Early Responses to Acute Ozone Exposure in Two Fagus Sylvatica Clones Differing in Xeromorphic Adaptations: Photosynthetic and Stomatal Processes, Membrane and Epicuticular Characteristics

Two Fagus sylvatica L. clones were used to investigate the early responses to acute O₃ exposure (150 nL L⁻¹, i.e., 1.35× ambient hourly peak in rural Italy) and whether xeromorphic adaptations affect gas exchange, membrane, and epicuticular responses. One clone originated in a wet and temperate climate in Central Italy (Tuscany); the other clone originated in a warmer and drier climate in the southern-most part of the F. sylvatica distribution (Sicily). Because of higher base gas exchange rates, the most negative effects of O₃ exposure (gas exchange impairment, uncoupling between net photosynthesis and stomatal conductance, increased membrane lipid peroxidation) were found in the southern clone. Xeromorphic adaptations (higher epicuticular waxes and stomatal density, lower leaf wettability and size) were found in this clone. Our results suggest that xeromorphism may increase O₃ sensitivity in species not adapted to face water stress, like the mesophilic F. sylvatica, when experiments are carried out with full irrigation. We present evidence describing the relationship between gas exchange and number and status of stomata. Stomatal density and the structural damage to stomata resulting from O₃ exposure did not affect gas exchange: In fact, non-stomatal limitations to photosynthesis prevailed over stomatal limitations.     

膜生物反应器法处理模拟印染废水

针对人工模拟的印染废水,设计了缺氧/好氧膜生物反应器相结合的处理装置。系统经过165 d的运+行,结果表明:系统对COD和氨氮一直有很好的去除效果,稳定期COD的去除率可以达到95.0%,NH4+-N平均去除率为96.5%,TP的平均去除率低于50%,TN的去除率处在60%⁸0%之间,活性艳红染料X-3B的去除率在60%80%之间,活性艳红染料X-3B的去除率在60%⁷3%之间,出水含有少量色度。水样中长链的壬基酚聚氧乙烯醚NP10EO的去除率可以达到99%,出水仅含有少量的NP1EO,NP2EO和NP。     

膜法处理垃圾渗滤液新技术实验研究

将改进间歇式活性污泥法与FIL-MAX膜组合处理工艺相结合,应用于沈阳某垃圾场垃圾渗滤液处理工程实例中。通过实验,分析了COD、NH3-N等指标的处理效率以及影响因素,最终得出改进间歇式活性污泥法与FIL-MAX组合工艺处理在一定程度上改善膜污染、膜堵塞等常见问题。     

Recent advances in ionic liquids-based hybrid processes for CO2 capture and utilization

CO₂ capture and utilization (CCU) is an effective strategy to mitigate global warming. Absorption, adsorption and membranes are methods used for CO₂ separation and capture, and various catalytic pathways have also been developed for CO₂ utilization. Although widely researched and used in industry, these processes are energy-intensive and this challenge needs to be overcome. To realize further optimization, novel materials and processes are continuously being developed. New generation materials such as ionic liquids (ILs) have shown promising potential for cost-effective CO₂ capture and utilization. This study reviews the current status of ILs-based solvents, adsorbents, membranes, catalysts and their hybrid processes for CO₂ capture and utilization. The special properties of ILs are integrated into new materials through hybridization, which significantly improves the performance in the process of CCU.     

Pre-oxidation enhanced cyanobacteria removal in drinking water treatment: A review

Cyanobacterial bloom has many adverse effects on source water quality and drinking water production. The traditional water treatment process can hardly achieve satisfactory removal of algae cells. This review examines the impact of pre-oxidation on the removal of cyanobacteria by solid-liquid separation processes. It was reported that the introduction of chemical oxidants such as chlorine, potassium permanganate, and ozone in algae-laden water pretreatment could improve algae removal by the subsequent solid-liquid separation processes. However, over dosed oxidants can result in more serious water quality risks due to significant algae cell lysis and undesirable intracellular organic matter release. It was suggested that moderate pre-oxidation may enhance the removal of cyanobacteria without damaging algae cells. In this article, effects of moderate pretreatment on the solid-liquid separation processes (sedimentation, dissolved air flotation, and membrane filtration) are reviewed.     

