Baosteel emission control significantly benefited air quality in Shanghai

As the largest iron and steel producer in China, a part of Baosteel moved out of Shanghai deserves close attention due to its environmental impact. To understand the effect of Baosteel emission control on air quality in Shanghai, daily PM_(10), PM_(2.5), SO_2, NO_2 and CO were measured from 2010 to 2016. Concentrations of pollutants in Baoshan District presented a decreased trend during 2010–2016, with a reduction rate of 28.6% for PM_(10), 67.3% for SO_2, 8.6% for NO_2 and 42.0% for CO. However, fine particle pollution in Baoshan District during 2012–2016 seems to become more prominent, with PM_(2.5) concentration of 47 ± 28,45 ± 33, 38 ± 24, 54 ± 41 and 51 ± 34 μg/m3, respectively, indicating a slight increase of 8.5%in PM_(2.5). Concentrations of PM_(10) and CO decreased by 12.5% and 33.8% in the second half year in 2016(compared with that in 2015) probably due to closure of blast furnace of Baosteel. Baosteel was identified as the largest pollution source in Baoshan District.Emission from Baosteel accounted for 58.0% of SO_2, 43.6% of NO_2 and 79.3% of dust in total emission from Baoshan District during 2010–2015. Meanwhile, pollutant emission and coal consumption from Baosteel decreased by 52.0% for SO_2, 40.1% for NO_2, 15.7% for dust and22% for coal consumption. Energy consumption in Baoshan District reduced by 31% from2011 to 2015. Air quality improvement in Shanghai was attributed to local emission reduction, together with regional air quality improvement.     

汞矿山废弃地土壤汞污染研究

中国是世界上第3大产汞国,而主要的供应源是汞开采,尽管多数矿山开采活动已经关闭,但大规模遗留下来的矿山废弃地会引发许多生态环境问题,尤其是矿山废弃地土壤中汞污染已经成为严重的环境问题之一.文章通过对矿山废弃地的环境污染特征、土壤汞污染途径、迁移方式进行系统综述,介绍了土壤汞污染修复技术,并在此基础上提出了存在的问题以及有待进一步研究的方向.     

循环冷却水高浓缩倍率处理技术在电厂的应用研究

随着淡水资源的日益紧缺,如何提高水资源的利用率以达到节约用水的目的引起更高的关注.基于河南某电厂循环冷却水浓缩倍率仅为2.0的现状,选取两种新型高效的水处理药剂(1号、2号).经试验研究确定处理效果更佳的1号药剂为选择药剂,并确定最佳投药量为8 mg/l.将1号药剂应用到实际工程中,循环水浓缩倍率提高至6.5以上,节省了大量的水资源,同时减少废水的排放量,为该电厂带来了良好的经济和环境效益,也为类似工程的建设提供一定的参考作用.     

Spatial and temporal variation of haze in China from 1961 to 2012

The purpose of this study is to analyze the climatic characteristics and long-term spatial and temporal variations of haze occurrence in China. The impact factors of haze trends are also discussed. Meteorological data from 1961 to 2012 and daily PM₁₀ concentrations from 2003 to 2012 were employed in this study. The results indicate that the annual-average hazy days at all stations have been increasing rapidly from 4 days in 1961 to 18 days in 2012. The maximum number of haze days occur in winter (41.1%) while the minimum occur in summer (10.4%). During 1961-2012, the high occurrence areas of haze shifted from central to south and east regions of China. The Beijing-Tianjin-Hebei (Jing-Jin-Ji) region, Shanxi, Shaanxi, and Henan Province are the high occurrence areas for haze, while the Yangtze River Delta (YRD) and the Pearl River Delta (PRD) have become regions with high haze occurrences in the last 25 years. Temperature and pressure are positively correlated with the number of haze days. However, wind, relative humidity, precipitation, and sunshine duration are negatively correlated with the number of haze days. The key meteorological factors affecting the formation and dissipation of haze vary for high and low altitudes, and are closely related to anthropogenic activities. In recent years, anthropogenic activities have played a more important role in haze occurrences compared with meteorological factors.     

铁碳微电解处理染料污水的影响因素筛选与优化

为提高铁碳微电解处理染料废水中COD_Cr去除率,将Plackett-Burman和Box-Behnken试验设计方法相结合应用于废水处理条件的筛选与优化. Plackett-Burman设计试验结果表明:铁碳比(体积比)、反应时间和曝气量是影响铁碳微电解处理染料废水COD_Cr去除率的3个关键性因素. Box-Behnken试验设计方法和三维响应面分析表明,铁碳微电解处理染料废水对COD_Cr去除率的最优化操作条件是铁碳比为3∶2、反应时间为120 min、曝气量为40 L/min. 在该优化条件下,当ρ(COD_Cr)在1 000~10 000 mg/L之间变化时,COD_Cr去除率的试验结果均落在模型预测结果的95%置信区间(75.5%~83.3%)内,说明模型能对铁碳微电解处理结果进行良好的预测,因此具有一定的可信度.      

