Earticle

Korea Highway Corporation has been introducing hi pass system that already is running to clear a habitual traffic jam and improve a service in advanced nation. This work investigates passage time of hi pass system usage and non usage vehicles on cheonggye, pankyo, and seongnam tollgate according to traffic, vehicles sort and delay time and quantitatively compute emission of air pollutants (CO, NOx, VOCs, TSP) and fuel consumption amount using COPERTⅢ model according to vehicles sorts. Reduction rate of emission on hi pass system usage vehicles appeared more about 50% than on general tollgate usage vehicles. If whole vehicles use the hi pass system, Reduction rate of emission about CO, NOx, VOCs, TSP, total air pollutants and fuel consumption amount showed 53%, 20%, 68%, 39%, 48% and 45% respectively.

The objective of this study is determine the proper dosage of waste activated carbon as the conditioning agent for dewaterability improvement of water treatment sludge and its to investigated the applicability for sludge reduction. The water treatment sludge was collected from thickening tank of C water treatment plant in U city. Also, the activated carbon was used the waste activated carbon discharged after wastewater treatment of B company in U city. The average total solid content of waste activated carbon and water treatment sludge were 2.0%(1.8~2.2%) and 87.9%, respectively. The optimum dosage of waste activated carbon for dewaterability improvement of water treatment sludge(500mL) was 5g. At optimum condition, the SRF(specific resistance) and TTF(Time to filter) of conditioned sludge were 5.1×1013m/kg and 633sec, respectively. Consequently, the waste activated carbon can be a recyclable material as a conditioning agent to improve the dewaterability of water treatment sludge.

The purpose of this study was to clarify the occurrence rate of care services and estimate the future demand and supply of those for the elderly in Mino City of Japan. The findings of this study were as follows; the occurrence rate of care services 11.1%, 2.5% at the occurrence rate of facilities services and occurrence rate of at-home services for the elderly 8.6%. These kinds of methods estimating the demand and supply of the care services can be applied to establish a preliminary framework for operating efficient future domestic care services market for the elderly.

In this study, we took advantage of a ultrasound technology, which has been gradually applied in environment industry nowadays, drew sewage sludge dissolution optimization through ultrasound to improve sewage sludge disintegration much better, and maximized alternative carbon source production required at denitrification process improvement of occurrence acidogenic fermentation. A series of bench-scale, semi-continuous acidogenic fermentation experiments, using sonicated sludge as a substrate, has been conducted to investigate the effects of ultrasound methods and HRT control on acidogenic fermentation. We could see the readily biodegradable COD from acidogenic fermentation after ultrasound considerably increase comparing with each control plot. Specifically, the increase was shown more than by 50%, 40% each. For the results of respirometry measurements used to estimate availability as substrate for microbial energy production activity, we figured out that content of readily biodegradable COD easily separable increased after sonication. Because the VFAs is created abundantly at anaerobic digestion step after ultrasound of sludge rather than before pretreatment, it could be replaced as alternative carbon source, which means an enormous amount of money saved.

The proposes of this study are to analyse the basic data relating to the management of solid waste, such as population and weather in Pusan city. The prospect of future trends and recyclable energy can be applied to the management of food waste and solid waste, and to suggest an effective dispose of waste materials in pusan city. For these, the investigation on the data and literatures, fields questionnaires has been performed.

In this research food waste and sewage sludge were dried using microwave oven. The drying characteristics and reasonable mixing ratio of food waste and sewage sludge for the effect of physical factor such as moisture contents, drying rate and calorific value. The drying characteristic of microwave oven were evaluated and compared. Sewage sludge was collected in S wastewater treatment plant and food waste was collected in D university restaurant. Microwave oven with 2,450MHz frequency and 700W power is household appliances. When moisture contents of food waste and sludge cake reached 40%, drying time was 4 minute at microwave intensity of 700W. When food waste and dewatered sludge were dried using microwave oven, moisture contents of food waste and dewatered cake were 21.9% and 21.4%, respectively. And these results were higher than mixed sample. It showed that dried mixed sample improved the drying characteristics. The calorific value of food waste and dewatered sludge was 5,788.9cal/g and 3,021.3cal/g at microwave intensity of 700W. The calorific value of mixed materials was higher than dewatered sludge. From this facts, it confirmed that mixed material of food waste and sewage sludge will improve the efficiency of incineration and decrease the auxiliary fuel.