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采用Ca(ClO)2溶液在高效反应瓶中与模拟烟气进行脱硫脱硝实验,考察了模拟烟气中SO2和NOx的去除效果,以动力学为理论基础研究了Ca(ClO)2的脱硫脱硝性能。实验结果表明:在模拟烟气中SO2,NO,NO2的质量浓度分别为3700,1300,820 mg/m^3及Ca(ClO)2溶液浓度为0.35 mol/L的条件下,SO2去除率达到100%,NOx去除率达到67%。脱硫过程中吸收液中的ClO-是100%脱硫率的保障。Ca^2+吸收SO2的反应速率呈现一级反应的特征。得到的脱硫产物CaSO4·2H2O达到了工业石膏的品质要求。同时脱硫脱硝时NOx和SO2具有协同作用。 相似文献
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《矿山资源开发利用与环境保护》2001,(2):13-15
煤炭燃烧过程中产生大量的SO2,对大气环境造成严重的污染,危害人体健康。烟气脱硫是解决SO2污染的主要方法,于法脱硫具有系统简单、投资省、占地面积小、运行费用低等优点。但目前此方法脱硫效率较低,即使在相当高的钙硫比条件下,吸收剂与SO2的反应也不完全。这主要是由于CaSO4的摩尔容积比Ca(OH)2或CaO的大,随着反应的进行,吸收剂的孔隙被堵塞,这个过程阻碍着内部反应的吸收剂与烟气中的SO2进一步发生反应,这样,脱硫效率不高,吸收剂的利用率也低,限制了此种方法的应用。 相似文献
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太原第一热电厂简易湿法脱硫石膏品质及利用 总被引:3,自引:0,他引:3
通过对简易脱硫石膏理化性质及矿物组成的研究发现,虽然石膏外观差、颗粒细、含尘量及石灰石过剩率高,但所含CaSO3质量分数极小,而CaSO4·2H2O质量分数高于一般天然石膏。用它作水泥缓凝剂、水泥矿化剂和生产半水石膏的试验也充分证明:脱硫石膏可完全替代天然石膏。 相似文献
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在循环流厌氧反应器中研究了无机条件下采用厌氧颗粒污泥启动硫酸盐型厌氧氨氧化(S-ANAMMOX)的反应特性。结果表明:在1~124 d的运行时间内,从第37天开始出现了NH4+-N和SO_4~(2-)的同步去除,生成NO_2~-,NO_3~-,反应最终产物为N2和单质硫,NH4+-N和SO_4~(2-)的最高去除率分别达到92.47%和59.3%;当进水nN∶nS较高时,能显著提高NH4+-N去除率和总氮去除率;SO_4~(2-)与NH4+发生氧化还原反应产生NO2-和NO3-是pH降低的过程;进水nN∶nS、进水平均NH_4~+-N、SO_4~(2-)质量浓度和HRT均对S-ANAMMOX反应的氮硫转化比有一定影响,表明S-ANAMMOX反应是一个多步反应。 相似文献
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赖氨酸废水的处理和氨回收 总被引:2,自引:0,他引:2
对赖氨酸浓废水调 p H沉淀处理后的澄清水进行预处理 :先加入石灰乳 ,搅拌、沉淀 ,SO42 -从 2 0 0 0 0 m g/ L 左右降至 130 0 mg/ L 左右 ,去除率为 94%左右 ,然后进行空气吹脱 ,NH3- N从 5 0 0 0 mg/ L左右降至 80 m g/ L左右 ,去除率 >98%。吹脱出水经厌氧生化处理后 ,再进行空气吹脱 ,NH3- N从 70 0 mg/ L 左右降至 85 mg/ L 左右 ,去除率 >86 %。再吹脱出水与稀废水混合后进行好氧生化和 A/ O、O系统处理 ,出水的 COD<10 0 m g/ L,BOD5<2 0 mg/ L,SS<70 mg/ L,NH3- N<2 5 m g/ L。对浓废水与石灰乳混合后搅拌过程中及两次空气吹脱过程中挥发的 NH3进行回收 ,将其与 H2 SO4反应 ,生成的 (NH4) 2 SO4回用于生产 相似文献
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A series of novel mortars were developed from composite binder of uncalcined FGD gypsum, fly ash (FA) and ground granulated blast furnace slag (GGBFS) for the good utilization of flue gas desulphurization (FGD) gypsum. At a fixed ratio (20%) of GGBFS to the composite binder, keeping consistency of the mortar between 9.5 and 10.0 cm, the properties of the composite mortar were studied. The results show that higher water/binder (W/B) is required to keep the consistency when increasing the percentage of FGD gypsum. No obvious influences of the W/B and content of FGD gypsum on the bleeding of paste were observed which keeps lower than 2% under all experimental conditions tried. The highest compressive and flexural strengths (ratio is 20% FGD gypsum, 20% GGBFS and 60% FA) are 22.6 and 4.3 MPa at 28 days, respectively. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) results indicate that massive ettringite crystals and C-S-H gels exist in the hydration products. At 90 days the mortars with FGD gypsum is dramatically smaller drying shrinkage (563-938 micro strain) than that without FGD gypsum (about 2250 micro strain). The release of the SO(4)(2-) from the mortar was analyzed, indicating that the dissolution of sulfate increases with FGD gypsum. The concentration of SO(4)(2-) releasing from the mortar with 10% FGD gypsum is almost equal to that obtained from the mortar without FGD gypsum. The release of SO(4)(2-) from the mortar with 20% FGD gypsum is 9200 mg·m(-2), which is lower than that from the mortar with 95% cement clinker and 5% FGD gypsum. 相似文献
