Molecular characterization of root exudates using Fourier transform ion cyclotron resonance mass spectrometry

The release of root exudates (REs) provides an important source of soil organic carbon. This work revealed the molecular composition of REs of different plant species including alfalfa (Medicago sativa L.), bean (Phaseolus vulgaris L.), barley (Hordeum vulgare L.), maize (Zea mays), wheat (Triticum aestivum L.), ryegrass (Lolium perenne L.) and pumpkin (Cucurbita maxima) using electrospray ionization coupled with Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS). The combination of positive ion mode (+ESI) and negative ion mode (-ESI) increased the number of the molecules detected by ESI FT-ICR MS, and a total of 8758 molecules were identified across all the samples. In detail, lipids and proteins and unsaturated hydrocarbons were more easily detected in +ESI mode, while aromatic compounds with high O/C were readily ionized in -ESI mode, and only 38% of the total assigned formulas were shared by -ESI and +ESI modes. Multivariate statistical analysis of the formulas indicated that the close related plants species secreted REs with similar molecular components. Moreover, the unsaturation degree and nitrogen content were the two key parameters able to distinguish the similarities and differences of molecular components of REs between plant species. The results provided a feasible analysis method for characterization of the molecular components of REs and for the first time characterized the molecular components of REs of a variety of plant species using ESI FT-ICR MS.     

光催化技术在功能性空气过滤材料中的应用研究

针对目前气态污染物和气溶胶态污染物对人们生活健康产生的巨大危害,论述了目前国内外光催化技术在功能性空气过滤材料中的研究,阐述了光催化技术和纤维过滤技术的基本原理,并对光催化剂在纤维上的负载和应用做了详细介绍,最后提出了该领域可能的发展方向。     

对印染污水的吸滤—焚烧处理研究

吸滤—焚烧法是一种“以废治废”，高效、经济、省时、节能的方法。它用高炉烧煤产生的煤渣、粉煤灰、烟尘吸滤印染污水中的染料、浆料、助剂、色质、异味等物质；用煤燃烧时产生的酸性气体（ＳＯ２、ＣＯ２、ＮＯ２等）中和印染污水中的碱性物质；焚烧吸滤处理印染污水后的煤渣、粉煤灰、烟尘及其吸附的有机物达到处理废物、节约能源的目的。     

Calcium protects roots of Sedum alfredii H. against cadmium-induced oxidative stress

Sedum alfredii is a well-known Cd (cadmium) hyperaccumulator native to China. The impacts of exogenous Ca on Cd-induced oxidative stress and antioxidant systems in roots of S. alfredii were investigated by using cellular and biochemical approaches. Supplementation of the medium with higher Ca levels resulted in alleviated growth inhibition and decreased Cd concentration, as well as increased Ca concentration in roots. Cadmium induced lipid peroxidation and loss of plasma membrane integrity, reactive oxygen species overproduction, as well as ultrastructural changes of root cells were largely reversed by Ca supplementation in the medium. Calcium application significantly altered the Cd effects on antioxidant enzymes and non-enzyme antioxidants (non-protein thiols), and significantly increased glutathione (GSH) biosynthesis. The results suggest that Ca is able to protect the roots of S. alfredii against Cd toxicity by restoration of Cd-displaced Ca, alleviation of the metal induced oxidative stress, as well as promotion of GSH biosynthesis.     

有序介孔材料过滤脱除纳米颗粒物

多孔材料过滤去除环境纳米颗粒物(nanoparticles,NPs)是空气净化治理的重要方法之一.本文采用介孔分子筛(MCM-41、SBA-15)和有序介孔碳(CMK-3)这3种典型介孔材料对2~20 nm的NPs进行过滤脱除研究,旨在探索介孔材料在NPs过滤方面的应用可行性与相关理论基础.基于3种介孔材料的物理化学性质表征结果,通过本实验发现介孔材料孔道的最可几孔径以及一定量的介孔孔容是吸附NPs的关键,而微孔分布对去除NPs贡献不大.进一步对SBA-15在不同流量及不同颗粒床厚度下对NPs的去除进行了分析,发现纳米颗粒物的最易穿透粒径(most penetrating particle size,MPPS)随着流量的增大而减小,同时MPPS颗粒物的去除效率随之降低,且MPPS基本不受颗粒床厚度变化的影响.本研究为介孔材料过滤脱除NPs提供了技术依据.     

电絮凝-膜过滤技术处理含铜废水的研究

为了有效控制重金属废水对环境的污染,采用电絮凝-膜过滤技术处理含铜废水,考察了进水pH、电极电流密度和水流量对铜去除率的影响。结果表明:该技术的最佳进水pH值为5.8,电极电流密度为10 A/m2,水流量为2 L/min。在此条件下,对不同浓度的含铜废水进行处理,铜去除率均在95%以上,最高可达99.02%。由此可见,电絮凝-膜过滤技术对含铜废水具有良好的处理效果。     

The effect of coupling coagulation and flocculation with membrane filtration in water treatment： A review

Water supply and sanitation demands are foreseen to face enormous challenges over the coming decades to meet the fast growing needs in a global perspective. Significant growth in the industry is predicted and membrane separation technologies have been identified as one of the possible solutions to meet future demands. Application and implementation of membrane technology is expected both in production of potable water as well as in treatment of wastewater. In potable water production membranes are substituting conventional separation technologies due the superior performance, potential for less chemical use and sludge production, as well as the potential to fulfill hygienic barrier requirements. Membrane Bio-Reactor (MBR) technology is probably the membrane process which has had most success and has the best prospects for the future in wastewater treatment. Trends and developments indicate that this technology is becoming accepted and is rapidly becoming the best available technology (BAT) for many wastewater treatment applications. A major drawback of MBR systems is membrane fouling. Studies have shown that fouling mitigation in MBR systems can potentially be done by coupling coagulation and flocculation to the process.     

Conditioning of sewage sludge by Fenton's reagent combined with skeleton builders

Physical conditioners, often known as skeleton builders, are commonly used to improve the dewaterability of sewage sludge. This study evaluated a novel joint usage of Fenton’s reagent and skeleton builders, referred to as the F-S inorganic composite conditioner, focusing on their efficacies and the optimization of the major operational parameters. The results demonstrate that the F-S composite conditioner for conditioning sewage sludge is a viable alternative to conventional organic polymers, especially when ordinary Portland cement (OPC) and lime are used as the skeleton builders. Experimental investigations confirmed that Fenton reaction required sufficient time (80 min in this study) to degrade organics in the sludge. The optimal condition of this process was at pH = 5, Fe²⁺ = 40 mg g⁻¹ (dry solids), H₂O₂ = 32 mg g⁻¹, OPC = 300 mg g⁻¹ and lime = 400 mg g⁻¹, in which the specific resistance to filtration reduction efficiency of 95% was achieved.     

生态混凝土净水新技术

介绍了用生态混凝土多层次多反复地降解和消除污染物质的污水处理方法，采用侧滤，首先对污水进行预处理，去除固体悬浮物质后，再经过推流式生态混凝土水处理装置，达到污水净化的目的；其次，通过在生态混凝土中掺加缓释性净水材料，提高了生态混凝土的净水效果和耐久性。     

纤维层表面非稳态过滤研究

根据纤维层表面过滤的“尘滤尘”现象 ,应用颗粒过滤理论建立了纤维层表面非稳态过滤效率的数学模型。对比研究表明该模型能较深刻地揭示了非稳态过滤过程随过滤时间的变化规律 ,从而对深化纤维过滤器的净化机理的认识、提高过滤效率、延长滤料使用寿命、加强清灰管理等方面有理论及应用意义