The activated carbon was prepared from waste citrus peels using NaOH. With the increase of NaOH ratio, iodine adsorptivity and specific surface area of the activated carbon prepared were increased, but activation yield was decreased. The optimal condition of activation was at 300% NaOH and 700℃ for 1.5 hr. For the activated carbon produced under optimal condition, iodine adsorptivity was 1,006 mg/g, specific surface area was 1,356 m2/g, and average pore diameter was 20～25Å. From the adsorption experiment for benzene vapor in fixed bed reactor, it was found that the adsorption capacity of activated carbon prepared from waste citrus peel was higher than that of activated carbon purchased from Calgon company. This result implied that the activated carbon prepared from waste citrus peel could be used for gas phase adsorption.

Activated carbon was prepared from waste citrus peels by chemical activation with ZnCl2. The optimal condition of carbonization was at 300℃ for 1.5 hr. Activation experiments with carbonized samples prepared at optimal carboniztion condition were carried out under various conditions such as activation temperature of 400 to 900℃, activation time of 0.5 to 2.0 hr, and ZnCl2 ratio of 100 to 300%. In order to investigate the physical properties of the activated carbons prepared, iodine adsorptivities and specific surface areas were measured and their morphologies were observed from scanning electron microscopy. As ZnCl2 ratio increased, activation yield decreased, while iodine adsorptivity and specific surface area increased. The optimal condition of activation was at 300% ZnCl2 ratio and 300℃ for 1.5 hr, and then iodine adsorptivity and specific surface area was measured as about 862 mg/g and 756 m2/g, respectively. SEM photography showed that the surface morphology was changed and many active pore were produced by chemical activation.

This study compared the performance of a bioscrubber, a biofilter, and a combined system of bioscrubber and biofilter employed being operated at the laboratory-scale. for the removal of hydrogen sulfide. The bioscrubber maintained 100% removal of hydrogen sulfide up to inlet load of 56 g-S/m3․hr, while the removal efficiency was decreased with the increase of inlet load. The biofilter showed 100% removal efficiency up to inlet load of 126 g-S/m3․h and the maximum elimination capacity of 126 g S/m3․h for the inlet load of 224 g-S/m3․h. On the other hand, the combined system of bioscrubber and biofilter showed 100% removal for an inlet hydrogen sulfide load of up to 85 g-S/m3․h and the maximum elimination capacity of 153 g-S/m3․h for inlet loads of 224 g-S/m3․h.

The purpose of this work is to investigate the water quality change characteristics of treated water in water distribution systems of Water Treatment Plants (WTPs) of Jeju City. For this, the raw water, treated water and tap water that did not pass (named as not pass-tap water) and passed through the water storage tank (named as pass-tap water) were sampled and analyzed monthly from September 2001 to August 2002, for four (W, S, B and O) WTPs except for D WTP (where treated water is not supplied continuously) among WTPs of Jeju City. The concentrations of NO3- and Cl- of treated water in distribution systems changed little, but changed seasonally, which is considered to be based on the seasonal variation of the quality of raw water. The pH of treated water changed little in distribution systems for S WTP, but for the other WTPs, the pH of not pass-tap water was similar to that of treated water and the pH of pass-tap water was higher than that of treated water. The turbidity of treated water in distribution systems changed little except for W2 of W WTP and S4 and S5 of S WTP, where it was higher than that of each treated water. The residual chlorine concentrations between treated water and not pass-tap water changed little, but those between treated water and pass-tap water changed greatly, based on the its long residence time in water storage tank and so its reaction with organic matter, etc or its evaporation. The concentrations of TTHMs (total trihalomethanes) and CHCl3 that induce cancers in water distribution systems of these WTPs, were much lower than their water quality criteria and those in other cities. The concentrations of TTHMs of treated water and not pass-tap water were similar, but concentrations of pass-tap water were 1.5 to 2.0 times higher than those of treated water and not pass-tap water, due to the reaction of residual chlorine and organic matter, etc, with the result of long residence time in water storage tank.

