• 상하수도학회지
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• 제25권2호
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• pp.241-248
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• 2011

This research was performed to evaluate the efficacy of phosphate removal from wastewater by surface-modified wood powder and to clarify the removal mechanisms. In this work, Pinus rigida which is abundant in Korea and has little economic value was used in preparation of the wood powder as a sorbent material. The experiments were carried out in 2 phases, isothermal adsorption test and column test. The results of adsorption test fitted well both the Langmuir and Freundlich isothermal equations. Adsorption capacity was highest with the bark powder followed by the mixed powder(50% bark powder and 50% woody powder) and woody powder. Phosphate removal efficiency was as high as 98% at initial phosphate concentration of 50mg/L. Specific surface area of the powder increased following the experiment and phosphate removal was speculated to occur through adsorption mechanism. Energy dispersive X-ray analysis(EDXA) revealed that the phosphate adsorbed onto the surface of the powder was in the form of strengite($FePO_{4}$).

• Nuclear Engineering and Technology
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• 제8권2호
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• pp.69-76
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• 1976

핵연료 재처리 과정이나 원자력발전소에서 대량으로 발생되는 비교적 반감기가 긴 핵종들(Sr-90, Ru-106, Cb-137, Ce-144)의 화학응집제와 국산점토 광물(montmorillonite)에 의한 제거 효율을 결정하기 위해 본 실험이 수행되었다. Phosphate process는 Ce-144의 제거에 있어서 99.5% 이상의 극히 좋은 효율을 나타냈고, lime-soda process는 Sr-90에 대하여 93%의 높은 제거율을 보였으며, Cs-187에 대해서는 copper-ferrocyanide가 제거율 99%의 매우 적절한 화학 응집제임을 나타냈다. Phosphate나 lime-soda process에서 가장 좋은 제거효율은 PH 11 이상에서 얻어졌다. 그리고 NaCl로 처리된 montmorillonite가 방사성 핵종들은 제거하는데 있어서 natural montmorillonite 보다 향상된 제거 효율을 보여주었다.

• 상하수도학회지
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• 제25권5호
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• pp.725-730
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• 2011

In this study, it was investigated that the feasibility of utilizing inorganic mesostructures for removal of phosphate in water. The comparison of the efficiency for phosphate adsorption between inorganic mesostructures was conducted. X-ray diffraction(XRD) and Brunauer-Emmett-Teller(BET) methods were used to characterize these mesostructures. The efficiencies of silica and titanium mesostructures for the removal of phosphate from aqueous solution were investigated. Equilibrium data were analyzed using the Langmuir isotherm. The maximum adsorption capacities of mesostructure adsorbents were found to be 49.3 and 19.5 mg $g^{-1}$ for the titanium and silica mesostructures, respectively. The adsorption kinetics was described by a pseudo third-order kinetic model. The results from this study indicated that the titanium mesostructure has the potential to be utilized for the cost-effective removal of phosphate from wastewater.

• 공업화학
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• 제24권5호
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• pp.558-561
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• 2013

본 연구에서는 인 결합 단백질(phosphate-binding protein)이 세포질(cytoplasm)에서 발현되는 재조합 대장균(Escherichia coli)을 제조하였으며, 이를 이용하여 수중에 함유된 인의 제거에 대하여 고찰하였다. 이 균주를 6 h 동안 배양하여 1.0, 1.5, 2.0 mg/L의 인을 처리하였을 때, 각각 90, 49, 41%의 제거효율을 도출하였으며, 우수한 인 제거 능력(specific phosphate removal)을 나타내었다. 또한, 세포의 Optical density를 2.5, 5.0으로 조절하여 운전하였을 때, 인의 제거효율이 향상됨을 알 수 있었으며, 2.0 mg/L 인을 80%까지 제거시킬 수 있었다. 이 연구를 통하여 얻어진 새로운 생물기술은 수계의 부영양화 문제를 해결하는데 효과적으로 사용될 수 있을 것이다.

• 미생물학회지
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• 제29권2호
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• pp.117-122
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• 1991

In order to improve the removal ability of phosphate, Spheroplast fusions were performed among auxotrophic mutants of Aeromonas hydrophila isolated from waste water, named A13 and A14, Aci37 auxotrophic mutant of Acinetobactercalcoaceticus, and auxotrophic E. coli HR262/pCE27 carring pit gene. Eight fusants obtained from this experiment showed different biochemical characteristics. When the rate of phosphate uptake among fusants (F1-F8) was investigated in Phosphate Uptake Medium (PUM), F8 strain showed the highest rate for phosphate removal, 7 times as much as control after two hours incubation. The role of cations ($Mg^{++}$ ,$Ca^{++}$ , $K^{+}$ in phosphate uptade by F8 was also investigated in PUM without each salt. $K^{+}$ seemed to be crucial. Being compared with phosphate untake rate in PUM, that in PUM without $K^{+}$ was reduced 1.5 times. Therefore, by applying F8 strain and $K^{+}$ in practical environmental system, the increased efficiency in phosphate removal can be derived.

• 한국산학기술학회논문지
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• 제13권10호
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• pp.4910-4916
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• 2012

세라믹담체에 적용한 4종의 해양박테리아 (Aeromonas hydrophila, Chryseomonas indologenes, Pseudomonas diminuta, Vibrio parahaemolyticus)의 저농도 질소 인 제거 효율의 변화를 분석하였다. 해양박테리아는 광양만에서 분리 동정하였다. 담체에 적용한 4종의 해양박테리아 모두 대조군에 보다 약 3배 정도의 성장률이 증가하였으며, 암모니아서 질소 제거효율도 30% 이상 증가하였다. 질산성 질소의 제거 효율은 A. hydrophila 균주가 가장 높았으며, 인의 제거는 P. diminuta 균주가 가장 높은 것으로 나타났다. 본 연구의 결과는 세라믹담체는 질소-인 제거 효율 증진에 좋은 재료이며, 분리된 해양박테리아는 현장의 저농도 질소-인 조절에 유용할 수 있음을 보여준다.

