期刊文献+
共找到20篇文章
< 1 >
每页显示 20 50 100
饮生水感染肺吸虫病的实验研究 被引量:2
1
作者 王承全 杨绍金 +1 位作者 潘会明 王大军 《中国预防医学杂志》 CAS 2008年第7期675-676,共2页
目的探讨饮生水感染肺吸虫病在流行病学中的意义。方法在溪蟹自然感染率较高的溪沟取水找囊蚴,并捕捉溪蟹带回实验室混养和单个饲养,每天换水检查囊蚴。取新解剖的囊蚴测量囊蚴的下沉速度。结果检查溪水浑水样、清水样各50份,约200 L,... 目的探讨饮生水感染肺吸虫病在流行病学中的意义。方法在溪蟹自然感染率较高的溪沟取水找囊蚴,并捕捉溪蟹带回实验室混养和单个饲养,每天换水检查囊蚴。取新解剖的囊蚴测量囊蚴的下沉速度。结果检查溪水浑水样、清水样各50份,约200 L,未检出囊蚴。在盛蟹的容器沉渣和混养、单个饲养的水样中,均在5 d前检出囊蚴,最高在一只单个饲养的溪蟹水样中一次检出囊蚴10个,在一只刚脱下的蟹壳中检到囊蚴一个。测量囊蚴下沉速度为4.285 mm/s。分析在自然环境中由于坎坷不平的溪底,弯曲而落差较大的急流,囊蚴的密度大于水,下沉速度较快,人们饮生水的方法等表明饮用生溪水感染肺吸虫病的可能性和危险性极小。结论饮用生溪水感染肺吸虫病在流行病学中的意义很小或没有流行病学意义。 展开更多
关键词 肺吸虫病 饮生水 感染方式 实验研究
下载PDF
上海将启动欧盟标准优质供水规划 今后可饮生水
2
《给水排水技术动态》 2004年第1期8-9,共2页
一项旨在提高上海自来水质量,最终使水质达到欧盟标准的行动计划——“上海提高供水水质行动大纲”今年将正式付诸实施。根据行动大纲规划,上海对照世界级城市饮水标准,通过原水预处理、水厂深度处理、管网全面改造及二次供水系统梳... 一项旨在提高上海自来水质量,最终使水质达到欧盟标准的行动计划——“上海提高供水水质行动大纲”今年将正式付诸实施。根据行动大纲规划,上海对照世界级城市饮水标准,通过原水预处理、水厂深度处理、管网全面改造及二次供水系统梳理等“四管齐下”,全面提高申城供水水质,到2010年让市民享受到“龙头一开,生水可饮”。 展开更多
关键词 上海 自来水 供水规划 饮生水 供水系统 水质
原文传递
水蛭致鼻腔大出血误诊1例 被引量:1
3
作者 陈喜珪 彭胜国 +2 位作者 覃金红 罗金萍 陶维泉 《中国误诊学杂志》 CAS 2005年第7期1390-1391,共2页
关键词 鼻腔大出血 误诊 水蛭 注意力不集中 病例报告 鼻腔出血 对症处理 医院就诊 卫生纸 60岁 卫生院 后出血 饮生水 右侧 填塞
下载PDF
钩虫感染因素的病例对照研究 被引量:2
4
作者 郭见多 沈光金 +5 位作者 吴维铎 李启扬 尹小梅 周利 季虹 刘晓明 《热带病与寄生虫学》 2004年第2期100-101,109,共3页
目的探索人体钩虫易感因素。方法本研究采用1∶4的个体匹配方法,选择88例钩虫感染者和352名健康对照进行回顾性调查,进行条件 Lgistic 回归模型分析。结果单因素 Logistic 回归分析筛选出使用未处理人畜粪便(X9)、饭前洗手(X10)、便后洗... 目的探索人体钩虫易感因素。方法本研究采用1∶4的个体匹配方法,选择88例钩虫感染者和352名健康对照进行回顾性调查,进行条件 Lgistic 回归模型分析。结果单因素 Logistic 回归分析筛选出使用未处理人畜粪便(X9)、饭前洗手(X10)、便后洗手(X11)、吃洗净瓜果(X12)、饮生水(X14)和赤脚下地劳动(X16)等6个相关因素有显著意义;多因素 Logistic 回归分析表明,最终引入模型的3个因素饮生水(X14)、使用未处理人畜粪便(X9)和家庭总收入(X5)有显著意义(P<0.05)。其 OR 值分别为3.3609、2.4267和0.9998。结论认为影响钩虫感染的主要危险因素是:饮生水、使用未经无害化处理的人畜粪便和家庭经济状况。 展开更多
关键词 病例对照研究 多因素LOGISTIC回归分析 感染因素 回归模型分析 家庭经济状况 回顾性调查 无害化处理 饮生水 易感因素 便后洗手 危险因素 钩虫感染 感染者 粪便 人畜 单因素 总收入 OR值
下载PDF
口腔黏膜层寄生美丽筒线虫1例报告
5
作者 王林杰 《中国乡村医药》 2003年第2期48-48,共1页
关键词 口腔黏膜层寄生美丽简线虫 诊断 治疗 个人卫生 饮生水 预防
下载PDF
Pollution of Environmental Endocrine Disrupting Chemicals(EDCs) in Water and Its Adverse Reproductive Effect on Fish 被引量:3
6
作者 孟顺龙 宋超 +3 位作者 范立民 裘丽萍 陈家长 徐跑 《Agricultural Science & Technology》 CAS 2014年第3期463-469,共7页
Environmental endocrine disrupting chemicals (EDCs), commonly found in the environment, come from industry and agriculture, including pesticides, fungicides, insecticides, herbicides, and other chemicals. Nowadays, ... Environmental endocrine disrupting chemicals (EDCs), commonly found in the environment, come from industry and agriculture, including pesticides, fungicides, insecticides, herbicides, and other chemicals. Nowadays, more and more EDCs were released into the environment. EDCs go into water body via atmosphere sedi-mentation, surface runoff, soil eluviation, etc., so water body becomes the main place for existing. In order to attract scientific and public attention worldwide and to prevent EDCs pol ution, in this study we reviewed the classification of EDCs and their concentrations in natural water bodies, drinking water sources and water plants, and the reproductive toxicity of EDCs to fish were reviewed. EDCs could disturb the endocrine system and make reproductive organs and reproduction abnor-mal, resulting in fertility descending, reproduction function damage, community quan-tity decrease and even species extinction. In addition, EDCs could disrupt the homeostasis maintained by hormones, which would result in defects of neural de-velopment and abnormalities of the endocrine and reproductive systems. The exact molecular mechanisms have not been completely reported, but researches have suggested that multiple mechanisms were involved in the action of EDCs. Although there have been researches on the biohazard of EDCs, there stil exist problems of weakness in fundamental researches, difficulties in recognizing and identifying EDCs and high cost, which restraint the knowledge on them. 展开更多
