Formation of multiple trimethylsilyl derivatives in the derivatization of 17α-ethinylestradiol with BSTFA or MSTFA followed by gas chromatography-mass spectrometry determination

N,O-bis(trimethylsily)trifluoroacetamide (BSTFA) and N-methyl-N(trimethylsily) trifluoroacetamide (MSTFA) are common derivatization reagents used in the GC-MS analysis of estrogen steroids such as estrone (E1) and 17(-ethinylestradiol (EE2). In this study, three trimethylsilyl (TMS) steroid derivatives, mono-and di-trimethylsilyl EE2 and mono-trimethylsilyl E1, were observed during the derivatization of EE2 with BSTFA or MSTFA and/or GC separation. Factors influencing the production of multiple TMS derivatives and their relative abundance were examined. It was found that both methanol and bisphenol A competed with estrogenic esteroids when reacting with silylation reagents, and thus affected the formation of TMS derivatives and their relative abundance in the derivatization products. Methanol was found to be more reactive than bisphenol A with the BSTFA reagent. None of the three solvents tested in this study could prevent the generation of multiple TMS derivatives during the derivatization of EE2 with BSTFA, followed by GC analysis. A similar result was observed using MSTFA as the derivative reagent followed by GC analysis. Thus, the suitability of BSTFA or MSTFA as the derivatization reagent for the determination of E1 and EE2 by GC-MS, under the conditions reported here, is questionable. This problem can be solved by adding trimethylsilylimidaz (TMSI) in the BSTFA reagent as recommended, and the performance of the method has been proved in this study.     

Anoxic biodegradation of dimethyl phthalate （DMP） by activated sludge cultures under nitrate-reducing conditions

Worldwide extensive use of plasticized plastics has resulted in phthalates pollution in different environment. Nitrates from industry and agriculture are also widely disseminated in the soils, natural waters and wastewaters. Dimethyl phthalate (DMP) biodegradation by activated sludge cultures under nitrate-reducing conditions was investigated. Under one optimized condition, DMP was biodegraded from 102.20 mg/L to undetectable level in 56 h under anoxic conditions and its reaction fitted well with the first-order kinetics. Using the high-performance liquid chromatography (HPLC) and liquid chromatography mass spectrometry (LC-MS) analysis, mono-methyl phthalate (MMP) and phthalic acid (PA) were detected as the major intermediates of DMP biodegradation. When combined with the determination of chemical oxygen demand (CODCr) removal capacity and pH, DMP was found to be mineralized completely under anoxic conditions. The biodegradation pathway was proposed as DMP → MMP → PA → … → CO2 H2O.The molar ratio of DMP to nitrate consumed was found to be 9.0:1, which agrees well with the theoretical stoichiometric values of DMP biodegradation by nitrate-reducing bacteria. The results of the non-linear simulation showed that the optimum pH and temperature for the degradation were 7.56 and 31.4℃, respectively.     

生态工业园运行效率评价指标体系的研究

生态工业园是实现可持续发展的有效模式.在国内外生态工业园评价指标体系研究的基础上,对生态工业园运行效率的内涵进行了研究与界定,阐明了生态工业园运行效率的表现特征,围绕其表现特征,设置了包含经济运行效率、资源转化效率、污染减排效率、生态工业特征指标和园区管理效率5个准则层在内的指标体系,并对指标的选取、评价标准的制定进行了讨论,最终建立了包含27个具体指标的生态工业园运行效率评价指标体系.以烟台经济技术开发区生态工业园为例,采用层次分析法和距离函数模型等数学方法对园区的运行效率进行了评价,针对评价结果,从园区管理、生态工业特征等方面提出了开发区今后发展的对策与建议,也为其他生态工业园区的运行效率评价提供了有用的参考.     

医院手术室火灾预防应对策略研究

随着可燃性吸入麻醉药、激光及电凝电切设备在医院手术室内的广泛应用,发生在医院手术室内的火灾具有其特殊性.一旦发生火灾时,对于正在接受手术的患者而言,由于其处于全麻或局麻的非全清醒状态,意识及行动高度受限,可能对其造成极度其严重的伤害.因此,控制手术室内火灾和爆炸危险对于手术室工作人员极为重要.     

郑汴路不同运营路段路旁土壤重金属分布及污染分析

选择运营时间不同的杏花营和圃田路段分别布设1800 m长的采样断面,按距离路基远近不同布设土壤采样点38个,对照采样点2个,在距路基25 m处挖掘土壤剖面2个,共采集土壤样品50个.在室内试验的基础上,对路旁土壤重金属(Pb、Cd、Ni、Cu、Zn、Cr)空间分布特征与污染状况进行了研究.结果表明,公路两侧300 m范围内的土壤重金属含量明显高于对照区和中国潮土背景值,尤其土壤中Cd、Cr和Pb积累明显.路北土壤重金属含量高于路南.对于运营时间长的杏花营断面,土壤重金属含量高于圃田断面.大多数重金属在土壤中的含量随离公路距离的增加在距路基10～50 m处出现积累峰值,然后逐渐下降,在300 m附近接近于对照值.重金属主要累积在土壤深0～40 cm范围内.杏花营路段两侧200 m范围内为重金属轻度污染带,200～300 m之间为警戒带.圃田路段北侧30 m范围内为轻度污染带,30～200 m为警戒带,200～300 m为清洁带;而其南侧15 m范围内为轻污染带,15～80 m为清洁带,80～300 m为警戒带.     

