低pH生物滤池处理甲苯废气

采用低pH生物滤池处理甲苯废气。实验结果表明,低pH生物滤池对甲苯有较好的去除效果,当甲苯废气进气流量为420L/h、进气甲苯质量浓度为200~700mg/m3时,稳定运行阶段,甲苯平均去除效率在98%以上,出气甲苯质量浓度为0~30mg/m3。低pH生物滤池中,CO2的产生量与甲苯降解量的比(物质的量比)为2.60,小于理论值3.35。经过长时间运行,低pH生物滤池内的优势微生物由刚开始接种时的以异养细菌为主演变为真菌为主,优势真菌菌株分别属于白地霉(Geotrichum candidum)、产黄青霉(Penicillium chrysogenum)和黑曲霉(As-pergillus niger)。优势异养细菌为恶臭假单胞菌(Pseudomonas putida)。     

基于物元理论的自然灾害损失等级划分方法

基于"灾度"概念及其改进算法,结合物元理论,提出了自然灾害损失等级划分的可拓学算法,建立了基于物元理论的自然灾害损失等级划分模型,将物元分析方法应用于自然灾害损失等级划分,作为灾害损失等级评估方法的一种补充,并与之前算法互为验证.不仅论证了物元理论应用于灾害等级划分的可行性,阐述了自然灾害损失评估物元模型的算法过程,而且利用该模型正确评估了2008年中国南方冰冻灾害的损失等级.经过反复验证,证实了该方法的科学性,同时提出了该模型尚存在的细节问题,如灾度上限的取值,权重确定的方法等问题,以便于更好的完善该模型算法.     

Effects of chemical oxidation on sorption and desorption of PAHs in typical Chinese soils

In situ chemical oxidation is a commonly applied soil and groundwater remediation technology, but can have significant effects on soil properties, which in turn might affect fate and transport of organic contaminants. In this study, it was found that oxidation treatment resulted mainly in breakdown of soil organic matter (SOM) components. Sorption of naphthalene and phenanthrene to the original soils and the KMnO₄-treated soils was linear, indicating that hydrophobic partitioning to SOM was the predominant mechanism for sorption. Desorption from the original and treated soils was highly resistant, and was well modeled with a biphasic desorption model. Desorption of residual naphthalene after treating naphthalene-contaminated soils with different doses of KMnO₄ also followed the biphasic desorption model very well. It appears that neither changes of soil properties caused by chemical oxidation nor direct chemical oxidation of contaminated soils had a noticeable effect on the nature of PAH-SOM interactions.     

乙烯废碱液的再生

开发了除油-苛化-脱硫组合技术处理乙烯废碱液工艺,考察了影响各级处理效果的主要因素.实验结果表明:经石英砂-聚丙烯腈纤维膜-强碱性阴离子交换树脂组合装置除油后,碱液中油类物质质量浓度小于2 mg/L,NaOH,Na_2CO_3,Na_2S等无机组分含量基本不变;经苛化-脱硫处理后碱液中Na_2CO_3和Na_2S质量浓度分别小于4 430 mg/L和4 480 mg/L;再生碱液的流体力学性质及对酸性气体的吸收性能均可满足乙烯裂解气碱洗要求.     

Catalytic oxidation of gaseous PCDD/Fs with ozone over iron oxide catalysts

Catalytic oxidation of PCDD/Fs (polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans) with ozone (catalytic ozonation) over nano-sized iron oxides (denoted as FexOy) was carried out at temperature of 120-180 degrees C. The effects of operating temperature, ozone concentration, space velocity (SV) and water vapor contents on PCDD/F removal and destruction efficiencies via catalytic ozonation were investigated. High activity of the iron oxide catalyst towards PCDD/F decomposition was observed even at low temperatures with the aid of ozone. The PCDD/F removal and destruction efficiencies achieved with FexOy/O3 at 180 degrees C reach 94% and 91%, respectively. In the absence of ozone, the destruction efficiencies of all PCDD/F congeners are below 20% and decrease with increasing chlorination level of PCDD/F congener at lower temperature (120 degrees C). However, in the presence of ozone, the destruction efficiencies of all PCDD/F congeners are over 80% on FexOy/O3 at 180 degrees C. Higher temperature and ozone addition increase the activity of iron oxide for the decomposition of PCDD/Fs. Additionally, in the presence of 5% water vapor, the destruction efficiency of the PCDD/Fs is above 90% even at lower operating temperature (150 degrees C). It indicates that the presence of appropriate amount of water vapor enhances the catalytic activity for the decomposition of gas-phase PCDD/Fs.     

