某些芳香化合物生物降解性研究

研究了５类３２种芳香化合物生物降解性，选用城市污水场污泥富集的混合菌种做菌源，在好氧生物解实验条件下，苯甲酸类、苯酚类和甲苯是较容易降解的；苯和苯的同系物是可生物降解的；苯磺酸类和含氮芳氮芳香化合物均是难降解的。     

黄土高原近30年植被变化特征及其气候驱动

The use of Normalized difference vegetation index (NDVI) data acquired with multiple satellite sensors has become a necessity in research fields such as agriculture, Land-Use and Land-Cover Change (LUCC) and changes in the natural environment. In this paper, vegetation 10-day composite (VGT-S10) NDVI data with a 1 km×1 km resolution, covering the period from April 1982 to December 2011 and Advanced Very High Resolution Radiometer (AVHRR) Global Inventory Modelling and Mapping Studies (GIMMS) NDVI data with a 8 km×8 km resolution, covering the period from April 1998 to December 2006 were used. The VGT NDVI covering the period from 2007 to 2011 was converted to the GIMMS NDVI for the same period. The vegetation trend during 1982 to 2011 was calculated using the extended NDVI data set. Climate change has a large impact on the vegetation dynamics. A series of statistical analyses were employed to demonstrate the relationship between NDVI and meteorological data during 1982 to 2005. A multiple correlation analysis was applied to validate the association between the two climatic factors and monthly maximum NDVI (MNDVI). The partial correlation coefficient of MNDVI and each climate factor were calculated respectively to describe the singular influence of each meteorological variable. The results indicated that temperature made a significant positive influence on vegetation growth in the whole Loess Plateau. Precipitation is the most important climatic factor that closely correlates with MNDVI, particularly in arid and semi-arid environments. However, in some wet regions, precipitation is not a limiting factor on vegetation growth.     

SBR中生物除磷颗粒污泥的反硝化聚磷研究

反硝化聚磷菌(DNPAOs)可利用厌氧储存的聚.3.羟基丁酸(PHB)以硝酸盐和亚硝酸盐为电子受体进行过量吸磷和反硝化,从而达到在低碳源下脱氮除磷的双重目的.本试验在SBR反应器中,采用厌氧,缺氧/好氧(A/A/O)交替运行的方式.将富集聚磷菌(PAOs)的颗粒污泥成功地诱导为具有反硝化聚磷能力的颗粒污泥.诱导结束后P的去除率在90%以上,NOx-N的去除率在93%以上,厌氧段释磷量在25-33 mg/L,缺氧段每去除lg NOx-N吸收P约1.3 g;典型周期运行结果显示,厌氧段最大比释磷速率(SRPR)为18.39 mg/(g.h),缺氧段最大比吸磷速率(SUPR)为23.72 mg/(g·h),最大比反硝化速率(SDNR)为18.19mg/(g·h),好氧段最大SUPR为17.15 me,/(g·h):颗粒污泥中DNPAOs的数量由诱导前的14.9%增加到80.7%.与除磷颗粒污泥相比.反硝化聚磷颗粒污泥沉速提高0.16-0.7倍,比重提高0.003 1.     

氧化沟反应器流体力学特性的数值模拟与实验研究

采用CFD数值计算和体视PIV测试相结合的方法研究卡鲁塞尔氧化沟反应器流场特性。探索复杂边界条件下反应器流场的模拟方法,采用体视PIV技术分别测量了反应器直道、弯道处三维全场流速;研究不同位置处纵、横、垂三向的流动结构和沿程分布特点。结果表明,模拟与实验结果较吻合;纵、垂两向的流动分布是决定沟内水力特性的主要因素;横、垂两向的流动是决定污泥沉积位置的主要因数;外沟靠近曝气叶轮直道段的流速分布上大下小,在低速区底部易发生污泥沉积;外沟远离曝气叶轮直道段流速分布上小下大,利于防止泥水分离;弯道段受横比降和横向环流的影响,内侧容易形成低速区或停滞区而发生污泥沉积。     

Molecular characterization and developmental expression patterns of thyroid hormone receptors (TRs) and their responsiveness to TR agonist and antagonist in Rana nigromaculata

Considering some advantages of Rana nigromaculata as an experimental species, we propose that this species, like Xenopus laevis, could be used to assay thyroid hormone（TH） signaling disrupting actions. To validate the utilizability of R. nigromaculata, we investigated the responsiveness of R. nigromaculata to a TH receptor（TR） agonist（T3） and antagonist（amiodarone） by analyzing expression, based on characterizing TR cDNA and developmental expression patterns. With high levels of identity with the corresponding genes in X. laevis, both TRα and TRβ in R. nigromaculata exhibited roughly similar developmental expression patterns to those of X. laevis, in spite of some species-specific differences. Both TRα and TRβ expression had greater changes in the liver and intestine than in the tail and brain during metamorphosis. T3 exposure for 2 days induced more dramatic increases of TRβ expression in stage 27 than in stage34 tadpoles but not in stage 42 tadpoles, showing that the responsiveness of R. nigromaculata to TH decreased with development and disappeared at the onset of metamorphic climax.Corresponding to greater changes of TRβ expression in the liver and intestine than in the tail and brain during metamorphosis, the liver and intestine had higher responsiveness to exogenous T3 than the tail and brain. Amiodarone inhibited T3-induced TRβ expression. Our results show that R. nigromaculata can be used as a model species for assaying TH signaling disrupting actions by analyzing TRβ expression, and intestine tissues at stage 27 are ideal test materials due to high responsiveness and easy accessibility.     

