This research tried to perform a comprehensive evaluation of dye (Reactive Red 120 (RR120)) removal by the surfactant-modified montmorillonite (Mt). For this purpose, the experiments were carried on at two levels. In the first level, the adsorption behavior of cetylpyridinium chloride monohydrate (CPCM) and alkyl dimethyl benzyl ammonium chloride (ADBAC) onto Mt was assessed by electrical conductivity technique. In this manner, the critical micelle concentration (CMC) point of ADBAC and CPCM were achieved 0.41 g/L and 2.02 g/L, respectively. Next, modified Mt, as efficient adsorbent, was utilized to toxic anionic dye adsorption from model wastewater. The attraction force between the positive surface charge of modified Mt and the negative charge of RR120 dye molecules leads to the high adsorption capacity. The mostly-known adsorption isotherm models were applied to the experimental data. The obtained data of surfactants adsorption onto Mt, as well as the adsorption data related to RR120 dye removal using modified Mt, were well fitted with the Langmuir isotherm model. The maximum Langmuir capacity for CPCM and ADBAC adsorption by Mt was achieved 183.0 mg/g and 311.8 mg/g, respectively. This amount was found 227.3 mg/g and 243.09 mg/g regarding RR120 adsorption by ADBAC and CPCM-modified Mt, respectively. Also, the hydration inhibitive ability of surfactants was investigated, and the characteristic of them was examined through extensive inhibition evaluation experiments, including settlement, zeta potential, XRD, FTIR, particle size, and SEM analyses.

Surface modified montmorillonite with cationic surfactants: Preparation, characterization, and dye adsorption from aqueous solution

Tunable Schiff's base-cross-linked chitosan composite for the removal of reactive red 120 dye: Adsorption and mechanism study.

Hybrid crosslinked chitosan-epichlorohydrin/TiO2 nanocomposite (CTS-ECH/TNC) was synthesized as an inorganic–organic hybrid nanocomposite bioadsorbent for the removal of reactive red 120 (RR120) dye from aqueous environment. Various analytical techniques were utilized to investigate the surface area, surface morphology, martial crystallinity, elemental composition, amino group content, and fundamental functional group of CTS-ECH/TNC. The impact of key adsorption parameters such as adsorbent dosage (0.02–1.2 g), initial RR120 dye concentration (30–400 mg/L), solution pH (3–12), contact time (0–300 min), and temperature (303–323 K) were explored by batch adsorption process. The adsorption data were well illustrated by pseudo-second order (PSO) kinetic and Langmuir isotherm model. The adsorption process was also found to be a spontaneous and endothermic in nature as indicated by thermodynamic study. The maximum adsorption capacity of CTS-ECH/TNC for RR120 dye was recorded to be 210 mg/g at 303 K. Various types of interactions such as electrostatic attraction, n-π stacking, and H-bonding were responsible for adsorbing RR120 dye molecules on the surface of CTS-ECH/TNC as investigated by tailored adsorption mechanism. Thus, this work introduces CTS-ECH/TNC as promising hybrid biosorbent for the removal of RR120 dye as model of reactive azo dyes from aqueous environment.

Hybrid Crosslinked Chitosan-Epichlorohydrin/TiO2 Nanocomposite for Reactive Red 120 Dye Adsorption: Kinetic, Isotherm, Thermodynamic, and Mechanism Study

Application of macroalgal biomass derived biochar and bioelectrochemical system with Shewanella for the adsorptive removal and biodegradation of toxic azo dye.

Physicochemical modification of chitosan with fly ash and tripolyphosphate for removal of reactive red 120 dye: Statistical optimization and mechanism study.

Sludge from wastewater treatment plant was used as low-cost adsorbent to remove the dye Reactive Red 120 (RR 120) from an aqueous solution. Adsorbents were prepared through thermal (pyrolysis) and chemical treatment (functionalization with HNO3) of sewage sludge. Adsorbents were characterized through physical-chemical and textural analyses. The mesoporous nature of pyrolyzed sludge (PS) and functionalized slugde (FS) influenced the adsorption of RR 120. Moreover, adsorbents surface was rich mainly in carboxylic groups. Batch kinetic experiments were conducted on the statistical design elaborated with central composite rotational design under different pH (3.5–11.5) and temperature (30 °C–60 °C) to achieve the best operational conditions. The response surface methodology (RSM) indicated optimal dye removal efficiency above 94% and 98% at pH and temperature pairs of 3.5/60 °C and 5.4/60 °C for PS and FS, respectively. Kinetics data revealed that pseudo-second-order model better described the adsorption with 2.46 mg g−1 at pH 3.5 for PF and 2.61 mg g−1 at pH 5.4 for FS. Langmuir isotherm model was the best fitted to the adsorption equilibrium data with monolayer maximum adsorption capacities of 14.69 mg g−1 for PS and 46.81 mg g−1 for FS at optimal conditions. The positive ΔH° results indicated an endothermic process (4.73 kJ mol−1 and 8.02 kJ mol−1). Thus, it was concluded that the sewage sludge can be used as an alternative low-cost adsorbent in the removal of RR 120.

Thermal and thermal-acid treated sewage sludge for the removal of dye reactive Red 120: Characteristics, kinetics, isotherms, thermodynamics and response surface methodology design

G. Macioski

Papers

Thermal and thermal-acid treated sewage sludge for the removal of dye reactive Red 120: Characteristics, kinetics, isotherms, thermodynamics and response surface methodology design