2-(2-喹啉偶氮)-4-二乙氨基苯甲酸光度法测定镍的研究

合成了新试剂 2 -( 2 -喹啉偶氮 ) -4 -二乙氨基苯甲酸 ( QADEABA) ,并研究了其与镍的显色反应 ,在 p H=8.0的硼酸 -磷酸二氢钾缓冲介质中 ,吐温 -80存在下 ,QADEABA与镍反应生成 2∶ 1稳定络合物 ,λmax=5 90 nm ,ε=1 .1 8× 1 0 5L· mol-1· cm-1。镍含量在 0～ 0 .4 mg/ L内符合比耳定律 ,方法用于水样中镍含量的测定 ,结果令人满意     

气相分子吸收光谱法测定海水中亚硝酸盐氮

采用气相分子吸收光谱仪测定海水中亚硝酸盐氮,方法在低浓度(0.00~0.50 mg/L)和高浓度(0.00~2.00 mg/L)范围内均具有良好的线性,线性相关系数R2均≥0.999 7,检出限为0.003 mg/L,准确度和精密度良好。用本法与国标法(萘乙二胺分光光度法)同时测定若干实际海水样品中亚硝酸盐氮,两种方法的测定结果相对偏差为0.00%~4.90%。对两组测定结果进行线性拟合,结果显示相关系数R2为0.998 7,说明两组测定结果具有良好的一致性。相比国标法,气相分子吸收光谱法具有操作简单、分析快速准确、干扰少等优点,能够替代国标法。     

远程监控城乡管网饮用水的低量色度

选用480 nm单色光及长光程技术进行吸光光度分析,测定水质色度。通过对比普通分光光度法可知,吸光光度测试的光程长度增加10倍,测试灵敏度显著提高,从而保证低色度饮用水(30度)的测定精准度。监测的色度数据利用GSM无线通信传输系统,可实现对水质色度监测结果的远程实时动态遥传,为预警突发性水污染事故提供数据支撑。     

水浮莲干体吸附去除水中的锑(Ⅲ)

以水浮莲干体为生物吸附剂,考察不同吸附时间、初始pH、水浮莲干体量、摇床转速和反应温度等因素对废水中锑(Ⅲ)的吸附影响;同时通过FTIR、动力学模型以及等温吸附模型等对吸附机理进行研究。结果表明:Sb3+初始浓度为50 mg/L、溶液初始pH为6.8、水浮莲干体用量为1.0 g/25 mL、于(25±1)℃的恒温振荡摇床中以100 r/min振荡吸附反应120 min后,吸附率可达76.8%。水浮莲干体对Sb3+的吸附是一个快速的过程,前10 min的吸附率为52.7%,60 min达到吸附平衡;初始pH对Sb3+的吸附有显著的影响,适宜pH为6.8;在一定范围内,干体量的增加、摇床转速的增大以及温度的升高都会导致吸附率升高。结合FTIR谱图分析得出吸附为化学、物理吸附;准二级动力学模型比准一级动力学模型能更好地描述水浮莲干体对Sb3+的吸附过程;Langmuir和Freundlich吸附等温模型均适合对吸附过程进行拟合,但Lang-muir模型能更好地反映吸附特性,298 K时最大吸附量为1.394 mg/g。水浮莲干体对Sb3+有良好的吸附效果,可用于处理含锑废水,达到以废治废的目的。     

填埋垃圾中TOC含量的测定方法优化

垃圾的TOC含量是评价垃圾矿质腐殖化机理研究的重要指标,以本课题组模拟垃圾填埋系统中的垃圾样品为研究对象,以土壤TOC测定方法为基础,通过单因素实验和正交实验(L25(56))对垃圾样品的TOC的测定方法进行优化。结果表明,TOC测定优化条件为:风干样品(0.1±0.0005)g,Ag2SO40.075 g,0.4 mol/L(1/6K2Cr2O7)-H2SO4溶液(含1/2H2SO412.6 mol/L)10 mL,180℃的砂浴加热45 min。此条件下,RSD小于3.23%,表明该方法精密度高,可行性强。     

活性炭纤维低温脱除模拟烟气中的VOC

采用H2O2浸渍的修饰方法对ACF进行化学改性,并利用氮吸附等温线和XPS（X-ray photoelectron spectroscopy）的方法对ACF样品进行表征。通过在反应床上开展吸附实验,由此测定改性前后ACF脱除VOC（甲苯作为VOC的代表物）的效果,同时考察氧气、温度、水蒸气等因素对ACF脱除甲苯的影响。研究发现,改性使得ACF样品比表面积和孔容略有降低,但表面含氧官能团含量增加,吸附甲苯的能力也因此增强。当模拟烟气中O2浓度为5%时,ACF脱除VOC效果达到最佳,超过5%之后,氧的促进效果不再明显;温度40℃为最佳吸附温度;当烟气中加入水蒸气时,ACF对VOC的脱除效率降低。     

Predicting regional space–time variation of PM2.5 with land-use regression model and MODIS data

Purpose  

Existing land-use regression (LUR) models use land use/cover, population, and traffic information to predict long-term intra-urban variation of air pollution. These models are limited to explaining spatial variation of air pollutants, and few of them are capable of addressing temporal variability. This article proposes a space–time LUR model at a regional scale by incorporating aerosol optical depth (AOD) data from the Moderate Resolution Imaging Spectroradiometer (MODIS).     

Mercury speciation and mobility in mine wastes from mercury mines in China

Mercury (Hg) speciation and mobility were determined in calcines and waste rocks collected from 9 Hg mines in China. Total Hg (THg) concentrations in the mine wastes varied widely in different Hg mines (with a range of 0.369 to 2,620 mg kg^?1). Cinnabar is the dominant form of Hg in the mine wastes. However, Hg²⁺ and Hg⁰ concentrations in the calcines were significantly higher than these in the waste rocks, which suggested the retorting can produce large amounts of by-product Hg compounds. The THg and Hg⁰ concentrations in certain mine wastes exceeded soil guidelines recommended by US Environmental Protection Agency; while total soluble Hg concentrations of leachates in certain mine wastes exceeded National Surface Water Quality Standard of China. Mine wastes are important Hg pollution sources to the aquatic ecosystem and atmosphere.     

Reducing the pollution risk of pesticide using nano networks induced by irradiation and hydrothermal treatment

Traditional pesticides (TP) often do not adhere tightly to crop foliage. They can easily enter the surrounding environment through precipitation and volatilization. This can result in the pollution of the surrounding soil, water, and air. To reduce pesticide pollution, we developed a loss-control pesticide (LCP) by adding attapulgite with a nano networks structure fabricated using high energy electron beam (HEEB) irradiation and hydrothermal treatment to TP. HEEB irradiation effectively dispersed originally aggregated attapulgite through modified thermal, charge, and physical effects. Hydrothermal treatment further enhanced the dispersion of attapulgite to form nano porous networks via thermal and wet expansion effects, which are beneficial for pesticide binding. An LCP has improved retention on crop leaf surfaces. It has a higher adhesion capacity, reduced leaching and volatilization, and extended residual activity compared with the TP formulation. The treatment increases the residual activity of pesticides on crop foliage and decreases environmental pollution.