천연 및 전처리 제올라이트에 의한 2 가 중금속 이온 제거능의 비교 검토

감상규,김덕수,이민규 한국환경과학회 1999 한국환경과학회지 Vol.8 No.3

The three domestic natural zeolites(Yong dong-ri (Y), Daesin-ri (D), Seogdong-ri (S)) harvested in Kyeongju-shi and Pohang-shi, Kyungsangbug-Do, were pretreated with each of the NaOH, Ca(OH)_2, and NaOH following HCl solutions, and the removal performances of divalent heavy metals(Cu, Mn, Pb, and Sr) for natural and pretreated zeolites were investigated and compared in the single and mixed solutions. The natural zeolite-heavy metal system attained the final equilibrium plateau within 20 min, irrespective of initial heavy metal concentration. The heavy metal uptakes increased with increasing initial heavy metal concentration and pH. The heavy metal uptakes for natural zeolites decreased in the following sequences : D>Y>S among the natural zeolites; Pb>Cu>Sr>Mn among the heavy metals. The pretreated zeolites showed higher heavy metal removal performances than natural zeolites and decreased in the order of NaOH, NaOH following HCl, Ca(OH)_2 treatment among the pretreatment methods. The heavy metal ion exchange capacity by natural and pretreated zeolites was described either by Freundlich equation or Langmuir equation, but it followed the former better than the latter. The heavy metal uptakes for natural zeolites decreased in the mixed solution, in comparing with those in the single solution and especially, the manganese uptake decreased greatly in the mixed solution. The pretreated zeolites showed the improved removal performances of heavy metals in the mixed solution than in the single solution and the heavy metal uptakes by those in the mixed solution showed the same trends in the single solution among the chemical treatment methods and heavy metals.

사용 후 유리세라믹(Lithium-Aluminum-Silicate)을 활용한 중금속 제거 기초 연구

고민석,왕제필 한국자원리싸이클링학회 2022 資源 리싸이클링 Vol.31 No.4

In this study, the heavy metal ions (of Pb, Cd, Cr, and Hg) in wastewater were removed using a spent Li2O-Al2O3-SiO2-based crystallized glass previously used as an induction top plate material. Changes in the removal efficiency of heavy metals according to different reaction parameters, such as the amount of zeolite used as a heavy-metal adsorbent, adsorption time, initial concentration of the heavy metals, and pH of the initial solution, were investigated. As the amount of zeolite added increased, the heavy-metal removal efficiency also increased. Adsorption time had a considerable influence on adsorption characteristics, and the removal efficiency of all heavy metals increased with increasing adsorption time. In the case of Cd, the removal efficiency was greatly improved depending on the adsorption time. The initial concentration of the heavy-metal solution did not affect the removal efficiency; however, the initial pH of the heavy-metal solution affected the removal efficiency. More specifically, the removal efficiency of Cd increased while that of Pb and Cr decreased with increasing pH. The adsorption characteristics of Hg were not significantly affected by pH. 본 연구에서는 인덕션 탑플레이트(induction top plate) 소재로 사용된 후 폐기되는 사용 후 Li2O-Al2O3-SiO2계 결정화 유리를 활용하여 중금속 용액 내 존재하는 중금속(Pb, Cd, Cr6+, Hg) 이온들의 제거 실험을 진행하였다. 중금속 흡착제로 사용된 흡착제의 양, 흡착 반응시간, 초기 중금속 원소의 농도, 초기 용액의 pH 등의 반응 조건에 따른 중금속 제거 효율의 변화를 조사하였다. 사용 후 LAS 첨가량이 증가할수록 중금속 제거 효율이 상승하였다. 흡착 반응 시간은 흡착 특성에 큰 영향을 미치는 것으로 확인되었으며, 모든 중금속 원소들의제거 효율이 상승하였다. 특히 반응 시간에 따라서 Cd의 경우 흡착제거 효율이 크게 개선되었다. 초기 중금속 용액 농도는 중금속 제거 효율에 영향을 미치지 않았다. 중금속 용액의 pH는 중금속 제거 효율에 영향을 미쳤는데, Cd의 경우 pH증가에 따라 중금속 제거 효율이 증가하였으며, Pb, Cr6+는 감소하였다. Hg는 pH가 흡착 특성에 큰 영향을 미치지 않았다.