关键词 Environmental endocrine disrupting chemical Water body Pollution situ-ation FISH Damage of reproduction
下载PDF
Improving AOC degradation rate by intensified biological process in advanced water treatment 被引量:1
7
作者 安东 李伟光 +1 位作者 宋佳秀 崔福义 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2007年第1期93-96,共4页
The object of is to evaluate assimilable organic carbon(AOC) degradation rate by intensified biological technique in advanced water treatment. By artificially acclimating and cultivating strains attached onto carbon... The object of is to evaluate assimilable organic carbon(AOC) degradation rate by intensified biological technique in advanced water treatment. By artificially acclimating and cultivating strains attached onto carbon surface, the selected strains can be intensified for their degradation to organic matters. The research indicates that ozonation process increases AOC concentration considerably, however, it is beneficial to microdegradation. Temperature and empty bed contact time ( TEBC ) are two important factors affecting microbiology. From 14 to 27 ℃, intensified biological carbon can remove AOC better compared with granular activated carbon (GAC). Under identical TERC, intensified technique increases more than 10% AOC reduction. 展开更多
关键词 activated carbon assimilable organic carbon empty bed contact time advanced water treatment
下载PDF
Phosphorus speciation in sediments of Lake Hongfeng, China 被引量:7
8
作者 蒋翠红 胡继伟 +4 位作者 黄先飞 李存雄 邓家军 张杰 刘峰 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2011年第1期53-62,共10页
This study was conducted to evaluate the distribution characteristics of phosphorus and its species in 14 sediments samples collected from Lake Hongfeng based on sequential extraction. Lake Hongfeng, a major drinking-... This study was conducted to evaluate the distribution characteristics of phosphorus and its species in 14 sediments samples collected from Lake Hongfeng based on sequential extraction. Lake Hongfeng, a major drinking-water source for Guiyang City in southwestern China, is one of the largest artificial reservoirs located in a typical karstic area of the Yunnan-Guizhou Plateau. The results of this study indicate that the average percentages of DP, Al-P, Fe-P, Ca-P and OP in the lake sediments were 0.52, 6.59, 6.09, 42.85 and 40.27, respectively. The concentrations of organic phosphorus (OP) were lower than those of inorganic phosphorus (IP), which consisted mainly of calcium-bound phosphorus (Ca-P). The high concentrations of Ca-P may temporarily control the release of phosphorus from the sediments because it is a relatively stable, inert, and non-bioavailable phosphorus fraction. However, a large number of phosphate solubilizing bacteria can transform insoluble phosphate into bioavailable forms. Moreover, the concentrations of total phosphorus (TP) in the lake sediments were high; thus, the potential for the release of phosphorus from the sediments to the water column and phosphorus bioavailability were still significant. Further statistical analyses of the results revealed significant correlations between phosphorus species in sediments from the lake with two extractable principal component species (PCs) and five selectable cluster levels allowing interpretation of possible origins of phosphorus loading and the release of phosphorus. Furthermore, available remediation measures were briefly assessed for the lake with consideration of its distinctive environmental features. 展开更多
关键词 EUTROPHICATION karstic environment lake sediments phosphorus speciation sequential extraction procedure
下载PDF
Hydrochemical Control of Groundwater in an Administrative Area of Mamou
9
作者 Mamadou Dian Kante Chuanping Feng +2 位作者 Cellou Kante Alfa-Sika Mande Seyf-Laye Baogang Zhang 《Journal of Environmental Science and Engineering(B)》 2014年第1期49-54,共6页
