活性污泥和生物膜复合模型的建立与模拟

针对近年来出现的城市污水处理厂活性污泥和生物膜复合工艺,首先建立了能同时描述碳氧化、脱氮和除磷的修正ASM1（Activated Sludge Model No.1）,以及与ASM1中微生物生长过程速率方程结构形式相同、物理意义明确的生物膜模型。然后将该生物膜模型与修正的ASM1相结合,形成了活性污泥和生物膜复合模型,利用VB6.0编写了相应的模拟软件。以西安市第五污水处理厂复合工艺为对象,对其碳、氮和磷的去除进行模拟,结果表明该模型可以较好地反映出水各污染指标的变化规律。通过对进水流量、填料区的位置及填料区填料的投加率进行模拟,为填料区的优化和系统运行提出了建议。     

中型污水处理厂中药物和个人护理品的分布与去除

为了解15种药物及个人护理用品(PPCPs)在中小型污水处理厂中的分布及其去除效果,采用液相色谱-串联质谱(LC-MS/MS)技术对3座A2/O工艺的污水处理厂水样进行分析研究。结果显示,除普萘洛尔、吉非罗平和吲哚美辛在3座中小型污水处理厂各个工艺单元中均未被检出外,其余12种目标化合物的检出频率在90%~100%之间。进水水样中PPCPs的平均检出浓度为2 285.4 ng/L,其中咖啡因(CF)的平均检出浓度最高为973.3 ng/L,酮洛芬(KP)的平均检出浓度次之为844.7 ng/L,两者之和占进水水样中PPCPs平均含量的79.5%,表明污水处理厂的主要污染物为CF和KP。3座污水处理厂对CF的去除效果最为显著,平均去除率为95.3%,对15种PPCPs总去除效率在39.3%~82.8%之间。     

可凝结颗粒物采样系统的优化设计及实测应用

燃煤电厂烟气中可凝结颗粒物(CPM)主要由无机成分组成,其排放会影响大气环境。为有效捕集烟气中CPM并研究其无机组分排放特性,采用自主优化设计的CPM采样装置,就国家大气污染防治重点区域内3台600 MW等级以上超低排放燃煤机组开展了烟气中CPM实测研究,同时对采样装置的有效性、可靠性进行了探讨。该装置利用半导体材料进行制冷,与常规采样装置相比体积轻巧、便于携带、捕集效率高、冷凝效果好,且使用成本低。研究结果表明：燃煤电厂中A、B、C 3个机组烟囱排口的CPM质量浓度分别为2.22、3.02、3.83 mg·m⁻³;CPM无机水溶性离子中,阴离子主要有SO₄²⁻、Cl⁻等,阳离子主要有Ca²⁺、Na⁺、NH₄⁺等;其中,SO₄²⁻质量浓度占比均大于50%,在水蒸气存在的情况下,会与NH₄⁺产生硫酸氢铵和硫酸铵;而硫酸氢铵易与烟气中的水蒸气结合形成酸雾,会腐蚀烟气管道,还会因其黏附性较强附着飞灰等杂质在管道表面沉积附着,加剧管道的腐蚀和结垢。本研究结果可为探究超低排放燃煤电厂烟气中CPM的排放特性提供参考。     

Monitoring air quality with lichens: a comparison between mapping in forest sites and in open areas

Four different methods of epiphytic lichen mapping were used for the assessment of air quality in the region under the influence of the Sostanj Thermal Power Plant (Salek Valley, Slovenia). Three methods were based on the presence of different lichen species (VDI, EU and ICP-Forest), the fourth on a frequency and coverage assessment of different growth forms of epiphytic lichens, e.g. crustose, foliose and fruticose (SI). A comparison of the results from the assessment of air quality between forest sites (ICP-Forest, SI) and open areas (VDI, EU and SI), obtained by the different methods of epiphytic lichen mapping, is presented in the contribution. Data showed that lichen species richness is worse in forest sites in comparison with open areas. From the data obtained it can be concluded that epiphytic lichen mapping in open areas is a better method for the assessment of air pollution in a given area than mapping in forest sites. The species-based methods in open areas are more powerful and useful for air quality assessment in polluted research areas than the SI and ICP-Forest methods.     

An experimental study of soil conservation using herbaceous plants in Majuli Island, Assam, India

A model experiment on soil conservation utilising the plantation of certain herbaceous plants in a selected stretch of Majuli, the largest riverine island in the world, was carried out. The plantation followed work to establish the proper inclination for the river bank. The soil erosion in the experimental site was reduced to only about 2% compared with about 15–20% in the previous years. All the four species selected for the present study had excellent soil binding capacity and were thus helpful in stabilizing the highly vulnerable soil in the flood plain areas of the region.     

Human viral pathogens are pervasive in wastewater treatment center aerosols

Wastewater treatment center(WTC) workers may be vulnerable to diseases caused by viruses, such as the common cold, influenza and gastro-intestinal infections. Although there is a substantial body of literature characterizing the microbial community found in wastewater, only a few studies have characterized the viral component of WTC aerosols,despite the fact that most diseases affecting WTC workers are of viral origin and that some of these viruses are transmitted through the air. In this study, we evaluated in four WTCs the presence of 11 viral pathogens of particular concern in this milieu and used a metagenomic approach to characterize the total viral community in the air of one of those WTCs. The presence of viruses in aerosols in different locations of individual WTCs was evaluated and the results obtained with four commonly used air samplers were compared.We detected four of the eleven viruses tested, including human adenovirus(h Ad V),rotavirus, hepatitis A virus(HAV) and Herpes Simplex virus type 1(HSV1). The results of the metagenomic assay uncovered very few viral RNA sequences in WTC aerosols, however sequences from human DNA viruses were in much greater relative abundance.     

