Tools for an enhanced solvent properties screening in the early stages of pharmaceutical process development

The objective of this research was the implementation of tools for the evaluation of solvents trough property screening in the early stages of process development. An important feature of the tools is that the implementation of indexes, scores, or weights is avoided. Information already available from the literature was stored in a database in order to turn raw data into decision making information. As a result, a solvent radar chart, a solvent representation table, and a solvent telescopying tool were developed in an ASP.NET application. The synthesis of Propranolol was used as study case in order to explore the selection of solvents in the early stages of process development. The replacement of diethyl ether was possible in the extraction step, while solvent choices were detected for potential telescoping for extraction and crystallisation steps. Solubility was found as a critical parameter in telescoping analysis. The methodology proposed enhanced the view towards a more holistic perspective and a more robust solvent screening process. As a consequence, the next steps into solvent evaluation and process development can be reduced.     

Trends of chemical speciation profiles of anthropogenic volatile organic compounds emissions in China, 2005–2020

This study estimates the detailed chemical profiles of China＇s anthropogenic volatile organic com- pounds （VOCs） emissions for the period of 2005-2020. The chemical profiles of VOCs for seven activity sectors are calculated, based on which the Photochemical Ozone Creation Potential （POCP） of VOCs for these sectors is evaluated. At the national level, the VOCs species emitted in 2005 include alkanes, alkenes and alkynes, aromatic compounds, alcohols, ketones, aldehydes, esters, ethers and halocarbons, accounting for 26.4wt.%, 29.2wt.%, 21.3 wt.%, 4.7 wt.%, 5.4 wt.%, 1.7 wt.%, 2.1 wt.%, 0.7 wt. % and 2.2wt.% of total emissions, respectively. And during 2005-2020, their mass proportions would respec- tively grow or decrease by - 34.7%, -48.6%, 108.5%, 6.9%, -32.7%, 7.3%, 65.3%, 100.5%, and 55.4%. This change would bring about a 13% reduction of POCP for national VOCs emissions in the future. Thus, although the national VOCs emissions are expected to increase by 33% over the whole period, its ozone formation potential is estimated to rise only by 14%. Large discrepancies are found in VOCs speciation emissions among provinces. Compared to western provinces, the eastern provinces with a more developed economy would emit unsaturated hydrocarbons and benzene with lower mix ratios, and aromatic compounds except benzene, oxidized hydrocar- bons and halocarbons with higher mix ratios. Such differences lead to lower POCP of VOCs emitted in eastern provinces, and higher POCP of VOCs emitted in western provinces. However, due to the large VOCs emissions from Chinese eastern region, the ozone forma- tion potential of VOCs emission in eastern provinces would be much higher than those in western provinces by about 156%-235%.     

包装印刷业VOCs污染特征分析

选取了北京市的14家大型包装印刷企业进行现场采样、监测,统计分析了生产工艺和原辅材料,识别了VOCs污染来源和排放节点。根据不同排放节点的特征搭建了相应的采样系统,并以此为基础考察了VOCs的排放特征、臭氧生成潜势和二次有机气溶胶(SOA)生成潜势。结果表明:包装印刷业所排放的VOCs以醇类和酯类为主;乙醇和异丙醇为主要的臭氧前体物,生产线和烘干集气系统排气口为主要的臭氧生成节点;烷烃和醇类为主要的SOA前体物,烘干集气系统排气口为首要的SOA生成节点。     

石化企业循环水的VOCs成分谱

采用顶空-气相色谱-质谱联用技术,针对3家石油化工企业的38个循环水样进行了VOCs的定性、定量分析。结果表明,石化企业循环水中主要含有烷烃、烯烃、卤代烃、芳香烃、含氧有机物等5类物质,其中卤代烃占总量的67%(w),芳香烃化合物占24%(w),烃类化合物、含氧化合物含量比较低,分别占4%(w)。本研究进一步完善了我国VOCs排放源成分谱,同时也为石化企业循环水中VOCs的管控提供了数据支持。     

挥发性有机物和臭味的生物过滤处理

生物过滤法是一种较新的空气污染控制方法 ,它利用微生物降解或 /转化空气中的挥发性有机物以及硫化氢、氨等恶臭物质。本文主要介绍生物过滤法处理废气的基本原理 ,讨论填料种类、湿度、pH、温度等影响生物过滤法性能参数。同时综述了生物过滤法的应用范围以及对生物过滤法的改进。     

土壤理化条件变化对含硫气体释放的影响

研究在不同的室内培养条件下,土壤的各种物理化学条件对含硫气体释放的影响．结果表明,土壤在含水率为50%～75%,ｐＨ＝3.25～8.67,较大的Ｃ:Ｎ 条件下,各含硫气体的释放量较大．而光照条件对于不同的硫源释放含硫气体的情况各有不同．环境条件通过改变微生物的活动改变了各硫源的生化分解的产硫量     

太湖梅梁湾沉积物中酸挥发性硫化物垂直变化特征研究

水体沉积物中的酸溶性硫化物 (AVS)极易与二价金属阳离子反应生成难溶金属硫化物 ,从而控制沉积物中二价有毒金属的化学活性和生物有效性 .测定沉积物中的AVS和同步提取金属 (SEM) ,依据SEM AVS的比值可作为判定重金属生物有效性的良好指标 .通过对太湖梅梁湾 2个不同站点沉积物中AVS与SEM随深度分布的研究得出 :①AVS含量随着深度的加深先上升后降低 ,SEM含量随深度的加深呈逐渐降低趋势 ;②SEM AVS只在最表层 (0～ 2cm)大于 1,低于这一层都小于 1.③在表层沉积物 (0～ 2cm)中 ,可能存在重金属生物毒性效应 .但对于单个金属而言 ,Ni、Cu具有产生毒性作用的潜能 ,而Zn、Pb对沉积物中的生物不具有毒性 .     

室内空气污染分析方法研究进展

本文对室内空气污染分析方法进行了详细综述 ,以期对开发室内空气污染分析的新方法及新技术提供参考。     

生物法处理挥发性有机废气的研究

生物法处理被污染的空气这一技术已经被德国和荷兰成功地运用了 2 0年之久 ,但是在国内还属于一种较新的空气污染治理技术。本文主要概述了有机废气生物处理的 3种主要形式 :生物滤池、生物滴滤塔和生物洗涤器的原理、流程和几种影响反应器性能的因素 ,并比较了以上 3种反应器及其不同支撑材料的优缺点。目前 ,气态生物反应器主要以通用的指导方针、试验性的研究和来自类似应用的经验为基础进行设计的。     

生物滴滤池法处理有机废气甲苯工艺填料的选择

生物滴滤池法处理挥发性有机污染物的研究是世界工业废气净化的前沿热点之一，本研究比较了阶梯环，聚乙烯小球，煤炭渣和某种活性炭附着纤维作为滴滤池中生物附着载体性能的优劣，结果表明，活性炭附着纤维填料系统具有较好的有机污染物去除能力。