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低温低浊水质特性的分析 总被引:17,自引:4,他引:17
@霍明昕¥吉林建筑工程学院@刘馨远¥哈尔滨建筑大学我国北方广大地区有长达5~6个月的冰封期,水质长时间处于低温低浊状态。江河水温在0~1℃,水库水下层水温2~4℃;江河水浊度为5~30mg/L,水库水浊度为5~10mg/L。在冬季,水质的物理化学特性与其它... 相似文献
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《Planning》2015,(9)
针对冰封期水库水体具有独特特征及冬季市区供水存在异味问题,在2012年11月至2013年2月期间,对处于冰封期的呼和浩特市水源地金海水库的理化指标和浮游藻类进行了监测,并将其结果与夏季监测值进行了对比分析,得出了其变化趋势。结果表明:水库水质良好,但存在轻度污染;水体中共检测到浮游藻类6门24属27种,其主要优势种为绿藻、硅藻和隐藻;相关性分析表明叶绿素a(Chla)、总磷(TP)与浮游藻类数量呈正相关关系,而总氮(TN)则无明显的相关性,溶解氧(DO)和透明度(SD)均呈负相关关系;冰封期水体的理化指标与夏季的相比,高锰酸钾指数(CODMn)、TN和TP值较大,而Chla、pH和SD值略小;夏季的浮游藻类数量明显高于冬季,但不同的季节优势种类存在区别,由此可得冰封期水质较差与浮游藻类的种类和数量存在一定的联系。 相似文献
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以水库水作为饮用水水源的宁波,在台风影响下水库水质污染类型复杂。通过对水库底泥和溪流底泥的对比研究发现,上游溪流底泥比水库底泥污染严重,溪流底泥中氨氮含量呈"表层低、底层高"分布;台风引发的上游溪流底泥扰动会引起水库水的浊度、氨氮、CODMn含量升高,水源水出现的污染与溪流底泥的扰动密切相关;水库底泥由于受到水源地良好的保护,受到扰动后,对上覆水水质的影响微弱;在台风影响下水源水出现的突发性铁污染与底泥扰动无关;为减弱上游流域底泥受到的潜在污染,可以在上游流域保护区内进行生态移民、退耕还林、建立生态缓冲带、关闭工业源等措施,防止各类污染物进入溪流底泥,从而减弱上游底泥在台风扰动下对水源水质造成的污染。 相似文献
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从季节性差异分析了我国东北某城市两座水源地水库的浊度、CODMn氨氮、UV254三卤甲烷生成潜能(THMFP)、叶绿素a的变化规律.结果表明,B水库原水水质要好于A水库,两座水库原水浊度、有机物和三卤甲烷前驱物含量均呈季节性变化;A水库CODMn最高值为6.5 mg/L,最低值为2.8 mg/L;B水库CODMn最高值为5.0 mg/L,全年的最低值0.5 mg/L出现在3月;B水库叶绿素a在春夏之交变化较明显,A水库和B水库六个月内叶绿素a的平均值分别为36.53和22.25 mg/m3,UV254平均值分别为0.11和0.112 cm-1. 相似文献
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《青岛理工大学学报》2016,(4)
在分析国内外供水管网水质研究现状的基础上,对管网水的浊度特性及演变规律进行了深入研究,总结了饮用水浊度指标在管网中的变化规律,并据此筛选出对管网水浊度变化影响较大的三方面因素,即流速、水龄、总铁含量.在对主要因素进行连续监测的基础上,运用MATLAB分别构建BP和RBF神经网络模型对管网水浊度进行模拟分析,结果表明模拟值与实测值吻合良好,RBF神经网络的非线性逼近能力更强,预测精度更高. 相似文献
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在我国城市持续推进绿色发展理念的背景下,为科学支撑海绵城市规划编制工作,以梧州市苍海湖为研究实例,结合国内外相关研究经验和属地化的测量参数,应用InfoWorks ICM构建研究区水量水质数学模型。设计旱季和雨季两种模拟情景,分别对苍海湖汇水区内的污染物径流冲刷效应和湖体内污染物迁移扩散规律进行模拟分析,计算不同设计情景下地表污染物随雨水径流进入苍海湖及在湖内扩散的演进过程,并基于计算结果为苍海湖水动力条件改善、湖泊水质保护等提出工程指引建议,以期为水量水质数学模型在海绵城市规划中的应用提供参考。 相似文献
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建立了一种基于三层结构BP神经网络的混凝投药量前馈控制模型,采用烧杯试验数据进行了仿真验证,同时建立了传统的线性回归混凝投药量前馈控制模型,并采用两种模型基于同一样本数据进行仿真。从投药预测值一实际值的对比图和均方根误差等可以看出,BP模型优于回归模型,它通过学习可以根据原水水质进行投药量的有效预测,有一定的自适应性,实用性较强,但也存在一定的局限性,对某些水质的投药预测值还存在一定误差。 相似文献
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Quantification and relative comparison of different types of uncertainties in sewer water quality modeling 总被引:2,自引:0,他引:2
Willems P 《Water research》2008,42(13):3539-3551
Quantifiable sources of uncertainty have been identified for a case study of integrated modeling of a sewer system with a more downstream wastewater treatment plant and storage sedimentation tank. The different sources were classified in model input and model-structure-related uncertainties. They were quantified and propagated towards the uncertainty in the event-based prediction of sewer emissions (flow, and physico-chemical water quality concentrations and loads). Based on the concept of variance decomposition, the total prediction uncertainty was split into the contributions of the various uncertainty sources and the different submodels. Although the results strongly depend on the water quality variable considered, it is in most general terms concluded that the uncertainty contribution by the water quality submodels is an order of magnitude higher than that for the flow submodels. Future model improvement should therefore mainly focus on water quality data collection, which would reduce current problems of spurious model calibration and verification, but also of knowledge gaps in in-sewer processes. 相似文献
