高效堆肥菌种的筛选及在城市污泥堆肥上的应用

分离筛选出了4株猪粪堆肥菌种,初步的分类鉴定表明它们均属于芽孢杆菌属.利用这些菌种制成混合菌剂,并进行城市污泥堆肥对比试验,结果显示,接菌处理在各项堆肥指标上明显优于未接菌的空白处理,自制菌与酵素菌在堆肥过程中具有非常相似的发酵能力,均能加快堆肥的升温速度,提高堆肥的最高温度,加快物料含水率的下降.说明自制菌不但可以应用于猪粪的堆肥发酵,在城市污泥高温堆肥方面也有很好的应用潜力.     

Level and distribution of DDT in surface soils from Tianjin, China

One hundred and eighty eight surface soil samples were collected from the Tianjin area to study the contamination of DDT and its metabolites. Measurements were taken for p,p'-DDE, p,p'-DDD, p,p'-DDT, o,p'-DDE, o,p'-DDD and o,p'-DDT for all samples. The results indicated that p,p'-DDT and p,p'-DDE were the predominant contaminant compounds in the surface soil samples, with mean concentrations of 27.5 and 18.8 ng g(-1) respectively. No significant differences in DDT concentrations were found between the soils from wastewater treated irrigated areas and other areas, suggesting that wastewater irrigation is not an important source of DDT in the area. However, the spatial distribution of soil DDTs levels in the area did correlate well with early direct application rates of pesticides. In addition, both pH level and organic carbon content are also known factors affecting the level of DDT and its metabolites. Although it was assumed that the use of these chemicals was banned in the early 1980s, the current concentration levels appear to be too high to be mere residuals after 20 years degradation.     

包埋固定化微生物法处理含油废水研究

本研究通过包埋固定化微生物法固定除油(Y1#菌),用于处理含油废水,并以水体中乳化油去除率为指标考察了影响乳化油降解的各种因素.选用聚乙烯醇(PVA)-海藻酸钠(SA)复配作为包埋固定化载体材料,制备成固定化微生物小球(IMB),通过实验优化了IMB制备的工艺条件.连续批次除油实验结果表明,在25～40℃,固液比1∶10,HRT为6 h的条件下,进水油含量在20～50 mg/L,乳化油去除率可达85%～90%,出水油含量低于5 mg/L.     

新型烟气冷凝节能与脱硫装置研究

烟气冷凝节能与脱硫装置是适用于燃油燃气锅炉的新装置。本文介绍了该装置节能及脱硫的基本原理,利用81.4KW天然气锅炉实验系统对装置的传热和脱硫特性进行了研究。实验表明,该装置提高锅炉效率为3％-8％,脱硫效率为20％-40％。     

垃圾分选设备及垃圾处理技术展望

我国是人口大国 ,随着人民生活水平的不断提高 ,现有的垃圾处理技术已逐渐不能适应产量日益增长与成分不断复杂化的垃圾处理的需要 ,垃圾处理急需一场革命性的变化 ,必须摆脱现有城市垃圾处理三大方法面临的技术上难以避免的弊端和“阴影”。也就是说 ,垃圾处理应该从垃圾分选设备技术整体创新入手 ,引入一整套的垃圾机械处理联合装置及各种新型的联合处理方法 ,使垃圾处理成本大大降低 ,从而产生一次历史转折性的突破 ,带动和实现垃圾处理的产业化。为了达到这一目标 ,对垃圾处理需要重点解决的技术难关进行了探讨与展望     

大气颗粒物上多环芳烃的识别和源解析的进展

本文对当前大气颗粒物上ＰＡＨｓ的识别和源解析的定量及定性和半定量的方法进行了综述，定性及半定量方法简便易行，但误差大；化学质量平衡法结果较准确具体，但ＰＡＨｓ会发生化学反应而降解，并且没有各种燃烧源较完整的ＰＡＨｓ成份谱，这已成为ＣＭＢ广泛推行的障碍；多元统计方法不考虑ＰＡＨｓ的降解，但要求数据量大，国内外的科学工作者用不同的方法和手段，使ＰＡＨｓ来源的识别和源解析工作有了一定进展。     

