Humic substances are a collection of colored organic acids characterized by high molecular weight and low nitrogen (N) content that are thought to be biologically recalcitrant. We examined a suite of nonaxenic estuarine phytoplankton isolates to determine their ability to take up 15N-labeled humic substances formed in the laboratory and supplied as the sole N source. All 17 estuarine and coasta...

Humic substances and other dissolved organic matter (DOM) in Lake Biwa and the surrounding rivers were investigated to elucidate their origins and behavior. An annual increase in chemical oxygen demand (COD) has been observed in the northern basin of Lake Biwa since 1985. The concentrations of dissolved organic carbon (DOC) in the northern and southern basins of Lake Biwa were 1.7-2.4 mgC/l and...

ABSTRACT- In the past few decades, accumulation of heavy metals, such as lead (Pb), in soils has increased as a result of human activities.The environmental hazard associated with soil enrichment in heavy metals is related to their mobility and plant availability. Application of various materials such as humic may influence the amount of Pb taken up by plant. Four levels of each of liquid and s...

Thermodynamic stability constants of the formation of complexes from the reactions of humic substances with various metals are usually used as parameters to judge the reactivities of both humic substances and metals. However, in calculating the thermodynamic stability constants, complicated processes for the acquisition of activities of components in reactions are absolutely inevitable. In this...

Currently with the progression of the pollution in water sources, considerable attention has been given to the application of membrane filtration technology using microfiltration or ultrafiltration membranes to the surface water treatment as an alternative to conventional coagulation sedimentation and sand filtration. The microfiltration and ultrafiltration membranes are appropriate for complet...

A class of organic molecules extracted from atmospheric aerosol particles and isolated from fog and cloud water has been termed HUmic-LIke Substances (HULIS) due to a certain resemblance to terrestrial and aquatic humic and fulvic acids. In light of the interest that this class of atmospheric compounds currently attracts, we comprehensively review HULIS properties, as well as laboratory and fie...

In this study, the ultrafiltration membrane for humic substance removal was prepared by blending polysulfone with a high concentration of PEG400 as additives. The influences of the additive to the fouling resistance capability and humic substances rejection of the polysulfone membrane were investigated. The addition of 35%wt of PEG400 concentration improved the pure water flux up to 200, but re...

ARTICLE INFO ABSTRACTIn the past few decades, accumulation of heavy metals, such as lead (Pb), in soils has increased as a result of human activities.The environmental hazard associated with soil enrichment in heavy metals is related to their mobility and plant availability. Application of various materials such as humic may influence the amount of Pb taken up by plant. Four levels of each of l...

This paper deals with the results from experiments concerning the effects of an increasing shear rate at the edge of the membrane on reducing concentration polarization and on controlling membrane fouling during filtration of river water. Concentration polarization of humic substances in NF and MF membranes can be reduced by increasing the shear rate. The concentration polarization model can pr...