نتایج جستجو برای: sand concentration

تعداد نتایج: 407669  

2014
Xiaopeng Jia Haibing Wang

The interaction of wind and water in semiarid and arid areas usually leads to low-frequency flash flood events in desert rivers, which have adverse effects on river systems and ecology. In arid zones, many aeolian dune-fields terminate in stream channels and deliver aeolian sand to the channels. Although aeolian processes are common to many desert rivers, whether the aeolian processes contribut...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه صنعتی خواجه نصیرالدین طوسی - دانشکده علوم 1391

abstract in the present research solution of chalcopyrite in sulfuric acid in hydrometallurgy method using electrochemistry with cyclic voltammetry technique has been investigated. the value of maximum reduction peak current of copper ions represents the measure of solubility. in this research different parameters temperature, potential, potential exert time, chalcopyrite concentration, sulfur...

ژورنال: طلوع بهداشت یزد 2016
ابراهیمی, افشین, خدا رحمی, مهرداد, رحمتی, عزت اله, عبداله نژاد, علی, مهدوی, مختار,

Introduction: Heavy metals owing to their health hazards and high toxicity in low concentration for human and environment have very concern and attention. Slow sand filter is one of the simple and cost-effective for removal of these pollutants. In this method, media play an important role for removal of pollutant. Therefore, the aim of this study was investigation of different media like slag, ...

Journal: :تحقیقات آب و خاک ایران 0
مهسا جمشیدی دانشجوی کارشناسی ارشد دانشگاه بین المللی امام خمینی (ره) پیمان دانش کار آراسته استادیار دانشگاه بین المللی امام خمینی) ره) عباس ستوده نیا استادیار دانشگاه بین المللی امام خمینی) ره)

application of outflow water from treatment plants for irrigation as a non-usual water resource is being developed due to the lack of usual water resources in iran. activated carbon as a conditioner in water treatment procedures causes undesired changes in hydraulic properties of porous media and soil degradation. in this paper, the effects of activated carbon concentration on hydrodynamic prop...

Journal: :Journal of environmental quality 2005
S A Bradford M Bettahar

Accurate knowledge of the transport and deposition behavior for pathogenic Cryptosporidium parvum oocysts is needed to assess contamination and protect water resources. Experimental and modeling studies were undertaken to examine the roles of attachment, detachment, and straining on oocyst transport and retention. Saturated column studies were conducted using Ottawa aquifer sands (U.S. Silica, ...

2012
a. Waseem a. alam m. irshad m. a. sabir m. umar

Faridullah, a. Waseem, a. alam, m. irshad, m. a. sabir and m. umar, 2012. leaching and mobility of heavy metals after burned and burned poultry litter application to sandy and masa soils. Bulg. J. Agric. Sci., 18: 733-741 application of poultry litter to cropland may increase metal mobility, because the soluble organic ligands in poultry litter can form water-soluble complexes with metals. The ...

2015
Scott A. Bradford Brendan Headd Jiří Šimůnek Jacob Blaustein

Tracer and indicator microbe runoff experiments were conducted to investigate the influence of solution chemistry on the transport, retention, and release of Escherichia coli D21g. Experiments were conducted in a chamber (2.25 m long, 0.15 m wide, and 0.16 m high) packed with ultrapure quartz sand (to a depth of 0.10 m) that was placed on a metal frame at slopes of 5.6%, 8.6%, or 11.8%. Runoff ...

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The growing population led to greater human need to use natural resources such as sand and gravel mines. Direct removal of sands from the bed river leads to increase suspended sediment concentrations in downstream of harvested area and creates other problems viz. filling reservoirs, change in hydraulic characteristics of the channel and environmental damages. However, the range of temporal and ...

Journal: :Water, Air, and Soil Pollution 2009
David B. Clark Falk Feddersen Melissa M. Omand R. T. Guza

Decisions about recreational beach closures would be enhanced if better estimates of surfzone contaminant transport and dilution were available. In situ methods for measuring fluorescent Rhodamine WT dye tracer in the surfzone are presented, increasing the temporal and spatial resolution over previous surfzone techniques. Bubbles and sand suspended by breaking waves in the surfzone interfere wi...

2010
Joseph P. Hornak Gianni Ferrante Andrew Coy Evan R. McCarney

The 1 H nuclear magnetic resonance (NMR) spin-lattice relaxation rate of hydrated sands is related to the surface-to-volume ratio of the voids or pores between the hydrated sand grains and the surface relaxivity of the grains. The electron spin resonance (ESR) signal is often used to predict the relative surface relaxivity as the surface relaxivity is thought to be proportional to the concentra...

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