磁混凝对市政污水中抗生素抗性基因和重金属抗性基因的削减效能

污水中抗性基因给环境和人类健康带来潜在的危害.本研究通过调查市政排口污水磁混凝处理过程中抗性基因绝对含量和相对丰度变化,考察磁分离技术对市政污水中抗性基因的削减效果.结果表明,加入磁种和絮凝剂的一级搅拌和二级搅拌对抗生素抗性基因(ARGs)、重金属抗性基因(MRGs)和可移动遗传元件均有较好地去除效果,但出水中部分抗性基因的绝对含量增加,这可能是由于出水中依然具有较高含量的水平转移元件(int1,2. 00×10¹⁰ copies·mL^-1; int2,1. 91×10⁸ copies·mL^-1; Tn916/1545e,5. 38×10⁸ copies·mL^-1).网络分析和主成分分析结果表明,磁混凝处理过程中ARGs与MRGs呈显著正相关(P <0. 05),城市污水中常规污染物如悬浮物、磷和COD等是影响抗性基因去除效率的重要因子.这些结果表明,磁混凝可通过有效削减污水中常规污染物进而制约抗性基因的传播和转移;但需要关注磁混凝的出水及脱水污泥的...     

基于高压挤压预处理的生活垃圾干湿分离处理工艺不同场景综合效益分析

目前，生活垃圾分类已经在我国逐渐成为一种"新风尚"，但现阶段以厨余组分为代表的湿垃圾和可燃组分为代表的干垃圾分离效率仍然有限，使得后端生物处理技术难以高效运行，同时也降低了垃圾焚烧厂的能源回收率，这些问题已成为制约我国生活垃圾分类持续推进的瓶颈.本文在前期对高压挤压预处理的研究基础上，利用生命周期清单分析的方法，从温室气体排放、净能源产生、污染物释放、资源回收和垃圾减量等方面，对高压挤压预处理后"湿垃圾厌氧消化+沼渣填埋+干垃圾焚烧发电"、"湿垃圾厌氧消化+沼渣土地利用+干垃圾焚烧发电"和"混合垃圾焚烧"3种处理场景开展对比分析，评估3种场景的综合环境效益，阐明预处理作用与意义.结果表明，处理每吨原生垃圾，两种基于高压挤压预处理的生活垃圾干湿分离处理场景可分别减排温室气体218.84和264.08 kgCO₂-Eq，远高于混合垃圾焚烧工艺（169.68 kgCO₂-Eq）；在净能源产生方面，两种干湿分离处理场景较混合垃圾焚烧场景约少10%，但同样会削减焚烧过程产生的有毒污染物.此外，利用"湿垃圾厌氧消化产生的沼渣进一步脱水后进行土地利用"这一场景处理每吨生活垃圾，不仅能够实现约160.7 kg的资源回收，而且垃圾整体减量率达到93.4%，是一种适合我国国情的垃圾处理方式.     

VxMn(4 − x)Mo3Ce3/Ti catalysts for selective catalytic reduction of NO by NH3

A series of vanadium based catalysts(VxMn(4-x)Mo3Ce3/Ti) with different vanadium(x wt.%) and manganese((4-x) wt.%) contents have been prepared by the wet impregnation method and investigated for selective catalytic reduction(SCR) of NO_x by NH_3 in the presence of 8 vol.% H_2O and 500 ppm V SO_2.The physicochemical characteristics of the catalysts were thoroughly characterized.The SCR of NO_x by NH_3(NH_3-SCR) activity, especially the low-temperature activity, significantly increased with increasing V_2O_5 content in the catalyst until the V_2O_5 content reached 1.5 wt.%, which corresponds well with the redox properties of the catalyst.All of the metal oxides were well dispersed and strongly interacted with each other on the catalyst surface.V mainly exists in the V~(5+)state in the catalysts.The strong synergistic effect between the vanadium and cerium species led to formation of more Ce~(3+)species, and that between the vanadium and manganese species contributed to formation of more manganese species with low valences.All of the catalysts exhibited strong acidity, while the redox properties determined the NH_3-SCR activity, especially the low-temperature activity.H_2O and SO_2 had severe inhibiting effects on the activity of V1.5Mn2.5Mo3Ce3/Ti.However, good H_2O and SO_2 resistance and high NO_x conversion by V1.5Mn2.5Mo3Ce3/Ti could be achieved in the presence of SO_2 and almost no decline was observed in a long-term test at 275℃ for 168 hr in the presence of SO_2 and H_2O, which can be attributed to the sulfate species formed on the catalyst surface.     

