炼油污水厂生物强化处理中试研究

为考察生物强化技术对污水系统污染物去除能力和稳定性的改善情况，验证生物强化技术在炼油废水处理中的应用效果，开展了生物强化技术处理炼油废水的中试研究。结果表明，经过生物强化培养后，COD去除率由原来的平均78．23％-78．75％提升至86．48％-89．09％，氨氮去除率由原来的平均58．40％～90．96％提升至95．51％-96．96％，污泥沉降性大幅改善，出水悬浮物明显减少。     

Geographic clines and stepping-stone patterns detected along the East Pacific Rise in the vetigastropod Lepetodrilus elevatus reflect species crypticism

Three different molecular markers (i.e. seven allozyme loci, two nuclear gene loci and, mtCOI DNA sequences) were used to assess the genetic structure of the vent gastropod Lepetodrilus elevatus collected from three vent fields along the East Pacific Rise (13°N, 9°50′N and 17°S). While allozymes and nuclear loci suggested a strong stepping-stone pattern, a multivariate analysis performed on allozymic frequencies showed the presence of two distinct evolutionary lineages: the first situated in the north from 13°N to 9°50′N and the second in the south from 9°50′N to 17°S. The analysis of mitochondrial DNA sequences confirmed the separation of L. elevatus into two distinct clades with a divergence of 6.5%, which is consistent with the interspecific level of sequence variation in other vent species. A divergence time of 6–14 Mya was estimated between the two clades from previous clock calibrations. Our results suggest that these taxa followed an allopatric speciation between the northern and southern parts of the EPR with a recent demographic expansion of the southern clade to the north and a subsequent secondary contact (clade hybridisation). This speciation was probably reinforced by a habitat specialisation of the two cryptic species because the southern clade was mainly found associated with mussel-dominated communities and the northern clade with tubeworm-dominated communities. However, the analysis of shell morphology failed to separate the two cryptic species based on this sole criterion although they differed from Lepetodrilus elevatus galriftensis (Galapagos population) by a higher shell elevation. Within each clade, genetic differentiation was not related to the distance across populations and could be within vent field as important as between fields. While both clades appear to be in expansion since their speciation, significant excesses in heterozygotes suggest a very recent and local bottleneck at 17°S, probably due to massive site extinction in this region.     

Regimes of human and climate impacts on coastal changes in Vietnam

Vietnam is a tropical to subtropical country located on the eastern Asian coast where the Red (Song Hong) and Mekong rivers discharge into the sea. The catchments of these two transboundary rivers cover parts of six countries, and their water and sediment discharges greatly influence the coastal seas of Vietnam. The impact of human activities include changes in the supply and distribution of water, sediments, and nutrients; changes in the relationships and balance among dynamically interacting factors and processes; and changes in the quality of the coastal and marine environments due to the increased use and accumulation of pollutants and the loss of habitats. These impacts have resulted in increasing unpredictability and severity of coastal problems such as floods, erosion, sedimentation, and saltwater intrusion; environmental pollution; and the degradation of ecosystems, with accompanying decrease in biodiversity and fishery productivity.     

振动与冲击试验中单自由度线性系统损坏可能性的比较

比较了单自由度线性机械系统在稳态振动，随机振，运输试验以及冲击试验中响应的大小。     

Water-induced erosion potentiality and vulnerability assessment in Kangsabati river basin,eastern India

Environment, Development and Sustainability - The large-scale water-induced erosion is one of the most determining elements on land degradation in subtropical monsoon-dominated region. From this...     

Sustainability assessment of coastal ecosystems: DPSIR analysis for beaches at the Northeast Coast of Vietnam

Environment, Development and Sustainability - The Northeastern coastal zone of Vietnam possesses high biodiversity and rich ecosystems like coral reefs, seagrasses, beaches and mangroves. It also...     

加碱混凝沉淀法去除蓝皮制革废水中Cr^3＋及COD的研究

取自扬州某外资皮革厂的蓝皮制革废水含有大量的Cr^3＋和COD。通过对该废水加各种碱剂调节其pH值至8．3～8．5，均可将Cr^3＋去除90％以上，且对COD也有一定的去除效果。再对该废水加碱的同时试采用几种混凝剂进行混凝，Cr^3＋和COD的去除率都得到提高。研究表明：通过加碱混凝能取得更好的去除效果，PAC／PAM是最佳混凝剂，最佳投药量为0．4g／L，Cr^3＋可降到国家标准以下。