Adsorption of methylene blue from aqueous solutions by pyrolusite ore

In this study, the adsorption of methylene blue dye was examined by using pyrolusite ore as a low-cost alternative adsorbent source. Pyrolusite, which contains mainly MnO2, is a manganese ore. The effects of the initial concentration of dye, contact time, initial pH of solution, adsorbent dosage, stirring speed of solution, and average particle size of adsorbent on the adsorption of methylene blue were studied. It was found that the percentage of the adsorbed dye increased with increasing the amount of pyrolusite. While the initial dye concentration, initial pH, contact time, stirring speed, particle size, and adsorbent dosage were 25 ppm, 6, 90 min, 250 rpm, 63 µm, and 12 g/l, respectively, the efficiency of dye adsorption on pyrolusite ore was 99%. The isotherm and kinetic studies relating to this adsorption process were also made. It was found that the equilibrium data followed the Langmuir isotherm model while the kinetic of process could be described by the pseudo-second order kinetic model

Investigation of Dissolution of Zinc Powder Obtained Waste Alkaline Battery in Sodium Hydroxide Solutions

Atık pillerin metal içerikleri metalürjik yöntemler yardımıyla geri kazanılabilir. Bu yöntemlerden birisi hidrometalurjik metottur ve sulu çözeltilerde kimyasal reaksiyonlar yardımıyla metal, metal tuzları ve bileşiklerinin üretimini kapsar. Metodun ilk aşaması katı sıvı kütle transferini içeren liç prosesidir. Liç işleminde katı madde bir çözücü ile çözündürülür ve metal değerler çözelti ortamına transfer edilir. Bu çalışmada, atık alkali pillerdeki çinko pil tozunun sodyum hidroksit çözeltilerindeki çözünürlüğü incelenmiştir. Deneylerde pil tozunun çözünürlüğü üzerine çözelti derişimi, reaksiyon sıcaklığı, katı tanecik boyutu, katı/sıvı oranı ve karıştırma hızının etkileri araştırılmıştır. Derişim, sıcaklık ve karıştırma hızının artmasıyla,  katı/sıvı oranı ve katı tanecik boyutunun ise azalmasıyla çözünürlüğün arttığı tespit edilmiştir. Elde edilen deneysel bulgulara göre, diğer parametrelere nazaran reaksiyon sıcaklığı ve çözelti derişiminin çinko tozun çözünürlüğü üzerinde önemli bir etkiye sahip olduğu söylenebilir. Çözelti derişimi 0,5 mol/L iken 120 dakikalık liç süresinden sonra pil tozundaki çinkonun  %19’unun çözündüğü, derişim 2,5 mol/L değerine arttırıldığında ise sadece 20 dakikalık liç süresinde çinkonun %99’unun çözündüğü belirlenmiştir. Sıcaklık 20 °C den 60 °C’ye yükseldiğinde sırasıyla 120 dakika ve 30 dakika liç süresinden sonra pil tozundaki çinkonun çözünürlüğünün %96,7 ve %98,3 olduğu tespit edilmiştir.Metal contents of waste batteries can be recovered by metallurgical methods. One of these methods is hydrometallurgical route, and it involves the production of metal, metalsalts and compounds by means of chemical reactions in aqueous solutions. First step of hydrometallurgy is leaching process containing a solid to liquid mass transfer. In the leaching process,solid material is dissolved by a solvent, and metal values are transferred into solution medium. In thisstudy, it wasinvestigated dissolution ofzinc powder in waste alkaline batteries in sodium hydroxide solutions. In the experiments, the effects of solution concentration, reaction temperature, particle size of solid, solid to liquid ratio, and stirring speed on dissolution of battery powder were studied. It wasfound that the dissolution increased with an increase in concentration, reaction temperature and stirring speed, and with a decrease solid‐to‐liquid ratio and in particle size. According to the experimental results obtained, it can be said that the reaction rate and solution concentration compared to other parameters have an important effect on dissolution of zinc powder. At a solution concentration of 0,5 mol/L, it was determined that 19% of zinc in battery powder dissolved after 120 min of leaching time, while at a concentration of 2,5 mol/L, 99% of zinc dissolved only after 20 min of leaching time. It was found that the extent of leaching of zinc in battery powder was 96,7% to 98,3% when the temperature rose from 20 °C to 60 °C after 120 min and 30 min of leaching time, respectively

Adsorption of Ni (II) Ions from aqueous solutions by kaolinite

Heavy metal ions have very serious harmful effects on human health, living creatures and ecological system. Heavy metal ions from water sources and waste water should be removed and reduced to allowable levels. Several methods are used to remove heavy metal ions from aqueous solutions. Among these methods, adsorption is one of the most common and widely used methods. In this study, the adsorption of Ni (II) heavy metal ion from aqueous solutions was aimed by using kaolin as a low-cost alternative adsorbent source. The effects of parameters such as the amount of adsorbent, the concentration of initial Ni(II) ions, temperature, the initial pH of the solutions and contact time the effect of on adsorption were investigated. It has been determined that the adsorption efficiency decreases with increasing initial Ni (II) ion depending on the duration of the contact, the adsorption efficiency increases with increasing pH value and the adsorption capacity of kaolin decreases with increasing temperature. The efficiency of adsorption increased with increasing the adsorbent dosage. The isotherm and kinetic studies relating to this adsorption process show that the equilibrium data follow the Langmuir isotherm while the process kinetic obeys by the pseudo-second order kinetic model