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The wet/dry tropics of the Australian savannas are particularly prone to fire due to the highly seasonal rainfall and accumulation of grassy fuels. The effect of an early dry season wildfire (May, 1998) on the water quality of a seasonally flowing stream (December-June) was examined for a lowland savanna forest in Kakadu National Park (northern Australia) which had remained unburnt for 10 years. The water quality variables assessed were: total and volatile suspended sediment, phosphorus, nitrogen, iron and manganese. Compared to three years of pre-fire water quality data and 5 years of stream flow data, there was no detectable impact of the wildfire on the volume of stream flow, mean concentrations and the total mass transported by the stream for each water quality variable, except possibly nitrogen. The limited effect on water quality is attributed primarily to the timing of the wildfire and the low intensity relative to fires later in the dry season (September). The retention of canopy cover and the accumulation of leaf litter following the wildfire, and the catchment's gently undulating terrain all contributed to the negligible impact on water quality. Early dry season fires appear to be a viable management option for reducing accumulated fuel loads and hence reducing the risk of destructive wildfires later in the dry season. 相似文献
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The Bangpakong River is the most important watershed in the Eastern part of Thailand. Water quality parameters were sampled from June 1998 through May 1999 at 11 sites along a 227 km gradient, covering the wet season (June-November) and the dry season (December-May). Surface water was collected at three different stations per site (close to the banks and in the middle of the river), and analyzed for temperature, dissolved oxygen, turbidity, suspended solids, pH. ammonia, fecal coliforms, biochemical oxygen demand and chemical oxygen demand as well as conductivity, phosphate, and heavy metals. The Scottish water quality index (WQI) was adaptated to the tropical environment. The averaged WQI was low (41%) and quality declined significantly during the dry season (ANOVA, p<0.001). Although the quality rose somewhat at middle sites, only 27% of the WQI values during wet season and 2.5% during dry season were higher than 50%, denoting poor environmental quality. Within each season, the main sources of variability were the differences between sites along the gradient (48% during the wet season, 63% during the dry season), whereas monthly variability represented less than 20% of the variability. The seasonal results show that the river is suitable only for tolerant fish and wildlife species and is of doubtful use for potable water supply during the dry season. As quality improves during the wet period, water can be used for the production of potable water, but only with advanced treatment, and for indirect and noncontact recreational activities. In the middle stretches of the river, higher water quality permits multiple uses at moderate cost. 相似文献
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将遗传算法的全局搜索能力和BP神经网络的局部学习能力有机结合,得到一种快速高效的建立供水管网余氯的水质模型的新方法。验证结果表明,遗传算法优化后的神经网络模型所需要考虑的参数较少,应用方便,预测精度和效率较高,在城市给水系统水质模拟预测研究中有一定的参考应用价值。 相似文献
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鉴于城市景观河流受沿河排水污染,水质波动较大,建立了内嵌神经网络的一维不确定性水质模型,利用改进适应度函数的遗传算法,优化水质模型的参数解.经实例验证,不确定性水质模型拟合的精度更高,对排入污染物的波动更敏感,其对景观河流水质预测的平均准确度基本在80%以上,普遍高于确定性水质模型,尤其是在靠近污染源的监测断面,其不确... 相似文献