The formation characteristics of trihalomethanes (THMs) and haloacetic acids (HAAs) were investigated in chlorination of raw water of different organic mallet characteristics. The samples used in this study were hydrophobic (N-HPO) and hydrophilic fraction (N-HPI) (which were concentrated and separated from Nakdong river water), and humic acid (HA) (which is known as a strong hydrophobic acid) as a reference organic matter, the specific UV absorbance (SUVA) of which was 2.19, 1.15 and 7.92, respectively. With increasing chlorine contact time, THMFP and HAAFP (the formation potential of THMs and HAAs) increased, but their increase was different depending on the organic mallet characteristics (i.e., for N-HPI, THMFP was higher than HAAFP, but the inverse result was obtained for N-HPO and HA and the ratio between them was greater for HA), and the mainly formed chemical species were CHCI3 in case of THMs and dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA) in case of HAAs for N-HPO and HA (and the ratios of CHCI3 to total THMs and DCAA and TCAA to total HAAs for HA were higher than those for N-HPO), but for N-HPI, the ratio of brominated THMs was a little higher than that of CHCI3 and the ratio of DCAA and TCAA to total HAAs was lower than that of N-HPO, although they are main chemical species in case of HAAs. Comparing THMFP and HAAFP with the increase in bromide concentration added with those in not adding it, the former increased greatly and its increase was higher for the organic mallet with stronger hydrophobicity, but the latter was lower for N-HPO and N-HPI and was similar for HA. The main chemical species with increasing bromide concentration were CHBt3 in case of THMs regardless of organic matter characteristics, and dibromoacetic acid (DBAA) for N-HPO and N-HPI, DBAA and tribromoacetic acid (TBAA) for HA in case of HAAs. With increasing reaction temperature and pH, THMFP and HAAFP increased for the former, but for the latter, THMFP increased and HAAFP decreased, although the rate of increase or decrease was different with organic mallet characteristics.

It was compared the reduction effect of contaminants and odor according to DO change and EM (effective microorganisms) addition in maturation process of piggery slurry. The maturation processes were divided into three cases as follows: R-1 was operated at 2.5 mg/ℓ of DO without the addition of EM, R-2 was operated at 7.5 mg/ℓ of DO without the addition of EM and R-3 was operated at 2.5 mg/ℓ of DO with the addition of EM. The addition of EM was more effective than the increase of DO for the reduction of CODcr, NH3-N and T-N in the maturation of piggery slurry. In addition, the reducing effect of odor intensity appeared high even in the short-term maturation period in case of adding EM and one could not even smell the stimulating odor of piggery slurry.

Sixteen soil samples around six areas (residental area, traffic area, power plant area, incineration area and factory area) where the stationary and mobile sources of polycyclic aromatic hydrocarbons (PAHs) are estimated to be emitted in Jeju City, were collected during Feburuary to March, 2004, and analyzed for 16 PAHs recommended by US EPA as primary pollutants to investigate their distribution characteristics. The concentrations of total PAHs (t-PAHs) and total carcinogenic PAHs (t−PAHCARC) in soils of Jeju City were in the range of 21.7∼264.2ng/g on a dry weight basis with a mean value of 87.2 ng/g and 6.3∼118.0ng/g with a mean value of 33.4 ng/g, respectively. The concentrations of t-PAHs were low in comparison with those in soils of other domestic and foreign countries. The mean concentrations of t-PAHs and (t−PAHCARC) with area decreased in the following sequences: traffic area> incineration area > factory area > power generation area > harbor area enli residental area. The correlation between t-PAHs and (t−PAHCARC) were very high (γ2=0.9701), indicating that (t−PAHCARC) concentration increases in proportion with t-PAHs. Comparing the distribution ratio of ring PAHs with area among 16 PAHs, it decreased in the order of 4-ring > 5-ring > 6-ring > 3-ring > 2-ring in all the areas except for harbor area. whitens for harbor area it was similar among 3-, 4- and 5-ring with high value. Low and no correlations between t-PAHs and soil compositions (organic matter content and particle size distribution) were observed, which is considered to be caused by the complex factors, such as the loading and characteristics of PAHs and diverse soil environment change, etc. From the examination of the three PAH origin indices, such as LMW/HMW (low molecular weight 2∼3 ring PAHs over high molecular weight 4∼6 ring PAHs), phenanthrene/anthracene ratio and fluoranthene/pyrene ratio, it can be concluded that the soil PAH contaminations were ascribed to strong pyrogenic origin in ail areas except for harbor area and to both pyrogenic and petrogenic origins.

