The binary oxide adsorbent using Fe and Mn (Fe-Mn) has been prepared by precipitation method to enhance the removal of phosphate. Different amounts of chitosan, a natural organic polymer, were used during preparation of Fe-Mn as a stabilizer to protect an aggregation of Fe-Mn particles. The optimal amount of chitosan has been determined considering the separation of the Fe-Mn particles by gravity from solution and highest removal efficiency of phosphate (Fe-Mn10). The application of Fe-Mn10 increased removal efficiency at least 15% compared to bare Fe-Mn. According to the Langmuir isotherm model, the maximum uptake (qm) and affinity coefficient (b) were calculated to be 184 and 240 mg/g, and 4.28 and 7.30 L/mg for Fe-Mn and Fe-Mn10, respectively, indicating 30% and 70% increase. The effect of pH showed that the removal efficiency of phosphate was decrease with increase of pH regardless of type of adsorbent. The enhanced removal efficiency for Fe-Mn10 was maintained in entire range of pH. In the kinetics, both adsorbents obtained 70% removal efficiency within 5 min and 90% removal efficiency was achieved at 1 h. Pseudo second order (PSO) kinetic model showed higher correlation of determination (R2), suggesting chemisorption was the primary phosphate adsorption for both Fe-Mn and Fe-Mn10.

Perfluorooctanoic acid(PFOA) was one of widely used per- and poly substances(PFAS) in the industrial field and its concentration in the surface and groundwater was found with relatively high concentration compared to other PFAS. Since various processes have been introduced to remove the PFOA, adsorption using GAC is well known as a useful and effective process in water and wastewater treatment. Surface modification for GAC was carried out using Cu and Fe to enhance the adsorption capacity and four different adsorbents, such as GAC-Cu, GAC-Fe, GAC-Cu(OH)2, GAC-Fe(OH)3 were prepared and compared with GAC. According to SEM-EDS, the increase of Cu or Fe was confirmed after surface modification and higher weight was observed for Cu and Fe hydroxide(GAC-Cu(OH)2 and GAC-Fe(OH)3, respectively). BET analysis showed that the surface modification reduced specific surface area and total pore volumes. The highest removal efficiency(71.4%) was obtained in GAC-Cu which is improved by 17.9% whereas the use of Fe showed lower removal efficiency compared to GAC. PFOA removal was decreased with increase of solution pH indicating electrostatic interaction governs at low pH and its effect was decreased when the point of zero charges(pzc) was negatively increased with an increase of pH. The enhanced removal of PFOA was clearly observed in solution pH 7, confirming the Cu in the surface of GAC plays a role on the PFOA adsorption. The maximum uptake was calculated as 257 and 345 μg/g for GAC and GAC-Cu using Langmuir isotherm. 40% and 80% of removal were accomplished within 1 h and 48 h. According to R2, only the linear pseudo-second-order(pso) kinetic model showed 0.98 whereas the others obtained less than 0.870.

The adsorption process using GAC is one of the most secured methods to remove of phosphate from solution. This study was conducted by impregnating Cu(II) to GAC(GAC-Cu) to enhance phosphate adsorption for GAC. In the preparation of GAC-Cu, increasing the concentration of Cu(II) increased the phosphate uptake, confirming the effect of Cu(II) on phosphate uptake. A pH experiment was conducted at pH 4-8 to investigate the effect of the solution pH. Decrease of phosphate removal efficiency was found with increase of pH for both adsorbents, but the reduction rate of GAC-Cu slowed, indicating electrostatic interaction and coordinating bonding were simultaneously involved in phosphate removal. The adsorption was analyzed by Langmuir and Freundlich isotherm to determine the maximum phosphate uptake(qm) and adsorption mechanism. According to correlation of determination(R2), Freundlich isotherm model showed a better fit than Langmuir isotherm model. Based on the negative values of qm, Langmuir adsorption constant(b), and the value of 1/n, phosphate adsorption was shown to be unfavorable and favorable for GAC and GAC-Cu, respectively. The attempt of the linearization of each isotherm obtained very poor R2. Batch kinetic tests verified that ~30% and ~90 phosphate adsorptions were completed within 1 h and 24 h, respectively. Pseudo second order(PSO) model showed more suitable than pseudo first order(PFO) because of higher R2. Regardless of type of kinetic model, GAC-Cu obtained higher constant of reaction(K) than GAC.

