电感耦合等离子体发射光谱法测定土壤和沉积物中硫的适用性研究

为探讨不同消解方式下电感耦合等离子体发射光谱法测定土壤及沉积物中硫的适用性,研究了不同标准物质消解液建立的工作曲线、谱线干扰对分析结果的影响。结合土壤和沉积物来源特点、主成分和待测物含量、干扰物情况,筛选20个典型标准物质分别采用王水水浴法和四酸电热板法进行消解,研究了电感耦合等离子体发射光谱法中3条分析谱线(180.669、181.972、182.562 nm)测定样品中硫的情况。结果表明,0.500 0 g样品经10.0 mL王水(体积比1∶1)沸水浴消解4 h,采用电感耦合等离子体发射光谱仪分析谱线硫181.972 nm建立的18个标准物质工作曲线相关系数高达0.999 9,标准溶液实测浓度相对误差为-6.9%～16%,2个标准物质测定结果的精密度和认定值回收率分别为3.3%～4.3%和90%～96.7%,满足生态环境和自然资源行业的质量控制要求,该方法测定结果与波长色散X射线荧光标准分析方法具有可比性。建立工作曲线的标准物质应考虑待测物和干扰物含量,宜选用标准浓度认定值测试的相对误差而非工作曲线的相关系数作为评价工作曲线优劣的主要技术指标,谱线干扰的理论推导情况和实验结果在趋势...     

升流式污泥床对无机废水中氮硫转化及相互影响

采用无机含氨和硫酸盐(SO₄^2-)废水作为升流式污泥床(USB)反应器进水,研究了其对铵(NH₄⁺)和SO₄^2-的去除以及不同高度污泥层含氮、硫元素的转化途径.结果表明在反应器进水口处由于进水自含氧(外源性氧)和兼性厌氧菌受到氧化应激产生过氧化氢(内源性氧),两种“氧”共同存在下,反应器内生物脱氨量(以氮计)最高达40mg/L左右,且在USB反应器不同高度污泥层含氮化合物和含硫化合物的转化途径不同.在反应器底部污泥层,颗粒污泥表面氨氧化菌利用O₂将氨(NH₄⁺)氧化成亚硝酸盐(NO₂^-),在颗粒污泥内部厌氧氨氧化菌利用NH₄⁺和NO₂^-生成氮气(N₂)和硝酸盐(NO₃^-);同时,O₂     

农田生态系统大气氮、硫湿沉降通量的观测研究

2007年10月至2008年9月,借助自动降雨收集器(APS-2A)及自动气象观测站(VSALA-M52),在中国科学院红壤生态实验站(江西鹰潭)农田区内定位采集雨水样本,探讨了大气氮、硫湿沉降特征,估算了大气氮、硫的湿沉降向农田生态系统的输入通量.结果表明,雨水中氮、硫素的月质量浓度变异较大,全氮(T-N)、铵态氮(NH_4~+-N)、硝态氮(NO_3~--N)和硫(SO_4~(2-)-S)的月质量浓度,即ρ(T-N)、ρ(NH_4~+-N)、ρ(NO_3~-N)和ρ(SO_4~(2-)S)分别为1.09～7.84、0.64~6.25、0.34～1.83和0.95～7.64mg·L~(-1),均与降水呈负相关,其中ρ(T-N)、ρ(NH_4~+-N)、ρ(SO_4~(2-)-S)与降水的相关性达到比较显著水平(n=11,p<0.10).湿沉降月通量F(T-N)、F(NI_4~+N)、F(NO_3~--N)和F(SO_4~(2-)-S)分别为1.0～7.84、0.64～6.25、0.17～1.54和1.22～9.15 kg·hm~(-2),均与降水呈正相关,其中F(T-N)、F(NH_4~+-N)和F(SO_4~(2-)-S)与降水的相关性均达到显著水平(n=11,p<0.05).季节上,雨水氮、硫浓度及湿沉降氮、硫通量均呈冬春>夏秋的特性.湿沉降向农田生态系统输入N 35.94 kg·hm~(-2)·a~(-1)和S45.93 kg·hm~(-2)·a~(-1),其中NH4~+-N的年沉降通量为22.92 kg·hm~(-2),占湿沉降氮总量的63.75%.     

Bridging the gap between laboratory experiments and naturally occurring markets: An inferred valuation method

Several recent studies have found important differences between behavior in the laboratory and the field. We explore two possible causes for the divergence: social concerns and unfamiliarity with the traded good. Consistent with our conceptual model, we find that people overstated their preferences for relatively familiar goods with normative attributes and understated their preferences for a relatively unfamiliar good with low normative motivations in the laboratory as compared to the field. We also find that for goods with a normative dimension, a new method we refer to as inferred valuation has the potential to narrow the lab–field gap. In some cases, willingness-to-pay obtained from a conventional valuation elicitation method is more than twice the value from the new inferred valuation approach.     

