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1.
IntroductionFurfuralisakindofimportantrawmaterialinchemicalindustry.Withthegrowthofitsuse,itsproductionisincreasingannually.Bu?..  相似文献   

2.
采用顶空气相色谱质谱法,利用PEG20M柱测定糠醛废水中的糠醛含量。方法相对标准偏差RSD〈3.7%,相关性r〉0.9999,基体样品回收率为96.5%-102%,检出限0.001mg/L。  相似文献   

3.
Stored solid manure heaps can be a significant source of nitrous oxide (N2O) and methane (CH4) emissions. The manure characteristics influence emissions and solid manure heaps can be managed to promote aerobic decomposition during storage. Increasing the carbon (C) content of the manure heap with high-C additives, such as straw, may provide the opportunity for N2O and CH4 emission reduction. Greenhouse gas (GHG) emissions from conventionally produced farmyard manure (FYM) have been quantified, but there is little data on emissions from organically produced FYM. N2O and CH4 emissions were measured using a small-scale storage method from FYM collected from organic and conventional dairy units under a range of storage conditions with and without extra straw addition.The organic and the conventional FYM were similar in composition except for the higher C and dry matter content in the organic FYM and in the FYM with added straw. This resulted in mean total emissions of N2O and CH4 being lower from the organic (27 g N t−1) than the conventional FYM (52 g N t−1) and from the treatments with straw added (32 g N t−1) than those without (47 g N t−1). The initial C:N ratio and dry matter content of the stored FYM were the most important factors affecting N2O and CH4 emissions although the FYM temperature also affected CH4 emissions. Adding high-C additives, such as straw could be a promising strategy for reducing GHG emissions because it influences the dry matter content, C:N ratio and aeration of the manure. The small-scale FYM storage method were shown to be a reliable and an easy method to quantify emissions under a range of environmental conditions and manure manipulations and so develop effective manure management practices to reduce GHG emissions.  相似文献   

4.
 采用复合添加剂(I),以稻草(或麦杆)为原料,用硫酸酸化水解制糠醛,研究了复合添加剂(I)各成分的含量和添加量以及蒸馏条件对渣酸度的影响.结果表明,以20%(wt/wt,%)硫酸,液固比为3∶1~4∶1(wt/wt),复合添加h们)与原料的比为02:1〔WVWt),添加剂(I)配方为:磷酸钙7%,磷酸和重钙5%-10%,亚硫酸氢钠和碳酸钙3%-5%,助剂(III)5%-10%;蒸馏温度110~130℃,时间2.5~3.0h,出醛率可达理论量的80%以上,废渣全部转化为中性复合肥.  相似文献   

5.
通过大田试验,采用人工增强紫外辐射的方法模拟UV-B增强,应用静态箱-气相色谱法测定土壤-冬小麦系统的CO2排放通量,研究UV-B增强与秸秆施用对土壤-冬小麦系统CO2排放通量的影响.结果表明:UV-B增强与秸秆施用没有改变CO2排放通量的季节性变化规律.UV-B具有抑制效应,显著降低了拔节-孕穗期的CO2排放,降幅达15.48% (P=0.055).秸秆施用对CO2排放具有促进效应,使返青期和拔节 -孕穗期的CO2排放分别增加了59.52% (P=0.005)和13.10% (P=0.092).秸秆施用和UV-B增强处理增加了返青期的CO2排放,增幅为30.95% (P=0.083).对照、UV-B增强、秸秆施用和秸秆施用+UV-B增强4种处理的系统CO2排放与气温都存在极显著的指数关系 (P<0.01),拟合方程的决定系数R2分别为0.56,0.60,0.45和0.51,温度敏感系数Q10值分别为1.83,1.97,1.55和1.70.  相似文献   

6.
采用人工模拟UV-B增强方式,通过大田试验,研究了UV-B增强与秸秆施用对土壤-大豆系统呼吸速率和N2O排放通量的影响.结果表明:在三叶-分枝期、开花-结荚期、鼓粒成熟期和全生长期,UV-B增强,系统平均呼吸速率分别降低了59.88%,65.47%,67.35%和64.44%,N2O平均排放通量分别降低了37.94%,24.61%,48.42%和34.16%;秸秆施用促进了系统呼吸速率,4个时期平均呼吸速率分别增加了59.88%,61.50%,99.16%和64.44%;降低了全生长期的N2O平均排放通量,但没有达到显著差异水平(P=0.236).UV-B增强和秸秆施用复合处理显著增大土壤-大豆系统的呼吸速率,降低全生长期的N2O平均排放通量,但没有达到显著差异水平(P=0.229).  相似文献   

