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1.
Due to the importance of biological safety in drinking water quality and the disadvantages which exist in traditional methods of detecting typical microorganisms such as Cryptosporidium and Giardia, it is necessary to develop an alternative. Particle counts is a qualitative measurement of the amount of dissolved solids in water. The removal rate of particle counts was previously used as an indicator of the effectiveness of a biological activated carbon （BAC） filter in removing Cryptosporidium and Giardia. The particle counts in a BAC filter effluent over one operational period and the effects of BAC filter construction and operational parameters were investigated with a 10 m^3/h pilot plant. The results indicated that the maximum particle count in backwash remnant water was as high as 1296 count/ml and it needed about 1.5 h to reduce from the maximum to less than 50 count/ml. During the standard filtration period, particle counts stay constant at less than 50 count/ml for 5 d except when influenced by sand filter backwash remnant water. The removal rates of particle counts in the BAC filter are related to characteristics of the carbon. For example, a columned carbon and a sand bed removed 33.3% and 8.5% of particles, respectively, while the particle counts in effluent from a cracked BAC filter was higher than that of the influent. There is no significant difference among particle removal rates with different filtration rates. High post-ozone dosage （〉2 mg/L） plays an important role in particle count removal; when the dosage was 3 mg/L, the removal rates by carbon layers and sand beds decreased by 17.5% and increased by 9.5%, respectively, compared with a 2 mg/L dosage. 相似文献
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降低循环水场循环水浊度新方法探究 总被引：1，自引：0，他引：1
针对循环水浊度偏高问题,分析造成悬浮物、浊度升高的原因,通过增加隔油池排泥反洗实验,探究降低循环水浊度的新方法,评价排泥反洗中试装置中,浅层压力式过滤罐与滤池降低浊度的效果对比,在加药和不加药两种情况下,浊度和去除率的情况。 相似文献
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In order to remove the low turbidity present in surface water, a novel metal-polysilicate coagulant was used to treat the raw water taken from Tanjiang River in Guangdong Province. This study on the effects of Al/Fe molar ratio on the performance of a complex compound formed by polysilicic acid, aluminium and ferric salt (PAFS) showed that PAFS with Al/Fe ratio of 10:3 seemed to have the best coagulation performance in removing turbidity and color. Experimental results showed that under the conditions of polymerization time of 15 d, sedimentation time of 12 min, and pH of 6(8, PAFS with Al/Fe molar ratio of 10:3 had the best coagulation efficiency and lowest residual Al concentration. The turbidity decreased from 23.8 NTU to 3.23 NTU and the residual Al concentration was only 0.165 mg/L in the product water. It could be speculated that colloidal impurities and particulate Al were removed by adsorption bridging and electrical neutralization of long chain inorganic polymer coagulants. 相似文献
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费广成 《南通职业大学学报》2013,27(1):74-78
针对地表水富营养化问题,采用多层钢毛滤料对低浊度含藻水进行了直接过滤的试验研究。通过改变滤速、混凝剂种类、混凝剂投加量,设计正交试验,得出多层钢毛过滤处理低浊度含藻水的最佳工艺参数。试验证明,多层钢毛滤料对低浊度含藻水有着非常好的过滤效果。 相似文献
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Study on coagulation property of metal-polysilicate coagulants in low turbidity water treatment 总被引：2，自引：0，他引：2
