炼油厂废水处理设施及工艺述评

为了弄清目前炼油厂废水的处理水平,通过对三个典型炼油废水处理厂的调查,分别对其处理流程、处理效果、采用的主要处理药剂及处理工艺进行了介绍,分析了每套处理设施的长处以及与先进设施对比存在的不足。     

2008～2018年武汉市BC气溶胶时间演变特征及其来源分析

黑碳(BC)作为最重要的吸收性气溶胶,其辐射强迫显著地改变大气边界层结构和近地面大气污染物的累积。基于2008～2018年武汉市BC和气象要素的观测数据,结合CWT潜在来源模型,分析了BC的时间演变特征和潜在来源分布。结果表明武汉BC平均质量浓度为6 926.4±4 090.6 ng/m³,?ngstr9m指数(AAE)和液体燃料源对BC贡献占比(P)的平均值分别为0.98±0.44和76.6%,BC主要来自液体燃料的燃烧。2014～2017年BC质量浓度呈现显著的下降趋势,液体燃料对BC的贡献逐年增加。BC的季节分布为冬季(8 537.3 ng/m³)>春季(7 513.2 ng/m³)>秋季(6 820.2 ng/m³)>夏季(6 161.9 ng/m³),BC_liquid占比为秋季(80.0%)>冬季(77.3%)>春季(76.2%)>夏季(72.9%)。不同季节BC日变化特征不同。四个季节BC日变化在2008～2...     

考虑绕行效应的人员疏散元胞自动机模型研究

在传统的元胞自动机疏散模型中,行人只考虑临近的4个网格状态以做出运动决策,而在实际疏散过程中,每个人会从更大的感知范围内收集信息,并会主动避开障碍物,从而选择更合理的路径。针对此问题,建立考虑绕行行为的元胞自动机模型（DCA模型）,模型引入行人感知范围参数,用于反映行人对障碍物的反应程度或绕行倾向;通过建立单门疏散场景,研究绕行效应对疏散的影响。研究结果表明:考虑绕行效应时,行人能够更好地绕过障碍物,在出口前形成典型的拱形聚集形态;感知范围越大,拱形聚集形态形成的越快;通过将DCA模型与经典的无后退的有偏随机行走模型和场域模型分别进行比较,DCA模型可以减少不必要和不合理的后退运动行为,这与实际更为一致。     

西安市秋季灰霾天气微生物气溶胶的特性研究

为探明西安市秋季灰霾天气条件下微生物气溶胶的特性,于2014年10月7日到23日两次灰霾过程期间,在西安市长安大学站点,采用Andersen六级撞击式空气采样器对细菌与真菌气溶胶进行采样,并对其浓度、粒径、种属分布及其与气象因素的相关关系进行详细分析.结果表明,在灰霾天期间,可培养细菌与真菌气溶胶的浓度水平分别为1102~1737 CFU·m-~3和1466~1704 CFU·m-~3,不仅远高于非灰霾天微生物气溶胶的浓度值,也超过了中国科学院推荐的标准值.在非灰霾天气条件下,空气中大部分可培养细菌气溶胶(79.7%)与真菌气溶胶(74.6%)均分布在粗颗粒范围(2.1μm),它们的中位径(NMD)分别为(2.32±0.12)μm、(2.48±0.24)μm;而在灰霾天气条件下,可培养细菌气溶胶与真菌气溶胶的中位径分别为(1.96±0.29)μm和(2.44±0.23)μm.此外,在灰霾天期间,空气中优势细菌除了葡萄球菌属(Micrococcus)与微球菌属(Staphylococcus)外,还鉴定出了非霾天没有检测出的致病菌种奈瑟氏菌属(Neisseria);而真菌在灰霾天时,除了曲霉属(Aspergillus)检出频率大幅提高外,还出现了非霾天未鉴定出的致病菌属拟青霉属(Paecilomyces)与头孢霉属(Cephalosporium).研究表明,相比于非灰霾天气,灰霾天气下有更高的微生物气溶胶暴露风险.研究结果可以为评估灰霾暴发时微生物气溶胶引起的环境与健康效应提供基础数据.     

Characterization of the aerosol chemical composition during the COVID-19 lockdown period in Suzhou in the Yangtze River Delta, China

To control the spread of COVID-19, rigorous restrictions have been implemented in China, resulting in a great reduction in pollutant emissions. In this study, we evaluated the air quality in the Yangtze River Delta during the COVID-19 lockdown period using satellite and ground-based data, including particle matter (PM), trace gases, water-soluble ions (WSIs) and black carbon (BC). We found that the impacts of lockdown policy on air quality cannot be accurately assessed using MODIS aerosol optical depth (AOD) data, whereas the tropospheric nitrogen dioxide (NO₂) vertical column density can well reflect the influences of these restrictions on human activities. Compared to the pre-COVID period, the PM_2.5, PM₁₀, NO₂, carbon monoxide (CO), BC and WSIs during the lockdown in Suzhou were observed to decrease by 37.2%, 38.3%, 64.5%, 26.1%, 53.3% and 58.6%, respectively, while the sulfur dioxide (SO₂) and ozone (O₃) increased by 1.5% and 104.7%. The WSIs ranked in the order of NO₃^? > NH₄⁺ > SO₄^2- > Cl^? > Ca²⁺ > K⁺ > Mg²⁺ > Na⁺ during the lockdown period. By comparisons with the ion concentrations during the pre-COVID period, we found that the ions NO₃^?, NH₄⁺, SO₄^2?, Cl^?, Ca²⁺, K⁺ and Na⁺ decreased by 66.3%, 48.8%, 52.9%, 56.9%, 57.9% and 76.3%, respectively, during the lockdown, in contrast to Mg²⁺, which increased by 30.2%. The lockdown policy was found to have great impacts on the diurnal variations of Cl^?, SO₄^2?, Na⁺ and Ca²⁺.     

