区域土地利用类型对水源水中溶解性有机物丰度和荧光组分的影响

以潮白河密云段水体为研究对象,采用三维荧光光谱法及平行因子分析解析了潮白河饮用水源中溶解性有机物(DOM)来源和荧光特性,结合方差分析探讨了不同季节和区域土地利用类型对DOM浓度和荧光组分强度的影响.结果表明,潮白河密云段水体荧光溶解性有机物(FDOM)由5种荧光组分组成,包括微生物腐殖质2种,自生酪氨酸,还原醌类和陆...     

汾河流域地表水水化学同位素特征及其影响因素

汾河是山西的母亲河.由于水资源过度开发及社会经济发展影响,生态环境恶化.经过一系列治理保护措施,水质得到改善.利用统计学、Piper三线图和Gibbs模型等方法,分析了汾河流域地表水水化学和氢氧同位素特征及其来源,揭示了汾河流域地表水水质演化过程.结果表明,汾河干流地表水中主要水化学组分沿着径流路径含量逐渐增加;汾河上游地表水水化学类型主要以HCO₃·SO₄·Cl-Ca·Na·Mg为主,中游和下游地表水水化学类型主要以SO₄·HCO₃·Cl-Ca·Na·Mg为主.汾河流域地表水水化学组成主要受岩石风化作用和蒸发结晶作用影响,而降雨影响较小.Na⁺和K⁺主要来源于蒸发盐岩的溶解以及周边黄土中含Na矿物溶解,水体中Ca²⁺、Mg²⁺和HCO₃^-主要来源于碳酸盐岩的溶解,SO₄^2-除来源于石膏的溶解,还可能来源于汾河周边黄土层中硫化矿物的溶解.干流地表水δD和δ¹⁸ O平均值分别为-62.60‰和-8.42‰,氢氧同位素特征进一步表明其主要受蒸发作用的影响.流域内支流及岩溶水水化学组分差异较大.结果可为汾河流域生态修复保护及生态文明建设提供依据.     

黄河流域内蒙古段1951—2012年气温、降水变化及其关系

黄河流域内蒙古段是内蒙古自治区重要的经济发展区,研究其气候因子变化对流域水资源、区域经济社会发展及生态环境保护有重要意义。论文利用研究区及其周边地区52个气象站点1951—2012年气温与降水量资料,采用回归分析、年代均值比较、5 a滑动、气候倾向率和Mann-Kendall检验等方法,对气温与降水变化及其关系进行了分析。结果表明：近62 a来,研究区域平均气温、平均最高和最低气温均呈明显上升趋势（0.283 ℃/10 a、0.235 ℃/10 a、 0.590 ℃/10 a）,尤以20世纪90年代增温最为明显,冬季增长速率最快,对气温升高贡献最大。3类气温分别在1988、1989、1982年发生了突变,平均气温、平均最高气温突变时间均晚于平均最低气温。多年降水量年际变化较大,总体呈下降趋势（-1.48 mm/10 a）,但下降幅度不明显。年降水量与平均气温、平均最高气温、平均最低气温在20世纪80—90年代相关性较好,均呈上升趋势,而其他时期则呈阶段反对称变化。从季节上看,春季降水量与3类气温年值相关性最好;夏季降水量与3类气温的年际变化趋势类似;秋季降水量与3类气温呈阶段反对称性变化;冬季降水量与3类气温在20世纪90年代到21世纪呈反对称变化,其他年代则呈现一致的变化趋势。     

夏季渭河西安段溶解性有机质(DOM)的特征、分布及来源分析

通过紫外吸收光谱,三维荧光光谱结合平行因子分析(EEMs-PARAFAC)方法及主成分分析(PCA),研究了夏季渭河西安段水体中的溶解性有机质(DOM)的组成、来源,及其与水质指标的相关性.在研究区域共检出2种类别5个不同的DOM组分,分别为类腐殖质荧光组分C1、C2、C3、C5和1个类蛋白类荧光组分C4,5个组分具有...     

