BOD5测定的简捷方法研究

目前国内外普遍规定20±1℃培养5天,分别测定样品培养前后的溶解氧(简称DO),二者之差即为BOD5值.对同一水样,只测出培养前的任一稀释倍数水样的DO值,通过计算便可准确得出其它稀释倍数水样的D0值.通过对不同浓度下BOD5实测值与计算值进行比较,计算出相对误差进行分析,结果都达到了水质监测实验室质量控制指标-准确度允许差.因此,这种计算方法是切实可行.     

矿区生活污水厌氧处理工艺中试研究

通过分析高效厌氧反应器（UASB）处理矿区生活污水的中试，为工业化应用获得了可靠的基础参数。     

络合萃取法处理5-氯水杨酸生产废水的研究与实践

采用络合萃取法处理5-氯水杨酸生产废水,研究了萃取过程中PH、络合剂、稀释剂等对废水革取效果的影响。通过比较,确定以EPT-1为络合剂。试验表明,pH<1.5,按废水:络合剂:稀释剂-100:30:70的比例投加,可取得较好效果。萃取剂连续使用15次,废水的CODCr去除率并无显著下降。多次萃取后萃取剂经氢氧化钠溶液反萃取再生,即可回收萃取剂。     

固定化微生物强化处理对甲苯胺模拟废水的研究

采用新型固定化载体大孔吸附树脂X-5固定化微生物强化SBR处理对甲苯胺模拟废水，与对照组相比，通过投加大孔吸附树脂X-5固定化微生物可以有效提高反应器的处理效率。在进水TOC浓度为434．8mg／L，对甲苯胺浓度为326．9mg／L的条件下，强化组可在100min左右将TOC和对甲苯胺基本去除完全，去除率在99％以上。对照组则需要300min才能达到相近的去除效果。强化组对氨氮同样具有较好的硝化效果，出水氨氮浓度在10mg／L以下。     

Predicting tree species presence and basal area in Utah: A comparison of stochastic gradient boosting,generalized additive models,and tree-based methods

Many efforts are underway to produce broad-scale forest attribute maps by modelling forest class and structure variables collected in forest inventories as functions of satellite-based and biophysical information. Typically, variants of classification and regression trees implemented in Rulequest's^© See5 and Cubist (for binary and continuous responses, respectively) are the tools of choice in many of these applications. These tools are widely used in large remote sensing applications, but are not easily interpretable, do not have ties with survey estimation methods, and use proprietary unpublished algorithms. Consequently, three alternative modelling techniques were compared for mapping presence and basal area of 13 species located in the mountain ranges of Utah, USA. The modelling techniques compared included the widely used See5/Cubist, generalized additive models (GAMs), and stochastic gradient boosting (SGB). Model performance was evaluated using independent test data sets. Evaluation criteria for mapping species presence included specificity, sensitivity, Kappa, and area under the curve (AUC). Evaluation criteria for the continuous basal area variables included correlation and relative mean squared error. For predicting species presence (setting thresholds to maximize Kappa), SGB had higher values for the majority of the species for specificity and Kappa, while GAMs had higher values for the majority of the species for sensitivity. In evaluating resultant AUC values, GAM and/or SGB models had significantly better results than the See5 models where significant differences could be detected between models. For nine out of 13 species, basal area prediction results for all modelling techniques were poor (correlations less than 0.5 and relative mean squared errors greater than 0.8), but SGB provided the most stable predictions in these instances. SGB and Cubist performed equally well for modelling basal area for three species with moderate prediction success, while all three modelling tools produced comparably good predictions (correlation of 0.68 and relative mean squared error of 0.56) for one species.     

Photocatalytic properties of hierarchical CuO nanosheets synthesized by a solution phase method

CuO nanomaterials were synthesized by a simple solution phase method using cetyltrimethylammonium bromide(CTAB) as a surfactant and their photocatalytic property was determined towards the visible-light assisted degradation of Reactive Black-5 dye. A detailed mechanism for the formation of CuO nanostructures has been proposed.The effect of various experimental parameters such as catalyst amount, dye concentration,p H and oxidizing agent on the dye degradation efficiency was studied. About 87% dye was degraded at p H 2 in the presence of CuO nanosheets under visible light. The enhanced photocatalytic activity of CuO nanosheets can be ascribed to good crystallinity, grain size,surface morphology and a strong absorption in the visible region. CuO is found to be a promising catalyst for industrial waste water treatment.     

