15 mg/g,并以此为理论基础讨论其运用于水处理工艺中的可能。     

Possible solutions for sludge dewatering in China

In China, over 1.43×10⁷ tons of dewatered sewage sludge, with 80% water content, were generated from wastewater treatment plants in 2007. About 60% of the COD removed during the wastewater treatment process becomes concentrated as sludge. Traditional disposal methods used by municipal solid waste treatment facilities, such as landfills, composting, or incineration, are unsuitable for sludge disposal because of its high water content. Disposal of sludge has therefore become a major focus of current environmental protection policies. The present status of sludge treatment and disposal methodology is introduced in this paper. Decreasing the energy consumption of sludge dewatering from 80% to 50% has been a key issue for safe and economic sludge disposal. In an analysis of sludge water distribution, thermal drying and hydrothermal conditioning processes are compared. Although thermal drying could result in an almost dry sludge, the energy consumption needed for this process is extremely high. In comparison, hydrothermal technology could achieve dewatered sewage sludge with a 50%–60% water content, which is suitable for composting, incineration, or landfill. The energy consumption of hydrothermal technology is lower than that required for thermal drying.     

载银TiO_2光催化剂的合成及活性研究

以钛酸四正丁酯为起始原料,采用溶胶-微波法合成出TiO2纳米粒子,借助XRD、UV-Vis吸收光谱等测试手段对其进行了表征,并以罗丹明B为模型污染物考察了酸水比、微波反应温度和微波反应时间等因素对样品光催化性能的影响。结果表明,溶胶-微波法制备TiO2的最佳工艺条件为:酸水比7:1,微波反应温度150℃,反应时间8min。以最佳工艺条件下制备的TiO2为原料,采用光还原法成功制备出载Ag纳米TiO(2摩尔比为1:1),将该光催化剂置于自然光下用于采油厂工业废水的处理,太阳光下照射10h,COD去除率达到92.35%。     

由天然钠基膨润土直接合成钛柱撑膨润土的研究

以高庙子天然钠基膨润土为原料,钛酸正丁酯在pH=2~5环境下水解聚合成柱撑剂,水热法制备了钛柱撑膨润土(Ti-pillaredclay,Ti-PILC)。采用X-射线粉晶衍射(XRD)、扫描电镜(SEM)、比表面积分析仪(BET)分析了产物的结构和形貌。探讨了制备Ti-PILC的工艺参数对结构的影响。结果表明:Ti-PILC呈片层桥结的多孔结构;钛柱撑剂撑开的d001层间距为1.860 8~2.481 3 nm;比表面积由31 m2/g增加到191 m2/g。柱撑最佳工艺参数为:钛/土比30 mmol/g,反应时间为3 h,反应温度为100℃。     

江西潭坑铅锌(银)矿床特征及成因分析

江西省潭坑铅锌(银)矿区位于北武夷铅锌银成矿带内,本文系统阐述了矿区地质和矿床特征,并对矿床的成因进行了探讨。认为本区铅锌(银)矿床,经历了火山喷发沉积和后期热液充填两大成矿期,与次火山岩体(流纹斑岩)有密切的关系,属次火山热液矿床。     

Photocatalytic degradation of Rhodamine B bymicrowave-assisted hydrothermal synthesized N-doped titanate nanotubes

Microwave-induced nitrogen-doped titanate nanotubes（NTNTs） were characterized by transmission electron microscopy（TEM）, X-ray diffraction（XRD）, X-ray photoelectron spectroscopy（XPS）, Fourier transform infrared spectroscopy（FT-IR）, Zeta potential analysis,specific surface area（SBET）, and UV-Visible spectroscopy. TEM results indicate that NTNTs retain a tubular structure with a crystalline multiwall and have a length of several hundred nanometers after nitrogen doping. XRD findings demonstrate that the crystalline structure of NTNTs was dominated by anatase, which is favored for photocatalytic application. The Ti-O-N linkage observed in the XPS N 1s spectrum is mainly responsible for narrowing the band gap and eventually enhancing the visible light photoactivity. FT-IR results demonstrated the existence of H3O＋, which could be excited by photo-generated holes to form hydroxyl radicals and degrade environmental pollutants. After sintering at 350°C, the UV-Vis absorbance edges of NTNTs significantly shift to the visible-light region, which indicates N atom doping into the nanotubes. Photocatalytic degradation of Rhodamine B（RhB） via NTNTs show good efficiency, with pseudo first-order kinetic model rate constants of 3.7 × 10-3, 2.4 × 10-3and 8.0 × 10-4sec-1at pH 3, 7, and 11, respectively.     

