최근 국내는 이상기후에 따른 극심한 폭염이 지속되고 있으며, 잦은 국지성 호우로 인한 도로 공용수명을 현저히 단축시키고 있다. 국지성 호우 시, 도로 위 유수량의 급격한 증가는 도로 포장체 내 균열, 공극, 신축이음부를 통한 수분 침투를 가속화 한다. 이와 더불 어, 중차량의 교통하중이 반복적으로 지속 될 경우, 포장체 내부의 골재-바인더 간 결합력이 저하되어, 포트홀, 소성변형, 골재비산 등 의 포장 파손을 야기한다. 국내의 일반국도 및 고속도로에서는 아스팔트 노면 위 포트홀, 함몰, 국부적 균열 등의 파손이 발생 시, 일반적으로 파손부를 절삭 · 제거하고, 상온 또는 가열, 중온 아스팔트 혼합물로 유지보수를 수행한다. 하지만 파손부에 임시방편으로 긴급 보수재를 사용할 경우, 지속적인 강우와 차량의 교통하중으로 인해 골재와 바인더 간 결합력을 약화시키고, 신·구 포장 경계면의 부착강도가 저하되어 보수 부위가 쉽게 파손되는 문제가 발생하고 있다. 이는 고속 주행 차량의 안전을 심각하게 위협하는 요인으로 작용한다. 본 연구에서는 방수 · 부착성이 우수한 과립형 구스 매스틱 아스팔트 혼합물(Granular Guss Mastic Asphalt Mixture, 이하 GGM-AM) 을 이용해 소파 보수재료서의 적용성을 검토하기 위해 내구성능에 대한 실내 기초물성실험 결과를 비교 · 분석하였다.

최근 국내는 이상기후에 따른 극심한 폭염이 지속되고 있으며, 잦은 국지성 호우로 인한 도로 공용수명을 현저히 단축시키고 있다. 국지성 호우 시, 도로 위 유수량의 급격한 증가는 도로 포장체 내 균열, 공극, 신축이음부를 통한 수분 침투를 가속화 한다. 이와 더불 어, 중차량의 교통하중이 반복적으로 지속 될 경우, 포장체 내부의 골재-바인더 간 결합력이 저하되어, 포트홀, 소성변형, 골재비산 등 의 포장 파손을 야기한다. 국내의 일반국도 및 고속도로에서는 아스팔트 노면 위 포트홀, 함몰, 국부적 균열 등의 파손이 발생 시, 일반적으로 파손부를 절삭 · 제거하고, 상온 또는 가열, 중온 아스팔트 혼합물로 유지보수를 수행한다. 하지만 파손부에 임시방편으로 긴급 보수재를 사용할 경우, 지속적인 강우와 차량의 교통하중으로 인해 골재와 바인더 간 결합력을 약화시키고, 신·구 포장 경계면의 부착강도가 저하되어 보수 부위가 쉽게 파손되는 문제가 발생하고 있다. 이는 고속 주행 차량의 안전을 심각하게 위협하는 요인으로 작용한다. 본 연구에서는 방수 · 부착성이 우수한 과립형 구스 매스틱 아스팔트 혼합물(Granular Guss Mastic Asphalt Mixture, 이하 GGM-AM) 을 이용해 소파 보수재료서의 적용성을 검토하기 위해 내구성능에 대한 실내 기초물성실험 결과를 비교 · 분석하였다.

In this paper, the adsorption removal characteristic for 10 species of perfluoroalkyl and polyfluoroalkyl substances (PFAS) was investigated using GAC and modified GAC (GAC-Cu). After modification with Cu(II), the amount of copper was to 1.93 and 4.73 mg/g for GAC and GAC-Cu, respectively. The total amount of 10 species of PFAS per specific area was obtained to 0.548 and 0.612 ng/m2 for GAC and GAC-Cu, respectively. A series of batch test confirmed lower efficiency was observed with a smaller number of carbon chain length and the removal efficiency of PFCA (perfluoroalkyl carboxylic acids) was lower than that of PFSA (perfluoroalkyl sulfonic acids) with the same carbon chain length. Regarding the pH effect, the adsorption capacity was decreased with increase of pH due to the increase of electrostatic repulsion. According to pseudo first and second order (PFO and PSO) kinetic models, while the values of equilibrium uptake and time did not show significant difference, a difference in uptake was observed between 24-48h. Furthermore, based on correlation analysis, Log Kow and uptake have a high correlation with molecular weight (M.W.) and initial concentration, respectively. These results show that long-chain PFAS have higher removal efficiency due to their increased hydrophobicity.

