The present study examines the role of humic acid, as a representative of dissolved organic matter, in Cd(II), Cu(II), and Pb(II) speciation and biouptake by green microalgae. Cellular and intracellular metal fractions were compared in the presence of citric and humic acids. The results demonstrated that Cd and Cu uptake in the presence of 10 mg L(-1) humic acid was consistent with that predict...

Objective:  In addition to the role of organic matter in plant nutrition, this material improves soil quality, physical structure, ventilation and water supply, and ease of penetration and expansion is rooted deep in the soil surface. Effects of organic matter due to climatic factors, soil characteristics may vary from region to region, resulting in organic materials management must be given to...

objective:  in addition to the role of organic matter in plant nutrition, this material improves soil quality, physical structure, ventilation and water supply, and ease of penetration and expansion is rooted deep in the soil surface. effects of organic matter due to climatic factors, soil characteristics may vary from region to region, resulting in organic materials management must be given to...

Background: Natural organic matters (NOMs) have the main role in formation of trihalomethanes. These compounds are in natural water sources due to biological activities. In the presented study, adsorption and separation of humic acid as an index of natural organic matters using multi-walled carbon nanotubes is evaluated. Methods: The experiments were carried out in bath adsorption reactors wit...

Humic acids and clays are important soil components that influence the sorption and desorption of organic contaminants; however, it is unclear how humic acids influence the sorption of organic contaminants onto clays and their subsequent desorption. Sorption and desorption of 2,4,6-trichlorophenol (2,4,6-TCP) by and from humic acid-modified K(+)- and Ca(2+)-montmorillonite and -illite were comp...

the adsorption thermodynamic characteristic of cu2+ from aqueous solution onto humin andalso humic acid from a typical black soil in northeast china were examined at three different temperatures(298, 318 and 338 k) by batch isotherm experiments. results showed that humin was structurally differentfrom humic acid. the increase of temperature had a positive effect on the adsorption process. freun...

wheat crop, considering its high planting area and consumption at national scale, demand a regular yield increase. humic acid, as an organic acid obtained from humus and organic sources without any environmental destructive effects, improves wheat yield particularly in variable environment conditions. in order to evaluate the effects of different levels of humic acid on shoot and wheat yield, a...

introduction cultivated sunflower is one of the largest oilseed crops in the world. sunflower seed is the third largest source of vegetable oil worldwide, following soybean and canola. nitrogen is one of the most important elements for crops to achieve optimum yields and quality. phosphorus (p), next to nitrogen, is often the most limiting nutrient for crop and forage production. phosphorus ava...