汽车内空气甲醛污染状况及其影响因素分析

为了解车内空气甲醛污染状况及其影响因素,随机测定200辆私家轿车车内空气甲醛浓度、温度和湿度,同时通过问卷调查获得车型、车龄、车内装饰物和关窗时间等基本情况.检测可知,车内空气甲醛几何均数为0.030 mg/m 3 ,95%可信区间为0.027～0.033 mg/m 3 .参照《室内空气质量标准》(GB/T 18883-2002)规定为0.100 mg/m 3 ,超标率为1.5%.车内空气甲醛对数质量浓度(y)与车龄(X 1 )、车内温度(X 2 )、汽车档次(X 3 )、车内温度×关窗时间(X 4 )有关,回归方程为y=-2.088 5-0.096 6X 1 0.019 9X2 0.049 5X 3 0.002 2X 4 .表明车内甲醛污染主要存在于车龄不足半年、关窗时间超过3 h以上的车辆,降低车内温度可有效控制车内甲醛污染.     

尿素和添加剂湿法烟气同时脱硫脱氮工艺研究(Ι)

对尿素和添加剂同时吸收烟气中 SO2 和 NOx 进行了实验研究。结果表明 ,烟气中 SO2 极易脱除 ,在实验条件下 SO2 脱除率均大于 99%,操作工艺条件变化主要是影响 NOx脱除率。尿素和添加剂质量分数对 NOx 脱除率影响较小 ,NOx脱除率随尿素和添加剂质量分数的增加而缓慢增加 ;吸收剂 p H和吸收反应温度对 NOx脱除率有显著影响 ,最佳 p H为 7,最佳反应温度为 70～80℃。     

Quantifying nitrate sources in a large reservoir for drinking water by using stable isotopes and a Bayesian isotope mixing model

Drinking water reservoirs are threatened globally by anthropogenic nitrogen pollution. Hydrochemistry and isotopes were analyzed to identify spatial and temporal varieties of main nitrate sources in a large drinking water reservoir in East China. The results showed that NO₃^? was the main nitrogen form in both the dry and wet seasons, but dissolved organic nitrogen (DON) was increased in the wet season. The δ¹⁵N-NO₃^? values (+?1.3‰ to +?11.8‰) and δ¹⁸O-NO₃^? values (+?2.5‰ to +?13.5‰), combined with principal component analysis (PCA), indicated that chemical fertilizer was the main nitrate source during the dry season, while chemical fertilizer, soil N, and sewage/manure were the main nitrate sources during the wet season in the Qiandao Lake area. And, the nitrate isotopes showed the significant nitrification and assimilation in the Qiandao Lake area. A Bayesian isotopic mixing model (Stable Isotope Analysis in R) was applied to the spatial and seasonal trends in the proportional contribution of four NO₃^? sources (chemical fertilizer (CF), soil nitrogen (SN), sewage and manure (SM), and atmospheric deposition (AD)) in the Qiandao Lake area. It was revealed that CF was the most important nitrate source in the dry season, accounting for 53.4% with 19.2% of SM and 18.9% of SN, while the contribution of SN increased in the wet season, accounting for 31.6%, followed by CF (30.8%) and then SM (24.2%). The main nitrate sources in the urban area, rural area, and central lake area were CF and SN, accounting for 66.1% in the urban area, 71.7% in the rural area, and 68.2% in the central lake area. Measures should be made to improve chemical fertilizer use efficiency and to reduce nitrogen loss in the Qiandao Lake area.

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污泥衍生吸附剂对铅离子的吸附机理研究

研究了化学活化法热解制取污泥衍生吸附剂的工艺过程,得出相应工艺条件.利用污泥衍生吸附剂吸附溶液中重金属离子Pb2 ,得到动力学模型.实验结果表明:(1)该吸附过程分为3个阶段:初始阶段(t≤20 min)、过渡阶段(20 min＜t≤30 min)和后期阶段(t＞30 min),满足线性方程dC/dt=kC;(2)该吸附过程的吸附活化能E=26.5 kJ/mol,吸附频率因子A=6900 s-1.整个吸附过程为扩散吸附,吸附传质速度由孔隙扩散阶段和内表面吸附共同控制.     

