Total volatile organic compound concentration and its influencing factors in urban indoor air after decoration

The indoor total volatile organic compound (TVOC) concentrations and their relationship to potential influencing factors were evaluated. Samples (n = 2302) were collected from 2007 to 2009 both in old structures and new construction in the city of Hangzhou from bedrooms, sitting rooms and studies that had been decorated within the previous year. The average TVOC concentration in all the newly decorated rooms was 0.65±0.69 mg/m 3 . 35.8% of samples exceeded the China standard. Over the past 3 years, the TVOC...     

Desorption characteristics of total phosphorus and heavy metals from impervious urban surface sediments

Dry sediments were collected from one roof and two roads in the central area of Beijing. The sediments were dry and wet sieved. The concentrations of total phosphorus (TP) and heavy metals were analyzed. The highest mass proportion of the dry sediments from the roads were between 125 and 300 μm in diameter, while the roof sediments were much smaller, with 75% of the total sediment mass between 40 and 74 μm in diameter. The concentrations of TP and heavy metals in the roof sediments were much higher than in the road sediments. The concentrations of the six heavy metals investigated had a similar order for all three sampling sites, with the Zn concentration always being the highest, followed by the Mn concentration, and the Ni concentration was always the lowest. After wet sieving, 76.9% to 91% of the TP in the sediments from the three sites remained in undesorbable particulate form, and 68.9% to 97% of the heavy metals were present in undesorbable particulate form. The concentrations of undesorbed heavy metals in the roof sediments tended to increase with increasing sediment size, but a similar trend was not found in the road sediments. This study shows that more attention should be given to the particulate matter in stormwater runoff, as reducing the amount of particulates will improve the efficiency of pollution control measures.     

Distribution and partition of polybrominated diphenyl ethers （PBDEs） in water of the Zhujiang River Estuary

The spatial, temporal, and vertical distributions of polybrominated diphenyl ethers （PBDEs） in water columns from the Zhujiang River Estuary were examined, and the partition behavior of PBDEs between particle and dissolved phases was investigated in the present study. The results show that the distributions of PBDEs concentrations in the water varied with the sampling seasons. The PBDEs concentrations in water samples were lower in May 2005, when the brackish water was dominant in the estuary, than in October 2005, when fresh water from river runoff dominated the estuary. The spatial distribution of PBDEs in October 2005 indicated that the river runoff was the major mode to input PBDEs to the estuary, and the concentration of PBDEs in water might be dissolved organic carbon （DOC） dependence. The spatial and vertical distributions of PBDEs in May 2005 were relatively homogeneous, and SPM was the major factor on controlling the levels of PBDEs in this sampling time. Both DOC and POC could play certain roles in determining the distribution and partition of PBDEs between particle and dissolved phases, but their effects varied with the water properties.     

Pb uptake, accumulation, subcellular distribution in a Pb－accumulating ecotype of Sedum alfredii （Hance）

Lead concentrations in roots, stems and leaves of accumulating and non-accumulating ecotypes of Sedum alfredii (Hance) were studied through a hydroponic experiment with different Pb concentrations sup-plied as Pb( NO3 )2 .Lead concentrations in leaves and stems of the accumulating ecotype were 4-9 times and 3-5 times those of the non-accumulating ecotype, and Pb-accumulated amounts in stems and leaves of theaccumulating ecotype were 4-9 times and 8-1l times higher than those of the non-accumulating ecotype,respectively. The results indicated that the accumulating ecotype had better ability to transport Pb from roots toshoots. The subeellular distributions of Pb in the root, stem and leaf tissues were studied using sucrose differ-ential centrifugation. Approximately 50% of Pb contents was found to be associated with the cell wall fractionin stems of the accumulating ecotype and the percentage increased to 80％ both in roots and leaves, no matter when plants were grown with different levels of Pb. The results indicated that the distribution of Pb on cell walls of the accumulating ecotype could mainly account for the high tolerance to Pb.     

