溴添加对燃煤烟气汞形态转化的影响

在一维管式沉降炉燃烧试验装置上,以汞的氧化率为评价指标,进行了溴化物种类、添加浓度、添加方式等因素对燃煤烟气汞形态转化影响的实验研究.结果表明: 溴对汞的氧化起促进作用,汞氧化率在一定的范围快速增加,超过此范围缓慢增加.不同的煤质,不同的溴添加物,这个范围是不同的;综合考虑添加成本,操作难易程度以及汞的氧化率,添加同浓度的溴化物时,汞的氧化率由低到高的排列顺序依次是:HBr炉后< HBr炉前< CaBr2< NaBr.在本实验条件下,汞的氧化效果最佳的条件是,褐煤中添加200mg/kg溴化钠,汞的氧化率约72%;亚烟煤添加1000mg/kg溴化钠,汞的氧化率约83%.     

煤层瓦斯压力测定的合理封孔注浆压力研究

煤层瓦斯压力测定是煤矿安全生产基础参数测定的重要内容之一,测压成功的关键是封孔技术。当围岩裂隙较发育时需要采用压力注浆封孔,注浆压力就成为封孔的技术关键。为了确定一定围岩岩性条件下的合理封孔注浆压力,采用数值模拟的方法对测压钻孔塑性区大小进行了仿真模拟,并根据浆液渗流规律和钻孔围岩性质之间的关系建立了浆液流动数学模型,得出了合理的注浆压力为4MPa,结合新型“两堵一注”囊袋式封孔装置与CPD8M型煤层瓦斯压力自动测定仪进行了现场应用,结果表明4MPa的注浆压力满足平煤十三矿试验现场围岩条件下的封孔要求,对同类条件下瓦斯压力测定具有一定的指导意义。     

黄山大气气溶胶新粒子生长特性观测分析

利用2012年9月22日~10月28日黄山地区大气气溶胶、二氧化硫和臭氧观测数据,结合气象数据,分析气溶胶新粒子的生成-增长特征.分析发现,在33个有效观测日中,有新粒子生成-增长的观测日占总数的18.2%,其中晴天的发生频率为37.5%,新粒子生成-增长都开始于晴天上午,与无新粒子观测日相比,太阳辐射量、风速、SO2及O3浓度较高,环境温度和相对湿度较低.气溶胶新粒子的增长具有由小及大的特点,核模态气溶胶粒子(10~20nm)数浓度最先增加,爱根核模态粒子(20~50nm)数浓度随着时间推移逐渐增大,但浓度峰值依次下降,平均增长率为3.58nm/h. SO2浓度先于核模态气溶胶数浓度到达峰值,其氧化后的产物H2SO4为新粒子的核化提供前体物,并且参与新粒子的增长过程,当SO2浓度较低时,不会发生新粒子生长事件.     

水溶性吸收剂对甲苯废气的吸收性能

液体吸收法应用于处理工业有机废气涉及到2个关键因素,即吸收剂的选择与吸收液的再生处理. 选择8种水溶性吸收剂——2种氟碳表面活性剂(FSO100和FSN100)、2种非离子表面活性剂〔TW80(吐温80)和SP20(斯盘20)〕、2种阴离子表面活性剂〔脂肪醇聚氧乙烯醚硫酸钠(AES)和脂肪醇聚氧乙烯醚羧酸钠(AEC)〕及2种类表面活性剂〔β-CD(β-环糊精)和SA(乙酸钠), 对模拟甲苯废气进行了动力学吸收试验,研究吸收性能和加热蒸馏法对甲苯回收与吸收剂溶液再生的可行性. 结果表明:吸收剂类型是影响甲苯吸收能力的最主要因素. 2种氟碳表面活性剂吸收液的甲苯吸收能力最强,其次是SP20与AES,而其他4种吸收剂溶液对甲苯的吸收能力很弱. 上述3类吸收剂对甲苯的初始去除率分别为80%～90%、75%左右与60%～70%,甲苯饱和吸收浓度(以w计)分别为0.58～3.45、0.38～1.44与0.14～1.01 mg/g. 除TW80吸收液热稳定性差、不宜采用加热蒸馏方法再生外, 其他吸收剂溶液经5次重复使用,甲苯回收率可达70%～85%,并能保持其原有吸收性能. 甲苯分配系数计算结果表明,FSO100和FSN100分别为0.41、0.62, SP20和AES分别为0.76、0.95, 其他4种吸收剂溶液在1.12～3.54之间;甲苯分配系数与饱和吸收浓度呈负相关、与体积传质系数呈正相关. 因此,2种氟碳表面活性剂吸收液对甲苯的吸收能力强,加热蒸馏法回收甲苯与再生吸收液具有经济性,用于处理甲苯废气具有广泛的应用前景.      