Kaolin adsorption performance for cadmium (II) from aqueous solution

In this study, the adsorption of cadmium ions from aqueous solutions by natural kaolin were studied in a batch adsorption system. The effect of parameters such as initial pH, initial concentration of cadmium ions, temperature, and adsorbent dosage on adsorption process was examined. It was observed that the adsorption extent of cadmium ion increased with increasing initial pH of solution, amount of adsorbent, and contact time, but with decreasing the initial concentration of cadmium ion and temperature

Adsorption of Cu(II) Ions with pumice

Clay minerals are frequently used natural adsorbents in removing heavy metal ions from the waste solid by the adsorption process. In this study, removal of Cu (II) metal ions from aqueous solutions was investigated using natural pumice as an adsorbent source. The copper solutions were prepared by dissolving CuSO4.5H2O in distilled water. All adsorption experiments were carried out at the laboratory temperature. All experiments were carried out in 150 mL sealed flasks. In each experiment, a certain amount of pumice (0.1-0.5 g/L) solution was added after a 50 mL solution of Cu (II) was placed in a given initial concentration (0.00005-0.0005 mol/L). The stirring speed was set at 200 rpm. The processes were performed for various contact times (5-180 min). The initial pH’s of the sample solutions were adjusted with diluted H2SO4. At the end of each contact time, the amount of Cu (II) ion in solution was determined by AAS (Perkin Elmer AAnalyst 800) and the amount of Cu(II) ion adsorbed by the pumice was calculated from the difference between the amount of copper determined before and after the treatment. In order to demonstrate the adsorption removal efficiency of some heavy metal ions, different studies have been carried out with low cost killer with metal binding capacity. In this context, different clay minerals such as activated carbon which is an expensive adsorbent, activated carbon, bentonite, sepiolite, kaolin, geotite and pumice which are obtained from more economical biomass are used in adsorbtion studies. The adsorption capacity was found to be lower when pumice was compared with other killers. Cu (II) ions were removed with 91 % yield

Adsorption study of Lead Ions from Aaueous solutions on pumice

Abstract— Heavy metals in water and wastewaters are one of the most important problems for the environment and human health. Lead is one of the most toxic heavy metals. It is widely used in many applications such as, production of lead acid batteries, solder, alloys, ammunition, pigments, glazes and plastic stabilizers. According to WHO permitted limitation of lead in drinking water is 10 µg/L. Therefore, lead in water resources should be removed to decrease amount of it. In this study, the removal of lead ion from aqueous solution by pumice was investigated in a batch adsorption system. Adsorption dosage, initial metal ion concentration, and pH on metal ion removal has been studied. Batch adsorption experiments were carried out at 20 oC, in 150 mL conical flasks. The solutions containing Pb+2 ions were prepared by dissolving weighed quantities of Pb(NO3)2.4H2O in distilled water. In each adsorption test, after the volume of 50 mL lead solution at a definite initial concentration (0.005-0.05 mmol/L was placed into the glass flask, a given amount of adsorbent (0.2-0.5 g) was added to solution. The average particle size of pumice sample used in the study was -200 mesh. Flask content was shaken at 200 rpm for various contact time. At the end of the experiment time, lead ions remaining in solution was determined by flame AAS (Perkin Elmer AAnalyst 800). The amount of lead adsorbed by pumice was calculated from difference between the ion concentration before and after process. While the initial concentration, initial pH of solution, contact time, stirring speed and adsorbent dosage were 0.01 mmol/L, 5.25, 180 min, 200 rpm, and 0.4 g, respectively, the efficiency of lead adsorption on pumice was 98 %

Adsorption of methylene blue from aqueous solutions by pyrolusite ore

In this study, the adsorption of methylene blue dye was examined by using pyrolusite ore as a low-cost alternative adsorbent source. Pyrolusite, which contains mainly MnO₂, is a manganese ore. The effects of the initial concentration of dye, contact time, initial pH of solution, adsorbent dosage, stirring speed of solution, and average particle size of adsorbent on the adsorption of methylene blue were studied. It was found that the percentage of the adsorbed dye increased with increasing the amount of pyrolusite. While the initial dye concentration, initial pH, contact time, stirring speed, particle size, and adsorbent dosage were 25 ppm, 6, 90 min, 250 rpm, 63 µm, and 12 g/l, respectively, the efficiency of dye adsorption on pyrolusite ore was 99%. The isotherm and kinetic studies relating to this adsorption process were also made. It was found that the equilibrium data followed the Langmuir isotherm model while the kinetic of process could be described by the pseudo-second order kinetic model