Cleaner production for continuous digester processes based on hybrid Pareto genetic algorithm

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环境空气中PM2.5与PM10质量浓度关系的研究

采集大连市4个大气自动监测点位30dPM2.5和PM10质量浓度小时值的监测数据,通过对每个点位720个有效数据对的统计分析,研究二者质量浓度的相关性及 PM2.5/PM10比值的分布情况,并研究了气象因素对PM2.5与PM10的影响。结果表明,雾使PM2.5PM10浓度都减小,但二者比值也随之降低;强风会使PM10浓度增大,但PM2.5浓度却减小。     

Lignin and holocellulose from coir pith involved in trimethylamine (fishy odor) adsorption

Coir pith is a highly potential adsorbent for adsorbing trimethylamine(TMA). It harbors a higher adsorption capacity for TMA compared to commercial activated carbon(CAC). It was found that lignin and holocellulose extracted from coir pith played an important role in TMA adsorption. Lignin itself had the highest TMA adsorption capacity(269.01 mg/g)followed by holocellulose(75.43 mg/g), coir pith(14.3 mg/g) and CAC(10.26 mg/g),respectively. The pseudo-first-and second orders were applied to the kinetic data. For the adsorption of TMA by coir pith, the best fit was achieved by the pseudo-second order.Thermodynamic studies showed an endothermic and physico-chemical adsorption process between TMA and the coir pith. TMA desorption study suggested that only 14%–47% of TMA was desorbed with distilled water. In addition, Fourier transform-infrared(FT-IR) spectra showed that C–H bond(methyl group), C–O bond from phenolic alcohol and C–O bond from tertiary alcohol in lignin and holocellulose were involved in TMA adsorption. Coir pithbased filter showed high TMA adsorption efficiency(98%) and kept constant for more than48 days in a continuous system. Pilot scale experiment, coir pith beads filter could be succesfully applied as a packing material for TMA removal. Therefore, coir pith can be used as a promising packing material for TMA treatment at contaminated site.     

北京密闭式垃圾清洁站内外大气监测与安全距离

以北京海淀区为例,对密闭式垃圾清洁站的分布及内外部的大气状况进行了监测并运用大气扩散模型探讨了垃圾清洁站的安全防护距离.结果表明:海淀区垃圾清洁站的分布不均衡;所有垃圾清洁站内外的大气污染物中,H2S、NH3、S02、N02、二硫化碳、苯乙烯、TSP、CO等指标均符合中国相关排放标准;转运站内部三甲胺、甲硫醇、甲硫醚、...     

A/O膜生物反应器处理高浓度氨氮废水试验研究

对A/O膜生物反应器处理高浓度氨氮废水进行了研究,着重考察硝化液回流比和C/N对系统脱氮效能的影响.研究表明,当硝化液回流比为2、C/N为6时.系统对COD、氨氮、TN的平均去除率分别达96.17%、97.76%、76.29%;A/O膜生物反应器稳定运行期间,氨氮容积负荷去除量与进水氨氮容积负荷呈现良好的线性关系;当A/O膜生物反应器内MLSS稳定在9～13 g/L时,上清液COD较低,膜压差增长缓慢.     

基于CFD的污泥脱水机房恶臭扩散分布规律研究

污泥脱水机房是污水处理厂恶臭污染最严重的处理单元之一,其恶臭污染危害工作人员和周边居民身体健康。为研究脱水机房恶臭扩散分布规律,运用计算流体动力学（computational fluid dynamics, CFD）理论并采用其商用软件FLUENT对脱水机房主要恶臭污染物之一的硫化氢扩散分布进行数值模拟。案例研究了3种典型情景下的硫化氢扩散分布。结果表明,不同通风条件对脱水机房硫化氢扩散分布影响较大。在进行脱水机房设计时,应将脱水机布置于夏季最多风向的下方向,并靠近排风口,使恶臭污染物在最短的路径上排除出去,还应考虑机房其他布置,使工作人员经常接触和经过的地方位于低浓度区。     

COD浓度和进水流量比对一体化工艺脱氮除碳的影响

保持进水总流量不变,以一定流量比同时从缺氧区和厌氧区进水,探讨了不同进水流量比(R=Q_厌/Q_缺)和进水COD浓度对中心岛式一体化OCO工艺脱氮除碳的影响。研究结果表明,进水COD浓度和进水流量比Rs对COD的去除效果影响不大,出水COD浓度一直稳定在50 mg/L以下,去除率在92%以上;进水COD浓度和进水流量比Rs共同决定着系统TN的去除效果,进水COD浓度为100 mg/L、200 mg/L时,TN去除率随着进水流量比Rs的减小呈增加的趋势;当进水COD浓度为 300 mg/L时,TN去除率随着进水流量比Rs的减小呈先升高后降低的趋势,在进水流量比Rs为3∶1时TN去除率最高,达到87%。     

Adsorption of Reactive Dye on Chitin

The adsorption of reactive dye on chitin has been investigated with a view to obtain the design data for batch processing of effluents for dye adsorption. The effect of several factors governing the dye adsorption such as the adsorbent concentration, adsorbent size, temperature and pH have been elicited. Desorption of the dye at different temperatures and pH have also been investigated.     

Nest separation and the dynamics of the Gestalt odor in the polydomous ant Cataglyphis iberica (Hymenoptera, Formicidae)

In the polydomous ant species Cataglyphis iberica, nests belonging to the same colony are completely separated during hibernation. In order to examine whether this separation induces changes both in the hydrocarbon profile and in recognition ability between adult nestmates, we separated groups of workers for several months under two different conditions: at hibernation temperature and at room temperature. At room temperature, recognition remained unchanged but separation led to longer mutual antennations relative to non-separated controls. When half of a colony was placed under hibernation conditions, antennal interactions also increased in duration and a few aggressive interactions emerged between separated ants. This aggressiveness never reached the intercolonial level observed in this species. In both cases, the hydrocarbon profiles showed differences between individuals after separation while remaining homogeneous within each nest. This chemical modification may induce the longer antennations observed. After separated groups were reunited, individuals recovered their previous antennation pattern and a convergence in hydrocarbon profiles was again observed. These concurrent observations suggest that hydrocarbons are transferred between nestmates. In C. iberica, the formation of the colonial odor seems to follow the “Gestalt” model which allows all satellite nests of a colony to have a common colonial odor. In the field, temporary nest isolation during hibernation may induce divergence between satellites. The role of adult transport in connecting nests during the active season to obtain an efficient Gestalt odor is discussed. Received: 16 June 1997 / Accepted after revision: 25 October 1997     

电除尘器改造为电袋复合除尘器的实践

介绍了扬子热电厂1~7号炉电除尘器改造为电袋复合除尘器的工程实践,分析了电袋复合除尘器的关键技术及运行情况。改造后,电袋复合除尘器出口烟尘浓度≤30mg/m3,满足排放要求。