UV-B辐射增强对苹果炭疽菌生长特性及其过氧化氢酶活性的影响

在UV-B辐射增强条件下,在UV-B不同剂量率和不同剂量作用下,研究了苹果炭疽菌(Colletrotrichum gloeosporioildes)菌丝的生长速率、产孢性状、分生孢子的萌发特性和过氧化氢酶活性.实验得出,菌落直径、菌丝体干质量、产孢量、分生孢子的萌发及过氧化氢酶(CAT)活性受UV-B的促进,促进作用与剂量率即单位时间内的辐射剂量呈正相关,同一剂量率的不同剂量对苹果炭疽菌的影响没有显著差异.结果表明,UV-B辐射增加,促进了苹果炭疽的生物积累,抗逆性增强,诱导了抗氧化防御系统过氧化氢酶活性,UV-B对苹果炭疽菌的作用不呈累积效应.     

Anoxic phosphorus removal in a pilot scale anaerobic-anoxic oxidation ditch process

The anaerobic-anoxic oxidation ditch (A²/O OD) process is popularly used to eliminate nutrients from domestic wastewater. In order to identify the existence of denitrifying phosphorus removing bacteria (DPB), evaluate the contribution of DPB to biological nutrient removal, and enhance the denitrifying phosphorus removal in the A²/O OD process, a pilot-scale A²/O OD plant (375 L) was conducted. At the same time batch tests using sequence batch reactors (12 L and 4 L) were operated to reveal the significance of anoxic phosphorus removal. The results indicated that: The average removal efficiency of COD, NH4+, PO43-, and TN were 88.2%, 92.6%, 87.8%, and 73.1%, respectively, when the steady state of the pilot-scale A²/O OD plant was reached during 31-73 d, demonstrating a good denitrifying phosphorus removal performance. Phosphorus uptake took place in the anoxic zone by poly-phosphorus accumulating organisms NO2- could be used as electron receptors in denitrifying phosphorus removal, and the phosphorus uptake rate with NO2- as the electron receptor was higher than that with NO3- when the initial concentration of either NO2- or NO3- was 40 mg/L.     

甲醇等5种强极性有机物污染事故中的监测分析方法

建立了在突发性水污染事故中定量分析水样中甲醇、丙酮、乙腈、N,N-二甲基甲酰胺和N,N-二甲基乙酰胺等5种极性有机物的实验室和现场应急监测分析方法。采用顶空-车载气相色谱质谱法用于现场快速定性定量分析;顶空-气相色谱法用于实验室准确定量分析。通过优化顶空及气相参数,在最佳实验条件下测得顶空-气相色谱质谱法中甲醇、丙酮、乙腈、N,N-二甲基甲酰胺、N,N-二甲基乙酰胺等5种化合物的检出限分别为1.0、0.06、0.5、10.0、15.0 mg/L,平行测定7次结果的相对标准偏差分别为2.1%~3.8%,加标回收率为69.4%~104%;顶空-气相色谱法灵敏度高于气相色谱质谱法,检出限分别为0.08、0.01、0.03、1.7、1.7 mg/L,平行测定7次结果的相对标准偏差分别为2.5%~4.1%,加标回收率为78.1%~116%。     

丝孢酵母TX1降酚动力学研究及过程优化

针对自行分离筛选出的高效降酚丝孢酵母菌株TX1,通过不同初始浓度苯酚分批培养系列实验结果和分析,建立其降酚动力学模型,并在此基础上进行过程优化.结果表明,体系的生长动力学可以用Haldane方程描述,其参数分别为μmax=0.667 h-1,KS=51.14 mg/L,Ki=271.7 mg/L.参数说明TX1能较快地...     

膜基材对动态膜生物反应器性能的影响研究

选用5种滤布作为动态膜生物反应器(DMBR)的膜基材在相同操作条件下进行对比实验,考察反应器运行周期、反冲洗前后过滤压力、膜通量的恢复情况,分析DMBR进出水水质.结果表明,应用DMBR处理模拟生活污水,其中孔径为24μm的涤纶短纤滤布组成的DMBR对COD、氨氮和总氮的去除率分别为90%、80%和48%以上;运行周期...     

海藻酸纤维动态吸附废水中亚甲基蓝染料

自制了海藻酸纤维并从动态吸附方面研究了海藻酸纤维对阳离子染料亚甲基蓝的吸附性能,采用2种动力学模型(Thomas模型和Yoon-Nelson模型)对不同浓度的亚甲基蓝染料溶液动态吸附曲线进行了分析.结果表明,Thomas模型和Yoon-Nelson模型对海藻酸纤维吸附亚甲基蓝染料都有较高的拟合度,由2种模型分析得出的海...     

