• 유기물자원화
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• 제30권1호
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• pp.33-39
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• 2022

혐기성 소화 슬러지 탈리여액을 대상으로 마그네슘 공급원이 인산암모늄마그네슘(MAP) 결정화에 의한 인산염 회수에 어떠한 영향을 미치는지 알아보기 위해 회분식 실험을 실시하였다. 마그네슘 공급원으로 염화마그네슘, 수산화마그네슘 그리고 산화마그네슘을 사용하여 다양한 pH (7.5, 8.0 및 8.5) 조건 및 Mg/P 몰 비율(1.0, 1.5, 2.0 및 2.5)에서 인산염 회수를 실시하였다. 그 결과, 마그네슘 공급원과 관계없이 pH 조건과 Mg/P 몰 비율이 높을수록 인산염 회수율이 증가하였다. pH가 가장 낮은 7.5의 조건에서는 Mg/P 몰 비율이 증가할수록 인산염 회수율이 증가하였는데 산화마그네슘, 수산화마그네슘, 염화마그네슘의 순으로 높았다. 그러나 pH가 가장 높은 8.5의 조건에서는 Mg/P 몰 비율과 관계없이 모든 마그네슘 공급원에서 90% 이상의 높은 인 회수율을 얻을 수 있었다. 따라서 낮은 pH 조건에서도 높은 인산염 회수율을 얻을 수 있었던 수산화마그네슘과 산화마그네슘이 경제적인 측면뿐만 아니라 효율적인 측면에서도 염화마그네슘을 대체할 수 있을 것으로 기대된다.

• 자원리싸이클링
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• 제33권2호
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• pp.16-23
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• 2024

해수나 염수에서 마그네슘을 추출하는 전해 반응은 마그네슘 이온을 주로 수산화마그네슘 형태로 마그네슘을 침전-회수하는 기술로, 양이온교환막, 음이온교환막, 전기투석, 비막 방식 등으로 분류된다. 최근 연구는 마그네슘 함유 해수나 염수를 사용하여 마그네슘의 회수 효율성 및 선택성 증진에 집중되며, 향후 일반 해수를 사용할 경우에도 효과적인 마그네슘 회수가 기대된다. 향후에는, 스케일업 시스템의 장기운전을 통해 마그네슘 및 다양한 유가물질에 대한 선택적 고효율 회수의 최적화와 더불어 경제성 및 환경성을 증진하는 것이 중요하다. 함께 막의 수명 및 교체주기를 고려하여 운전비용을 현실적으로 산정해야 하며, 다양한 인자에 대한 모니터링 데이터를 기반으로 상세하고 실용적인 공정 모델이 필요하다.

• 한국물환경학회지
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• 제31권4호
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• pp.387-391
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• 2015

This study was performed to evaluate the effect of pH (8-12) and molar ratio of magnesium and phosphate ($[Mg^{2+}]/[PO_4{^{3-}}]$) (0.6-1.4) on struvite crystallization of anaerobic digester supernatant using seawater as magnesium source. pH range of 9-10 is favorable for ammonium and phosphate recoveries. The recovery efficiency of ammonium was highest at $[Mg^{2+}]/[PO_4{^{3-}}]$ of 1.0 and pH 10. On the other hand, high phosphate recovery efficiency (> 99%) was achieved at ($[Mg^{2+}]/[PO_4{^{3-}}]$) of 1.4 and pH 10. The results demonstrated that seawater can be considered as low-cost magnesium source to recover phosphorus from anaerobic digester supernatant.

