天然沸石与泥炭脱氮除磷实验研究

设计并构建了天然沸石与泥炭生物滤池装置,实验考察其在微污染景观水中脱氮除磷性能,研究其形成生物膜系统后对污染物去除的机理及效果。结果表明：该装置具备良好的生物去除污染物效果,运行稳定后CODcr、NH4＋-N和TP去除率分别可达80%、95%和41%;通过生物作用可使天然沸石与泥炭再生,实现材料持续使用。     

泥炭与沸石制取吸附材料实验研究

利用天然沸石和泥炭作为原材料,水泥作为粘结剂,研制出一种具有一定强度并同时具有脱氮除磷功能的新型吸附材料.实验结果表明:天然沸石∶天然泥炭∶水泥质量比为=2∶0.05∶1时,该材料抗压强度可达6.79 MPa,耐水性能良好.材料吸附性能实验结果揭示,该材料对氨氮和总磷具有良好的去除效果,符合准二级动力学模型.     

现代污水处理生物脱氮除磷工艺分析

概述生物脱氮除磷机理,包括生物脱氮、生物除磷机理以及同步脱氮除磷机理、反硝化脱氮除磷机理。分析不同生物脱氮除磷机理的处理工艺,并阐述了脱氮除磷工艺的发展趋势。     

污水生物除磷脱氮新技术探讨与展望

概述了传统的生物除磷脱氮的基本原理与局限性,并介绍了新的除磷脱氮理论及典型工艺,指出反硝化除磷脱氮技术是未来污水生物处理可持续的发展方向。     

污泥制取新型环保合成材料实验研究

以微波处理后城市污水厂污泥、天然沸石和水泥为原材料,不进行任何改性,研制一种既具有脱氮除磷功能,又具备抗压强度,并可在水体中保持一定形态的低能耗新型环保合成材料。实验结果表明:水泥:天然沸石:污泥的质量比为1:2:0.05,合成材料的耐水性能良好,7 d的抗压强度为5.8 MPa,对氨氮、总磷的吸附量分别可达到229.8 mg·kg-1以及321.4 mg·kg-1,且符合准二级动力学模型。     

SBR法处理城市污水脱氮除磷的影响因素研究

随着城市的发展和工业化进程的加快,水体富营养化日趋严重。污水中的氮、磷的去除已成为污水处理的热点。生物脱氮除磷工艺在脱氮除磷中广泛应用。介绍和分析SBR法脱氮除磷的原理以及通过对各影响因素(进水方式,曝气时间,污泥浓度,进水时间,C/N比,C/P比)的研究实验,深入探讨了SBR对于城市污水脱氮除磷的重要性。     

泥炭在水处理中除磷研究进展

基于非金属矿物材料泥炭空隙率大、比袁面积大、吸附能力强、分子结构中存在多种活性官能团,以及具有较强的离子交换和络合能力等特点,探讨泥炭在水处理中除磷的机理,分析水处理中采用泥炭、改性泥炭除磷的研究进展,为泥炭、改性泥炭及生物膜形成后的再生泥炭在水处理中的应用提供理论和技术支撑.     

水生植物千屈菜夏季生理变化及其脱氮除磷实验研究

研究了千屈菜在夏季微污染水体中的生理特性日变化规律和脱氮除磷净水效果.在三种不同栽植密度的净水槽中,分别考察了千屈菜根系POD活性、根系活力、Ch1a和Ch1b含量以及水体中NH4+-N、TP和CODcr污染物浓度等指标,分析了植物生理特性日变化规律及其与脱氮除磷性能和栽植密度之间的关系.结果表明:根系POD活性、根系...     

吸氮除磷材料的研究进展

氮和磷是地表水体中比较受关注的两种污染物,生活污水过量排入河湖等地表水体中,将引起水体富营养化.着重阐述了改性后的矿物型和非矿物型材料在吸氮除磷方面的研究进展,在此基础上,对其在水处理领域的应用前景进行了展望,认为结合现代先进的化学技术对环境友好型材料进行改性,开发高效的环境友好型材料,对于同步去除水体中氮磷具有重要意...     

