PKS控制系统在锅炉烟气脱硝处理中的应用

Honeywell PKS控制系统应用于循环流化床锅炉脱硝处理,可实现工艺数据的集中显示和工艺指标的集散控制,特别是在关键设备如稀释风机的互备联锁控制、氨流量的自动调节、吹灰器的顺序控制等方面,利用PKS系统丰富的功能块,实现了控制策略的组态和优化,保证了生产安全稳定运行。     

烧结机烟气选择性脱硫技术的研发与应用

介绍了钢铁工业烧结烟气选择性脱硫技术及循环流化床半干法脱硫工艺的原理、系统运行效．果及在应用中存在的问题，并对其发展提出了建议。     

Evaluation of Selective Culling of Infected Individuals to Control Tasmanian Devil Facial Tumor Disease

Abstract: Sustainable strategies to manage infectious diseases in threatened wildlife are still lacking despite considerable concern over the global increase in emerging infectious diseases of wildlife and their potential to drive populations to extinction. Selective culling of infected individuals will often be the most feasible option to control infectious disease in a threatened wildlife host, but has seldom been implemented or evaluated as a management tool for the conservation of threatened species. The Tasmanian devil (Sarcophilus harrisii) is threatened with extinction by an infectious cancer, devil facial tumor disease (DFTD). We assess the success of an adaptive management trial involving selective culling of infected Tasmanian devils to control DFTD. Demographic and epidemiological parameters indicative of disease progression and impact were compared between the management site and a comparable unmanaged control site. Selective culling of infected individuals neither slowed rate of disease progression nor reduced population‐level impacts of this debilitating disease. Culling mortality simply compensated for disease mortality in this system. Failure of selective culling to impede DFTD progress and reduce its impacts in the managed population was attributed to DFTD's frequency‐dependent nature, its long latent period and high degree of infectivity, and the presence of a cryptic hidden disease reservoir or continual immigration of diseased individuals. We suggest that increasing the current removal rate and focusing removal efforts prior to the breeding season are options worth pursuing for future management of DFTD in this population. On the basis of our experience, we suggest that disease‐management programs for threatened wildlife populations be developed on the principles of adaptive management and utilize a wide variety of strategies with regular reviews and adaptation of strategies undertaken as new information is obtained.     

Direct electrochemical detection of glyphosate at carbon paste electrode and its determination in samples of milk,orange juice,and agricultural formulation

Abstract

This paper describes a simple, inexpensive, highly sensitive, selective, and efficient electrochemical method to determine glyphosate (GLY) in samples of milk, orange juice, and agricultural formulation. The oxidation reaction on the electrode surface was electrochemically characterised by cyclic voltammetry (CV) and square wave voltammetry (SWV). The investigation of GLY at carbon paste electrode revealed a non-reversible oxidation peak at +0.95 V versus Ag/AgCl, which was used for electrochemical detection of GLY. The operating parameters (pH, frequency, step potential, and amplitude) were optimised in relation to the peak current intensity, and a calibration curve was set up in a concentration range of 4.40?×?10^?8–2.80?×?10^?6 mol L^?1, with a detection limit of 2?×?10^?9 mol L^?1. After calibration curve was plotted, the developed procedure was applied to determine GLY in previously contaminated samples: milk and orange juice, and in a commercial formulation, obtaining recovery values between 98.31% and 103.75%. These results show that the proposed method can be used for GLY quantification in different samples with high sensitivity, specificity, stability, and reproducibility.     

Revealing the effect of preparation parameters on zeolite adsorption performance for low and medium concentrations of ammonium

The effect of preparation parameters on the performance of zeolite for ammonium(20–300 mg N/L) adsorption from simulated wastewater is reported. It was found that the ratios of Na_2O/SiO_2 and Si/Al had a more important influence than crystallization time on zeolite adsorption properties. Relatively low Na_2O/SiO_2 ratios were beneficial for fabrication of zeolites with high proportions of micropore area and volume, which led to the surface adsorption mechanism being dominated by surface free energy and pore effects. However,with decreasing Si/Al ratios, the effect of ion-exchange was more prominent due to the high negative surface potential of zeolite. In addition, the concentration of weak acid sites on the zeolites was increased with lower ratios of Na_2O/SiO_2 and Si/Al, which may promote ammonium removal. Therefore, the most effective zeolite for ammonium removal, which was fabricated at Na_2O/SiO_2= 1.375, Si/Al = 4 and crystallization time of 48 hr, exhibited the cooperative effects of adsorption, ion-exchange and a large amount of weak acid sites. The maximum ammonium adsorption capacity(35.06 ± 0.98 mg/g) and the removal efficiency(94.44% ± 4.00%) were obtained at the dosage of 4.0 g/L zeolite NaX at ammonium concentrations of 300 mg N/L and 20 mg N/L, respectively. The Freundlich isotherm and pseudo-first-order kinetics models provided excellent fitting for the ammonium adsorption process. In addition, zeolite NaX showed about 1.23–3.2 times the ammonium adsorption capacity of clinoptilolite. The stable and efficient reusability of zeolite NaX after five regeneration cycles demonstrated that this adsorbent has considerable potential for practical industrial applications.     

