2015—2021年广州市臭氧和PM2.5复合污染特征及天气分型研究

利用广州市2015—2021年的地面观测资料和ERA5再分析数据集,统计了臭氧和PM_2.5的时间分布特征及两者同时出现高值(“双高”过程)的气象成因,并进一步用自组织神经网络(SOM)研究了高浓度臭氧和PM_2.5(浓度大于年第85分位数)对应的客观天气型.结果表明,2015—2021年,广州市臭氧浓度呈逐年上升趋势,而PM_2.5浓度则呈逐年下降趋势,臭氧逐渐取代PM_2.5成为首要污染物.“双高”日主要集中在春季和秋季,且秋季占比超过50%.当温度为20～30℃,湿度为30%～50%时,“双高”日出现的概率达到30%以上.基于天气分型方法,本研究发现在所有“双高”污染过程中,主要天气分型依次为：高压底后部型、变性高压脊型、副高+台风外围型、冷锋前部型;秋季发生“双高”污染时,天气分型依次为：副高+台风外围型和副高+弱冷高压脊型.     

广州暖季夜间臭氧增加事件的特征及一次水平输送个例分析

近年来,我国粤港澳大湾区臭氧污染问题日益突出,夜间臭氧浓度呈增长趋势.目前,大部分研究主要关注于白天臭氧的生成过程,而对夜间臭氧浓度不降反升现象的认识明显不足.本研究利用2014—2019年粤港澳大湾区中心城市广州的污染物观测数据,统计了夜间臭氧出现增加(NOE:nocturnal ozone enhancement,定义为夜间20:00—6:00臭氧相邻时刻增加量大于5×10^-9 (Part per billion,下同))的频率、出现时间、峰值浓度,结合ERA5再分析数据和常规气象观测数据分析了NOE事件的潜在成因及垂直和水平输送的相对贡献大小.结果表明,广州暖季(4—11月)夜间出现NOE事件的年平均天数为(59±11) d,主要发生于23:00—3:00.NOE事件造成的夜间峰值浓度可达到(33±10)×10^-9,明显高于不出现夜间臭氧增加(NNOE:non-enhanced nocturnal ozone,定义为夜间20:00—6:00臭氧相邻时刻增加量均小于1×10^-9)时的浓度((16±12)×10     

餐厨垃圾厌氧处理“碳中和”综合效益评价

为综合评估餐厨垃圾厌氧处理的环境影响与效益,对某餐厨垃圾厌氧处理工艺及其技术单元进行生命周期环境影响评价,并建立“碳中和”计算模型预测与验证实际碳排及耗能情况,综合“环境影响-碳排耗能-经济效益-社会效益”对实际案例进行评估.结果表明,沼肥加工和沼气提纯技术单元分别造成39%和59%总环境影响.另外,粗油提炼、沼气提纯以生物基产品回收形式大幅度削减碳排,分别占理论碳削减的9.7%和54.7%.餐厨垃圾处理厂需通过增加系统稳定性、完善气体监测体系、提高技术处理效率和优化设备额外耗能情况等方式,以减少理论与实际碳排能耗偏差.经综合评价,该餐厨垃圾处理厂模式具备实现“负碳”潜力,其工艺推广具有未来前景.     

从剩余污泥厌氧发酵上清液中以鸟粪石形式回收磷

为了实现以鸟粪石(MAP,MgNH4PO4·6H2O)的形式回收剩余污泥厌氧发酵上清液中的氮磷,研究了氮磷溶出的最佳条件及不同的反应条件对氮磷回收的影响.结果表明在p H为10. 5,温度为35℃时,发酵液中溶出的氨氮与正磷酸盐质量浓度皆在第5 d达到峰值;在添加磷源的条件下,磷回收的最佳条件为p H=9. 5、N∶P=0. 8、Mg∶P=1. 8;未添加磷源的条件下,回收磷的最佳条件为p H=9. 5、Mg∶P=1. 6、转速200 r·min-1.此外,降低N∶P摩尔比对于鸟粪石的形态和纯度均有显著影响.利用扫描电镜(SEM)、X光微区分析(EDS)、X射线衍射(XRD)和傅里叶红外光谱(FTIR)等手段对回收产物进行了表面相貌及物相组成分析,证实了沉淀物的主要成分为MAP.以鸟粪石形式回收剩余污泥中的氮磷,是实现污泥资源化的一种有效手段.     

Review on recent progress in on-line monitoring technology for atmospheric pollution source emissions in China

Emissions from mobile sources and stationary sources contribute to atmospheric pollution in China, and its components, which include ultrafine particles (UFPs), volatile organic compounds (VOCs), and other reactive gases, such as NH₃ and NO_x, are the most harmful to human health. China has released various regulations and standards to address pollution from mobile and stationary sources. Thus, it is urgent to develop online monitoring technology for atmospheric pollution source emissions. This study provides an overview of the main progress in mobile and stationary source monitoring technology in China and describes the comprehensive application of some typical instruments in vital areas in recent years. These instruments have been applied to monitor emissions from motor vehicles, ships, airports, the chemical industry, and electric power generation. Not only has the level of atmospheric environment monitoring technology and equipment been improving, but relevant regulations and standards have also been constantly updated. Meanwhile, the developed instruments can provide scientific assistance for the successful implementation of regulations. According to the potential problem areas in atmospheric pollution in China, some research hotspots and future trends of atmospheric online monitoring technology are summarized. Furthermore, more advanced atmospheric online monitoring technology will contribute to a comprehensive understanding of atmospheric pollution and improve environmental monitoring capacity.     

