Experimental thermal storage research of organic binary phase change materials in building environment

This paper aims to reveal the heat transfer mechanism of low-temperature phase change material (PCM) and design PCM heat storage device in building heating environment. Firstly, low-temperature binary PCMs of lauric acid and stearic acid are prepared, and their thermal properties are investigated by DSC. Then, shell and tube latent heat thermal energy storage units are conducted, and heat transfer experiments are carried out to analyze the heat transfer mechanism of PCM. The results demonstrate that natural convection plays an important role in heat transfer process, and the heat storage efficiency of PCMs can be significantly enhanced by increasing the fin width and improving the inlet heat transfer fluid (HTF) temperature. Furthermore, some proposals are put forward to guide the design of PCM storage device in building heating environment.     

KOH活化花生壳生物质炭对亚甲基蓝吸附性能研究

以花生壳生物质炭(P-BC)为原料,KOH为活化剂,采用化学活化法制得活化生物质炭(K-BC),通过考察对亚甲基蓝的吸附性能,研究了花生壳生物质炭的最佳活化条件,并利用N2吸附-脱附实验、SEM等对最佳活化条件下的生物质炭进行表征。结果表明,K-BC活化的最佳条件为碱炭比为1.5∶1,活化温度为800℃,活化时间为90 min,此时K-BC的比表面积达到597.93 m2/g,总孔容达到0.76 cm3/g。并考察了亚甲基蓝初始浓度、pH等对K-BC吸附亚甲基蓝的影响,随着初始浓度的增加,吸附平衡时间显著延长,亚甲基蓝去除率显著降低;当pH=6时,K-BC对亚甲基蓝的吸附量最大;K-BC对亚甲基蓝的吸附动力学曲线符合伪二阶动力学模型,吸附平衡时K-BC对亚甲基蓝的吸附能力为80~149.95 mg/g。     

RPB-O3/H2O2法处理硝基苯模拟废水

在超重力场中,研究了硝基苯模拟废水的臭氧/双氧水(O3/H2O2)法处理效果,考察了超重力因子β、H2O2浓度、初始p H、液体流量及处理时间等因素对硝基苯去除率的影响。结果表明,硝基苯去除率随超重力因子β和处理时间的增加而增大,而随H2O2浓度、初始p H和液体流量的增加呈先增大后降低的趋势。当硝基苯初始浓度300 mg/L,工艺条件β=80、p H=10.0、臭氧质量浓度约为40 mg/L、H2O2浓度为4.9 mmol/L、液体流量为120 L/h时,循环处理35 min硝基苯去除率可达96.7%。处理时间60 min后,废水中硝基苯含量1.4 mg/L,COD为39 mg/L,达国家一级排放标准(GB 8978-1996)。在此条件下,硝基苯的降解过程符合准一级反应动力学。     

Fe(Ⅱ)EDTA络合吸收-铁粉还原再生脱除NO性能

利用Fe(Ⅱ)EDTA络合吸收-铁粉间歇还原再生脱除NO并回收氨资源的方法,实验研究了铁粉还原再生Fe(Ⅱ)(NO)EDTA的过程及其影响因素。结果表明,以0.015 mol/L的Fe(Ⅱ)EDTA做吸收剂,在起始p H 5.5、温度323K条件下吸收400×10-6~500×10-6的NO,脱除率95%以上;铁粉还原再生Fe(Ⅱ)(NO)EDTA过程可用缩芯模型阐释;铁粉添加量与搅拌强度直接决定了铁粉质点数量,是影响反应的重要因素;实验中Fe(Ⅱ)(NO)EDTA络合液150 m L,氧气含量为5%时,搅拌速度900 r/min、粒径为0.12 mm的铁粉浓度5.3 g/L、温度353 K、p H=6为最适宜再生条件。     

基于GIS的太湖流域主要生态风险源危险度综合评价研究

以太湖流域主要生态风险源为评价对象,充分考虑多类型多等级风险源作用强度的差异性,构建了风险源危险度评价模型,并在此基础上依据风险源发生机率、强度及作用范围等建立了太湖流域洪涝、干旱、极端气象、土壤侵蚀及污染排放等主要生态风险源的危险度评价指标体系。在ArcGIS技术支持下,创建了太湖流域1 606个网格和24个县市的风险源危险度统计数据库,采用AHP权重法确定指标权重,运用叠加分析、空间分析等技术方法最终实现太湖流域单要素及综合生态风险源危险度的定量评价。结果表明流域内生态风险源的分布存在明显的空间分异规律。其中,高生态风险源危险区集中分布在环太湖北部一带,面积约占流域面积的1172%;较高危险区主要呈“西北 北 东北 东”半环状分布格局,所占面积约2452%,危险度较低的区域集中在流域西南部的苕溪流域一带,面积占1566%。此外,不同区域主导生态风险源组成亦不同,约599%的区域是以污染排放为主导生态风险源,主要分布在镇江 宜兴 长兴 安吉一线以东的地区;2545%的区域主导生态风险源为干旱,主要集中在镇江 宜兴 长兴 安吉一线以西;1244%的区域是以洪涝灾害为主导风险源,集中分布在湖州、宜兴等地;而以水土流失、极端气象灾害作为主导风险源地区相对较为分散,所占比例较小     

