Effects of humic acids derived from lignite and cattle manure on antioxidant enzymatic activities of barley root

To investigate the effects of humic acids (HAs) on the ability of plants to defend themselves against oxidative stress, barley was hydroponically cultured in the absence and presence of HAs, and the antioxidant enzymatic activities (catalase, superoxide dismutase, ascorbate and glutathione peroxidases) of root tissue were evaluated. Auxin-like structures in HAs, which were extracted from an oxidation product of lignite (LHA) and compost derived from cattle manure (CHA), were identified by pyrolysis-gas chromatography/mass spectrometry (GC/MS) with tetramethylammonium hydroxide. The LHA, which had the lower molecular weight, was more effective in promoting the growth of barley root than CHA. However, the amounts of auxin-like structures in the CHA were much higher than those for LHA. The antioxidant enzymatic activities were initially decreased in the presence of LHA and CHA at the first day after refreshing the culture solution, but were significantly increased on the second day. The CHA sample, which contained relatively high levels of phenolic acids that contained auxin-like structures, was effective in increasing four types of enzymatic activities, while the activities of catalase and ascorbate peroxidase were increased in the presence of LHA, which contains naphthalene derivatives. These results indicate that using HAs as a supplement can be effective in enhancing antioxidation enzymatic activities, while the appearance of the effects is retarded because of the decomposition and release of auxin-like compounds from HAs by organic acids from the plant roots.     

Racemic,R-, and S-tebuconazole altered chitinase and chitobiase activity of Daphnia magna

Tebuconazole is a chiral trizole fungicide and widely used in many crops for controlling disease. Tebuconazole is potential toxic to some aquatic organisms but relative information of its isomers is scarce. To detect the endocrine disrupting effects and difference of rac-, R-, and S-tebuconazole, the chitinase activity in Daphnia magna and chitobiase activity in each test medium were used as biomonitors after a 14-day exposure. Results showed that chitinase activity was significantly reduced by rac-, R-, and S-tebuconazole. The chitobiase activity in the test medium was reduced by rac- and R-tebuconazole before day 10, and only one peak was observed at day 10 or day 12 compared with two obvious peaks in the control group (days 6 and 12). S-tebuconazole delayed and reduced the reproduction of D. magna, but did not delay the first chitobiase activity peak, whereas the second peak could not be characterized as the exposure concentration and time increased. Compared with chitinase activity, chitobiase activity can still be used as a rudimentary model for identifying molt-interfering xenobiotics, and further studies should focus on the analysis of correlations between these parameters.     

Effects of degree of water saturation on dispersivity and immobile water in sandy soil columns

Three natural nonaggregated soil samples, with similar grain-size distributions, have been used to determine the dispersive behavior of porous media under steady, saturated and unsaturated flow conditions. Tritium was used as a tracer and was found to have no sorption on the solid matrix. Generated breakthrough curves (BTCs) for the unsaturated experiments were symmetrical with no evidence of tailing. The unsaturated experiments for two of the soils were adequately described by considering all the water in the pore volume as mobile. However, about 10% of the pore water, independent of the degree of saturation, was found to be immobile in the case of the third soil during unsaturated flow. For this soil, there was no mass transfer between the two water regions, indicating that the immobile water is essentially isolated from the flowing water fraction. For all three soils, dispersivity under unsaturated conditions was found to be higher, independent of the degree of water saturation, than the value determined for the saturated experiments. This is inconsistent with what would be expected from the simple bundle-of-capillary-tubes model and does not agree well with a more sophisticated conceptualization of the porous medium. The data, however, clearly indicate a wider range in pore-water velocities when these soils are desaturated.     

环糊精在环境科学中的应用

本文从环糊精对有机污染物的增溶作用：环糊精用于环境中有机污染物的富集和去除;环糊精对有机污染物降解过程的影响;环糊精衍生物去除土壤中的重金属;环糊精对污染物生物活性的影响等几个方面讨论了环糊精在环境科学方面的应用。     

错流式动态膜-生物反应器中污泥活性的研究

应用错流式动态膜-生物反应器(CDMBR)对己内酰胺废水进行了180 d的实验,实验过程中测定反应器的膜出水和上清液的水质,并对污泥进行了耗氧呼吸速率测定.结果表明,上清液COD一直保持在100mg/L以下,而膜出水的则保持在50 mg/L以下,膜对上清液的COD去除率达50%,而对氮的去除没有贡献.可溶性细胞产物(SMP)在反应器内容易积累,停留足够的时间后能被生物降解.通过投加抑制剂测定耗氧呼吸速率,发现异养菌、硝化细菌和亚硝化细菌的活性由于F/M的降低和SMP积累受到一定的抑制,但不影响系统的处理效率.跨膜压力、膜面流速越大,通量衰减得也就越快.     