Polychlorinated naphthalenes (PCNs) in surface sediments of the Yangtze and Yellow River Estuaries, China

The concentrations and congener profiles of poly-chlorinated naphthalenes (PCNs) in surface sediment samples collected from the Yangtze and Yellow River Estuaries were inves-tigated. PCN congeners (from MoCNs to OCN) were determined by isotope dilution/high-resolution gas chromatography/high-resolution mass spectrometry (HRGC-HRMS). The total concentrations of PCNs were 34.3-303.0 pg/g (dry weight, dw) in the Yangtze Estuary samples and 6.2-408.0 pg/g (dw) in the Yellow River Estuary samples, which were lower compared with that in other sediments reported by previous studies. In addition, the remarkably different homologue or congener profiles of PCNs have been obtained in this study. Samples dominated with MoCNs to TrCNs might be attributed to atmospheric deposition and global fractionation, while in other samples taken from the surrounding industrial areas the enrichment of higher chlorinated homologues suggested that the industrial and human activities should be the main potential sources.     

Concentrations and source identification of organochlorine pesticides (OCPs) in soils from Wolong Natural Reserve

In order to understand the distribution profile, composition characteristics and sources of OCPs, soil samples collected from Wolong Natural Reserve (WNR) in spring and autumn in 2005 were analyzed using gas chromatography coupled with electron capture detector (GC-ECD). Results showed that all OCPs concentrations were in the range of 10?2 ng/g―10?1 ng/g, representing the background level in those remote sites. Generally, their concentrations were slightly higher in spring than in autumn, which could be exp...     

Analysis of mechanical behaviors of big pipe roof for shallow buried large-span tunnel

A series of researches on mechanical behaviors of big pipe roof for shallow large-span loess tunnel were carried out based on the Wenxiang tunnel in Zhengzhou -Xi＇ an Special Passenger Railway. The longitudinal de- formations of the pipe roofs were monitored and the mechanical behaviors of the pipe roofs were analyzed at the test section. A new double-parameter elastic foundation beam model for pipe roof in shallow tunnels was put for- ward in Wenxiang tunnel. The measured values and the calculation results agreed well with each other, revealing the force-deformation law of big pipe roof in loess tunnel： At about 15 m in front of the excavating face, the pipe roof starts to bear the load; at about 15 m behind the excavating face, the force of the pipe roof tends to be stabi- lized; the longitudinal deformation of the whole pipe roofs is groove-shaped distribution, and the largest force of pipe roofs is at the excavating face. Simultaneously, the results also indicate that mechanical behaviors of pipe roof closely relate to the location of the excavation face, the footage of the tunnelling cycle and the mechanics pa- rameters of pipe roof and rock. The conclusions can be reference for the design parameter optimization and the con- struction scheme selection of pipe roofs, and have been verified by the result of numerical analysis software FLAC3D and deformation monitoring.     

Organotin compounds in surface sediments from selected fishing ports along the Chinese coast

The concentrations and species of organotin compounds(OTCs) in 52 surface sediment samples from nine fishing ports along the Chinese coast were studied.Butyltins(BTs) and phenyltins(PhTs) were derivatized using sodium tetraethylborate(NaBEt 4) and determined by head-space solid-phase microextraction(HS-SPME) gas chromatography coupled with a flame photometric detector(GC-FPD).The concentrations of OTCs ranged from <3.6 to 194 ng(Sn) g-1 dry weight(dw) for monobutyltin(MBT),<2.3 to 41.5 ng(Sn) g-1 dw for dibutyltin(DBT),<0.7 to 86.0 ng(Sn) g-1 dw for tributyltin(TBT) and <5.1 to 66.1 ng(Sn) g-1 dw for monophenyltin(MPhT),respectively.The concentrations of diphenyltin(DPhT) and triphenyltin(TPhT) were below the limit of detection(LOD).BTs were the main species in the sediments except for the samples collected from Shazikou fishing port in Qingdao.The concentrations of MBT were higher than DBT and TBT.The concentrations of OTCs in the sediments varied widely among different sampling locations.The concentrations of BTs were much higher in the samples collected from fishing ports close to the South China Sea than those in coast of the East China Sea and the Yellow Sea.MPhT was prevalent in most sampling stations except for those in coast of the East China Sea.The environmental and ecotoxicological risks of TBT in most sediment samples were low.     

