Oxidation of sulphite originating from flue gas desulphurization waste in soil

The rate of catalyzed oxidation of sulphite originating from flue gas desulphurization (FGD) waste was studied under varying conditions. The pH dependence was examined in aqueous solution at the pH range of 5 to 8, the effect of soil moisture was studied in sieved soil of different moisture contents, and the oxidation of sulphite to a soil as FGD waste, was measured at different depths in a field experiment. The experiments that the half-lives of sulphite in aqueous solution were between 0.5 and 2 hours and that the oxidation rate was highest at the lowest pH. In sieved soil the half-lives of sulphite were in the range of 3 to 20 days with the oxidation rate at the highest moisture content, indication that oxygen availability was the limiting factor. The slowest decrease of the sulphite concentration was found at a soil depth of 8–10 cm which was the where the highest background concentration of sulphite was found in control plots, too.Environmental Geochemistry and Health, 1988,10(1), 26–30     

Inorganic element uptake by barley from soil supplemented with flue gas desulphurization waste and fly ash

To evaluate the influence of waste products from coal- and oil-fired power plants on the inorganic element content of plants, barley was grown in pots each with 22 kg of sandy loam supplied with increasing amounts of six waste products. The plants were harvested at maturity and analysed for a number of inorganic elements. The salinity of the soil was the limiting factor for the amount added in terms of plant growth. Concerning the quality of the plants as fodder, addition of the waste to the soil at levels of about 0.5% by weight increased the Se concentration of the barley from a level deficient for animals to that approaching sufficiency for animals. The increase in Cd from the flue gas desulphurization (FGD) products was deemed undesirable, even though the concentrations following this single addition were far from toxic. All other increases in element concentrations were without any biological significance.Environmental Geochemistry and Health, 1988,10(1), 21–25     

Ispra Mark 13A,a new process for flue gas desulphurization

A new regenerative wet scrubbing process for flue gas desulphurization, Ispra Mark 13A, is presented. The process produces two useful products, concentrated sulphuric acid and hydrogen. Process flow schemes and process principles are discussed.     

The disposal of flue gas desulphurisation waste: sulphur gas emissions and their control

Flue gas desulphurisation (FGD) equipment to be fitted to UK coal-fired power stations will produce more than 0.8 Mtonnes of calcium sulphate, as gypsum. Most gypsum should be of commercial quality, but any low grade material disposed as waste has the potential to generate a range of sulphur gases, including H₂S, COS, CS₂, DMS and DMDS. Literature data from the USA indicates that well-oxidised waste with a high proportion of calcium sulphate (the main UK product of FGD) has relatively low emissions of sulphur gases, which are comparable to background levels from inland soils. However, sulphur gas fluxes are greatly enhanced where reducing conditions become established within the waste, hence disposal strategies should be formulated to prevent the sub-surface consumption of oxygen.     

Heavy metals in flue gas cleaning residue

During combustion, most of the inorganic nutrients and trace elements in the fuel are retained and enriched in the ash. However, here we show that, due to the low total heavy metal concentrations, the flue gas cleaning residue (i.e. the fly ash) originating from the wet scrubber device at a medium-sized (32 MW) municipal district heating plant, is a potential forest fertilizer. Furthermore, the easily soluble calcium (1,980 mg kg⁻¹; d.w.) and phosphorus (50 mg kg⁻¹; d.w.) concentrations indicate that the flue gas cleaning residue is a potential agent for soil remediation and for improving soil fertility.     

Hazardous waste solidification as a multiple barrier concept

The GFS process of waste solidification using pozzolanic material is described. This process is most successful for hazardous particulates. Final products have better landfilling properties in terms of fixing the hazardous contents of wastes, reducing leachates and improving the geo‐physical strength of particulates than the starting waste materials. Furthermore, recycling of metals from sludges of industrial processes as well as of biomass from municipal sewage sludges for agricultural purposes are improved.     

