高气速间歇式生物过滤去除高负荷H2S

采用生物过滤法,以鸡粪堆肥和PE混合物为填料,在高气速条件下间歇式处理高负荷H2S废气。空床停留时间为20、15、10、6.7和5 s时,入口浓度3 000 mg/m3下的平均去除率分别为100%、100%、96.5%、89.2%和90.5%。高气速EBRT为5 s时,高入口负荷2 147 g/(m3.h)时的去除负荷为2 023 g/(m3.h),去除率达94%。采用Michaelis-Ment-en模型进行生物降解宏观动力学研究,其中Ks为550 mg/m3,Vm为6.8×104g/(m3.d)。结果表明,在实验温度17～24℃,湿度30%～50%下,生物过滤法间歇式处理高气速高负荷H2S的去除性能好。     

利用废弃物衍生燃料的热化学处理法制富含氢气合成气

为了探讨利用热化学方式从城市垃圾中制取富含氢气合成气过程的要素影响,解析氢气发生特性及其与主要影响要素之间的关系。在分析了城市生活垃圾组分特性的基础上,将其加工成组分均一的废弃物衍生燃料(refuse de-rived fuel,RDF),并在700、800和900℃等3个温度条件下,分别开展了RDF的热解、气化及水蒸汽气化等实验。研究表明,RDF的加工不但可有效降低垃圾含水率,还可将垃圾热值提高近1倍。温度和添加水蒸汽是从RDF中制取富含氢气合成气过程中的关键影响要素。其中,温度对氢气生成起到至关重要的决定作用,温度的提高对促进H2浓度的提高有利,同时,在气化过程中添加水蒸汽,可有效促进CO和H2等有价气体组分生成。在900℃的高温水蒸汽气化处理过程中,可获得H2浓度最高为34.13%的合成气。另外,800℃热解过程所产生的合成气热值最高,达到14 509 kJ/Nm3。     

间歇运行式生物滴滤池处理油漆废气中试研究

为研究间歇运行式生物滴滤池对油漆生产厂废气净化能力,建立一座中试规模生物滴滤池（BTF）,接种降解菌群,采用8 h/d运行方式净化某油漆厂包装车间废气,并用PCR-DGGE技术揭示BTF细菌群落结构与工艺运行条件间的联系。油漆厂包装车间废气中挥发性有机物（VOCs）主要为甲苯、乙苯、混合二甲苯（间、对和邻二甲苯）,BTF对甲苯、乙苯、混合二甲苯最大去除率分别为88.8%、83.7%和86.3%。DGGE分析显示,BTF稳定运行时,主要优势菌相对丰度较为稳定（F,P>0.05）,其细菌多样性显著低于启动期（F,P>0.05）;同时,下层填料细菌多样性高于上层填料,其细菌结构变化也较上层明显;另外,提升培养液浓度至2倍和4倍对菌群结构亦无显著影响。     

NiO-CuO/ZSM-5催化剂对催化裂化烟气的脱硫脱硝性能

采用浸渍法制备了不同NiO和CuO质量分数的NiO-CuO/ZSM-5催化剂,并以CH4为还原剂研究了NiO-CuO/ZSM-5催化剂对催化裂化烟气的脱硫脱硝活性。XRD分析结果表明,NiO质量分数为4%、CuO质量分数为6%的催化剂4%NiO-6%CuO/ZSM-5中的ZSM-5结构完好,CuO和NiO高度分散在ZSM-5骨架中,表明具有较好的催化活性。4%NiO-6%CuO/ZSM-5的脱硫脱硝起活温度均较低,无氧条件下最高NO转化率和SO2转化率分别为94.7%和95.9%,O2体积分数为1.0%时的NO转化率和SO2转化率分别为97.7%和89.0%。     

Evaluation of a classification method for biodegradable solid wastes using anaerobic degradation parameters

We studied the biochemical and anaerobic degradation characteristics of 29 types of materials to evaluate the effects of a physical composition classification method for degradable solid waste on the computation of anaerobic degradation parameters, including the methane yield potential (L₀), anaerobic decay rate (k), and carbon sequestration factor (CSF). Biochemical methane potential tests were conducted to determine the anaerobic degradation parameters of each material. The results indicated that the anaerobic degradation parameters of nut waste were quite different from those of other food waste and nut waste was classified separately. Paper was subdivided into two categories according to its lignin content: degradable paper with lignin content of <0.05 g g VS^?1, and refractory paper with lignin content >0.15 g g VS^?1. The L₀, k, and CSF parameters of leaves, a type of garden waste, were similar to those of grass. This classification method for degradable solid waste may provide a theoretical basis that facilitates the more accurate calculation of anaerobic degradation parameters.     

