碘掺杂TiO2可见光光催化性能研究

在低于100℃温度条件下,采用溶胶-凝胶法以钛酸正丁酯为钛源,碘酸钾为碘源,制备了I掺杂纳米TiO2催化剂(I-TiO2),运用X-射线衍射(XRD)、透射电镜(TEM)及X-射线光电子能谱(XPS)等对催化剂进行表征,结果表明,TiO2及I-TiO2催化剂均为锐钛矿,I吸附并包裹在TiO2表面或以间隙进入的形式存在,并未进入TiO2晶格。通过在可见光照射下(λ>420 nm)以罗丹明B(Rhodamine B,RhB)的光催化降解为探针反应研究了在不同条件下制备催化剂的催化性能,结果表明,掺杂比为nI:nTi=0.05∶1,焙烧温度为400℃,降解介质条件pH=7时,I-TiO2光催化活性明显优于未掺杂的TiO2。光催化降解过程通过红外光谱(IR),总有机碳(TOC)跟踪测定,比较了TiO2掺杂前后降解RhB和对氯苯酚(4-CP)的光催化特性差异;同时采用苯甲酸荧光光度法跟踪测定体系中的氧化物种,表明在可见光下,I-TiO2光催化体系中产生.OH高活性氧化物种从而氧化降解目标化合物。     

低曝气下PAC强化SBR工艺同步脱氮除磷

采用序批式反应器(SBR)处理模拟生活污水,研究不同曝气量(30、24、18和12 L/h)下活性污泥同步脱氮除磷规律,并在最佳曝气量下,比较了粉末活性炭-序批式反应器(PAC-SBR)和SBR的脱氮除磷效率,分析了低曝气下PAC-SBR的运行特性和优越性。实验结果表明,当曝气量为24 L/h时,SBR内出水效果较好,其COD、TN和TP的平均去除率分别可以达到90.02%、81.13%和88.12%。在这个最佳曝气量下,PAC-SBR具有明显的优势,其COD、TN和TP的平均去除率均高于SBR,并且PAC-SBR具有较好的污泥沉降性能和较高的活性污泥浓度。在PAC-SBR中,活性污泥以PAC作为微生物载体强化了生物降解效果,并改善了低曝气下污泥絮体的结构,促使反应器内先后形成缺氧-厌氧-微氧/缺氧-缺氧的环境,利于同步硝化反硝化和反硝化聚磷,提高了PAC-SBR的同步脱氮除磷效率。     

氟化工建设项目清洁生产评价

针对某大型氟化工项目,从氟化工产业链的发展、清洁生产控制指标、持续清洁生产等方面分析评价了该企业所采取的清洁生产措施。指出企业在以后的生产过程中应密切关注产品生产新工艺的进展,研究对原有工艺参数的优化,完善环境管理制度,不断探索先进的管理经验,从源头消减污染物的产生量,提高企业经济效益。     

Effects of submerged macrophytes on the abundance and community composition of ammonia-oxidizing prokaryotes in a eutrophic lake

Abundances and community compositions of ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) in unvegetated sediment and the rhizosphere sediments of three submerged macrophytes (Ceratophyllum demersum, Vallisneria spinulosa, and Potamogeton crispus) were investigated in a large, eutrophic freshwater lake, Lake Taihu. Abundances of archaeal ammonia monooxygenase alpha-subunit (amoA) gene (from 6.56?×?10⁶ copies to 1.06?×?10⁷ copies per gram of dry sediment) were higher than those of bacterial amoA (from 6.13?×?10⁵ to 3.21?×?10⁶ copies per gram of dry sediment) in all samples. Submerged macrophytes exhibited no significant effect on the abundance and diversity of archaeal amoA gene. C. demersum and V. spinulosa increased the abundance and diversity of bacterial amoA gene in their rhizosphere sediment. However, the diversity of bacterial amoA gene in the rhizosphere sediments of P. crispus was decreased. The data obtained in this study would be helpful to elucidate the roles of submerged macrophytes involved in the nitrogen cycling of eutrophic lake ecosystems.     