油气田开发对湿地的影响及保护措施

湿地环境和生态系统的保护及合理利用，在当今国际已普遍受到重视。我国石油勘探开发活动对湿地的影响，大体可分为直接和间接两类。直接影响主要由污染物排放；机械和人类活动对野生动植物的影响；油田设施占用地面；围湖或围海等构成。间接影响主要指影响湿地的水文条件及油气田开发带动其它资源的开发和当地经济的发展。为了减少油气田开发对湿地不利的影响，编制了《中国石油天然气总公司湿地保护行动计划》，建立了湿地保护的专门管理机构，并进而采取了一系列保护措施。     

Characteristics and sources of WSI in North China Plain: A simultaneous measurement at the summit and foot of Mount Tai

To better understand the characteristics and sources of water soluble ions (WSI) in North China Plain (NCP), fine particles (PM_2.5) were simultaneously sampled at the summit (SM) and foot (FT) of Mount Tai during May 12th to June 24th, 2017. Ion chromatography analysis showed that concentration of WSI was lower at SM (22.26 ± 16.53 μg/m³) than that at FT (31.02 ± 21.92 μg/m³). The concentration and proportion of SO₄^2? in total WSI were both lower than the values reported in previous studies. Daytime WSI concentrations were higher than that at nighttime at SM, while the opposite results were obtained at FT, possibly associated with more anthropogenic activities and higher boundary layer height (BLH) during daytimes. A severe pollution event occurred during June 14th – June 16th was documented at both FT and SM. Regional transport and topography-forced vertical transport along the slope of the mountain could explain the higher concentrations of pollutants at SM. The analyses also indicated that NH₄⁺ existed mainly in the form of NH₄HSO₄ and NH₄NO₃, but (NH₄)₂SO₄ could also exist, especially when emissions of NH₄⁺ and NH₃ were increased during daytime at FT. The results of principal component analysis (PCA) illustrated that secondary aerosols, coal/biomass burnings, sea-salts and crustal/soil dusts were the main sources at SM, and secondary aerosols and crustal/soil dusts contributed most at FT. Backward air-mass trajectories were classified into four clusters, of which air masses with the highest frequency and WSI concentrations were originated from the southwest with secondary ions (SO₄^2-, NO₃^- and NH₄⁺) as major pollutants.     

污水中溶解游离氨基酸和结合氨基酸测定方法研究

采用邻苯二甲醛作为柱前衍生化试剂,结合反相高效液相色谱,对污水中溶解游离氨基酸（dissolvedfreeami．nOacid,DFAA）进行定性和定量分析,探讨了污水样品有无前处理对DFAA分析的影响,并采用气相酸水解方法对污水中总溶解氨基酸（dissolvedtotalaminoacid,DTAA）进行了分析。结果表明,污水经过pH调节和N,流清洗后,可以明显去除氨和挥发性胺的干扰,色谱峰更加清晰;前处理后的水样经RP—HPLC分析,能够快速检测出14种氨基酸,各氨基酸在一定线性范围内呈现良好的线性关系,相应的线性相关系数（R^2）均大于0．99,加标回收率为92％～102％。污水处理厂进水和出水中氨基酸主要以溶解结合氨基酸（dissolvedcombinedaminoacid,DCAA）为主,与进水相比,出水中DFAA含量减少了0．22μmol／L,DTAA由5．68μmol／L降至3．08μmol／L。     

好氧堆肥反应器对人粪便堆肥中温降解的中试研究

控制温度为（35±2）℃,以新鲜锯末为空白载体,在控制含水率为55%~60%和强制通风的好氧条件下,进行为期15 d的实验,进行了人粪便好氧堆肥的中试研究,重点分析了在堆肥过程中有机物的降解、氮素的迁移转化规律及生物量的变化。结果表明,粪便中有机物含量在前2天稍微上升,然后迅速下降,最终去除率为71.82%;随着NH₃-N释放量的增加,堆料中N_tot含量从第4天开始减少,最终损失 22.61%,其中N_org损失占74.35%,NH₃-N占23.52%;所损失的氮素有91.66%以氨氮的形式释放。粪便中的有机物和氮的含量能在8~10 d后达到稳定,且堆体无臭味;粪便中溶解性有机物为微生物的生长提供营养物质,因此生物量变化的过程与有机物降解的有着紧密的联系;病原菌在堆肥过程中得到有效去除,表明该反应器堆肥的无害化。     

Effects of ionic liquid [N4444] AOT on rice seedling growth cytomembrane damage and rhizobacteria resistance

Environmental Science and Pollution Research - Ionic liquids (ILs) are solvents composed of ions, containing a large asymmetric cation with an anion. With increasing and widespread applications,...