Process safety aspects in water-gas-shift (WGS) membrane reactors used for pure hydrogen production

The syngas produced by coal gasification processes can be utilized in Pd-based water-gas-shift membrane reactors for the production of pure H₂. Pd/alloy composite membrane reactors exhibit comparative advantages over traditional packed bed reactors such as simultaneous reaction/separation in one compact unit and increased reaction yields. Furthermore, the development of comprehensive process intensification strategies could further enhance membrane reactor performance resulting in a substantially smaller and functional, inherently safer, environmentally friendlier and more energy efficient process.A systematic non-isothermal modeling framework under both steady state and dynamic/transient conditions for a catalytic high temperature water-gas shift reaction in a Pd-based membrane reactor has been developed to characterize the dynamic behavior of the process system at various operating conditions from a process safety standpoint. In particular, various reaction conditions as well as key process variables such as feed temperature and flow rate, catalyst loading, driving force for H₂ permeation are considered as they are critically related to various safety aspects in the operation of a Pd-based membrane reactor. Within the proposed framework, process parameters and operating conditions which may induce hazards and compromise process safety are identified, analyzed and characterized. Finally, the proposed approach is evaluated through detailed simulation studies in an illustrative case study involving a real Pd-based membrane reactor used for pure hydrogen production and separation that exhibits complex behavior over a wide operating regime.     

应用高梯度磁分离技术处理糖蜜酒精废水

采用投磁种的方法进行强化，高梯度磁分离技术可以有效地用于处理有机工业废水，废水经处理后其浊度、色度和ＣＯＤ都大大降低．系统地研究了这一新方法应用于处理糖蜜酒精废水以及磁种再生的全过程，探讨了磁种的活性、处理效果及其影响因素．结果表明，废水磁种强化磁分离处理过程主要是一个ｐＨ控制过程，最佳处理ｐＨ值为５左右，磁种再生ｐＨ值为１１左右．     

燃煤脱硫磁分离技术的研究与应用

概述了高梯度磁分离技术在燃煤脱硫除灰方面的应用与研究进展，以及超导磁分离技术在燃煤脱硫方面的研究，并展望了超导磁分离技术在环境保护中的应用前景。     

福州明达电厂油污水处理系统改造工程的特点与分析

主要介绍福州明达电厂油污水处理系统改造工程的基本情况，试运行效果和经济效益等。     

我国合成洗涤剂生产废水治理技术研究

综述了近年来我国合成洗涤剂生产废水的特性;化学混凝法、泡沫分离法和生物接触氧化法处理合成洗涤剂生产废水的最佳工艺条件及其处理效果;工程应用实例及经济分析等。生产运行结果表明,处理后出水水质全面达到国家排放标准。化学混凝法,泡沫分离一混凝法其设备、流程简单、去除效率高、占地少,但运行费用较高。生物接触氧化－臭氧氧化法其出水可以回用、工艺先进、可靠、运行费用低、无二次污染。     

处理含油污水的水力旋流器

介绍了水力旋流器的基本结构、工作原理、影响水力旋流器分离性能的因素及应用研究进展。     

高梯度磁分离技术在饮用水处理中的研究与应用

概述了国内外对高梯度磁分离技术在饮用水处理中的研究应用状况及其优点，并展望了该技术在饮用水处理中的应用前景。