Chitosan, natural organic polymer, has been applied in water treatment as adsorbent due to non-toxic for human being. The amino group as functional group, can interacts with cation and anion at the same time. The prepared chitosan bead (HCB) was crosslinked to increase chemical stability (HCB-G) and both HCB and HCB-G were prepared to increase physical strength by drying referred to DCB and DCB-G, respectively. The adsorption effect for crosslinking and drying for four types of chitosan bead was tested using pseudo fist order (PFO), pseudo second order (PSO), and intraparticle diffusion model (ID). Regardless of PFO and PSO, the order of K, rate constant, is as followed: HCB > HCB-G > DCB > DCB-G for Cu(II) and phosphate. Drying leading to contraction of bead significantly reduced adsorption rate due to reduce the porosity of chitosan. In addition, crosslingking also negatively effect on adsorption rate. When compared with Cu(II) using hydrogel bead, phosphate showed higher value than Cu(II) for PFO and PSO. The application of ID showed that both hydrogel beads (HCB and HCB-G) obtained a very low R2 ranging to 0.37 to 0.81, while R2 can be obtained to over 0.9 for DCB and DCB-G, indicting ID is appropriate for low adsorption rate.

2 (Langmuir, Freundlich, Elovich, Temkin, and Dubinin-Radushkevich) and 3 (Sips and Redlich-Peterson)-parameter isotherm models were applied to evaluated for the applicability of adsorption of Cu(II) and/or phosphate isotherm using chitosan bead. Non-linear and linear isotherm adsorption were also compared on each parameter with coefficient of determination (R2). Among 2-parameter isotherms, non-linear Langmuir and Freundlich isotherm showed relatively higher R2 and appropriate maximum uptake (qm) than other isotherm equation although linear Dubinin-Radushkevich obtained highest R2. 3-parameter isotherm model demonstrated more reasonable and accuracy results than 2-parmeter isotherm in both non-linear and linear due to the addition of one parameter. The linearization for all of isotherm equation did not increase the applicability of adsorption models when error experiment data was included.

The physical treatment such as chemical precipitation or adsorption was usually added after biological treatment in wastewater treatment process since it was enforced to reduce the concentration of phosphate for wastewater effluent to 0.2 mg/L as P which was well known as one of main nutrient causing eutrophication in waterbody. Therefore, the new material functioned for both adsorption and disinfection was prepared with Fe and Cu, and TiO2, respectively, by changing the ratio of concentration referred to tri-metal (TM). According to SEM-EDS, TiO2 was 30~40% composition for any TM regardless of any synthesis condition. However, the ratio of composition for Fe and Cu was dependent on the initial Fe and Cu concentration, respectively. The removal efficiency of phosphate was obtained to 15% at low initial concentration and the maximum uptake (Q) was calculated to ~11 mg/g through Langmuir isotherm model using TM1 which was synthesized at 1000 mg/L, 1000 mg/L, and 2 g (10 g/L) for Fe(NO3)3, Cu(NO3)2, TiO2, respectively. In disinfection test, the efficiency of virus removal using TM was increased with increase of dosage of TM and can be reached 98% at 0.2 g.

Batch adsorption tests were performed to evaluate the applicability of adsorption kinetic model by using hydrogel chitosan bead crosslinked with glutaraldehyde (HCB-G) for Cu(II) as cation and/or phosphate as anion. Pseudo first and second order model were applied to determine the sorption kinetic property and intraparticle and Boyd equation were used to predict the diffusion of Cu(II) and phosphate at pore and boundary-layer, respectively. According to the value of theoretical and experimental uptake of Cu(II) and phosphate, pseudo second order is more suitable. On comparison with the value of adsorption rate constant (k), phosphate kinetic was 2-4 times faster than that of Cu(II) at any experimental condition indicating the electrostatic interaction between NH3 + and phosphate is dominated at the presence of single component. However, when Cu(II) and phosphate simultaneously exist, the value of k for phosphate was sharply decreased and then the difference was not significant. Both diffusion models confirmed that the sorption rate was controlled by film mass transfer at the beginning time (t < 3 hr) and pore diffusion at next time section (t > 6 hr).