The potability of water wells, drilling and tap water is the determining factor for the quality management of health of the urban and rural population. This study has been done on the basis of monitoring aspect such a... The potability of water wells, drilling and tap water is the determining factor for the quality management of health of the urban and rural population. This study has been done on the basis of monitoring aspect such as pH, content ammonium, nitrate, nitrite and chloride from a physico chemical point of view. This study allowed the chemical and bacteriological analysis of samples, based on the result obtained, and the potability of water was defined. The bacteriological analysis was carried out taking account of the total flora, coliforms and Escherichia coll. This work gave rise to analyze 36 samples of water from wells, eight samples of drilling water and nine samples of water taps from municipalities such as Mamou, Dalaba and Pita. Water wells represent 90% of water supplies in drinking water to the population. In this research, collection of samples was very important. This study shows that 16 samples from 52 are potable, therefore, it is urgent to focus on the treatment of sewage in order to ensure better health for the population from administrative region of Mamou. 展开更多
关键词 NITRATES NITRITES total flora.
下载PDF
Israeli Water Achievements Today and Enlightenment to China
10
作者 Sun Lei1,2, Xu Lanqing3 1. Institute of Environmental Science and Engineering, Ocean University of China, Qingdao Shandong 266100, China 2. Department of Soil and Water Sciences, Faculty of Agricultural, Food and Environmental Quality Sciences, the Hebrew University of Jerusalem, 76100, Israel 3. Logistics Group of Ocean University of China, Qingdao Shandong 266100, China 《Chinese Journal of Population,Resources and Environment》 北大核心 2008年第4期72-77,共6页
Despite the endemic drought, arid climate and associated limited freshwater resources, as well as difficult geopolitical realities, Israel can provide a reliable supply of high quality water to a rapidly growing popul... Despite the endemic drought, arid climate and associated limited freshwater resources, as well as difficult geopolitical realities, Israel can provide a reliable supply of high quality water to a rapidly growing population. The achievements of water supply in Israel can be summarized as water technologies (like water transportation and purification, desalination, wastewater treatment, effluent reuse, storm water catchment, control systems, rain enhancement and drip irrigation, etc.), water management and legislation as well as water industry. In view of the national concern regarding the quality and quantity of the water, the skills, technologies and know-how that Israel has accumulated in water supply and irrigation can give us enlightenment that is also presented in this paper. 展开更多
关键词 Israel China water technology water management water industry
下载PDF
Reflection--The Story of Water
11
作者 Marijana Magdic Vlatka Husetovic Mirna Coljak 《Journal of Chemistry and Chemical Engineering》 2017年第3期107-115,共9页
Starting from the fact that water is quite arguably the source of life, the authors agreed to set up a project on water and name it: "REFLECTION". Particular focus was placed on the following issues: water in natu... Starting from the fact that water is quite arguably the source of life, the authors agreed to set up a project on water and name it: "REFLECTION". Particular focus was placed on the following issues: water in nature, importance of water in human life, physical and chemical properties of water, protection of water in nature. The aim of the project was to make students aware