Removal of Heavy Metals by an Enriched Consortium

이은영,Joung Soo Lim,Kyung Hwan Oh,Jae Yeon Lee,Seog Ku Kim,Yoo Kyung Lee,김근 한국미생물학회 2008 The journal of microbiology Vol.46 No.1

An enriched consortium obtained from lake-sediment was developed for the removal of heavy metals such as Cu, Pb, Cr, Ni, and Zn from heavy metal-contaminated water. The removal efficiency of heavy metals in a shaking condition was generally higher than that in the static state. After the fifteenth enrichment with assorted heavy metals, the removal efficiencies in the shaking and static condition at an average concentration of 100 mg/L of each heavy metal were approximately 99~100% and 95~100%, respectively, depending on the type of heavy metal. An aerobically grown, pure culture isolated from an enriched culture was analyzed by 16S rRNA sequencing and identified as Ralstonia sp. HM-1. This strain was found to remove various heavy metals with an efficiency of approximately 97~100% at an average concentration of 200 mg/L of each heavy metal.

Heavy metal removal from aqueous solution by granular hydrated Portland cement

Peng Cheng,Yongxiang Ren,Lei Yang,Rituan Li,Xue Wang,Bin Li,Honglin Yuan 한국화학공학회 2022 Korean Journal of Chemical Engineering Vol.39 No.12

Granular hydrated Portland cement (HPC) was prepared as adsorbent to remove heavy metals in aqueoussolution. Batch experiment results confirmed that heavy metals were removed through a combination of adsorptionand precipitation. Adsorption played a more important role in the initial stage of the removal process or at lower concentrationsof the heavy metals. After adsorption equilibrium was obtained in two days, the removal process continuedfor about three days due to the precipitation. Besides precipitation, the maximum Langmuir adsorption capacity reached132.27, 87.14, 123.43 and 112.05mg/g for Pb, Cu, Zn, and Cd, respectively. When various heavy metals coexisted, theremoval capacity followed the order of Cu>Pb>Cd>Zn. The adsorption on the surfaces of HPC was mainly governedby surface precipitation and Ca2+ exchange, as suggested by XRD, SEM-EDS and released Ca2+ results. Most of theadsorbed heavy metals on the HPC and the precipitation formed in the liquid phase were stable under neutral andalkaline conditions. Overall, HPC particles exhibited a large potential for heavy metal removal. When cement-relatedmaterials containing HPC are employed for heavy metal removal, the dissolution of the precipitate at low pH mightfacilitate the migration of the heavy metals.

pH 변화에 따른 중금속 수용액의 반응 메커니즘

송수욱 ( Song Su Ug ),정호진 ( Jeong Ho Jin ) 한국수처리학회 2004 한국수처리학회지 Vol.12 No.1

This study was designed to set up a theoretical mechanism for removal and separation of heavy metal ions from aqueous solutions by analysing reaction between pH and heavy metal ions, and to offer useful data for treatment applications of wastewater containing heavy metals in the future. The obtained results are as follows: Each heavy metal ion has a unique curve between pH and residual heavy metal concentration. When two types of heavy metals are complexed, the reaction rate between OH- and heavy metal ion is more affected by ionization strength rather than competitive reaction. When three types of heavy metals are combined, the ultra-fine particle is formed at about 1-2 lower PH than in the case that independently existed. This is because chemical reaction was caused by complicated reactions of pH of the minimum soluble product, ionization strength, and competitive reaction. The electric field makes ultra-fine particles having a very small amount of charge move more easily than large colloidal particles. Therefore, this study shows that it is possible to improve the efficiency of selective flocculation by electrolysis at PH which forms ultra-fine particles of metal-hydroxides by the application of the results.