天然沸石结构对合成分子筛吸附脱氮性能影响

针对污水厂尾水深度脱氨问题,从国内几个典型的天然沸石矿床中选取了4种天然沸石（记为A、B、C、D）,运用直接碱溶-水热晶化合成工艺制备分子筛,测定了各自的氨氮吸附性能;并采用XRF、XRD等表征方法,对比分析了4种天然沸石在元素组成及矿物含量方面的差异,结合4种合成产物的晶体结构、元素组成、表面形貌分析结果,探讨了天然沸石材料特性对合成产物吸附性能的影响.结果表明：与沸石原料相比,4种合成产物的氨氮吸附性能均得到明显提升,其中C和A沸石合成产物的氨氮吸附量较高,均达到15mg/g以上;合成产物的氨氮吸附性能与沸石原料的碱溶性硅溶出量有正相关关系;碱溶性硅主要来自于天然沸石原料中的方石英、斜发沸石、丝光沸石、透长石等矿物组分,而结构稳定的石英不易被碱溶活化利用.合成产物为含有不同类型分子筛及其它矿物成分的混合物,碱溶性硅溶出量高的C和A沸石均合成了A型、X型分子筛,氨氮吸附性能较好;而B和D沸石合成产物主要为孔径小于铵根离子粒径的方钠石分子筛,其氨氮吸附性能较差.因此,利用天然沸石合成分子筛用于污水脱氨时,应尽量选择石英矿物含量少、碱溶性矿物占比高的沸石原料.     

海底热液系统微生物活动与地球化学的耦合作用评述

热液系统微生物能适应海底极端环境,通过化能合成自养过程,利用多种无机能量生长繁殖。海底热液生态系统的运转主要依靠地球化学和矿物学体系维持,热液系统地球化学和微生物活动之间存在着紧密的耦合关系。一方面,硫化物矿物、金属离子和溶解气体为热液体系微生物的生存和繁殖提供所需能源、碳源和微量元素。热液生态系统的生产力和群落结构在很大程度上受制于地球化学能量向有机体的转移过程。另一方面,微生物对热液流体化学和矿物学也产生重要的影响,生命对热液系统无机部分的改造同样不可忽视。作为一种"复杂的地质生物体系",海底热液体系中各种有机和无机单元是通过多种生化控制和反馈作用相互联系起来的。本文评述了海底热液系统中微生物活动与无机环境相互作用研究的若干进展。     

3D介孔TiO_2微米球的制备及其光催化降解双酚A的研究

利用水热方法,无需模板一步合成3D介孔TiO2光催化剂.然后采用X射线衍射（XRD）、透射电子显微镜（TEM）、高分辨电子显微镜（HRTEM）和N2吸附-解吸BET技术对其组织结构进行表征,以双酚A为目标物对比介孔TiO2光催化剂和市售P25的光催化性能,并研究了不同温度下TiO2的相变及热重分析（TGA）.结果表明,...     

水热/臭氧预处理促进餐厨垃圾中典型废弃油脂厌氧发酵产甲烷

为了缓解餐厨垃圾中大量未降解油脂包覆微生物,对厌氧发酵产生严重抑制的问题,本文采用水热或臭氧预处理有效降解油脂,预处理进行厌氧发酵.扫描电子显微镜和傅里叶变换-红外光谱分析表明,经过水热或臭氧预处理后,厌氧发酵过程油脂降解程度提高.经过臭氧预处理的火锅废油厌氧发酵甲烷产率提升至(854.20±10.28)mL·g-1(...