水处理中微生物絮凝剂产生菌的选育及应用

综述了微生物絮凝剂产生菌筛选和培育方面的研究进展,介绍了微生物絮凝剂在给水和饮用水、乳化液的油水分离、污水处理等领域的应用,以及廉价培养基的探索实践。提出针对影响微生物絮凝剂产生菌生长代谢的环境条件开展深入研究,同时寻找或设计廉价培养基,降低生产成本,推动其工业化应用。     

我国防灾减灾领域学科发展及其专业设置——从学位管理制度谈起

我国高校在防灾减灾类人才培养中存在一些现实困境,如:灾害学的学科地位较低、防灾减灾类学科及专业设置不灵活、学校管理制度及其相关条例的约束等。从我国学位管理制度谈起,通过比较分析国内外高校专业设置与交叉学科发展情况,探讨我国防灾减灾领域学科发展及专业设置对防灾减灾人才培养造成的影响,并提出三点建议:一是加大我国学位管理制度的改革,确保落实高校办学自主权;二是对灾害科学的研究走向系统化、社会化,发展国内高等学校防灾减灾类专业本科教育;三是防灾减灾类专业课程设置从横向和纵向上都要体现综合和交叉的学科属性。     

Flowering pattern of biodiesel plant Jatropha in frost- and drought-prone regions of Botswana

Jatropha has gained interest as a potential biodiesel feedstock. Nevertheless, its oil production decreases significantly in frost- and drought-prone regions. In this study, we characterized the flowering pattern of Jatropha in Botswana in the 2014/2015 season. Extensive springtime pruning synchronized Jatropha regrowth in summer and effectively stimulated growth after frost damage. Flowering started in February 2015 and peaked in April and May. Wide variations in flowering frequency were observed among different Jatropha accessions. Trees flowering in February and March produced fruit in May, but most trees only flowered in April and May and did not yield fruit because of cold snaps. These observations suggested that harvesting seed before wintertime is the key to improve Jatropha production in the Botswana climate. This study highlighted the importance of inducing early flowering by developing new agricultural managements. These may include frost cover and sun shades to prevent stress-induced damage, canopy control by pruning, optimization of fertilization practice, and/or introduction of superior Jatropha varieties.     

SFBR中好氧颗粒污泥的培养及特性研究

接种自行培养的活性污泥,以模拟废水为基质,采用连续进水、间歇出水及厌氧/好氧交替的运行模式,尝试了在SFBR中进行好氧颗粒污泥的培养,并研究了好氧颗粒污泥的特性及反应器对污染物的去除效果.结果表明,通过逐步缩短沉降时间,28 d时成功培养出好氧颗粒污泥,所形成的好氧颗粒污泥呈黄色、形状不规则,且粒径较小(平均粒径0.56 mm),正常情况下的SVI保持在70 mL·g-1以下,EPS在59 d时达到最大值(以MLVSS计)373.24 mg·g-1,较培养初期增加了约2.5倍,运行后期由于颗粒出现解体,导致EPS急剧下降;反应器在运行过程中未能保持较高的污泥量,中后期MLSS始终在3 000mg·L-1以下;在63 d的运行时间里,除异常波动外,反应器对COD的去除率基本维持在90%左右,正常情况下出水COD小于100 mg·L-1,反应器对NH+4-N、TIN的去除效果波动较大,去除率分别为44.45%~94.72%及43.87%~93.13%,反应器对TP的去除率在44.50%~97.40%之间,正常情况下TP去除率可维持在60%以上;限于自动控制水平,夜间长时间的好氧饥饿期容易造成丝状菌过度生长,使得AGS在生长竞争中处于劣势,最终导致了AGS的解体.     

Effect of deforestation on fertility attributes of Mollisols in the NW of Iran

The impacts of deforestation on soil fertility indices – are still not well understood in the forest lands of Iran characterised by Mediterranean type climate. Consistent with this, 8 soil pedons and 32 soil cores were described and sampled from four different soil types of forest and adjacent cultivated soil along a Mollisols transect. The results revealed a considerable depletion in the values of soil organic carbon (by 60–88%), total N (by 67–88%), available K (by 20–45%), cation exchange capacity (by 9–21%), and the diethylene-triamine pentaacetic acid (DTPA) fraction of Fe (by 40–72%), Mn (by 10–60%), and Zn (by 49–80%) after deforestation. In contrast, soil pH (by 0.36–0.9 units), C:N ratio (by 3–84%), available P (22–139%), and DTPA Cu (by 4–55%) tended to increase due to deforestation. Cultivated soils showed a drop of 70–82% in the values of the soil productivity index than to those of the forest soil, indicating a degrading and declining effect of deforestation on soil productivity capacity. It was found that the majority of soil fertility indices were affected negatively by deforestation and more than half of the organic matter was lost to deforestation, which, in turn, could lead to deterioration in soil quality or land productivity capacity.     

