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101.
肖鸿  杨平  郭勇 《四川环境》2005,24(2):4-7,10
本实验采用新型厌氧—好氧一体化反应器处理高浓度有机废水,主要研究了系统的启动与运行性能,并对系统的NH3 N去除效果作了初步考察。实验结果表明:在16℃~24℃的自然温度下,采用递增负荷、厌氧和好氧分期启动的方式,系统可在38天内达到较好的启动效果;在系统负荷运行期内,当系统总进水COD浓度平均值为3601 8mg/L,总出水COD浓度平均值为384 0mg/L,系统容积负荷平均值为2 54kgCOD/(m3·d),系统总HRT平均值为35 1h时,系统总COD去除率平均值达90 6%。实验还发现:当进水NH3 N浓度为280 3~350 7mg/L,整个系统的NH3 N去除率在68 5%~91 7%,平均为81 0%。由此说明,本反应器具有很好的COD去除性能和NH3 N去除效果,适合于处理COD浓度高且含有中等NH3 N浓度的有机废水。  相似文献   
102.
垃圾焚烧飞灰中重金属的固化/稳定化处理实验研究   总被引:3,自引:0,他引:3  
研究了城市生活垃圾焚烧-电灰的特性及飞灰中重金属的特性,对利用水泥作粘结剂进行飞灰固化/稳定化处理效果开展了系统的实验研究,分析了水泥固化/稳定化飞灰的工艺特点和最佳工艺参数,并讨论了粘结剂固化飞灰机理以及重金属浸出毒性,为进一步研究城市生活垃圾焚烧飞灰的无害化处理与利用提供了有重要价值的参考依据.  相似文献   
103.
Summary We often do not realize how fast the time is running. It is now more than a year since the sad news for the death of William Ross Adey came. With kind agreement of Prof. Kostarakis my presentation at the 3rd International Workshop “Biological Effects of Electromagnetic Fields” was dedicated to the memory of this remarkable scientist, dear colleague and friend. I would like that this paper will be a tribute to the life and scientific achievements of Dr. Ross Adey. It is astonishing that among all his contributions in the field of Bioelectromagnetics, Dr. Adey introduced the term “window”.  相似文献   
104.
In the global campaign against biodiversity loss in forest ecosystems, land managers need to know the status of forest biodiversity, but practical guidelines for conserving biodiversity in forest management are lacking. A major obstacle is the incomplete understanding of the relationship between site primary productivity and plant diversity, due to insufficient ecosystem‐wide data, especially for taxonomically and structurally diverse forest ecosystems. We investigated the effects of site productivity (the site's inherent capacity to grow timber) on tree species richness across 19 types of forest ecosystems in North America and China through 3 ground‐sourced forest inventory data sets (U.S. Forest Inventory and Analysis, Cooperative Alaska Forest Inventory, and Chinese Forest Management Planning Inventory). All forest types conformed to a consistent and highly significant (P < 0.001) hump‐shaped unimodal relationship, of which the generalized coefficients of determination averaged 20.5% over all the forest types. That is, tree species richness first increased as productivity increased at a progressively slower rate, and, after reaching a maximum, richness started to decline. Our consistent findings suggest that forests of high productivity would sustain few species because they consist mostly of flat homogeneous areas lacking an environmental gradient along which a diversity of species with different habitats can coexist. The consistency of the productivity–biodiversity relationship among the 3 data sets we examined makes it possible to quantify the expected tree species richness that a forest stand is capable of sustaining, and a comparison between the actual species richness and the sustainable values can be useful in prioritizing conservation efforts.  相似文献   
105.
Ornamental horticulture has been identified as an important threat to plant biodiversity and is a major pathway for plant invasions worldwide. In this context, the family Cactaceae is particularly challenging because it is considered the fifth most threatened large taxonomic group in the world; several species are among the most widespread and damaging invasive species; and Cactaceae is one of the most popular horticultural plant groups. Based on the Convention on International Trade in Endangered Species of Wild Flora and Fauna and the 11 largest online auction sites selling cacti, we documented the international cactus trade. To provide an in‐depth look at the dynamics of the industry, we surveyed the businesses involved in the cactus trade in South Africa (a hotspot of cactus trade and invasions). We purchased seeds of every available species and used DNA barcoding to identify species to the genus level. Although <20% of this trade involved threatened species and <3% involved known invasive species, many species were identified by a common name. However, only 0.02% of the globally traded cacti were collected from wild populations. Despite a large commercial network, all South African imports (of which 15% and 1.5% were of species listed as threatened and invasive, respectively) came from the same source. With DNA barcoding, we identified 24% of the species to genus level. Based on our results, we believe that if trade restrictions are placed on the small proportion of cacti that are invasive and there is no major increase in harvesting of native populations, then the commercial trade in cactus poses a negligible environmental threat. However, there are currently no effective methods for easily identifying which cacti are traded, and both the illicit harvesting of cacti from the wild and the informal trade in invasive taxa pose on‐going conservation challenges.  相似文献   
106.
