Homologues of the amtB gene of enteric bacteria exist in all three domains of life. Although their products are required for transport of the ammonium analogue methylammonium in washed cells, only in Saccharomyces cerevisiae have they been shown to be necessary for growth at low NH4+ concentrations. We now demonstrate that an amtB strain of Escherichia coli also grows slowly at low NH4+ concent...

The reduction of ammonia (NH3) emissions is urgently needed due to its role in aerosol nucleation and growth causing haze formation during its conversion into ammonium (NH4(+)). However, the relative contributions of individual NH3 sources are unclear, and debate remains over whether agricultural emissions dominate atmospheric NH3 in urban areas. Based on the chemical and isotopic measurements ...

(Effects of different ammoniacal nitrogen sources on N-metabolism of the atmospheric bromeliad Tillandsia pohliana Mez). Increasing levels of atmospheric ammonia from anthropogenic sources have become a serious problem for natural vegetation. Short-term effects of different ammoniacal sources on the N metabolism of Tillandsia pohliana, an atmospheric bromeliad, were investigated. One-year-old, ...

This paper presents a study on the use of best management practices (BMPs) for controlling nonpoint pollution in the Xikeng Reservoir watershed located in Shenzhen, China. A BMP treatment train design, including a pond, a wetland, and a buffer strip placed in series was implemented at the reservoir location. A separate grass swale was also constructed at the site. Low impact development (LID) B...

The aim of this paper is to evaluate the efficiency of nutrients removal by Chlorella vulgaris (C. vulgaris). The study is comprised of five different fractions, having different quantities of C. vulgaris. From the batch reactor operations it was observed that increasing the content of C. vulgaris in the wastewater caused an apparent increase of removal rates in biochemical oxygen demand (BOD),...

Ion exchange is a reversible process. Thus, once the media becomes exhausted, it can be regenerated and the resin is returned to its original ionic form for reuse. Regeneration involves pollutants desorption from the media using processes that drive the pollutants from the media without destroying it. In previous studies, cation exchange resin was used for mature municipal landfill leachate tre...

Hyperammonemia is a key factor in the pathogenesis of hepatic encephalopathy (HE) as well as other metabolic encephalopathies, such as those associated with inherited disorders of urea cycle enzymes and in Reye's syndrome. Acute HE results in increased brain ammonia (up to 5 mM), astrocytic swelling, and altered glutamatergic function. In the present study, using fluorescence imaging techniques...

Silages made from directly cut or wilted Digitaria eriantha treated with or without molasses were evaluated to determine fermentative characteristics. The grass was harvested at the boot stage of growth and the material was ensiled in 1 kg mini-silos. Treatments were arranged in a factorial design of two moisture levels (directly cut or wilted) and two molasses addition (with or without molasse...

This paper describes a new method for the recovery of high-concentration ammonia from water in form ammonium chloride, hydroxide and carbonate. The was applied to Solvay process, which sodium bicarbonate is produced through reaction ammoniated brine CO2 gas. effluent contains soluble chloride. proposed based on using high-alkalinity reactant, calcium oxide (CaO), closed electrocoagulation cell ...

Adrizal, P.H. Patterson, R.M. Hulet, and R.M. Bates Department of Poultry Science, and Department of Horticulture, Penn State University, University Park, PA 16802 Abstract Two experiments were conducted to evaluate the potential of plant species to trap NH3 discharged from poultry houses. The four plant species (cedar, locust, poplar, and grass) used in experiment (Exp) 1 and four species (spr...