Determination of microbiological contamination,antibacterial and antioxidant activities of natural plant hazelnut (Corylus avellana L.) pollen

The aim of our study is to determine microbial contamination, antibacterial and antioxidant activities of 14 pollen samples of Corylus avellana collected from different locations in Slovakia. Microbiological analysis was carried out in two steps: microbiological assays and studies of antibacterial activity of pollen extracts. The antimicrobial properties of pollen extracts were carried out with the disc-diffusion method. Methanol (70%), ethanol (70%) and distilled water were used for pollen extracts. Five strains of bacteria such as gram-negative (Salmonella enterica subsp. enterica CCM 3807, Escherichia coli CCM 2024, and Yersinia enterocolitica CCM 5671) and gram-positive (Staphylococcus aureus CCM 2461 and Bacillus thuringiensis CCM 19T) were tested. Antioxidant activity of pollen extracts was determined by the DPPH method. Bacterial analysis includes the determination of the total bacterial count ranged from 4.08 to 4.61 log CFU g^?1, mesophilic aerobic bacteria ranged from 3.40 to 4.89 log CFU g^?1, mesophilic anaerobic bacteria ranged from 3.20 to 4.52 log CFU g^?1, coliform bacteria ranged from 3.30 to 4.55 log CFU g^?1, yeasts and filamentous fungi ranged from 3.00 to 3.56 log CFU g^?1. Microscopic filamentous fungi Aspergillus spp., Alternaria spp., Penicillium spp., Cladosporium spp., Rhizopus spp., and Paecylomyces spp. were isolated from hazelnut pollen. Yersinia enterocolitica was the most sensitive strain among ethanolic and methanolic pollen hazelnut extracts. Staphylococcus aureus was the most sensitive strain against aqueous hazelnut pollen extracts. We determined the following sensitivity against ethanol pollen extracts respectively: Yersinia enterocolitica?>?Salmonella enterica?>?Staphylococcus aureus?>?Bacillus thuringiensis?>?Escherichia coli. Methanol pollen extracts had shown following sensitivity: Yersinia enterocolitica?>?Salmonella enterica?>?Escherichia coli?>?Staphylococcus aureus?>?Bacillus thuringiensis. Aqueous extracts had shown the following sensitivity: Staphylococcus aureus?>?Salmonella enterica?>?Escherichia coli?>?Bacillus thuringiensis?>?Yersinia enterocolitica. Hazelnut pollen extracts have over 82% antioxidant capacity in samples from non-urban zones. An elevated level of antioxidant potential in the pollen is determined by its biological properties conditioned by biologically active substances. DPPH method allowed characterizing pollen as a source of antioxidants.     

TiO2/PANI/Fe3O4光催化磁流体的全流态合成及其光催化和磁回收性能

以Fe3O4磁流体为磁核,经微乳液聚合包覆聚苯胺后制成催化剂载体,再采用低温水热法合成TiO2并使其负载于载体表面,不经过烘干、研磨等步骤,在全程流态的情况下制备出具有复合结构的TiO2/PANI/Fe3O4光催化磁流体。用X射线衍射仪（XRD）、透射电子显微镜（TEM）、扫描电子显微镜（SEM）、傅里叶红外分光光度计（FT-IR）、振动样品磁强计（VSM）对样品的物相组成、形貌、表面性质和磁学性质进行了表征。以苯酚为模拟污染物,评价其光催化活性;通过自制的磁回收装置,考察其磁回收特性。结果表明：在表面活性剂以及微乳液聚合法的作用下,合成反应过程中的团聚现象得到有效的抑制。在不经过烘干、研磨的条件下,制备出了颗粒均匀、催化活性和磁回收性能良好的TiO2/PANI/Fe3O4光催化磁流体。不仅简化了合成的步骤,同时也避免了研磨等物理作用对催化剂结构的破坏,为光催化磁流体的合成提供了新的思路。     

TiO2、BiVO4、Cu2O光催化降解低浓度甲醛

比较研究了3种（TiO2,BiVO4,Cu2O）光催化剂对低浓度甲醛的降解过程,拟通过结构分析（晶粒尺寸、比表面积、禁带宽度）和实验评价其性能优劣,优选出光催化性能较好的材料。通过结构分析和降解甲醛实验发现,甲醛初始浓度较低时,BiVO4降解率优于其他,随甲醛浓度增加,催化剂降解率均呈上升趋势,TiO2-1（T-1）、TiO2-2（T-2）降解率增加显著。随环境湿度增大,降解率先上升后下降,BiVO4-1（B-1）、BiVO4-2（B-2）降解率下降的较为缓慢。同一物质当晶粒尺寸越小比表面积越大,其降解率越好。T-2比B-1有更好的稳定性。分析认为在较低甲醛浓度时,决定光催化降解率的主要因素是催化剂的表面反应速率。随着甲醛初始浓度的增加,吸附脱附成为主要限制步骤。随环境湿度增加,甲醛降解率先上升后下降,具有较小比表面积的BiVO4降解甲醛效率下降不显著。连续的工作产生甲醛分解副产物,不易堵塞具有大比表面积的T-2的活性位点,所以T-2有更好的稳定性。     

压力环境下活性污泥的耐盐驯化过程

通过逐步提高盐浓度的梯度盐度方法驯化耐盐活性污泥,采用加压-常压对比实验,探讨活性污泥耐盐驯化过程中,0.3 MPa的压力环境对有机物降解规律、污泥脱氢酶活性及胞外聚合物（EPS）含量的影响。结果表明,经耐盐驯化的活性污泥在5%的高盐度环境下仍可达到75%以上的有机物去除率;当驯化盐度达3.5%及以上,加压耐盐活性污泥有机物去除率及污泥脱氢酶活性均高于常压,其优势更为突出。耐盐驯化过程中活性污泥胞外聚合物（EPS）含量较稳定,加压系统EPS含量低于常压,这可能是加压活性污泥法可以实现原位污泥减量的重要原因之一。     

陶粒生物滤池低温处理黄河水研究

进行了利用陶粒生物滤池工艺低温生物预处理黄河微污染水的研究,结果表明,温度的降低对陶粒生物滤池去除CODMn、UV254和氨氮的影响不明显,其平均去除率分别为11%、22.2%和61.2%。水温低于5℃时出水中亚硝酸氮浓度升高。此外,低水温条件下陶粒上生物膜脱氢酶活性仍然较高。