• 해양환경안전학회지
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• 제24권2호
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• pp.196-202
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• 2018

굴 패각과 같은 반응성 재료는 사용 목적에 적합한 전처리 조건을 선택할 필요가 있다. 본 연구에서는 인 농도 제어를 목적으로 효율적인 굴 패각 사용을 위한 전처리 조건을 제안하는데 목적을 둔다. 굴 패각의 전처리(소성 온도, 소성 시간, 입자 크기)에 따른 인산염 제거 효율을 조사하였다. 또한 XAFS 분석 및 등온 흡착 실험을 통해 굴 패각의 인산염 제거특성에 대해 조사하였다. 실험 결과 소성 온도는 $600^{\circ}C$, 소성 시간은 6 h, 입자 크기는 0.355~0.075 mm에서 우수한 제거 효율을 확인하였다. 등온 흡착 실험 결과 Langmuir 모델이 굴 패각의 흡착에 적합한 것으로 나타났다. XAFS 분석 결과 $600^{\circ}C$에서 소성시킨 굴 패각에는 인산칼슘이 생성된 것이 확인되었다. 즉 굴 패각의 칼슘 이온 용출에 의한 인산칼슘 형성이 인산염의 농도 감소에 기여하고 있음을 확인하였다.

• 상하수도학회지
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• 제30권6호
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• pp.663-671
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• 2016

Coagulation/precipitation process has been widely used for the removal of phosphate within domestic wastewater. Although Fe and Al are typical coagulants used for phosphate removal, these have some shortages such as color problem and low sedimentation velocity. In this study, both Fe and Al were used to overcome the shortages caused by using single one, and anionic polymer coagulant was additionally used to enhance sedimentation velocity of the precipitate formed. Batch experiments using a jar test were conducted with real wastewater, which was an effluent of the second sedimentation tank in domestic wastewater treatment plant. Response Surface Methodology was used to examine the responsibility of each parameter on phosphate removal as well as to optimize the dosage of the three coagulants. Economic analysis was also done on the basis of selling prices of the coagulants in the field. Phosphate removal efficiency of Fe(III) was 30% higher than those of Fe(II). Considering chemical price, optimum dosage for achieving residual phosphate concentration below 0.2 mg/L were determined to be 18.14 mg/L of Fe(III), 2.60 mg/L of Al, and 1.64 mg/L of polymer coagulant.

• 공업화학
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• 제31권5호
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• pp.495-501
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• 2020

In this study, zirconium fumarate of metal-organic framework (MOF-801) was solvothermally synthesized at 130 ℃ and characterized through powder X-ray diffraction (PXRD) analyses and porosity measurements from N₂ sorption isotherms at 77 K. The ability of MOF-801 to act as an adsorbent for the phosphate removal from aqueous solutions at 25 ℃ was investigated. The phosphate removal efficiency (PRE) obtained by 0.05 g/L adsorbent dose at an initial phosphate concentration of 60 ppm after 3 h was 72.47%, whereas at 5 and 20 ppm, the PRE was determined to be 100% and 89.88%, respectively, after 30 min for the same adsorbent dose. Brunauer-Emmett-Teller (BET) surface area and pore volume of the bare MOF-801 sample were 478.25 ㎡/g and 0.52 ㎤/g, respectively, whereas after phosphate adsorption (at an initial concentration of 60 ppm, 3 h), the BET surface area and pore volume were reduced to 331.66 ㎡/g and 0.39 ㎤/g, respectively. The experimental data of kinetic (measured at initial concentrations of 5, 20 and 60 ppm) and isotherm measurements followed the pseudo-second-order kinetic equation and the Freundlich isotherm model, respectively. This study demonstrates that MOF-801 is a promising material for the removal of phosphate from aqueous solutions.

• Membrane and Water Treatment
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• 제14권1호
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• pp.1-10
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• 2023

This study explored the feasibility of calcium-rich food waste, Mactra veneriformis shells (MVS), as an adsorbent for phosphate removal, and its removal efficiency was enhanced by the thermal activation process. The CaCO3 in MVS was converted to CaO by thermal activation (>800 ℃), which is more favorable for adsorbing phosphate. Thermal activation did not noticeably influence the specific surface area of MVS. The MVS thermally activated at 800 ℃ (MVS-800), showed the highest phosphate adsorption capacity, was used for further adsorption experiments, including kinetics, equilibrium isotherms, and thermodynamic adsorption. The effects of environmental factors, including pH, competing anions, and adsorbent dosage, were also studied. Phosphate adsorption by MVS-800 reached equilibrium within 48h, and the kinetic adsorption data were well explained by the pseudo-first-order model. The Langmuir model was a better fit for phosphate adsorption by MVS-800 than the Freundlich model, and the maximum adsorption capacity of MVS-800 obtained via the Langmuir model was 188.86 mg/g. Phosphate adsorption is an endothermic and involuntary process. As the pH increased, the phosphate adsorption decreased, and a sharp decrease was observed between pH 7 and 9. The presence of anions had a negative impact on phosphate removal, and their impact followed the decreasing order CO₃^2- > SO₄²- > NO₃^- > Cl^-. The increase in adsorbent dosage increased phosphate removal percentage, and 6.67 g/L of MVS-800 dose achieved 99.9% of phosphate removal. It can be concluded that the thermally treated MVS-800 can be used as an effective adsorbent for removing phosphate.