Cu(II) can cause health problem for human being and phosphate is a key pollutant induces eutrophication in rivers and ponds. To remove of Cu(II) and phosphate from solution, chitosan as adsorbent was chosen and used as a form of hydrogel bead. Due to the chemical instability of hydrogel chitosan bead (HCB), the crosslinked HCB by glutaraldehyde (GA) was prepared (HCB-G). HCB-G maintained the spherical bead type at 1% HCl without a loss of chitosan. A variety of batch experiment tests were carried out to determine the removal efficiency (%), maximum uptake (Q, mg/g), and reaction rate. In the single presence of Cu(II) or phosphate, the removal efficiency was obtained to 17 and 16%, respectively. However, the removal efficiency of Cu(II) and phosphate was increased to 50~55% at a mixed solution. The maximum uptake (Q) for Cu(II) and phosphate was enhanced from 11.3 to74.4 mg/g and from 3.34 to 36.6 mg/g, respectively. While the reaction rate of Cu(II) and phosphate was almost finished within 24 and 6 h at single solution, it was not changed for Cu(II) but was retarded for phosphate at mixed solution.

가을철 수경재배에 알맞은 품종을 선발하기 위해 19개 품종을 대상으로 선발 실험을 하였고 그 중 가장 우수한 '아트라스'를 대상으로 생육 및 수량 실험을 수행하였다. 선발 실험결과 직립형태이면서 발아율 90%이상, 초장이 25cm 내외인 '아트라스'와 '딤플'이 가장 좋았고, 발아율은 다소 떨어지지만 '마호로바'도 비교적 우수한 생육을 보여 수출용 품종으로 적합하였고, 직립형태 중 초장이 20cm 정도인 '프리미엄'과 '플라톤' 품종은 내수용으로 적합한 품종으로 생각되었다. 정식시 재식거리를 12×9 cm, 12×11 cm, 12×13 cm, 12×15 cm로 하여 '아트라스'를 재배한 결과 초장 등 엽 생육은 처리간 유의성은 없었다. 재식거리에 따른 초장의 차이는 12×11 cm가 24.1 cm, 12×13 cm가 21.5cm, 12×15 cm가 21.2cm에 비해 재식거리가 넓어짐에 따라 감소되었다. 한편 지상부의 생체중은 재식거리가 넓어질수록 증가되었으며, 1개체의 무게는 12×9 cm의 7.3g에 비해 12×11 cm, 12×13 cm, 12×15 cm이 각각 10.7g으로 46% 컸으며, 정식 1홀당 생체중도 재식거리가 넓을수록 증가되어 12×9 cm의 20.2g에 비해 12×11 cm에서 33.8g, 12×13 cm에서 29.7g, 12×15 cm에서 26.9g으로 각각 67~33% 증가되어 수량에 영향을 미쳤다. 수량은 12×11 cm가 14,890kg·ha-1으로 12×9cm의 8,900kg·ha-1에 비해 67%증가되었다. 따라서 가을철 시금치 수경 재배시 안정 생산을 위한 재식거리는 12×11 cm라고 생각되어 진다.

This study was designed to analyze the possibility to enter the Chinese market aggressively by giving light on the factors which have effects on the continuous intention of Shanghai consumers to purchase environment-friendly foods, and the purchase of Korean environment-friendly foods. The objects of analysis were the 209 consumers living in Shanghai, China. As for the analysis method, the frequency, percentage, crossing analysis, χ²-test and logistic regression analysis were carried out, making use of SPSS PC+ 13.0. The study results are as follows. Firstly, it was identified that the decisive factors, such as good taste, health of family, freshness, food shop in a department store, international quality authentication, diversity of items and number of family members, had effects on the possibility that the consumers in Shanghai, China would purchase environmentfriendly foods continuously, showing the meaningful variables. Secondly, as for the decisive factors having effects on the possibility to buy Korean environmentfriendly foods continuously, it was identified that good taste, health of family, freshness and price cutting were the meaningful variables. Therefore, it is necessary that to set up a export promotion strategy to make the Shanghai consumers get interested in Korean environment-friendly foods and choose to buy the foods.

This study was examined to analyze of the characteristics analysis of purchasing behavior for environment-friendly agri-products on consumers in Gwangju. The 310 subjects formatted questionnaires were analyzed to frequency, percentage, crosstabulation, chi-square test and logistic regression by SPSS WIN 10.0. The main results of this study were as followings (1) It was analyzed that consumers have had the reason to purchase, purchase places, purchase number of times, purchase background, optimum price and purchase item for environment-friendly agri-products. (2) It was tended that consumer showed degree of satisfaction, point to improve and purchase intention continuously for environment-friendly agriproducts. (3) It was proved that age, income, medium contact level, cognitive level, valuation basis, producer and the direct deal, the consumer organization"s co-op, large-sized discount hoarded goods for purchase places and price reduction for promotion of purchase for environment-friendly agri-products was of the characteristics analysis.