氨法在燃煤电厂烟气治理中的应用和发展

燃煤排放的CO2、SO2、NOx等气态污染物会造成酸雨、温室效应、臭氧层破坏等一系列的大气环境问题。减少和抑制燃煤电厂燃烧过程中污染气体的排放，是实现清洁生产和能源可持续发展的基本需要。氨法烟气治理技术作为电厂排放烟气处理的新兴技术，以其污染物脱除效率高、耗能小、二次污染低、脱除副产品可资源化等特点，得到了越来越多的关注，并已在部分燃煤电厂得到成功的应用。对氨法脱除烟气中气态污染物技术进行了分析和总结，并对其应用前景进行了分析和预测，指出了氨法烟气治理技术在燃煤电厂烟气处理方面具有良好的经济、社会和环保效益，并具有广阔的发展前景。     

火电厂脱NOx用SCR催化剂种类及工程应用

介绍了SCR法脱除氮氧化物的催化剂种类,着重介绍了商业用钛基脱硝催化剂和现阶段国内脱硝催化剂的应用情况,讨论了导致催化剂中毒的各种原因,阐述了燃煤电厂应用SCR技术中对催化剂的要求。     

烟气脱硝技术的研究

氮氧化物(NOx)的污染危害是一个不容忽视的问题.目前,我国燃煤电厂排放烟气的SO2治理已逐步走向正轨,新建的燃煤电厂基本都安装效率较高的脱硫装置.因此,控制NOx的排放将是下一步的主要任务.对选择性催化还原法(SCR)、非选择性催化还原法(SNCR)、电子束或电晕放电脱硝法、光催化氧化法等烟气中NOx控制技术的机理、现状、发展趋势和主要优缺点进行了详尽的论述.通过对各种工艺技术的脱除效率、应用条件、经济性等方面的分析、比较和总结,提出了未来脱硝技术研究工作的重点.基于我国的实际情况提出了烟气脱硝的可行方案,从而为工业废气脱硝技术的进一步开发和研究提供参考.     

炼化企业自备电厂燃煤锅炉烟尘超低排放改造技术

国家要求燃煤电厂锅炉要逐步改造为超低排放,相比新建锅炉或大型电厂锅炉,炼化企业自备电厂锅炉改造难度大。本文通过对炼化企业电厂锅炉现有环保设施和排放现状进行分析,对比了脱硫塔前干式除尘、塔内提级增效、塔后深度除尘等3种工艺技术方案的效果,结合已改造实例指出需关注设备腐蚀、SO3脱除、在线监测等方面问题,并提出深度改造技术方案和实施路线。     

燃煤电厂多污染物控制联合脱汞方法

针对燃煤电厂汞排放特征,结合SO2、NOx控制技术,分析了实现汞联合控制的基理,介绍了近年来国内外烟气多污染物处理技术方面最新的研究进展,主要包括SO2控制设备联合脱汞技术以及SO2、NOx、汞联合脱除技术,并对其技术性能进行了对比.     

预留烟气脱氮空间应注意的问题

重点介绍选择性催化脱氮法(SCR)的工作原理，工艺流程，对SCR所占空间作了初步估算，为电厂预留脱除氮氧化合物装置的空间提供参考，同时对加装SCR装置后应注意的问题提出看法。     

液相催化氧化法脱除燃煤烟气中多污染物研究进展

针对燃煤烟气中SO₂、NO_x和重金属Hg等污染物,可将多个单一污染物控制系统串联进行脱除,但存在系统庞杂、运行成本高等问题,因此开发经济高效的一体化脱除技术十分必要。液相催化氧化法能够在液相中对多污染物进行联合脱除。根据使用氧化剂的不同,对不同的液相催化氧化法进行了详细论述,包括H₂O₂氧化法、次氯酸盐及亚氯酸盐氧化法、过二硫酸盐和过一硫酸氢盐氧化法等,总结了各种方法的优缺点,并对未来的研究方向提出了建议。     

