Adsorption kinetics and isotherm of methylene blue and its removal from aqueous solution using bone charcoal

Abstract

This study aims at describing the removal of methylene blue (MB) from aqueous solution using bone charcoal (BC) as an adsorbent material. The effects of dye concentration, pH, contact time and the adsorbent dose were investigated. The chemical composition and solid structure of BC were analyzed using X-ray diffraction (XRD) and scanning electronic microscopy (SEM). The surface area was measured via the Brunauer-Emmett-Teller (BET) isotherm. The experimental data were analyzed with Langmuir, Freundlich and Temkin isotherm models. The results show that the main component of BC is calcium hydroxylapatite (Ca 5 (PO 4 ) 3 OH). The BET Suface area of BC is approximately 100 m 2 /g. The experimental adsorption isotherm complies with Langmuir equation model (R 2 = 0.99) and the maximum amount of adsorption (q max ) was 5 mg/g. The elevation of BC dose led to a decrease in q max , however, increasing the pH led to the elevation of dye adsorption. The kinetic studies revealed that the adsorption of MB is rapid and complies with the pseudo second-order kinetic (R 2 [ 0.99). Apart from R 2 , four error functions have been used for the validation of data. Analysis of data with Dubinin-Radushkevich isotherm showed that the energy of MB adsorption process onto BC was 2.65 kJ/mol, which implies that the adsorption of MB with BC is a physical adsorption.

Sorption of 17β-estradiol from aqueous solutions on to bone char derived from waste cattle bones: Kinetics and isotherms

“…322 This suggests that the rate limiting step could be chemical sorption 323 or ion exchange [29]. Such behaviour of bone char has been 324 reported by various researchers [19,30,31]. 325 Intraparticle diffusion model 326 The kinetic data of E2 adsorption was also analyzed using 327 Weber-Morris intraparticle diffusion model.…”

“…Q2 17 Micropollutants in water are a rapidly emerging global problem 18 that seriously threatens environmental and human health. There 19 are several natural and synthetic chemicals that interfere with the 20 endocrine system of humans and animals commonly known as the 21 endocrine disruptive chemicals (EDCs). These chemicals have an 22 antagonistic effect on the aquatic species and human beings.…”

“…[7]. It has already proved its efficiency in removing 73 pyrogen such as endotoxin [13], air pollutant [14], bacterial spores 74 [15], heavy metals [16][17][18], dyes [19,20] and organic compounds 75 [21,22] was varied between 0.5 and 50 g L À1 . These affecting parameters 149 have been discussed in detail in the Results and discussion section.…”

“…The R L value 182 indicates the adsorption situation to be irreversible: R L = 0, 183 favourable: 0 < R L < 1, linear: R L = 1 and unfavourable: R L > 1 184 [19,24]. 185 The Freundlich isotherm model is an empirical equation, which 186 in its linear form is expressed as:…”

Kinetic and Thermodynamic Study of Phenol Removal from Water Using Activated Carbon Synthesizes from Avocado Kernel Seed

“…The validity and applicability of the isotherm models were confirmed by calculating the standard normal deviation (SND) and average relative error factor between the experimental data and the model estimates. The mathematical equation of SND and ARE is given below in equation 4 and 5 [31,32]. …”