Chemical speciation and mobility of heavy metals in municipal solid waste incinerator fly ash

Chemical speciation is a significant factor that govems the toxicity and mobility of heavy metals in municipal solid waste incinerator fly ash. Sequential extraction procedure is applied to fractionate heavy metals( Pb, Zn, Cd, Cu, and Cr) into five defined groups: exchangeable, carbonate, Fe-Mn oxide, organic, and residual fractions. The mobility of heavy metals is also investigated with the aid of toxicity characteristic leaching procedure. In the fly ash sample, Pb is primarily presented in the carbonate (51%) and exchangeable(20% ) fractions; Cd and Zn mainly exist as the exchangeable(83% and 49% respectively) ; Cu is mostly contained in the last three fractions(totally 87% ) ; and Cr is mainly contained in the residual fraction(62% ). Pb, Zn and Cd showed the high mobility in the investigation, thus might be of risk to the natural environment when municipal solid waste incinerator fly ash is landfilled or reutilized.     

吸烟与非吸烟肺癌患者中P53基因突变的检测

P53基因定位于人类第17号染色体的短臂,野生型P53基因是肿瘤抑制基因。这一基因正成为研究人类肿瘤DNA的主要目标。作者运用聚合酶链反应－单链构象多态性技术（PCR－SSCP）,研究了45例石蜡包埋的肺癌组织标本中肿瘤抑制基因P53基因突变,结果发现在P53基因的第5～8外显子中共检测到19例P53基因突变的样本,检出率为42.2％,并且发现吸烟的肺癌患者中P53基因突变的检出频率明显高于非吸烟的肺癌患者。     

灾害救助评估理论方法研究与展望

灾害救助评估是一种辅助决策工具,收集和分析灾害及灾害救助信息,为灾害救助活动的决策、规划和控制提供有效的信息支持,其内涵主要包括4个方面:①评估灾害对社会产生的影响;②灾害应急抢险需求与方案优化;③救助资源可获得性;④促进和加速灾后恢复与区域发展的可行性。灾害救助过程包括规划、数据收集与调查、分析与解读、趋势预测、辅助决策、灾害监测等6个环节。灾害救助评估内容按照灾害救助阶段总体分为应急快速评估和灾后详细评估两大类。其中,应急快速评估主要侧重于灾情和应急救助需求,是灾害救助评估的传统研究领域,为应急抢险和受灾人口基本生活保障提供信息支持;灾后详细评估则主要用于全面分析灾害对社会、经济、生态环境系统造成的损失和影响,为灾后恢复与重建提供辅助决策支持。     

中国固体废物法规体系框架分析

固体废物污染与其它环境污染不同,具有综合性、长期性和潜在性。固体废物管理更为强调综合利用和全过程管理,必须通过立法建立科学完善的法律制度来加强固体废物的管理。有关固体废物污染防治的法律、法规、部门规章、地方法规和环境技术标准构成了固体废物法规体系的基本框架。在系统分析现有固体废物法规中存在的问题的基础上,对固体废物管理的法规框架进行了探讨。通过立法,以“统一协调,分工负责”的原则规范各部门对固体废物的管理职能。还强调通过立法、健全监督机制、从法律上限制个人对行政权的滥用、制订技术政策与环境技术标准。除了行政责任外,论文还着重强调了环境违法者的民事责任和刑事责任。     

北京城市生态系统研究与进展

一、城市生态系统研究的兴起 环境问题,特别是环境污染问题的产生,是人类在追求经济发展和社会进步中缺少环境意识和知识,把自然作为商品利用,一味索取高额利润,把环境作为产品生产中的免费的废弃物堆放场,产品成本不必为此付出代价,从而造成环境危机的悲剧。     

Effects of carbon tax on environment under duopoly

Environment, Development and Sustainability - Environment protection and green development is of great importance. Therefore, this paper attempts to propose an environmentally friendly and...     

我国《新化学物质环境管理办法》修订探讨

介绍了我国新化学物质环境管理的相关要求;结合国际新化学物质环境管理经验和近年国内生态环境保护形势的要求,分析了我国新化学物质环境管理制度存在的主要问题;从调整管理类别、明确物质范围、简化申报类型、建立排查机制、强化主体责任、授权技术内审、简化信息报告、完善相关内容等方面对我国《新化学物质环境管理办法》的修订完善进行了探讨。     

油田高含盐污水雾化蒸发的数值模拟

基于FLUENT软件,对油田高含盐污水的雾化蒸发过程进行了数值模拟,得到了逆流型雾化蒸发塔内的流场分布特性,对比分析了不同操作参数对蒸发效果的影响。结果表明:液滴蒸发速率沿塔体中心轴线自上而下呈加快趋势;进口空气流速与温度是影响液滴蒸发的关键操作参数,提高流速及温度均可加快液滴的蒸发速率;当进口空气流速达到0.4 m/s后,对蒸发速率的影响减弱;当进口空气温度达到313 K后,对蒸发速率的提高作用不大;喷雾锥角的变化对蒸发速率影响不明显;液滴越细化,蒸发速率越快。     

Impact of food to microorganism ratio and alcohol ethoxylate dosage on methane production in treatment of low-strength wastewater by a submerged anaerobic membrane bioreactor

The effects of food to microorganism (F/M) ratio and alcohol ethoxylate (AE) dosage on the methane production potential were investigated in treatment of low-strength wastewater by a submerged anaerobic membrane bioreactor (SAnMBR). The fate of AE and its acute and/or chronic impact on the anaerobic microbes were also analyzed. The results indicated that AE had an inhibitory effect to methane production potential (lag-time depends on the AE dosage) and the negative effect attenuated subsequently and methane production could recover at F/M ratio of 0.088–0.357. VFA measurement proved that AE was degraded into small molecular organic acids and then converted into methane at lower F/M ratio (F/M<0.158). After long-term acclimation, anaerobic microbe could cope with the stress of AE by producing more EPS (extracellular polymeric substances) and SMP (soluble microbial products) due to its self-protection behavior and then enhance its tolerance ability. However, the methane production potential was considerably decreased when AE was present in wastewater at a higher F/M ratio of 1.054. Higher AE amount and F/M ratio may destroy the cell structure of microbe, which lead to the decrease of methane production activity of sludge and methane production potential.

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陶瓷厂喷雾干燥塔白烟形成的机理及解决措施

针对陶瓷厂烟囱冒“白烟”,造成环境污染的现象,提出了“降温法”和“升温法”两种治理方案,并对“升温法”方案建立了数学模型,通过数值求解,得到需要升高的最小临界温度值。计算结果已用于陶瓷厂烟气治理中,验证了其正确性。