水稻小麦种植模式下长期定位施肥土壤氮的垂直变化及氮储量

为了研究不同的施肥方式对土壤全氮变化及氮储量的影响,1981年在湖北省农业科学院南湖试验站设置了施用有机肥与化肥的长期定位田间试验,2006年水稻收获后田间取样分析每个处理不同土层的全氮含量与氮储量。研究结果表明：与对照相比,单施化肥与单施有机肥0～20cm土层土壤的容重下降,化肥添加有机肥比相应的单施化肥的容重要低一些。除了对照之外,其它处理都是0～20cm土层土壤全氮含量高于其它土层,氮肥配施有机肥处理0～20cm土层土壤全氮含量最高。除了氮磷钾肥配施过量有机肥处理外,化肥配施有机肥处理土壤的全氮含量都高于单施化肥或单施有机肥处理,20～40cm土层土壤全氮含量具有相似的规律。在0～20cm土层,与对照相比,单施氮肥及氮磷肥不能增加土壤全氮储量,但是化肥配施有机肥能够增加土壤全氮的储量。单施氮磷钾肥及单施有机肥也能够增加土壤全氮的储量。在0～20cm土层,氮肥配施有机肥处理的土壤全氮储量最多,达8.82t·hm-2,而氮肥处理的氮储量最低,仅为5.38t·hm-2。在100cm深度,与单施化肥及单施有机肥相比,化肥配施有机肥都增加了土壤全氮的储量。     

稻季田面水不同形态氮素变化及氮肥减量研究

通过氮肥减量田间小区试验,研究了稻季3次施肥后田面水不同形态氮素的变化特征、水稻产量与氮肥农学效率和环境效应的关系。结果表明：施氮显著增加了田面水的氮素质量浓度,且氮素质量浓度随施氮量的减少而降低。田面水总氮,有机氮在施氮后1 d达到最大,随后快速下降;铵态氮和无机氮在基肥和分蘖肥施用1 d后也达到最大,而在穗肥施用后经历了一个先升后降的变化过程;无机氮是田面水氮素的主要形态,应将无机氮作为农田排水污染检测的主要指标;施氮后1周是防止稻田田面水氮素大量流失的关键时期;随着施氮量的增加,氮肥农学效率不断下降,氮素径流损失不断增大,综合水稻产量、农学效率和环境效应,试验区氮肥减量50%是可行的,但其产量持续性仍需进一步验证。     

Silicon carbide waste as a source of mixture materials for cement mortar

This paper presents an investigation of the feasibility of recycling silicon carbide waste (SCW) as a source of mixture materials in the production of cement mortar. Mortars with SCW were prepared by replacing different amounts of cement with SCW, and the properties of the resulting mortars, such as the fluidity, strength and shrinkage, were studied in this work. Thermogravimetry-differential scanning calorimetry and scanning electron microscopy were employed to understand the reasons for the property changes of the mortars. The results indicate that SCW decreases the initial and 1-h fluidity of fresh mortar but improves the loss of fluidity. The mortar with SCWexhibits a lower strength at 3 d and 7 d but a higher strength at 28 d and 56 d compared to the control. The shrinkage rate of cement mortar with SCW shows an obvious decrease as the replacement ratio increases. In addition, the content of calcium hydroxide in hardened paste also shows that SCW has some impact on the hydration of the cement-SCW system. The microstructures of the hardened paste also show evidence for a later strength change of mortar containing SCW. This work provides a strategic reference for possibly applying SCW as a mixture material in the production of cement mortar.

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气相色谱法测定工业废水中联苯与菲

文章研究了一种新的测定废水中联苯及菲含量的方法,该方法采用气相色谱薄涂柱,对联苯与菲进行了有效的分离与测定。该方法具有固定液用量少,柱温低,分离效果好,分析速度快等特点,利用该对废水样进行了测定,取得了满意的结果。     

Effect of flue gas recirculation on nitric oxide (NO) emissions during the coal grate-fired process

Flue gas recirculation (FGR) is a low nitrogen oxide (NO_X) combustion technology. The present study used standard gas to simulate the cycle gas (the main ingredients of which are oxygen (O₂), nitrogen (N₂), and carbon dioxide (CO₂)). The coal grate-fired process was divided into three zones, namely (1) volatilization zone, (2) main combustion zone, and (3) char combustion and burn-out zone. The effects of FGR on coal combustion and NO emissions were investigated in these zones of a unit-boiler experimental system. An industrial test was then conducted on a chain boiler that previously used FGR. Data showed that if the cycle gas was directed into the furnace from the volatilization zone, the curve of the coal surface temperature moved backwards, the temperature peak increased, and coal ignition was delayed. When the FGR rate was 20%, NO emissions/g coal was 41.8% less than in the absence of FGR, in the overall combustion process except for the volatilization zone. An industrial test demonstrated that FGR decreased the NO emissions and incomplete-combustion loss of gas. NO and carbon monoxide (CO) emissions were reduced by 26.9 and 38%, respectively. These observations may prove to be beneficial in reducing ambient air pollution and saving energy.     