Self-assembled flower-like TiO₂ on exfoliated graphite oxide for heavy metal removal

Lee, Y.C.,Yang, J.W. Korean Society of Industrial and Engineering Chemi 2012 Journal of industrial and engineering chemistry Vol.18 No.3

We describe that a hydrothermal preparation of flower-like TiO<SUB>2</SUB>-graphene oxide (GO-TiO<SUB>2</SUB>) hybrid by stirring a titanium oxide precursor in isopropyl alcohol with GO colloidal solution. The GO-TiO<SUB>2</SUB> hybrid was applied for the removal of heavy metal ions from water. The oxygenated functional groups of exfoliated graphite oxide showed a high removal capacity of heavy metals. The flower-like TiO<SUB>2</SUB> on GO structure significantly improved the removal efficiency of heavy metals. For example, the GO-TiO<SUB>2</SUB> hybrid adsorption capacities of heavy metal ions, after 6h and 12h of hydrothermal treatment at 100<SUP>o</SUP>C, were respectively 44.8+/-3.4 and 88.9+/-3.3mg/g for removing Zn<SUP>2+</SUP>, 65.1+/-4.4 and 72.8+/-1.6mg/g for removing Cd<SUP>2+</SUP>, and 45.0+/-3.8 and 65.6+/-2.7mg/g for removing Pb<SUP>2+</SUP> at pH 5.6. In contrast, colloidal GO under identical condition showed removal capacities of 30.1+/-2.5 (Zn<SUP>2+</SUP>), 14.9+/-1.5 (Cd<SUP>2+</SUP>), and 35.6+/-1.3mg/g (Pb<SUP>2+</SUP>). TiO<SUB>2</SUB> blossoms markedly formed upon GO as the hydrothermal treatment time at 100<SUP>o</SUP>C increased from 6h to 12h. Longer treatment times resulted in an increase in the surface area of GO-TiO<SUB>2</SUB> hybrid and thus its removal capacity of heavy metal increased.

Trends in Bioremediation of Heavy Metal Contaminations

Parasakthi JEYAKUMAR,Chandrani DEBNATH,R Vijayaraghavan,Muthusivaramapandian MUTHURAJ 대한환경공학회 2023 Environmental Engineering Research Vol.28 No.4

Heavy metal contamination of the ecosystem remains one of the severe global threats. Even in trace quantities, heavy metals and metalloids such as chromium, lead, mercury, cadmium, nickel, and cobalt are toxic and carcinogenic, posing a serious threat to human life. Certain microbes and plants have evolved detoxifying pathways to fight the harmful effects of these inorganic metals, paving the door for bioremediation. Because of its environmentally benign nature, economic viability, and low labor and effort requirements, bioremediation outperforms other approaches in eliminating heavy metals. This review highlights the potential of microbes on remediation of heavy metals in the context of environmental protection and also focuses on the critical tolerance mechanisms used by these microbes in combating heavy metal contaminations. Furthermore, the bioremediation potential of bacteria, fungus, algae, plants, biosurfactants, biofilms and genetically altered microorganisms for the removal of these heavy metals was reviewed in this study. Applying these techniques as a sustainable environmental technology in the near future has shown synergistic benefits with a many-fold increase in the removal of heavy metals.