of the importance of water for health as well as to help them develop a rational relationship towards drinking water. In order to find answers to the issues raised, the authors designed worksheets, PowerPoint presentations, educational games (ecological postcards, dominoes, memory games, etc.). The authors even tried our hand at making a comic strip. Students learned about the influence of water on health, as well as about water content in particular foods. The long-term goal of the project is to introduce children to scientific approach and methodology. Through active participation and dialogue, students discover cooperative learning and acquire skills that will be beneficial to them as well as to the wider community. Working on the project, students' evidence that the role of an individual is a key one in building a better world. This insight helps develop their civic skills and attitudes that serve as the starting point for environmental education. The authors made numerous adaptations and implemented individual approach with the goal of training students for independent work and life according to their personal abilities in line with the principles of inclusive education. Students conduct experiments following step-by-step instructions on specially adapted worksheets. Each student gets positive feedback and experiences the joy of success that leads to the development of self-confidence and love of work and learning. 展开更多
关键词 Water in nature water content in foods nature protection ECOLOGY education.
下载PDF
Health and Labor Productivity among Female Farmers in Imo State, Nigeria
12
作者 Agulanna Foluso Temitope kpi Anthony Okoruwa Victor Olusegun 《Journal of Agricultural Science and Technology(B)》 2012年第7期856-863,共8页
This study examined the impact of farmers' health on labor data was collected through a field survey of 290 rural households productivity of female farmers in Imo State, Nigeria. Primary Descriptive statistics and es... This study examined the impact of farmers' health on labor data was collected through a field survey of 290 rural households productivity of female farmers in Imo State, Nigeria. Primary Descriptive statistics and estimation of efficiency following maximum likelihood estimation (MLE) procedure available in Frontier 4.1 were used to analyze the data. Results from the analyses showed that malaria has the highest prevalence level among female farmers in the study area followed by typhoid fever. The causes of sicknesses vary from cold, stress, mosquito bites and bad drinking water. Furthermore, the results showed that sicknesses affect the productivity of farmers by reducing their work capacity. Also, the distance to source of drinking water from home, source of drinking water, age, body mass index of farmers are also found to significantly affect the physical work output of farmers in the study area. The result shows that the distribution of farmers was highly skewed with about 99% of the farmers having their efficiency above 0.61. This indicates that majority of the farmers are technically efficient in the allocation of resources to crop production, The result also shows that the average efficiency was about 82.9%. Thus, the farmers' level of efficiency can be improved if there is a shift in the fi'ontier, i.e. if factors contributing to inefficiency are adequately controlled. The study recommends the need to invest more on human capital especially health for there to be an improvement in rural productivity. Also, rural development policies should include health policies especially for women since it has a great influence on the household and emphasis should also be on preventive rather than curative health services. 展开更多
关键词 Labor productivity SICKNESS health status female farmers Imo State.
