코팅 고형물질의 물리, 화학성과 코팅배율이 당근코팅 종자의 발아력에 미치는 영향

강점순,최영환,손병구 密陽産業大學校 農業技術開發硏究所 1999 農業技術開發硏究所報 Vol.3 No.3

코팅의 목적은 기계화 정밀파종하여 파종과 솎음 노력을 절감하는데 있다. 코팅 고형물질의 용적밀도는 dialite, kaolin, talc 및 diatomaceous earth등이 낮았고 기공성도 많았다. 수분보유력이 우수한 고형물질은 bentonite와 dialite였으며, 각각 184% 및 173%의 수분을 보유할 수 있었다. 반면 calcium carbonate, calcium oxide, fly ash등은 수분보유력이 낮은 코팅 고형물질이였다. 코팅 고형물질의 pH는 kaolin, diatomaceous earth, dialite등은 pH가 각각 6.8, 7.6 및 7.4로 중성이었으나, limestone, calcium oxide, bentonite 등은 pH가 12.8, 13 및 10으로 강알카리였다. 전기전도도는 강알카리인 limestone, calcium oxide에서 높았다. 코팅 고형물질을 EDS로 분석한 결과 Talc는 주성분이 Si(71%)였고 Mg도 29% 함유하였다. 반면 calcium carbonate는 주성분이 Ca(66.6%)였으며, 그외에 Si(22.9%)와 Mg(10.5)를 함유하였다. 종자의 입단형성은 talc, talc + calcium carbonate 혼합물질, diatomaceous earth 등에서 우수하였다. 코팅종자의 경도는 bentonite 코팅은 경도가 가장 높았다. 코팅층의 붕괴 형태는 diatomaceous earth, talc, limestone, zeolite, 및 fly ash는 파열형이었고, 용해형은 calcium carbonate와 calcium oxide등이였다. 반면 bentonite와 vermiculite는 팽창형이었다. 코팅층의 분해는 diatomaeous earth가 가장 빨랐고 calcium carbonate, kaolin등도 비교적 빠른 고형물질이였다. 코팅배율이 높아지면 발아속도(T50)은 지연되었다. 당근종자에서 적정 코팅배율은 19.0배가 좋았다. The purpose of seed coating is to enlarge the seed size, to enable the mechanical planting, and to save the labor for thinning. Bulk density of coating particulate matters in dialite, kaolin, talc and diatiomaceous earth was low and the porosity was high. The particulate matters with high water holding capacity were bentonite and dialite, and they were 184% and 173%, respectively. On the meanwhile, those with low water holding capacity were calcium carbonate, calcium oxide, and fly ash. The pH of kaolin, diatomaceous earth, and dialite were 6.8, 7.6, and 7.4, and that of limestone, calcium oxide, and bentonite were 12.8, 13.0, and 10.0, respectively. High electro-conductivity was shown in limestone and calcium oxide. When we analyzed with EDS, the main component of talc was Si(71.0%) and Mg(29.0%), and that of calcium carbonate was Ca(66.6%), Si(22.9%), and Mg(10.5%). High granulation capacity was observed from talc, talc + calcium carbonate mixture, and diatomaceous earth, Seeds coated with bentonite showed the highest hardness. The dissolving type of seeds coated with diatomaceous earth, talc, limestone, zeolite, and fly ash showed split type, and those with calcium carbonate and calcium oxide showed melt type. However, those with bentonite and vermiculite showed swell type. Diatomaceous earth took the shortest dissolving time of coating, followed by calcium carbonate and kaolin. The germination speed (T50 ) was delayed as the size of coated seeds was bigger. The optimum size of coating was 19.0 ratio in carrot.