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.

Melons, a rich source of vitamins and fibers, are commonly grown in the soil. Hydroponic cultivation could improve yield and quality of melon and selection of substrate volume and the kind of substrates is important for hydroponic cultivation of melons. This study investigated the effect on melon growth according to volume of granular rockwool and substrates of coir and rockwool slab. ‘Geumsegye’ melon (Cucumis melo L. cv. Geumsegye) was cultivated hydroponically according to volume of granular rockwool to 1.0, 1.5, 2.0, 3.0, and 4.0 L, and was also cultivated using coir and rockwool slabs. Logistic model was applied to estimate the growth characteristics of melons such as plant height, leaf length, leaf width, and the characteristics of fruit. The growth characteristics of melons were significantly increased at 4.0 L compared to those grown of 1.0 L volume of on granular rockwool, and the results were the highest in coir and rockwool slabs. Melons grown in rockwool slabs showed the largest fruit fresh weight, fruit length, and fruit width. During hydroponic cultivation, growth characteristics of melon appropriate at the 4.0 L volume of granular rockwool, and the highest at coir and rockwool slabs. This study provides a basis for understanding the effect of root zone environment to the growth characteristics and fruit quality of non-netted melon.

There is a need for the purification of indoor air owing to a high rate of pollution in today’s world. For this, cabin air filters (CAFs) are widely used, which requires the addition of certain adsorbents to increase the volatile organic compound (VOC) removal efficiency. However, this addition causes high-pressure resistance, which may hamper commercial applications by requiring more energy and negatively affecting fresh air delivery rate. Hence, in this study, a high-performance combined CAF (CCAF) with excellent dust and chemical filtration performance and low differential pressure was prepared using granular activated carbon (GAC)/activated carbon fiber (ACF) mixed medium. The GAC/ACF mixed medium had higher air permeability than the ACF medium of the same weight, and it exhibited similar ultrafine dust filtration performance to the ACF medium without an increase in differential pressure. In addition, the GAC/ACF mixed medium showed excellent gas removal performance without increasing differential pressure by combining the VOC removal characteristics of the GAC and ACF filter media. The improved VOC removal performance of the GAC/ACF mixed medium was due to the hybrid effect of the hierarchical pore structures of the GAC and the nearly uniform pore structures of the ACF, which resulted in a slow and increased gas adsorption by the GAC and rapid gas adsorption of the ACF.

The activity of anaerobic ammonium oxidation (ANAMMOX) immobilized in synthetic media (Poly Ethylene Glycol, PEG) and granular form was evaluated comparatively to investigate the effect of influent nitrogen concentration and exposure of oxygen. In ANAMMOX granule reactor, when concentration of influent total nitrogen increased to 500mg/L, removal efficiency of ammonium, nitrite and nitrate were shown to 90.5±6.5, 96.6±4.9, and 93.2±6.1%, respectively. In the case of the PEG gel, it showed lower nitrogen removal performance, resulting in that the removal efficiency of ammonium, nitrite and nitrate were shown to 83.3±13.0, 96.4±6.1, and 90.3±7.5%, respectively. In second step, when exposed to oxygen, the nitrogen removal performance in the ANAMMOX granule reactor also remained stable, but the activity of PEG gel ANAMMOX was found to be inhibited. Consequently, the PEG gel ANAMMOX was a higher sensitivity than that of granular ANAMMOX with two variables applied in this study.

The algal blooms in stagnant streams and lakes have caused many problems. Excessive algae leads to disturbance of ecosystem and overload of water treatment processes. Therefore, phosphorus(P), source of algal blooms, should be controlled. In this study, a filtration trench has been developed to convert dissolved phosphorus into hydroxyapatite(HAP) so that it could be crystallized on the surface of ‘phosphorus removal granular material’; and residual particulate phosphorus could be removed by additional precipitation and filtration. The front and rear parts of filtration trench consisted of ‘phosphorus removal granular material contact bed’ and ‘limestone filtration bed’, respectively. As a result of the column test using phosphorus removal granular material and limestone serially, PO4-P was removed more than 90% when EBCT(empty bed contact time) of the contact bed was over 20 minutes; and T-P represented 60% of removal efficiency when total EBCT was over 1.5 hours. The results of column tests to figure out the sedimentation characteristics showed that more than 90% of particulate phosphorus could be removed within 24 hours. It was necessary to optimize the filtration part in order to increase removal efficiency of T-P additionally. Also, it was confirmed through the simulation of Visual MINTEQ that most of particulate phosphorus in the column tests is the form of HAP. Based on the results of the study, it could be suggested that the design parameters are over 0.5 hour of EBCT for phosphorus removal granular material contact bed and over 1.5 hours of EBCT for limestone filtration bed.