The changes of contaminants and odor corresponding to anaerobic maturation process of piggery slurry were investigated by applying the additives, such as different kinds of complex microorganism products and deodorants containing microorganism activating agents. The pHs during 20-day anaerobic maturation were operated stably without great change regardless of the additives, although they were rather lower in the case that the additives were contained than the case that they were not contained. The effects of removing CODcr, NH3-N, T-N, and T-S in case that the additives were not contained, were not so great during the 20-day operation and so it would be difficult to remove the organic materials and nitrogen ingredients simply with anaerobic maturation process. However, in case of anaerobic maturation process that the additives were contained, their average removal rates were improved with the values of 49%, 63.5%, 48.5%, and 30.7% for above each of items, even if the 20-day of short-term maturation period was applied. Especially, odor intensity with the additives was lowered continuously during the operation period and it had more than two times of lowering effect compared to that without those.

Butyltin compounds (BTs), namely tributyltin (TBT), dibutyltin (DBT) and monobutyltin (MBT), were measured in surface and core sediments collected in 2001 inside Seogwipo Harbor, in order to evaluate their distribution characteristics. Seogwipo Harbor is one of major harbors of Jeju Island where a lot of shipping occurs and is designated as a trade port by the Korea Maritime and Port Law. BTs were detected in surface and core sediments of all stations and their concentrations in surface sediments were low, compared with to those in other sites of domestic and foreign countries. The main species among BTs was MBT, although there was a little difference with a survey site in surface sediments and in core sediments with depth. No or low correlations were obtained between organic matter or particles size of surface and core sediments and total BTs, indicating that these factors did not affect the distribution of BTs. It was estimated that more complex factors including BTs loads and surrounding sedimentary environments, affect the distribution of BTs. The high correlations between BTs indicated that DBT and MBT were mainly degraded from TBT based on antifouling paints of vessel etc. and other sources, such as DBT and MBT, could be ignored. The butyltin degradation indices ([DBT] + [MBT]/[TBT]) in surface sediments were in the range of 2.0～3.8 (mean 3.0), indicating that the parent compound, TBT, were inflowed into the surface sediments a long years ago, degraded and deposited. The sedimentation age of BTs contaminated core sediments could not estimated because the content of 210Pb activity were nearly all the same and so the sedimentation rate could not obtained.

The treatment of styrene vapor was carried out using the biofilter packed with loess/polyurethane composite during continuous operation of 74 days. The microorganisms were adapted within 2-3 days under the experimental conditions of inlet concentration and empty bed contact time (EBCT). At 200 sec of EBCT, the removal efficiency of styrene was 100% with 200 ppmv of inlet concentration, while 92% with 400 ppmv of inlet concentration. The biofilter showed the stable removal efficiencies of over 74 % under the EBCT range from 300 to 75 sec at the 150 ppmv of inlet styrene concentration. The maximum capacity of styrene removal for the biofilter packed with loess/polyurethane was 29 g/m3/hr. During continuous operation of 74 days, pH of the drain water changed slightly and the pressure drop through the biofilter column was below 45 mmH2O/m.

Starch was crosslinked with epichlorohydrin. Crosslinked starch-filled waterborne acrylate (CSWAC) films were prepared by blending this crosslinked starch with waterborne acrylate. The thermal and mechanical properties of these films were investigated by thermogravimetric analysis (TGA), tensile strength and elongation test. The biodegradability was also studied by determination of reduced sugar products after enzymatic hydrolysis and the surface morphology was investigated by scanning electron microscopy (SEM). The CSWAC film showed significantly higher tensile strength and elongation than those of starch-filled waterbonre acrylate (SWAC). The biodegradability of this film was higher than that of native starch-filled acrylate film, and was increased by the addition of crosslinked starch to the acrylate film.