Atmospheric nitrous oxide observations above the oceanic surface during CHINARE-18

The gas samples in the marine boundary layer were collected from the track for research ship Xuelong during the 18th Chinese Antarctic Research Expedition (CHINARE-18) and nitrous oxide measurements were made by HP5890ECD-GC in the laboratory. The results represent the shipboard N2O data set obtained within the lower troposphere with the average concentration of (313.5±2.6)nL*L-1 from 31°N to 69°S. The results showed a latitudinally weighted, mean interhemispheric difference of 0.61 nL*L-1. The latitudinal distribution of atmospheric N2O concentration was analyzed from northern midlatitudes to Southern Ocean around the Antarctic continent and it was showed that N2O concentration in the current confluences was higher than that in other oceanic areas. This indicated that strong N2O emissions occurred there. The longitudinal distribution of N2O concentrations in the Southern Ocean also showed similar situation. According to the interhemispheric difference of atmospheric N2O concentrations and the two-box model, we estimated that 2/5 of the global flux of N2O into the atmosphere is derived from the sources in the southern hemisphere.     

Occurrence and assessment of veterinary antibiotics in swine manures: A case study in East China

We investigated the occurrence of 14 selected antibiotics including five therapeutic classes of tetracyclines,sulfonamides,macrolides,fluoroquinolones and chloramphenicols in manures collected from four swine farms of different sizes in eastern China.Tetracyclines(tetracycline,oxytetracycline,chlortetracycline,and doxycycline) and sulfadiazine were the most prominent contaminants in the manure samples,with maximum concentrations reaching 98.2 × 10 3,354.0 × 10 3,139.4 × 10 3,37.2× 10 3,and 7.1× 10 3 μg/kg,respectively.The occurrence of these compounds was dependent on breeding scale,animal type,and breeding season.Manure storage and vermiculture were not able to effectively deplete the heavier contaminants(tetracyclines and sulfadiazine),resulting in high levels of these chemicals remaining in manures.Therefore,the occurrence of these antibiotics in agricultural soils(0.1-205.1 μg/kg) collected from four types of agricultural land(pear orchard,tea plantation,bamboo forest,and paddy field) near the studied farms,was a reflection of manure application.However,the extremely high concentrations of antibiotics in manures were unlikely from feed consumption,but from other direct forms of medicine application.     

赣江水体氮磷营养盐分布特征与污染来源

以2013年1月和6月实测数据为参考,分析赣江水体氨态氮（ NH4+-N）、硝态氮（ NO3--N）和总磷（ TP）分布特征和污染来源。结果表明:赣江水体枯水期的NH4+-N和NO3--N平均质量浓度高于丰水期,但不具有统计学意义;枯水期的TP平均质量浓度显著高于丰水期。 NH4+-N在赣州和南昌市区下游出现极大值;枯水期干流NO3--N质量浓度在赣州和南昌市区下游较高,丰水期干流浓度相差不大,支流中桃江和袁水NO3--N质量浓度明显偏高;枯水期赣江TP质量浓度在赣州市和南昌市下游出现高值区,丰水期只在赣州市下游出现高值区。通过赣江氮磷营养盐的时空分布特征以及与Cl-质量浓度的相关性得出,赣江NH4+-N污染主要来源于城市污水排放;NO3--N在枯水期主要来源于城市污水排放,丰水期则来自农业污水和城市污水的共同作用;TP主要来源于城市污水排放,其次为农业污水影响。     

包膜肥料对水稻土壤渗滤液中NO2--N、NO3--N、NH4+-N的影响

通过有机玻璃土柱盆栽试验,研究了包膜肥料在水稻不同生育期对不同深度土层的土壤渗滤液中NO2--N、NO3--N、NH4+-N含量的影响。结果表明,土壤渗滤液中NO2--N、NO3--N、NH4+-N质量浓度随着水稻的生长逐渐降低;在水稻分蘖期和拔节期,随着土壤深度的增加NO2--N、NO3--N含量呈现先减小后增大的趋势,NH4+-N含量呈现先增大再减小再增大的趋势;在水稻抽穗期和成熟期,NO2--N、NO3--N含量呈现逐渐减小的趋势,NH4+-N含量呈现增大的趋势。在水稻生育期内与施用普通尿素UR相比,包膜肥料LP40、LPSS、SC60氮素渗滤损失总量分别降低了58.27%,46.38%,33.30%。     

