Description of adsorption of hydrophobic organic compounds on sediment using multi-component adsorption model

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食品垃圾好氧降解过程中挥发性有机物(VOCs)排放特征

采用实验室模拟方法,研究了混合食品垃圾(FW)及以橙子、生菜、土豆和西红柿为代表的4种植物性易降解有机垃圾组分好氧降解过程中排放出来的117种挥发性有机物(VOCs)的排放量和组成特征.结果表明,混合食品垃圾好氧降解过程中VOCs总排放量为951.80mg·kg-1,主要为有机硫、含氧化合物和萜烯,分别占VOCs总排放量的43.1%、53.3%和2.1%.橙子、生菜、土豆和西红柿4种植物性易降解有机垃圾好氧降解过程中VOCs的总排放量分别为12736.72、118.67、57.40和228.08mg·kg-1,主要成分均为含氧化合物和萜烯;含氧化合物分别占橙子、生菜、土豆和西红柿4种植物性易降解有机垃圾VOCs总排放量的13.5%、80.9%、85.9%和79.5%,萜烯分别占4种植物性易降解有机垃圾VOCs总排放量的86.5%、16.6%、8.2%和15.6%.     

Potential applications of porous organic polymers as adsorbent for the adsorption of volatile organic compounds

Volatile organic compounds (VOCs) with high toxicity and carcinogenicity are emitted from kinds of industries, which endanger human health and the environment. Adsorption is a promising method for the treatment of VOCs due to its low cost and high efficiency. In recent years, activated carbons, zeolites, and mesoporous materials are widely used to remove VOCs because of their high specific surface area and abundant porosity. However, the hydrophilic nature and low desorption rate of those materials limit their commercial application. Furthermore, the adsorption capacities of VOCs still need to be improved. Porous organic polymers (POPs) with extremely high porosity, structural diversity, and hydrophobic have been considered as one of the most promising candidates for VOCs adsorption. This review generalized the superiority of POPs for VOCs adsorption compared to other porous materials and summarized the studies of VOCs adsorption on different types of POPs. Moreover, the mechanism of competitive adsorption between water and VOCs on the POPs was discussed. Finally, a concise outlook for utilizing POPs for VOCs adsorption was discussed, noting areas in which further work is needed to develop the next-generation POPs for practical applications.     

两种介孔分子筛动态吸附VOCs的研究

采用模板剂法制备了孔道规整、大比表面积的2种介孔分子筛MCM-41和SBA-15,并以甲苯、二甲苯、三甲苯为吸附对象,考察了介孔分子筛动态吸附VOCs的性能.结果表明,增加VOCs分子尺寸和浓度,降低床层温度可大幅提高介孔分子筛吸附性能.SBA-15由于介孔壁上的微孔结构适合吸附低浓度、小分子VOCs;MCM-41更适合吸附高浓度、大分子VOCs.TPD脱附试验表明,VOCs在介孔材料表面150℃下就能基本脱附完全.     

水中微量有机物氯化物脱除复合膜的研制

采用溶液聚合法合成了丙烯酸及丙烯酸酯共聚物，并利用该共聚物可与环氧树脂交联的作用制备出交联聚丙烯酸及基酯的共聚物，并在聚砚底膜上涂膜形成可优先透过氯化有机物（THMs)的复合膜，以1，1，2－三氯乙烷，三氯乙烯等稀水溶液对丙烯酸酯系列复合膜进行了系统测试和研究，分别考察了不同制膜液、交联剂、操作压力、操作温度、进料液浓度、不同分离体系等条件对膜性能的影响，并优选出交联AB－AA－MAA／PS复合膜，表明效果良好，有很好的研究和发展前景。     