Adsorption characteristics of toluene vapor, which is one of important source of volatile organic compounds (VOCs), by activated carbon were investigated using a fixed bed adsorption column. The operating parameters such as breakthrough curve, adsorption capacity, mass transfer zone (MTZ), and length of unused bed (LUB) were studied. The experimental results showed that the breakthrough time decreased with increasing inlet toluene concentration and gas flow rate. MTZ and LUB increased with the increase of inlet concentration, gas flow rate, and particle size of activated carbon. The adsorption capacity increased with the increase of inlet toluene concentration, while it decreased with increasing particle size. However, it was kept at constant value regardless of the increase of gas flow rate. Adsorption isotherm of toluene vapor could be represented by the Freundlich adsorption equation fairly well. From the adsorption experiments using some VOC gases such as toluene, xylene, butyl acetate. butanol and acetone, it was also found that the adsorption capacity was higher in the case of gas with higher boiling point and lower vapor pressure.

The starch-filled waterborne acrylate (SWAC) films were prepared. The structures and properties of SWAC films were investigated by infrared spectroscopy, thermogravimetric analysis, and strength test. The biodegradability of SWAC film was also studied by determination of reduced sugar products after enzymatic hydrolysis. The surface morphology of the SWAC film was investigated by scanning electron microscopy (SEM). The results showed that the tensile strength and elongation of SWAC film decreased with the increase of starch content. The SWAC film showed significantly higher water absorbed content than waterbonre acrylate film. The biodegradability of SWAC film increased as the content of starch increased. The biodegradation of starch in SWAC film by α-amylase was about 77% of that of pure starch.

The biodegradability of vinyl acetate acrylate resin and corn starch blend was studied by determination of the reduced sugars produced after enzymatic hydrolysis. The starch hydrolysis reaction by α-amylase was achieved within 5 minutes. Optimal ranges of temperature and pH for the starch hydrolysis by α-amylase were around 80 oC and 6.5-7.2, respectively. The biodegradability of the starch-filled acrylate films increased as the content of starch increased. The biodegradation of starch in the starch-filled acrylate film by α-amylase was about 48.6% of that of pure starch. This value of biodegradable starch-filled acrylate film gave a good result with enzymatic shortcut test. The surface morphologies of the starch-filled acrylate film after enzymatic hydrolysis were investigated by scanning electron microscopy (SEM).

A biofiltration system using activated carbon/polyurethane composite as solid support inoculated with Bacillus sp. was developed for treating a gaseous stream containing high concentrations of H2S. The effects of operating condition such as the influent H2S concentration and the empty bed contact time (EBCT) on the removal efficiency of H2S were investigated. The biofilter showed the stable removal efficiencies of over 99 % under the EBCT range from 15 to 60 sec at the 300 ppmv of H2S inlet concentration. When the inlet concentration of H2S was increased, the removal efficiencies decreased, reaching 95 and 74%, at EBCTs of 10 and 7.5 sec, respectively. The maximum elimination capacity in the biofilter packed with activated carbon/polyurethane composite media was 157 g/m3/hr.

The adsorption behaviors of strontium and cesium ions on fly ash, natural zeolites, and zeolites synthesized from fly ash were investigated. The zeolites synthesized from fly ash had greater adsorption capabilities for strontium and cesium ions than the original fly ash and natural zeolites. The maximum adsorption capacity of synthetic zeolite for strontium and cesium ions was 100 and 154 mg/g, respectively. It was found that the Freundlich isotherm model could fit the adsorption isotherm. The distribution coefficients (Kd) for strontium and cesium ions were also calculated from the adsorption isotherm data. The distribution coefficients decreased with increasing equilibrium concentration of strontium and cesium ions in solution. By studying the removal of cesium and strontium ions in the presence of calcium, magnesium, sodium, potassium, sulfate, nitrate, nitrite, and EDTA (in the range of 0.01 - 5 mM) it was found that these coexistence ions competed for the same adsorption sites with strontium and cesium ions.

