EGSB-CANON工艺启动及动力学特性

采用EGSB（Expanded Granular Sludge Bed）反应器,在启动全程自养脱氮（CANON）工艺中通过改变曝气方式以及优化曝气/非曝气逐步实现CANON工艺的稳定运行.通过研究不同曝气/非曝气条件下CANON工艺的脱氮性能的变化,探究系统内不同污泥粒径中功能菌的活性,揭示EGSB反应器不同的运行条件以及系统内不同粒径的微生物聚集体在CANON工艺启动过程中的影响机制与菌群结构特性.结果表明,当恒定曝气量为0.5L/min,曝气/非曝气为2：1（60min：30min）时,实现了AerAOB（Aerobic Ammonia-Oxidizing Bacteria）与AnAOB（Anaerobic Ammonium-Oxidation Bacteria）协同脱氮的目的,并成功将NOB（Nitrite-Oxidizing Bacteria）的活性由3.41mgN/（h·gVSS）抑制到0.75mgN/（h·gVSS）.在对AnAOB的双底物（NO₂^--N和NH₄⁺-N）抑制动力学结果进行Haldane拟合时,得到NH₄⁺-N和NO₂^--N的半饱和常数（k_s）、抑制动力学常数（k_h）分别为106.8,331.9mg/L,272.4,66.61mg/L,相关性系数（R²）分别为0.98133和0.99142.在CANON污泥颗粒化形成过程中,污泥粒径在0.154~0.335mm范围内主要以AerAOB为主,污泥粒径在1mm以上主要以AnAOB为主.不同粒径下微生物聚集体的协同作用以及稳定的群落结构实现了CANON工艺的稳定运行.     

从造纸污泥中提取木质素制备缓蚀阻垢剂

以造纸污泥为原料,用碱溶酸析法提取其中的木质素,对木质素进行磺化改性后,与有机磷、锌盐等进行复配,以提高缓蚀阻垢效果。探讨了主原料配比、药剂投加量、反应温度、反应时间等对药剂性能的影响。结果表明:由该法制备的缓蚀阻垢剂性能较好,为造纸污泥的综合利用提供了一条新途径。     

Enhanced anaerobic treatment of CSTR-digested effluent from chicken manure: The effect of ammonia inhibition

The effect of ammonia inhibition was evaluated during the enhanced anaerobic treatment of digested effluent from a 700 m³ chicken-manure continuous stirred tank reactor (CSTR). A 12.3 L internal circulation (IC) reactor inoculated with an anaerobic granular sludge and operated at 35 ± 1 °C was employed for the investigation. With a corresponding organic loading rate of 1.5-3.5 kg-COD/m³ d over a hydraulic retention time of 1.5 d, a maximum volumetric biogas production rate of 1.2 m³/m³ d and TCOD (total COD) removal efficiency ranging from 70% to 80% was achieved. However, the continual increase in the influent TAN content led to ammonia inhibition in the methanogenesis system. The SCOD/TAN (soluble COD/total ammonia nitrogen) ratio was presented to be the key controlling factor for the anaerobic treatment of semi-digested chicken manure, and further validation through shock loading and ammonia inhibition experiments was conducted. The threshold value of the SCOD/TAN ratio was determined to be 2.4 (corresponding to a TAN of 1250 mg/L) at an influent pH of 8.5-9.     

工业废水厌氧生物处理中的无机和有机毒性物质

介绍了有关工业废水厌氧生物处理中无机和有机毒性物质方面的重要研究成果。工业废水中的毒性物质一般会对甲烷菌产生可逆性抑制,驯化能够减轻或消除毒性物质对甲烷菌的抑制作用,厌氧工艺在适当条件下能够有效地去除工业废水中的多种毒性物质。     

厌氧流化床反应器处理含硫废水毒性的实验

采用多孔聚合物载体固定化微生物在厌氧流化床（AFB）反应器中处理含硫废水,研究反应器抗硫化物（S^2－）毒性抑制和抗硫酸盐毒性抑制的能力;探索解除 S^2－毒性的方法．研究表明,当进料基质 COD浓度为 5000mg/L,HRT为5.2－5.4h,S^2－＜200mg/L时,反应器去除 COD效果不受影响,S^2－350mg/L时,厌氧消化受到明显抑制,反应器可容忍530mg/L S^2－浓度而未造成消化系统的破坏;SO₄^2－浓度高达3521mg/L,COD去除率仍可达77％－80％,但SO₄^2－去除率明显下降;当COD/SO₄^2－的比值大于1.45时,硫酸盐还原菌和产甲烷菌的生长未受到明显抑制,此时容积负荷为22－24kgCOD/（m³>·d）,COD去除率为80％,SO₄^2－去除率为58.8％;向反应器投加适量FeCl₂可很好地解除S^2－的抑制．     

A comparative study of classical and biochemical endpoints for phytotoxicity testing of chlorobenzoic acids

IntroductionChlorobenzoic acids ( CBAs ) are important chemicalproducts and extensive used as the intermediate and analysisreagent in many industrial fields(Zhang, 2001). Therefore,CBAs may directly and constantly release into environment,and it was a…     

Qualitative analysis and quantitative simulation on Yin-Huang water salinization mechanism in Bei-Da-Gang reservoir

Yellow River water transfer for Tianjin is important in solving the water shortage in Tianjin, which facilitate economic development and social progress for many years. Fresh water drawn from Yellow River（ i. e., Yin-Huang water） becomes saltier and saltier when being stored in the Bei-Da-Gang reservoir. We qualitatively analyze the water salinization mechanism based on mass transfer theory. The main factors are salinity transfer of saline soil, evaporation concentrating, and the agitation of wind. A simulative experimental pond and an evaporation pond were built beside the Bei-Da-Gang reservoir to quantitatively investigate the water salinization based on water and solute balance in the simulative pond. 80% of increased [Cl^-] is due to the salinity transfer of the saline soil and the other 20% is due to evaporation concentrating, so the former is the most important factor. We found that the salinization of Yin-Huang water can be described with a zero-dimension linear model.     

