We investigated rice husk as the sole carbon source as well as biofilm carrier in the biological denitrification of wastewater in up-flow laboratory reactors. Fast startup of the reactor and high nitrate removal efficiency was observed. The highest denitrification rate (about 0.096kg/m·d) was achieved when flow rate and nitrate concentration were 41.4L/d and 25.0mg/L, respectively. Flow rate an...

Little is known about the molecular basis of the influence of external carbon/nitrogen (C/N) ratio and other abiotic factors on phytohormones regulation during seed germination and plant developmental processes, and the identification of elements that participate in this response is essential to understand plant nutrient perception and signaling. Sugars (sucrose, glucose) and nitrate not only a...

This paper reviews both heterotrophic and autotrophic processes for the removal of nitrate from water supplies. The most commonly used carbon sources in heterotrophic denitrification are methanol, ethanol and acetic acid. Process performance for each feed stock is compared with particular reference nitrate and nitrite residual and to toxicity potential. Autotrophic nitrate removal has the advan...

Coastal California is a dynamic upwelling region where nitrogen (N) and iron (Fe) can both limit productivity and influence biogeochemistry over different spatial and temporal scales. With global change, the flux of nitrate from upwelling is expected to increase over the next century, potentially driving additional oceanic regions toward Fe limitation. In this study we explored the effect of ch...

The proportion in which carbon and growth-limiting nutrients are exported from the oceans' productive surface layer to the deep sea is a crucial parameter in models of the biological carbon pump. Based on >400 vertical flux observations of particulate organic carbon (POC) and nitrogen (PON) from the European Arctic Ocean we show the common assumption of constant C:N stoichiometry not to be met....

one distinct concentration of copper ions was embedded into the silica matrix to xerogel form using copper source cu(no3)2∙3h2o. the xerogel samples were prepared with using hydrolysis and condensation reactions of tetraethyl ortho-silicate (teos) by the sol-gel method. in this investigation, new molar ratio of h2o/teos was determined to be 11.7. also, the necessary amount of tri-hydrated coppe...

Removal of ammonia nitrogen and nitrate nitrogen by an heterotrophic nitrification-aerobic denitrification strain is an economical and effective method. In this article, a kind of heterotrophic nitrification-aerobic denitrification strain which has aerobic denitrification and heterotrophic nitrification ability was selected, and then was identified as rhodococcus sp. by 16S rRNA sequencing anal...

BACKGROUND In comparison with phototrophic growth, heterotrophic conditions can significantly increase growth rates, final cell number and cell mass in microalgae cultures. Neochloris oleoabundans is a microalga of biotechnological interest that accumulates lipids under phototrophic and nitrogen-limited conditions. Heterotrophic flask culture experiments were conducted to identify carbon source...