7.
曹威  党志 《环境科学学报》2013,33(9):2466-2472
采用NaOH、环氧氯丙烷和三甲胺改性稻草秸秆,制备出含季铵基的吸附剂,用以去除水中的硫酸根离子(SO2-4).通过SEM、元素分析、13C-NMR表征发现,稻草改性后表面纤维结构暴露,含氮量增加,引入了大量的季铵基,吸附潜力显著提高.吸附实验结果表明,改性稻草吸附去除SO42-平衡时间约20min,pH为3~8范围内吸附效果较好.采用Langmuir吸附模型可较好地描述改性稻草对SO2-4的吸附等温线,其最大单分子层吸附量Qmax为74.76mg·g-1,吸附能力远大于原稻草(11.68mg·g-1).  相似文献   

8.
改性玉米秸秆对水溶液中硝酸根的吸附动力学研究   总被引:2,自引:0,他引:2  
为了将玉米秸秆资源化,成为一种能够有效去除水及废水中硝酸根的吸附剂,将玉米秸秆进行化学改性制备了阴离子交换剂.重点研究了改性玉米秸秆对硝酸根的吸附热力学及动力学特性.结果表明,改性玉米秸秆对硝酸根的吸附均符合Langmuir等温模式和Freundlich等温模式.在20℃和40℃条件下的最大吸附量分别为80.8407 mg·g-1和72.7273 mg·g-1.吸附过程放热,降低温度有利于吸附的进行.改性玉米秸秆对硝酸根的吸附为快速吸附过程,30min内即可达到吸附平衡.改性玉米秸秆对不同初始浓度硝酸根的吸附过程均为一级反应,吸附过程受液膜扩散和颗粒内扩散同时控制.研究结果表明,改性玉米秸秆是一种良好的硝酸根吸附剂.  相似文献   

9.
颗粒粒径对玉米秸秆生物碳吸附锶的影响   总被引:1,自引:0,他引:1  
以玉米秸秆为原材料,采用限氧裂解法于350℃下制备了不同粒径的生物碳(BC-9.31、BC-20.26、BC-60.77、BC-71.07、BC-101.9,数字代表样品的中值径μm),研究颗粒粒径对生物碳吸附锶的影响.结果表明:生物碳的颗粒粒径对核素锶的吸附速率和吸附容量均有显著影响.生物碳对锶的吸附动力学符合准二级动力学模型(R2,0.99),颗粒最细的BC-9.31吸附速率最大(4.48 mg·g~(-1)·h~(-1)).随着颗粒粒径的增加,锶的吸附速率呈指数降低,其吸附速率差异高达20倍.生物碳对锶的吸附等温曲线符合准Langmuir模型(R2,0.94~0.99),饱和吸附容量为9.09~23.81 mg·g~(-1).随着粒径的增大,锶的吸附容量先降低后增高又降低,粒径最小的BC-9.31(23.81 mg·g~(-1))吸附容量最大,吸附容量最小的则是BC-60.77(9.09 mg·g~(-1)),两者相差2.6倍.pH对生物碳吸附锶具有重要影响.在溶液pH值较低时(1.93~4.74),对锶的吸附去除率急剧增加(3.94~9.17倍);而pH值较高时(4.74~11.85),吸附去除率缓慢提高(1.11~1.68倍).pH值也是颗粒粒径影响的重要参数,随pH值增加颗粒粒径对生物碳吸附锶的影响程度显著减小.生物碳极性指数与锶饱和吸附量和吸附速率均呈正相关关系,表明极性官能团是锶的重要吸附位点.  相似文献   

10.
复合催化电解法处理染料工业废水   总被引:21,自引:0,他引:21  
采用复合催化电解法对染料工业废水的处理进行了研究,并获得相应的工艺参数。试验结果表明,复合催化电解法能有效地处理染料工业废水,在电解电压10V、电流0.1A、电解时间1.5h的条件下,催化电解能使废水CODCr去除率达到87.5%~90%,脱色率达99%~100%。复合催化电解法具有操作简便、能耗较低等特点,是处理染料工业废水的一条新途径  相似文献   

11.
Effects of antibiotic residues on methane production in anaerobic digestion are commonly studied using the following two antibiotic addition methods:(1) adding manure from animals that consume a diet containing antibiotics, and(2) adding antibiotic-free animal manure spiked with antibiotics. This study used chlortetracycline(CTC) as a model antibiotic to examine the effects of the antibiotic addition method on methane production in anaerobic digestion under two different swine wastewater concentrations(0.55 and 0.22 mg CTC/g dry manure). The results showed that CTC degradation rate in which manure was directly added at 0.55 mg CTC/g(HSPIKE treatment) was lower than the control values and the rest of the treatment groups. Methane production from the HSPIKEtreatment was reduced(p 〈 0.05) by 12% during the whole experimental period and 15% during the first 7 days. The treatments had no significant effect on the pH and chemical oxygen demand value of the digesters, and the total nitrogen of the0.55 mg CTC/kg manure collected from mediated swine was significantly higher than the other values. Therefore, different methane production under different antibiotic addition methods might be explained by the microbial activity and the concentrations of antibiotic intermediate products and metabolites. Because the primary entry route of veterinary antibiotics into an anaerobic digester is by contaminated animal manure, the most appropriate method for studying antibiotic residue effects on methane production may be using manure from animals that are given a particular antibiotic, rather than adding the antibiotic directly to the anaerobic digester.  相似文献   