堇青石负载Pd和过渡金属氧化物催化剂的表征及其对CO的催化氧化活性

以堇青石蜂窝陶瓷(CC)为载体,采用浸渍法制备了堇青石负载Pd和过渡金属混合氧化物催化剂,记作Pd-M-Mn(M=Cu,Co,Fe,Ni)/CC。实验结果表明:Pd-Co-Mn/CC催化剂的催化活性最高;随着Pd负载量的增加,CO转化率提高;当Pd负载量为1.00%时,反应温度为150℃时CO转化率达到98%,200℃时CO转化率达到100%;在反应温度150℃条件下,Pd-Co-Mn/CC催化剂(Pd负载量1.00%)的CO转化率在前30h内小幅度下降,随后稳定在90%以上,反应100h后,催化剂表面颜色由黑色变为棕褐色。     

Polychlorinated dibenzo-p-dioxin and dibenzofuran in urban air of an Andean city

Particle-bound polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) in ambient air were monitored together with particulate matter less than 10 μm (PM₁₀) at three sampling sites of the Andean city of Manizales, Colombia; during September 2009 and July 2010. PCDD/Fs ambient air emissions ranged from 1 fg WHO-TEQ m⁻³ to 52 fg WHO-TEQ m⁻³ in particulate fraction. The PM₁₀ concentrations ranged from 23 μg m⁻³ to 54 μg m⁻³. Concentrations of PM₁₀ and PCDD/Fs in ambient air observed for Manizales - a medium sized city with a population of 380 000 - were comparable to concentrations in larger cities. The highest concentrations of PCDD/Fs and PM₁₀ found in this study were determined at the central zone of the city, characterized by public transportation density, where diesel as principal fuel is used. In addition, hypothetical gas fractions of PCDD/Fs were calculated from theoretical K_p data. Congener profiles of PCDD/Fs exhibited ratios associated with different combustion sources at the different sampling locations, ranging from steel recycling to gasoline and diesel engines. Taking into account particle and gas hypothetical fraction of PCDD/Fs, Manizales exhibited values of PCDD/Fs equivalent to rural and urban-industrial sites in the southeast and center of the city respectively. Poor correlation of PCDDs with PM₁₀ (r = −0.55 and r = 0.52) suggests ambient air PCDDs were derived from various combustion sources. Stronger correlation was observed of PCDFs with PM₁₀. Poor correlation between precipitation and reduced PM₁₀ concentration in ambient air (r = −0.45) suggested low PM₁₀ removal by rainfall.     

Decay profile and metabolic pathways of quinalphos in water, soil and plants

The widespread occurrence of pesticide residues in different agricultural and food commodities has raised concern among the environmentalists and food chemists. In order to keep a proper track of these materials, studies on their decay profiles in the various segments of ecosystem under varying environmental conditions are needed. In view of this, the metabolites of quinalphos in water and soil under controlled conditions and in plants, namely tomato and radish in field conditions have been analysed and possible pathways suggested. In order to follow the decay of the pesticide, an HPLC procedure has been developed. Studies conducted in water at different temperatures, pH and organic content reveal that the persistence of the pesticide decreases with the increase in all the three variables. In the three different types of soils studied, the effect of pH is more or less apparent on a similar line. On an average a faster decay is observed in the case of plants than in water and soil. The decay profiles in all these cases follow first order kinetics. The metabolites were identified by GC-MS. The investigations reflect that degradation occurs through hydrolysis, S-oxidation, dealkylation and thiono-thiol rearrangement. The pathways seem to be complex and different metabolites were observed with the change in the matrix. Quinalphos oxon, O-ethyl-O-quinoxalin-2-yl phosphoric acid, 2-hydroxy quinoxaline and quinoxaline-2-thiol were observed in all the matrices. Results further indicate that the metabolites, 2-hydroxy quinoxaline and oxon, which are more toxic than parent compound, persist for a longer time.     

电除尘器进口矩形烟道气流分布改进的CFD模拟

应用CFD软件对某电厂电除尘器进口矩形烟道内气流分布进行数值模拟.结果表明:电除尘器原进口矩形烟道监测截面的气流分布极其不均匀,数值模拟结果与实验结果速度分布趋势比较吻合.基于此,通过多次改变电除尘器进口矩形烟道内导流板的数量、位置、尺寸等结构参数,使得改造后烟道监测截面风量偏差降到了±2.2%,气流分布相对均方根值均...     

不同来源废水COD、TOC与Cl-的关系

通过对含盐化工废水(A)、受潮汐影响的河流水(B)、城市生活污水处理厂排水(C)、采油废水(D)4种不同来源废水进行为期15 d的采样监测,测定了其COD、TOC和Cl-浓度,分析比较了3种废水指标之间的关系,其中COD分别使用重铬酸钾法、氯气校正法和碘化钾碱性高锰酸钾法3种方法进行测定.实验结果表明,4种废水Cl-浓...