低污染、低腐蚀、高效固体有机废物焚烧技术

通过分析固体有机废物与煤的燃料特性的不同及其对燃烧的影响 ,从工艺控制 ,温度控制 ,停留时间选择 ,送风控制 ,添加剂以及烟气循环使用等方面探讨低污染、低腐蚀、高效固体有机废物的焚烧技术。     

Phosphorus recovery from fosfomycin pharmaceutical wastewater by wet air oxidation and phosphate crystallization

Fosfomycin pharmaceutical wastewater contains highly concentrated and refractory antibiotic organic phosphorus (OP) compounds. Wet air oxidation (WAO)-phosphate crystallization process was developed and applied to fosfomycin pharmaceutical wastewater pretreatment and phosphorus recovery. Firstly, WAO was used to transform concentrated and refractory OP substances into inorganic phosphate (IP). At 200 °C, 1.0 MPa and pH 11.2, 99% total OP (TOP) was transformed into IP and 58% COD was reduced. Subsequently, the WAO effluent was subjected to phosphate crystallization process for phosphorus recovery. At Ca/P molar ratio 2.0:1.0 or Mg/N/P molar ratio 1.1:1.0:1.0, 99.9% phosphate removal and recovery were obtained and the recovered products were proven to be hydroxyapatite and struvite, respectively. After WAO-phosphate crystallization, the BOD/COD ratio of the wastewater increased from 0 to more than 0.5, which was suitable for biological treatment. The WAO-phosphate crystallization process was proven to be an effective method for phosphorus recovery and for fosfomycin pharmaceutical wastewater pretreatment.     

Quantification of carbamazepine and atrazine and screening of suspect organic contaminants in surface and drinking waters

A new approach for the identification of suspect trace organic contaminants in drinking and surface waters is presented. Samples were initially analyzed using a target determination method for two contamination tracers, carbamazepine (CBZ) and atrazine (ATZ). This method used offline solid-phase extraction and online solid-phase extraction techniques coupled to liquid chromatography-triple quadrupole mass spectrometry to accelerate the sample preparation process and improve method performance. CBZ and ATZ were found respectively in 31% and 56% of the samples, and concentrations were usually <20 ng L⁻¹. These samples were re-analyzed with a similar method on a quadrupole time-of-flight mass spectrometer to identify suspect contaminants by means of exact mass measurements and isotope patterns. A database of 264 common organic contaminants was built and used in conjunction with a Molecular Feature algorithm to identify the presence of these substances in drinking and surface water collected from different sources at various locations across Canada. Several organic contaminants were identified in the samples, but only the presence of caffeine, desethylatrazine, simazine and venlafaxine could be verified by comparison to pure standards. The presence of desethylatrazine was also confirmed by MS/MS experiments. These results suggest that target analysis for tracers of organic contamination may be a helpful tool to prioritize samples which should be further screened for suspect contaminants. This study also shows that the combination of separation techniques (offline and online SPE, LC) contribute to advance the applicability of high-resolution mass spectrometry for the identification of trace organic contaminants by accelerating the preparation step, reducing complexity and increasing analyte concentrations for optimal detection.     

中国2020年SO_2排放量控制在2070万t以下的可行性分析

根据SO2减排控制指标体系中16个指标的概况和变化趋势,对中国2020年SO2排放量做了系统地分析和预测,得到了三组预测图像。中国SO2排放量与国民生产总值（GDP）及其年均增长率、总能耗量及其年均增长率、能源经济环境发展模式（能源消费弹性系数）等12项指标成正相关,与SO2治理强度等4项指标成负相关,当各个指标控制在合理的范围内时我国2020年SO2减排目标是可以实现的。提出了2020年实现SO2减排目标的10个约束条件,如果不满足约束条件时,我国2020年SO2削减目标是不能实现的。     

Vertical fluxes of aromatic and aliphatic hydrocarbons in the Northwestern Mediterranean Sea

Aliphatic and aromatic hydrocarbon fluxes were measured in time series sediment trap samples at 200 m and at 1000 m depths in the open Northwestern Mediterranean Sea, from December 2000 to July 2002. Averaged fluxes of n-alkanes, UCM and T-PAH₃₅ were 2.96 ± 2.60 μg m⁻² d⁻¹, 64 ± 60 μg m⁻² d⁻¹ and 0.68 ± 0.59 μg m⁻² d⁻¹, respectively. Molecular compositions of both hydrocarbon classes showed a contamination in petrogenic hydrocarbons well above the background levels of such an open site, whereas pyrolytic hydrocarbons stand in the range of other open Mediterranean locations. Fluxes displayed ample interannual and seasonal variabilities, mainly related to mass flux variation while concentration evolutions trigger secondary changes in pollutant fluxes. High lithogenic flux events exported particles with a larger pollutant load than biogenic particles formed during the spring bloom and during the summer. Sinking hydrocarbons were efficiently transported from 200 m to 1000 m.     

Effects of organic matter and ageing on the bioaccessibility of arsenic

Arsenic-contaminated soils may pose a risk to human health. Redevelopment of contaminated sites may involve amending soils with organic matter, which potentially increases arsenic bioaccessibility. The effects of ageing on arsenic-contaminated soils mixed with peat moss were evaluated in a simulated ageing period representing two years, during which arsenic bioaccessibility was periodically measured. Significant increases (p = 0.032) in bioaccessibility were observed for 15 of 31 samples tested, particularly in comparison with samples originally containing >30% bioaccessible arsenic in soils naturally rich in organic matter (>25%). Samples where percent arsenic bioaccessibility was unchanged with age were generally poor in organic matter (average 7.7%) and contained both arsenopyrite and pentavalent arsenic forms that remained unaffected by the organic matter amendments. Results suggest that the addition of organic matter may lead to increases in arsenic bioaccessibility, which warrants caution in the evaluation of risks associated with redevelopment of arsenic-contaminated land.