Prussian blue is known as a superior material for selective adsorption of radioactive cesium ions; however, the separation of Prussian blue from aqueous suspension, due to particle size of around several tens of nanometers, is a hurdle that must be overcome. Therefore, this study aims to develop granule type adsorbent material containing Prussian blue in order to selectively adsorb and remove radioactive cesium in water. The surface of granular activated carbon was grafted using a covalent organic polymer (COP-19) in order to enhance Prussian blue immobilization. To maximize the degree of immobilization and minimize subsequent detachment of Prussian blue, several immobilization pathways were evaluated. As a result, the highest cesium adsorption performance was achieved when Prussian blue was synthesized in-situ without solid-liquid separation step during synthesis. The sample obtained under optimal conditions was further analyzed by scanning electron microscope-energy dispersive spectrometry, and it was confirmed that Prussian blue, which is about 9.7% of the total weight, was fixed on the surface of the activated carbon; this level of fixing represented a two-fold improvement compared to before COP-19 modification. In addition, an elution test was carried out to evaluate the stability of Prussian blue. Leaching of Prussian blue and cesium decreased by 1/2 and 1/3, respectively, compared to those levels before modification, showing increased stability due to COP-19 grafting. The Prussian blue based adsorbent material developed in this study is expected to be useful as a decontamination material to mitigate the release of radioactive materials.

실 산성 도금폐수를 입상활성탄(GAC)이 유동메디아로 첨가된 유동상 멤브레인 반응기를 이용하여 처리하였다. GAC 유동조건에서 적용 투과플럭스에 대해 시간에 따른 흡입압의 증가는 관찰되지 않았다. 폐수의 중성 pH에서 파울링 속도는 산성 조건에 비해 GAC 유동조건에서 크게 감소하였다. 해당 폐수의 용액 pH 증가는 입자크기의 증가를 가져왔고 이는 멤브레인 표면에서 상대적으로 성긴 구조의 케이크층 형성을 야기시켰다. 유동상 멤브레인 반응기에서 GAC 유동 하에 95% 이상의 COD 제거율이 관찰되었으며 총부유물질은 거의 완벽하게 제거되었다. 실 도금폐수의 pH에서, 유동상 멤브레인 반응기의 구리 및 크롬의 제거는 거의 관찰 되지 않았다. 그러나 pH를 중성으로 증가 시켰을 시 구리와 크롬의 제거율은 각각 99%와 94%까지 증가를 하였다. 적용해 준 pH에 상관 없이, 시안의 경우 95% 이상의 제거율을 달성하였다. 이는 유기물과 시안 착물 형성으로 인해 유동상 멤브레인 반응기 내 GAC의 강한 흡착으로 제거된 것으로 사료된다.

One of the major sources causing eutrophication and algal blooms of lakes or streams is phosphorus which comes from point and nonpoint pollution sources. HAP (hydroxyapatite) crystallization using granular alkaline materials can achieve the decrease of phosphorus load from wastewater treatment plants and nonpoint pollution control facilities. In order to induce HAP crystal formation, continuous supply of calcium and hydroxyl ions is required. In this research, considering HAP crystallization, several types of lime-based granular alkaline materials were prepared, and the elution characteristics of calcium and hydroxyl ions of each were analyzed. Also, column tests were performed to verify phosphorus removal efficiencies of granular alkaline materials. Material_1 (gypsum+cement mixed material) achieved the highest pH values in the column tests consistently, also, Material_2 (gypsum+slag mixed material) and Material_3 (calcined limestone material) achieved over pH 9.0 for 240 hours (10 days) and proved the efficiencies of long-term ion supplier for HAP crystallization. In the column tests using Material_3, considerable pH increase and phosphorus removal were carried out according to each linear velocity and filtration depth. T-P removal efficiencies were 87.0, 84.0, 68.0% and those of PO4-P 100.0, 97.0, 80.0% for linear velocity of 1.0, 2.5, 5.0 m/hr respectively. Based on the column test results, the applicability of phosphorus removal processes for small-scale wastewater treatment plants and nonpoint pollution control facilities was found out.