超声处理与碱性调节的组合强化低挥发分城市污泥水解酸化

为提高低挥发分城市污泥水解酸化的效率,采用超声处理与碱性调节组合的手段强化水解酸化过程,探讨组合的方式、条件及其作用效果。通过先进行碱性调节再超声处理与先超声处理再进行碱性调节2种组合方式下的6种组合条件,分析水解酸化过程SCOD、VFAs、氮、磷的变化情况。实验结果表明,2种组合方式的各条件均可促进污泥水解酸化;超声处理后即调pH为9.5的组合条件较其他组合条件更有利于有机质的转化和VFAs的产生,SCOD的转化率达到20.46%,VSS可降低约40%,在5 d水解酸化过程中污泥水解酸化液HAc/VFAs均高于50%,VFAs最高达1 072.51 mg/L;而各组合条件对水解酸化过程中氮磷的释放影响不大。研究指出,超声处理后即进行碱性调节的组合条件能显著强化低挥发分城市污泥的水解酸化效果。     

稻秆负荷与pH对稻秆厌氧发酵产酸系统启动过程的影响

为探讨稻秆负荷（即稻秆VS/污泥VSS）与发酵pH对稻秆厌氧发酵产酸系统启动过程产挥发性脂肪酸（VFAs）效果的影响,利用厌氧搅拌罐反应系统考察在不同的稻秆负荷（0.556、0.945、1.334和1.724 g/g）和不同的发酵pH（8.0、9.0和10.0）启动运行条件下的产酸性能,并分析了系统启动过程产酸与稻秆主要成分降解之间的关系。实验结果表明,VFAs浓度随稻秆负荷提高而增大,随发酵pH的升高而降低;发酵18 d时,发酵pH为9.0时,稻秆负荷1.334 g/g的产酸效果最好,VFAs浓度与稻秆产酸量分别为4 385.10 mg/L和2.19 gVFAs/g稻秆,此时半纤维素、纤维素和酸性洗涤木质素降解率分别为32.69%、22.53%和6.40%;稻秆负荷为0.945 g/g条件下,VFAs浓度在pH为8.0时达到最高值4 409.51 mg/L,此时稻秆降解量也最多,半纤维素、纤维素和酸性洗涤木质素降解率分别为28.60%、47.32%和22.69%。研究表明,稻秆负荷与发酵pH通过影响稻秆半纤维素、纤维素和木质素的降解影响稻秆厌氧发酵产酸的进程和效果。     

The composition, trend and impact of urban solid waste in Beijing

This paper provides an overview of the trend of generation, composition, and management of municipal solid waste, and estimates the carbon emissions arising from municipal solid waste management in Beijing. The correlation analysis conducted shows that the generation of municipal solid waste in Beijing has been growing steadily, showing high correlations (r > 0.9) to the total GDP, per capita income, and the population. Food waste showed an increasing trend since 1990. Compared with the results of an investigation in 1990, ash and woodchips content in 2003 declined from 56% to 17%, while the percentage of paper and plastic increased from 10% to 29% over the same period. The calorific value of the municipal waste also increased, from 2,686 kJ/kg in 1990 to 4,667 kJ/kg in 2003, indicating that the waste is suitable for incineration. Currently, the source separation ratio of municipal waste is approximately 15%. About 94% of all the collected solid waste goes to the landfill while 4% is composted and 2% is incinerated. A moderate garbage collection fee is applied to both permanent and temporary residents in Beijing, but the willingness to pay for solid waste collection and treatment is still low. Under current treatment mode, the total amounts of carbon emission from waste disposal sites and incineration increased with the increase of municipal solid waste, from 29.8 Gg in 1990 to 84.5 Gg in 2003, including 83.3 Gg of CH₄ and 22.0 Gg of CO₂. The data availability and methodological challenges in monitoring the quantity and characteristics of municipal solid waste are discussed.     

高浓度氨氮对IC厌氧反应器运行的抑制性研究

在中温(35±1)℃条件下,以葡萄糖为有机碳源,研究氨氮对IC厌氧反应器运行的影响.实验结果表明,氨氮浓度超过3 036 mg/L时对反应器的运行有抑制作用,随着氨氮浓度的增加,抑制作用更加明显,氨氮对系统的IC50为4 500 mg/L;系统运行过程中VFA低于400 mg/L,pH值和碱度分别维持在7.21～7.62之间和2 356～3 065 mg/L之间;反应器对氨氮的平均去除率为12.67%.在毒性恢复实验中,7 d后COD去除率恢复到93.01%;恢复期系统VFA逐渐降低,从第6 d开始维持在152～162 mg/L之间;出水碱度和pH值维持在1 769～2 298 mg/L和7.09～7.27之间,系统运行稳定.