氮肥运筹和少免耕对麦田氮素径流流失的影响

采用田间小区定位试验研究了自然降雨条件下氮肥运筹和少免耕措施对稻麦两熟农田麦季氮素径流流失特征的影响。结果表明：自然降雨后麦田耕层土壤平均水分质量分数26.34%为径流事件发生的临界土壤水分质量分数。常规施肥（T0）条件下,麦季径流水量达2185.05 m3·hm-2,径流侵蚀泥沙量达716.08 kg.hm-2,少免耕（T2）处理增加麦田径流水量达29.67%,减少径流侵蚀泥沙量达13.96%,而肥料运筹（T1）与T0处理差异不显著;就整个麦季而言,T0处理条件下,径流水全氮（TN）平均质量浓度和径流侵蚀泥沙TN平均质量分数分别为10.51 mg·L-1和1.19 g·kg-1,T1处理显著降低径流水TN质量浓度和侵蚀泥沙TN质量分数分别达11.63%和5.93%,T2处理显著降低径流侵蚀泥沙TN质量分数达7.95%;麦季氮素径流流失主要集中在小麦生育前期,包括径流水氮素流失量和径流侵蚀过程中由泥沙流失的氮素量。T0处理条件下,氮素流失总量达31.76 kg·hm-2,其中,径流水氮素流失量占麦季氮素总流失量95%以上,T1处理减少麦季氮素总流失量达9.25%,而T2处理则增加麦季氮素总流失量达16.75%。     

A regional market for rights to use fertilizer as a means of achieving water quality standards

The attributes and effects of one possible arrangement of a market for rights to use fertilizer are discussed in this article. Because of some similarities in effect, this type of policy is compared with the imposition of a fixed per unit excise tax on fertilizer. Some empirical results for the establishment of a market for rights to use nitrogen fertilizer and for the imposition of a tax on nitrogen fertilizer only in Illinois are presented. These results are derived from a national spatial equilibrium model of crop production in the United States.     

Calcium carbonate waste from an integrated pulp and paper mill as a potential liming agent

Calcium carbonate is used in large amounts in the pulp and paper industry as a paper filler. When it is manufactured, the calcium carbonate waste is purged from the process. Here we demonstrate that, due to the elevated calcium concentration of 168.5 g kg⁻¹ dry weight (dw), alkaline pH of 12.6 and neutralizing (liming) effect value of 42.4% expressed as Ca equivalents, this waste is a potential liming agent and a pH buffer. The heavy metal concentrations in the waste were lower than the new Finnish limit values for fertilizers used in agriculture, as well as for a material, e.g. ash, used as an earth construction agent. These limit values came into force in March 2007 and in June 2006, respectively.     

氮肥种类及用量对赤红壤pH和可溶性盐的影响

为了探讨施用氮肥对赤红壤性土壤pH和可溶性盐的影响,以赤红壤上发育的水稻土为供试土壤,以油麦菜(Lactucasativa L)为栽培作物,采用盆栽试验,研究了在施等量的磷(P2O5 0.08 g·kg-1)、钾(K2O 0.16 g·kg-1)条件下,尿素、硫酸铵、氯化铵、硝酸铵4个氮肥品利吸其不同用量水平(0、0.08、0.16、0.24和0.32 g·kg-1)下土壤的pH和可溶性盐的变化情况.结果表明,施用氮肥的利,类及用量对赤红壤性土壤的pH、可溶性盐及K 、Na 、Ca2 和Mg2 的质量分数有显著影响;随着氮肥用量的增加,土壤pH显著降低,而可溶性盐及K 、Na .、Ca2 和Mg2 的质量分数则升高;在各施氮水平下,(NH4)2SO4、NH4Cl对土壤pH、可溶性盐及K 、Na 、Ca2 和Mg2 的质量分数的影响总体上明显大于CO(NH2)2、NH4NO3.     

烟气脱硫菌株的筛选与烟气脱硫效率的影响因素

为了寻找烟道气中SO2的微生物转化方法,为微生物脱硫技术的工业化应用提供一定的技术依据,进行了烟气脱硫菌株的筛选和影响烟气脱硫效率有关因素的实验研究,结果表明,单一菌株中,5-2-1菌株的脱硫效率最高.培养12 d后,脱硫率达67.20%,与单一菌株相比,混合菌株有更好的脱硫能力;重金属、有机物、氟化物质对菌株脱硫能力的影响结果表明,在菌液中添加Fe3 、Mn2 不仅能促进菌株生长,还能提高生物菌株的脱硫能力;通过正交实验得出,影响生物菌株脱硫能力大小的因素顺序为:Fe3 >Mn2 >联苯>SO2 浓度>Cr3 >pb2 >pH,通过F显著性检验得知,Fe3 、Mn2、联苯的作用是显著的.     