下载PDF
Influence of dietary Lys levels and dietary net energy levels on growth performance and nitrogen balance of growing pigs
13
作者 CHEN Liu WANG Kang-ning 《Journal of Agricultural Science and Technology》 2009年第6期17-23,共7页
Two experiments were conducted to determine the effects of L y s ine(Lys) and Net Energy (NE) levels on growth performance (Exp. I) and N balance (Exp. 2) in growing pig. In Exp. 1, 36 castrated pigs [21.35 -4... Two experiments were conducted to determine the effects of L y s ine(Lys) and Net Energy (NE) levels on growth performance (Exp. I) and N balance (Exp. 2) in growing pig. In Exp. 1, 36 castrated pigs [21.35 -4- 0.55 kg of body weight (BW)] were allotted to six treatments with six replicates per treatment. Pigs were fed two levels of Lys (low and high) and three levels of NE (low, med, or high) in a 2×3 factorial arrangement. The experiment lasted for 35 d. There were no effects of dietary Lys and NE on pig performance (P〉0.05, but a Lys×NE interaction in ADG was observed (P〈0.05). In Exp. 2, 24 pigs were used to determine the effects of diet in Exp. 1 on pig N balance. Neither Lys nor NE level affected N retention (g/d) (P〉0.0). Lys×NE interaction in N retention (g/d) (P〈0.01) and in N apparent biological value (ABV) (P〈0.05) was observed. Pigs fed the low Lys diet had lower serum urea nitrogen (SUN) concentrations compared with the high Lys treatment (P〈0.01). Pigs fed the med-NE diet had lower SUN concentrations compared with the pigs fed the low-NE diet (P〈0.1). These results suggest that pigs from 21 kg to 50 kg BW fed diets containing 0.83% standardized ileal digestible Lysine and 2351 Kcal of NE/kg had maximum ADG and N retention. 展开更多
关键词 LYSINE net energy PERFORMANCE nitrogen retention growing pigs
下载PDF
Quality Assessment of Drinking Water in Tanta City, Egypt
14
作者 Maha Abdelfattah Khalil Zenhom El-Said Salem +1 位作者 Saly Farouk Gheda Moustafa Mohamed E1-Sheekh 《Journal of Environmental Science and Engineering(B)》 2013年第5期257-275,共19页
The physico-chemical and biological (algal and bacterial) quality of tap water in Tanta City were elucidated. Samples were collected during December 2011, covering all the water plants and the areal extension of the... The physico-chemical and biological (algal and bacterial) quality of tap water in Tanta City were elucidated. Samples were collected during December 2011, covering all the water plants and the areal extension of the pipe line network in Tanta. Total dissolved solids content classifies water origin into surface water, shallow and deep groundwater. Fe, Mn and hardness in some samples of groundwater origin are obviously exceeding the WHO (World Health Organization) limit. Mostly, green algae are found (31 species), followed by diatoms (19 species), then blue-green algae (13 species). CCA (Canonical Corresponding Analysis) indicates that green algae are strongly correlated with pH, NH4, alkalinity, Mn and Si; diatoms with EC (electric conductivity), turbidity, Zn and Si and blue green algae with EC and alkalinity. 50% of samples of surface origin, 80% of samples of both deep and shallow groundwater origins crossed WHO and Egyptian guideline in their content of mean TCC (Total Coliform Count). CCA estimates strong correlations of TCC with temperature, NH4 and PO4; E. coli with EC; heterotrophic bacteria with turbidity and NO3; Salmonella sp. with Si and SO4 and Pseudomonas aeruginosa with Mn. Finally, the water plants treatment may be not effective and pipes serve as a reservoir for pathogenic microorganisms. 展开更多
关键词 Water pollution drinking water physicochemical characteristics ALGAE bacteria.
下载PDF
Groundwater Quality and Arsenic Contamination in Amphoe Khemmarat, Ubon Ratchathani, Thailand
15
作者 Pranee Pattanapipitpaisal t Piyada Suraruk 《Journal of Environmental Science and Engineering(A)》 2012年第2期133-141,共9页
Arsenic (As) is one of the most important elemental pollutants in groundwater and drinking water because it causes health problem of arsenicosis after consumption of drinking arsenic-rich water more than 5-10 years.... Arsenic (As) is one of the most important elemental pollutants in groundwater and drinking water because it causes health problem of arsenicosis after consumption of drinking arsenic-rich water more than 5-10 years. Arsenic contamination of groundwater is an emerging issue in Mekong Basin including Cambodia, Vietnam, and Thailand. In Thailand, information about arsenic contamination in drinking water resources are quite rare due to that arsenic is not the main element in water qualification assay. The objective of this study is to determine groundwater quality and arsenic contamination in rural Mekong Basin, Ubon Ratchathani. Groundwater samples were collected from 20 different sampling points, between August 2009 and February 2010 in Amphoe Khemmarat, Ubon Ratchathani, Thailand. Physical and chemical characteristics of groundwater were determined. It was observed that the groundwater was 27.9-30.3 ~C, pH 5.7-6.9. The conductivity was 707-767 p.S.cm". Dissolved oxygen was 2.04-5.12 mg.L-1 and TDS was 352-384 mg.L~. The samples showed soft- to very hardness-water properties. In some area, few parameters like CI, Fe, Mn, and As exceeded the WHO guideline limits. This result represents basic information for quality of groundwater and the arsenic contamination in rural Mekong Basin, Ubon Ratchathani. Thus, it is probably useful for arsenic standard level assignment and public health authorities. Moreover, it also leads to establish research activity in treatment of arsenic-contaminated groundwater for different purposes 展开更多
关键词 ARSENIC arsenic contamination groundwater quality.