Measurement of in-vehicle volatile organic compounds under static conditions

The types and quantities of volatile organic compounds (VOCs) inside vehicles have been determined in one new vehicle and two old vehicles under static conditions using the Thermodesorber-Gas Chromatograph/Mass Spectrometer (TD-GC/MS).Air sampling and analysis was conducted under the requirement of USEPA Method TO-17.A room-size,environment test chamber was utilized to provide stable and accurate control of the required environmental conditions (temperature,humidity,horizontal and vertical airflow velocity,and background VOCs concentration).Static vehicle testing demonstrated that although the amount of total volatile organic compounds (TVOC) detected within each vehicle was relatively distinct (4940μg/m~3 in the new vehicle A,1240μg/m~3 in used vehicle B,and 132μg/m~3 in used vehicle C),toluene,xylene,some aromatic compounds,and various C_7-C_(12) alkanes were among the predominant VOC species in all three vehicles tested.In addition,tetramethyl succinonitrile,possibly derived from foam cushions was detected in vehicle B.The types and quantities of VOCs varied considerably according to various kinds of factors,such as,vehicle age, vehicle model,temperature,air exchange rate,and environment airflow velocity.For example,if the airflow velocity increases from 0.1 m/s to 0.7 m/s,the vehicle's air exchange rate increases from 0.15 h~(-1) to 0.67 h~(-1),and in-vehicle TVOC concentration decreases from 1780 to 1201μg/m~3.     

Emission of oxygenated volatile organic compounds (OVOCs) during the aerobic decomposition of orange wastes

Oxygenated volatile organic compounds(OVOCs) emitted from orange wastes during aerobic decomposition were investigated in a laboratory-controlled incubator for a period of two months. Emission of total OVOCs(TOVOCs) from orange wastes reached 1714 mg/dry kg(330 mg/wet kg). Ethanol, methanol, ethyl acetate, methyl acetate, 2-butanone and acetaldehyde were the most abundant OVOC species with shares of 26.9%, 24.8%, 20.3%, 13.9%, 2.8%and 2.5%, respectively, in the TOVOCs released. The emission fluxes of the above top five OVOCs were quite trivial in the beginning but increased sharply to form one "peak emission window" with maximums at days 1–8 until leveling off after 10 days. This type of "peak emission window" was synchronized with the CO2 fluxes and incubation temperature of the orange wastes, indicating that released OVOCs were mainly derived from secondary metabolites of orange substrates through biotic processes rather than abiotic processes or primary volatilization of the inherent pool in oranges. Acetaldehyde instead had emission fluxes decreasing sharply from its initial maximum to nearly zero in about four days,suggesting that it was inherent rather than secondarily formed. For TOVOCs or all OVOC species except 2-butanone and acetone, over 80% of their emissions occurred during the first week, implying that organic wastes might give off a considerable amount of OVOCs during the early disposal period under aerobic conditions.     

催化剂强化脉冲放电治理有机废气

为增强对有机废气治理的有效性,本文研究了以催化剂协助脉冲放电的新方法对放电条件下的催化技术进行实验研究．结果表明,Mn、Fe等金属氧化物在放电作用下对有机物的降解有较好的催化活性,二者可使甲苯的去除率由59％分别提高到86％和83％;以陶瓷材料为载体用浸渍法制备的催化剂活性及稳定性较好;考察了反应器的结构、电压峰值Vp和催化剂的制各条件对催化效果的影响以及催化剂对不同有机物降解的促进作用     

大气中挥发性有机物(VOCs)对二次有机气溶胶(SOA)生成贡献的参数化估算

大气中二次有机气溶胶(SOA)是PM25中的重要组成部分,挥发性有机物(VOCs)的光化学氧化是其主要来源之一.从VOCs转化生成SOA的过程非常复杂,参数化方法是一种相对简化的估算方式,可以用于区分不同VOCs物种对SOA生成的贡献.本文介绍了基于二产物和基于挥发性分级两种常用的参数化估算方法,并总结分析文献报道的SOA估算结果.文章中也指出现在的参数化估算还存在一些问题,如何准确量化VOCs向SOA的转化过程将是大气化学未来的重要研究工作.     