反硝化除磷理论及其影响因素分析

综述传统生物除磷机理及反硝化除磷机理,并分析反硝化除磷的影响因素和未来发展新思路。     

改性前后沸石及其再生脱氮效果对比分析

基于天然沸石的结构及其组成成分,阐述了天然沸石脱氮性能、改性方法及改性沸石脱氮性能、再生方法及其再生沸石脱氮性能,综合对比分析了天然沸石、改性沸石和再生沸石的脱氮效果。结果表明,利用天然沸石进行生物再生并循环利用,不仅节能、避免产生二次污染,又能要脱氮的同时去除其它污染物,而且可长期使用,是一种处理微污染水体的新方法,从而为解决水环境富营养化问题提供了新的思路。     

Passive heat and moisture removal from a natural vented enclosure with a massive wall

Simultaneous transport of heat and moisture by conjugate natural convection in a partial enclosure with a solid wall is investigated numerically. Moist air motions are driven by the external temperature and concentration differences imposed across enclosures with different ambient moisture conditions. The Prandtl number and Schmidt number used are 0.7 and 0.6, respectively. The fluid, heat and moisture transports through the cavity and solid wall are, respectively, analyzed using the streamlines, heatlines and masslines, and the heat and mass transfer potentials are also explained by the variations of overall Nusselt and Sherwood numbers. The numerical simulations presented here span a wide range of the main parameters (heat and mass diffusion coefficient ratios, solid wall thickness and thermal Rayleigh numbers) in the domain of aiding and opposing buoyancy-driven flows. It is shown that the heat transfer potential, mass transfer potential, and volume flow rate can be promoted or inhibited, depending strongly on the wall materials and size, thermal and moisture Rayleigh numbers.     

Commercial process for mass production of synthetic natural gas through the adiabatic reactors: operational characteristics of a 50‐kW pilot‐plant,influence of steam,and CO2

In synthetic natural gas (SNG) reaction process, the water gas shift (WGS) reaction and methanation reaction take place simultaneously, and an insufficient supply of steam might deactivate the catalyst. In this study, the characteristics of the methanation reaction with a commercial catalyst and using a low [H₂]/[CO] mole ratio in SNG synthesis are evaluated. The reaction characteristics at various possible process parameters are evaluated varying different process parameters such as the [H₂O]/[CO] mole ratio, [H₂]/[CO] mole ratio, flow of different % CO₂, and reaction temperature. Temperature profiles on catalyst bed are monitored as a function of the [H₂O]/[CO] mole ratio, [H₂]/[CO] mole ratio, and flow of different % CO₂. Through a lab‐scale optimization process, suitable optimum conditions are selected and in the same condition a 50‐kW pilot‐scale SNG production process through adiabatic reactors is carried out. The pilot scale SNG reaction is stable through overnight and the CO conversion efficiency and CH₄ selectivity are 100% and 97.3%, respectively, while the maximum CH₄ productivity is 0.654 m³/kg_cat · h. Copyright © 2016 John Wiley & Sons, Ltd.     

Influence of undulating wall heat and mass flux on MHD natural convection boundary layer flow from a vertical wall

Current study expounds an unsteady magnetohydrodynamic natural convective flow along a vertical wall in presence of variable transverse magnetic field. Small amplitude undulation in wall heat flux and wall mass flux are imposed at the vertical wall to generate the boundary layer flow. The flow governing equations are divided into sets of steady and unsteady equations and then transformed into the similarity and nonsimilarity equations, respectively, by introducing stream function formulations. The sets of nonsimilarity equations are solved numerically by using three different techniques, namely, perturbation solution technique, asymptotic solution technique and implicit finite difference technique applied, respectively, for lower, higher, and all frequencies (ξ). Results are illustrated in connection with the amplitude and phase angles of shear stress, wall temperature, and concentration against the frequency (ξ) for wide ranges of physically significant parameters. Likening of the results obtained by above mentioned numerical methods are presented in every figure and table. Results reveal that the amplitude of undulating shear stress and wall temperature dwindle and the amplitude of wall concentration increases due to increment in Prandtl number (Pr). Besides, on incrementing Schmidt number (Sc) the amplitude of undulating shear stress and wall concentration dwindle and the amplitude of wall temperature increases. Results also reveal that on incrementing magnetic parameter (M) the amplitude of transient shear stress dwindles while the amplitude of transient wall temperature and concentration increase.