共查询到10条相似文献，搜索用时 59 毫秒
1.
Xiaolu ZHANG Hongwei YANG Xiaofeng WANG Yu ZHAO Xiaomao WANG Yuefeng XIE 《Frontiers of Environmental Science & Engineering》2015,9(6):995-1003
Swimming has become a popular exercising and recreational activity in China but little is known about the disinfection by-products (DBPs) concentration levels in the pools. This study was conducted as a survey of the DBPs in China swimming pools, and to establish the correlations between the DBP concentrations and the pool water quality parameters. A total of 14 public indoor and outdoor pools in Beijing were included in the survey. Results showed that the median concentrations for total trihalomethanes (TTHM), nine haloacetic acids (HAA9), chloral hydrate (CH), four haloacetonitriles (HAN4), 1,1-dichloropropanone, 1,1,1-trichloropropanone and trichloronitromethane were 33.8, 109.1, 30.1, 3.2, 0.3, 0.6 µg∙L−1 and below detection limit, respectively. The TTHM and HAA9 levels were in the same magnitude of that in many regions of the world. The levels of CH and nitrogenous DBPs were greatly higher than and were comparable to that in typical drinking water, respectively. Disinfection by chlorine dioxide or trichloroisocyanuric acid could substantially lower the DBP levels. The outdoor pools had higher TTHM and HAA9 levels, but lower trihaloacetic acids (THAA) levels than the indoor pools. The TTHM and HAA9 concentrations could be moderately correlated with the free chlorine and total chlorine residuals but not with the total organic carbon (TOC) contents. When the DBP concentration levels from other survey studies were also included for statistical analysis, a good correlation could be established between the TTHM levels and the TOC concentration. The influence of chlorine residual on DBP levels could also be significant. 相似文献
2.
Electrolytic manganese residue (EMR) is a type of solid waste discharged from the process that converts solid manganese carbonate of rhodochrosite into soluble Mn(II) and generates anode mud under electrolysis. The experimental material was a filtrate created by using distilled water as a dispersal agent for the EMR, followed by simple filtration. A calculated amount of sodium carbonate was added to recover the soluble Mn(II) via precipitation into manganese carbonate. Data showed that Mn concentration may be markedly decreased from 2069 to 36 mg/L, thereby reaching a recovery rate as high as 98%. Analysis demonstrated that precipitation of Mn(II) from a leached aqueous solution followed first-order kinetics. The findings indicate that the reaction rate constant decreased as temperature gradually rose and that its apparent activation energy Ea was ?10.48 kJ/mol. 相似文献
3.
苦味酸(PA)作为一种高爆物和环境污染物,近年来引起了广泛的关注. 本研究提出了一种新型荧光碳量子点(C-dots)探针,可用于快速、高选择性和高灵敏度的PA检测. 探针采用中药材川木香为碳源,通过水热法一步合成. 在荧光碳量子点溶液中加入PA,通过荧光共振能量转移机理,碳量子点的荧光被有效猝灭. 结果表明,碳量子点最大激发波长为360 nm,最大荧光发射波长为415 nm,荧光量子产率为28.4%. 方法检测PA响应时间2 min,线性范围0.2—800 μmol·L−1,检测限(LOD)63 nmol·L−1,实际水样中加标回收实验,回收率为98.8%—101.7%,相对标准偏差(RSD)为1.2%—2.7%. 相似文献
4.
本研究采集2015年9月至2016年8月石河子市不同类型天气下大气颗粒物样品,根据气象条件进行霾与沙尘分类,使用热光碳分析仪DRI 2001A进行有机碳（organic carbon,OC）与元素碳（elemental carbon,EC）测定,采用最小比值法估算二次有机碳（second organic carbon,SOC）质量浓度,主成分分析法（principle component analysis,PCA）分析其可能来源.结果表明：中霾天气下OC和EC平均质量浓度达到20.85±5.03、2.75±0.46 μg·m-3（沙尘天气18.9±4.4 μg·m-3,2.6±0.9 μg·m-3）.二次有机碳SOC在中霾天气下质量浓度为10.62±3.94 μg·m-3（沙尘天气9.3±3.7 μg·m-3）,占OC浓度67%（沙尘天气67%）.霾与沙尘天气OC与EC相关系数低于非霾非沙尘天气,表明霾与沙尘天气较非霾非沙尘天气有着复杂的污染源.PCA分析表明,霾与沙尘天气下的碳气溶胶的主要排放源为机动车尾气,固定燃煤源和道路扬尘.本项研究分析了石河子市霾和沙尘天气下的碳气溶胶分布,有望为中国西部城市的霾和沙尘天气治理提供依据. 相似文献
5.
