본 연구는 해조류인 괭생이 모자반을 탄화하여 만든 바이오차의 중금속 흡착 및 제거 효과를 확인하고 중금속 흡착제로 이용 가능성을 확인하고자 연구가 수행되었다. 모자반 바이오차(SBC)는 500℃조건에서 2시간 열분해를 통해 생산하였다. 중금속 흡착실험은 Pb, Cd, Cu 및 Zn의 각 농도별 흡착량을 확인하였으며, Freundlich 및 Langmuir 등온흡착모델을 통해 중금속 흡착 효율성을 확인하였다. 모자반 바이오차의 중금속 제거효율은 Pb, Cd, Cu 및 Zn에서 각각 97.3, 85.2, 76.4 및 42.0%로 Pb＞Cd＞Cu＞Zn 순의 제거효율을 보였다. 등온흡착결과로 Freundlich 등온흡착패턴은 L형이었으며, 흡착강도(1/n)는 0.49 ~ 0.80 범위로 조사되었다. Langmuir 등온흡착식에서 최대흡착량은 Pb, Cd, Cu 및 Zn에서 각각 200, 92.6, 47.8 및 70.4 mg g-1이었으며, 흡착강도는 각각 0.4950, 0.1004, 0.0245 및 0.0188로 조사되었다. 본 실험 결과로 볼 때 모자반 바이오차는 중금속 흡착제로써 활용이 가능할 것으로 보여지며, 이를 활용하기 위한 추가 연구가 필요하다고 보여진다.

이 연구는 장석 반암에 대한 자연수내 중금속 흡착제로서의 활용 가능성을 검토하기 위해 수행되었다. '맥반석'으로 불리는 연구대상 암석은 프로필리틱 변질작용으로 생성된 녹니석, 녹염석, 방해석을 포함하는 변질 장석반암이다. 용출 실험결과, 용출원소의 대부분은 Ca와 Na이며, 이들은 장석 반정보다는 석기에서 그 용출량이 많다. 흡착 실험결과, Pb, Cu, Fe는 반응 1시간 이내에 각각 99, 98, 97%가 흡착되었으나 As는 24시간 동안 25%가 흡착되었다. 변질 장석 반암의 Pb, Cu, Fe에 대한 높은 흡착능력은 수질정화용 중금속 흡착제로서의 활용 가능성이 있음을 시사한다.

The adsorption of heavy metals in the waste water carried out on the various domestic clays and waste pottery. The effect of parameters such as pH, temperature, adsorption time and coexisting cations on the adsorption ability and characteristics were investigated to find out whether the clays could be used as adsorbents. Adsorption equilibrium was reached within 20 minutes on all the clays. The optimum pH was found to be above 5. When other cations such as Cu(II) or Zn(II) coexisted with Pb(II), the adsorption amount of Pb(II) decreased because of competing adsorption.

Acid mine drainage (AMD) has emerged as one of the greatest environmental threats facing mining industry owing to its characteristic low pH, high acidity and elevated concentrations of metals and sulphate content. This study evaluates the efficiency of fly ash as a low cost material to remove heavy metals (Cu, Fe, Mn and Pb) from AMD. The effects of varying contact time, dosage and pH on adsorption were investigated using synthetically prepared AMD. The experiments was conducted in series of batches for adsorption using a mechanical shaker with 50mL AMD at various dosages of fly ash (0.1 - 0.8g/L) and coagulation using a standard jar tester of 1000mL AMD with chemical coagulant dosages (0.5 - 10g/L). Tests were also conducted with 50mL AMD without fly to evaluate the treatment efficiency of fly ash to chemicals. All tests were performed in duplicate for consistency and accuracy. The chemical composition of fly ash was characterized by X-ray fluorescence (XRF) and the result shows the fly ash is rich in calcium (CaO 54.9%). Leaching test of the fly ash was conducted using KLST and TCLP method to compare the results and evaluate the behavior of leaching ash in replenishing acidic media at low pH such as acid mine drainage. pH plays a significant role in heavy metal uptake in this study with increased in pH value the removal rate increased. The optimum dosage for Adsorption was found to be 0.4g/L with 60 min optimum contact time and coagulation 6mg/L with reduced metal concentrations much less than regulation standards for Cu, Fe, Mn and Pb. From all tests conducted fly ash proves more efficient with over 96% removal even at low dosages. The effectiveness of the treatment process will depend on the quality of the fly ash and the AMD. Therefore the use of fly ash for treatment of mine wastewater would represent a new market opportunity for this waste product. Recycling of fly ash will conserve the natural raw materials and abridge the disposal cost. It will also create new revenues and business opportunities while protecting the environment. Most significantly, the two waste products acid mine drainage and fly Ash could be neutralized and when reacted together to produce much cleaner water broadly compared to post process water derived from Lime treated AMD and sulfates removal rates were in the range of 90% in both experiments. Fly ash is more economical, sustainable.

본 연구는 포항과 경주 일대에서 채취한 제올라이트와 벤토나이트의 광물조성과 입자 크기에 따른 중금속 흡착정도를 파악하는 것이다. 제올라이트 시료의 주 구성광물은 모데나이트, 크라이놉틸로라이트, 휼란다이트 등이며, 벤토나이트 시료는 주로 몬모릴로나이트로 구성되어 있다. 흡착 실험에 사용한 중금속은 Cd, Cr, Cu, Mn, Pb로 10 ppm과 20 ppm의 두 가지 농도를 이용하여 실험을 실시하였다. 대부분의 시료는 Cr을 제외한 다른 중금속에서 평균 80% 이상의 흡착율을 나타내며, Pb는 95% 이상의 흡착율 보였다. 제올라이트가 벤토나이트 시료보다 중금속 이온의 흡착에 더 효과적이며, 중금속의 농도가 높은 경우 흡착율이 감소하는 경향을 나타낸다.

This study was performed to investigate the possible uses of waste sludge for the removal of heavy metal ions. The adsorption experiments were conducted with wastes such as sewage treatment sludge, water treatment sludge and oyster shell to evaluate their sorption characteristics. Heavy metals selected were cadmium, copper and lead. In the sorption experiments on the sewage treatment sludge, water treatment sludge, oyster shell and soil, sorption occurred in the beginning and it reached equilibrium after 40 minutes on the oyster shell and 4 hour on the sewage treatment sludge and water treatment sludge. Results of Freundlich isotherms indicated that sewage treatment sludge could be properly used as an adsorbent for heavy metals and sorption strength of heavy metals was in the order of Pb > Cu > Cd. In the influence of pH on the adsorbents, sorption rate was more than 80% in pH 4 and most of heavy metals were adsorbed in pH 9. Adsorption rate of Cd decreased with decreasing pH and then adsorption rate of Cu was lower in soil.

Surface complexation models(SCMs) have been performed to predict metal ion adsorption behavior onto the mineral surface. Application of SCMs, however, requires a self-consistent approach to determine model parameter values. In this paper, in order to determine the metal ion adsorption parameters for the triple layer model(TLM) version of the SCM, we used the zeta potential data for Zeolite and Kaolinite, and the metal ion adsorption data for Pb(Ⅱ) and Cd(Ⅱ). Fitting parameters determined for the modeling were as follows ; total site concentration, site density, specific surface area, surface acidity constants, etc. Zeta potential as a new approach other than the acidic-alkalimetric titration method was adopted for simulation of adsorption phenomena. Some fitting parameters were determined by the trial and error method. Modeling approach was successful in quantitatively simulating adsorption behavior under various geochemical conditions.