微囊化生物流化床处理邻二氯苯废水

采用海藻酸钠—壳聚糖—活性炭(SA-CA-PAC)生物微胶囊包埋优势降解菌用于生物流化床处理邻二氯苯废水。比较了微囊化菌和悬浮菌对废水的降解效果,同时考察了初始浓度、接种量、pH值、温度和曝气量对降解率的影响。结果表明,微囊化菌比悬浮菌拥有更适宜的生长环境,具有更好的pH稳定性和热稳定性。微囊化菌的降解效果优于悬浮菌,处理150 mg/L的邻二氯苯废水的最佳接种量为10%,最适pH为7.5,最适温度为30℃。     

添加VT菌剂和有机物料腐熟齐对堆肥的影响

通过在高温好氧堆肥中分别添加VT菌剂和有机物料腐熟剂，研究接种3％o的VT菌剂和有机物料腐熟剂促进堆肥的作用效果。结果表明，接种VT菌剂的处理与空白和接种有机物料腐熟剂的处理相比，堆肥初期升温更快；高温期更长；堆肥结束时，C／N降低的多，NO3-N增加的多，NH4-N挥发的少，接种VT菌剂和VT有机物料腐熟剂都可促进有机质的充分降解，缩短堆肥时间，加快堆肥腐熟，提高堆肥肥力。     

低浓度LAS对活性污泥性质和去除污染物行为的影响

采用SBR处理模拟废水,考察了不同浓度阴离子表面活性剂——烷基苯磺酸钠（LAS）对反应器活性污泥的影响。实验结果表明,低浓度表面活性剂LAS的投加,有利于提高SBR中活性污泥对COD和氨氮处理效率,并且活性污泥的沉降性以及微生物活性也随着LAS投加浓度的升高而升高。但是,当LAS的投加浓度过高时（1 mg/L）,污泥表面产生起泡、乳化和微粒悬浮等现象,使大量固体陷入漂浮泡沫层,降低曝气池的充氧效率,最终导致污泥解体,沉降性变差,活性下降。     

Interactions of Sulfur Dioxide with Insoluble Suspended Particulate Matter

A laboratory study was conducted of the heterogeneous catalysis of sulfur dioxide at ppm concentrations in air by insoluble particles of CaCO₂, V₂O₅, Fe₂0₃, flyash from a coal-burning power plant, MnCO₂, activated carbon, and suspended particulate matter from urban air. The investigalion was performed by utilizing a new technique for aerosol stabilization which consists of depositing the aerosol on Teflon beads in a fluidized bed. The Teflon beads with deposited aerosol particles were then packed into a flow reactor. Progress of the chemical reaction of SO₂ with deposited particles was continuously monitored by determining the SO₂ concentrations in the reactor effluent with a microcoulometer.

In this investigation, CaCOg, V₂O₅, and flyash were essentially inert to SO₂ at room temperature. Fe₂O₃, activated carbon, MnO₂, and suspended particulate matter from urban air sorbed SO₂ from air streams with up to 14.4 ppm SO₂ in air. Evidence is presented which suggests that a substantial part of the sorbed SO₂ was physically adsorbed.

Bioassay procedures which utilize pulmonary flow resistance changes in guinea pigs to monitor response to inhaled SO₂-aerosol mixtures in air have indicated the weak or non-potentiating capacity of insoluble aerosols as contrasted to soluble aerosols. Potentiating response of an aerosol appears to be strongly associated with reaction of SO₂ in a water droplet containing aerosol ions and not with physically adsorbed SO₂ on an insoluble aerosol.     