INTRODUCTION Coagulation-flocculation is a major step inthe potable water treatment for removal of colloi-dal impurity. Due to the increase of water pollu-tion, the standards of drinking water supply andwastewater discharge are becoming more and morestringent, and chemical coagulants that are moreefficient in water treatment are more and moreurgently in demand. As well known, the residual Al in potablewater comes from three main sources: natural wa-ter-body, coagulants used in… 相似文献
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Urban wastewater treatment techniques could not be applied to improve the pollutant removal efficiency,due to its characteristics of closed and quiescent conditions of the static lake water.In this study,natural zeolite and coal cinder were chosen as filler compounds of the ecological filter.Static and dynamic experiments were carried out to study the remediation efficiency.Experimental data show that removal efficiency of ammonia nitrogen （NH ＋ 4 -N） reaches 85% in both static and dynamic patterns and its removal efficiency reaches 97% when the recycling period is 1 h in dynamic condition.The maximum removal efficiency of nitrite nitrogen （NO-2 -N） reached 98%,and the removal efficiency of total nitrogen （TN） is a maximum of 84%.The final effluent concentration of total phosphorus （TP） is 0.079 mg/L.Effluent recycling could improve the nutrient （N,P） removal efficiently.Dissolved oxygen （DO） concentration could remain high with the water cycling.The filter works efficiently on regulating pH to the standard level of healthy water. 相似文献
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为保障西北村镇饮用水安全,选用生物慢滤对窖水进行处理。通过自然挂膜的方式研究了填充铁改性沸石的慢滤柱对浊度、氨氮和CODMn的去除效果,改变滤速和断流天数考察装置的运行能力。研究表明:慢滤柱30天形成生物膜,稳定后能有效去除水中的各项污染物,对浊度、氨氮和CODMn的平均去除率分别为96.67%、87.13%和42.86%;滤速增加各去除率降低;断流后滤柱恢复时间很短;慢滤柱对实际雨水也有很好的去除效果,适用于西北村镇分散式供水。 相似文献
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YANG Kai YANG Xiao-Jun YANG Mo 《浙江大学学报(A卷英文版)》2007,8(5):719-723
Jar tests were conducted to investigate the performance of enhanced primary treatment processes for low-concentra-tion municipal wastewater from South China by using composite flocculant combined with bio-flocculants Pullulan and poly-aluminum-chloride (PAC). The optimum dosage for composite flocculant and conditions for flocculation were determined. The experimental results indicated that composite flocculant had high efficiency for removing over 95% of turbidity, over 58% of CODCr (chemical oxygen demand determined with potassium dichromate), over 91% of TP (total phosphate), and over 15% of NH3-N. Moreover, it could improve sludge settling and dehydration properties, and decrease the treatment cost. 相似文献
10.
杨红丽 《延安教育学院学报》2011,25(5):90-92
通过正交实验确定了制备聚硅酸硫酸铁的最佳反应条件：SiO2的最佳含量是2％,Fe／Si（mol）比为0．7,聚硅酸活化时间30min．聚硅酸pH值=2。其絮凝效果可达98．2％。研究表明,聚硅酸硫酸铁对膨润土悬浊液具有较好的处理效果．优于市售PAC。 相似文献
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通过盐度(32‰、28‰、24‰、20‰、16‰)对三倍体和二倍体太平洋牡蛎Crassostrea gigas呼吸和排泄影响比较的研究表明:在盐度32‰20‰,牡蛎的耗氧率随着盐度降低而降低,在盐度20‰时耗氧率最低,三倍体耗氧率平均为1.345 mg/(g?h),二倍体为1.679 mg/(g?h),之后随盐度降低耗氧率稍有升高。在相同条件下,三倍体和二倍体太平洋牡蛎排氨率出现不同程度升高,在盐度20‰达到最高,三倍体排氨率平均为530.256μg/(g?h),二倍体为360.765μg/(g?h),之后随盐度降低排氨率大幅度降低。以体重为协变量进行协方差分析结果表明:盐度、倍性效应引起耗氧率差异达到显著水平(p<0.01),二倍体太平洋牡蛎耗氧率大于三倍体,盐度引起排氨率差异极显著(p<0.01),倍性效应引起的排氨率差异不显著。 相似文献
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The water distribution system of one residential district in Tianjin is taken as an example to analyze the changes of water quality. Partial least squares (PLS) regression model, in which the turbidity and Fe are regarded as con-trol objectives, is used to establish the statistical model. The experimental results indicate that the PLS regression model has good predicted results of water quality compared with the monitored data. The percentages of absolute relative error (below 15%, 20%, 30%) are 44.4%, 66.7%, 100% (turbidity) and 33.3%, 44.4%, 77.8% (Fe) on the 4th sampling point; 77.8%, 88.9%, 88.9% (turbidity) and 44.4%, 55.6%, 66.7% (Fe) on the 5th sampling point. 相似文献
