加速碳酸化技术对城市垃圾焚烧飞灰重金属稳定性影响研究

对南方某城市生活垃圾焚烧厂新鲜焚烧飞灰对CO₂的吸收及其碳酸化的过程进行了研究,实验从水分添加量、CO₂的分压等因素,考察了飞灰中重金属Pb的稳定化效果,并利用X射线衍射实验(XRD)、扫描电镜实验(SEM)对反应机理进行了分析.结果表明,不添加水分时,焚烧飞灰对CO₂的吸收效果较差;当水分添加量大于10％时,焚烧飞灰对CO₂的吸收效果较好.焚烧飞灰对纯CO₂的吸收效果较好,空气中的CO₂含量较低,在反应1 d后吸收效果不是十分明显.XRD实验结果表明,CO₂的吸收会使焚烧飞灰中大量的Ca(OH)₂与CO₂反应转化为CaCO₃,从而降低焚烧飞灰的碱性;部分重金属的氧化物会被碳酸化成生相应的碳酸盐.SEM实验结果表明,经过碳酸化处理后的飞灰颗粒表面生成了片状和圆柱状的晶体物质.     

长江口盐沼植物对营养盐和重金属的吸收、分布与滞留研究

测定3种盐沼植物体内TN、TP、重金属Cu、Zn、Pb和Cd的含量,计算了3种盐沼植物地上部分TN、TP和重金属库的大小.结果表明,3种盐沼植物在养分的分配模式上显著不同,3种盐沼植物地上部分重金属含量均低于地下部分;互花米草地上部分的养分库和重金属库均大于芦苇和海三棱镳草,表明其对养分和重金属的吸收与滞留效率更高.如果从湿地植物净化的角度来考虑,收获互花米草对河口环境的净化作用最佳,特别对P的去除效率最高;但另一方面,互花米草的入侵将会显著改变长江口湿地生态系统的生物地球化学循环过程,如提高沉积物中重金属的生物可利用性,有可能把更多的重金属输入河口水体和食物网,使湿地成为重金属的源而不是汇.     

二氧化碳灭火系统扑灭汽车发动机舱内火灾试验研究

本文使用二氧化碳灭火系统进行了汽车发动机舱火灾灭火试验,试验表明:系统采用闭式洒水喷头自动启动时,在风的作用下,火羽向风的下游偏移,可能导致下游的喷头启动,不能有效灭火.系统手动启动时,在发动机舱内部安装4个或者8个开式喷头,均能迅速扑灭汽车发动机舱火灾,且具有灭火时间短,灭火剂用量少,灭火效果好的特点.     

Oxidation catalyst of iron oxide suppressing dioxin formation in polyethylene combustion

A new iron oxide catalyst, which has a superior oxidation activity in carbon monoxide and polyethylene (PE) combustion, was synthesized by an aqueous solution reaction. Catalytic oxidation of carbon monoxide over six kinds of hematite obtained from the goethite was done using a microcatalytic pulse reactor, and the composition of the hematite with the highest oxidation activity was determined. With the aim of suppressing dioxin formation on combustion, incineration tests of solid wastes in PE refuse bags with and without the goethite were carried out using a commercial semibatch-type incinerator with a combustion chamber of 6.2 m³. The result confirmed that the concentration of dioxins in the flue gas decreased considerably when the refuse was incinerated in PE bags manufactured with goethite. Received: July 24, 2000 / Accepted: October 18, 2000     

Black carbon aerosol and carbon monoxide in European regionally polluted air masses at Mace Head, Ireland during 1995–1998

Continuous measurements of black carbon aerosol (BCA) at the Mace Head Atmospheric Research Station on the Atlantic Ocean coast of Ireland show the occurrence of dramatically elevated concentrations when regionally polluted air masses are advected to the station. These occurrences correlate well with similar elevations in carbon monoxide and a wide range of other trace gases monitored near-simultaneously with the BCA. Using daily sector allocation and a sophisticated Lagrangian dispersion model, two independent estimates of the European emission source strength of BCA that are required to explain the Mace Head observations have been made. The best estimates of the UK and European emission source strengths of BCA are 46±14 and [(482–511)±140]×10³ tonnes yr⁻¹, respectively, and these estimates compare favourably with published inventories, at least to within ±25%, though they are considerably smaller than the emissions employed in some early global climate model studies.     

Fe-Si添加剂对型煤燃烧固硫的促进作用

为提高型煤燃烧固硫效率,用微量Ｆｅ－Ｓｉ氧化物作为固硫促进剂加入钙碱吸收占,经１２００℃以上高温燃烧后进行固硫率计算,其固硫率可达６５％。用炉渣产物用Ｘ射线粉末衍射法进行物相鉴定,发现生成一种热稳定化合物ＣａＦｅ３（ＳｉＯ４）２ＯＨ,实验证明其有利于型煤燃烧固率的提高．     

循环流化床电站排放烟尘特性及痕量重金属分析

对35t h循环流化床电厂电除尘器入口和出口的烟气气溶胶进行分级取样,得到飞灰浓度和粒度分布以及电除尘器的分级脱除效率.电除尘器对PM10、PM2 5的脱除效率分别为94 34%和91 38%,使部分可吸入烟尘颗粒穿透除尘设备而直接排放到大气环境中.同时对不同粒度飞灰中重金属含量进行了测试,得到痕量元素浓度从高到低依次为Ni,Cr,Cu,Cd,Pb,Hg.痕量重金属含量与飞灰粒径有一定依附关系,其分布规律与煤成分、锅炉燃烧方式和痕量元素自身的挥发特性等因素有关.     