超滤膜在新疆污水处理中的应用研究

超滤膜能有效去除大肠杆菌、细菌、SS等污染物质,并对COD和BOD也有一定的去除效果。由于新疆特殊的气候原因,导致新疆的污水水质与内地差异较大,因此采用超滤膜对新疆疾病控制中心生活污水处理站二级生化处理达标外排水进行深度处理,分别进行了管路流体力学特性实验、超滤膜截留特性实验、膜污染实验、膜的清洗实验等,掌握了膜污染变化规律和污染防治方法．为日后的此类工程设计提供了参考数据．     

SBR工艺运行条件对好氧污泥颗粒化和除磷效果的影响

采用模拟配制生活污水,研究循序间歇反应器(SBR)工艺在不同运行条件下对好氧污泥颗粒化和生物除磷效果的影响.试验分别对进水中不同COD/TN比(11.79,18.85,20.72,24.66)、COD/TP比(27.85,44.53,48.93、58.25)、TN/TP比(4.00,2.36,1.54)、温度(22℃,15℃,8℃)和污泥龄(16d,10d,5d)作比较,发现进水中较高的COD/TN比(24.66)、COD/TP比(58.25)、温度(22℃)和较低的污泥龄(10d)对生物除磷和颗粒的形成有利;适当的TN/TP比(2.36)、接种污泥的选择是好氧颗粒污泥形成的关键.     

热解条件对生物炭性质和氮、磷吸附性能的影响

以橡木为原料,在不同的热解终温、升温速率和恒温时间下制备生物炭.对生物炭产率、p H、元素组分、工业组分、比表面积、红外光谱等理化特征进行分析,并考察生物炭对水溶液体系中NO-3-N、NH+4-N、PO3-4-P的吸附性能.结果表明:生物炭的产率受热解终温影响最大(极差:54.57%),恒温时间次之(极差:1.16%),升温速率最小(极差:0.42%).随热解终温、升温速率和恒温时间的增加,所得生物炭的p H和C含量增加,而H和O含量降低.热解终温对生物炭表面官能团影响较大,升温速率和恒温时间基本无影响.生物炭对氮、磷的吸附性能主要受热解终温影响.NO-3-N的吸附量最大可达2.80 mg·g-1(600℃),且随热解终温的升高呈指数增加.比表面积、表面碱性官能团和表面金属氧化物与NO-3-N吸附有关.随热解终温的增加,NH+4-N吸附量降低,最大吸附量为3.12 mg·g-1(300℃).阳离子交换量(CEC)是影响NH+4-N吸附的主要因素.PO3-4-P吸附量随热解终温的增加呈先增后减的趋势(在500℃达到最大,为9.75 mg·g-1),且吸附过程主要受生物炭表面碱性官能团和表面金属氧化物的影响.     

天津大气扩散条件对污染物垂直分布的影响研究

利用2017~2019年夏、冬季天津市大气污染物监测和气象观测数据,基于天津气象铁塔垂直观测,针对大气垂直扩散条件对PM_2.5和O₃的影响进行研究.结果显示:近地面PM_2.5浓度随高度的升高而下降,O₃浓度则随高度的升高而上升,受大气垂直扩散条件的季节和日变化影响,冬季,地面与120m PM_2.5质量浓度相关明显,与200m PM_2.5质量浓度无明显相关.夏季,120m和200m PM_2.5质量浓度相关系数为0.72,午后通常出现120m和200m PM_2.5质量浓度高于地面的情况.夏季,不同高度O₃浓度差异小于冬季,地面与120m高度O₃浓度接近.以大气稳定度、逆温强度和气温递减率作为大气垂直扩散指标,对地面PM_2.5和O₃垂直分布具有指示作用.冬季,TKE与PM_2.5质量浓度相关系数为到-0.65,夏季,TKE与ΔPM_2.5相关系数为-0.39.夏、冬季TKE与地面O₃浓度的相关系数分别为0.46和0.53,与ΔO₃的相关系数分别为0.73和0.70.弱下沉运动对地面O₃浓度影响较强,40m高度垂直运动速度与地面O₃浓度的相关系数在冬、夏季分别为-0.54和-0.61.对冬季典型PM_2.5重污染过程的分析发现,雾霾的生消维持和PM_2.5浓度的变化与大气稳定度、气温垂直递减率和TKE的变化有直接关系.对夏季典型O3污染过程的分析发现,近地面的O₃污染的形成与有利光化学反应的气象条件密切相关,同时,垂直向下输送和有利垂直扩散条件对O₃污染的形成和爆发影响明显.     

聚乙烯醇降解酶酶解聚乙烯醇最优条件研究

为了提高聚乙烯醇(PVA)降解酶的催化降解能力,对假单胞菌Pseudomonas.sp XT11-Z90S产生的聚乙烯醇降解酶的降解条件进行了优化.同时,通过单因素实验研究了PVA浓度、温度、缓冲液pH对降解酶活性及PVA降解率的影响.最后,应用响应面分析方法对影响聚乙烯醇降解酶酶活的3个因素进一步优化.结果表明,单因素实验得出的适宜PVA浓度、温度、pH分别为1.0g·L-1、50℃、7.0.响应面分析法得出的最适的降解条件为:PVA浓度0.84g·L-1,温度53.5℃,pH值6.8.在最优条件下,PVA降解酶酶活达到了20.3U.mL-1,比优化前的12.2U.mL-1提高了66.4%.且6h后其降解率达到了52.6%.