高效脱除SO_2和NO_x的电子束照射法

综述了近年来电子束照射法处理烟气中硫、硝同时脱除技术的发展过程和存在问题;论述了该法脱除SO_2、NO_x的机理和影响因素;经过几种烟气脱硫脱硝方法的经济比较表明,电子束照射法经济上是可行的、技术上是先进的,利用电子束照射法处理烟气是有一定意义的。     

燃煤烟气中CO_2脱除方法的分析与探讨

作为主要的温室气体,CO2减排问题引起全球范围的广泛关注。阐述了燃煤烟气中CO2脱除的多种方法,分析比较了CO2的吸收法、吸附法、膜分离法等的特点及各自的优缺点,侧重介绍了有机胺和氨水脱除的技术进展,并介绍了氨水烟气脱碳的部分试验结果。     

燃煤电厂烟气中汞控制技术研究

介绍了溶解法、吸附法、化学法和鳌合法等4种燃煤电厂烟气脱汞技术。从机理上分析了烟气脱汞技术的工艺过程,对脱汞技术的进一步开发和工业化进程具有促进作用。     

Leaching characteristics of paraffin waste forms generated from Korean nuclear power plants

Leaching tests of paraffin waste forms including boric acid, cobalt, strontium and cesium were performed to investigate the leaching characteristics of paraffin waste forms which had been generated in Korean nuclear power plants. The leaching tests were conducted according to ANSI/ANS-16.1 test procedure and the cumulative fractions leached (CFLs) of boric acid, cobalt, strontium and cesium were obtained. The compressive strength before and after the leaching test was measured for various waste forms with different mixing ratios of boric acid to paraffin. It was observed that boric acid and other nuclides immobilized within paraffin waste forms were congruently released and the leaching rates were influenced by reacted layer depth as the dissolution reaction progressed. A shrinking core model based on the diffusion-controlled dissolution kinetics was developed in order to simulate the test results. The CFLs and the leaching rates were well expressed by the shrinking core model and the cross-sectional view of specimen after the test demonstrated the applicability of this model with the shrinking dissolution front to the leaching analysis of paraffin waste forms.     

脱硝催化剂的失活机理及其再生技术

采用SEM、XRD和XRF对电厂失活脱硝催化剂进行表征,探讨其失活原因和机理。结果表明:电厂脱硝催化剂失活的主要原因是活性组分V的流失及碱金属K、碱土金属Ca和As元素造成的催化剂中毒,烟气中飞灰的沉积也有一定的影响。经吹扫、水洗、酸洗和V负载再生,催化剂的各项物化性质基本恢复,NOx转化率基本达到新鲜催化剂的水平。水洗主要去除催化剂中的碱金属,酸洗主要去除As2O3,负载V补充催化剂活性组分。V再生催化剂在较高温度下的抗硫性能更好。     

Structure and Property of Porous Polyvinylalcohol Hydrogels for Microorganism Immobilization

The porous polyvinylalcohol (PVA) hydrogel was prepared by chemical crosslinking in the saturated boric acid solution with sodium bicarbonate (SBC) as porogen. It was found that addition of SBC decreased the mechanical strength of the gel beads, while the gel permeability was improved. The equilibrium swelling rate and the swelling rate constant k of gel beads increased significantly by addition of SBC. Most of water in PVA hydrogel was in the form of free water and freezing bound water. With increasing SBC content, the total water content of the gel increased, in which the free water content increased remarkably, due to the formation of a large number of pores, and in the meantime, n values, characterizing the mole content of non-freezing bound water, were also improved greatly, indicating of the enhancement of the interaction between PVA molecules and water molecules. SEM observation showed that by adding SBC, many pores formed on the surface and inside gels, which provided channels for microbial metabolites. Microorganism could be successfully entrapped in the porous PVA beads, and addition of SBC made COD removal rate of the gel beads increase significantly.     