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Leachate migration from spent mushroom substrate through intact and repacked subsurface soil columns 总被引:2,自引:0,他引:2
Field weathering of spent mushroom substrate (SMS) produces soluble compost leachate that percolates into underlying soils and may adversely impact groundwater. Laboratory experiments were conducted to investigate movement and retention of SMS leachate solutes in subsurface soil columns. Spent mushroom substrate leachate with high concentrations of dissolved organic matter (DOM) and inorganic salts was passively loaded to intact and repacked columns of Bt1 soil (fine-loamy, mixed, semiactive, mesic Typic Hapludults) and effluents were monitored for changes in chemical composition. Transport of SMS leachate in undisturbed soil cores was mainly via preferential flow, whereas matrix flow was predominant in repacked soil columns. Leachate DOM and phosphate were sorbed by soil minerals while Cl-, SO4(2-), Na+ and NH4+ were eluted. Leachate K+ displaced exchangeable native cations and was retained. Biodegradation of leachate DOM resulted in reduction and elution of soil Mn and Fe, especially in repacked columns. Persistent anoxia also inhibited nitrification. Precipitation of gypsum and CaCO3 blocked preferential flow channels, and movement of SMS leachate was subsequently reduced. The results demonstrate that SMS leachate migrates via rapid preferential flow initially, followed by matrix flow at a lower rate. Leachate solutes may transport to depth in soil profiles through preferential channels. To protect water resources, weathering of deep SMS piles should be conducted on compact surfaces or in fields with a condensed soil layer (no structural cracks) above the groundwater table, and measures controlling leachate runoff be imposed. 相似文献
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采用离子交换和加入石灰的方法处理邻氨基苯甲酸生产废液,去除其中的Na^+和SO4^2-,保留其中的NH4^+和邻硝基苯甲酸,处理后的废液回用于生产过程中,不仅消除了废液外排所产生的污染,还回收了NH4^+和ONA,有较好的经济效益。 相似文献
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This research has applied different chemical activators to mechanically and thermally treated fine fraction (<14 mm) of incinerator bottom ash (IBA), in order to investigate the influences of chemical activators on this new pozzolanic material. IBA has been milled and thermally treated at 800 degrees C (TIBA). The TIBA produced was blended with Ca(OH)(2) and evaluated for setting time, reactivity and compressive strength after the addition of 0.0565 mole of Na(2)SO(4), K(2)SO(4), Na(2)CO(3), K(2)CO(3), NaOH, KOH and CaCl(2) into 100g of binder (TIBA+Ca(OH)(2)). The microstructures of activated IBA and hydrated samples have been characterized by X-ray diffraction (XRD) and thermogravimetry (TG) analysis. Thermal treatment is found to produce gehlenite (Ca(2)Al(2)SiO(7)), wollastonite (CaSiO(3)) and mayenite (Ca(12)Al(14)O(33)) phases. The thermally treated IBA samples are significantly more reactive than the milled IBA. The addition of Na(2)CO(3) can increase the