内循环一体式工艺同步硝化反硝化的研究

文章提出了一种内循环一体式同步硝化反硝化工艺,它是在反应器中加隔板,将反应器从空间上分成好氧区、缺氧区和沉淀区。实验在连续曝气的条件下,对该工艺同步硝化反硝化脱氮的主要影响因素污泥浓度、水力停留时间、碳氮比和反应区内的溶解氧进行研究。结果表明：污泥浓度为4 g/L左右、水力停留时间为4 h、碳氮比为8.3、溶解氧为2.0 mg/L时,反应器内产生了较好的同步硝化反硝化现象,NH4＋-N和TN去除分别达到95.6%和89.3%。     

Low temperature autoignition of Jet A and surrogate jet fuel

An experimental study of the low-temperature and low-pressure autoignition of Jet A and surrogate fuels was conducted using the ASTM-E659 standardized test method. Two surrogate fuels (Aachen and JI mixtures), their individual components and two batches (POSF-4658 and POSF-10325) of standardized Jet A were tested using the ASTM-E659 method for a range of fuel concentrations and temperatures. The ignition behaviors were categorized into four distinct ignition modes. The individual hydrocarbon components had a wide range of ignition behaviors and minimum autoignition temperatures (AIT) values depending on the molecular structure. The two Jet A batches showed similar ignition behavior with measured AITs of 229 ±3°C and 225 ±3°C respectively. Both surrogates exhibited similar ignition behavior to Jet A with comparable AITs of 219 ±3.1°C (Aachen) and 228 ±3°C (JI) with the JI mixture proving to be a more suitable surrogate to Jet A in the low-temperature thermal ignition regime.     

超声协同紫外灭活大肠杆菌实验研究

应用紫外、超声、超声协同紫外对大肠杆菌进行灭活,并从生物学角度对协同机理进行探讨。结果表明:实验条件下,紫外辐照剂量与大肠杆菌灭活率之间具有良好的线性关系,各紫外辐照剂量下的E.coli均发生了光复活现象。超声功率密度对于灭活结果具有显著意义(p0.05),研究中超声灭活大肠杆菌的最大相对功效值对应的工况为7.18W/cm2作用80s。超声的协同作用使紫外线消毒动力学方程K值由0.1增至0.1358,减小了细菌对UV的抗性;与单独紫外作用比较,超声与紫外协同作用的光复活率有所降低。超声与紫外同时作用对细胞形态结构产生严重的破坏,超声作用只能改变细胞的结构,而不能破坏其DNA;利用T4-EndoⅤ对CPDs的特异性识别特性,可发现经各工况处理后,大肠杆菌DNA均被降解,产生大量CPDS,且各工况下ESS含量变化曲线与各工况下大肠杆菌灭活率曲线的相关系数达到0.92。     

A/O＋硅藻强化新工艺在中小型城镇污水处理中的应用总结

采用A/O＋硅藻精土强化工艺水处理技术对城市生活污水进行处理,工程运行结果表明,处理后的废水能够稳定达到《城镇污水处理厂污染物排放标准》（18918-2002）一级A标准。与其它生物处理工艺相比,有其独特的优点。该工艺已成功地应用于永城市污水处理中心,并获得2008年国家重点环境保护实用技术示范工程。而生物浮动床（MBBR工艺）＋硅藻精土强化工艺是在此基础上的改进,并已成功地应用于污水处理。     

工业废水处理中应用磁性载体技术的研究

本文介绍了采用磁性载体与A／O联合工艺处理南京金陵石化研究院中试车间产生的含表面活性剂废水技术。采用磁性载体取代一般填料对MBBR工艺进行改良,磁性载体完成挂膜后,微生物的活性明显提高污水处理厂处理能力大幅提升。对比不同工艺处理相同污水时,改良MBBR工艺能保证污水能够平稳达标排放,同时提高了污水处理效率,降低了污水处理厂运行成本,提高了污水处理能力。     

草酸促进双酚A在黏土矿物悬浮液中光降解研究

选择两种常见的天然黏土矿物高岭石和蒙脱石,研究了有机污染物双酚A(BPA)在其表面的吸附及草酸对黏土矿物悬浮液中BPA光降解的影响.结果表明,BPA在两种黏土矿物表面的吸附量较小,吸附符合Langmuir等温式.在250W金属卤化物灯(λ≥360nm)照射下,草酸可显著促进BPA在高岭石和蒙脱石悬浮液中的光降解,降解动力学符合Langmuir-Hinshelwood方程. 降解速率受pH值的影响较大,pH=4.0时速度最快,光降解速率同时受草酸浓度的影响.最后,通过分析矿物中铁的化学环境及反应过程中铁浓度变化,分析了草酸促进BPA在黏土矿物悬浮液中光降解的可能机制.     