Ca($OH_2$)-$H_2 O$-$CO_2$계의 기액반응으로부터 비정질 탄산칼슘의 합성 및 결정화

임재석,김가연,임굉,Im, Jae-Seok,Kim, Ga-Yeon,Im, Goeng 배재대학교 공학연구소 2004 공학논문집 Vol.5 No.1

수산화칼슘현탁액과 탄산가스를 출발물질로 15~$50^{\circ}C$의 온도에서 기액반응으로 비정질 탄산칼슘($CaCO_3$.$nH_2 O$)의 생성과정을 전기저도도의 연속측정법, X-선회절법 및 투과전자현미경법을 이용하여 조사한 결과, 반응초기생성물은 비정질 탄산칼슘으로 반응현탁액의 전기전도도는 비정질 탄산칼슘의 생성 중 크게 강하하고 있으며, 이것은 수산화칼슘의 입자표면이 비정질 탄산칼슘미립자로 뒤덮여 용해를 방해받는 것과 비정질 탄산칼슘이 용액 속에서 불안정하여 즉시 용해한 다음 석출하여 칼사이트로 전이되어 미세한 침강성 탄산칼슘이 나란히 결합한 연쇄형 칼사이트가 생성된다. 비정질 탄산칼슘이 연쇄형 칼사이트로 변화하는 동안 현탁액의 전기전도도는 급격히 회복되고 이 과정에서 고농도 수산화칼슘현탁액의 외관점도가 상승한다. 이것은 연쇄형 칼사이트의 뒤얽힘에 의한 것이며, 다시 전기전도도의 1회 회복단계 이후에는 미반응 수산화칼슘에 의하여 비정질 탄산칼슘이 생성이 소멸되어 칼사이트의 성장반응이 이루어지고 pH가 9.5이하에서 연쇄형 칼사이트는 결합부분이 먼저 용해하여 결정질 탄산칼슘으로 분리생성된다. 비정질 탄산칼슘의 생성 및 합성온도의 영역은 전기전도도법에서 $15^{\circ}C$일 때 1차 강하단계(a-단계)에서 가장 적합하다. The synthesis and crystallization of amorphous calcium carbonate($CaCO_3$.$nH_2 O$) obtained from gas-liquid reaction between aqueous solution of calcium hydroxide and carbon dioxide at 15~$50^{\circ}C$ are investigated by electrical conductometry, XRD and TEM. The results are as follows: The initial reaction products prior to the formation of precipitated calcium carbonate is amorphous calcium carbonate. The electrical conductivity values in the slurry are decreased during the formation of amorphous calcium carbonate which covers particle surface of calcium hydroxide and retard the dissolution of calcium hydroxide into the solution. that amorphous calcium carbonate is unstable in the aqueous solution and crystallizes finally to calcite by the through-solution reaction. While amorphous calcium carbonate crystallizes into chain-like calcite, the conductivity values are recovered rapidly and the apparent viscosity of slurry containing higher concentration of calcium hydroxide increase. At below pH 9.5, chain-like calcite separates into individual particles to form precipitated calcium carbonate. The formation and synthetic temperature range of amorphous calcium carbonate is most suitable a primary decreasing step(a-step) at $15^{\circ}C$ in the electrical conductometry.

펠렛 피복물질의 물리, 화학적 특성이 당근 펠렛종자의 발아력에 미치는 영향

강점순(Jum Soon Kang),손병구(Beung Gu Son),최영환(Young Whan Choi),이용재(Yong Jae Lee),박영훈(Young Hoon Park),최인수(In Soo Choi) 한국생명과학회 2007 생명과학회지 Vol.17 No.12

