热泵蒸发及其在浓缩垃圾渗滤液中应用的初探

在热泵蒸发过程中,二次蒸汽压缩比是个至关重要的参数,它直接关系到热泵蒸发的经济程度。对热泵蒸发中的传热过程及可利用的余热作了全面分析。最后对热泵蒸发在浓缩垃圾渗滤液中的应用进行了探讨。     

Electropolymerized poly（Toluidine Blue）-modified carbon felt for highly sensitive amperometric determination of NADH in flow injection analysis

Poly(pheniothiazine) films were prepared on a porous carbon felt (CF) electrode surface by an electrooxidative polymerization of three phenothiazine derivatives (i.e.,Tthionine (TN), Toluidine Blue (TB) and Methylene Blue (MB)) from 0.1 mol/L phosphate buffer solution (pH 7.0). Among the three phenothiazies, the poly(TB) film-modified CF exhibited an excellent electrocatalytic activity for the oxidation of nicotinamide adenine dinucleotide reduced form (NADH) at +0.2 V vs. Ag/AgCl. The poly(TB) film-modified CF was successfully used as working electrode unit of highly sensitive amperometric flow-through detector for NADH. The peak currents (peak heights) were almost unchanged, irrespective of a carrier flow rate ranging from 2.0 to 4.1 mL/min, resulting in the measurement of NADH (ca. 30 samples/hr) at 4.1 mL/min. The peak current responses of NADH showed linear relationship over the concentration range from 1 to 30 mol/L (sensitivity: 0.318 A/( mol/L); correlation coefficient: 0.997). The lower detection limit was found to be 0.3 mol/L (S/N = 3).     

Effects of various pretreatment methods on mixed microflora to enhance biohydrogen production from corn stover hydrolysate

Effects on mixed microflora to enhance biohydrogen production from corn stover hydrolysate was studied.     

Desulfurization of dibenzothiophene（DBT） by a novel strain Lysinibacillus sphaericus DMT-7 isolated from diesel contaminated soil

A new bacterial strain DMT-7 capable of selectively desulfurizing dibenzothiophene (DBT) was isolated from diesel contaminated soil. The DMT-7 was characterized and identified as Lysinibacillus sphaericus DMT-7 (NCBI GenBank Accession No. GQ496620) using 16S rDNA gene sequence analysis. The desulfurized product of DBT, 2-hydroxybiphenyl (2HBP), was identified and confirmed by high performance liquid chromatography analysis and gas chromatography-mass spectroscopy analysis respectively. The desulfurization kinetics revealed that DMT-7 started desulfurization of DBT into 2HBP after the lag phase of 24 hr, exponentially increasing the accumulation of 2HBP up to 15 days leading to approximately 60% desulfurization of the DBT. However, further growth resulted into DBT degradation. The induced culture of DMT-7 showed shorter lag phase of 6 hr and early onset of stationary phase within 10 days for desulfurization as compared to that of non-induced culture clearly indicating the inducibility of the desulfurization pathway of DMT-7. In addition, Lysinibacillus sphaericus DMT-7 also possess the ability to utilize broad range of substrates as sole source of sulfur such as benzothiophene, 3,4-benzo DBT, 4,6-dimethyl DBT, and 4,6-dibutyl DBT. Therefore, Lysinibacillus sphaericus DMT-7 could serve as model system for efficient biodesulfurization of diesel and petrol.     

Experimental studies on ozonation of ethylenethiourea

The experimental study on ozonation of ethylenethiourea(ETU) is conducted.The reaction of gas-phase ETU with 0.63 × 10-6 mol/L ozone is carried out in a 200-L reaction chamber.The secondary organic aerosol(SOA) resulted from the ozonation of gas-phase ETU is observed with a scanning mobility particle size(SMPS).The rapid exponential growth of SOA reveals that the atmospheric lifetime of ETU vapor towards ozone reaction is less than four days.The ozonation of dry ETU particles,ETU-contained water droplets an...     