基于水土流失的景观格局分析方法

景观格局和生态过程是景观生态学研究的重要内容,但是很多研究只重视景观格局的研究,而忽略了生态过程的研究。文章针对水土流失这一重要生态过程,提出了基于水土流失过程的景观坡度指数和景观空间负荷对比指数,并对黄土高原泾河流域15个子流域的景观格局进行了分析,认为泾河流北部各子流域主要以水土流失的＂源＂景观为主,景观坡度指数大,空间负荷指数小,水土流失风险大;流域南部各子流域上游以＂汇＂景观为主,坡度指数大,中下游以＂源＂景观为主,景观空间分布不均衡,存在一定的水土流失风险;流域东部局部子流域主要以水土流失的＂汇＂景观为主,＂源＂景观相对较小,＂源＂-＂汇＂景观空间分布均衡,水土流失风险小。     

Effects of salinity on soil bacterial and archaeal community in estuarine wetlands and its implications for carbon sequestration: verification in the Yellow River Delta

Soils from two typical tidal salt marshes with varied salinity in the Yellow River Delta wetland were analysed to determine possible effects of salinity on soil carbon sequestration through changes in soil microbiology. The mean soil respiration (SR) of the salt water–fresh water mixing zone (MZ) was 2.89 times higher than that of the coastal zone (CZ) (4.73 and 1.63?μmol?m^?2?s^?1, respectively, p?Pseudomonas sp. and Limnobacter sp. that might have led to its higher dehydrogenase activity and respiratory rates. Additionally, the CZ possessed more Halobacteria and Thaumarchaeota with the ability to fix CO₂ than the MZ. Significantly lower soil salinity in MZ (4.25?g?kg^?1) was suitable for β-Proteobacteria, but detrimental for Halobacteria compared with CZ (7.09?g?kg^?1, p?相似文献   

纳米铁对沈阳细河水及周边村庄井水中重金属和溴的去除

在实验室条件下合成制得的纳米铁BET比表面积为49.16 m.2g-1,粒径范围为20—40 nm.通过批实验考察了纳米铁对沈阳细河河水和周边地下水中重金属及溴离子的去除效果.结果表明,纳米铁对水中Cr（Ⅵ）、Cu（Ⅱ）、Cd（Ⅱ）、Pb（Ⅱ）和As（Ⅲ）都有很好的去除效果,1.25 g.L-1纳米铁在30 min内,...     

Perfluorinated compounds in the Pearl River and Yangtze River of China

A total of 14 perfluorinated compounds (PFCs) were quantified in river water samples collected from tributaries of the Pearl River (Guangzhou Province, south China) and the Yangtze River (central China). Among the PFCs analyzed, perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) were the two compounds with the highest concentrations. PFOS concentrations ranged from 0.90 to 99 ng/l and <0.01–14 ng/l in samples from the Pearl River and Yangtze River, respectively; whereas those for PFOA ranged from 0.85 to 13 ng/l and 2.0–260 ng/l. Lower concentrations were measured for perfluorobutane sulfonate (PFBS), perfluorohexane sulfonate (PFHxS), perfluorooctanesulfoamide (PFOSA), perfluorohexanoic acid (PFHxA), perfluoroheptanoic acid (PFHpA), perfluorononaoic acid (PFNA), perfluorodecanoic acid (PFDA), and perfluoroundecanoic acid (PFUnDA). Concentrations of several perfluorocarboxylic acids, including perfluorododecanoic acid (PFDoDA), perfluorotetradecanoic acid (PFTeDA), perfluorohexadecanoic acid (PFHxDA) and perfluorooctadecanoic acid (PFOcDA) were lower than the limits of quantification in all the samples analyzed. The highest concentrations of most PFCs were observed in water samples from the Yangtze River near Shanghai, the major industrial and financial centre in China. In addition, sampling locations in the lower reaches of the Yangtze River with a reduced flow rate might serve as a final sink for contaminants from the upstream river runoffs. Generally, PFOS was the dominant PFC found in samples from the Pearl River, while PFOA was the predominant PFC in water from the Yangtze River. Specifically, a considerable amount of PFBS (22.9–26.1% of total PFC analyzed) was measured in water collected near Nanjing, which indicates the presence of potential sources of PFBS in this part of China. Completely different PFC composition profiles were observed for samples from the Pearl River and the Yangtze River. This indicates the presence of dissimilar sources in these two regions.     

EU-wide survey of polar organic persistent pollutants in European river waters

This study provides the first EU-wide reconnaissance of the occurrence of polar organic persistent pollutants in European river waters. More than 100 individual water samples from over 100 European rivers from 27 European Countries were analysed for 35 selected compounds, comprising pharmaceuticals, pesticides, PFOS, PFOA, benzotriazoles, hormones, and endocrine disrupters. Around 40 laboratories participated in this sampling exercise. The most frequently and at the highest concentration levels detected compounds were benzotriazole, caffeine, carbamazepine, tolyltriazole, and nonylphenoxy acetic acid (NPE₁C). Only about 10% of the river water samples analysed could be classified as “very clean” in terms of chemical pollution. The rivers responsible for the major aqueous emissions of PFOS and PFOA from the European Continent could be identified. For the target compounds chosen, we are proposing “indicative warning levels” in surface waters, which are (for most compounds) close to the 90th percentile of all water samples analysed.