三级渗滤系统控制农业径流污染的试验

为明确渗滤系统在控制农业径流污染中的拦截削减性能,在重庆市万州高峰镇鹿山河旁建立三级渗滤系统,开展了农业径流污染净化效果的试验。结果显示,系统对SS、NH4+-N、TN和TP具有较好的去除效果,平均去除率可分别达到80%、78%、37%及48%。污染物浓度沿系统各级逐渐降低,TN、NH4+-N的去除率沿程逐渐趋缓,TP、SS去除率沿程没有明显减缓的趋势。系统第一级对氮的去除以颗粒态为主,第二、三级以溶解态为主;系统第一、二级对磷的去除以颗粒态为主,第三级对颗粒态磷与溶解态磷的去除比例相近。系统第一级对各污染物的去除效率最高,硝化作用较强;第二级TN、NH4+-N的去除率与第一级相比依然较高;第三级NH4+-N、TN、TP去除率较低,但SS的去除效率与第二级相当。     

不同介质组成的粗放型绿色屋面降雨出流水质

构建5个绿色屋面中试设施,考察不同介质组成的设施在实际降雨条件下出水水质状况并与降雨、沥青屋面径流、空白对照设施出水水质进行对比.结果表明,常用屋顶绿化复合介质设施的出流中,TP,NH4+-N和COD的平均质量浓度分别达到0.95,1.66,115mg·L-1,高于沥青屋面径流和空白对照设施的出水水质,使用无机复合介质和废弃物利用介质的设施出水水质优于对照屋面;从出水污染物质量负荷角度分析,使用上述3种类型介质的绿色屋面设施都不是TN,TP,TSS和COD的污染源,并能够减少雨水带来的NH4+-N负荷;绿色屋面设施植被层生长状况和出水中营养物质浓度呈现相关性,长势较好的设施出流中营养物质浓度较高;介质中添加给水厂污泥能够有效控制介质层P的淋失且不影响植物生长.     

惠州大亚湾大气湿沉降中氮营养盐变化特征的研究

通过对降水中氮营养盐质量浓度及其沉降通量变化特征的研究,研究了大气湿沉降中氮营养盐对大亚湾水生生态系统的影响.结果表明,观测期间NH4+-N、NO3--N/NO2--N和TN降雨量加权平均质量浓度分别为0.474、0.536和1.23mg/L,氮质量浓度在8月份出现了明显的峰值;湿沉降通量分别为58.93、78.13和158.75kg/( km2.月),其中无机氮占总氮含量的86.34%,大亚湾大气湿沉降中氮营养盐主要以NO3--N/NO2--N的形式存在.与2009年的观测结果相比较,2012年大气中氮的沉降通量增加了约1倍.通过大气湿沉降输入的氮营养盐在大亚湾水体富营养化过程中产生了重要作用,在研究水体富营养盐问题时应考虑降水的贡献.     

常州市不同下垫面污染物冲刷特征

为研究城市硬化下垫面降雨径流对污染物的冲刷特征, 选取常州市5类典型硬化下垫面, 采样监测2015年3-8月期间6场降雨径流及污染物浓度变化过程, 得到以下结果。1) 地面径流污染物EMC均值高于屋面径流; 地面径流SS和COD浓度超过水质标准Ⅴ类1.34倍和2.59倍; 屋面径流COD和TN浓度超过水质标准Ⅴ类1.8倍和 2.6倍。屋面径流中溶解态COD和TN分别占全量的72.78%和57.99%; 地面径流溶解态TN占全量的61.59%。2) 径流初期污染严重, 随着降雨过程逐渐降低, 最终趋于稳定。各下垫面污染物初期浓度从大到小依次为水泥地面、沥青地面、铺装地面、平屋面、斜屋面。冲刷过程中, 随雨强增大, 各下垫面污染物浓度升高, 呈波动式变化。各下垫面污染物均有冲刷初期效应, 下垫面初期冲刷强度从强到弱依次为平屋面、斜屋面、水泥地面和沥青地面。前期降雨强度越大, 污染物初期浓度越大, 初期效应越显著。降雨强度为大雨时, SS 浓度呈指数型衰减。降雨强度为小雨时, SS浓度先稳定, 随着降雨变密集开始逐渐减小。降雨强度为暴雨, 但降雨过程集中在中后期时, SS浓度呈先增大随后减小的趋势变化。3) 指数冲刷模型对屋面和水泥地面污染物径流冲刷模拟效果较好, 斜屋面、平屋面、水泥地面全量污染物冲刷系数分别为0.871, 0.765和0.025 mm⁻¹, 屋面冲刷强度远大于地面。斜屋面溶解态COD与颗粒态COD冲刷系数相近, 冲刷强度大。平屋面、水泥地面的颗粒态COD冲刷系数均大于溶解态COD, 颗粒态COD冲刷强度更大。     