Spatial identification by satellite imagery of the crop–fallow rotation cycle in northern Laos

In the mountainous regions of northern Laos, shifting cultivation, or slash-and-burn agriculture, is widely practiced. However, the crop–fallow rotation cycle is becoming shorter owing to forest conservation policies and population pressure, causing loss of productivity that deleteriously affects farmers’ livelihoods in the region. To investigate regional land use conditions, we have developed a method of identifying the crop–fallow rotation cycle from Landsat Thematic Mapper (TM) and Enhanced Thematic Mapper+ (ETM+) data. We assessed the impact of the identified cycle on plant production measured by Normalized Difference Vegetation Index (NDVI). The study site was an area in Luang Prabang Province. Using eight TM and ETM+ images acquired annually from 1995 to 2003, except for 1998, when cloud-free data were not collected, we classified land use in each year as crop or fallow by the presence of vegetation in the late dry season. Conformity with fallow age determined by field investigation was 69.1%. The cultivation frequency from 1995 to 2002 showed that 77,000 ha (17.3% of the study site) had not been used for cropping during the period, but 41,000 ha (9.2%) had been used every year. Of the study site, 129,000 ha (29.1%) was cultivated one or two times, 83,000 ha (18.7%) was three or four times, and 54,000 ha (12.2%) was five or six times. The NDVI of crops in November did not provide sufficient evidence to prove the assumption that a longer fallow period would result in better crop yields. Instead, the regeneration of fallow vegetation was evidenced by the higher NDVI values after longer fallow. More than 8 years would be needed to reach the same NDVI as forest. From the produced maps indicating fallow age and cultivation frequency, we found that areas with high potential for regeneration decreased as cultivation frequency increased. Areas near rivers were intensively used, and fallow length was accordingly short. Low-potential areas were found in the western basin of the Mekong River. This spatial information can be used to detect areas where biomass productivity is at high risk of deteriorating. Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue.     

The Dual Model for Tourism Resource Productivity Improvement

For natural resource science, resource productivity studying is an important subject. But researches on tourism resource productivity are limited. The most significant influencing factor on tourism resource productivity is the potential market scale of tourist locations, and second most important influencing factor is the resource endowment. Regional urban population is significantly correlated with region tourist numbers, being the decisive factor of region potential tour market scale. In tourism development, the dual model should be adopted: on one hand to enhance tour spot attractiveness, on the other hand to cultivate the potential market by improving urbanization level and other means. In the situation of tourism development fever spreading, the dual model for improving tourism productivity helps to avoid the "Great Leap Forward" which means that too rapid tourism construction divorces from actual market demand.     

产油微藻培养与回收的关键技术研究进展

寻找廉价而高效的替代原料是实现生物柴油产业化的关键所在.微藻以含油量高、生长周期短、环境适应能力强、生物产量高等优点,有望成为一种极具潜力的生物柴油生产原料.然而,目前尚存在微藻培养低效成本高和微藻回收效率低两大难题.综述了微藻培养与回收过程中的关键技术,并对存在的两大难题及其改进技术进行了详细的探讨.最后,总结并展望了微藻培养、回收技术未来的发展趋势.     

论园林树木栽培学(各论)的精讲教学法

园林树木栽培学是一门实践性很强的有关园林绿化领域的专业课、必修课.1995年以来,本人在园林树木栽培学各论教学中尝试重点讲解、课堂点评的教学方法,取得了较好的教学效果.     

2种反应器中好氧颗粒污泥培养的比较研究

以絮状活性污泥为接种污泥,采用人工配制的模拟生活污水,分别在气提式序批反应器(SBAR)和序批式活性污泥反应器(SBR)中成功地培养出了成熟的好氧颗粒污泥.SBAR和SBR中的好氧颗粒污泥都具有稳定的基本形态结构,其微生物主要由杆菌和球菌组成,对COD的去除率可达到93%左右.对NH+4-N的去除率可达到98%以上.SBAR中好氧颗粒污泥的粒径主要分布、污泥体积指数(SVI)、比耗氧速率(SOUR)、TN去除率和TP去除率分别为0.45～2.00 mm、19.97 mL/g、47.68 g/(kg·h)、82%和65%;而SBR中好氧颗粒污泥的粒径主要分布、SVI、SOUR、TN去除率和TP去除率分别为0.18～1.00 mm、29.12 mL/g、43.21 g/(kg·h)、58%和50%.相对而言,SBAR更有利于好氧颗粒污泥的培养和运行.