Biogeochemistry of a temperate forest nitrogen gradient

Wide natural gradients of soil nitrogen (N) can be used to examine fundamental relationships between plant-soil-microbial N cycling and hydrologic N loss, and to test N-saturation theory as a general framework for understanding ecosystem N dynamics. We characterized plant production, N uptake and return in litterfall, soil gross and net N mineralization rates, and hydrologic N losses of nine Douglas-fir (Pseudotsuga menziesii) forests across a wide soil N gradient in the Oregon Coast Range (U.S.A.). Surface mineral soil N (0-10 cm) ranged nearly three-fold from 0.29% to 0.78% N, and in contrast to predictions of N-saturation theory, was linearly related to 10-fold variation in net N mineralization, from 8 to 82 kg N.ha(-1) x yr(-1). Net N mineralization was unrelated to soil C:N, soil texture, precipitation, and temperature differences among sites. Net nitrification was negatively related to soil pH, and accounted for <20% of net N mineralization at low-N sites, increasing to 85-100% of net N mineralization at intermediate- and high-N sites. The ratio of net: gross N mineralization and nitrification increased along the gradient, indicating progressive saturation of microbial N demands at high soil N. Aboveground N uptake by plants increased asymptotically with net N mineralization to a peak of approximately 35 kg N.ha(-1) x yr(-1). Aboveground net primary production per unit net N mineralization varied inversely with soil N, suggesting progressive saturation of plant N demands at high soil N. Hydrologic N losses were dominated by dissolved organic N at low-N sites, with increased nitrate loss causing a shift to dominance by nitrate at high-N sites, particularly where net nitrification exceeded plant N demands. With the exception of N mineralization patterns, our results broadly support the application of the N-saturation model developed from studies of anthropogenic N deposition to understand N cycling and saturation of plant and microbial sinks along natural soil N gradients. This convergence of behavior in unpolluted and polluted forest N cycles suggests that where future reductions in deposition to polluted sites do occur, symptoms of N saturation are most likely to persist where soil N content remains elevated.     

Trace analysis of airborne toluene diisocyanate as a pentafluorobenzyl derivative by gas chromatography with electron capture detection

Trace analysis of airborne toluene diisocyanate (TDI) vapor was accomplished by measuring the derivative using gas chromatography with electron‐capture detector after collecting gas samples with a microimpinger containing 2 ml toluene, 1 μl pentafluorobenzyl alcohol, and 1 μl triethylamine. The sampling efficiency was determined to be 99.4% for short‐term exposure level of TDI and the 2,4‐ and 2,6‐isomers of TDI were well separated. The derivative was identified to be a new compound with a molecular weight of 570 by mass spectrometry in fast atomic bombardment mode and nuclear magnetic resonance spectrometry. This method is convenient and can be applied in the field where airborne TDI is in vapor form.     

生物滴滤塔耦合光催化氧化技术处理电子垃圾拆解车间排放废气的中试研究

采用生物滴滤塔（BTF）与光催化一体化（PCO）联用工艺应用于电子垃圾拆解现场废气处理的中试研究,研究结果表明：电子垃圾拆解现场排放的废气中含有高浓度的总悬浮颗粒物（TSP）和挥发性有机污染物（VOCs）。其中TSP的质量浓度为3792.5~7387.9μg·m-3,远高于中国环境空气质量控制标准（GB3095—2012）的二级标准（300μg·m-3）;VOCs主要由芳香烃类VOCs、含氮含氧类VOCs、卤代烃类VOCs和脂肪烃类VOCs组成,总VOCs的质量浓度为（5 499.1±854.7）~（26 834.0±447.0）μg·m-3,其中芳香烃类VOCs含量最高,其质量浓度为（2369.9±359.8）~（24419.6±229.5）μg·m-3,其次是含氮含氧类VOCs和卤代烃类VOCs,分别为（1018.2±142.1）~（2144.2±167.5）和（1170.6±146.5）~（1 936.6±353.3）μg·m-3,脂肪烃类VOCs的质量浓度最低,只有（44.6±0.8）~（174.4±0.5）μg·m-3。相较单一BTF和PCO工艺,BTF-PCO联用工艺可以更为有效地去除电子垃圾拆解现场排放废气中的TSP和VOCs。研究结果表明,经过BTF-PCO处理后,出口TSP的质量浓度降低到747.4~1750.9μg·m-3,其去除率在76.3%以上,而对于VOCs来说,出口浓度下降更为明显,芳香烃类VOCs、含氮含氧类VOCs、卤代烃类VOCs和脂肪烃类VOCs的去除率分别大于或者等于97.0%、92.4%、83.4%和100%。