Variability of dust iron solubility in atmospheric waters: Investigation of the role of oxalate organic complexation

Atmospheric dust deposition is a major external iron source for remote surface ocean waters. Organic complexation is known to play a role in the dissolution of iron-containing minerals. In this paper, we present our study on the effect of oxalate on dust iron solubility in simulated rainwater. Our results reveal that the solubility of iron carried by analogs of different African dusts varies with the dust source. Our experiments indicate a positive linear correlation between iron solubility and oxalate concentration. Soluble iron (SFe) increases from 0.0025(±0.0005)% to 0.26(±0.01)% of total iron, considering all dust sources and with oxalate concentrations ranging from 0 to 8 μM. These results show that the observed variability of iron solubility in aerosols collected over the Atlantic Ocean is, at least partly, due to an increase in dust iron solubility, with the presence of oxalate complexation, rather than to the presence of more soluble anthropogenic iron. Considering the mineralogical composition of those particles, experiments with pure minerals (hematite, goethite and illite) were performed to study the dissolution process. We found that oxalate promotes the solubility of iron contained in clay and hence confirmed that more than 95% of SFe from soil dust is provided by clay (illite). This experimental work enables us to establish a parameterization of iron solubility in dust as a function of oxalate concentration and based on the individual iron solubility of pure iron-bearing minerals usually present in dust particles. Finally, our results emphasize that oxalate contributes to iron solubility on the same order of magnitude as the acid processes. Organic complexation appears to be a process that increases iron solubility and likely enhances the bioavailability of iron from dust.     

吴泾工业区扬尘污染治理中降尘监测的影响因素研究

降尘监测可以较客观地反映与评价城市区域扬尘污染水平。及时掌握降尘污染状况,对区域扬尘污染治理措施成效和评价城市区域环境空气质量具有实际意义。降尘监测具有采样设备简单、操作简便易行、成本相对较低等特点。但是监测周期长、环节多等都会影响降尘监测的准确性。本文通过对吴泾工业区扬尘污染治理中降尘数据分析发现,降尘监测中存在降尘数据波动大、受周边环境影响大、人为损坏多等诸多因素的影响,就这些影响因素进行分析探讨,并提出了若干建议和解决方法。     

基于超低电容特性的微尘在线监测技术研究

为了更有效地测量工业烟尘排放浓度,研究了一种电容特性的微尘在线监测技术,利用电容传感器输出电压来反映粉尘质量。介绍了电容法测量粉尘量的原理、测量系统组成等,研究了粉尘质量与电容传感器输出电压的关系。对5种不同粉尘的测量结果进行分析表明,粉尘质量与电容传感器输出电压之间存在着一定的比例关系,其相关系数高达0.99。同时进行了微尘在线测量的研究,并采用电容特性曲线对测量系统进行了标定,从而验证了电容法在线微尘监测的可行性。     

Ash deposition impact on the energy performance of photovoltaic generators

A little known side effect of the atmospheric air pollution is the degradation of photovoltaic (PV) cells’ performance due to the deposition of solid particles varying in composition, size and origin. In this context, an experimental-based investigation is conducted in order to compare the energy performance of two identical pairs of PV-panels; the first being clean and the second being artificially polluted with ash, i.e. a by-product of incomplete hydrocarbons’ combustion mainly originating from thermal power stations and vehicular exhausts. A series of systematic measurements of current intensity, voltage output and solar radiation are executed simultaneously for the clean and the polluted PV-panel, so that the effect of several mass depositions on the PVs’ power output, energy yield and conversion efficiency may be determined. According to the results, a considerable deterioration of the PV-panels’ performance is obtained, i.e. almost 30% energy reduction per hour or 1.5% efficiency decrease (in absolute terms) for ash accumulation on the panels’ surface reaching up to 0.4 mg/cm².     

南通市降尘时空分布特征及影响因素

对2004年—2009年南通市降尘监测数据进行分析,结果表明,市区降尘污染较轻,年均值全部达标,在6年间呈波状变化态势;从各月分布来看,3—7月降尘污染较为严重;在各功能区中,受降尘污染程度从大到小依次为:居民区>工业区>商业交通区>文教区。提出,应继续推进城区企业工艺改造升级,加快燃煤锅炉淘汰;施工(运输)期间对易产生扬尘的建筑材料应采取密闭存储、设置围挡等有效措施并保证建筑垃圾及时清运、施工车辆及道路及时清扫冲洗;加大城市的绿化建设和道路的硬化建设,尽量避免道路开挖。     

我国粉尘爆炸事故原因及预防对策

论述了我国粉尘爆炸事故的分类和宏观发展趋势，分析了造成粉尘爆炸事故多发的原因，提出了预防粉尘爆炸事故的对策。     

粉尘爆炸反应工程学简要综述

１９９３年在波兰召开的第五届国际粉尘爆炸学术会议上，邓煦帆曾在论文中提议建立粉尘爆炸反应工程学，并提出学科的目的意义、性质、主要组成部分和研究方法。本文拟将国内外有关本学科范围内的贡献，加以简要综述，以期能逐渐形成本学科的自身体系和特点。     

移动式颗粒床除尘器最佳入口风速下的阻力计算

分析论述了ＹＸＫＣ型除尘器在最佳入口风速下的阻力计算方法及其影响，指出了进一步研究和改进设计的方向与途径。     

气体、粉尘爆炸灾害及其安全技术

对可燃性气体、蒸汽、粉尘的爆炸特性及其抑爆、隔爆安全技术进行了系统的研究 ,并对常见的可燃性气体、蒸汽和粉尘的各种爆炸特性参数和气体抑爆安全技术参数进行了实验测定。根据实验测定结果得到的结论对这种可燃性物质的安全应用具有重要的参考价值     

对某煤矿29年防尘投入的成本效益分析报告

从卫生经济学角度出发,对山东某煤矿就尘肺病所造成经济损失进行了调查分析,采用类回顾性群组对比法,分析、评价了29年来(1962—1990年)该矿采取防尘措施所取得的经济效益,为进一步开展预防尘肺病的卫生经济学研究提供科学依据。