A new technique helps to uncover unknown peptides and disinfection by-products in water

正Environmental water samples can be extremely complex,with potentially thousands of molecules that can derive from natural organic matter(NOM)and thousands that derive from anthropogenic contaminants.As complex as these samples are,drinking water can be even more complex.Due to disinfectants that are used to treat drinking water(e.g.,chlorine,chloramines,     

吹扫捕集-气相色谱-质谱联用法测定地表水中1,2-二氯苯和1,4-二氯苯研究

通过吹扫捕集富集地表水中1,2-二氯苯和1,4-二氯苯,解吸后用气相色谱-质谱联用法同时测定,内标法定量,加入硫酸钠提高方法的灵敏度,优化并验证检测方法.1,2-二氯苯和1,4-二氯苯在一定浓度范围内线性关系良好,方法检出限为0.01 μg/L,加标回收率和测定结果的相对标准偏差较好,符合分析测试质量控制要求.具有操作简单、样品用量少、组分损失低、回收率高等优点,不对环境造成二次污染.     

A numerical model for drying of spherical object in an indirect type solar dryer and estimating the drying time at different moisture level and air temperature

A numerical model for simultaneous heat and mass transfer was developed for solar drying of spherical objects and the object considered is green peas. Solar collector outlet temperature is assumed as drying chamber temperature and justified through energy balance equations. Assumptions are imposed on heat and mass transfer governing equations without losing the physics of the problem. Discretization is performed by finite difference method with implicit scheme. To generalize, the governing equation and boundary conditions are non-dimensionalized. The set of finite difference equations was solved by Tridiagonal Matrix Algorithm and a computer code in MATLAB was developed to solve them. The drying curves showed two stages of drying, initial, and secondary drying stage. At all drying temperatures and drying time, the center moisture was maximum and it was minimum at the boundary. A percentage of 85.67 surface moisture content and 25.33% center moisture was eliminated in the first 1 hr at 348 K. The product should be dried up to 7.45, 4.74, and 3.74 hr at air drying temperatures of 318, 333, and 348 K respectively, to maintain 10% of the product’s initial moisture content. The result is compared with the experimental result from literature and they are found to be in good agreement.     

派河及其支流溶解性有机质分子组成特征

溶解性有机质(DOM)是水生生态系统中的重要组成部分,派河作为"引江济淮"清水廊道工程江淮段的唯一输水通道,其DOM分子层面的组成信息和特性尚不明确.利用静电场轨道阱高分辨质谱技术对派河及其支流(光明大堰河)DOM分子进行表征,并且利用皮尔逊(Pearson)相关性分析和主成分分析(PCA)研究两条河流DOM的分子组成...     

出水回流对Anammox颗粒特性及其微生物群落的影响

基于有无回流的EGSB反应器中厌氧氨氧化颗粒污泥的内外部结构和微生物群落差异,从传质、活性和稳定性等角度分析了出水回流对颗粒污泥结构和功能的影响.研究表明,增加回流提供更好的水流条件使得底物能更好的与颗粒污泥接触,反应器在氮负荷率为(3.48±0.32)kg N/(m3·d)的条件下亚硝氮和氨氮的去除率从60％和65％...     

HPLC和GC-MS法测定环境空气中醛酮类化合物比对分析

对2,4-二硝基苯肼吸附衍生-高效液相色谱（DNPH-HPLC）法和罐采样/气相色谱-质谱（GC-MS）法的测定条件进行优化,将两种方法测定环境空气中13种醛酮类化合物（OVOCs）的结果做比对分析。结果表明,HPLC法和GC-MS法均可实现一次进样13种OVOCs全分析,方法检出限分别为0.26μg/m3～1.39μg/m3和0.49μg/m3～1.10μg/m3,加标回收率分别为95.9%～111%和52.0%～138%。两种方法测定实际样品,检出组分的测定结果无显著性差异;HPLC法适合测定环境空气中低碳类（C1～C3）低浓度OVOCs,GC-MS法适合测定多碳类（C4～C8）低浓度OVOCs。     

全自动石墨消解原子吸收法测定土壤中的Pb

建立了用硝酸-氢氟酸-高氯酸体系全自动石墨原子吸收分光光度法测定土壤中的Pb的分析方法。土壤中Pb的检出限可达0.07 mg/kg,线性相关系数为0.9998,加标回收率为92.8%~98.4%。所建立的方法安全、快速、简单、灵敏度高、重现性好,是同时大批量分析土壤中Pb含量的可靠高效方法。     

数字式光学测尘仪对不同呼吸性粉尘浓度转换系数的求取

本文论述了用BY-1型呼吸性粉尘标定采样器,在云南锡业公司矿山和冶炼厂现场测定、求取P-5L_2型和TM型光学测尘仪的读数与呼吸性粉尘(空气动力学直径:<7.07μm和<10μm)质量浓度转换系数(K)的方法和结果.研究表明,由深色矿物组成的粉尘,其K值大于由浅色矿物组成的粉尘的K值.P-5L_2型光学测尘仪间的测尘误差85％以上在±10％以内,平均为±6.68％.     

废水生物处理中生物膜的形成及动力学模型研究进展

综述了生物膜法处理废水中生物膜的形成及其动力学模型。概述了反应器中微生物的固定化即生物膜的形成过程;影响生物膜形成的因素,生物膜的结构及其对生物膜中生化反应和传质过程的影响;并叙述了几种典型的生物膜模型;提出生物膜法废水处理以后的研究重点。      

饱水作用对锁固型岩体变形特性影响研究

为了研究饱水作用对锁固型岩体力学性质和变形特性的影响,对干燥与饱水状态下的岩体进行单轴压缩试验,利用数字图像相关方法对岩体加载过程进行非接触式实时变形监测。研究结果表明：饱水作用弱化了岩体的单轴抗压强度和弹性模量;应变场演化特征表明饱水作用增大试件的变形量,但未改变试件的裂纹扩展路径和最终破坏模式;岩桥锁固段剪切裂纹起裂和峰值应力时伴随着应变场分异速率突增,可作为锁固型岩体滑动和失稳破坏的前兆信号,饱水作用对应变场分异速率峰值有削弱作用;通过计算预制裂隙两侧的错动位移,定量揭示岩体失稳过程中岩桥的“锁固效应”。研究结果可为涉水环境下锁固型岩体的稳定性问题和灾变监测提供参考。