低温SMBR系统中高粘性膨胀的发生与控制

利用一体式膜生物反应器(SMBR),研究了低温时的高粘性膨胀现象。结果表明:当温度为8℃,SRT为60d时发生了严重的高粘性膨胀。膨胀期间,SMBR对COD的去除并无太大影响,但NH3-N和TN的去除率降低。高粘性膨胀使膜污染速率大大增加,降低了膜清洗周期。通过调整进水配方、增加排泥次数、加大曝气量等方法控制了膨胀现象。     

电厂二氧化碳捕集分离技术研究综述

电厂二氧化碳捕集与封存是二氧化碳减排措施研究热点,也是全球二氧化碳减排的重要任务之一,可分为物理吸附/吸收、化学吸收、物理-化学吸收、膜技术及生物技术等。其中物理吸附/吸收、化学吸收为电厂二氧化碳捕集主流技术。开发具有高选择性、高效率吸收剂及捕集技术,提高能源利用效率,合理布置尾部烟气脱碳处理设施是电厂二氧化碳捕集技术面临的挑战。     

生物加强超滤深度处理城市中水过程膜污染与清洗效果分析

金桥电厂采用生物加强超滤工艺对城市二级排放水进行深度处理,清水用于锅炉循环冷却水补给水。在连续半年的运行期间没有产生严重膜污染情况,通过反洗、在线反洗、鼓风曝气和适当操作条件能很好的防治并预防膜污染,保证系统的稳定运行。     

Liquid balance monitoring inside conventional,Retrofit, and bio-reactor landfill cells

The Outer Loop landfill bioreactor (OLLB) in Louisville, KY, USA has been the site of a study to evaluate long-term bioreactor performance at a full-scale operational landfill. Three types of landfill units were studied including a conventional landfill (Control cell), a new landfill area that had an air addition and recirculation piping network installed as waste was being placed (As-Built cell), and a conventional landfill that was modified to allow for liquids recirculation (Retrofit cell). During the monitoring period, the Retrofit, Control, and As-Built cells received 48, 14, and 213 L Mg^?1 (liters of liquids per metric ton of waste), respectively. The leachate collection system yielded 60, 57 and 198 L Mg^?1 from the Retrofit, Control, and As-Built cells, respectively. The head on liner in all cells was below regulatory limits. In the Control and As-Built cells, leachate head on liner decreased once waste placement stopped. The measured moisture content of the waste samples was consistent with that calculated from the estimate of accumulated liquid by the liquid balance. Additionally, measurements on excavated solid waste samples revealed large spatial variability in waste moisture content. The degree of saturation in the Control cells decreased from 85% to 75%. The degree of saturation increased from 82% to 83% due to liquids addition in the Retrofit cells and decreased back to 80% once liquid addition stopped. In the As-Built cells, the degree of saturation increased from 87% to 97% during filling activities and then started to decrease soon after filling activities stopped to reach 92% at the end of the monitoring period. The measured leachate generation rates were used to estimate an in-place saturated hydraulic conductivity of the MSW in the range of 10^?8 to 10^?7 m s^?1 which is lower than previous reports. In the Control and Retrofit cells, the net loss in liquids, 43 and 12 L Mg^?1, respectively, was similar to the measured settlement of 15% and 5–8% strain, respectively (Abichou et al., 2013). The increase in net liquid volume in the As-Built cells indicates that the 37% (average) measured settlement strain in these cells cannot be due to consolidation as the waste mass did not lose any moisture but rather suggests that settlement was attributable to lubrication of waste particle contacts, softening of flexible porous materials, and additional biological degradation.     

膜生物反应器中膜污染问题讨论

膜生物反应器是近年新发展起来的高效废水处理工艺，同时不可避免地带来了膜的污染问题。本文综述了近年来国内外对膜污染机理研究的最新成果，介绍了相应的解决措施，展望了今后的发展前景。