Which forcing factors fit? Using ecosystem models to investigate the relative influence of fishing and changes in primary productivity on the dynamics of marine ecosystems

Fishing mortality and primary production (or proxy for) were used to drive the dynamics of fish assemblages in 9 trophodynamic models of contrasting marine ecosystems. Historical trends in abundance were reconstructed by fitting model predictions to observations from stock assessments and fisheries independent survey data. The model fitting exercise derives values for otherwise unknown parameters that specify the relative strength of trophic interactions and, in some instances, a time series anomaly for changes in primary production. We measured how much better or worse were model predictions when bottom-up forcing by primary production were added to top-down forcing by fishing. Searching for cross system patterns, the relative contribution of fishing and changes in primary production, mediated through trophic interactions, are evaluated for the ecosystems as a whole and for selected similar species in different ecosystems. The analysis provides a simple qualitative way to explain which forcing factors have most influence on modeled dynamics. Both fishing and primary production forcing were required to obtain the best model fits to data. Fishing effects more strongly influenced 6 of 9 of the ecosystems, but primary production was more often found to be the main factor influencing the selected pelagic and demersal fish stock trends. Examination of sensitivity to ecological and model parameters suggests that the results are the product of complex food-web interactions rather than simple deterministic responses of the models.     

Impacts of Dung Combustion on the Carbon Cycle of Alpine Grassland of the North Tibetan Plateau

Alpine grassland of Tibet is a frangible ecosystem in terms of carbon (C) emission. Yak dung is an important resident energy with about 80 % of yak dung combusted for energy in the north Tibetan plateau. This paper investigated the impact of dung combustion on the C cycle of the alpine grassland ecosystem in north Tibet, China. During the growing season of 2011, from a field survey and household questionnaires, the main impacts of dung collection for fuel on the C cycle of the ecosystem were identified. (1) The C sequestration and storage capacity, including the dung-derived C stored in soil and C captured by vegetation, decreased. The net primary production decreased remarkably because of the reduction of dung returned to soil. (2) In a given period, more C was emitted to the atmosphere in the dung combustion situation than that in the dung returned to soil situation. (3) The energy grazing alpine meadow ecosystem changed into a net C source, and the net biome production of the ecosystem dropped to ?15.18 g C/m² year in the dung combustion situation, 42.95 g C/m² year less than that in the dung returned situation. To reduce the CO₂ emission derived from dung use, the proportion of dung combustion should be reduced and alternative renewable energy such as solar, wind, or hydro energy should be advocated, which is suitable for, and accessible to, the north Tibetan plateau.     

溶藻放线菌改性制剂对铜绿微囊藻的控藻能力研究

采用喷雾干燥法制备了一种溶藻放线菌粉剂,此粉剂按1∶10 000的质量比投加4 d后对铜绿微囊藻的溶藻效率可达90%,该粉剂经过壳聚糖改性处理后,在1∶20 000的质量投加比下,0.5 h即可絮凝去除90%的藻细胞,4 d后的溶藻效率仍可达80%。由于既能快速絮凝除藻,又能长效溶藻,使得改性溶藻放线菌粉剂具有更为广阔的应用前景。     

冶金工业固体废物钢渣的综合利用

首先概述了钢渣的来源、化学组成及加工方法等;其次对钢渣的国内外综合利用途径进行了综述,分别介绍了利用磁选工艺回收废钢铁,作为冶金原料、建筑材料,以及在农业和水处理方面的应用特点和应用实例,并指出,在农业和水处理方面,钢渣具有广泛的应用价值和显著的社会经济效益;最后对钢渣综合利用的前景进行了展望,提出了加快钢渣资源化利用的建议。     

固定化啤酒废酵母对Cr(Ⅵ)的吸附

用2%海藻酸钠与1%明胶混合作为包埋剂固定啤酒废酵母，研究固定化啤酒废酵母对Cr(Ⅵ) 的吸附特性。结果表明，固定化啤酒废酵母吸附Cr(Ⅵ) 受吸附时间、起始pH 、固定化菌体浓度、Cr(Ⅵ) 起始浓度及共存离子等因素的影响。确定固定化啤酒废酵母对Cr(Ⅵ) 最佳吸附条件为：pH 2，Cr(Ⅵ) 起始浓度100 mg/L ，固定化菌体浓度2 g/L，吸附90 min 。此条件下Cr(Ⅵ) 的吸附率可达96.8%。Pd²⁺等并存离子可抑制固定化啤酒废酵母对Cr(Ⅵ) 的吸附。用1 mol/L盐酸洗脱固定化啤酒废酵母所吸附的Cr(Ⅵ) 3 h，解吸率为93.6%。