Atrazine, metolachlor, carbaryl, and chlorothalonil are detected in streams throughout the U.S. at concentrations that may have adverse effects on benthic microbes. Sediment samples were exposed to these pesticides to quantify responses of ammonium, nitrate, and phosphate uptake by the benthic microbial community. Control uptake rates of sediments had net remineralization of nitrate (-1.58 NO3 ...

introduction:nitrate entrance to water bodies can cause eutrophication and decrease quality of them, furthermore it can effect on human health so concentration of nitrate must be at defined standard level. there are several methods for reduction or removal of nitrate in water such as ion exchange, reverse osmosis, electrodialysis and denitrification. microbial denitrification of nitrate in anox...

The growth and photosynthesis of Alexandrium tamarense (Lebour) Balech in different nutrient conditions were investigated. Low nitrate level (0.0882 mmol/L) resulted in the highest average growth rate from day 0 to day 10 (4.58 ¥ 10 cells mL d), but the lowest cell yield (5420 cells mL) in three nitrate level cultures. High nitrate-grown cells showed lower levels of chlorophyll a-specific and c...

Background: Surface water and groundwater pollution with various forms of nitrogen such as ammonium and nitrate ions is one of the main environmental risks. The major objectives of this study were to evaluate the capacity of natural zeolite (clinoptilolite) to remove NO3- and NH4+ from polluted water under both batch and column conditions. Methods: The laboratory batch and column experiments we...

In this study, the use of TiO2/SiO2 nanocomposites investigated to remove nitrate and total ironfrom wastewater. The nanoparticles and nanocomposites were characterized by the Brunauer, Emmett, and Teller (BET), Field Emission Scanning electron microscopy (FESEM), Fourier transform infrared (FTIR),  X-ray diffraction (XRD) and X-ray fluorescence (XRF). According to the BET...

In this study, the use of TiO2/SiO2 nanocomposites investigated to remove nitrate and total ironfrom wastewater. The nanoparticles and nanocomposites were characterized by the Brunauer, Emmett, and Teller (BET), Field Emission Scanning electron microscopy (FESEM), Fourier transform infrared (FTIR),  X-ray diffraction (XRD) and X-ray fluorescence (XRF). According to the BET...

In this work, removal of ammonia from synthetic wastewater using integrated fixed-film activated sludge (IFAS) process was optimized using response surface methodology (RSM). The main operating parameters such as ammonia concentration rate (ALR) and hydraulic retention time (HRT) were optimized to acquire the maximum removal efficiency. The linear, 2FI, quadratic, mean, and cubic models were ut...

Introduction: Ammonia in form of ammonium ions is toxic and could decrease the dissolved oxygen in water and endanger the aquatic life. The aim of this study is the removal of ammonium using oxidation and adsorption by catalytic ozonation and clinoptilolite zeolite, respectively. Methods: The research method is Experimental. First, optimal pH of ammonium adsorption on carbon catalyst (5 g/L), ...