活性污泥微生物群落结构及与环境因素响应关系分析

对已发表的62个来自国内外污废水处理设施中活性污泥的16S rRNA扩增子数据进行数据发掘和分析,旨在揭示不同进水性质、温度及处理工艺对应的污泥菌群结构特性.结果表明,活性污泥中整体有着较高的物种多样性和群落丰富度,不同活性污泥样品微生物群落结构有一定差异,样品中常见的优势菌属有Thauera、Nitrospira、Comamonas、Dechloromonas、Rhodoferax、Aquihabitans 和Acidovorax等.温度与Nitrospira、Aquihabitans、Terrimonas和Dechloromona等多种关键的脱氮微生物呈负相关,当温度低于15℃时,32座污水处理厂对TN和NH₄⁺-N的去除率仅有49.67%和63.19%.BOD₅/COD值越大的污水处理系统,Zoogloea、Arcobacter、Acidovorax和Acinetobacter等优势功能性菌属相对丰度也越高,污染物的去除率也越高.对于生活污水的处理,A²O工艺性能要优于OD、CAS和CMAS工艺,Comamonas、Rhodoferax、Nitrospira和Novosphingobium等多种功能性优势菌属的相对丰度要高于其它3类工艺.     

污水处理厂中有机磷酸酯的研究进展

有机磷酸酯(OPEs)作为阻燃剂和增塑剂被广泛用于建筑、电子、化学和纺织等行业中。由于有机磷酸酯大多以物理方法掺加于产品中,更易被释放进入环境中。有机磷酸酯具有神经毒性、致癌性和基因毒性,关于有机磷酸酯产生、迁徙和削减的研究受到了学界的广泛注意。污水处理厂作为地表水环境中污染物的重要来源,在有机磷酸酯进入环境的过程中发挥了重要作用。本文总结了各国污水处理厂中有机磷酸酯研究现状,随着技术的发展被监测的有机磷酸酯种类越来越多;欧洲国家污水中有机磷酸酯检出的最高浓度普遍高于其他国家和地区;极性有机磷酸酯更倾向于转移至污水中,非极性的更倾向于吸附到污泥中;氯代有机磷酸酯普遍去除率很低,有的经过污水处理工艺反而增加,烷基和芳基有机磷酸酯有较高的去除率。     

Chemical Composition of the Leaves of Plants with Different Ecological Strategies from the Boreal Zone

The content of main chemical components (total nitrogen and carbon, soluble and polymeric sugars, organic acids, and mineral substances) were studied in the leaves of 73 boreal plant species with different types of Grime–Ramenskii strategies. The type of ecological strategy was demonstrated to be related to the chemical composition of the leaf, with the substances studied falling into two groups. The concentrations of the substances belonging to the first group (nitrogen, organic acids, and mineral substances) were minimum in stress-tolerant and maximum in ruderal species. With respect to the type of strategy, these concentrations increased in the following series: S C R. Conversely, the concentrations of the substances of the second group (carbon and soluble sugars) decreased in this series. The nitrogen concentration and the carbon-to-nitrogen concentration ratio in leaves may be used for identifying the types of strategies.     

饮料植物的开发利用

通过对华东主要饮料市场的调研,结合国内外的相关报道,就饮料植物在人民生活中的地位、饮料植物种类、开发利用现状进行了综述,并提出利用前景.     

Survival,reproduction, and recruitment of woody plants after 14 years on a reforested landfill

With the advent of modern sanitary landfill closure techniques, the opportunity exists for transforming municipal landfills into urban woodlands. While costs of fullscale reforestation are generally prohibitive, a modest planting of clusters of trees and shrubs could initiate or accelerate population expansions and natural plant succession from open field to diverse forest. However, among woody species that have been screened for use on landfills, these ecological potentials have not yet been investigated. We examined a 14-yr-old landfill plantation in New Jersey, USA, established to test tolerance of 19 species of trees and shrubs to landfill environments. We measured survivorship, reproduction, and recruitment within and around the experimental installation. Half of the original 190 plants were present, although survival and growth rates varied widely among species. An additional 752 trees and shrubs had colonized the plantation and its perimeter, as well as 2955 stems of vines. However, the great majority (>95%) of woody plants that had colonized were not progeny of the planted cohort, but instead belonged to 18 invading species, mostly native, bird-dispersed, and associated with intermediate stages of secondary plant succession. Based on this evidence, we recommend that several ecological criteria be applied to choices of woody species for the restoration of municipal landfills and similar degraded sites, in order to maximize rapid and economical establishment of diverse, productive woodlands.     