펠렛의 목적은 기계화 정밀파종하여 파종과 솎음노력을 절감하는데 있다. 펠렛 피복물질의 용적밀도는 dialite, kaolin 및 talc 등이 낮았고 기공성은 높았다. 보수력이 우수한 피복물질은 bentonite와 dialite 이었으며, 184% 및 173%의 수분을 보유할 수 있었다. 반면 calcium carbonate, calcium oxide, fly ash등은 보수력이 낮은 펠렛 피복물질이었다. 펠렛 피복물질의 pH는 kaolin과 dialite에서 각각 6.8 및 7.4로 중성이었으나, limestone, calcium oxide, bentonite 등은 pH가 12.8, 13 및 10으로 강알카리였다. 전기전도도는 강알카리인 limestone, calcium oxide에서 높았다. 이와 같이 높은 pH와 전기전도도를 보인 피복물질들은 당근종자의 펠렛에 적합하지 않았다. 펠렛 피복물질를 EDS로 분석한 결과, Talc는 주성분이 Si (71%)이었고, Mg도 29% 함유하였다. 반면 calcium carbonate의 주요성분은 Ca (66.6%)이었으며, 이외에 Si (22.9%)와 Mg (10.5%)를 함유하였다. 펠렛 형성정도는 kaoline, talc 및 talc + calcium carbonate 혼합재료에서 우수하였다. 펠렛종자의 경도는 bentonite로 펠렛된 종자에서 가장 높았다. 수분흡수 후 펠렛층의 분해형태는 talc, limestone, zeolite, 및 fly ash는 열개형이었고, 용해형은 calcium carbonate와 calcium oxide등 이었다. 반면 bentonite와 vermiculite는 팽창형이었다. 수분흡수 후 펠렛층의 분해는 calcium carbonate 및 kaolin으로 펠렛된 종자에서 분해가 가장 빨랐다. 펠렛배율이 높아지면 발아속도(T50)는 지연되었다. 당근종자에서 적정 펠렛배율은 19배가 좋았다. Seed pelleting is generally conducted in order to save the labor for sowing and thinning by enabling the precision mechanical planting. In the present study, the influence of physical and chemical properties of pelleting solid materials was investigated on carrot seed germination. Among the pelleting solid materials evaluated, dialite, kaolin, and talc showed low bulk density and high porosity. Bentonite and dialite carried high water holding capacities of 184% and 173%, respectively, while calcium carbonate, calcium oxide, and fly ash showed relatively low water holding capacity. The pH of kaolin (6.8) and dialite (7.4) were close to neutral, while limestone (12.8), calcium oxide (13.0), and bentonite (10.0) were highly basic. High electro-conductivity was shown in limestone and calcium oxide. EDS analysis revealed that the main elemental compositions of talc were Si (71.0%) and Mg (29.0%), and those of calcium carbonate were Ca (66.6%), Si (22.9%), and Mg (10.5%). High granulation capacity was observed from talc and the mixture of talc and calcium carbonate. Seeds pelleted with bentonite showed the highest hardness. The dissolving type of the pellet layer after imbibition was split type in talc, limestone, zeolite, and fly ash, melt type in calcium carbonate and calcium oxide, and swell type in bentonite and vermiculite. The shortest dissolving time of pellet layer was observed from calcium carbonate and kaolin. The germination speed (T50) was delayed as the size of pelleted seeds increased. The optimum size of pelleting was 19 ratio in carrot.

성견 3면 골내낭에서 calcium sulfate를 calcium carbonate와 혼합이식 및 차단막으로 사용시 치주조직의 치유효과

정유선,김종관,Jeong, Yu-Seon,Kim, Chong-Kwan 대한치주과학회 1996 Journal of Periodontal & Implant Science Vol.26 No.3