• 한국미생물·생명공학회지
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• 제7권3호
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• pp.165-173
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• 1979

자연선조사한 대장균B주의 세포분열회복활성분을 구명코저 자외선내성균인 대장균 B/r 주의 초음파추출액으로부터 활성성분分을 분리한 결과 $\beta$-NAD가 관여함이 발표되었다. 본고에서는$\beta$-NAD 이외 Magnesium이 활성물질의 안정화가 중요한 역할을 나타냄을 구명하였으며 10~30%의 서당밀 도구배원심분리에 의해 2 개의 새로운 활성부분이 있음을 확인하였다. 2 개의 활성물질 가운데 하나는 원심관의 최하부에 위치하였으며 또 다른 하나는 상부의 분자량 45,000 부위에서 회수되었다. 하부에 위치한 활성획분은 Mg++이 그 활성에 무관하였으나 상부의 저분자 활성부분은 $Mg^{++}$을 첨가하지 않으면 회수가 불가능하였다. 저분자활성부분은 pronase에 대해 감수성이었으며 DNA-ligase 는 아님이 추정되었다. 초원심분리과정에 $N_2$ gas를 처리할 경우 aeration에 비해 약 2 배의 활성이 나타났다. $Mg^{++}$은 $\beta$-NAD에 또하나의 회복활성 및 필수적인자로 요구된다고 생각된다.

• 한국환경과학회지
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• 제10권5호
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• pp.381-386
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• 2001

The characteristics of precipitation separation and solvent extraction separation of magnesium from the waste bittern were studied experimentally In the result of precipitation separation, the size of magnesium hydroxide precipitated was not affected on pH, but decreased with increasing the precipitation temperature. The purity of magnesium oxide precipitated was increased with pH beyond pH 11. From the solvent extraction separation, the equilibrium extraction ratio of magnesium was increased with pH and temperature of extraction phase, the concentration of stripping phase, and with decreasing pH of stripping phase. The extractant of Aliquat 336 and Acid 810 mixture was more effective than that of DCH18C6 and $D_2EHPA$ mixture in the extraction separation of magnesium.

• The Korean Journal of Pain
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• 제13권1호
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• pp.31-37
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• 2000

Background: Recent studies suggested that a preoperative block of N-methyl-D-aspartate (NMDA) receptors with NMDA antagonists may reduce postoperative pain. In this double-blind study, magnesium sulfate, a natural NMDA receptor antagonist, was administered preoperatively to investigate the effects of magnesium sulfate on postoperative pain and pulmonary function. Methods: Seventy patients who were to undergo gastrectomy under general anesthesia were randomly assigned to one of three groups. Groups 2 and 3 received intravenous magnesium, preoperatively (Group 2: 50 mg/kg bolus, 7.5 mg/kg/hr for 20 hr, Group 3: 50 mg/kg bolus, 15 mg/kg/hr for 20 hr). Group 1 received normal saline as the control group. Visual analog scale (VAS) for postoperative pain and mood, cumulative analgesic consumption, recovery of pulmonary function and side effects were evaluated at 6, 24, 48 and 72 hours after the operation. Results: In Groups 2 and 3, plasma concentration of magnesium were significantly higher than in Group 1 at 6 and 20 hours after infusion (P<0.05). There were no significant differences in the analgesic consumption, and recovery of pulmonary function and the incidence of side effects at 6, 24, 48 and 72 hours after the operation among the three groups. In Group 3, pain scores at rest measured 24 and 48 hours after operation were lower than the control group, and pain scores when deep breathing were significantly lower than the control group at postoperative 6, 24, 48, and 72 hours. Conclusions: We conclude that intravenous infusion of greater amount of magnesium has little effectiveness in reducing postoperative pain. However, further studies are needed to characterize the clinical significance of these effects on postoperative pain.

• 자원리싸이클링
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• 제25권4호
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• pp.32-41
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• 2016

본 연구에서는 마그네슘 이온이 포함되어 있는 해수로부터 황산마그네슘 고체를 얻기 위한 실험을 진행하였다. 석출 실험은 마그네슘 회수의 3 단계(침전, 용출, 석출) 과정의 마지막 단계이다. 해수 대비 4배 농축된 마그네슘 용액에 아세톤을 주입하여 석출을 진행하였다. pH가 높을수록, 그리고 아세톤 주입 비율이 높을수록 생성효율이 높아졌다. 용액의 pH가 1.0 ~ 1.5이고, 용액 :아세톤 = 1 : 1.5 (v:v)일 때 99% 이상의 마그네슘이 황산마그네슘 수화물($MgSO_4{\cdot}6H_2O$)로 석출되었다. 석출공정에 사용된 아세톤은 분별증류에 의하여 회수하였다.