城市室内环境多环芳烃污染与源的相关性

本实验选择了天津市４类典型室内环境和２处室外对照点，共１９个采样点。现场采样测定了１０种ＰＡＨｓ组成含量。结果显示，室内燃煤和室内吸烟是室内环境中多环芳烃排放的主要污染源。同作为对照的室外大气中多环芳烃组成和含量进行了对比，研究了室内环境不同污染源排放多环芳烃组成和含量的特征性。提出了室内燃煤污染同燃煤型室外大气源排放多环芳烃具有相似组成含量特征，而室内烟草烟雾污染源的多环芳烃组成含量特征则与室外     

Distribution normality of pH and H<Superscript>+</Superscript> activity in soil

Soil pH, a log-transformed form of hydrogen ion (H⁺) activity, is often used for various statistics. However whether soil pH meets the requirement of distribution normality for statistical analyses is unknown. We studied the statistical suitability of both soil pH and H⁺ activity by examining their distribution normalities. Results show that the variability of H⁺ activity is higher and its distribution is skewer, which is significantly different from the normal and soil pH, regardless of soil conditions and analytical methods. Here we demonstrate that soil pH is more appropriate than the H⁺ activity for performing statistical analysis in terms of distribution normality.     

邻苯二甲酸二丁酯对大型蚤(Daphnia magna)的毒性作用研究

本研究选用大型蚤(Daphnia magna)作为实验生物,研究了邻苯二甲酸二丁酯(DBP)对其急性毒性作用和慢性毒性作用,同时还研究了环境因素(温度、硬度、腐殖酸)对DBP24h-EC(50)的影响.结果表明DBP对大型蚤的24h-EC_(50)为10.35mg·1~(-1),温度、硬度和腐殖酸对DBP24h-EC_(50)均有一定影响.DBP对大型蚤的捕食行为产生抑制,EC_(50)在 6—7mg·1~(-1)之间.慢性毒性实验结果表明DBP对大型蚤的生长繁殖产生一定影响,低浓度DBP对大型蚤生长繁殖有一定的刺激作用,高浓度DBP对大型蚤生长繁殖存在抑制作用,BDP的最大允许安全浓度为1—2mg·1~(-1).     

Effects of Population Size, Mating System, and Evolutionary Origin on Genetic Diversity in Spiranthes sinensis and S. hongkongensis

Hong Kong once supported more than 109 species of wild orchids, of which approximately 30% were endemic. Most of the local wild orchids have now become rare or endangered. I conducted a comparative study of genetic diversity in two closely related terrestrial orchids, an allotetraploid, Spiranthes hongkongensis , and its diploid progenitor, S. sinensis , to assess the effects of the population bottleneck associated with the origin of the polyploid and to investigate the relationships between number of breeding individuals, mating system, and level of isozyme variation in their populations. Nearly complete genetic uniformity was observed both within and among populations of S. hongkongensis . In contrast, S. sinensis had high levels of genetic variation for all of the genetic parameters examined. Regression analysis of population size and several components of genetic diversity in S. sinensis revealed that, among various measures of within-population variation, the proportion of polymorphic loci ( P ) and average number of alleles per locus ( A ) or per polymorphic locus ( A _p ) were the most sensitive to population size ( R ² = 0.942, p = 0.001; R ² = 0.932, p = 0.002; and R ² = 0.923, p = 0.002 respectively). The highly negative correlation ( r = −0.999, p < 0.01) between population size and the mean frequency of private alleles in pairwise population comparisons, p (1), indicated that population size may also be used to predict the extent of population differentiation caused by random genetic drift. Conservation of genetic diversity in S. sinensis could be maximized by protecting several of both large and small populations, whereas fewer populations may be needed to achieve this goal for S. hongkongensis.