compressive strength and calcium hydroxide consumption at 28-day curing ages. However, the addition of Na(2)SO(4), K(2)SO(4), K(2)CO(3), NaOH and KOH reduces the strength and hydration reaction. Moreover, these chemicals produce more porous samples due to increased generation of hydrogen gas. The addition of CaCl(2) has a negative effect on the hydration of TIBA samples. Calcium aluminium oxide carbonate sulphide hydrate (Ca(4)Al(2)O(6)(CO(3))(0.67)(SO(3))(0.33)(H(2)O)(11)) is the main hydration product in the samples with activated IBA, except for the sample containing CaCl(2). 相似文献
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冷冻固定化硝化菌去除废水中氨氮的研究 总被引:4,自引:0,他引:4
采用聚乙烯醇(PVA)循环冷冻法制备固定化硝化菌颗粒,经活化后在颗粒填充率为9%的三相流化床中进行氨氮废水处理试验。处理低浓度氨氮有机废水(NH3-N质量浓度为75mg/L.COD约为400mg/L,水力停留时间为4h)时,NH3-N去除率约为90%,COD、TIN的去除率可达82%和60%左右;处理高浓度氨氮废水(NH3-N质量浓度450~500mg/L,水力停留时间为20h)时,NH3-N去除率在98%以上,氨氧化产物中NO2^--N质量分数在95%以上,为亚硝酸盐反硝化提供了有利条件。用该法制成的硝化菌颗粒寿命在3个月以上。 相似文献
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火电厂烟气脱硝装置中的二氧化硫、灰分、氨及催化剂中的各种重金属在高温烟气的作用下发生各种化学作用,生成的硫酸氢氨等产物对火电厂的各种设备均会产生不同影响.同时由于系统阻力及荷载的变化,也会对电厂其他相关设备产生影响,根据目前工程的运行经验,火电厂在增设脱硝装置后,均会对空气预热器、引风机、锅炉钢架等进行改造.通过综合分析烟气脱硝装置产生的影响原因及解决办法,为脱硝装置的设计提供参考. 相似文献
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Eusden JD Gallagher L Eighmy TT Crannell BS Krzanowski JR Butler LG Cartledge FK Emery EF Shaw EL Francis CA 《Waste management (New York, N.Y.)》2002,22(2):117-135
The use of soluble PO4(3-) and lime as a heavy metal chemical stabilization agent was evaluated for mine tailings from Leadville, Colorado. The tailings are from piles associated with the Wolftone and Maid of Erin mines; ore material that was originally mined around 1900, reprocessed in the 1940s, and now requires stabilization. The dominant minerals in the tailings are galena (PbS), cerrusite (PbCO3), pyromorphite (Pb5(PO4)3Cl), plumbojarosite (Pb0.5Fe3(SO4)2(OH)6), and chalcophanites ((Pb,Fe,Zn,Mn)Mn2O5 x 2H2O). The tailings were treated with soluble PO4(3-) and lime to convert soluble heavy metals (principally Pb, Zn, Cu, Cd) into insoluble metal phosphate precipitates. The treatment process caused bulk mineralogical transformations as well as the formation of a reaction rind around the particles dominated by Ca and P. Within the mineral grains, Fe-Pb phosphosulfates, Fe-Pb sulfates (plumbojarosite), and galena convert to Fe-Ca-Pb hydroxides. The Mn-Pb hydroxides and Mn-(+/-Fe)-Pb hydroxides (chalcophanites) undergo chemical alteration throughout the grains during treatment. Bulk and surface spectroscopies showed that the insoluble reaction products in the rind are tertiary metal phosphate (e.g. (Cu,Ca2)(PO4)2) and apatite (e.g. Pb5(PO4)3Cl) family minerals. pH-dependent leaching (pH 4,6,8) showed that the treatment was able to reduce equilibrium concentrations by factors of 3 to 150 for many metals; particularly Pb2+, Zn2+, Cd2+, and Cu2+. Geochemical thermodynamic equilibrium modeling showed that apatite family and tertiary metal phosphate phases act as controlling solids for the equilibrium concentrations of Ca2+, PO4(3-) Pb2+, Zn2+, Cd2+, and Cu2+ in the leachates during pH-dependent leaching. Both end members and ideal solid solutions were seen to be controlling solids. 相似文献