高含水油泥调质脱稳用剂

高含水油泥主要来自于页岩气田、油气田和炼厂的污水处理场（站）,含水率一般高达90%以上,成分复杂、乳化严重,是性质稳定的多相体系。破胶脱稳是高含水油泥处理处置与利用的前提,也是减量化的瓶颈,其核心是调质脱稳用剂的优选。介绍了高含水油泥的性质及调质脱稳的原理和方法,阐述了高含水油泥调质脱稳用剂的研究及应用现状,总结了助滤剂、氧化剂、电解质、破乳剂、絮凝剂和微乳化剂等常用药剂的调质机理、适应范围、研究实例和优缺点,并提出了调质脱稳用剂未来的发展方向。     

废弃线路板热解油合成改性酚醛树脂

以废弃线路板热解油为原料，采用碱溶—中和—萃取工艺提取其中以苯酚为主的粗酚，并合成改性酚醛树脂。合成硼酸改性酚醛树脂的优化工艺条件为n(粗酚)∶n(外加苯酚)=2∶3，n(粗酚+外加苯酚)∶n(甲醛)∶n(NaOH)∶n(硼酸)=1∶1.5∶0.15∶0.17;合成有机硅改性酚醛树脂的优化工艺条件为n(粗酚)∶n(外加苯酚)=2∶3，n(粗酚+外加苯酚)∶n(甲醛)∶n(NaOH)∶n(正硅酸乙酯)=1∶1.3∶0.1∶0.1。所合成的硼酸改性和有机硅改性酚醛树脂的主要性能指标均满足YB/T4131—2005《耐火材料用酚醛树脂》中牌号为PFn-5301的热固性液体树脂性能的要求。     

The potential of foliar treatments for enhanced phytoextraction of heavy metals from contaminated soil

Phytoextraction is the plant‐based removal of inorganic contaminants from the soil by root absorption and subsequent translocation to harvestable plant parts. The efficiency of this technique is limited by the phytoavailability of these contaminants in the soil and the root‐to‐shoot transport. To enhance the phytoextraction efficiency, the use of soil amendments has been widely investigated. Potential risks such as increased ecotoxicological effects and leaching of mobilized contaminants caution against the use of persistent mobilizing agents. The potential use of foliar amendments to enhance mineral absorption and/or translocation offers prospects for complementing or substituting soil amendments for enhanced phytoextraction purposes. This study presents an explorative screening to evaluate the feasibility of this approach. Helianthus annuus giganteus plants were grown in moderately contaminated dredged sediment for ten weeks, with daily foliar treatments from week six onward: (1) distilled water (control), (2) magnesium‐ethylenediaminetetraacetic acid (Mg‐EDTA), (3) diethylenetriaminepentaacetic acid (DTPA), (4) nitrilotriacetic acid (NTA), (5) citric acid, (6) oxalic acid, (7) calcium acetate, (8) ammonium thiocyanate (NH₄SCN), and (9) cystein. Applied doses varied between treatments based on plant tolerance: 15 μmol per plant for cystein, 60 μmol per plant for DTPA and NH₄SCN, 180 μmol per plant for Mg‐EDTA and NTA and 400 μmol per plant for the organic acids. At the end of the experiment, shoot accumulation of cadmium, chromium, copper, iron, manganese, nickel, lead, and zinc was evaluated. © 2004 Wiley Periodicals, Inc.     