EVAPOTRANSPIRATION FROM WATER HYACINTH (Eichhomia crassipes (Mart.) Solms) IN TEXAS RESERVOIRS1

ABSTRACT: Water hyacinth, an attractive, floating aquatic plant, poses a substantial threat of unanticipated water loss from Texas reservoirs. A mature plant will lose about three times as much water through evapotranspiration as is lost from evaporation of an equivalent area of open water. The reservoirs of east and southeast Texas, which comprise the bulk of the state's existing and planned water storage capacity, seem likely to suffer a 20 percent average surface infestation of water hyacinth. A coverage that great will result in a yearly net loss of over 2,000,000 acre-feet of impounded water, based on present water development plans for the state. This would amount to nearly 20 percent of the anticipated yield from the reservoirs affected. An effective aquatic plant control program could head off the threat of this significant water loss.     

Water treatment by aquatic ecosystem: Nutrient removal by reservoirs and flooded fields

Potential use of reservoirs and flooded fields stocked with aquatic plants for reduction of the nutrient levels of organic soil drainage water was evaluated. The treatment systems include 1) a large single reservoir (R1) stocked with waterhyacinth (Eichhornia crassipes), elodea (Egeria densa), and cattails (Typha sp.) in series; 2) three small reservoirs in series with waterhyacinth (R2), elodea (R3), and cattails (R4), grown in independent reservoirs; 3) a control reservoir (R5) with no cultivated plants; 4) a large single flooded field planted to cattails; 5) three small flooded fields in a series planted to cattails; and 6) a flooded field with no cultivated plants. Drainage water was pumped daily (6 hours a day, and 6 days a week) into these systems for a period of 27 months at predetermined constant flow rates. Water samples were collected at the inlet and outlet of each treatment system and analyzed for N and P forms.The series of reservoirs stocked with aquatic plants functioned effectively in the removal of N and P from agricultural drainage water, compared to a single large reservoir. Allowing the water to flow through the reservoir stocked with waterhyacinth plants with a residence time of 3.6 days was adequate to remove about 50% of the incoming inorganic N. Allowing the water to flow through a series of two small reservoirs, R2 and R3, with a residence time of 7.3 days was necessary to remove about 60% of the incoming ortho-P. Flooded fields were effective in the removal of inorganic N, but showed poor efficiency in the removal of ortho-P.Florida Agricultural Experiment Stations Journal Series No. 2320.     

STATUS REPORT ON HEAT STORAGE WELLS1

ABSTRACT. The Heat Storage Well concept evolved at TEMPO in 1972. Technical, economic, institutional, and legal aspects of implementing the concept are being studied. Heat Storage Wells offer the possibility of conserving a substantial part of the heat energy now wasted in generating electricity and of reducing thermal pollution caused by the waste heat. Large thermal electric power plants would produce heat at useful temperatures such as 300–400°F. Combined electric- and heat-generating systems will require low-cost, low-loss storage of large amounts of hot water for periods of 90 to 180 days to serve both electric loads and seasonally-varying heat loads. Compared to conventional electricity-only systems, combined electricity-heat systems can save more than 20 percent in energy, reduce the cost of both electricity and heat, and eliminate the need for cooling water or towers. Possibilities for changes in legal and institutional practices are suggested, such as making resource-allocation decisions on the basis of energy units rather than dollars.     

ON THE CAPACITY-EXPANSION OF DESALINATION PLANTS AND STORAGE TANKS1

ABSTRACT A mathematical programming model is structured to find the optimal time and capacity expansion path of desalination plants and storage tanks for a hypothetical community which depends on desalination as its sole, or major, water supply source. The objective is to determine the least costly combination of sues and times of installation (of both desalting plants and storage tanks) which can meet a rising water demand over a finite planning horizon. The optimality criterion used in the model is based on two major economic elements: the economies of scale inherent in such facilities and the time-value of money represented by the interest rate, the former favoring large capacities and the latter small capacities. The model is applied using three population growth patterns and two interest rates. The water demand components for every year in the planning period are computed using empirical formulas which are based on population and other basic data. The model is solved for each of the above cases with the aid of a computer program based on the method of feasible conjugate directions. The results clearly reflect the balance between the economies of scale and the time-value of money under every demand growth function.     

REVIEW OF LAKE RESTORATION PROCEDURES1

ABSTRACT Relevant information on the restoration of lakes is presented. The restoration procedures considered are applicable to the water, the bottom sediments, and aquatic plant improvement. A summary of thirteen (13) suggested methods of restoration are reviewed.