Behavioural toxicity in zebrafish (Danio rerio) exposed to waterborne zinc and chromium(VI)

This study is to investigate the behavioural responses of zebrafish to the toxic effects of waterborne zinc and chromium(VI). Swimming performance of fish was tracked by a real-time toxicity bio-monitoring system and transformed into data to calculate individual and fish school behavioural endpoints. Behavioural responses under metals were in accordance with the Stepwise Behavioural Response model. Significant and concentration-dependent effects on swimming speed and turning times were found at concentrations equal to or higher than 3.5 mg L^-1 for zinc and 0.7 mg L^-1 for chromium. Swimming height significantly declined in concentrations equal to or higher than 3.5 mg L^-1 under zinc exposure, while for the chromium treatment, it significantly increased in lower concentration exposures and decreased in higher concentration exposures. Average distance and dispersion of fish school decreased at the beginning but there were no obvious changes during the whole exposure period. Behavioural responses under metal exposures were time-dependent: avoidance (increased speed and turning times and decreased average distance and dispersion) might be the first response and followed by height changes. Changes in behavioural endpoints ‘swimming speed and height’ can be used as early stress responses for acute aquatic metal contamination as part of ecological risk assessment.     

斑马鱼群体行为变化用于水质在线预警的研究

采用计算机摄像跟踪技术,以正常水体中斑马鱼鱼群的行为变化为基础,模拟污染物突发暴露下斑马鱼鱼群游动行为(速度和高度)、通讯行为(平均距离和分散度)和区域分布(不同区域停留时间)的变化规律.结果表明:在氯氰菊酯和溴氰菊酯联合突发暴露下,斑马鱼表现出慌乱不安的过度活跃,游动速度在暴露前30 min内持续增大,变化区间由暴露前30～60 mm·s-1增至60～85 mm·s-1,而后又迅速下降至20mm·s-1左右.高度的变化稍微滞后于速度的突变,在暴露12 min后才明显增高.持续的污染物暴露和其对鱼的毒性作用也破坏了鱼群原有的通讯和分布规律,平均距离和分散度分别增大43.5%和120.0%,且鱼群在浓度相对较低、接近水面的出水口附近的停留时间明显增加.与传统的以个体鱼和单一行为反应为监测对象的方式相比,基于斑马鱼群体行为变化用于水质在线预警系统能够获得更加全面、有效的信息,是预警水质突变的可靠手段.     

室内游泳池围护结构结露机理与预防措施

室内游泳池池厅空气相对湿度大,与室外空气相比,往往存在湿差,若处置不当,围护结构内表面及其内部易出结露．甚至发生霉变。从理论上分析产生这一现象的机理,并从建筑构造、通风、冷却除湿等角度提出预防结露的措施。     

A METHODOLOGY FOR OUTDOOR RECREATION ANALYSIS IN A STATE WATER RESOURCES PLANNING STUDY1

ABSTRACT: The paper presents a methodology for outdoor recreation analysis in a comprehensive State water resources planning study. This methodology applies to determination of recreation participation desires among the population, allocation of those desires to areas of potential resources within which they must be satisfied, comparison of the areal potential resources against the allocated desires to identify areas having recreational resource deficits or needs, and exploration of alternative solutions to the identified needs. Major elements discussed are: market area, inflow-outflow, resource desire determination and projection, resource desire allocation, facility inventory, resource desire-resource analysis and alternative solutions to identified needs of water-oriented outdoor recreation.     

