高梯度磁分离技术在水处理中的应用及发展

高梯度磁分离技术是一种新型的水处理技术,目前已经得到了大量应用,具有广阔的应用前景。本文介绍了它的基本原理,综述了该技术在水处理中的应用现状,并做出了展望。     

低温阶段程序升温法对煤氧化过程影响的研究

基于温控方式对煤氧化指标测试的重要性,采用自主研制的煤氧化模拟试验系统,通过与恒温测试法对比煤氧化升温过程中CO的生成量,研究低温阶段程序升温法对煤氧化过程的影响。结果表明:程序升温法能较好地表现出煤的氧化能力,但程序升温会造成煤样罐中温度场分布不均匀,温度梯度逐渐增大,煤体氧化程度不相同。低温条件下,程序升温法对煤氧化过程的影响总体上还比较小,且程序升温法采用程序控制温升,升温连续性好,操作简单,是一种可靠的温控方式,可以替代恒温测试法进行测试,有很好的应用价值。     

煤矿风险预控连续统一体理论研究

为了使煤矿被动式的安全管理模式真正转变为主动式预控管理模式,从而打造本质安全型矿井,借鉴领导方式连续统一体理论,提出煤矿风险预控连续统一体理论,建立煤矿风险梯度控制框架。将煤矿风险预控对象划分为4种类型,即稳定的安全系统、失稳的安全系统、事故紧急状态和事故,针对不同预控对象所实施的安全管理模式就构成风险预控的"连续统一体"。对煤矿风险应实施梯度控制,控制方案从高梯度到低梯度依次为预防控制、校正控制、应急控制和事故控制。研究表明:只有做好每一个风险阶段的安全管理工作,才能实现煤矿本质安全的目的。     

河口盐度梯度下短叶茳芏沼泽湿地土壤间隙水溶解性甲烷时空特征

以闽江口短叶茳芏沼泽湿地为研究对象,沿半咸水至淡水的盐度梯度采集土壤样品,测定分析样品间隙水溶解性CH4浓度及其主要理化指标,探讨了河口沼泽湿地间隙水溶解性CH4浓度的时空特征及其影响因子.结果表明:1夏季鳝鱼滩、蝙蝠洲和下洋洲湿地间隙水CH4浓度均值分别为331.18、299.94和638.58μmol·L-1,冬季均值分别为9.04、266.67和322.68μmol·L-1,呈现夏季显著高于冬季的时间动态特征(P0.05);2沿半咸水至淡水的盐度梯度,间隙水溶解性CH4浓度呈现递增的空间分布特征;3土壤间隙水CH4浓度与土温、DOC呈显著正相关关系,与土壤p H、盐分和间隙水SO2-4、Cl-浓度呈显著(P0.05)或极显著负相关关系(P0.01),河口盐度梯度下短叶茳芏沼泽湿地间隙水CH4浓度时空特征是土壤理化性质和潮汐等综合作用的结果.     

Bioaugmentation with a pyridine-degrading bacterium in a membrane bioreactor treating pharmaceutical wastewater

The bacterial strain Paracoccus denitrificans W12, which could utilize pyridine as its sole source of carbon and nitrogen, was added into a membrane bioreactor （MBR） to enhance the treatment of a pharmaceutical wastewater. The treatment efliciencies investigated showed that the removal of chemical oxygen demand, total nitrogen, and total phosphorus were similar between bioaugmented and non-bioaugmented MBRs, however, significant removal of pyridine was obtained in the bioaugmented reactor. When the hydraulic retention time was 60 hr and the influent concentration of pyridine was 250-500 mg/L, the mean effluent concentration of pyridine without adding W12 was 57.2 mg/L, while the pyridine was degraded to an average of 10.2 mg/L with addition of W12. The bacterial community structure of activated sludge during the bioaugmented treatment was analyzed using polymerase chain reaction-denaturing gradient gel electrophoresis （PCR-DGGE）. The results showed that the W12 inoculum reversed the decline of microbial community diversity, however, the similarity between bacterial community structure of the original sludge and that of the sludge after bioaugmentation decreased steadily during the wastewater treatment. Sequencing of the DNA recovered from DGGE gel indicated that sp., Sphingobium sp., Comamonas sp., and Hyphomicrobium sp. were the dominant organisms in time sequence in the bacterial community in the bioaugmented MBR. This implied that the bioaugmentation was affected by the adjustment of whole bacterial community structure in the inhospitable environment, rather than being due solely to the degradation performance of the bacterium added.     

