Biochemical technology for the detoxification of geothermal brines and the recovery of trace metals

Studies conducted at BNL, have shown that a cost-efficient and environmentally acceptable biochemical technology for detoxification of geothermal sludges is most satisfactory, as well as technically achievable. This technology is based on biochemical reactions by which certain extremophilic microorganisms interact with inorganic matrices of geothermal origin. The biochemical treatment of wastes generated by power plants using geothermal energy is a versatile technology adaptable to several applications beyond that of rendering hazardous and/or mixed wastes to non-hazardous by products, which meet regulatory requirements. This technology may be used for solubilization or recovery of a few metals to the isolation of many metals including radionuclides. In the metal recovery mode, an aqueous phase is generated which meets regulatory standards. The resulting concentrate contains valuable trace metals and salts which can be further converted into income generating products which can off-set the initial investment costs associated with the new biotechnology. In this paper, recent developments in this emerging technology will be discussed

Recent advances in biochemical technology for the processing of geothermal byproducts

Laboratory studies has shown the biochemical technology for treating brines/sludges generated in geothermal electric powerproduction to be promising, cost-efficient, and environmentally acceptable. For scaled-up field use, the new technology depends on the chemistry of the geothermal resources which influences choice of plant design and operating strategy. Latter has to be adaptable to high/low salinity, temperatures, quantity to be processed, and chemistry of brines and byproducts. These variables are of critical and economic importance in areas such as the Geysers and Salton Sea. The brines/sludges can also be converted into useful products. In a joint effort between industrial collaborators and BNL, several engineered processes for treating secondary and other byproducts from geothermal power production are being tested. In terms of field applications, there are several options. Some of these options are presented and discussed

The Bulk RS KK-gluon at the LHC

We study the possibility of discovering and measuring the properties of the lightest Kaluza-Klein excitation of the gluon in a Randall-Sundrum scenario where the Standard Model matter and gauge fields propagate in the bulk. The KK-gluon decays primarily into top quarks. We discuss how to use the $t \bar{t}$ final states to discover and probe the properties of the KK-gluon. Identification of highly energetic tops is crucial for this analysis. We show that conventional identification methods relying on well separated decay products will not work for heavy resonances but suggest alternative methods for top identification for energetic tops. We find, conservatively, that resonances with masses less than 5 TeV can be discovered if the algorithm to identify high $p_T$ tops can reject the QCD background by a factor of 10. We also find that for similar or lighter masses the spin can be determined and for lighter masses the chirality of the coupling to $t\bar t$ can be measured. Since the energetic top pair final state is a generic signature for a large class of new physics as the top quark presumably couples most strongly to the electroweak symmetry breaking sector, the methods we have outlined to study the properties of the KK-gluon should also be important in other scenarios.Comment: 21 pages, 13 figure

Geothermal brines and sludges: a new resource

Development of cost efficient biochemical processes for the treatment of geothermal brines and sludges is the main thrust of a major R&D effort at Brookhaven National Laboratory (BNL). This effort has led to the design of an environmentally acceptable, technically and economically feasible new technology which converts geothermal wastes into products with significant commercial potential. These include valuable metals recovery with a metal extraction and recovery efficiency of better then 80% over short periods of time (5-25 hours). The new technology also yields valuable salts, such as potassium chloride and generates high quality pigment free silica. The basic technology is versatile and can, with slight modifications, be used in the treatment of hypersaline as well as low salinity brines and sludges. Concurrently traces of toxic metals, including radium are removed to levels which are within regulatory limits. The current status of the new biochemical technology will be discussed in this paper

Environmental significance of biocatalytic conversion of low grade oils

Studies dealing with the interactions between extremophilic microorganisms and crude oils have led to the identification of biocatalysts which through multiple biochemical reactions catalyze desulfurization, denitrogenation, and demetalation reactions in oils. Concurrently, the oils are also converted to lighter oils. These complex biochemical reactions have served as models in the development of the crude oil bioconversion technology to be applied prior to the treatment of oils by conventional chemical processes. In practical terms, this means that the efficiency of the existing technology is being enhanced. For example, the recently introduced additional regulation for the emission of nitrogen oxides in some states restricts further the kinds of oils that may be used in burners. The biocatalysts being developed in this laboratory selectively interact with nitrogen compounds, i.e. basic and neutral types present in the oil and, hence, affect the fuel NOx production. This, in turn, has a cost-efficient influence on the processed oils and their consumption. In this paper, these cost-efficient and beneficial effects will be discussed in terms of produced oils, the lowering of sulfur and nitrogen contents, and the effect on products, as well as the longevity of catalysts due to the removal of heteroatoms and metal containing compounds found in crudes

The use of chemical markers in the evaluation of crude oil bioconversion products, technology, and economic analysis

Experimental data gathered over the past several years show that the interactions of microorganisms with crude oils are variable and depend on the microbial species and the chemical composition of crude oils. Systematic studies of chemical mechanisms by which selected microorganisms react with crude oils have led to the identification of biochemical markers characteristic of the interactions of microbes with oils. These biomarkers belong to several groups of natural products ranging from saturate and polyaromatic hydrocarbons containing heterocyclics to organometallic compounds. Chemical marker analyses indicate that the interaction of microbes with crude oils involves multiple chemical reactions resulting from the biochemical interactions between microbes and oils. Different interactions may influence the efficiency of processes in which single or mixed microbial species are used for the oil treatment and may also suggest possible combinations of biological and chemical technologies. Further, the biochemical conversions of oils can be monitored by these chemical markers, which is particularly useful in the optimization of biochemical processing, cost efficiency, and engineering studies. Recent results from these studies are discussed

Increasing Incidence of Clostridium difficile-associated Disease, Singapore

10.3201/eid1409.070043Emerging Infectious Diseases1491487-148

Supersymmetry and the positron excess in cosmic rays

Recently the HEAT balloon experiment has confirmed an excess of high-energy positrons in cosmic rays. They could come from annihilation of dark matter in the galactic halo. We discuss expectations for the positron signal in cosmic rays from the lightest superpartner. The simplest interpretations are incompatible with the size and shape of the excess if the relic LSPs evolved from thermal equilbrium. Non-thermal histories can describe a sufficient positron rate. Reproducing the energy spectrum is more challenging, but perhaps possible. The resulting light superpartner spectrum is compatible with collider physics, the muon anomalous magnetic moment, Z-pole electroweak data, and other dark matter searches.Comment: 4 pages, 2 figures, references added, minor wording change

Operation and control design of an input-series-input-parallel-output-series conversion scheme for offshore DC wind systems

High-power converters for high-voltage direct current transmission systems and collecting networks are attracting increasing interest for application in large offshore wind farms. Offshore wind farms are capable of generating more electric energy at lower cost when compared with onshore wind systems. In this study, DC/DC voltage conversion should be achieved with a power converter that uses readily available semiconductor devices. A modular DC/DC converter can achieve the required system currents and voltages without exceeding semiconductor ratings. In this study, the operation and control strategy for an input-series–input-parallel–output-series (ISIPOS) energy conversion system for wind systems are presented. The ISIPOS system allows the direct connection of wind turbines to the DC grid. In this research, the design process to control the input and output currents and voltages is explained. In addition, a new method to ensure voltage and current sharing between the different modules is presented and explained. The basic structure, control design, and system performance are tested using MATLAB/SIMULINK. Practical results validate the control design flexibility of the ISIPOS topology when controlled by a TMSF280335 DSP