钢筋混凝土结构构件局部地震损伤多尺度监测方法

提出一种结构局部地震损伤过程的多尺度监测方法。首先,在混凝土材料尺度上,针对混凝土材料细观随机性影响问题,基于压电智能骨料进行混凝土压应力监测,通过试验方法建立了混凝土损伤全过程中压电智能骨料应力与混凝土宏观应力的概率统计关系;其次,在截面尺度上,基于MEMS倾角仪转动监测方法,提出混凝土压弯构件截面曲率的监测方法,并通过试验验证了该方法的可行性;最后,在构件尺度上,提出基于转动积分的层间变形监测方法并给出了转动监测位置的设计原理,通过构件试验验证了该监测方法的可靠性。     

复合重金属污染高岭土的电动修复

根据电子废弃物拆解场地的污染特征,以复合重金属(Cu,Cd,Pb)污染高岭土为研究对象,考察了电动技术对污染土壤的修复效果。实验结果表明:在电压梯度为1 V/cm、阳极液为自来水、阴极液为柠檬酸-柠檬酸钠缓冲液(pH=5)、靠近阴极设置活性炭渗透反应墙(PRB)的条件下电动修复96 h后,Cu,Cd,Pb的平均去除率分别可达79.93%,99.43%,39.36%;土壤的酸碱性对电动修复效果影响显著,通过在阴极添加缓冲液维持土壤偏酸性条件,有利于重金属污染物的电动去除;在靠近阴极设置活性炭PRB可富集重金属,减少阴极液的污染;迁移率大的酸可提取态重金属较易去除,残渣态重金属稳定性强,去除率较低。     

氮肥与DCD配施对棚室黄瓜土壤NH3挥发损失及N2O排放的影响

以传统水氮管理为对照,进行了优化水氮管理条件下氮肥与DCD配施对大棚黄瓜土壤氨挥发损失及氧化亚氮排放的影响研究.试验结果表明,与传统水氮管理相比,优化水氮管理减少了氮肥用量及灌水量,但黄瓜产量并没有降低.各水氮处理的NH3挥发速率峰值出现在施肥灌水后的第3d,添加DCD的各优化水氮处理与传统水氮处理相比,土壤氨挥发累积量分别减少55.97%、43.68%、66.47%,4次追肥后W2N2+DCD、W2N3+DCD和W2N4+DCD的氨挥发速率峰值与累积量变化范围较小.不同水氮处理的N2O排放通量的峰值均出现在施肥灌水后的第4d,各追肥时期W2N2+DCD、W2N3+DCD和W2N4+DCD处理,土壤N2O排放通量峰值与N2O累计排放量均显著低于传统水氮处理W1N1,并且3个处理之间不存在显著差异,充分表明优化水氮管理中将氮肥与DCD配施对减少N2O排放起到了显著作用.     

问策老庄——生态治理的道家智慧

老庄道家思想蕴含着丰富的生态智慧,前人的研究为其在生态治理中"致大用"提供了现实举证与理论观点。老庄思想中辩证的"反向性"有助于生态危机面前人类的自我反省,其"道"的"本根性"有助于引领生态治理走向最佳路径。当前生态治理存在主体松散化、客体碎片化、政府治理单边化、生态公正边缘化、生态修复人工化的困局。老庄道家思想为我们提供了具有针对性的行为准则。生态治理主体应具有"以天下观天下"的大智慧、大胸襟,生态问题防御要以"正反相随、祸福相依"的观念总揽根源,政府要善用"无为"来调动生态环境的社会共治,生态公正需要树立"以小为大"的价值观,生态修复需要树立"辅万物之自然"的生存理念。     

Isolation and characterization of Sporobolomyces sp. LF1 capable of degrading chlorimuron-ethyl

A yeast strain which was capable of degrading sulfonylurea herbicide chlorimuron-ethyl named as LF1 was isolated from a chlorimuron-ethyl contaminated soil near the warehouse of the factory producing chlorimuron-ethyl in Shenyang City, Northeast China. The strain was identified as Sporobolomyces sp., based on its morphological and physiological characteristics and the phylogenetic analysis of 18S rRNA gene sequence. So far, this is the only yeast strain of Sporobolomyces sp. which is able to degrade chlorimuronethyl. Incubation tests showed that when the initial concentration of chlorimuron-ethyl in culture was 5 mg/L, LF1 could degrade more than 77% of the herbicide after incubation for 4 d at 30°C. The possible mechanism of chlorimuron-ethyl degradation by LF1 could be the acidic hydrolysis caused by the acids from the metabolism of the yeast strain. Further study should be conducted to examine the pathways of chlorimuron-ethyl degradation by LF1 and to approach the feasibility of using LF1 to degrade the chlorimuron-ethyl in soil system.