The effects of biologically active carbon (BAC) filtration on haloacetic acid (HAA) levels in plant effluents and distribution systems were investigated using the United States Environmental Protection Agency’s Information Collection Rule (ICR) database. The results showed that average HAA5 concentrations in all locations were 20.4 μg·L-1 and 29.6 μg·L-1 in ICR plants with granular activated carbon (GAC) and ICR plants without GAC process, respectively. For plants without GAC, the highest HAA levels were observed in the quarters of April to June and July to September. However, for plants with GAC, the highest HAA levels were observed in the quarters of April to June and January to March. This HAA level profile inversely correlated well with water temperature, or biologic activity. For GAC plants, simulated distribution samples matched well with distribution system equivalent samples for Cl3AA and THMs. For plants with and without GAC, simulated distribution samples overestimated readily biodegradable HAAs in distribution systems. The study indicated that through HAA biodegradation, GAC process plays an important role in lowering HAA levels in finished drinking water. 相似文献
6.
2017年1月-12月期间在四川省宜宾市布置4个点位,共采集360个PM2.5样品膜,采用美国沙漠研究所DRI Model 2001型热光分析仪测定PM2.5样品中OC、EC的浓度值,应用OC/EC比值法对SOC进行了估算.结果表明,宜宾市PM2.5年均浓度为75.2 μg·m-3.OC、EC年均浓度分别为14.3 μg·m-3和4.30 μg·m-3,季节变化趋势为冬季>秋季>春季>夏季,OC占PM2.5比例为19.0%,为PM2.5重要组成部分.SOC年均浓度为4.70 μg·m-3,对OC贡献较大,在OC中占比为29.3%;SOC在OC中的占比春季>冬季≈秋季>夏季.进一步对OC1、OC2、OC3、OC4、EC1、EC2、EC3、和OPC进行主成分分析,结果表明机动车尾气、燃煤排放和生物质燃烧是宜宾市PM2.5中OC和EC的主要贡献源,可贡献PM2.5中碳组分的54.0%-69.0%. 相似文献
7.
Xiaoyan SHI Kebin HE Weiwei SONG Xingtong WANG Jihua TAN 《Frontiers of Environmental Science & Engineering》2012,6(4):463-469
The effects of a diesel oxidation catalytic (DOC) converter on diesel engine emissions were investigated on a diesel bench at various loads for two steady-state speeds using diesel fuel and B20. The DOC was very effective in hydrocarbon (HC) and CO oxidation. Approximately 90%–95% reduction in CO and 36%–70% reduction in HC were realized using the DOC. Special attention was focused on the effects of the DOC on elemental carbon (EC) and organic carbon (OC) fractions in fine particles (PM2.5) emitted from the diesel engine. The carbonaceous compositions of PM2.5 were analyzed by the method of thermal/optical reflectance (TOR). The results showed that total carbon (TC), OC and EC emissions for PM2.5 from diesel fuel were generally reduced by the DOC. For diesel fuel, TC emissions decreased 22%–32% after the DOC depending on operating modes. The decrease in TC was attributed to 35%–97% decrease in OC and 3%–65% decrease in EC emissions. At low load, a significant increase in the OC/EC ratio of PM2.5 was observed after the DOC. The effect of the DOC on the carbonaceous compositions in PM2.5 from B20 showed different trends compared to diesel fuel. At low load, a slight increase in EC emissions and a significant decrease in OC/EC ratio of PM2.5 after DOC were observed for B20. 相似文献
8.
