温度对好氧颗粒污泥处理纤维素乙醇废水脱氮效能的影响

采用SBR反应器,考察了温度对好氧颗粒污泥处理纤维素乙醇废水脱氮性能的影响.研究结果表明,当进水为纤维素乙醇废水原水时,稳定阶段不同温度(10、20、30℃)条件下体系对COD的去除率分别为10.2%、12.7%、13.7%;总无机氮的去除率分别为42.8%、53.6%、70.5%,温度的升高明显地提高了硝化菌的活性和生长速率,进而促进了脱氮效果.当进水为纤维素乙醇废水经IC工艺处理后的厌氧出水时,3个温度条件下系统对废水中有机物的去除效果无较大差异,去除率均低于15%,主要因为纤维素乙醇废水的厌氧处理出水中的有机物很难被微生物利用;而温度对脱氮效果影响较大,30℃下NH_4~+-N去除率达到60.9%,分别是10℃和20℃时的2.0和1.3倍,并且,随着温度的升高总无机氮的去除率增强,NO_3~--N的去除量增加.由于体系COD去除率低说明反硝化可利用的碳源不足,因此,系统内可能存在内碳源反硝化作用,而且内碳源反硝化作用也随着温度的升高而增强.通过氮平衡计算可知,3个温度条件下氮损失分别为37.6%、45.0%、53.6%,说明温度的升高不仅提高了硝化菌活性,还促进了内碳源反硝化,进而提高了对氮素的去除.     

厌氧序批式反应器产氢

以啤酒厂废水处理厂UASB中的厌氧污泥为种泥,葡萄糖为基质,研究了厌氧序批式反应器产氢。控制反应器内pH为4.0～4.5,温度为(36±1)℃,水力停留时间为8 h,当进水葡萄糖浓度为4 000 mg/L,容积负荷为12 kg/(m3.d)条件下,该厌氧序批式反应器实现了连续高效厌氧产氢。生物气中的氢气含量约为48%～53%,基质产氢率为1.1 mol/mol葡萄糖,COD去除率为15%～25%,最大比产氢速率为84.5 mol/(kg VSS.d)。液相末端发酵产物中乙醇和乙酸的含量占液相末端发酵产物总量的80%以上,表明该反应器内进行的是乙醇型发酵厌氧产氢。厌氧序批式反应器完全可以实现连续高效厌氧产氢,比较适用于日处理量较小的高浓度含糖废水。     

升流式厌氧污泥床-接触氧化工艺在酒精废水处理中的应用

介绍了升流式厌氧污泥床 接触氧化工艺在处理高浓度酒精废水中的应用。运行结果表明 ,进水CODCr1 80 0 0～ 2 1 0 0 0mg L ,BOD51 0 50 0～ 1 2 0 0 0mg L ,SS 1 6 0 0 0～ 1 850 0mg L时 ,出水达到GB8978 96二级排放标准。     

顶空气相色谱法同时测定空气中甲醇和乙醇

顶空气相色谱测定空气中甲醇和乙醇含量,以蒸馏水吸收空气中甲醇和乙醇,顶空进样经DB-624毛细管柱分离,氢火焰离子化检测器检测。实际操作证明,该法能满足工业废气和空气中的甲醇和乙醇的监测。     

混燃甲醇和乙醇改善柴油机碳烟排放

以柴油机为基础，以乙醇或甲醇作为预混合燃料，与喷入的柴油组成部分预混的复合燃烧，大幅度降低了发动机排气烟度，同时使氮氧化物排放得到一定改善，发动机的燃油消耗率优于原柴油机，而HC排放，尤其是在低负荷时有所增加，甲醇比乙醇具有降低烟度效果更好、氮氧化物降低更多和HC及CO排入增加较少的优越性。     

新能源汽车在我国发展的可行性分析

本文从我国石油能源短缺和汽车尾气污染环境加剧的背景出发，详细分析了目前主要的各种新能源汽车的特点及在我国发展的前景，最后得出乙醇汽车应是我国发展新能源汽车的最佳选择的结论。     