• 대한치과보철학회지
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• 제41권5호
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• pp.551-564
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• 2003

Statement of problem : Magnesium oxide may increase pH of alginate, and supply magnesium ions to the polymerization reaction of alginate. Purpose : This study was designed to evaluate the influence of incorporation of magnesium oxide to alginate composition. Material and Method : Seven kinds of experimental alginates were prepared and used for the experiments. Components with unchanging concentrations were sodium alginate 15%, calcium sulfate 14%, sodium phosphate 2%, and zinc fluoride 3%. Contents of magnesium oxide were varied as 0%, 1%, 2%, 3%, 4%, 5%, 6%. Diatomaceous earth were added to each experimental groups as balance to be 100%. Control group was a MgO 0% group. Working time, setting time, elastic recovery strain in compression, compressive strength and tear resistance were measured were measured. Sample size for each groups were 10. Arithmetic means were used as each groups representative values. Regression test between MgO contents and results, Duncan's multiple range test, and One-way ANOVA test were done between groups at level of 0.05. Results : 1 Magnesium oxide made the working time and setting time as longer(p<0.0001). 2 Magnesium oxide did not alter the elastic recovery(p>0.05). 3. Magnesium oxide contents between 2% and 4% exhibited the lowest strain in compression on alginates(p<0.0001). 4. Magnesium oxide made the compressive strength and the tear resistance stronger(p<0.0001). Conclusion : These results mean that setting time of alginate maybe controlled and that mechanical properties maybe improved by the incorporation of magnesium oxide into alginate, without any reduction of elasticity.

• 한국물환경학회지
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• 제32권4호
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• pp.343-348
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• 2016

A chemical sequencing batch reactor was operated to test the feasibility of nutrient recovery from a biological livestock wastewater treatment plant. Both phosphate and ammonia could be successfully recovered as magnesium ammonium phosphate (MAP) crystals. The contents of TP and TN in the recovered MAP crystals were 26.2% and 4.0%, respectively. Zn, Cr and Ti were identified in the crystals, but the contents remained below the Korean standard for an organic fertilizer. Chemical analyses confirmed that the MAP crystals could be useful phosphate fertilizers. On the other hand, the results of physical analyses using an X-ray diffractometer and an energy dispersive X-ray spectrometer strongly suggested that crystalline materials like magnesium potassium phosphate (KMP) and hydroxyapatite (HAP) were also formed during the MAP crystallization, depending on the availability of K⁺ and Ca²⁺.

• Animal cells and systems
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• 제7권2호
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• pp.169-171
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• 2003

Sodium, potassium, calcium, zinc and magnesium levels in the serum of 31 patients diagnosed as acute myocardial infarction were analyzed on admission (within 24 Hours) and after 48 hours. The results were compared with those of 26 age matched controls. No significant difference was observed in the mean sodium, potassium, calcium and zinc levels between the cases and controls. Compared to the controls, however, the variation in the level of magnesium is highly significant at the time of admission as well as after 48 hours. When the risk factors like diabetes mellitus, hypertension, smoking and alcohol were considered, it is found that there is no significant difference between the risk groups as well as between the patients. The alteration in magnesium level in acute myocardial infarction is independent of these risk factors. Within the first 24 hours, the significant decrease in serum magnesium (35-51％ fall when compared with the control group), correlates with its entry into the cell following ischemia. From this hypomagnesemic state, it rises to 9-22 times after 48 hours. This hyper-magnesemia after 45 hours is probably due to the shift of magnesuim from the intracellular fluid compartment to the extracellular fluid compartment that follows cellular recovery. Therefore, including magnesium in the immediate management of acute myocardial infarction will be beneficial in the early recovery.