优质发酵酒精生产酒糟废水回用技术研究

研究以控制优质发酵酒精贸易中二叶恶烷限量为目标,通过实验室模拟研究了不同水源做工艺拌料水时酒精中二叶恶烷含量对比,确定地下水为优质发酵酒精生产的工艺用水;研究了酒糟污水处理后SBR水对酒精发酵质量影响;将小试结论用于酒精生产的实际工艺,产品中二叶恶烷含量检测表明,60%SBR水40%地下水能够满足优质酒精的工艺用水要求。对SBR水反复回用3次后,酒精中二噁烷含量仍处于较低水平,能够满足优质酒精贸易中二叶恶烷限量的要求。     

2008年奥运期间北京不同粒径大气颗粒物中元素碳和有机碳的变化特征

采用安德森撞击式分级采样器采集2008-06-01～2008-09-30不同粒径的大气颗粒物样品,并用美国沙漠所DRI(desert research institute)的Model 2001A热光碳分析仪对其中的元素碳和有机碳进行了分析.结果表明,平均有56%、55%和73%的PM、OC和EC富集于粒径<2.1 μ...     

三种重金属离子及EDTA二钠对虾夷扇贝幼虫急性毒性效应的研究

在实验室条件下研究了Cu2+、Pb2+、Cr6+和EDTA二钠盐对虾夷扇贝面盘幼虫的急性毒性效应,考察了毒物浓度对其存活、发育的影响,计算出几种毒物24 h、48 h,96 h的LC50,并根据96 h LC50得到Cu2+的安全浓度为0.0027 mg/L,pb2+的安全浓度为0.0914 mg/L,Cr6+的安全浓...     

Toxic effects on adult male zebrafish（Danio rerio） following co-exposure to tris-（2,3-dibromopropyl） isocyanurate and 17 β-estradiol

三-（2,3-二溴丙基）异氰脲酸酯（TBC）是近年来在环境中新检测到的一种杂环溴化阻燃剂,但其毒性效应尚不明确.我们以雄性斑马鱼为受试动物,开展了TBC和17β-雌二醇（E2）的复合暴露实验,以研究TBC潜在的致毒机制.结果显示TBC可显著抑制E2所引起的斑马鱼肥满度指数上升,并能改善E2暴露所造成的斑马鱼精子细胞比例降低和性腺发育迟缓;E2暴露可造成斑马鱼肝组织脂肪样病变,肝中MDA含量上升,但SOD活力没有显著改变;TBC复合暴露后,MDA含量呈现下降趋势,但鱼肝仍有明显的脂肪样病变,对肝脏中的SOD活力也没有显著影响;更重要的是,TBC可显著抑制E2单一暴露所诱导的雄鱼肝脏中卵黄蛋白原基因的表达,这些数据表明TBC具有明显的内分泌干扰效应.因此,需要进一步关注TBC这类杂环溴化阻燃剂对水环境的潜在危害.     

基于数值仿真-响应表面法的二沉池优化研究

以长沙市某污水处理厂二沉池为例,采用多相流混合物模型与k-ε湍流模型结合对辐流式二沉池内速度场和污泥浓度场进行了数值模拟.以出水口悬浮物浓度(SS)为响应目标,对影响二沉池沉淀效果的3个影响因素(进水口流速、颗粒污泥粒径、挡板的淹没深度)进行中心复合设计(central composite design,CCD),并经响应表面法分析得到影响出水SS的二次回归模型,确定了二沉池沉降的最佳条件:进水口流速为0.03m·s-1,颗粒污泥粒径为220.41μm,挡板的淹没深度为3.45m,采用数值仿真模拟实验得到出水口悬浮物浓度值为2.4mg·L-1,较优化之前的仿真结果一周平均值6.7mg·L-1相比,其处理效率提高了64.2%.采用数值仿真和响应表面法结合对二沉池工艺条件进行优化研究,可以加速寻优过程,是工艺优化的辅助工具.