Evaluation Of Ambient Air Pollution Impact On Carrot Plants At A Sub Urban Site Using Open Top Chambers

The present experiment was done to evaluate the impact of ambient air pollution on carrot (Dacus carotavar. Pusa Kesar) plants using open top chambers (OTCs) ventilated with ambient (NFCs) or charcoal filtered air (FCs) at a suburban site of Varanasi, India. Various morphological, physiological and biochemical characteristics of the plants were studied at different growth stages. Air monitoring data clearly showed high concentrations of SO₂, NO₂and O₃in the ambient air of study site. SO₂and NO₂concentrations were higher during early growth stages of carrot, whereas O₃concentration was highest during later growth stages. Filtration of air has caused significant reductions in all the three pollutant concentrations in FCs as compared to NFCs.Plants growing in FCs showed significantly higher photosynthetic rate, stomatal conductance, water use efficiency and variable fluorescence as compared to plants growing in NFCs. Protein content also showed a similar pattern, however, lipid peroxidation, ascorbic acid content and peroxidase activity were higher in plants growing in NFCs as compared to FCs. Shoot length, number of leaves per plant, leaf area and root and shoot weight increased significantly upon filtration of ambient air. Total nitrogen decreased significantly in root, but increased significantly in shoot of plants grown in NFCs. Total P, Mg, Ca and K contents decreased significantly in plants grown in NFCs as compared to FCs. The individual pollutant concentrations were below threshold for plant injury, but the combined effect of all the three seems to act synergistically in causing greater adverse impact on dry weight and physiology of carrot plants. The study clearly indicates that air pollutants are high enough in the ambient air to cause significant unfavorable impact on carrot plants. The work further supports the usefulness of OTCs for assessing air pollution damage under field conditions in developing countries.     

Medieval Agroecosystems (9th–13th Centuries) in the Region of the Present-Day City of Glazov (Udmurt Republic)

Paleoethnobotanical materials and buried soils from the site of the ancient settlement of Idnakar and neighboring archaeological monuments were analyzed to reconstruct the agroecosystems of the 9th through the 13th centuries AD near the present-day city of Glazov. The results provided data on the main features of the agroecosystem structure and composition, climate, and agriculture in the Middle Ages.     

Application of the Red List Index for conservation assessment of Spanish vascular plants

The International Union for Conservation of Nature (IUCN) Red List Index (RLI) is used to measure trends in extinction risk of species over time. The development of 2 red lists for Spanish vascular flora during the past decade allowed us to apply the IUCN RLI to vascular plants in an area belonging to a global biodiversity hotspot. We used the Spanish Red Lists from 2000 and 2010 to assess changes in level of threat at a national scale and at the subnational scales of Canary Islands, Balearic Islands, and peninsular Spain. We assigned retrospective IUCN categories of threat to 98 species included in the Spanish Red List of 2010 but absent in the Spanish Red List of 2000. In addition, we tested the effect of different random and taxonomic and spatial Spanish samples on the overall RLI value. From 2000 to 2010, the IUCN categories of 768 species changed (10% of Spanish flora), mainly due to improved knowledge (63%), modifications in IUCN criteria (14%), and changes in threat status (12%). All measured national and subnational RLI values decreased during this period, indicating a general decline in the conservation status of the Spanish vascular flora. The Canarian RLI value (0.84) was the lowest, although the fastest deterioration in conservation status occurred on peninsular Spain (from 0.93 in 2000 to 0.92 in 2010). The RLI values based on subsamples of the Spanish Red List were not representative of RLI values for the entire country, which would discourage the use of small areas or small taxonomic samples to assess general trends in the endangerment of national biotas. The role of the RLI in monitoring of changes in biodiversity at the global and regional scales needs further reassessment because additional areas and taxa are necessary to determine whether the index is sufficiently sensitive for use in assessing temporal changes in species’ risk of extinction.     

The Botanist Effect Revisited: Plant Species Richness, County Area, and Human Population Size in the United States

Abstract:  The "botanist effect" is thought to be the reason for higher plant species richness in areas where botanists are disproportionately present as an artefactual consequence of a more thorough sampling. We examined whether this was the case for U.S. counties. We collated the number of species of vascular plants, human population size, and the area of U.S. counties. Controlling for spatial autocorrelation and county area, plant species richness increased with human population size and density in counties with and without universities and/or botanical gardens, with no significant differences in the relation between the two subsets. This is consistent with previous findings and further evidence of a broad-scale positive correlation between species richness and human population presence, which has important consequences for the experience of nature by inhabitants of densely populated regions. Combined with the many reports of a negative correlation between the two variables at a local scale, the positive relation between plant species richness in U.S. counties and human population presence stresses the need for the conservation of seminatural areas in urbanized ecosystems and for the containment of urban and suburban sprawl.