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常玉广 《南京晓庄学院学报》2013,(3):68-70
该实验以生物絮凝剂为水处理材料,以松花江的水源水为被处理对象,将生物絮凝剂应用到动态流混凝沉淀试验.通过絮凝率验证絮凝剂应用于松花江水的处理效果,絮凝率达到85%,以及生物絮凝剂对浊度和色度有良好的去除效果,分别达到87%和70%,并且UV254去除率达到32%.同时,对松花江的水源水和絮凝后的沉降水进行色谱-质谱联机分析（GC/MS）,比较其中有机物的变化,结果显示,松花江原水中含有邻苯二甲酸二甲酯、邻苯二甲酸二乙酯和硝基苯等优先控制污染物被生物絮凝剂有效去除. 相似文献
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INTRODUCTION Surface EMG signal recorded from the skin surface over limb muscles in the process of limmovement is called action surface EMG (ASEMGsignal. Containing the electrical and functional properties of limb muscle contraction and providing thinformation on the neuromuscular activity fromwhich ASEMG signal originates, ASEMG signal habeen widely applied in rehabilitation and the controlof prosthetic devices for the individuals with amputations or congenitally deficient limbs … 相似文献
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欧阳恒 《福建工程学院学报》2018,(1):17-21
对福州市境内闽江水的水温、水质和水位等重要参数开展测试工作,建立了福州市闽江水源热泵技术应用基础数据库。测试数据显示闽江水温在纵向断面上基本保持一致,相对气温变化稳定,适合作为冷热源。多项水质测试结果显示,主要水质指标均满足水源热泵机组的要求,闽江水存在浊度大和铁离子含量偏高的问题。闽江水位每日变化幅度受潮汐的影响较大,潮差自闽江口向闽江上游逐渐减少,其中马尾段每日最大水位差在2.58~5.34 m之间波动,水位年变化幅度为5.51 m。本研究旨在为福州市闽江水源热泵技术推广应用提供数据支撑。 相似文献
16.
ZHANG Hong-jing LONG Teng-rui CAO Yan-xiao 《重庆大学学报(英文版)》2006,5(3):152-156
1 Introduction ? The biological aerated filter technique has developed rapidly since 1980s, and is widely used in municipal sewage treatment. It has been used in the primary and secondary treatment processes due to its desirable economical efficiency and … 相似文献
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以齐鲁师范学院章丘新校区生活饮用水（自来水、凉开水）和中水为研究对象,以去离子水为对比样品,分别采用分光光度法、玻璃电极法和EDTA滴定法测定了水样的浊度、pH值和总硬度。实验结果表明,新校区的自来水在这三个方面均符合国家规定的饮用水水质标准,中水符合国家规定的建筑中水水质标准。中水的浊度明显高于自来水。自来水和中水的pH值没有明显差别。加热煮沸后,自来水的总硬度明显降低,pH值略有升高。 相似文献
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Tea saponins affect in vitro fermentation and methanogenesis in faunated and defaunated rumen fluid 总被引：4，自引：0，他引：4
INTRODUCTION Livestock is one of the largest sources of meth-ane emission with 80~115 million tons produced peryear, equivalent to 15%~20% of total anthropogenicmethane (IPCC, 2001). The global cattle population isresponsible for 73% of methane emissions of alllivestock, and methane produced during ruminalfermentation represents a loss of 2%~15% of grossenergy intake and may contribute to global warming(Johnson and Johnson, 1995). Many researches hadbeen carried out to find ways to low… 相似文献
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Using interacting multiple model particle filter to track airborne targets hidden in blind Doppler 总被引：1，自引：0，他引：1
DU Shi-chuan SHI Zhi-guo ZANG Wei CHEN Kang-sheng 《浙江大学学报(A卷英文版)》2007,8(8):1277-1282
In airborne tracking,the blind Doppler makes the target undetectable,resulting in tracking difficulties. In this paper,we studied most possible blind-Doppler cases and summed them up into two types:targets' intentional tangential flying to radar and unintentional flying with large tangential speed. We proposed an interacting multiple model(IMM) particle filter which combines a constant velocity model and an acceleration model to handle maneuvering motions. We compared the IMM particle filter with a previous particle filter solution. Simulation results showed that the IMM particle filter outperforms the method in previous works in terms of tracking accuracy and continuity. 相似文献