Non‐native species cause changes in the ecosystems to which they are introduced. These changes, or some of them, are usually termed impacts; they can be manifold and potentially damaging to ecosystems and biodiversity. However, the impacts of most non‐native species are poorly understood, and a synthesis of available information is being hindered because authors often do not clearly define impact. We argue that explicitly defining the impact of non‐native species will promote progress toward a better understanding of the implications of changes to biodiversity and ecosystems caused by non‐native species; help disentangle which aspects of scientific debates about non‐native species are due to disparate definitions and which represent true scientific discord; and improve communication between scientists from different research disciplines and between scientists, managers, and policy makers. For these reasons and based on examples from the literature, we devised seven key questions that fall into 4 categories: directionality, classification and measurement, ecological or socio‐economic changes, and scale. These questions should help in formulating clear and practical definitions of impact to suit specific scientific, stakeholder, or legislative contexts. Definiendo el Impacto de las Especies No‐Nativas  相似文献   
107.
春季生物作用对山地岩溶池水地球化学特征的影响   总被引:3,自引:1,他引:2  
岩溶水文系统对外界环境变化敏感,使得岩溶区水质存在昼夜、小时甚至分钟等尺度的变化.许多地表水体都会经历p H值、溶解性气体、微量元素以及其他水化学指标的昼夜变化.重庆金佛山水房泉及受其补给的水池地处海拔2 050 m的山地岩溶区,具有温带气候特征.通过对水房泉泉水(以下简称泉水)及水池进行为期3 d的昼夜监测,以期探究春季生物作用对岩溶池水地球化学的影响.研究发现,在昼夜时间尺度上,泉水地球化学指标基本稳定,未表现出昼夜变化,池水地球化学指标化学表现出了昼夜波动,但水温、溶解氧、p H值、电导率等物理化学指标昼夜变化幅度较小.在不同的天气条件下,水温、溶解氧、Cl-等昼夜变化幅度存在差别;池水二氧化碳分压(p CO2)、Ca2+、DIC白天降低、晚上升高,方解石饱和指数(SIc)相反;这些指标的变化受控于温度、碳酸盐岩矿物的溶解与沉淀、水生植物光合作用与呼吸作用;通过亨利常数的计算,发现水温变化对p CO2变化的影响仅占0.79%~10.01%,水温、碳酸盐岩沉淀等物理因素对DIC损失量的贡献率为39%,水生植物光合作用的贡献率为61%.  相似文献   
108.
制革废水和印染废水的综合毒性评估及鉴别   总被引:3,自引:3,他引:0  
黄利  陈文艳  万玉山  郑国娟  赵远  蔡强 《环境科学》2015,36(7):2604-2609
研究采用成组生物毒性试验(发光菌急性毒性、斑马鱼幼鱼急性毒性,斑马鱼胚胎发育毒性和小球藻急性毒性),结合理化指标,通过毒性单位、平均毒性(average toxicity,Av Tx)、毒性指数(toxic print,Tx Pr)、最敏感的测试(most sensitive test,MST)和潜在毒性效应指数(potential ecotoxic effects probe,PEEP)对不同工艺阶段印染及制革废水进行毒性削减评估.结果表明PEEP能兼顾废水排放量与毒性效应,更为客观地表征了废水综合毒性,PEEP评价结果显示制革废水和印染废水的毒性削减率分别达到36.8%和23.2%.最后,以发光菌作为受试生物,采用毒性鉴别评估(toxicity identification evaluation,TIE)技术,对印染废水进行毒性鉴别.结果表明,印染废水中主要的致毒物质为非极性有机污染,其次为可滤性化合物,然后是重金属、氧化性物质以及挥发性物质.  相似文献   
109.
微气泡臭氧催化氧化-生化耦合工艺深度处理煤化工废水   总被引:7,自引:1,他引:6  
刘春  周洪政  张静  陈晓轩  张磊  郭延凯 《环境科学》2017,38(8):3362-3368
采用微气泡臭氧催化氧化-生化耦合工艺对煤化工废水生化出水进行深度处理,考察耦合系统处理性能及不同臭氧投加量和进水COD量比值的影响.结果表明,微气泡臭氧催化氧化处理能够有效降解废水中难降解含氮芳香族污染物,去除部分COD并释放氨氮,显著提高废水可生化性,臭氧利用率接近100%,无需进行臭氧尾气处理;同时为生化处理提供充足溶解氧(DO),实现生化处理对COD和氨氮的进一步有效去除,生化处理无需曝气.在系统出水回流比为30%、臭氧投加量和进水COD量之比为0.44 mg·mg~(-1)的运行条件下,耦合系统处理性能较好.微气泡臭氧催化氧化处理对COD去除率为42.5%,臭氧消耗量与COD去除量比值为1.38 mg·mg~(-1),臭氧利用率为98.0%;生化处理对COD去除率为42.3%;耦合系统整体COD去除率为66.7%,最终平均出水COD浓度为91.5 mg·L~(-1),估算整体臭氧消耗量与COD去除量比值为0.68 mg·mg~(-1),具有较优的技术经济性能.  相似文献   
110.
污泥基生物炭对垃圾渗滤液的吸附性能研究   总被引:1,自引:1,他引:0       下载免费PDF全文
以城镇污水处理厂剩余污泥为原料制备生物炭,研究了其对垃圾渗滤液中污染物吸附性能,旨在探索市政污泥综合利用方法和"以废治废"的治理技术途径。结果表明:当生物炭投加量为20 g/L时,垃圾渗滤液的COD和TP去除效果最佳,去除率分别为36.76%和78.36%,NH_4~+-N去除率随生物炭投加量增加而增加;上述三者不同污染物去除的最佳反应接触时间分别为50 min、30 min和≥2 h;生物炭对重金属离子的吸附机理主要表现为离子交换作用。  相似文献   
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