土壤脲酶和脱氢酶对活性X-3B红污染暴露的耐受性及机理研究

采用微宇宙实验方法,研究了棕壤、褐土、红壤等3种我国典型土壤中脲酶和脱氢酶对染料活性X-3B红污染的耐受性及其机理.实验结果表明,3种土壤中的脲酶和脱氢酶活性在试验较低浓度的活性X-3B红污染的环境中均被促进,但被促进的程度有所差异,具体表现为棕壤脲酶活性被促进的效果最为明显,其次红壤,褐土最弱;较低浓度的活性X-3B红污染对褐土脱氢酶活性的促进作用最强,其次红壤,棕壤最弱.3种土壤的脲酶和脱氢酶活性被促进的效果随着时间的推移逐渐减弱.3种土壤的脲酶和脱氢酶活性对高浓度的活性X-3B红污染并没有显示受抑制的趋势.相反,二者基本维持在未受染料活性X-3B红污染的对照土壤的活性水平.因此可以初步认为,土壤脲酶和脱氢酶对染料活性X-3B红的污染暴露毒性有耐受作用.基于实验结果,还就2种酶对活性X-3B红污染暴露的耐受机理进行了分析与探讨.     

泳动床/好氧颗粒污泥新技术处理生活污水的特性研究

基于生物膜法和活性污泥法的联合工艺技术,开发了泳动床/好氧颗粒污泥污水处理新技术.试验阶段,泳动床/好氧颗粒污泥技术表现出高效处理生活污水和实现污泥减量的显著特性.在水力停留时间HRT为3.2 h, COD负荷与NH⁺₄-Ｎ负荷分别为2.03 　kg/(m^３·d) 和0.52 　kg/(m^３·d)时,分别获得COD 90.9%和NH⁺₄-Ｎ 98.3%的平均去除效果.系统运行16 d开始出现好氧颗粒污泥,颗粒呈球形、椭球形和棒形,试验阶段混合液悬浮固体浓度MLSS最高达5 640 mg/L, MLVSS/MLSS平均高达0.87.此外,镜检表明好氧颗粒污泥与生物膜均聚集大量的原生动物和后生动物,形成较长和较稳定的食物链,有利于污泥减量,运行过程中污泥产率（MLSS/COD_removed）为0.175 5,仅为普通好氧工艺的50%左右.     

数控正弦振动试验指要

振动试验引入数字控制技术后,正弦振动试验在试验装备、试验应用和试验工程诸多方面有了提升和拓展.对试验的理念和基础知识都提出了新的要求.本文就引入数字控制技术后试验的要点进行阐述.     

人工泳池水质的模糊综合评判及分析

用模糊数学方法 ,处理人工泳池水质监测数据 ,综合评判泳池水质状况 ,分析水质参数间关系 ,探讨了该方法应用的可能性     

基于换乘人耐受限的对向公交换乘生存距离模型研究

为揭示对向公交换乘距离与换乘乘客横穿道路的相互关系,约请272名受试者,完成城市公交汽车换乘试验。基于换乘试验统计出横穿马路人数,采用非参数估计方法估计换乘乘客的最大忍耐换乘距离,利用SPSS软件,构建拟合程度最高的对向换乘生存距离二次项函数模型,并对模型的有效性进行验证。结果表明,违规过街行人数随公交换乘距离的增大而增多;生存率随换乘距离的增大呈现"缓慢减小-迅速减小-平缓减小"的变化趋势,换乘距离增加至126 m后,越来越多的乘客难以接受这样的距离;换乘距离相同时,男性相比女性更容易横穿马路;根据构建的对向公交换乘生存距离模型,85%的换乘乘客可接受的换乘距离为124 m,50%的换乘乘客可接受的换乘距离为174 m。     

南荻对土壤铅污染的耐性与吸收积累研究

通过土壤盆栽试验,研究了不同浓度梯度pb2＋胁迫下南获整个生长发育周期的生长、土壤理化性状的变化以及不同生长阶段的根系固定重金属含量变化的过程,结果表明：（1）种植南获植物的土壤pH值随着月份的变化呈减小趋势;（2）种植南获的土壤中铅随植物的生长逐渐减少;（3）南获对重金属铅的积累顺序为：根〉叶〉茎,对土壤中重金属的修复机理主要是通过根系固定作用。