下载PDF
Effects of Minimum Wage Hikes on the Formalization of Employment
16
作者 张军 赵达 周龙飞 《China Economist》 2017年第5期84-98,共15页
Despite the intention of minimum wage policy to maintain the living standards of low-income groups in the formal sector, this paper has found that the actual result of this policy produces the "big push" impact on C... Despite the intention of minimum wage policy to maintain the living standards of low-income groups in the formal sector, this paper has found that the actual result of this policy produces the "big push" impact on China's economy under certain conditions, i.e. it is conducive to achieving the equilibrium of high wage, high consumption and formalization. The result shows that the elasticity of income growth from raising the minimum wage standard is greater for formal sector employees than for informal sector employees and is characterized by a U-shaped pattern in terms of quantiles. Thus, minimum wage hikes have widened wage gaps between and within sectors. Rising minimum wage standards greatly stimulate consumption with each 10% increase expected to bring about an additional urban household consumption of about 1.167 billion yuan in the surveyed four provinces. With local minimum wage hikes, the formal sector of wholesale and retail, hotel and catering services expands and the informal sector contracts, while the real estate sector experiences a "reverse formalization" trend. Based on the "big push theory", this paper concludes that against the backdrop of extensive, frequent and substantial minimum wage hikes, demand and sector TFP growth are the major causes of sector heterogeneity. 展开更多
关键词 minimum wage standards employment formalization of informal sectors TFP product demand
下载PDF
Phytotherapic Potentials of Xylopia aethiopica Dried Fruits (Grains of Selim) as Additive in Broiler Production
17
作者 Jonathan Ogagaoghene Isikwenu John Ewomazino Udomah 《Journal of Agricultural Science and Technology(A)》 2015年第2期122-129,共8页
Xylopia aethiopica dried fruits (gains of selim) as an additive in starter broilers production was investigated. For this purpose, a total of 195-day old broiler chicks (Arbor acres) were randomly allocated into f... Xylopia aethiopica dried fruits (gains of selim) as an additive in starter broilers production was investigated. For this purpose, a total of 195-day old broiler chicks (Arbor acres) were randomly allocated into five treatments groups with 39 chicks and three replicates of 13 chicks in each. Blended grains of selim was given through drinking water on treatments T2, T3, T4 and T5 at concentrations of 0.4, 0.6, 0.8 and 1,0 g/L, while chicks on treatment T1 (control) received antibiotics (Doxy-gen 20/20 WSP: Doxycycline hyclate 200 mg and Gentamicine sulfate 200 mg) at 0.3 g/L of water. All the experimental chicks were fed ad libitum with diet containing 23% crude protein and 2,851.55 kcal/kg metabolizable energy for 28 d. The results revealed that there were similarities (P 〉 0.05) in final body weight, total weight gain, daily weight gain, total feed intake, daily feed intake and feed conversion ratio among the treatments. There were significant (P 〈 0.05) differences in the microbial count of faeces before the birds received antibiotics and grains of selim, but count were similar (P 〉 0.05) after grains of selim and antibiotics were administered. Cost of total feed consumed, cost of per kg feed and cost of per kg weight were significantly (P 〈 0.05) higher in treatment T1, but cost differential and relative cost benefit were similar (P 〉 0.05). Results indicate that grains of selim have antimicrobial and anthelminthic properties, and promote growth in broiler chickens. 展开更多
关键词 Anthelminthic ANTIBIOTICS ANTIMICROBIAL broiler chicks growth promoters phytotherapic Xylopia aethiopica driedfruits (grains of selim).