SMT法插标分析沉积物中磷的地球化学形态

SMT法是一种较为通用的沉积物磷地球化学形态分析方法,但分析结果的准确性和重现性成为制约其进一步应用的关键.本研究以我国沉积物标准样品GSD-12为标样,在详细研究该标样的SMT法提取的磷的各个地球化学形态含量的基础上,提出了插标法控制沉积物中磷地球化学形态的准确性和可比性.在对比了手工分析,Skalar仪器分析及ICP-MS仪器分析的结果之后,针对SMT法操作中存在的问题进行了探讨,提出了操作过程中的注意事项,提出了GSD-12中总磷(TP)、无机磷(IP)、有机磷(OP)、盐酸提取磷(HCl-P)和氢氧化钠提取磷(NaOH-P)等含量分别为(156±5),(77±2),(39±3),(41±2),(42±2)mg/kg,并将该标样用于太湖沉积物中磷形态测定的质量控制,取得了较为满意的结果.     

水处理用活性炭改性研究

利用锆和氯化十六烷基三甲铵共同改性活性炭,制备一种新型去除污水中硝酸盐和磷酸盐的水处理吸附剂,并考察吸附剂加量、反应温度、pH值、共存阴离子等影响因素对吸附效果的影响。结果表明:锆-氯化十六烷基三甲铵改性活性炭(Zr-CTAC-AC)吸附剂适用于硝酸盐和磷酸盐浓度在100mg/L以下的污水,随着Zr-CTAC-AC加量的增加,硝酸盐、磷酸盐去除率逐渐增加,单位吸附量逐渐下降,Zr-CTAC-AC加量为8g/L时,硝酸盐去除率为79%,Zr-CTAC-AC加量为4.0g/L时,磷酸盐去除率可达91%,但应在较低的pH值范围内使用;反应温度对Zr-CTAC-AC的吸附效果影响不大;共存Cl-、HCO3^-和SO4^2-可使硝酸盐的吸附率降低,但对磷酸盐吸附率影响较小;1mol/L NaCl溶液可使吸附到Zr-CTAC-AC表面的硝酸盐90.9%左右被解吸出来,1mol/L NaOH溶液可使吸附到Zr-CTAC-AC表面的磷酸盐78.4%左右被解吸出来。Zr-CTAC-AC能够有效去除污水中硝酸盐和磷酸盐,制备方法简单,且可循环利用,处理成本低。     

电子废弃物中持久性有机污染物分析检测方法的研究进展

针对目前电子废弃物中持久性有机污染物(POPs)尚未形成有效快速分析检测方法的问题,介绍了溶剂萃取、固相萃取、微波萃取和超临界流体萃取等POPs前处理技术的研究进展,总结了POPs的分析方法,如:气相色谱、液相色谱、气相色谱-质谱法、高分辨率气相色谱-高分辨质谱法等化学分析方法,以及生物传感器测定法、表面胞质团共振检测法、酶联免疫检测法等生物分析方法。分析了各方法的优劣,并提出了展望。     

Cd对不同形态漆酶修复DDT污染土壤的影响

研究了重金属Cd对游离漆酶和同定化反胶团漆酶修复土壤有机氯农药DDT污染的影响.结果表明.游离漆酶对土壤中DDT各组分均有不同程度降解,且均随着cd浓度的增大而降低,含量越高的组分降解率越高.受到Cd污染的影响也越大(P,P'-DDT>P,P'-DDD>0.P'-DDT>P,P'-DDE);当Cd浓度分别为0、0.5、1和2 mg·kg-1时,游离漆酶对土壤中DDT总量的降解率分别为50.68%、32.50%、14.92%和13.40%.固定化反胶团漆酶比游离漆酶能更有效地降解DDT,DDT降解率在无Cd和有Cd存在时(Cd浓度为0.5 mg·kg-1)分别提高20%和30%左右.     

Grazing greatly reduces the temporal stability of soil cellulolytic fungal community in a steppe on the Tibetan Plateau

Excessive livestock grazing degrades grasslands ecosystem stability and sustainability by reducing soil organic matter and plant productivity. However, the effects of grazing on soil cellulolytic fungi, an important indicator of the degradation process for soil organic matter, remain less well understood. Using T-RFLP and sequencing methods, we investigated the effects of grazing on the temporal changes of cellulolytic fungal abundance and community structure in dry steppe soils during the growing months from May to September, on the Tibetan Plateau using T-RFLP and sequencing methods. The results demonstrated that the abundance of soil cellulolytic fungi under grazing treatment changed significantly from month to month, and was positively correlated with dissolved organic carbon (DOC) and soil temperature, but negatively correlated with soil pH. Contrastingly, cellulolytic fungal abundance did not change within the fencing treatment (ungrazed conditions). Cellulolytic fungal community structure changed significantly in the growing months in grazed soils, but did not change in fenced soils. Grazing played a key role in determining the community structure of soil cellulolytic fungi by explaining 8.1% of the variation, while pH and DOC explained 4.1% and 4.0%, respectively. Phylogenetically, the cellulolytic fungi were primarily affiliated with Ascomycota (69.65% in relative abundance) and Basidiomycota (30.35%). Therefore, grazing substantially reduced the stability of soil cellulolytic fungal abundance and community structure, as compared with the fencing treatment. Our finding provides a new insight into the responses of organic matter-decomposing microbes for grassland managements.