MO_x-CeO_2/HZSM-5催化剂催化氧化含氯挥发性有机物研究

采用浸渍法制备了不同过渡金属掺杂的MOx-CeO2/HZSM-5（M分别表示Cr、Mn、Fe、Co、Ni和Cu）催化剂,研究了各催化剂对1,2-二氯乙烷（DCE）的催化降解性能.结果表明,过渡金属掺杂后,MOx-12%CeO2/HZSM-5催化剂催化氧化1,2-二氯乙烷（DCE）的活性明显提高.各催化剂（记为M-CeO...     

广州大田山垃圾填埋场空气中微量挥发有机污染物组成

以广州大田山垃圾填埋场为例，研究了在不同季节填埋场空气中微量挥发性有机污染物的种类和含量变化情况。结果表明，在春、夏季样品中可分别检测出47和64种化合物，其中有些化合物为USEPA优先控制毒害有机污染物；夏季样品中微量挥发性有机污染物的浓度大多比春季样品高，有的甚至高1个数量级以上。因此加强对垃圾的卫生填埋，尤其是加强对夏季的垃圾卫生填埋的科学管理，减少挥发性有机污染物向大气中的扩散，应给予充分的关注。     

中国室内挥发性有机物污染特征

近年来室内空气污染问题频发,已引起全社会的广泛关注.挥发性有机物(volatile organic compounds,VOCs)是室内空气的主要污染物之一,其成分复杂,来源广泛,严重威胁人体健康.本文综述了中国近十年来室内VOCs在来源、浓度水平、影响因素及健康评价方面的研究进展.研究表明,室内建筑装修材料、人类活动及室外污染等来源都会影响VOCs的室内浓度;中国住宅内甲醛、苯等VOCs污染普遍存在,家具市场是甲醛污染最高的公共场所;VOCs浓度受到温湿度、通风和装修时间等因素影响;中国室内部分VOCs对人体健康影响评估值超过美国环保署可接受水平.调查更全面的室内VOCs数据,探索对各类因素影响机制,提出更有效降低VOCs对人体健康影响的措施将是未来室内空气治理重点发展方向.     

上海某垃圾填埋场作业区挥发性有机物变化特征及除臭影响

上海某垃圾填埋场填埋量大,垃圾成分环境风险高,亟需对其释放的挥发性有机物(VOCs)变化特征及相关控制方法进行深入研究。采用GC-MS测定不同季节填埋场释放的VOCs各组分浓度,对比喷洒除臭剂对VOCs的影响,并评估其环境及健康风险,以判断不同季节VOCs的首要控制污染物、臭氧生成关键污染物以及表征职业暴露风险,以期为后续有针对性地控制和去除VOCs提供技术支撑。结果表明:VOCs总浓度夏季最高,以烷烃类和醛酮类为主,其中异戊烷、丙酮是优势化合物;除臭剂对臭气、NH₃、H₂S有一定去除效果,但增加了填埋场VOCs的种类和浓度、臭氧生成潜势、非致癌风险与致癌风险,但都在可接受范围内。     

京津冀天然源挥发性有机物排放研究

为探明2017年京津冀地区天然源挥发性有机物(BVOCs)的空间分布,将研究区划分成3 km分辨率的格网,并通过WRF模型提供气象驱动数据,MODIS影像提供植被功能类型和叶面积指数,最终利用MEGAN模型进行模拟研究.结果表明,该模型将BVOCs分成147个细类,其中主要有异戊二烯、单萜烯41类、半萜烯32类、其他VOC73类.2017年京津冀地区BVOCs排放总量为426.26×10~3 t,四大类别的排放比例依次为29.38%、12.32%、6.24%、52.05%.单萜烯中排放较高的类别是α-蒎烯、β-蒎烯、t-β-罗勒烯,而半萜烯中排放较高的是α-法呢烯和β-石竹烯.整个研究区域内BVOCs排放较高的区域位于北部森林与灌丛分布密集的燕山山脉和西南的太行山山脉,其中主要的城市有承德、北京、张家口、保定、石家庄等.排放量较低的地区为廊坊、衡水、天津等地.本研究通过模型模拟得到了京津冀地区2017年高时空分辨率BVOCs排放清单,同时可为以后的大气环境研究提供基础数据.     