GCM预测情景下中国21世纪干旱演变趋势分析

未来气候变化情景下,我国干旱事件发生的趋势具有诸多不确定性。基于国际耦合模式比较计划第五阶段（CMIP5）中6个GCM模式的未来气候变化情景数据,采用帕尔默干旱指数（Palmer Drought Severity Index,PDSI）,评估了21世纪RCP （Representative Concentration Pathway） 4.5和RCP 8.5情景下我国干旱事件发生的时空变化特征。结果表明：21世纪中后期,由于气候显著变暖而降水变化不稳定,我国将面临广泛的干旱化趋势,其中干旱频次、持续时间和强度都呈显著上升趋势。相对于基准期,干旱事件的空间格局也将发生变化,其中北方地区干旱事件历时和频次明显增加,而南方严重干旱事件的强度加剧。尽管未来气候变化情景下降水小幅增加,但仍不能扭转因增温所导致的区域干旱化趋势。因此,在制订和实施应对气候变化的旱灾预防、减缓及适应性方案和措施时,需要考虑气温和降水变化时空不匹配等因素的影响,从水热两方面调控干旱的不利影响。     

Particles and porous tablets based on Fe0/ZSM-5 composites prepared by ball-milling for heavy metals removal: Dissolved Fe2 +, pH, and mechanism

Novel, low-cost Fe~0/ZSM-5-based particles and porous tablets were prepared by a ballmilling method and used for the removal of Pb~(2+) in solution. Solid-phase characterization by scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy(SEMEDS) and transmission electron microscopy(TEM) revealed that the Fe0 microparticles were evenly loaded and tightly immobilized on the surface of ZSM-5 because of the extrusion/welding impact during ball-milling. For different Pb~(2+) concentrations, batch experiments indicated that the removal of Pb~(2+) increased with the decline of dissolved Fe2+and p H value in the solution for particles; opposite results were obtained for the tablets. The differences in the contact between both materials and Pb~(2+) were the main factor controlling Pb~(2+) removal in the solution. Investigation into the effect of initial p H value revealed that high p H reduced the number of electrons released from Fe corrosion. Consequently, low levels of removed Pb~(2+) and dissolved Fe~(2+) were synchronously observed. Also, simulated electroplating wastewater was treated using the prepared particles and porous tablets,and the removal order of Pb~(2+) Cr~(6+) Cu~(2+)≈ Cd~(2+) was observed. The Fe~0/ZSM-5 particles and tablets prepared through ball-milling show potential as materials for treatment of Pb~(2+) and other toxic metals.     

节杆菌P-1和红球菌J-5降解PVA特性的比较研究

对节杆菌P-1和红球菌J-5降解聚乙烯醇(PVA)的特性进行了比较研究.结果表明,P-1菌在PVA浓度小于1000mgL-1时,PVA降解效率均达到80%以上;J-5菌在PVA浓度为2000mgL-1时,PVA降解效率达到70%.用生产废水进行试验,P-1菌对低浓度PVA废水的处理效率比J-5菌高10%左右;P-1菌受温度的影响小于J-5菌;P-1菌的废水处理效果比J-5菌稳定;分段使用J-5菌与P-1菌处理高浓度的PVA废水具有很好的处理效果,出水能达到国家排放标准.图7表1参9     

青霉菌对活性艳蓝 KN-R的吸附作用

研究了青霉菌(Penicillium X5)对活性艳蓝KN—R的吸附作用．通过对培养液的波谱分析和宏观现象的观察，结果表明，在72h内，脱色是由吸附引起的．当染料的浓度为100mg/L时，活菌体对染料的吸附率可达88．66％．本实验还研究了对实际应用和吸附过程有影响的几个因素，包括葡萄糖、NaCl、温度和pH.结果表明：葡萄糖浓度在0-20g／L时，随着葡萄糖浓度的增加，菌体的干重相应增加，说明对活性艳蓝KN—R的吸附具有促进作用，但浓度在10-20g／L时，吸附作用不显著；而随着NaCl浓度(0-2％)的增加，吸附率却显著降低．最佳脱色温度为25℃，pH为4．0．活菌体与死菌体的生物吸附均符合Langmuir方程，活菌体比死菌体具有更好的吸附性能．吸附在菌丝体上的染料可以用甲酵进行洗脱，菌丝球在下次使用前用蒸馏水冲洗至pH中性，此菌丝球可重复使用3次．固8表2参11