Adsorption on goethite of individual component from a solution containing phosphate, sulfate, or copper ion was investigated. Competitive adsorption in the binary and ternary solution systems composed of phosphate, sulfate, and copper ions was also investigated. In competitive adsorption systems with phosphate and sulfate ions, the presence of phosphate ion reduced the adsorption of sulfate ion largely. On the other hand, the presence of sulfate ion caused only a small decrease in phosphate adsorption. This result suggests that phosphate ion is a stronger competitor for adsorption on goethite than sulfate ion, which is consistent with the higher affinity of phosphate for the surface compared to sulfate ion. Compared to the results from single-sorbate systems, adsorption of copper ion in the binary system of sulfate ion and copper ion was found to be enhanced in the presence of sulfate ion. Addition of sulfate ion to the binary system of copper ion and phosphate ion resulted in a small enhancement in copper sorption. This result implies that the presence of sulfate ion promotes adsorption of the ternary complex FeOHCuSO4. The adsorption isotherms could be well described by the Langmuir adsorption equation.

Adsorption of phosphate, sulfate, and copper ion to goethite was investigated. Goethite was prepared in the alkaline solution. In the single adsorbate systems, the final equilibrium plateau reached within 20 min. The adsorption isotherms of the individual ions could be well described by the Langmuir equation. The maximum adsorption capacities (qmax) were calculated as 0.483 mmol/g and 0.239 mmol/g at pH 3 for phosphate and sulfate ion, and 0.117 mmol/g at pH 6 for copper ion, respectively. In competitive adsorption system with phosphate and sulfate, phosphate ion was a stronger competitor for adsorption on goethite than sulfate ion, which was consistent with higher affinity of phosphate ion for the surface compared to sulfate ion. The existence of sulfate ion enhanced the adsorption of copper ion but the adsorption of sulfate was inhibited when copper ion was present.

Various kinds of zeolites, such as analcime (ANA), cancrinite (CAN), Na-P1 and sodalite octahydrate (SOD) could be synthesized from Hwangto by hydrothermal reaction in a high-pressure vessel. The adsorption characteristics of Cu(II) and Cd(II) by Hwangto and its synthetic zeolites were investigated using the chemical and electrochemical surface parameters of these adsorbents. The heavy metal adsorptivity among the adsorbents decreased in the following sequences: Na-P1>SOD>ANA>CAN>Hwangto. This sequence was the same with the values of surface site density (Ns) of these adsorbents and was correlated inversely with the values of pHpzc (pH of the point of zero charge) and the values of Ka2(int) (intrinsic surface deprotonation constant) of the adsorbents for synthetic zeolites, i.e., the adsorbents with higher values of Ns and with lower values of pHpzc and Ka2(int) for synthetic zeolites showed higher heavy metal adsorptivity. With increasing pH, the heavy metal adsorptivity increased greatly between pHpzc and pH 6 or 7 because of the steep increase of negatively charged sites for synthetic zeolites, but for Hwangto, it increased broadly because of slow increase of negatively charged sites based on its lower surface sites.

The photodegradations of pyrene, chrysene and benzo[a]pyrene that were similar in structure among polycyclic aromatic hydrocarbons (PAHs) were investigated with a low-pressure mercury lamp(the wavelength of 253.7 nm and UV output of 1.35x10-3 J/s). The optimum concentrations of TiO2 and H2O2 on the photodegradation of pyrene, chrysene and benzo[a]pyrene were 1 g/L and 1.5 x 10-3 M, respectively. By these optimum concentrations, their rates increased with increasing the concentration of TiO2 and H2O2 because the amounts of OH radical formed increased, but for the higher concentrations than the optimum, their rates decreased with increasing those concentrations because the white turbidity phenomena occurs in case of TiO2 and H2O2 acts as an OH radical inhibitor. The photodegradation rates among the photodegradation processes such as UV, UV/TiO2, UV/H2O2, and UV/H2O2/TiO2 decreased in the following sequences: UV/H2O2/TiO2> UV/H2O2> UV/TiO2> UV.