Microbial community structure in an integrated A/O reactor treating diluted livestock wastewater during start-up period

In order to investigate the correlation between reactor performance and the microorganisms, an integrated A/O reactor was operated for 72 days to treat diluted livestock wastewater. Chemical oxygen demand (COD) removal e ciency increased from 79% to 94%, with total nitrogen (TN) removal e ciency from 37% to 50% (HRT 7.4 hr) when the influent COD and TN were ca. 1500 mg/L and 95 mg/L, respectively, and the outlet COD concentration was less than 100 mg/L at the end. Microbial community was monitored during start-up period by denaturing gradient gel electrophoresis (DGGE) based on 16S rRNA gene. DGGE profiles showed that microbial community had changed significantly during the start-up and these shifts were in accordance with the reactor performance. UPGMA clustering analysis showed that 14 anaerobic samples fell into five main groups and so did the aerobic ones, but the grouping patterns were di erent. Phylogenetic analysis indicated that microbial populations in the anaerobic compartment belonged to Firmicutes, Proteobacteria, Chloroflexi and Bacteroidetes, while Proteobacteria, Bacteroidetes, Firmicutes, Verrucomicrobiae and Nitrospira were present in the aerobic compartment. In the anaerobic compartment, more fermentative and acetogenic bacteria were detected during the start-up while denitrifying bacteria faded away. Two functional populations such as Nitrospira defluvii and Dechloromonas denitrificans were observed when nitrogen removal was high, indicating that simultaneous nitrification and denitrification occurred in the aerobic compartment.     

MBR与A／O工艺处理低温高盐废水的对比试验研究

就MBR和A／O工艺对高盐废水（50％海水）进行处理效果试验研究,比较了氨氮及总氮去除率随温度的变化情况。试验结果表明：低温条件下MBR与A／O工艺经过长期驯化能够稳定运行且获得较高的去除率;随温度从25qC降低到15℃、9℃、5℃时,MBR工艺的COD去除率从81．6％变化到79％、81．1％、82．7％,A／O工艺的COD去除率从67．9％变化到66．6％、65．5％、78．4％。MBR工艺的氨氮去除率从75％变化到68．3％、57．8％、54．6％,A／O工艺的氨氮去除率从70．4％变化到55．9％、49．2％、48．9％,可见COD受温度变化的影响要比氨氮受温度变化的影响小,但经过一段时间的驯化之后,去除效果逐渐变好,并且MBR工艺比A／O工艺受温度变化的冲击要小,处理效果也相对较好。     

Effects of nonionic surfactant Triton X-100 on the laccase-catalyzed conversion of bisphenol A

The laccase-catalyzed conversion of bisphenol A (BPA) in aqueous solutions was studied in the absence and presence of nonionic surfactant Triton X-100. It was found that the addition of Triton X-100 into the reaction system increased the conversion of BPA, especially near the critical micelle concentration of Triton X-100. Also it was found that the stability of laccase was greatly improved in the presence of TritonX-100. Studies on the endogenous fluorescence emission of laccase indicated that there existed an interaction between Triton X-100 and laccase, which was beneficial to folding and stabilizating of laccase. The binding of Triton X-100 to the laccase surface also mitigated the inactivation e ect caused by the free radicals and polymerization products. Under otherwise identical conditions, a lower dosage of laccase was needed for the higher conversion of BPA in the presence of Triton X-100.     

A/O生物脱氮工艺内循环回流和外碳源投加综合控制的优化

为了提高A/O工艺反硝化效果,应用COST/IWA-Benchmark基准对5种内循环回流量和外碳源投加综合控制策略进行了比较.结果表明,控制策略1无论从外碳源消耗量、出水水质,还是从控制器稳定性上都是最优的控制策略,它有2个反馈环路组成,一个环路控制外碳源投加量,从而维持缺氧区出水硝酸氮浓度处于最优设定值2mg/L,另外一个环路控制内循环回流量,维持好氧区出水硝酸氮浓度(根据排放标准确定,一般为8～12mg/L).该策略在低负荷时可以高效利用缺氧区反硝化容量,而在高负荷时通过控制外碳源投量保证出水硝酸氮满足排放标准.