12.
复合裂解高效提取菜油脚—皂脚脂肪酸   总被引:1,自引:0,他引:1  
为了解决高效提取菜油脚—皂脚脂肪酸的技术关键,显著提高菜油脚—皂脚脂基裂解率和脂肪酸得率,提出水解― 醇解、皂化复合裂解清洁工艺.结果表明,脂基裂解率98% ,脂肪酸得率96 % ,芥酸纯度95 % .最佳工艺条件及其影响显著性程度为:水与菜油脚—皂脚体积比3:1( 影响显著) ,水解时间12h( 影响显著) ,水解温度190℃,黑脚醇解- 皂化时间8h.  相似文献   

13.
以内蒙古锡林河流域羊草草原典型植被羊草(Leymus chinensis)为研究对象,探讨了4个不同氮素输入水平(0、5、10和20g·m-·2a-1)下羊草叶片功能特性与光合特征的响应,并分析了外源氮输入背景下草地生态系统固碳潜势的变化.结果表明:中等水平施氮(10g·m-·2a-1)显著增加了羊草叶面积、叶绿素相对含量、叶氮浓度与净光合速率,但与中氮相比,高氮(20g·m-·2a-1)输入下却有所下降;施氮不仅对叶片净光合速率有一定程度的促进作用,而且延长了光合作用高峰期的持续时间;随着氮素添加梯度的增加,羊草叶片蒸腾速率降低,瞬时水分利用效率增高,气孔导度增大,胞间CO2浓度逐渐减小.从光合固碳的角度来看,适量的外源氮素输入有利于草地生态系统固定更多的CO2.  相似文献   

14.
露天生物质燃烧是温室气体(CO2、CH4、N2O)的重要排放源之一,这些排放可影响本地、区域和全球的大气化学和气候变化,并带来一系列生态环境问题,进而对人类及其他生物的生存环境产生影响.本研究采用卫星火点排放清单(FINN),对2010—2019年中国露天生物质燃烧温室气体排放进行研究,并分析秸秆禁燃政策对温室气体排放的影响,对后续秸秆禁燃政策的制定具有重要参考价值.结果表明,我国2010—2019年平均年温室气体排放量为1.53×108t(将CH4和N2O的温室效应换算为同等效应的CO2当量单位),总体呈波动性下降趋势.温室气体排放量最大的植被类型是森林(7.43×107t)和农作物(3.19×107t),分别占总排放量的48.7%和20.9%.从月分布来看,露天生物质燃烧排放的温室气体集中在2—6月,3月是高峰值.从空间分布上看,排放主要集中在华南、西南和华东地区,占总排放量的72.9%...  相似文献   

15.

为提升稻田周边湿地对农田径流中不同形态氮的净化效率,有效拦截农田面源污染导致的氮磷流失,采用农业废物稻秸秆为有机碳源与沉水植物组合构建强化湿地系统,共设置不种植苦草且不添加稻秸秆(NS)、只种植苦草(VN)、只添加稻秸秆(SS)和种植苦草并添加稻秸秆(VS)4个处理,研究强化湿地对不同形态氮农田径流的净化效果与机制。结果表明:1)在处理以氨氮(NH4 +-N)为主要氮形态的农田径流时,VN和VS对废水中TN和NH4 +-N的去除率显著高于其他处理(P<0.05),表明种植苦草是提升湿地对NH4 +-N农田径流净化效果的主要因素;2)处理以硝态氮(NO3 -N)为主要氮形态的农田径流时,SS和VS对废水中TN和NO3 -N的去除率显著高于其他处理(P<0.05),表明添加稻秸秆显著提升了湿地对NO3 -N农田径流的净化效果。3)湿地中只种植苦草时对NO3 -N去除效果不佳,只添加稻秸秆时对NH4 +-N去除效果较差,种植苦草并添加稻秸秆对2种形态氮均有较好的去除效果,同时二者对磷的去除效果与只种植苦草的湿地无显著差异。因此,稻秸秆添加强化沉水植物湿地在拦截净化农田面源污染中具有推广应用的潜力。