Release of volatile organic compounds during bio-drying of municipal solid waste

Three treatments were tested to investigate the release concentrations of volatile organic compounds (VOCs) during the bio-drying of municipal solid waste (MSW) by the aerobic and combined hydrolytic-aerobic processes. Results showed that VOCs were largely released in the first 4 days of bio-drying and the dominant components were: dimethyl disulfide, dimethyl sulfide, benzene, 2-butanone, limonene and methylene chloride. Thus, the combined hydrolytic-aerobic process was suggested for MSW bio-drying due to fewer aeration quantities in this phase when compared with the aerobic process, and the treatment strategies should base on the key properties of these prominent components. Malodorous sulfur compounds and terpenes were mainly released in the early phase of bio-drying, whereas, two peaks of release concentrations appeared for aromatics and ketones during bio-drying. Notably, for the combined hydrolytic-aerobic processes there were also high concentrations of released aromatics in the shift from hydrolytic to aerobic stages. High concentrations of released chlorinateds were observed in the later phase. For the VOCs produced during MSW bio-drying, i.e., malodorous sulfur compounds, terpenes and chlorinateds, their release concentrations were mainly determined by production rates; for the VOCs presented initially in MSW, such as aromatics, their transfer and transport in MSW mainly determined the release concentrations.     

短期干旱胁迫对马尾松排放挥发性有机物的影响

为探究干旱环境对BVOCs排放的影响,应用动态封闭式采样系统和热脱附-气相色谱-飞行质谱仪,对短期干旱胁迫作用下马尾松的BVOCs排放进行了实验室测量,定量分析BVOCs排放速率和排放组成的变化.结果表明,干旱胁迫时异戊二烯的排放受到抑制,排放速率降低约50%;单萜烯和倍半萜烯的排放水平增强,排放速率分别为137.85和0.98μg/(m²·h),是未受胁迫时的2.9和2.0倍.除反式-α-香柠檬烯外,干旱胁迫促进各单萜烯和倍半萜烯化合物的排放,是未受胁迫时的1.3～42.4倍,其中3-蒈烯排放的响应最敏感,α-葑烯、α-水芹烯和石竹烯的响应最弱.干旱胁迫时单萜烯和倍半萜烯的排放组成有所变化,但主导的化合物种类不变,单萜烯以α-蒎烯、香桧烯和β-蒎烯为主,占比分别为48%、17%和17%;倍半萜烯以石竹烯和长叶烯为主,占比分别为57%和34%.     

牛粪燃烧实时排放挥发性有机物特征研究

在实验室模拟青海和西藏2种牛粪在民用炉具中的燃烧过程,采用稀释通道系统与质子转移飞行时间质谱（PTR-TOF-MS）在线分析牛粪燃烧排放的挥发性有机物（VOCs）,通过电子秤实时记录燃料质量的动态变化,获得牛粪燃烧排放VOCs浓度的时间序列与实时排放因子.结果表明,70g牛粪一次燃烧过程持续1100~1500s.牛粪燃烧排放VOCs浓度的时间变化趋势总体上呈单峰分布;西藏牛粪在燃烧450s左右VOCs浓度达到峰值7.92×10^-6;青海牛粪在燃烧400s左右VOCs浓度达到峰值6.01×10^-6.牛粪燃烧VOCs实时排放因子变化范围为40.74~156.88mg/g,趋势不同于VOCs浓度变化,随燃烧过程进行排放因子呈上升趋势.牛粪燃烧至3~4min左右,VOCs排放因子最低.甲醇、甲醛和乙醛3种VOCs排放因子占比最大,其中西藏牛粪燃烧3种VOCs排放占比分别为24.0%±1.9%、11.9%±1.8%和27.4%±1.4%,青海牛粪为22.0%±1.1%、13.3%±2.9%和17.7%±4.6%.本研究首次给出了牛粪燃烧VOCs实时排放因子,可为高时间分辨率排放清单建立和青藏高原地区室内空气污染的健康效应研究提供基础数据.     