Various bonegraft materials and the technique of guided tissue regeneration have been used to regenerate lost periodontal tissue. Calcium sulfate has been known as a bone graft material because of good biocompatibility, rapid resorption and effective osteoinduction. It has been known that calcium sulfate works as a binder to stabilize the defect when it is used with synthetic graft materials. The effects on the regeneration of pericxiontal tissue were studied in dogs after grafting 3-wall intrabony defects with calcium carbonate and calcium sulfate and covering with calcium sulfate barrier. The 3-wall intrabony defectstdmm width, 4mm depth, 4mm length) were created in anterior area and treated with flap operation alone(contol group), with porous resorbable calcium carbonate graft alonetexperirnental group 1), with calcium sulfate graft alonetexperimental group 2) and with composite graft of 80% calcium carbonate and 20% calcium sulfate with calcium sulfate barriertexperimental group 3). Healing responses were histologically observed after 8 weeks and the results were as follows: 1. The alveolar bone formation was $0.59{\pm}0.19mm$ in the control group, $1.80{\pm}0.25mm$ in experimental group 1, $1.61{\pm}0.21mm$ in experimental group 2 and $1.94{\pm}0.11mm$ in experimental group 3 with statistically significant differences between control group and all experimental groups(P<0.05). There were statistically significant differences between experimental group 1 and group 2 (P<0.05). 2. The new cementum formation was $0.48{\pm}0.19mm$ in the control group. $1.72{\pm}0.26mm$ in experimental group 1, $1.43{\pm}0.17mm$ in experimental group 2, $1.89{\pm}0.15mm$ in experimental group 3 with statiscally significant differences between control group and all experimental groups (p<0.05). There were statistically significant differences between experimental group 1 and group 2, and between experimental group 2 and group 3(P<0.05). 3. The length of junctional epithelium was $1.61{\pm}0.20mm$ in the contol group, $0.95{\pm}0.06mm$ in experimental group 1, $1.34{\pm}0.16mm$ in experimental group 2, $1.08{\pm}0.11mm$ in experimental group 3 with statiscally significant differences between control group and experimental group 1. and btween control group and experimental group 3(p<0.05). There were statistically significant differences between experimental group 1 ,and group 2, and between experimental group 2 and group 3(P<0.05). 4. The connective tissue adhesion was $1.67{\pm}O.20mm$ in the control group, $1.33{\pm}0.24mm$ in experimental group 1. $1.23{\pm}0.16mm$ in experimental group 2, $1.08{\pm}0.14mm$ in experimental group 3 with statistically significant differences between control group and all experimental groups(p<0.05). There were nostatistically significant differences between all experimental groups. As a result, epithelial migration was not prevented when calcium sulfate was used alone, but new bone and cementum formation were enhanced. Epithelial migration was prevented and new bone and cementum formation were also enhanced when calcium carbonate was used alone and when both calcium carbonate and calcium sulfate were used.

식물추출액을 이용한 지반 고결제 개발

박성식,최선규,남인현 한국지반공학회 2012 한국지반공학회논문집 Vol.28 No.3

This paper presents an environment-friendly sand cementation method by precipitating calcium carbonate using plant extracts. The plant extracts contain urease like Sporosarcina pasteurii, which can decompose urea into carbonate ion and ammonium ion. It can cause cementation within sand particles where carbonate ions decomposed from urea combine with calcium ions dissolved from calcium chloride or calcium hydroxide to form calcium carbonate. Plant extracts, urea and calcium chloride or calcium hydroxide were blended and then mixed with Nakdong River sand. The mixed sand was compacted into a cylindrical specimen and cured for 3 days at room temperature (18℃). Unconfined compression test, SEM and XRD analyses were carried out to evaluate three levels of urea concentration and two different calcium sources. As urea concentration increased, the unconfined compressive strength increased up to 10 times those without plant extracts because calcium carbonate precipitated more, regardless of calcium source. It was also found that the strength of specimen using calcium chloride was higher than that of specimen using calcium hydroxide.

괴재 및 전로슬래그를 이용한 CO₂ 저감 및 칼슘 추출 후 슬래그 활용

유영석 ( Yeongsuk Yoo ),최홍범 ( Hongbeom Choi ),방준환 ( Jun-hwan Bang ),채수천 ( Soochun Chae ),김지환 ( Ji-whan Kim ),김진만 ( Jin-man Kim ),이승우 ( Seung-woo Lee ) 한국공업화학회 2017 공업화학 Vol.28 No.1