  相似文献   

16.
Removal of Cr from tannery sludge by bioleaching method   总被引:3,自引:0,他引:3  
Bioleaching of Cr(Ⅲ) from tannery sludge using the mixture of ingenuous iron- and sulfur-oxidizing bacteria was investigated in batch flasks. Experiments involved the adaptation of indigenous iron-and sulfur-oxidizing bacteria, the pre-acidification the sludge to pH 6.0 and the addition of energy substrates. Results showed the inoculation of mixture of ingenuous iron- and sulfur-oxidizing bacteria and co-addition of Fe^2 and elemental sulfur accelerated acid production and increase of oxidation-reduction potential originating from the bio-oxidation of Fe2^+ and elemental sulfur. Dissolved Cr concentration increased concomitant with pH decreased in the sludge and reached its maximum removal of 95.6%. The amelioration of the odor of bioleached sludge could be noted. However, 20.4%o of N, 24.5% of P and 14.3% of organic matter were lost in the bioleaching process. The residual Cr content in the leached tannery sludge was acceptable for use in agriculture. This study had shown the feasibility of applying the bioleaching process, developed for sewage sludge, to tannery sludge with high Cr.  相似文献   

17.
冰川高程变化是冰川形态变化的重要特征之一,能为推算冰川体积变化及物质平衡提供基本参数。利用Sentinel-1A雷达数据,与SRTM数据进行差分干涉,得到2000—2018年哈尔里克山冰川高程变化结果。为进一步提高监测结果的可靠性,以裸地区域的高程变化量作为系统误差修正值,对冰川高程变化结果进行第一次优化。由于差分干涉结果受地形影响较大,为降低地形因素对高程变化的影响,分析地形因子与高程变化标准差之间的关系,去除标准差过大的冰川区域,提高冰川高程变化可靠性,对冰川高程变化结果进行第二次优化,并在此基础上进行精度评定。结果表明:过去18年来,哈尔里克山冰川高程平均下降(8.74±0.14) m;分析冰川高程变化的空间差异性,发现西北部冰川高程减少程度较东南部小;分析冰川高程变化与海拔的关系,发现总体上冰川高程下降程度随海拔升高而减小。  相似文献   

18.
The maize orange leafhopper Cicadulina bipunctata is distributed widely in tropical and subtropical regions of the Old World and feeds on various Poaceae. The leafhopper is recognized as an important pest of maize in several countries. Adults as well as nymphs of C. bipunctata induce growth stunting and galls characterized by the severe swelling of leaf veins on many cereal crops including wheat, rice, and maize, but do not on barley. To clarify the mechanism of growth stunting and gall induction by C. bipunctata, we used six barley chromosome disomic addition lines of wheat (2H–7H) and investigated the effect of barley (cv. Betzes) chromosome addition on the susceptibility of wheat (cv. Chinese Spring) to feeding by the leafhopper. Feeding by C. bipunctata significantly stunted the growth in 2H, 3H, 4H, and 5H, but did not in 6H and 7H. The degree of gall induction was significantly weaker and severer in 3H and 5H than in Chinese Spring, respectively. These results suggest that barley genes resistant to growth stunting and gall induction exist in 6H and 7H, and 3H, respectively. 5H is considered to be useful for future assays investigating the mechanism of gall induction by this leafhopper because of the high susceptibility to the feeding by C. bipunctata. Significant correlation between the degrees of growth stunting and gall induction was not detected in the six chromosome addition lines and Chinese spring. This implies that these two symptoms are independent phenomena although both are initiated by the feeding of C. bipunctata.  相似文献   

19.
The microwave radiation oxidation process, Fenton as catalytic agent, was used to remove the thiocyanate from the industrial wastewater. The effects of microwave power, radiation time, pH and the feeding in ways of catalyst on the degradation rate of synthetic wastewater were investigated using the microwave radiation oxidation process by orthogonal experiment. The results show Fenton catalyst ratio was 1:20, the microwave radiation power was 900 W, the microwave radiation time was 7 min and the value of pH was 3. Under the optimum conditions, the removal of KSCN can reach over 90%. The apparent kinetics of removal was studied, which conformed to kinetics first-class reaction. In short, for the thiocyanate from the industrial wastewater, microwave-Fenton oxidation method is feasible and effective.  相似文献   

20.
The microwave radiation oxidation process, Fenton as catalytic agent, was used to remove the thiocyanate from the industrial wastewater. The effects of microwave power, radiation time, pH and the feeding in ways of catalyst on the degradation rate of synthetic wastewater were investigated using the microwave radiation oxidation process by orthogonal experiment. The results show Fenton catalyst ratio was 1:20, the microwave radiation power was 900 W, the microwave radiation time was 7 min and the value of pH was 3. Under the optimum conditions, the removal of KSCN can reach over 90%. The apparent kinetics of removal was studied, which conformed to kinetics first-class reaction. In short, for the thiocyanate from the industrial wastewater, microwave-Fenton oxidation method is feasible and effective.  相似文献   

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