下载PDF
Optimization of ultrasonic parameters for effective detachment of biofilm cells in an actual drinking water distribution system 被引量:3
18
作者 Hong-xi PENG Yu SHAO +4 位作者 Yi-fu ZHANG Ruo-wei WANG David Z.ZHU Huan-yu CHEN Jing-qing LIU 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2020年第3期167-178,共12页
It is important to obtain a considerable quantity of DNA from oligotrophic environments such as a drinking water distribution system(DWDS)to study microbial communities by molecular biotechnology,and DNA yield is alwa... It is important to obtain a considerable quantity of DNA from oligotrophic environments such as a drinking water distribution system(DWDS)to study microbial communities by molecular biotechnology,and DNA yield is always one of the biggest problems when performing metagenomic sequencing on drinking water samples.To obtain as many microbes as possible,ultrasound has been widely used in cell detachment,but studies on the optimal ultrasonic parameters for biofilm in DWDS have rarely been seen.The effects of three ultrasonic parameters,including power,duration,and the number of ultrasound treatments(USTs)on the selected monoculture bacteria(Pelomonas sp.)biofilm were studied first.Then the optimal values of each ultrasonic parameter were initially determined.Based on these values,three levels of each ultrasonic parameter were selected,and then an orthogonal experiment was conducted to further study drinking water biofilm,and finally the optimal ultrasonic parameters for the effective separation of biofilm cells in DWDS were determined.The results showed that the optimal ultrasonic power,duration,and the number of USTs are 13 W,1 min,and 15,respectively.A 20-min interval is needed between two USTs.The present optimal UST,which does not lose DNA quality,can increase the amount of extractable DNA by at least 4.78 times compared to samples without UST.This study provides a pretreatment methodology for extracting more and reliable DNA from biofilm in DWDS,and can better solve the problem of DNA collection in oligotrophic environments. 展开更多
关键词 BIOFILM Drinking water distribution system(DWDS) DNA yield DNA quality Ultrasound treatment(UST)
原文传递
A Technique for Producing Drinking Water from Air Using Adsorbents Driven by Solar Energy: Theoretical and Experimental Research
19
作者 Chou Qiaoli Su Yuehong +2 位作者 Ge Xinshi Wang Yongtang Cheng Shuxia(Department of Thermal Science and Energy Engineering, University of Science and Technology of China,Hefei, Anhui, 230026, China) 《Journal of Thermal Science》 SCIE EI CAS CSCD 1994年第4期225-228,共4页
A technique for producing driping water from air using adsorbents driven by solar energy is Presented,its principle is described, and its applicability is experimentally verified.
关键词 ADSORPTION producing drinking water from air solar energy.
原文传递
Effect of pipe material and low level disinfectants on biofilm development in a simulated drinking water distribution system 被引量:1
20
作者 Ling-ling ZHOU Yong-ji ZHANG Gui-bai LI 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2009年第5期725-731,共7页
The efficiency of chlorine and chloramines disinfection on biofilm development in a simulated drinking water distribution system was investigated by using heterotrophic bacterial spread plate technique. The experiment... The efficiency of chlorine and chloramines disinfection on biofilm development in a simulated drinking water distribution system was investigated by using heterotrophic bacterial spread plate technique. The experiments were carried out with four annular reactors (ARs) with stainless steel (SS) or copper (Cu) material slides. The results showed that there were fewer bacteria attached to Cu slides without a disinfectant compared with those attached to SS slides. When the water was disinfected with chloramines, the heterotrophic plate counts (HPCs) on the biofilm attached to the Cu slides were significantly lower (by 3.46 log CFU/cm2) than those attached to the SS slides. Likewise, the biofilm HPC numbers on the Cu slides were slightly lower (by 1.19 log CFU/cm2) than those on the SS slides disinfected with chlorine. In a quasi-steady state, the HPC levels on Cu slides can be reduced to 3.0 log CFU/cm2 with chlorine and to about 0.9 log CFU/cm2 with chloramines. The addition of chloramines resulted in a more efficient reduction of biofilm heterotrophic bacteria than did chlorine. We concluded that the chlorine and chloramines levels usually employed in water distribution system were not sufficient to prevent the growth and development of microbial biofilm. The combination of copper pipe slides and chloramines as the disinfectant was the most efficient combination to bring about diminished bacterial levels. 展开更多
关键词 Copper (Cu) Stainless steel (SS) BIOFILM Heterotrophic plate counts (HPCs) CHLORINE CHLORAMINES
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部