梯度洗脱离子色谱法测定降水中六种阴离子及离子平衡的讨论

研究了用KOH淋洗液自动发生一离子色谱法测定降水中无机阴离子F-、C1-、SO42-、NO3-和有机酸根甲酸根、乙酸根的梯度淋洗条件,该方法17rain内可将降水中的6个阴离子全部分离,回归曲线线性良好,检出限在O．011～0．057mg／L,相对标准偏差为0．96％～2．4％,加标回收率在94．4％～104％,是一种较理想的测定降水中阴离子的方法。其中甲酸和乙酸的测定作为常规降水检测的一个补充,可通过离子平衡检验来确定降水中是否加测甲酸和乙酸。     

高频间歇梯度曝气启动短程硝化反硝化除磷颗粒污泥

反硝化除磷与厌氧氨氧化耦合可进一步降低脱氮除磷所需的碳源,而稳定获取NO₂^--N是两工艺独立、联合运行的关键.因此,以低C/N生活污水为研究对象,接种絮状污泥及少量长期贮存的好氧颗粒污泥,采用两段梯度曝气,并控制停曝时间（3min：3min）,即以高频间歇梯度曝气模式,经60d的富集培养,将其诱导成具有短程硝化反硝化除磷功能的颗粒污泥,并分析了此过程中系统脱氮除磷性能变化.结果表明,稳定时期内,颗粒污泥平均粒径达841μm,SVI为31.23ml/g,颗粒结构致密,沉降性能良好.出水NO₃^--N小于0.1mg/L,TP<0.7mg/L,NO₂^--N>15mg/L,实现了P的高效去除和NO₃^--N的积累,并可为后续耦合Anammox提供稳定NO₂^--N基质.批次实验结果表明,颗粒中可利用NO₂^--N为电子受体的DPAOs占达57.63%,其富集提高了系统除磷能力.高频梯度间歇曝气可实现AOB与DPAOs的高度耦合,但仅以间歇曝气难以实现NOB的抑制,后通过在"氨谷点"前段,加入梯度曝气优化实际限氧曝气点,可强化对NOB的抑制,从而实现良好的亚硝酸盐积累.     

实验室太阳辐射试验中温度测量的分析

按GJB 150.7-1986中稳态长期光化学效应的试验要求,对线缆样件进行了实验室太阳辐射试验。温度测量结果显示,样件的附加温升显著,且内部存在热梯度。     

Distribution of plants differing in attitude toward thermal conditions in communities of the timberline ecotone on Mount Iremel’, the Southern Urals

Specific features in the distribution of plant species differing in their attitude toward thermal conditions have been studied in communities of the present-day timberline ecotone on Mount Iremel’ in the Southern Urals. It has been shown that the distribution of such species is characterized by significant spatial nonuniformity. Elevation above sea level, local conditions in habitats located at the same altitudinal level, and specific features of mountain slopes account for 13–84, 5–30, and 0.4–14% of the total variance of test parameters, respectively. The abundance of plants changes nonlinearly along the altitudinal gradient, whereas changes in the species diversity of different plant groups have an almost linear pattern. Marked differences between plant communities with respect to the proportions of species differently responding to changes in thermal conditions have been revealed on all slopes in the upper part of the timberline ecotone, upon transition from the slopes proper to the plateau-like areas of intermontane depressions.