천연광물의 양극성 표면개질을 이용한 상수원수 중 중금속제거 특성

김남열,김영희 한국환경보건학회 2019 한국환경보건학회지 Vol.45 No.6

Objectives: The most commonly detected heavy metals in rocks and soils, including Pb, Cd, Cu, Fe, Mn and As, are representative pollutants discharged from abandoned mines and have been listed as potential sources of contamination in drinking water. This study focused on increasing the removal efficiency of heavy metals from drinking water resources by surface modification of natural adsorbents to reduce potential health risks. Methods: Iron oxide coating and graft polymerization with zeolites and talc was conducted for bipolar surface modification to increase the combining capacity of heavy metals for their removal from water. The removal efficiency of heavy metals was measured before and after the surface modification. Results: The removal efficiency of Pb, Cu, and Cd by surface modified zeolite showed 100, 92, and 61.5%, respectively, increases compared to 64, 64, and 38% for non-modified zeolite. This implies that bipolar surface modified natural adsorbents have a good potential use in heavy metal removal. The more interesting finding is the removal increase for As, which has both cation and anion characteristics showing 27% removal efficiency where as non-modified zeolite showed only 2% removal. Conclusions: Zeolite is one of the most widely used adsorptive materials in water treatment processes and bipolar surface modification of zeolite increases its applicability in the removal of heavy metals, especially As.

Eggshell and coral wastes as low cost sorbents for the removal of Pb2+, Cd2+ and Cu2+ from aqueous solutions

Mahtab Ahmad,Adel R.A. Usman,이상수,Sung-Chul Kim,Jin-Ho Joo,양재의,옥용식 한국공업화학회 2012 Journal of Industrial and Engineering Chemistry Vol.18 No.1

Rapid industrialization in Korea has led to the discharge of heavy metals to water, posing a threat to the environment. The use of natural materials as low cost sorbents for the removal of heavy metals from aqueous solutions has recently received increasing attention. The present study was conducted to evaluate the effectiveness of eggshell and coral wastes for the removal of Pb2+, Cd2+ and Cu2+ from aqueous solutions. Batch equilibrium experiments were conducted using heavy metal solutions with waste eggshell and coral powders. Langmuir and Freundlich adsorption models were used for the mathematical description of sorption equilibrium. The maximum amounts of metals (Cu2+, Pb2+ and Cd2+) adsorbed were found to be 32.3, 22.9 and 4.47 mmol kg1 for eggshell and 6.77, 5.52 and 1.03 mmol kg1 for coral wastes,respectively. At low initial concentrations the adsorption of heavy metals onto both sorbents can be described as H-type (except for the Cd adsorption onto coral), indicating high-affinity isotherms and strong adsorbate–adsorptive interactions such as inner sphere complexes. However, the metal adsorption was described by L-type isotherm at high initial concentrations. Based on the distribution coefficient (Kd) values and the percentage of metal removed, the selectivity sequence in eggshells and coral wastes was found to be Pb2+ > Cu2+ > Cd2+. The Kd values and the percentage of metals removed were higher in eggshells than coral with its higher capacity to adsorb heavy metals. Based on the results of the present study, eggshell and coral wastes can be used for the removal of heavy metals from aqueous solutions.

Bacillus sp.의 생장과 인 제거능에 대한 단일 및 2종 혼합 중금속의 독성 평가

김덕원,박지수,오은지,유진,김덕현,정근욱 한국환경과학회 2021 한국환경과학회지 Vol.30 No.11

In this study, the effects of single and binary heavy metals toxicity on the growth and phosphorus removal ability of Bacillus sp.. known as be a phosphorus-removing microorganism, were quantitatively evaluated. Cd, Cu, Zn, Pb, Ni were used as heavy metals. As a result of analysis of variance of the half of inhibition concentration and half of effective concentration for each single heavy metal treatment group, the inhibitory effect on the growth of Bacillus sp. was Ni < Pb < Zn < Cu < Cd. And the inhibitory effect on phosphorus removal by Bacillus sp. was Ni < Pb < Zn < Cu < Cd. When analyzing the correlation between growth inhibition and phosphorus removal efficiency of a single heavy metal treatment group, a negative correlation was found (R2 = 0.815), and a positive correlation was found when the correlation between IC50 and EC50 was analyzed (R2 = 0.959). In all binary heavy metal treatment groups, the interaction was an antagonistic effect when evaluated using the additive toxicity index method. This paper is considered to be basic data on the toxic effects of heavy metals when phosphorus is removed using phosphorus removal microorganisms in wastewater.