Humic Acid-Oxidizing, Nitrate-Reducing Bacteria in Agricultural Soils

This study demonstrates the prevalence, phylogenetic diversity, and physiology of nitrate-reducing microorganisms capable of utilizing reduced humic acids (HA) as electron donors in agricultural soils. Most probable number (MPN) enumeration of agricultural soils revealed large populations (104 to 106 cells g−1 soil) of microorganisms capable of reducing nitrate while oxidizing the reduced HA analog 2,6-anthrahydroquinone disulfonate (AH2DS) to its corresponding quinone. Nitrate-dependent HA-oxidizing organisms isolated from agricultural soils were phylogenetically diverse and included members of the Alphaproteobacteria, Betaproteobacteria, and Gammaproteobacteria. Advective up-flow columns inoculated with corn plot soil and amended with reduced HA and nitrate supported both HA oxidation and enhanced nitrate reduction relative to no-donor or oxidized HA controls. The additional electron donating capacity of reduced HA could reasonably be attributed to the oxidation of reduced functional groups. Subsequent 16S rRNA gene-based high-density oligonucleotide microarray (PhyloChip) indicated that reduced HA columns supported the development of a bacterial community enriched with members of the Acidobacteria, Firmicutes, and Betaproteobacteria relative to the no-donor control and initial inoculum. This study identifies a previously unrecognized role for HA in stimulating denitrification processes in saturated soil systems. Furthermore, this study indicates that reduced humic acids impact soil geochemistry and the indigenous bacterial community composition

Removal of inorganic trace contaminants by electrodialysis in a remote Australian community

Water provision for developing countries is a critical issue as a vast number of lives are lost annually due to lack of access to safe drinking water. The presence and fate of inorganic trace contaminants is of particular concern. Trace inorganic contaminants have been found in elevated concentrations in drinking waters supplied directly from brackish groundwaters in developing countries. Desalination and the removal of trace inorganic contaminants from bore water sources from a remote community in Australia using electrodialysis (ED) were investigated. The influence of applied voltage on the removal of the trace contaminants was evaluated. While the results from this study demonstrated that ED is an effectual method for the removal of total dissolved solids and a number of trace inorganic contaminants from brackish groundwaters to below drinking water guideline levels, the deposition of trace contaminants on the membranes (fouling) influenced the ED process in relation to ionic flux and the effectiveness of trace contaminant removal

Application of Chemically Accelerated Biotreatment to Reduce Risk in Oil-Impacted Soils

Research was conducted in six major focus areas: (1) Evaluation of the process using 6 test soils with full chemical and physical characteristics to determine controlling factors for biodegradation and chemical oxidation; (2) Determination of the sequestration time on chemical treatment suspectability; (3) Risk factors, i.e. toxicity after chemical and biological treatment; (4) Impact of chemical treatment (Fenton's Reagent) on the agents of biodegradation; (5) Description of a new genus and its type species that degrades hydrocarbons; and (6) Intermediates generate from Fenton's reagent treatment of various polynuclear aromatic hydrocarbons

Introducing administrative reform through the application of computer-based information systems: a case study in India

Administrative reform in a number of developing countries has recently been directed at achieving decentralization through the diffusion of information technology to local areas. However, despite these efforts, the main objective of improving the effectiveness of development planning and monitoring systems remains unfulfilled because of poor integration between the process of technology adoption and the context within which the technology is implemented. There is a paucity of literature that aims to make explicit the nature of this integration. This paper aims to offer a contribution in this direction by describing the case of the computerized rural information systems project (CRISP) in India. The results show that during the first few years of implementation information technology served to reinforce existing inefficiencies within the bureaucracy. Information technology was later used as a vehicle for promoting change within the administration as local administrators acquired the flexibility to direct the technology towards their own requirements