C9-AA水溶性石油树脂的制备及其阻垢性能

以乙烯生产过程中的副产物C9馏分和丙烯酸为原料,采用自由基溶液聚合,合成具有阻垢性能的C9-AA水溶性石油树脂。考察了引发剂AIBN和溶剂的加入量、C9-AA加入量、Ca^2＋浓度、循环冷却水pH和养护时间对C9-AA水溶性石油树脂阻垢性能的影响,并对其阻垢效果进行了评价。在Ca^2＋质量浓度小于或等于600mg／L、循环冷却水pH小于或等于9．3、C9-AA水溶性石油树脂加入量大于或等于15mg／L的条件下,C9—AA水溶性石油树脂对循环冷却水的阻垢率达到90％以上,其有效作用时间为60h。     

Characterization of the toxic effects of cadmium and 3.5-dichlorophenol on nitrifying activity and mortality in biologically activated sludge systems—effect of low temperature

Background, aims, and scope  Sometimes, urban wastewaters convey a more or less significant part of toxic products from industries or the craft industry. Nitrifying activity can be affected by these substances, implying higher ammonia concentrations in the outlet effluent and contributing to toxicity for the aquatic environment. Moreover, the more stringently treated wastewater standards now require a reliable treatment for nitrogen. One of the key issues is the identification of the inhibition behavior of nitrifying bacteria facing a toxic substance. This new understanding could then finally be integrated into models in order to represent and to optimize wastewater treatment plants (WWTP) operation in cases involving ‘toxic scenarios’. Materials and methods  The toxic substances studied in this work, cadmium and 3.5-dichlorophenol (3.5-DCP), are representative of chemical substances commonly found in municipal sewage and industrial effluents and symbolize two different contaminant groups. The effects of Cd and 3.5-DCP on nitrification kinetics have been investigated using respirometry techniques. Results  IC50 values determination gives concentrations of 3.1 mg/L for 3.5-DCP and 45.8 mg/L for Cd at 21 ± 1°C. The variation to low temperature seems to have no real effect on IC50 for DCP, but induces a decrease of cadmium IC50 to 27.5 mg/L at 14°C. Finally, specific respirometric tests have been carried out in order to determine the potential effect of these toxic substances on the nitrifying decay rate b _a . No significant effect has been noticed for Cd, whereas the presence of 3.5-DCP (at IC50 concentration) induced a dramatic increase of b _a at 20°C. The same behavior has been confirmed by experiments performed in winter periods with a sludge temperature around 12°C. Discussion  The target substances have different modes of action on activity and mortality, notably due to the abilities of the contaminant to be precipitated, accumulated, or even to be progressively degraded. Studies realized at low temperature confirmed this assumption, and put in evidence the effect of temperature on toxic substances capable of being biosorbed. However, the change in the sludge sample characteristics can be pointed out as a problem in the investigation of the temperature effect on nitrification inhibition, as biosorption, bioaccumulation, and predation are directly linked to the sludge characteristics (VSS concentration, temperature) and the plant operating conditions (loading rates, sludge age, etc.). Conclusions  This work brings new understandings concerning the action mode of these specific contaminants on nitrifying bacteria and, in particular, on the role of temperature. The experiments lead to the determination of the IC50 values for both toxic substances on biological nitrification. The inhibition mechanisms of Cd and 3.5-DCP on nitrifying activity have been simply represented by a non-competitive inhibition model. Recommendations and perspectives  Other experiments carried out in a continuous lab-scale pilot plant should be done with a proper control of the operating conditions and of the sludge characteristics in order to better understand the mechanisms of nitrification inhibition for each contaminant. Finally, these first results show that toxic substances can have an effect on the growth rate but also on the decay rate, depending on the characteristics of the toxic substance and the sludge. This eventual double effect would imply different strategies of WWTP operation according to the behavior of the contaminant on the bacteria.     

自催化法合成聚天冬氨酸

以马来酸酐和乙酸铵为原料,在微波条件下用自催化法合成了聚天冬氨酸（PASP）。通过正交实验确定了最佳合成条件：n（乙酸铵）：n（马来酸酐）=1．2,微波功率为1200W,反应时间为10min。在最佳合成条件下,PASP的收率为91．6％,PASP的黏均相对分子质量约为1．5×10^4。经红外光谱表征和核磁共振氢谱测试结果表明,PASP的各种主要官能团表现明显。当Ca^2＋质量浓度为250mg／L、PASP加入量为3mg／L时,PASP的阻垢率达到95％,表明PASP具有较好的阻垢性能。