Ethanol fuels: Energy security,economics, and the environment

Problems of fuel ethanol production have been the subject of numerous reports, including this analysis. The conclusions are that ethanol: does not improve U.S. energy security; is uneconomical; is not a renewable energy source; and increases environmental degradation. Ethanol production is wasteful of energy resources and does not increase energy security. Considerably more energy, much of it high- grade fossil fuels, is required to produce ethanol than is available in the energy output. About 72% more energy is used to produce a gallon of ethanol than the energy in a gallon of ethanol. Ethanol production from corn is not renewable energy. Its production uses more non- renewable fossil energy resources in growing the corn and in the fermentation/distillation process than is produced as ethanol energy. Ethanol produced from corn and other food crops is also an unreliable and therefore a non-secure source of energy, because of the likelihood of uncontrollable climatic fluctuations, particularly droughts which reduce crop yields. The expected priority for corn and other food crops would be for food and feed. Increasing ethanol production would increase degradation of agricultural land and water and pollute the environment. In U.S. corn production, soil erodes some 18- times faster than soil is reformed, and, where irrigated, corn production mines water faster than recharge of aquifers. Increasing the cost of food and diverting human food resources to the costly and inefficient production of ethanol fuel raise major ethical questions. These occur at a time when more food is needed to meet the basic needs of a rapidly growing world population.     

餐厨垃圾混菌发酵制备燃料乙醇

以校园餐厨垃圾为原料,利用根霉和枯草芽胞杆菌进行糖化预处理,再接种啤酒酵母发酵产乙醇。通过单因素实验,以乙醇产量为响应值,对发酵条件进行优化。实验结果表明:乙醇产量最佳的发酵条件为:当底料含水率为22.79%,啤酒酵母接种量为15%,30℃培养条件下,经过5 d发酵,乙醇产量最高可达到6.67%。选用餐厨垃圾丰富了燃料乙醇的取材途径,实现了原材料的多元化,采用微生物预降解原材料为实现高产乙醇奠定了基础。     

快速溶剂萃取-分子筛脱水净化-气质联用法测土壤有机氯农药

用丙酮和正己烷(体积比为1∶1)作溶剂,在100℃和1 500 psi的压力下,用快速溶剂萃取仪从土壤中萃取出有机氯农药,用分子筛进行脱水和净化,GC-MS进行分析,对土壤中有机氯农药进行测定。方法的检出限为0.000 4~0.000 7 mg/kg,曲线的相关系数在0.998以上。对进口标准土进行测定,回收率为77.1%~105.2%,相对误差为-22.9%~5.2%,测定结果在证书允许误差范围内。用硅藻土制成高、中、低3个浓度级别的加标回收和精密度实验,加标回收率为84.3%~101.5%,相对标准偏差为0.6%~11.4%,表明方法准确可靠,方法用于实际土壤测定时发现土壤有不同程度的有机氯农药污染。     

Denitrification potential enhancement by addition of external carbon sources in a pre-denitrification process

The aim of this study is to investigate the denitrification potential enhancement by addition of external carbon sources and to estimate the denitrification potential for the predenitrification system using nitrate utilization rate （NUR） batch tests. It is shown that the denitrification potential can be substantially increased with the addition of three external carbon sources, i.e. methanol, ethanol, and acetate, and the denitrification rates of ethanol, acetate, and methanol reached up to 9.6, 12, and 3.2 mgN/（g VSS.h）, respectively, while that of starch wastewater was only 0.74 mgN/（g VSS,h）. By comparison, ethanol was found to be the best external carbon source. NUR batch tests with starch wastewater and waste ethanol were carried out. The denitfification potential increased from 5.6 to 16.5 mg NO3-N/L owing to waste ethanol addition. By means of NUR tests, the wastewater characteristics and kinetic parameters can be estimated, which are used to determine the denitrification potential of wastewater, to calculate the denitrification potential of the plant and to predict the nitrate effluent quality, as well as provide information for developing carbon dosage control strategy.