絮凝#x02014;微波辐射#x02014;Fenton试剂氧化法深度处理焦化废水

用絮凝#x02014;微波辐射#x02014;Fenton试剂氧化法深度处理焦化废水,研究了微波辐射时间、微波功率、FeSO₄加入量、H₂O₂加入量和废水pH对废水处理效果的影响。实验结果表明：在聚合氯化铝加入量为350mg/L、聚丙烯酰胺加入量为12mg/L、废水pH=5、FeSO₄加入量为250mg/L、H₂O₂总加入量为1400mg/L、H₂O₂分3次投加、微波功率为400W、微波辐射时间为60min的条件下,处理后出水的浊度、色度和COD去除率分别为98.59%,97.62%,86.21%。处理后出水澄清透明,COD为50.34mg/L,满足GB50050#x02014;2007《工业循环冷却水处理设计规范》的要求。     

废旧纺织品的回收及再利用

随着人民生活水平的不断提高,居民家中淘汰的各类废旧纺织品的产生量快速增加。废旧纺织品作为一种可再生资源,其复杂性影响了回收后的资源化利用。废旧纺织品分类回收和再生纤维加工,提高了废旧纺织品回收及再利用水平,有助于弥补我国纺织原材料供给不足,实现织物资源的循环利用。     

一种包埋微生物复合填料的制备及性能评价

采用包埋法制备出一种复合生物填料,测其各项理化性质,并以NO。模拟废气验证其脱硝性能。填料主要由碳酸钙、牛粪堆肥腐殖质、菌剂载体、水泥、轻质珍珠岩、立体网状纤维及脱硝功能微生物等复合而成,粒径书12mm×20mm,自然堆积密度（471±0．8）kg／m2,持水量（49±1．3）％,比表面积3．91m2／g,平均机械强度（427．3±0．2）N,pH为10．5-0．2。填料能长期在潮湿环境中保持良好的粘结强度,并具有营养缓释及pH缓冲能力。包埋脱硝功能微生物复合填料中初期微生物数量5．3×10^5 CFU／g,运行60d后微生物数量达到8．6×10 8 CFU／g,闲置停运30d微生物有所减少,但重启后净化效率基本不变。当进气负荷低于I878mg／（13m3·h）,气体停留时间为14．47s时,BF,的去除率高达93．15％。     

电催化氧化处理除草剂异噁草酮废水的效能

为有效处理含异噁草酮除草剂废水,以Sb掺杂Ti／SnO2电极为阳极,不锈钢板为阴极,采用电催化氧化技术对异噁草酮废水进行降解,研究了不同影响因素对异噁草酮去除率的影响,并分析了异噁草酮的降解效果。结果表明,当异噁草酮初始浓度为100mg／L、电流密度为20mA／cm2、电解质投加量为0．10mol／L,反应120min后,异噁草酮去除率达到94％,此时TOC去除率为57．9％,能耗为25kWh／m2,且废水的可生化性能显著提高。     

Direct N2O decomposition over La2NiO4-based perovskite-type oxides

Direct decomposition of N₂O by perovskite-structure catalysts including La₂NiO₄, LaSrNiO₄, and La_0.7Ce_0.3SrNiO₄ was investigated. The catalysts were prepared by the Pechini method and characterized by x-ray diffraction (XRD), BET, scanning electron microscopy (SEM), and O₂-TPD. Experimental results indicate that the properties of La₂NiO₄ are significantly improved by partially substituting La with Sr and Ce. N₂O decomposition efficiencies achieved with LaSrNiO₄ and La_0.7Ce_0.3SrNiO₄ are 44 and 36%, respectively, at 400ºC. As the temperature was increased to 600ºC, N₂O decomposition efficiency achieved with LaSrNiO₄ and La_0.7Ce_0.3SrNiO₄ reached 100% at an inlet N₂O concentration of 1,000 ppm, while the space velocity was fixed at 8,000 hr^?1. In addition, effects of various parameters including oxygen, water vapor, and space velocity were also explored. The results indicate that N₂O decomposition efficiencies achieved with LaSrNiO₄ and La_0.7Ce_0.3SrNiO₄ are not significantly affected as space velocity is increased from 8,000 to 20,000 hr^?1, while La_0.7Ce_0.3SrNiO₄ shows better tolerance for O₂ and H₂O_(g). On the other hand, N₂ yield with LaSrNiO₄ as catalyst can be significantly improved by doping Ce. At a gas hour space velocity of 8,000 hr^?1, and a temperature of 600ºC, high N₂O decomposition efficiency and N₂ yield were maintained throughout the durability test of 60 hr, indicating the long-term stability of La_0.7Ce_0.3SrNiO₄ for N₂O decomposition.

Implications:Nitrous oxide (N₂O) not only has a high global warming potential (GWP₁₀₀ = 310), but also potentially destroys ozone in the stratosphere. Pervoskite-type catalysts including La₂NiO₄, LaSrNiO₄, and La_0.7Ce_0.3SrNiO₄ are applied for direct N₂O decomposition. The results show that N₂O decomposition can be enhanced as Sr and Ce are doped into La₂NiO₄. At 600ºC, N₂O decomposition efficiencies achieved with LaSrNiO₄ and La_0.7Ce_0.3SrNiO₄ reach 100%, demonstrating high activity and good potential for direct N₂O decomposition. Effects of O₂ and H₂O_(g) contents on catalytic activities are also evaluated and discussed.