Assessment of oxidative and UV-C treatments for inactivating bacterial biofilms from groundwater wells

Microorganisms are ubiquitous in natural environments and in water supply infrastructure including groundwater wells. Sessile-state microorganisms may build up on well surfaces as biofilms and, if excessive, cause biofouling that reduces well productivity and water quality. Conditions can be improved using biocides and other traditional well rehabilitation measures; however, biofilm regrowth is inevitable given the continuous introduction of microorganisms from the surrounding environment. Alternative and less invasive well maintenance approaches are desirable for reducing biofilm densities while also minimizing harmful disinfection-by-products. The primary objective of this research was to evaluate effectiveness of alternative treatments for inactivating microorganisms comprising biofilms. A novel approach was designed for in situ growth of biofilms on steel coupons suspended from ‘chandeliers’. After more than 100 days of in situ growth, biofilms were harvested, sampled, and baseline biofilm densities quantified through cultivation. Ultraviolet-C (UV-C) and oxidative treatments including hydrogen peroxide (H₂O₂), ozone (O₃) and mixed oxidants were then applied to the biofilms in laboratory-scale treatments. Microbial inactivation was assessed by comparing treated versus baseline biofilm densities. H₂O₂ was the most effective treatment, and decreased density below baseline by as much as 3.1 orders of magnitude. Mixed oxidants were effective for the well having a lower density biofilm, decreasing density below baseline by as much as 1.4 orders of magnitude. Disparity in the response to treatment was apparent in the wells despite their spatial proximity and common aquifer source, which suggests that microbiological communities are more heterogeneous than the natural media from which they originate.     

Advanced purification and comprehensive utilization of yellow phosphorous off gas

Yellow phosphorous is an important raw material in the chemical industry. However, during the production of yellow phosphorous, high concentrations of carbon monoxide and other impurities are released. Without appropriate purification and removal, this off gas has potential to cause severe pollution problems once released. Purified yellow phosphorous off gas can be beneficially reused as a raw material in chemical production for synthesis of high value-added chemical reagents. In this paper, the significance of purification and reutilization of yellow phosphorous off gas are explored. The principles, processes, and main characteristics of the technologies for purification and reuse of yellow phosphorus off gas (including technical measurements of impurity reduction, relevant engineering cases, and public acceptance of the technologies) are summarized. In view of the existing problems and scientific development requirements, this paper proposes several recommendations for green production based on the concept of recycle economics. We conclude that advanced purification and comprehensive reutilization can be an effective solution for heavy pollution resulting from yellow phosphorous off gassing.     

张集矿综采工作面瓦斯治理措施及效果分析

张集矿属于煤与瓦斯突出矿井,针对目前所开采的17266工作面地质构造条件复杂、瓦斯涌出量大、处于突出危险区等瓦斯治理难题,采取"风排瓦斯、高抽巷穿层钻孔抽采、运输巷、回风巷顺层钻孔抽采和上隅角埋管抽采"等瓦斯综合治理措施,用分源预测法得出工作面绝对瓦斯涌出量为30.3 m3/min。结果表明,工作面的主要瓦斯涌出来源为本煤层瓦斯涌出。工作面风排瓦斯量11.0 m3/min,工作面瓦斯抽采率达63.0%以上。     

模糊支持向量机在煤与瓦斯突出预测中的研究

模糊支持向量机(FSVM)综合了模糊理论和支持向量机(SVM)的学习理论,不仅继承了SVM在小样本情况下所具有的较强识别能力的特点,并且比SVM拥有更好的学习能力。在FSVM算法中,每个样本被赋予一个隶属度值,使得构造目标函数时不同的样本有不同的贡献,达到最大限度的消除噪声或者孤立点的效果。运用了灰色关联分析(GRA)对煤与瓦斯突出指标进行提取,引入了一个合适的模糊隶属度函数,并在此基础上提出了基于FSVM的煤与瓦斯突出预测的模型,通过实际数据的验证和其他预测方法的对比,证明了FSVM模型能够满足煤与瓦斯突出预测的要求。最后,将FSVM和传统SVM对同一组数据进行训练,证明了FSVM相比较传统SVM拥有更高的精确度。     

平煤股份六矿“U+L”通风综采面最佳横川间距确定

随着煤层开采深度的增加,煤层瓦斯含量不断增加,采空区瓦斯涌出量也随之上升,"U"型通风方式容易出现上隅角瓦斯超限等问题,影响煤矿安全生产,而"U+L"型通风方式中滞后横川和瓦斯抽放的运用对消除上隅角瓦斯超限和工作面瓦斯防治具有明显的作用。根据尾巷、横川及上隅角处瓦斯浓度符合规程且工作面横川间距最远时最经济合理的原则,针对平煤六矿戊8-22310工作面实际情况,利用Fluent软件模拟了尾巷有、无抽放时采空区瓦斯分布规律,得出了尾巷有抽放时和无抽放时最远横川间距。研究成果对"U+L"型工作面横川间距确定及工作面瓦斯防治提供了理论指导。     

基于GAHP-BOCR解决瓦斯隧道安全施工决策问题

施工单位依据实践经验提出了不同于《铁路瓦斯隧道技术规范》的施工措施,为了评价不同施工措施的优劣性,选用灰色层次分析法和利益-机会-代价-风险模型。首先建立瓦斯隧道安全施工评价准则体系,运用灰色理论处理数据,得到准则和子准则对于瓦斯隧道安全施工的权重影响值;其次评价每个子准则对于BOCR属性值,得到BOCR对于总目标的影响程度,并对每个施工措施的B、O、C、R进行评价得出综合计算结果;最后对不同施工措施提出相应的意见。