광물탄산화 기술은 천연광물 및 산업부산물에 포함된 칼슘이나 마그네슘을 이산화탄소와 반응시켜 탄산염을 생성하는 기술로 이산화탄소를 열역학적으로 안정한 형태로 저장할 수 있는 기술이다. 본 연구는 철강슬래그를 이용한 이산화탄소 저감 및 추출 후 슬래그 재활용을 통해 환경적 부담 및 공정 비용 절감을 절감할 수 있는 광물탄산화 상용화 기술 개발을 목표로 설정하였다. 추출 용매(염화암모늄)를 사용하여 괴재 및 전로슬래그로부터 칼슘을 추출하고 추출된 칼슘을 이산화탄소와 반응시켜 순도 98% 이상의 탄산칼슘을 합성하였다. 또한 칼슘 추출 후 슬래그를 건축자재(패널)로 활용하는 기술을 개발하였다. 슬래그의 칼슘 추출효율에 따라 상이한 결과를 보였지만 광물탄산화 전체 공정에 있어 중량 비(약 80-90%)를 차지하는 칼슘 추출 후 슬래그(잔여슬래그)의 활용을 통해 광물탄산화 공정으로부터 배출되는 산업부산물의 양을 최소화하고자 하였다. 잔여슬래그는 시멘트 패널 제작에 활용되는 규사미분 대체 물질로서 이용하였고 기존 시멘트 패널과 물성평가(압축강도 및 휨강도)를 상호 비교하였다. 용액 내 칼슘 농도는 유도결합 플라즈마 분광분석기(Inductively coupled plasma optical emission spectrometer, ICP-OES)를 사용하여 분석하였다. 합성한 탄산칼슘은 X선 회절 분석법(X-ray diffraction, XRD)을 이용하여 결정학적 특성 및 정량 분석하였고 주사 전자 현미경(Field emission scanning electron microscope, FE-SEM)을 사용하여 표면 형상을 확인하였다. 시멘트 패널평가는 KS LISO 679에 준하여 패널 제작 및 패널의 압축강도와 휨강도를 측정하였다. Mineral carbonation is a technology in which carbonates are synthesized from minerals including serpentine and olivine, and industrial wastes such as slag and cement, of which all contain calcium or magnesium when reacted with carbon dioxide. This study aims to develop the mineral carbonation technology for commercialization, which can reduce environmental burden and process cost through the reduction of carbon dioxide using steel slag and the slag reuse after calcium extraction. Calcium extraction was conducted using NH₄Cl solution for air-cooled slag and convert slag, and ≥ 98% purity calcium carbonate was synthesized by reaction with calcium-extracted solution and carbon dioxide. And we conducted experimentally to minimize the quantity of by-product, the slag residue after calcium extraction, which has occupied large amount of weight ratio (about 80-90%) at the point of mineral carbonation process using slag. The slag residue was used to replace silica sand in the manufacture of cement panel, and physical properties including compressive strength and flexible strength of panel using the slag residue and normal cement panel, respectively, were analyzed. The calcium concentration in extraction solution was analyzed by inductively coupled plasma optical emission spectrometer (ICP-OES). Field-emission scanning electron microscope (FE-SEM) was also used to identify the surface morphology of calcium carbonate, and XRD was used to analyze the crystallinity and the quantitative analysis of calcium carbonate. In addition, the cement panel evaluation was carried out according to KS L ISO 679, and the compressive strength and flexural strength of the panels were measured.

자건대멸, 칼슘강화소재를 첨가한 우유 및 칼슘강화우유가 흰쥐의 칼슘흡수율과 골대사에 미치는 영향

조진호(Jin-Ho Jo),김병기(Byung-Gi Kim),한찬규(Chan-Kyu Han),정은봉(Eun-Bong Jung),조승목(Seung-Mock Cho) 한국식품영양과학회 2008 한국식품영양과학회지 Vol.37 No.4