基于OCO-2卫星观测的浙江省典型城市CO2柱浓度变化特征及碳排放重点源识别应用

为有效制定城市层面的低碳发展政策,实现碳达峰的发展目标,利用碳卫星2号（OCO-2）监测的高分辨率大气CO₂柱浓度数据（XCO₂）,分析浙江省杭州、宁波和嘉兴3个典型城市的XCO₂变化特征,以及人类活动和XCO₂变化的关系;识别城市碳排放热点区域,评估碳排放热点源对XCO₂的影响,并利用拉格朗日粒子扩散模型（LPDM）进行验证。结果表明：（1）2016—2021年3个城市的XCO₂年增长量分别为3.1×10^-6,2.3×10^-6和2.2×10^-6,杭州的增长量最为明显;杭州和宁波在2019—2021年XCO₂增量明显,分别为8.0×10^-6和5.7×10^-6。杭州XCO₂的变化趋势与临安大气本底站CO₂观测数据的变化趋势一致。（2）与2017年相比,3个城市的建筑用地面积都略有增加,分别增加了0.9%,2.2%和4.8%;从人口和GDP数据来看,2016—2021年3个城市也均呈持续增加的变化趋势。表明CO₂浓度升高与人类活动密切相关。（3）XCO₂正距平高值区域基本都对应了碳排放热点源（电力企业）的下风向地区,电力企业CO₂的排放会导致下风向地区的XCO₂出现局地性增长,增量为7×10^-6～9×10^-6。     

Revealing the GHG reduction potential of emerging biomass-based CO2 utilization with an iron cycle system

● Greenhouse gas mitigation by biomass-based CO₂ utilization with a Fe cycle system. ● The system including hydrothermal CO₂ reduction with Fe and Fe recovery by biomass. ● The reduction potential quantified by experiments, simulations, and an ex-ante LCA. ● The greatest GHG reduction potential is −34.03 kg CO₂-eq/kg absorbed CO₂. ● Ex-ante LCA supports process optimization to maximize GHG reduction potential. CO₂ utilization becomes a promising solution for reducing anthropogenic greenhouse gas (GHG) emissions. Biomass-based CO₂ utilization (BCU) even has the potential to generate negative emissions, but the corresponding quantitative evaluation is limited. Herein, the biomass-based CO₂ utilization with an iron cycle (BCU-Fe) system, which converts CO₂ into formate by Fe under hydrothermal conditions and recovers Fe with biomass-derived glycerin, was investigated. The GHG reduction potential under various process designs was quantified by a multidisciplinary method, including experiments, simulations, and an ex-ante life-cycle assessment. The results reveal that the BCU-Fe system could bring considerable GHG emission reduction. Significantly, the lowest value is −34.03 kg CO₂-eq/kg absorbed CO₂ (−2.44 kg CO₂-eq/kg circulated Fe) with the optimal yield of formate (66%) and Fe (80%). The proposed ex-ante evaluation approach not only reveals the benefits of mitigating climate change by applying the BCU-Fe system, but also serves as a generic tool to guide the industrialization of emerging carbon-neutral technologies.     

黄土高原草地植被与土壤固碳量研究

在黄土高原自东南向西北,采用样带多点调查与定位监测相结合的研究方法,系统分析了不同草地类型封禁初期和封禁11 a草地生物量与固碳量变化特征。结果表明:4种草地类型地上活体植物、凋落物/地下活体根系和土壤中碳密度与碳储量分布规律均为森林草原＞梁塬典型草原＞丘陵典型草原＞荒漠草原;草地封禁11 a,地上活体植物、凋落物、0~100 cm活体根系和土壤中碳密度总量,森林草原类型为63.38~97.65 t·hm^-2,梁塬典型草原类型为49.04~68.80 t·hm^-2,丘陵典型草原类型为52.33~62.11 t·hm^-2,荒漠草原类型为11.93~19.62 t·hm^-2;碳储量4种草地类型分别为230.287 7 Tg C、332.306 7 Tg C、484.055 5 Tg C和113.856 3 Tg C;黄土高原草地总固碳量为573.10 Tg C,其中:活体植物为42.89 Tg C,占总固碳量的7.48%;凋落物为80.40 Tg C,占14.03%;活体根系为108.66 Tg C,占18.96%;土壤为341.15 Tg C,占59.53%。这充分表明,封禁不仅能使草地植被快速恢复和生物量增加,而且也是提高草地固碳潜力的一条重要途径。