Variation of peroxidase isoenzyme and biofilm of Phanerochaete chrysosporium in continuous membrane bioreactor for Reactive Brilliant Red X3-B treatment

The influence of a Reactive Brilliant Red X-3B (RBR X-3B) dye on the peroxidase isoenzyme of Phanerochaete chrysosporium was determined, and the biofilm structure in a white rot fungal continuous membrane bioreactor (MBR) was also investigated by scanning electron microscope (SEM). The variation of peroxidase isoenzyme and the decolorization rate in the continuous MBR were evaluated. The results showed that the 100 mg/L RBR X-3B could stimulate the production of the peroxidase isoenzyme in the shaking-flask culture. In addition, two new peroxidase isoenzyme bands with relative mobility (Rf) value of 0.27 and 0.28 appeared, but the activity was lower than the blank control of 11 d. In the continuous MBR, the system worked stably during the first 60 d, the main peroxidase isoenzyme bands existed and three new bands with Rf value of 0.10, 0.27, and 0.28 appeared. Meanwhile, the biofilm grew well and the average decolorization rate could reach 90.6%. But the bands of peroxidase isoenzyme decreased rapidly at day 65, only two bands with Rf value 0.24 and 0.26 existed, and the decolorization rate decreased to 78.3%. Therefore, 5 bottles of P. chrysosporium mycelial pellet were added into the MBR, and then the activity of the peroxidase isoenzyme and the decolorization rate had a slight recovery. Finally, the decolorization rate finally decreased to 75.2%. These results contribute to a comprehensive understanding of the variation of peroxidase isoenzyme and biofilm in continuous MBR by white rot fungi.     

一体式膜生物反应器膜污染影响因素研究

试验采用聚丙烯中空纤维膜,通过正交试验考察了膜通量、抽停时间、曝气量对膜过滤压力的影响,得出适合的膜通量是减缓膜污染的决定性因素。并确定了适宜的运行条件：膜通量5L／（m2·h）,抽吸时间8min,停抽时间2min,曝气量0．6m3／h;同时考察了EPS中多糖和蛋白质对膜污染的影响,得出多糖是主要的污染物质。     

哈大高速公路交通噪声预测研究

交通噪声是环境污染的重要来源之一。随着社会和人们对环境保护意识的增强,对高速公路交通噪声的影响评价及防治越来越受到人们的重视。本文通过对哈大高速公路交通噪声的例行监测,通过对交通噪声的研究和对其影响因素进行分析,进行了一元正态线性回归分析,建立了一元正态线性模型。对哈大高速公路的噪声进行预测并提出相应的治理对策。     

Total mercury in wild fish in Guizhou reservoirs, China

The health hazard of mercury (Hg) compounds is internationally recognized, and the main pathways for methylmercury (MeHg) intake in humans are through consumption of food, especially fish. Given the large releases of Hg to the environment in China, combined with the fast development of hydropower, this issue deserves attention. Provided similar mobilization pathways of Hg in China as seen in reservoirs in North America and Europe one should expect increased Hg contamination in relation to future hydropower reservoir construction in this country. This study presents total Hg (THg) concentrations in wild fish from six Guizhou reservoirs, China. The THg concentrations in fish were generally low despite high background levels in the bedrock and depositions from local point sources. The over all mean ± SD concentration of THg was (0.066 ± 0.078) μg/g (n = 235). After adjusting for among-reservoir variation in THg, there were significant differences in THg among functional groups of the fish, assumed to re?ect trophic levels. Predicted THg- concentration ratios, retrieved from a mixed linear model, between the functional groups were 9:4:4:1 for carnivorous, omnivorous, planktivorous and herbivorous fish. This result indicated that MeHg accumulation may prevail even under circumstances with short food chains as in this Chinese water system. No fish exceeded recommended maximum THg limit for human consumption set by World Health Organization and the Standardization Administration of China (0.5 μg/g fish wet weight (ww)). Only six fish (2.5%) exceeded the maximum THg limit set by US Environmental Protection Agency (0.3 μg/g fish ww).     

水环境模拟参数随机场空间最优估计精度分析与特异值研究

本文结合克里格方差的特点,对水环境模拟参数随机场空间最优估计的精度进行了分析,结果显示估计精度受变差函数、采样点的空间配置结构等因素的影响,并结合实例探讨了影响水环境模拟参数克里格估计精度的特异值的识别与处理方法。     

建设好泛长江经济带

泛长江经济带是由长江经济带衍生出的一个新的"大流域"概念。在我国未来"三纵四横"水网布局的大背景下,泛长江经济带不局限于长江干流,同时还应覆盖由长江源头、干流、支流、人工河渠组成的生态系统的大流域,覆盖范围从原有的9省2市增加至包括青海、西藏、广西、陕西、河南、河北、山东、山西、广东、北京、天津在内的18省4市。泛长江经济带的形成是区域内各省市经济社会生态关联日益强化的客观体现。为保证泛长江经济带经济社会各方面的高效运作协调发展,建议组建"长江经济带科学协同发展领导小组"统筹协调区域内各类规划的制定及重大工程的实施,务实推进泛长江经济带建设。     

污水处理厂空气介质抗生素抗性基因的分布

考察了污水处理厂空气介质中典型的抗性基因(antibiotic resistance genes,ARGs)污染水平和浓度分布,并通过16S r RNA高通量技术对样品进行亲缘性及溯源研究。结果表明,在污水厂空气样品中8种抗生素抗性基因的检出率均超过50%,其中tet C、sul1、sul2和erm B检出率为100%。在曝气池和污泥脱水车间空气样品中8种抗性基因检出率均为100%。对其中的sul1、sul2、tet G和tet X共4种ARGs的定量分析结果表明,以上4种基因的相对浓度范围在102~105copies·ng~(-1)DNA之间,与邻近居民区空气样品抗性基因浓度处于同一水平;空气样品16S r RNA高通量测序聚类分析结果显示,居民区空气与污水厂园区内空气有较高的种群相似度,污水厂处理单元对其邻近区域的空气介质微生物组成影响较大。     

Structure and function of rhizosphere and non-rhizosphere soil microbial community respond differently to elevated ozone in field-planted wheat

To assess the responses of the soil microbial community to chronic ozone(O_3), wheat seedlings(Triticum aestivum Linn.) were planted in the field and exposed to elevated O_3(e O_3)concentration. Three treatments were employed:(1) Control treatment(CK), AOT40 = 0;(2) O_3-1, AOT40 = 1.59 ppm·h;(3) O_3-2, AOT40 = 9.17 ppm·h. Soil samples were collected for the assessment of microbial biomass C, community-level physiological profiles(CLPPs), and phospholipid fatty acids(PLFAs). EO_3 concentration significantly reduced soil microbial carbon and changed microbial CLPPs in rhizosphere soil, but not in non-rhizosphere soil.The results of the PLFAs showed that e O_3 concentrations had significant effects on soil community structure in both rhizosphere and non-rhizosphere soils. The relative abundances of fungal and actinomycetous indicator PLFAs decreased in both rhizosphere and non-rhizosphere soils, while those of bacterial PLFAs increased. Thus the results proved that e O_3 concentration significantly changed the soil microbial community function and composition, which would influence the soil nutrient supply and carbon dynamics under O_3 exposure.