废环氧树脂/PVC复合材料的性能

将废环氧树脂与聚氯乙烯(PVC)共混,采用模压工艺制备复合材料。通过正交实验,讨论废环氧树脂添加量、硅烷偶联剂KH-550用量、模压时间3个因素对复合材料力学性能的影响大小,得到其优化条件。在正交实验所得优化条件基础之上,研究单因素对复合材料的影响,最终确定实验的最优方案。结果表明:当模压时间10 min,废环氧树脂添加量70%,硅烷偶联剂用量2份时,复合材料的力学性能达到最优,冲击强度为10.49 kJ/m2,拉伸强度为62.24 MPa。     

塔里木油田钻井废物处理技术研究

为实现钻井废物随钻即时处理,采用钻井废物处理技术。研究对钻井废物实验取样,将废物分离成岩屑、泥饼和水,对泥浆中的固体通过水洗、絮凝分离和化学反应处理,泥浆中的有害物质成分和氯离子被析出后,再用真空吸附脱水制成泥饼,同时将水循环利用。根据实验数据对本底值以及处理前后的数据进行对比分析,验证了该技术在塔里木油田的适用性。     

Sources and distribution of polychlorinated-dibenzo-p-dioxins and -dibenzofurans in soil and sediment from the Yellow Sea region of China and Korea

Polychlorinated-dibenzo-p-dioxins and -dibenzofurans (PCDD/Fs) were measured in soils and sediments from the Yellow Sea region. Korean soils and sediments mostly contained detectable PCDD/Fs and showed a widespread distribution among locations. Soil and sedimentary PCDD/Fs from China were comparable to or less than those in Korea. The patterns of relative concentrations of individual congeners in soils were different between the two countries, but similar in sediments. Sources of PCDD/Fs in China and Korea were found to be independent of each other and their distributions reflected matrix-dependent accumulation. Spatial distribution indicated some point sources in Korea while Chinese sources were more widespread and diffuse. PCDD/Fs measured in the coastal areas of the Yellow Sea were comparable to or less than those previously reported in for eastern Asia. However, ∑TEQs in soils and sediments were near to or, in some cases exceeded environmental quality guidelines.     

Distribution, speciation and availability of antimony (Sb) in soils and terrestrial plants from an active Sb mining area

Here, we present one of the first studies investigating the mobility, solubility and the speciation-dependent in-situ bioaccumulation of antimony (Sb) in an active Sb mining area (Xikuangshan, China). Total Sb concentrations in soils are high (527-11,798 mg kg⁻¹), and all soils, including those taken from a paddy field and a vegetable garden, show a high bioavailable Sb fraction (6.3-748 mg kg⁻¹), dominated by Sb(V). Elevated concentrations in native plant species (109-4029 mg kg⁻¹) underpin this. Both chemical equilibrium studies and XANES data suggest the presence of Ca[Sb(OH)₆]₂, controlling Sb solubility. A very close relationship was found between the citric acid extractable Sb in plants and water or sulfate extractable Sb in soil, indicating that citric acid extractable Sb content in plants may be a better predictor for bioavailable Sb in soil than total acid digestible Sb plant content.     

La-Ce-attapulgite催化分解NO的研究

采用化学共混法制备系列La-Ce-attapulgite催化剂,并在固定床反应器中进行NO催化分解性能测试.实验考察了稀土加入量、La/Ce配比、共混液pH值和催化剂的活化煅烧温度等制备条件对催化剂脱硝性能的影响.结果表明:稀土加入量为2%,共混液pH=7,La/Ce比值为LaxCe(1-x)(x=0.5),煅烧温度4...     

微波活化法制备加拿大一枝黄花活性炭及其性能表征

利用入侵植物加拿大一枝黄花为原料,采用在400℃氮气保护下,直接碳化90 min后,选择KOH为活化剂,微波活化的方法制备活性炭.研究了不同的KOH/C比值、微波功率及活化时间对活性炭吸附量及产率的影响.结果表明,最优活化条件为碱碳比2g/g、微波功率700w及微波辐射6 min,此时活性炭的亚甲基蓝吸附值、碘吸附值、...