نتایج جستجو برای: dissolved oxygen

تعداد نتایج: 232646  

Journal: :Environmental research 1975
R W Clubb A R Gaufin J L Lords

Continuous-flow bioassays were employed to determine the relationship between dissolved oxygen and cadmium upon five species of aquatic insects, as measured by survival and the amount of cadmium found within the insect. Results indicate the toxicity of cadmium increases as the dissolved oxygen concentration increases. This may be explained by an observed increase in the amount of cadmium found ...

Journal: :international journal of environmental research 2011
w.j.s. mwegoha

a mathematical model was developed to predict the effects of wind speed, light, ph, temperature, dissolved carbon dioxide and chemical oxygen demand (cod) on dissolved oxygen (do) in fish ponds. the effects of organic feeds, aeration and fish activity were added to the model developed by kayombo et al. for waste stabilization ponds (ecological modeling 127(2000): 21-31) to reflect the situat...

Journal: :تحقیقات نظام سلامت 0
احمدرضا رهسپار دانشجوی کارشناسی ارشد بهداشت محیط، دانشکده بهداشت، دانشگاه علوم پزشکی اصفهان و شبکه بهداشت داراب، شیراز، ایران. مهدی حاجیان نژاد دانشیار مهندسی بهداشت محیط، مرکز تحقیقات محیط زیست، دانشگاه علوم پزشکی اصفهان، اصفهان، ایران محمد مهدی امین دانشیار مهندسی بهداشت محیط، مرکز تحقیقات محیط زیست، دانشگاه علوم پزشکی اصفهان، اصفهان، ایران. اکبر حسن زاده مربی، گروه آمار و اپیدمیولوژی، دانشکده بهداشت، دانشگاه علوم پزشکی اصفهان، اصفهان، ایران.

background: zayandeh-rood river is the only perennial river in the central basin of iran that has fresh water. water from this source is used for drinking, industrial and agricultural purposes. drinking water is extracted from upstream portion (upstream of chamaseman dam) of zayandeh-rood river and therefore its quality is very important. due to growth of population, industry and other factors,...

2013

Water contains oxygen which may make a human breathe under water like a fish. Centrifugal separator can separate dissolved gases from water. Carrier solution can increase the separation of dissolved oxygen from water. But, to develop an breathing device for a human under water, the enhancement of separation of dissolved gases including oxygen and portable devices which have dc battery based dev...

Journal: :Water environment research : a research publication of the Water Environment Federation 2013
Chong Tan Fang Ma Ang Li Shan Qiu Jianzheng Li

The effects of dissolved oxygen on simultaneous nitrification and denitrification were evaluated in polyurethane foam contact oxidation reactors in a municipal wastewater treatment process. It was observed that nitrate could be removed at low dissolved oxygen levels, but the removal rate was gradually reduced as the dissolved oxygen concentration increased to a higher level of 6.0 mg/L. Nitroge...

2013
Pil Woo Heo

Water contains oxygen which may make a human breathe under water like a fish. Centrifugal separator can separate dissolved gases from water. Carrier solution can increase the separation of dissolved oxygen from water. But, to develop an breathing device for a human under water, the enhancement of separation of dissolved gases including oxygen and portable devices which have dc battery based dev...

Journal: :Engineering, Technology & Applied Science Research 2020

2008
Yesong Gu Chien-Chung Chen

Polyaniline (PANI) has been shown to possess excellent catalytic activity toward oxygen reduction, however, this molecule may interfere with the electrochemical measurement of other targets when using a polyaniline modified platinum (PANI/Pt) electrode. In this study, we have demonstrated the considerable effects of dissolved oxygen on the sensing of hydrogen peroxide with the PANI/Pt electrode...

2002

Dissolved oxygen concentrations in the lower reaches of the Tualatin River in northwest Oregon are the result of many processes. Temperature imposes a seasonal signal through the solubility of oxygen in water. Streamflow determines the travel time through the system and affects the amount of oxygen consumed via processes such as ammonia nitrification and the decomposition of organic material in...

2007
L. Bodizs M. Titica N. Faria B. Srinivasan D. Dochain D. Bonvin

Industrial filamentous fungal fermentations are typically operated in fed-batch mode. Oxygen control represents an important operational challenge due to the varying biomass concentration. In this study, oxygen control is implemented by manipulating the substrate feed rate, i.e. the rate of oxygen consumption. It turns out that the setpoint for dissolved oxygen represents a trade-off since a lo...

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