耐蚀高熵合金在岛礁装备中的应用前景

详细综述了南沙岛礁环境下装备的腐蚀特点以及耐蚀高熵合金的研究进展,着重分析了合金化元素及热处理工艺对耐蚀高熵合金腐蚀性能的影响规律.最终,归纳了耐蚀高熵合金在岛礁装备中的潜在应用领域,为全面提升我国关键装备在南沙岛礁环境中的服役能力提供了理论指导.     

铁-碳微电解/改进硫化钠沉淀法处理综合电镀废水

综合电镀废水中含有多种有害的重金属离子,其有效处理是备受关注的问题之一.本文采用铁-碳微电解/改进硫化钠沉淀法处理综合电镀废水,研究Fe/C摩尔比、Na2 S投加量以及废水最终pH对残余重金属离子含量的影响.结果表明,当Fe/C摩尔比为1:1.14,Na2 S投加量为0.29 g/L,最终pH为7.0时,在常温下反应15 min后静置,上清液中残余Cd2+、Zn2+、Ni2+、Cu2+的质量浓度都大幅降低,各种重金属离子的去除率分别为Cd2+90.3％、Zn2+84.2％、Ni2+94.3％和Cu2+96.0％,铁-碳微电解/改进硫化钠沉淀法可有效去除综合电镀废水中的Cd2+、Zn2+、Ni2+、Cu2+等重金属离子.     

Graphitic carbon nitride/biochar composite synthesized by a facile ball-milling method for the adsorption and photocatalytic degradation of enrofloxacin

In order to enhance the removal performance of graphitic carbon nitride (g-C₃N₄) on organic pollutant, a simultaneous process of adsorption and photocatalysis was achieved via the compounding of biochar and g-C₃N₄. In this study, g-C₃N₄ was obtained by a condensation reaction of melamine at 550°C. Then the g-C₃N₄/biochar composites were synthesized by ball milling biochar and g-C₃N₄ together, which was considered as a simple, economical, and green strategy. The characterization of resulting g-C₃N₄/biochar suggested that biochar and g-C₃N₄ achieved effective linkage. The adsorption and photocatalytic performance of the composites were evaluated with enrofloxacin (EFA) as a model pollutant. The result showed that all the g-C₃N₄/biochar composites displayed higher adsorption and photocatalytic performance to EFA than that of pure g-C₃N₄. The 50% g-C₃N₄/biochar performed best and removed 45.2% and 81.1% of EFA (10 mg/L) under darkness and light with a dosage of 1 mg/mL, while g-C₃N₄ were 19.0% and 27.3%, respectively. Besides, 50% g-C₃N₄/biochar showed the highest total organic carbon (TOC) removal efficiency (65.9%). Radical trapping experiments suggested that superoxide radical (?O₂^?) and hole (h⁺) were the main active species in the photocatalytic process. After 4 cycles, the composite still exhibited activity for catalytic removal of EFA.     

Rapid field testing of mercury pollution by designed fluorescent biosensor and its cells-alginate hydrogel-based paper assay

With increasing industrial activities, mercury has been largely discharged into environment and caused serious environmental problems. The growing level of mercury pollution has become a huge threat to human health due to its significant biotoxicity. Therefore, the simple and fast means for on-site monitoring discharged mercury pollution are highly necessary to protect human beings from its pernicious effects in time. Herein, a “turn off” fluorescent biosensor (mCherry L199C) for sensing Hg²⁺ was successfully designed based on direct modification of the chromophore environment of fluorescent protein mCherry. For rapid screening and characterization, the designed variant of mCherry (mCherry L199C) was directly expressed on outer-membrane of  Escherichia coli cells by cell surface display technique. The fluorescent biosensor was characterized to have favorable response to Hg²⁺ at micromole level among other metal ions and over a broad pH range. Further, the cells of the fluorescent biosensor were encapsulated in alginate hydrogel to develop the cells-alginate hydrogel-based paper. The cells-alginate hydrogel-based paper could detect mercury pollution in 5 min with simple operation process and inexpensive equipment, and it could keep fluorescence and activity stable at 4?°C for 24 hr, which would be a high-throughput screening tool in preliminarily reporting the presence of mercury pollution in natural setting.     

石化企业气体泄漏红外成像检测技术研究进展

介绍了气体泄漏红外成像检测技术的工作原理和分类,综述了国内外相关单位的研究进展,重点分析了国外公司对被动式红外成像检测技术的研究情况,并对技术的发展方向进行了展望。