化学还原氧化石墨烯修饰PbO2电极及催化降解酸性红G

为了提高Ti/PbO₂电极的稳定性与催化氧化能力,将化学还原氧化石墨烯（RGO）以共沉积的方法修饰于β-PbO₂层.通过扫描电镜（SEM）,X射线衍射仪（XRD）,循环伏安法（CV）,电化学交流阻抗（EIS）,产羟基自由基（·OH）能力,强化寿命等测试方法对电极性能进行表征,并以酸性红G（ARG）为目标降解物,评估PbO₂-RGO电极的催化效果.结果表明,电极经RGO改性后晶型仍为β-PbO₂,析氧过电位由1.60V升至1.83V,膜阻抗由144 Ω/cm²降至16.2 Ω/cm²,强化寿命提升了43.6%.通过ARG降解实验表明,改性后的PbO₂-RGO电极催化性能均有所提高,其中PbO₂-RGO（0.05）电极具有最优的催化能力,120min内对ARG的脱色率可达到98.5%,同时对COD的去除率可达76.89%.     

3DBER系统功能强化与协同作用机制研究

针对污水厂二级生物处理出水C/N低且可生化性差、深度脱氮需外加碳源等问题,结合污水资源化对二级处理出水深度去除TN、TP和微污染物的技术需求,通过改变传统三维电极生物膜工艺（3DBER）的填料组成,构建了强化反硝化脱氮、并具备同步除磷、除微污染物（以邻苯二甲酸二丁酯（DBP）、邻苯二甲酸（2-乙基已基）酯（DEHP）为例,用PAEs表示）功能的3DBER多功能复合反硝化系统,探讨了3DBER工艺强化脱氮同步实现除磷、除微污染物复合功能的技术途径,并从工艺性能、微生物种群分布等角度,深入解析了实现复合功能的技术方法与微观作用机制.结果表明,硫/铁复合功能填料是实现低C/N二级生物处理出水深度脱氮、除磷、除微污染物的关键因素,多功能复合反硝化系统脱氮效率比传统3DBER工艺平均提高20%左右,TP去除率可达80%,PAEs去除率在90%以上.化学计量学和分子生物学技术的分析表明,复合系统脱氮、除磷过程中在微生物生态、电子供体补偿和酸碱度平衡等方面存在协同促进作用.其中,脱氮功能来自异养与多种自养反硝化共同作用,除磷的关键是海绵铁的持续腐蚀,PAEs的去除过程则是吸附、电化学氧化与生物降解协同作用的结果.     

基于硫桥杯[4]芳烃识别金属离子的荧光传感器的研究进展

综述了近些年以硫桥杯[4]芳烃为分子平台的新型荧光传感器的研究进展。详细介绍了不同基团修饰的硫桥杯芳烃衍生物通过非共价键作用力对Hg^2＋,Ag^＋,Fe^3＋,Cu^2＋等金属离子的选择性识别,并设计成不同类别的荧光传感器,以荧光光谱法为手段,进行分析研究。以杯芳烃为主体的荧光传感器具有简便快速、高选择性的特点,广泛应用于化学、生物、环境等领域。     

水蒸气蒸馏-离子选择电极法测定矿冶废水中氟化物

建立了采用水蒸气蒸馏进行预处理,用离子选择电极法测定矿冶废水中的氟化物的方法.实验表明,以硫酸为蒸馏试剂,最佳蒸馏条件为,硫酸用量50 mL,蒸馏温度140 ～150℃,蒸馏时间30 min,方法检出限0.05 mg/L.将该方法用于实际样品分析,测定结果的相对标准偏差为2.0％,加标回收率为93.1％.该方法能够有效...     

Piggery waste treatment by anaerobic digestion and nutrient removal by ionic exchange

Piggery wastes must be treated before their disposal. The high solids content and high chemical oxygen demand of piggery wastes indicated that anaerobic biological treatment could be successfully applied as primary treatment. For that reason, a comparison between upflow anaerobic sludge bed reactor (UASB) and anaerobic fixed bed reactor (AFBR) at a similar organic volumetric loading rate of 5 kg DQO/m³ day was carried out. 60% of the piggery waste COD was removed with the AFBR compared to 40% with the UASB, thus showing a better performance of the AFBR. After 1-h sedimentation secondary process, both anaerobic effluents were treated by ionic exchange with natural zeolite due to their high values of ammoniacal nitrogen (NH⁺₄ plus free NH₃). The high removal of nutrients reported (90%) shows zeolite to be a good choice as tertiary treatment.