符号数学运作双层区域火灾模型

本文运用符号数学MATLAB及MAPLEV计算双层区域模型ASET的方程式,考虑两条基本方程,报告由六所面积10至100平方米的房间,在2个设计火灾下共十二个模式例题的环境及结果也和ASET及FIREWIND程序比较。     

Thermodynamic analysis of fatty acid harvesting by novel carbon-based adsorbent

In this study, separation and concentration of fatty acids (FA) from the synthetic food processing wastewater containing low concentration of FA (250 mg/L) were investigated using expanded graphite (EG) as a novel adsorbent at different temperatures (298~318 K). The adsorption results were further analyzed to verify adsorption mechanisms and thermodynamics of FA onto EG. Results show that the adsorption of FA onto EG was explained well by the Langmuir model with the maximum adsorption capacity up to 8.01 g FA/g EG at 298 K, and considerably affected by temperature. The adsorption kinetics fitted with pseudo-second-order kinetic model and the adsorption mechanism analysis showed that the intraparticle diffusion was not the rate-limiting step, but the coalescence of FA droplets played the significant role for novel adsorption of FA onto EG. The calculated activation energy and thermodynamic parameters such as Gibbs free energy change (ΔG⁰), enthalpy change (ΔH⁰), and entropy change (ΔS⁰) indicated that the adsorption of FA onto EG was very feasible, was highly spontaneous, occurred physically, was exothermic in nature, and was stable in aquatic environmental changes. Overall, FA can be effectively harvested and concentrated from the food processing wastewater by EG even at low concentration.     

Estuarine dependency in a marine fish evaluated with otolith chemistry

Life-long strontium patterns in otoliths of the sciaenid Micropogonias furnieri caught in the southwestern Atlantic Ocean were examined to evaluate estuarine dependency and habitat use. Otolith Sr concentrations were on average 820?±?55?μg?g^?1 for freshwater, 1,751?±?101?μg?g^?1 for estuarine, and ranged from 2,000 to over 4,000?μg?g^?1 for marine waters. The examination of life-long otolith Sr revealed that 71?% of the marine-sampled fish moved toward brackish waters from age 0 to age 1, and that estuarine egress ranged from ages 2.1 to 4.1?years depending on the sampling area. Three different long-term patterns of Sr accumulation were observed and inferred to be the result of ontogeny and habitat shifts. Given that an estuarine Sr signature was consistently present in all sampled fish, M. furnieri is suggested to be a true estuarine-dependent species during its early life history.     

Effect of temperature on bacterial emissions in composting of swine manure

Swine manure was subjected to laboratory scale composting in order to quantify bioaerosols, i.e., airborne culturable bacteria and endotoxin, in the exhaust gas, which provided details on the effect of temperature on bacterial emissions. The concentration of airborne bacteria reached 31,250 colony-forming units (CFU)/m³ during the thermophilic stage of composting, and positively correlated with the temperature profile of the compost pile. Initially, the endotoxin concentration was 1820 endotoxin units (EU)/m³, but it decreased exponentially as the composting process proceeded. The temperature can be an excellent indicator of bacterial emissions during the composting process, indicating that the composting process requires a consistently high temperature to ensure sanitization of both compost and bacterial emissions. The cumulative emission data showed that emission factors was 11.2?13.5 CFU/g dry swine manure and that of endotoxin was 0.5?0.9 EU/g dry swine manure. The bacterial diversity in the bioaerosol was analyzed by polymerase chain reaction-denaturing gradient gel electrophoresis, revealing the presence of various gram-negative bacterial consortia.     

Effects of environmental conditions,low-level potassium,ethylenediaminetetraacetic acid,or combination treatment on radiocesium-137 decontamination in Napier grass

Environmental Science and Pollution Research - Phytoextraction is widely used to remove environmental pollutants such as heavy metals or radionuclides from soil. It is important to understand how...     

热脱附技术在修复石油烃污染土壤中的应用研究

采用热脱附技术处理实际石油烃污染土壤,考察影响热脱附效率的影响因素,并结合工程实际,初步确定热脱附技术的最优工艺参数.实验结果表明,热脱附技术可有效修复石油烃污染土壤,其中加热温度、停留时间是影响修复效果的关键因素.相同热脱附条件下,石油烃组分相对分子质量越大,饱和蒸气压越低,与土壤有机质结合能力越强,越不易脱附.当加...     

电石渣处理煤矿酸性废水技术的研究

利用电石渣对煤矿酸性废水进行处理,达到以废治废的目的。为此对该技术进行研究。在反应停留时间为29 h,pH为6.93时,出水总铁为4.00 mg/L、亚铁为2.01 mg/L、总锰为0.90 mg/L,去除率分别为:总铁:99.04%、亚铁:99.44%、总锰:86.86%。出水指标达GB 20426—2006《煤炭工业污染物排放标准》的要求。     

“预处理+水解酸化+活性污泥法”处理再生纸废水

介绍水解酸化+活性污泥法处理再生纸废水系统的设计及运行;运行结果表明:该工艺处理该类废水完全可行,运行效果稳定,出水完全达广东省地方标准DB 44/26—2001《水污染物排放限值》。     

基于MODIS时序影像的东湖环境变化分析

经济发展影响生态环境变化,文章利用MODIS时序影像数据,计算和分析地面植被、水域和建筑物分布区域,获取武汉东湖地区环境变化序列图像,从中分析2002年以来经济开发对植被、生态环境变化的影响,提出经济开发与环境保护意见。