化工园区生化出水氯代烃污染物的臭氧氧化降解

以化工园区污水处理厂生化出水为背景水样,考察了臭氧氧化对2,4,6-三氯酚、氯苯、1,2-二氯苯、对硝基氯苯、四氯酞酸5种特征氯代烃污染物的降解效果,并对其降解动力学进行了分析。实验结果表明:臭氧对2,4,6-三氯酚和氯苯的降解效果最好,反应30 min时的去除率均接近100%,其次为1,2-二氯苯和对硝基氯苯,反应30 min时的去除率分别为95.7%和36.0%,最差为四氯酞酸,反应30 min时的去除率仅为8.9%;臭氧对2,4,6-三氯酚和对硝基氯苯的降解符合零级动力学方程,对氯苯和1,2-二氯苯的降解符合一级动力学方程,对四氯酞酸的降解符合二级动力学方程。     

交联壳聚糖/沸石复合吸附剂的制备及性能

用沸石负载由缩水甘油基三乙基氯化铵交联的壳聚糖，制得了性能良好的交联壳聚糖/沸石复合吸附剂。研究了该吸附剂应用性能的影响因素，探讨了该吸附剂的吸附性、沉降性和重复使用性，利用FTIR仪和高倍透射电子显微镜对该吸附剂的结构进行了表征。实验结果表明:壳聚糖的交联度为0.93、交联壳聚糖与沸石的质量比为0.045时，制得的交联壳聚糖/沸石复合吸附剂对腐殖酸的去除率可达81.4%，吸附量为4.07mg/g;交联壳聚糖/沸石复合吸附剂对腐殖酸的吸附性能较沸石有显著提高，沉降时间较交联壳聚糖明显缩短;经二次洗脱后腐殖酸去除率仍可达80.2%，腐殖酸吸附量为4.01mg/g。     

Remediation of chlorinated ethenes,ethanes, and methanes in groundwater using carbon‐ and iron‐based electron donor

Field‐scale pilot tests were performed to evaluate enhanced reductive dechlorination (ERD) of dissolved chlorinated solvents at a former manufacturing facility located in western North Carolina (the site). Results of the site assessment indicated the presence of two separate chlorinated solvent–contaminated groundwater plumes, located in the northern and southern portions of the site. The key chlorinated solvents found at the site include 1,1,2,2‐tetrachloroethane, trichloroethene, and chloroform. A special form of EHC^® manufactured by Adventus Americas was used as an electron donor at this site. In this case, EHC is a pH‐buffering electron donor containing controlled release carbon and ZV Iron MicroSphere 200, a micronscale zero‐valent iron (ZVI) manufactured by BASF. Approximately 3,000 pounds of EHC were injected in two Geoprobe^® boreholes in the saprolite zone (southern plume), and 3,500 pounds of EHC were injected at two locations in the partially weathered rock (PWR) zone (northern plume) using hydraulic fracturing techniques. Strong reducing conditions were established immediately after the EHC injection in nearby monitoring wells likely due to the reducing effects of ZV Microsphere 200. After approximately 26 months, the key chlorinated VOCs were reduced over 98 percent in one PWR well. Similarly, the key chlorinated solvent concentrations in the saprolite monitoring wells decreased 86 to 99 percent after initial increases in concentrations of the parent chlorinated solvents. The total organic carbon and metabolic acid concentrations indicated that the electron donor lasted over 26 months after injection in the saprolite aquifer. © 2009 Wiley Periodicals, Inc.     

Optimizing Cr(VI) adsorption on activated carbon produced from heavy oil fly ash

In order to explore the beneficial utilization of heavy oil fly ash (HOFA) generated in the power plants, the present study is intended to optimize the chromium(VI) [Cr(VI)] adsorption on activated carbon produced from HOFA. The raw HOFA obtained from a power plant was washed by nitric/hydrochloric acid and activated at 800 °C with a holding time of 60 min to produce fly ash activated carbon (FAC). Phosphoric acid was used as a chemical agent to improve the surface characteristics of the HOFA during the activation process. Batch adsorption experiments were employed to evaluate the effects of different parameters such as initial Cr(VI) concentration, pH, and FAC dose on the removal of Cr(VI) from aqueous solution. A total of 17 adsorption experimental runs were carried out employing the detailed conditions followed the response surface methodology based on the Box–Behnken design. The results indicate that developed FAC has the potential for removing Cr(VI) from wastewater. Under the test conditions, a maximum of 91.51 % Cr(VI) removal efficiency was achieved.