• KSBB Journal
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• v.20 no.6
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• pp.393-400
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• 2005

Hydrogen($H_2$) as a clean, and renewable energy carrier will be served an important role in the future energy economy. Several biological $H_2$ production processes are known and currently under development, ranging from direct bio-photolysis of water by green algae, indirect bio-photolysis by cyanobacteria including the separated two stage photolysis using the combination of green algae and photosynthetic microorganisms or green algae alone, dark anaerobic fermentation by fermentative bacteria, photo-fermentation by purple bacteria, and water gas shift reaction by photosynthetic or fermentative bacteria. In this paper, biological $H_2$ production processes, that are being explored in fundamental and applied research, are reviewed.

• Environmental Engineering Research
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• v.23 no.1
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• pp.46-53
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• 2018

This study explores the environmentally innovative and low-impact technology, a zero food waste system (ZFWS) that utilizes food waste and converts it into composts or biofuels and curtails carbon emissions. The ZFWS not just achieves food waste reductions but recycles food waste into fertilizer. Based on a fermentation-extinction technique using bio wood chips, the ZFWS was employed in a field experiment of the system installed in a large-scale apartment complex, and the performance of the system was examined. The on-site ZFWS consisted of three primary parts: 1) a food waste slot into which food waste was injected; 2) a fermentation-extinction reactor where food waste was mixed with bio wood chips made up of complex enzyme and aseptic wood chips; and 3) deodorization equipment in which an ultraviolet and ozone photolysis method was employed. The field experiment showed that food waste injected into the ZFWS was reduced by 94%. Overall microbial activity of the food waste in the fermentation-extinction reactor was measured using adenosine tri-phosphate (ATP), and the degradation rate of organic compounds, referred to as volatile solids, increased with ATP concentration. The by-products generated from ZFWS comply with the national standard for organic fertilizer.

• Vacuum Magazine
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• v.2 no.4
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• pp.9-15
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• 2015

Nonthermal bio-compatible plasma (bioplasma) sources and their characteristics operating at atmospheric pressure could be used for biological cell interactions, especially for plasma bioscience and medicines. The electron temperatures and plasma densities of this bioplasma are measured to be 0.7 ~ 1.8 eV and $(3-5){\times}10^{14-15}cm^{-3}$, respectively. Herein, we introduced general schematic view of the plasma-initiated ultraviolet photolysis of water inside the biological solutions or living tissue for the essential generation mechanism of the reactive hydroxyl radical [OH] and hydrogen peroxide [$H_2O_2$], which may result in apoptotic cell death in plasma bioscience and medicines. Further, we surveyed the various nonthermal bioplasma sources including plasma jet, micro-DBD (dielectric barrier discharge) and nanosecond discharged plasma. The diseased biological protein, cancer, and mutated cells could be treated by these bioplasma sources or bioplasma activated water to result in their apoptosis for new paradigm of plasma bioscience and medicines.

• Journal of Electrochemical Science and Technology
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• v.7 no.4
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• pp.316-326
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• 2016

Development and discovery of efficient, cost-effective, and robust electrocatalysts are imperative for practical and widespread implementation of water electrolysis and fuel cell techniques in the anticipated hydrogen economy. The electrochemical reactions involved in water electrolysis, i.e., hydrogen and oxygen evolution reactions, are complex inner-sphere reactions with slow multi-electron transfer kinetics. To develop active electrocatalysts for water electrolysis, the physicochemical properties of the electrode surfaces in electrolyte solutions should be investigated and understood in detail. When electrocatalysis is conducted using nanoparticles with large surface areas and active surface states, analytical techniques with sub-nanometer resolution are required, along with material development. Scanning electrochemical microscopy (SECM) is an electrochemical technique for studying the surface reactions and properties of various types of electrodes using a very small tip electrode. Recently, the morphological and chemical characteristics of single nanoparticles and bio-enzymes for catalytic reactions were studied with nanometer resolution by combining SECM with atomic force microscopy (AFM). Herein, SECM techniques are briefly reviewed, including the AFM-SECM technique, to facilitate further development and discovery of highly active, cost-effective, and robust electrode materials for efficient electrolysis and photolysis.