it is extremely challenging to measure first-order rate coefficients for soil nitrate transformation processes directly, either in the laboratory or in the field. in this study, an improved inverse method was proposed to optimize the first-order rate coefficients by considering the intermediate changing processes of the integrated functions. a numerical experiment was designed to test the accur...

Four diverse chlorides layered double hydroxides with diverse ratios, i.e. Mg-Al (3:1), Mg-Al (4:1), Zn-Al (4:1), and Zn-Al (3:1) LDHs, were prepared to evaluate their efficiency and selectivity towards nitrate removal from aquatic solutions. A batch experiment was done at the initial nitrate concentration of 5-1000 mg/L, pH 5 to 12, and contact time of 5-180 min. Isotherms of nitrate adsorptio...

Nitrate sorption potentials of three surface soils (soils-1-3) were evaluated under different solute concentrations, i.e. 1-100 mg L(-1). Batch and diffusion-cell adsorption experiments were conducted to delineate the diffusion property and maximum specific nitrate adsorption capacity (MSNAC) of the soils. Ho's pseudo-second order model well fitted the batch adsorption kinetics data (R(2)>0.99)...

0305-7364/0 * For corre bcgn.grignon. There is still disagreement about whether crop growth rate or soil nitrate concentration control nitrogen absorption by crops under ®eld conditions. The in ̄uence of these factors on the control of N uptake rate was examined in the absence of water stress, using data on dry matter production, above-ground nitrogen accumulation and soil nitrate concentration ...

Hydrogen sulfide (H2S), a major odorous component emitted from construction and demolition debris landfills, has received increasing attention. Although cover materials such as soil and compost are recommended to be used routinely to control an odor problem from the landfills, the problem still remains. Autotrophic denitrification may have environmental applications including treatment of water...

Hydrogen sulfide (H2S), a major odorous component emitted from construction and demolition debris landfills, has received increasing attention. Although cover materials such as soil and compost are recommended to be used routinely to control an odor problem from the landfills, the problem still remains. Autotrophic denitrification may have environmental applications including treatment of water...

the aim of this study is to investigate the nitrate adsorption on granular ferric hydroxide (gfh). the effect of factors such as initial concentration of nitrate, ph, contact time, and adsorbent mass were determined. the study was done in laboratory–scale in which synthetic nitrate solutions in a batch reactor were placed in contact with the adsorbent to model adsorption kinetics. it was found ...

In this chapter, we shall review plant responses to changes in supply of the two inorganic N sources nitrate (NO3 ) and ammonium (NH4 +), with an emphasis on primary mechanisms of transport, and their regulation. The topics discussed here include: soil N resources and their ecological implications for plant life; parallel responses in plant growth and N transport activity as functions of N supp...

Nitrate immobilization into organic matter is thought to require catalysis by the enzymes of soil microorganisms. However, recent studies suggest that nitrate added to soil is immobilized rapidly and this process may include abiotic pathways. We amended living and sterilized soil with 15N-labeled nitrate and nitrite to investigate biotic and abiotic immobilization. We report rapid transformatio...

The photochemical persistence of quinalphos, one of the most widely used organophosphorous insecticides, was investigated in a variety of environmental matrices such as natural waters and soils of different composition. Simulated solar irradiation was obtained using a xenon arc lamp (Suntest CPS+ apparatus) giving an irradiation intensity of 750 W m(-2) equivalent to a light dose per hour of ir...