白城地区近50年土壤有机碳动态变化研究 总被引：1，自引：2，他引：1
基于白城地区第一次、第二次全国土壤普查和野外现场采样共217个土壤剖面数据,利用＂土类-土地利用类型＂权重方法,估算白城地区11个土类从20世纪50年代至2009年近50年的土壤有机碳密度（SOD）和碳储量（SOC）,分析SOD变化规律,探讨其时空演化特征,结果表明,①近50年来,除水稻土和栗钙土SOD随时间增加外,其余各土类SOD随时间持续降低;但不同时期泥炭土SOD均最高,盐碱土均为最低。②近50年来,白城地区的SOD从92.22±21.13 t.hm-2减少至68.01±10.76 t.hm-2;表现为自北向南、自西向东降低的空间分布规律。③近50年来,白城地区SOC减少了6.2×107 t,各县市SOC呈逐年降低态。 相似文献
9.
Pramit Verma;Justyna Chodkowska-Miszczuk;Akhilesh Singh Raghubanshi; 《Sustainable Development》2024,32(5):4518-4534
Energy is an indispensable resource for economic development and the well-being of society. Due to heterogeneity in socioeconomic conditions, households consume direct energy and produce emissions differently. Analysing energy emissions from heterogeneous socioeconomic groups helps to identify foci for intervention and create policies for sustainable cities. This study aimed to measure household emissions in Varanasi city and investigate the impact of heterogeneous socioeconomic variables on household emissions. Varanasi represents a million-plus rapidly urbanising city. Analysis of variance (ANOVA) and non-parametric regression revealed the relationship between end-use energy emissions and socioeconomic variables for five income classes. Biomass-based fuels constituted a significant proportion of energy (about 16%–20%) in low- to middle-income groups, however, electricity consumption dominated in upper-middle- and high-income groups. A fuel-stacking pattern was found, particularly in cooking activities. LPG was critical to replace solid biomass-based fuels. To meet the present needs and absorb the impact of a growing population, energy policies and infrastructure should focus on accessibility and efficiency. An inclusive low-carbon policy with a specialised focus on socioeconomic differences is needed for energy sustainability. 相似文献
10.
于2017年冬季12月13—21日在青藏高原东缘理塘地区分昼夜采集PM2.5样品,并用DRI2001A热光碳分析仪测定了有机碳(OC)和元素碳(EC)的质量浓度,研究青藏高原PM2.5中碳组分的化学特征及主要来源,以期为理塘地区制定污染排放政策提供参考。结果表明,2017年冬季青藏高原东缘理塘地区PM2.5平均质量浓度为44.34μg·m?3,OC和EC的质量浓度为12.72μg·m?3和3.85μg·m?3,分别占PM2.5质量浓度的29.61%和8.96%。通过经验公式,计算得到总碳气溶胶(TCA)质量浓度为24.20μg·m?3,占PM2.5的54.84%,说明碳质气溶胶对青藏高原东缘理塘地区PM2.5有着十分重要的贡献。OC和EC在白天和夜间都有较高的相关性(相关系数分别为0.74和0.91),表明OC和EC的来源基本一致,受燃烧源影响较大。其中白天的相关系数低于夜间,说明青藏高原东缘理塘地区白天碳组分来源相对复杂。昼夜浓度对比显示,青藏高原东缘理塘地区PM2.5白天和夜间的质量浓度分别为53.88μg·m?3和33.44μg·m?3,OC和EC浓度白天高于夜间,表明白天人为排放相对较高。冬季观测期间,PM2.5中二次有机碳(SOC)昼夜浓度分别为1.11μg·m?3和3.03μg·m?3,分别占OC质量浓度的7.09%、26.59%,表明青藏高原东缘理塘城区白天碳组分主要为一次源。利用PMF 5.0软件对理塘城区碳组分进行进一步的解析,结果显示燃煤和生物质燃烧的混合源对总碳(TC)的贡献高达47.84%,占比最高;其次是汽车尾气和柴油车尾气源,贡献率分别为28.62%和23.54%。 相似文献