본 연구는 고칼슘멸치가 흰쥐의 칼슘대사에 미치는 영향을 조사하기 위해 수행되었다. 실험처리는 시유와 칼슘강화우유, 칼슘강화소재(탄산칼슘, 젖산칼슘) 및 고칼슘대멸 등 5처리군으로 하였고, 대멸분말의 칼슘함량을 고려하여 최종식이의 칼슘함량은 1%가 되도록 semi-purified diet(AINdiet)에 혼합한 식이를 5주 동안 급여하였다. 대퇴골의 길이는 대조군인 우유군(M)와 칼슘강화우유군(M2)이 실험군중 통계적으로 유의하게 길었고(p<0.05), BMD, BMC 및 칼슘함량은 고칼슘멸치군(MA)이 실험군 중 가장 높았다. 체외(in vitro) 칼슘흡수율은 고칼슘대멸군이 7.30%로 가장 높았고, 생체내(in vivo) 칼슘흡수율은 실험군간 차이는 없었지만 고칼슘대멸군이 27.50%로 가장 높았다. 혈청 중 총콜레스테롤과 HDL-콜레스테롤 농도는 대조군과 고칼슘대멸군간에 통계적인 차이가 있었다(p<0.05). Creatinine 농도는 대조군, 고칼슘대멸군 및 탄산칼슘군이 칼슘강화우유군에 비해 통계적으로 높았다(p<0.05). 칼슘과 osteocalcin 농도 및 ALP활성은 실험군간에 차이가 없었지만 고칼슘대멸군이 높았다. SGOT활성은 칼슘강화우유군에 비해 대조군, 고칼슘대멸군 및 탄산칼슘군이 유의하게 높았다(p<0.05). 이상의 결과에서 고칼슘대멸군은 칼슘강화소재와 칼슘강화우유에 비해 대퇴골의 BMD, BMC 및 칼슘함량을 증가시켰으며, 생체내외(in vivo, in vitro) 칼슘흡수율에서도 다른 처리군보다 높았다. 본 결과는 대멸을 활용한 고칼슘식품 개발에 유용한 평가 자료로 활용될 것으로 사료된다. This study was performed to investigate the effect of calcium-rich large anchovy on calcium metabolism in rats for 5 weeks. Experimental animals were randomly assigned to 5 treatments with 14 heads of Spraque Dawley male rats in each group. The experimental diets were as follows; market milk group (M) as control, market milk+calcium-rich large anchovy group (MA), market milk+calcium carbonate group (MC), market milk+calcium lactate group (ML), and enriched-calcium market milk group (M2), which were formulated with commercially semi-purified rat chow (AIN-diet) to maintain the same level of calcium (1%) in all groups. Femur lengths of M and M2 groups were significantly higher than other groups. Bone mineral density (BMD) and bone mineral content (BMC) and calcium content of femur were the highest in MA group than other groups. In vitro and in vivo calcium absorption rates were high in MA group (7.30% vs 27.50%) compared with those of the other groups. Serum total-cholesterol and HDL-cholesterol levels were significantly different between M group and MA group (p<0.05). Creatinine levels were significantly higher in M, MA and MC groups than in M2 group (p<0.05). Serum calcium, osteocalcin and ALPase activities were higher in calcium-rich large anchovy (MA) group among the treatments, but there was no significant difference. SGOT activity was significantly lower in M2 group than those of M, MA and MC groups (p<0.05). These results may indicate that the calcium-rich large anchovy has enforced the BMD, BMC and calcium absorption rates of in vitro and in vivo compared with the other groups and might be a calcium-enriched food with large anchovy.

수삼의 탄산칼슘용액 침지에 따른 물성 변화

최인학 ( In Hag Choi ),김학윤 ( Hak Yoon Kim ),이기동 ( Gee Dong Lee ) 한국식품저장유통학회(구 한국농산물저장유통학회) 2013 한국식품저장유통학회지 Vol.20 No.1

This study investigated the textural changes after the calcium-pectin bonding of ginseng roots and their vinegar and calcium solution immersion. The strength and breakdown of the ginseng roots increased according to the increase in the calcium carbonate concentration, with the highest in the 0.7~1.0% calcium carbonate. The hardest and softest ginseng roots were obtained in the 1.0% calcium carbonate concentration. The strength, brittleness and hardness of the ginseng roots that were soaked in 1% calcium carbonate and 5~6% acidity vinegar continued to increase with the long-term storage of the ginseng root drink. The softness of the ginseng root that was dipped in 5% acidity vinegar with 1.0% calcium carbonate decreased with the long-tern storage of the ginseng root drink. Thus, calcium and vinegar immersion of ginseng roots could prevent softening and clouding during the long-term storage of the ginseng root drink.