廊坊开发区秋季VOCs污染特征及来源解析

使用ZF-PKU-1007大气挥发性有机物（VOCs）在线连续监测系统,于2018年09月25日~10月18日在廊坊市经济技术开发区对99种VOCs进行了在线连续观测.结果显示,观测期间VOCs浓度为69.56×10^-9,烷烃、烯烃、芳香烃、醛酮类及卤代烃体积分数占VOCs比例分别为53.2%、5.9%、7.6%、10.5%和19.3%;使用OH消耗速率L_OH和臭氧生成潜势（OFP）估算了观测期间VOCs大气化学反应活性,结果表明醛酮类、芳香烃和烯烃是主要的活性物质;使用气溶胶生成系数法（FAC）估算了VOCs对二次有机气溶胶（SOA）的贡献,得出VOCs对SOA浓度的贡献值为1.13μg/m³,其中芳香烃对SOA生成贡献占比为94.3%,间/对-二甲苯、甲苯为优势物种;使用PMF模型对VOCs进行了来源解析,识别了5个主要来源,分别为溶剂使用及挥发源（39.6%）、机动车源（22.5%）、固定燃烧源（17.6%）、石化工业源（11.1%）及植物排放源（9.4%）,因此,溶剂使用及挥发源、机动车源及燃烧源应为廊坊开发区秋季大气VOCs控制的重点.     

上海秋季大气挥发性有机物特征及污染物来源分析

综合分析了上海地区秋季典型月份挥发性有机物(VOCs)及其他痕量气体的污染水平及特征,VOCs平均小时浓度为63.64′10-9,非甲烷碳氢化合物(NMHCs)占挥发性有机物总量的67.43%;通过对VOCs物种浓度及特征比值分析发现研究区域大气老化现象明显;结合区域后向气流轨迹分析,考察了不同来源气流对区域污染特征的影响,发现陆地传输气流乙烷/乙炔(E/E)值较海上传输气流低,而两者的苯/甲苯(B/T)值没有明显差异.     

白塔堡河中致嗅类挥发性有机硫化物污染现状及来源研究

为研究白塔堡河中致嗅类挥发性有机硫化物(VOSC)的污染现状及来源,采用吹扫捕集(P&T)与气相色谱(GC)/火焰光度检测器(FPD)联用的分析方法同时测定水体中14种致嗅类VOSC的浓度,并依据综合营养状态指数(TLI)对白塔堡河的富营养化程度进行评价,用主成分分析法(PCA)分析其污染来源.结果表明,所调查的31个点位中,各目标化合物均有不同程度的检出,浓度范围为0~35.98 μg·L^-1;甲硫醚(DMS)为最主要的污染物,其均值为3.36 μg·L^-1,检出率为100%,变异系数为2.30.河流整体处于中度富营养化水平,其中,城市段水体重度富营养化,农村段和城镇段VOSC浓度与TLI显著相关(r>0.70).14种致嗅类VOSC的污染来源可由3个主成分来反映:第一主成分(硫醇类、DMS、甲乙硫醚(EMS))代表由微生物厌氧分解造成的二次污染,其贡献率为44.42%,这是水体富营养化和生活污水、含蛋白质的工业废水及养殖废水排放共同作用的结果;第二主成分(乙硫醚(DES)、二乙基二硫醚(DEDS)、甲丙二硫醚(MPDS)、1-丙基二硫醚(1-PrDS))代表农业面源,贡献率为30.77%;第三主成分(二甲基三硫醚(DMTS))代表工业源,贡献率为7.83%.