2007—2014年北京地区PM2.5质量浓度变化特征

为更好地解析北京地区ρ(PM_2.5)的长期变化特征及气流轨迹聚类分析结果,对2007年8月—2014年7月在中国环境科学研究院实测的ρ(PM_2.5)数据进行了统计分析,分析其年际、季节和月际变化特征;通过计算PM_2.5的AQI分指数,分析了污染等级的时间变化特征;结合后向气流轨迹,对ρ(PM_2.5)年际、季节变化与气团来源的关系进行了分析.结果表明:北京地区2008—2013年ρ(PM_2.5)年均值分别为111.5、95.8、94.8、80.5、75.2、81.3 μg/m3,整体呈逐年下降趋势,但污染水平依然较高;ρ(PM_2.5)由高到低的季节次序为秋季、冬季、春季、夏季,平均值分别为111.6、94.8、77.2、70.5 μg/m3,PM_2.5重污染时段主要出现在秋冬季节,并且冬季ρ(PM_2.5)近年来逐渐呈上升趋势;ρ(PM_2.5)月均值呈单峰型变化,11月最高(为125.3 μg/m3),7月最低(为76.4 μg/m3);轨迹聚类分析发现,途经山西省北部和河北省南部的气流轨迹中ρ(PM_2.5)较高,而来自北方及西北方向的气团相对较清洁,ρ(PM_2.5)较低.北京地区近些年实施的大气污染减排措施对于控制PM_2.5污染取得了一定效果,但针对秋冬季节重污染过程的控制力度仍需要加强,同时也要注意区域污染传输对北京地区ρ(PM_2.5)的影响.      

不饱和季铵盐的合成及其聚合物在化工及环保领域的应用

按不饱和基团的类型对不饱和季铵盐进行了分类,并综述了其合成方法。介绍了其聚合物在含油污水处理、抗菌、纺织品、新材料等领域的应用。阐述了在不饱和季铵盐的开发及其聚合物的应用方面存在的问题。指出了今后的发展方向:应该加大科研投入,加快新型不饱和季铵盐的研发进程,特别是在主结构设计、纯度提高以及新型絮凝剂单体的多样性方面,以制备出多功能性的单体和聚合物。     

1981-2014年四川不同强度霾时空特征及气候成因研究

利用四川156个气象观测站1981-2014年霾日观测资料,对区域内不同强度霾日的时空分布特征及变化趋势进行分析.结果发现：不同强度霾日数呈现轻霾和重霾显著上升、中霾下降的趋势,20世纪90年代后霾日整体偏多,其中,秋、冬季发生频率偏高,12月和1月是多发时段;不同强度年均霾日高值区集中在盆地中部、东部地区,低值区主要位于盆地西南地区,并呈现盆地中北部霾日逐年减少,盆地南部逐年增多的变化趋势.结合季节特征探讨霾日形成机理发现,春、夏季欧亚中高纬度呈现两槽一脊的环流形势,印缅槽较强,利于降水,盆地相对湿度为85%以上,高原东侧上升气流较明显,大气对流层中下层为"上冷下暖"的递减层结,利于大气污染排放物垂直交换及其对外扩散;秋、冬季高纬度以纬向环流为主,经向环流偏弱,冷空气被阻挡在盆地以北以西区域,盆地东部为下沉气流,850 hPa以下的偏东气流使东部污染物向西蔓延,青藏高原以东地区上空为显著的"上暖下冷"逆温层结,相对湿度为80%左右,地面气温增加,相对湿度下降,使霾不易向雾转换,加重霾日高频状况的发生.     

Fe0-PRB去除Cr(Ⅵ)反应动力学及影响机制

零价铁渗透式反应墙技术(zero-valent iron permeable reactive barrier,Fe~0-PRB)是近年来兴起的一项高效经济的地下水原位修复技术,被成功应用于地下水Cr(Ⅵ)污染的场地修复中.针对Fe~0-PRB去除Cr(Ⅵ)的反应影响机制开展研究,从动力学角度揭示零价铁去除Cr(Ⅵ)的环境条件响应规律,获得描述零价铁去除Cr(Ⅵ)的反应动力学模型.考察了地下水常见离子对Cr(Ⅵ)去除的影响,发现地下水中氯离子通过影响电子传递影响Cr(Ⅵ)去除,硫酸根、镁离子通过参与反应影响Cr(Ⅵ)去除,碳酸氢根通过参与反应和影响电子传递共同影响Cr(Ⅵ)去除,钙离子对Cr(Ⅵ)去除影响不大.研究结果为Fe~0-PRB去除Cr(Ⅵ)的工艺参数优化提供方法和理论依据.