Particle collection efficiency and air cleaning capacity were tested for the two-stage electrostatic precipitator for use in indoor air cleaning systems. A wire-plate type ionizer was used as a particle charger and a dielectric film consisted of polypropylene (or polyethylene) coated metals and zigzagged metal electrodes was used as a particle collector in the electrostatic precipitator. Both particle collection efficiency and air cleaning capacity increased as increasing the applied voltage on the charger and the collector, and furthermore, as increasing the collector film width (i.e. collection area). Air cleaning capacities estimated by the product of particle collection efficiency and air flow rate were quite well consistent with the experimental ones with a proportional constant of 0.964. Ozone concentrations emitted from the charger at the applied voltages of 5.0 and 5.2 kV were less than 0.05 ppm, indoor ozone standards of UL 867-2002, KS C 9314 and SPS-KACA002-132. For the air flow rate of 11.7 m³/min, the applied floor area of 48.2 m² could be obtained when 5.2 kV and 6.0 kV were applied on the ionizer and the collector, respectively and the collector of two 15 mm polyethylene dielectric films was used.

Spent coffee grounds, activated sludge, chicken manure, and agricultural waste-derived biochar were used to manufacture eco-friendly and functional compost via the bioaugmentation of white rot fungus and plant growth that promotes beneficial microorganisms. Six lab-scale composting reactors were established to perform composting. After composting was completed over 45 days, the composts were analyzed for major elements, physico-chemical characteristics, compost maturity, and compost effectiveness on crop growth and quality. Concentrations of T-N and PO4 3− significantly increased in the composts that had been amended with biochar and/or white rot fungus compared to the control, while those of NO3 −-N, TOC and TOC/T-N had significantly decreased, indicating the occurrence of effective composting. Besides, the germination indices of these composts were also generally higher than the control by 10-34%, indicating that the composts were mature. The four composts amended with biochar and/or white rot fungus (TR-3, TR- 4, TR-5, TR-6) also appeared to stimulate more growth in lettuce compared to commercial organic fertilizers (by 36- 104%). Besides, composts TR-3 and TR-4 respectively enhanced DPPH scavenging activity in lettuce leaves by 58% and 49%, while TR-4 and TR-5 respectively enhanced the total phenolic content (TPC) by 44% and 37%. This implies that the amendment of biochar and the bioaugmentation of white rot fungus could facilitate the composting process for the production of quality functional compost that is able to enhance the antioxidant content in crops. Quality composts could better compete with the commercially available fertilizers in the market, leading to the eco-friendly recycling of organic wastes such as spent coffee grounds, sludge, chicken manure, and agricultural waste.

Recycling of food wastes was tried based on fermenting and composting food wastes using a microbial consortium. Manufactured compost (using 11.3% food waste) turned out to be effective in increasing soil fertility and crop growth (radish; Raphanus sativus). More specifically, the treatment of the composted food wastes enabled a stimulated growth of radish leaves by 80% and an increased uptake of δ15NAIR by 250% compared with a commercial organic compost. Moreover, the compost derived from the wastes appeared to allow a sustainable management of nitrogen fertilizer compared with the chemical fertilizer, minimizing nitrogen pollution. The microbial community analysis showed significant difference in the microbial community pattern in soil treated with the composted food wastes relative to soil treated with a commercial organic fertilizer or a chemical fertilizer. The results may indicate that the wastes processed by the consortium could result in an efficient recycling of the nuisance materials such as food wastes and other organic solid wastes.

본 연구에서는 크루즈선에서 발생하는 오 폐수의 고도처리를 위하여 SBR공정에 유효미생물을 주입하는 변법을 이용하여 실험실 규모의 실험을 수행하였다. 질소 인의 고도 처리 효율과 크루즈선이라는 특수 환경과의 접목성을 검토한 결과 SBR공정에 유효미생물을 주입하는 변법은 선박환경에 매우 적합한 것으로 평가되었다. 또한 기존의 활성슬러지에 유효미생물의 주입함으로써 슬러지 팽화 등의 문제를 해결할 수 있어 슬러지의 안정성을 확보할 수 있었으며, 미생물 관찰 결과 고도처리에 유리한 미생물종의 출현으로 질소 인의 처리 효율이 높아지는 것을 확인할 수 있었다. 이로 인해 총질소와 인의 제거 효율은 74%, 75%로 나타났으며 이러한 결과로 미루어 강화되어가는 해양오염기준을 충만족시킬 수 있을 공정으로 판단된다.