Chemical Conversion of Carbon Dioxide via Aqueous Fixation using Divalent and Monovalent Metal Cations in Reject Brine Solutions

( Dongwoo Kang ),( Jinwon Park ) 한국폐기물자원순환학회(구 한국폐기물학회) 2019 ISSE 초록집 Vol.2019 No.-

In order to minimize the impact caused by global warming, the efforts to reduce the amount of carbon dioxide emission have been made for decades. There are various technologies in carbon reduction fields and usually they are called CCUS (Carbon Capture Utilization and Storage). In the CCUS technologies, carbon dioxide produced from various sources including power plants, industrial process are separated and processed. In CCS method, carbon dioxide is separated followed by compression and storage in the deep ocean or underground. However, to regenerate the absorbents, especially in wet absorption method, heat is essentially required to heat up the absorbents. To reduce this energy requirement problems and to enhance the economic feasibility of the whole process, the concept to make carbon dioxide into the reusable one has come arise. One of the most studied one is to make carbon dioxide into the metal carbonates by combining them with metal ions. However, securing metal cations are one of the problems. Some obtained its sources from natural minerals such as limestone. However, it seems not adequate to use resources to treat carbon dioxide, hence, we tried to use reject brine which have been produced from refined salt production facilities. In this process, natural seawater is drawn and sodium chloride is separated to make commercial salt product. And remaining solution is heated up to separate remaining salts. As a result, final solution becomes super-concentrated due to the evaporation of the solvent. When this reject brine is directly released to the near shore, it can trigger partial changes in concentration of near-ocean resulting in the negative impact in ecosystem. If divalent metal cations such as calcium or magnesium ions can be obtained in this reject brine solution, both securing sources and preventing environmental impact can be achieved at the same time. Herein, we developed a new carbon utilization method using calcium and magnesium cations dissolved in seawater-based industrial wastewater. Calcium and magnesium were separated in the form of hydroxide precipitate. Using 30 wt% aqueous monoethanolamine (MEA) solution, carbon dioxide was captured and reacted with the hydroxides to produce calcium carbonate and magnesium carbonate. After Ca²⁺ and Mg²⁺ separation, sodium chloride was used to produce sodium bicarbonate. The entire process produced 0.3819, 0.2549 and 0.4579 mol of calcium carbonate, magnesium carbonate and sodium bicarbonate, respectively. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were conducted to investigate their crystal structure. Moreover, FT-IR spectroscopy was utilized to investigate the ionic species under Na⁺-rich conditions.

The formation of web-like connection among electrospun chitosan/PVA fiber network by the reinforcement of ellipsoidal calcium carbonate

Sambudi, N.S.,Kim, M.G.,Park, S.B. Elsevier 2016 Materials Science and Engineering C Vol. No.

<P>The electrospun fibers consist of backbone fibers and nano-branch network are synthesized by loading of ellipsoidal calcium carbonate in the mixture of chitosan/poly(vinyl alcohol) (PVA) followed by electrospinning. The synthesized ellipsoidal calcium carbonate is in submicron size (730.7 +/- 152.4 nm for long axis and 212.6 +/- 51.3 nm for short axis). The electrospun backbone fibers experience an increasing in diameter by loading of calcium carbonate from 71.5 +/- 23.4 nm to 281.9 +/- 51.2 nm. The diameters of branch fibers in the web-network range from 15 nm to 65 nm with most distributions of fibers are in 30-35 nm. Calcium carbonate acts as reinforcing agent to improve the mechanical properties of fibers. The optimum value of Young's modulus is found at the incorporation of 3 wt.% of calcium carbonate in chitosan/PVA fibers, which is enhanced from 15.7 +/- 3 MPa to 432.4 +/- 943 MPa. On the other hand, the ultimate stress of fibers experiences a decrease. This result shows that the fiber network undergoes changes from flexible to more stiff by the inclusion of calcium carbonate. The thermal analysis results show that the crystallinity of polymer is changed by the existence of calcium carbonate in the fiber network. The immersion of fibers in simulated body fluid (SBF) results in the formation of apatite on the surface of fibers. (C) 2015 Elsevier B.V. All rights reserved.</P>