Sulfate-containing amendments to reduce methane emissions from rice fields: mechanisms,effectiveness and costs

Application of sulfate-containing amendments is oftensuggested as a mitigation option to reduce methane (CH₄) emissionsfrom rice (Oryza) fields. This paper discusses the mechanism andpotential of this mitigation option, reviews the relevant experimental data,and presents first, indicative costs of application. CH₄ emission datafor rice fields with sulfate-containing amendments are compiled toreinterpret the resulting reduction in CH₄ emission and find a generalrelationship between emission reduction and amount of sulfate applied. Thereduction in CH₄ emission depends on the amount of sulfate applied.However, absolute emission reduction is location specific and cannot bederived from the amount of sulfate (SO^2- ₄) applied only. We established alogarithmic relationship, across locations, between SO^2- ₄ application andfractional emission reduction relative to the emission of the non-amendedcontrol field. Recycling of SO^2- ₄ in the rhizosphere was essential to explainthe observed reductions in CH₄ emission for a number of theexperiments. The cost of applying SO^2- _{_4}-containing fertilizers varies acrosscountries and depends on local fertilizer prices. Since a fractional reductionis obtained, the cost-efficiency in terms of CH₄ mitigation per unitof SO^2- ₄ applied will be highest in high-emitting rice production systems.Provided the proper target areas are selected, the cost of SO^2- ₄-containingfertilizer as a mitigation option to reduce CH₄ emissions in rice fieldsis estimated at 5–10 US dollar per Mg CO₂-equivalent.     

聚合硫酸铁絮凝剂的物化性质研究

本文通过对直接氧化法聚合硫酸铁(PFS)的热力学研究,首次报道了PFS的一些物化数据:热容、积分溶解热和反应热效应,并根据稀溶液的依数性原理测定了PFS的平均分子量。     

涂装作业场所超细干粉灭火设备设计

涂装作业场所使用的油漆和溶剂一般是易燃易挥发的液体,因而此类场所的火灾爆炸危险很大.一旦发生事故,将会造成巨大的财产和人员损失.本文针对此类场所火灾爆炸事故的特点,分析对比了各种消防系统对此类场所火灾爆炸事故的控制能力,提出了超细干粉灭火系统相对于其他消防系统对于控制此类场所火灾爆炸危险的优点,同时也对探测器的选型进行了讨论,并结合实例进行了超细干粉灭火设备在涂装作业场所的应用设计.     

微生物菌粉与菌液矿化固结Zn~(2+)的研究与对比

利用碳酸盐矿化菌在底物诱导下的酶化作用,分解产生碳酸根离子,矿化固结环境(土壤水体)当中的游离重金属离子,减少其危险。文章以Zn2+溶液模拟重金属离子污染体系,研究过程中发现,生产的矿化产物主要是ZnO.5(OH)62(CO)3。分别用菌粉和菌液进行微生物矿化试验,对矿化产物进行底物分解率,SEM,XRD,矿化粒径的对比研究。从对比研究结果看,菌粉复活后,可以达到与菌液基本相同的矿化效果。而菌粉相对于菌液而言,其主要优势在于能长时间储存,产品体积小,运输起来更方便,因此,菌粉具有更广泛的应用性。     

胶团强化超滤处理含镍废水

胶团强化超滤(MEUF)是一种高效分离水中金属离子的技术。以无机陶瓷膜为媒介,采用胶团强化超滤法处理含镍废水,考察膜孔径,表面活性剂十二烷基硫酸钠(SDS)浓度、镍离子浓度、pH值等因素对胶团强化超滤过程的影响。实验结果表明:膜孔径、SDS浓度、pH值对镍离子截留率有显著影响。当废水温度为20℃,操作压力为0.15 MPa,膜孔径为20 nm,SDS浓度为6.0 mmol/L时超滤效果最好;在此条件下,镍离子的截留率达99.25%,膜通量为89.65 L/(m2.h)。     

垃圾筛上物衍生燃料(RDF)粘结剂筛选

分别以5%的煤粉、CaO、污泥、电石渣作为添加剂,制备的垃圾RDF成型率和落下强度优于未添加对照组,RDF热值、储存性能均高于原垃圾,其中:RDF成型率和落下强度以电石渣最高,分别为90%和81.8%。热值以添加煤粉最高,达15899.2kJ/kg以上。原垃圾筛上物经过4周的储存后,产生1590mL渗滤液、挥发分含量减少了20.23%,臭度为五级,而RDF中均无渗滤液产生、挥发分无变化、臭味强度降为1级以下。灰色关联度计算结果表明:电石渣>煤粉>污泥>CaO,因此,电石渣是最佳粘结剂。     

Explosion behaviour of metallic nano powders

This paper describes experiences and results of experiments with several metallic dusts within the nanometer range. The nano dusts (aluminium, iron, zinc, titanium and copper) were tested in a modified experimental setup for the test apparatus 20 L-sphere (also known as 20-L Siwek Chamber), that enables the test samples to be kept under inert atmospheric conditions nearly until ignition. This setup was already introduced in earlier papers by the authors. It was designed to allow the determination of safety characteristics of nano powders under most critical circumstances (e.g. minimisation of the influence of oxidation before the test itself). Furthermore the influence of passivation on explosion behaviour is investigated and additional tests with deposited dust were carried out to describe the burning behaviour of all dusts. For a better characterisation all samples were tested with a simultaneous thermal analysis (STA). To minimise the influence of oxidation all samples were handled at inert conditions until shortly before ignition or start of the test respectively.     

生产工艺条件对菌粉爆炸特征参数的影响

利用扫描电镜及激光粒度分析仪,探究了不同生产工艺条件下医药中间体菌粉A和菌粉B的表面形状及粒径分布,并进行了热解分析,证实上述特征参数存在一定差别。在此基础上进行了爆炸特性参数研究。研究结果表明,上述两种菌粉爆炸下限处于70~90 g/m3,最大爆炸压力峰值0.4~0.5 MPa之间,爆炸性相对较弱,但也必须引起足够的重视。与菌粉B相比,菌粉A相对安全,因此条件许可时优先采用菌粉A生产工艺流程。     

脱硫石粉贮存库气化装置改造

对火电厂脱硫石粉贮存库运行过程中散装机出料口下料缓慢,进气母管及气化槽体中进粉等问题进行了分析,提出了改造对策,石粉贮存库气,石粉贮存气化装置改造后运行效果良好,以60t罐车为例,石粉的装车为例,石粉的装车时间同原来的30min减少到15min.     

聚合硫酸铁絮凝剂的绝热合成研究

本文通过对聚合硫酸铁（ＰＦＳ） 的动力学研究，发现ＰＦＳ的合成温度控制在５０ ℃以上就显著地提高了反应速度，缩短了反应周期。当相对水量Ｃ＝ ４ ．５ ～５ ．５ 时，采用工业级硫酸亚铁为原料，在催化氧化作用下，可以实现ＰＦＳ 的绝热合成工艺，去除加热设备，优化工艺过程。与直接氧化法ＰＦＳ相比，绝热法聚合硫酸铁（ＨＰＦＳ） 具有更优的混凝性能。