斑节对虾白斑综合症暴发流行与水体理化因子的关系

用海水化学分析方法每天检测5口斑节对虾（Penaeus manodon）养成池两茬共90余天9项水质指标,结果表明它们的变化范围是：温度14．7－31．8℃、盐度13．6－30．6、溶解氧2．3－9．8水质指标,结果表明它们的变化范围是：温度14．7－31．8℃、盐度13．6－30．6、溶解氧2．3－9．8mg／L、pH7．3－9．5、硫化物（S^2-）0－0．13mg／L、磷酸盐（PO4^3-P）0－2．33mg/L、硝酸氮（NO3－N）0－1．33mg／L、亚硝酸氮（NO2^2-N)0．0．28mg／L、氨态氨（NH4^ -N NH3-N)0-0.66mg/L, 皆在斑节对虾该项指楠的耐受范围内,且无论这些因子含量如何变化,5口虾池两茬在虾养殖55d后皆因患WSS而死亡,表明在所检测的虾池这些水质因子并非WSSV感染暴发流行的指标因子。     

生物滤池处理微污染原水中氨氮及“氮亏损”影响因素分析

为探讨饮用水生物滤池对NH4+-N去除和"氮亏损"现象的影响因素,测定生物滤池进出水中NH4+-N,NO2--N,NO3--N等指标.结果表明,陶粒生物滤池对NH4+-N的去除率从14.97%到60.99%,活性炭生物滤池对NH4+-N的去除率从16.59%到83.02%;陶粒和活性炭滤池对NH4+-N的去除率都随着流速的增加而降低;陶粒滤池内NH4+-N的去除率随着气水比和C∶N的增加而先增加后下降;NH4+-N的去除率在活性炭滤池内随C∶N的增加而降低,气∶水的增加而增加;气∶水对两种生物滤池中NH4+-N去除的影响最大.陶粒生物滤池氮亏损的量从0.10 mg/L到0.70 mg/L,活性炭生物滤池氮亏损量从0.11 mg/L到1.01 mg/L;氮亏损量随着流速增加而降低,随着气水比增加而增加,随着C∶N的增加而先下降后增加;气水比对陶粒和活性炭生物滤池的氮亏损量影响最大.     

下沉式绿地对雨水径流污染物的削减效果及影响因素分析

为探究下沉式绿地对雨水径流污染物的削减效果及影响因素,采用室外种植箱的方式进行模拟试验,研究不同植物配置、不同下垫面雨水径流、不同土壤层厚度以及不同污染物浓度对下沉式绿地削减污染物的影响。结果表明,不同植物配置的下沉式绿地对削减NH+4-N的影响差值为9.6%,即依次:高羊茅(57.3%)三种混合植物(55.0%)鸢尾(50.4%)鼠尾草(47.7%);对削减TP的影响差值为5.3%,即依次:高羊茅(56.4%)三种混合植物(54.4%)鼠尾草(53.8%)鸢尾(51.1%);对削减COD的影响差值为8.9%,即依次:三种混合植物(39.4%)高羊茅(37.8%)鸢尾(33.1%)鼠尾草(30.5%)。不同植物配置的下沉式绿地对重金属(Cu、Zn、Pb)的削减效果很好,达95%以上。下沉式绿地对三种下垫面雨水径流污染物的削减效果依次:硬质屋顶沥青路面绿地;不同土壤层厚度和污染物浓度对下沉式绿地削减常规污染物的影响呈正相关,对下沉式绿地削减重金属的影响不大。因此,本研究可为下沉式绿地在控制雨水径流污染问题提供一种优化途径的新思路。     

开封市龙亭湖水体沉积物中N、P污染分析

以龙亭湖西湖为研究对象,共采集到23个水体样品和23个沉积物样品,据此分析测定水体和沉积物中TN、TP、NH4．N、NO3．N、NO2．N、PO4等含量,并对N、P各种存在形态进行分析测定．通过对水体和沉积物污染状况。以及沉积物污染对上覆水体水质影响的研究表明：对照地表水国家标准GB-3838-2002氨氮含量标准,龙亭湖水体上覆水集中于1、2、3、4类,其中3类水所占比例最高;沉积物对上覆水体NH4-N、NO3-N起到一定程度的净化作用,却是NO2．N、PO4的储存库,是龙亭湖上覆水体的一个内在污染源．研究结果为龙亭湖水体污染治理提供重要的决策依据．