نتایج جستجو برای: natural and anthropogenic sources

تعداد نتایج: 16910230  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه ارومیه - دانشکده کشاورزی 1393

چکیده کنه تارتن دو لکه ای tetranychus urticae koch یکی از چندخوارترین آفات شناخته شده محصولات کشاورزی دنیا به حساب می آید. در این بررسی جمعیت تخم و مراحل فعال این کنه در شرایط آلودگی طبیعی و مصنوعی در برگ های 8 رقم لوبیا در سال 1392 در گلخانه و مزرعه تحقیقاتی دانشکده کشاورزی دانشگاه ارومیه موردمطالعه قرار گرفت. آزمایش به صورت طرح کاملاً تصادفی برای شرایط مزرعه در10 تکرار و برای شرایط گلخانه ای...

Azizi, Sajad, Besharati, Pouya, Parsinezhad, Shahrzad, Zamani, Pedram Masoud,

Many elements such as Arsenic (As), Cadmium (Cd), Copper (Cu), Chromium (Cr), Lead (Pb), Zinc (Zn), and others are major environmental problems due to their toxic nature, nonbiodegradability and accumulative behaviors. There are anthropogenic or geogenic sources that accumulate or rotate elements in sediments. Sediments served as excellent indicator of metal pollution in coastal environments as...

2008
Yu. A. FEDOROV Yu. A. Fedorov

The sulphur isotope content, ôS, of sulphate from two potential pollution sources in Volga-Akhtuba flood plain surface waters was investigated. Isotope compositions of sulphur compound emissions from the Astrakhan Gas Condensate Complex and the Astrakhan Pulp and Paper Mill were significantly different which provided an opportunity to differentiate effects from these two emission sources on nea...

Journal: :Geochimica et Cosmochimica Acta 1989

2013
Helen M. Amos Daniel J. Jacob David G. Streets Elsie M. Sunderland

[1] Elevated mercury (Hg) in marine and terrestrial ecosystems is a global health concern because of the formation of toxic methylmercury. Humans have emitted Hg to the atmosphere for millennia, and this Hg has deposited and accumulated into ecosystems globally. Here we present a global biogeochemical model with fully coupled atmospheric, terrestrial, and oceanic Hg reservoirs to better underst...

Journal: :Environmental pollution 2002
B Koerner J Klopatek

Recent research has shown the Phoenix, AZ metropolitan region to be characterized by a CO2 dome that peaks near the urban center. The CO2 levels, 50% greater than the surrounding non-urban areas, have been attributed to anthropogenic sources and the physical geography of the area. We quantified sources of CO2 emissions across the metropolitan region. Anthropogenic CO2 emission data were obtaine...

2015
Jun Ren Zhen Shang Ling Tao Xia Wang

The concentrations of heavy metals in 21 samples collected from surface sediments from the Qinghai section of the Yellow were investigated in order to evaluate their distribution and pollution levels. The total concentrations showed wide variations with Cu 11.86~57.02 mg/kg, Fe 17236.67~41340.00 mg/kg, Mn 431.93~877.27 mg/kg, Ni 14.58~86.11 mg/kg, Zn 67.18~149.00 mg/kg, Cr 87.84~169.70 mg/kg, P...

Journal: :international journal of environmental research 0
v.o. ajibola department of chemistry, faculty of science, ahmadu bello university, zaria, nigeria m.k. ladipo department of polymer & textile technology, yaba college of technology, lagos, nigeria

concentrations of eight metals namely, cr, mn, fe, co, ni, cu, zn and pb were examined in the surface sediments of discharge channels of six industries in lagos using x-ray fluorescence spectrometry.these channels drain into the isolo canal which empties into the lagos lagoon and eventually into the atlantic ocean. this study was conducted to detect any contamination levels within the sediments...

Journal: :Chemical Geology 2022

Anthropogenic activities have significantly enhanced atmospheric metal inputs to the ocean, which has potentially important consequences for marine ecosystems. This study assesses potential of Zn and Cu isotope compositions distinguish between natural anthropogenic these metals surface ocean. To this end, isotopic in aerosols collected from eastern tropical Atlantic Ocean on GEOTRACES GA06 crui...

Journal: :international journal of environmental research 0
s. martinez college road, cranfield university, bedfordshire, mk 43 oal, uk m. delgado environmental department, inia, ctra. la coruña km 7.5, 28040 madrid, spain p. jarvis cranfield water science institute, cranfield university, bedfordshiremk 43 oal, uk

in the last twenty years, due to a number of natural and anthropogenic reasons, many water sources have become poorer in quality with respect to micropollutants. an example of a micropollutant that needs to be removed is the chlorophenoxypropionic herbicide mecoprop (mcpp). mcpp is one of the nine pesticides used as an indicator to monitor pesticide concentrations in rivers because it is freque...

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