小型工业煤粉锅炉脱硫技术应用

本文针对未安装脱硫设施的小型煤粉锅炉(20t/h以下)导致SO2排放浓度超标现象,从脱硫效果、工程费用、运行费用等方面对湿式脱硫与干式灰钙法脱硫两种方案进行比较分析,得出采用灰钙法脱硫更为可行。     

Moisture distribution in sludges based on different testing methods

Moisture distributions in municipal sewage sludge, printing and dyeing sludge and paper mill sludge were experimentally studied based on four different methods, i.e., drying test, thermogravimetric-differential thermal analysis (TG-DTA) test, thermogravimetricdifferential scanning calorimetry (TG-DSC) test and water activity test. The results indicated that the moistures in the mechanically dewatered sludges were interstitial water, surface water and bound water. The interstitial water accounted for more than 50% wet basis (wb) of the total moisture content. The bond strength of sludge moisture increased with decreasing moisture content, especially when the moisture content was lower than 50% wb. Furthermore, the comparison among the four different testing methods was presented.The drying test was advantaged by its ability to quantify free water, interstitial water, surface water and bound water; while TG-DSC test, TG-DTA test and water activity test were capable of determining the bond strength of moisture in sludge. It was found that the results from TG-DSC and TG-DTA test are more persuasive than water activity test.     

快辗技术的实验与分析

此文介绍了快辗技术的基本概念及特点,所用的实验设备的参数及实验结果。以及对实验结果的分析。最后就该技术的应用前景及所用设备的较佳参数做了简要的子测及设想。     

Chelator-induced bioextraction of heavy metals from artificially contaminated soil by mushroom (Coprinus comatus)

This study investigated the potential use of chelator-induced bioextraction of heavy metals from soil by Coprinus comatus in a pot experiment. Two production waves of the mushroom were obtained to determine biomass and metal concentration. The application of ethylenediaminetetraacetic acid (EDTA) or nitrilotriacetate (NTA) slightly inhibited the growth of C. comatus, but significantly enhanced the accumulation of heavy metals in fruiting bodies compared with the control. The highest concentrations of Pb, Cu and Cd reached 900.60, 783.61 and 23.64 mg·kg^?1 in a single pot, respectively. However, application of citric acid (CA) had no effect on metal uptake. Moreover, chelators applied to soil after fructification increased the dry biomass and metal concentration in fruiting bodies compared with those applied before sowing mycelia. EDTA was more efficient for inducing metal uptake by C. comatus than NTA or CA, and split applications of EDTA after fructification resulted in the highest total metal uptake by mushroom, i.e. 19.08±2.84, 17.57±0.69 and 0.55±0.06 mg for Pb, Cu and Cd, respectively, which were 130, 12 and 5 times values obtained with the control. Interestingly, many mushrooms turned blue after soil had been treated with chelator, indicating that these mushrooms are rich in Cu.     

挥发性有机物处理新技术的研究

随着VOCs处理要求的不断提高,新型的VOCs处理技术日益受到关注。详细分析了生物法、光催化氧化法以及等离子体催化氧化法VOCs处理新技术的研究进展。高效微生物的筛选、新型生物填充材料的研究使生物法VOCs处理更加实用;光催化剂的表面改性有助于防止催化剂钝化,保证光催化系统的长期稳定运行;等离子体催化氧化VOCs过程中能耗的降低以及副产物的控制将是下一步研究的重点。     

直流电晕自由基簇射治理甲苯的试验研究

利用直流电晕自由基簇射对甲苯有机废气进行试验,分别考察了有机污染物浓度、温度、电压、湿度和停留趑时间等不同因素对去除率的影响.试验结果表明,降低气体温度和一定的湿度能够提高脱除效率,电压增高可以提高脱除效率,停留时间长使得脱除效率升高,但能量效率降低.有机物的浓度增大,会使得脱除效率降低,但同时能提高能量的利用效率.本实验的目的旨在为降解烟气中的多环芳烃(二噁英等)打下基础.