고강도, 내약품성, 무독성, 내연소성의 장점을 가지고 있는 PVdF (polyvinylidene fluoride) 나노섬유로 기공이 0.4 μm 평막을 제조한 후, 부직포와 평막으로 나권형 모듈을 제작하였다. 용존유기물의 흡착 제거를 위한 입상 활성탄(GAC, granular activated carbon) 흡착 컬럼과 자체 제작한 나권형 모듈로 혼성 수처리 공정을 구성하였다. 카올린과 휴믹산으로 조 제한 모사 용액을 대상으로, 처리수를 재순환하는 경우와 배출하는 경우 각각 GAC 충진량의 영향을 알아보았다. 여과실험 후 물 역세를 하여 회복률과 여과저항을 계산하였다. 또한, 탁도와 UV254 흡광도를 측정하여 GAC의 흡착 효과를 고찰하였 다. 그 결과, 처리수를 재순환하는 경우와 배출하는 경우 모두 탁도 처리율에는 GAC 충진량의 영향이 없었다, 하지만 GAC 의 UV254 흡광도 처리율이 처리수를 순환하는 경우 0.7~3.6%이었는데, 처리수를 배출하는 경우 3.2-5.7%로 증가하였다. 처리 수를 순환하는 경우 GAC의 충진량이 증가함에 따라, 가역적 여과저항(Rr)과 비가역적 여과저항(Rir)은 감소하는 경향을 보였 다. 그러나 총여과저항(Rt)은 거의 일정하였고, 물 역세 회복률(Rb)은 다소 증가하는 경향을 보였다.

Recently, amorphous granular starch (AGS) or non-crystalline granular starch (NGS) is of great interest because it has specific physicochemical properties compared to native starches. Various approaches have been taken to prepare gelatinized starch while still maintaining its granular shape. The granular cold-water soluble starch (GCWS) can be prepared by alcoholic-alkaline treatment or by using liquid ammonia and ethanol. However, these starches exhibit significant deformation and shrinking, and chemical treatments may raise safety issues for their potential food applications. Therefore, in this study, the optimization of preparation method for amorphous granular potato starch (AGPS) was investigated using ethanol and heat treatments. Response surface methodology (RSM) and central composite design (CCD) were used to find the optimum conditions for AGPS preparation based on granule integrity and birefringence. Optimum conditions were 53.3% ethanol and 93.87oC heat treatment for 15 min. Prepared AGPS maintained its granular structure and lost birefringence, crystallinity, and DSC amylopectin melting peak, suggesting that proper AGPS could be made using optimized conditions.

Western flower thrips, (Pergande) (Thysanoptera: Thripidae) have been recognized as serious pests worldwide. Commercially available chemical pesticides challenges against the resistance of the pest and safety to consumers. Herein we investigated the usability of soil-treatment of entomopathogenic Beauveria bassiana (Bb) ERL isolates in tomatoes. Bb-egfp was highly virulent to western flower thrips in laboratory conditions and colonized in soil, which provided a chance for western flower thrips larvae to contact the colonized fungal mass. In a glasshouse trial, Bb ERL836 and Bb ERL1578 granule (GR) were applied to soil surface and mixed well, and five females were infested to each pot of tomato 3 days after the application. The two treatments significantly reduced thrips population in tomatoes 20 and 40 days post applications, comparable to the control efficacy of clothianidin granule (GR) formulation. In the following field trial, the two ERL fungal treatments showed 69.2% and 61.5% of control efficacy, which were similar to that of clothianidin GR (76.9%). This work suggests that applied B. bassiana colonized in soil well and thrips larvae easily contacted the fungal mass, which possibly enabled the control strategy to be alternative way to the chemical control.

The characteristics of filter/adsorber granular activated carbon (F/A GAC) were investigated by measuring various parameters, which include surface area, pore volume, abrasion number, floater, and water-soluble ash. The correlation between parameters was also evaluated. Moreover, rapid small-scale column test (RSSCT) was conducted for adsorption characteristics. Thirteen F/A GAC were tested, and the average values of abrasion number and water-soluble ash were 88.9 and 0.15%, respectively. F/A GAC with the larger external surface area and greater mesopore volume had the lower abrasion number, which indicated that it was worn out relatively easily. Water-soluble ash of coconut-based GAC (about 2.6%) was greater than that of coal-based GAC (less than 1%), and the pH of solution was increased with GAC, which had the higher water-soluble ash. On the other hand, floater of thirteen F/A GAC was divided as two groups, which one group had relatively higher floater (2.7~3.5%) and the other group had lower floater (approximately 0.5%). The results of RSSCT indicated that coconut-based GAC (i.e. relatively higher water-soluble ash) had less adsorption capacity. Moreover, adsorption capacity of coal-based GAC with larger surface area and greater mesopore volume was superior to others.