Adsorptive performance of a mixture of three nonliving algae classes for nickel remediation in synthesized wastewater

Abstract

Purpose The present study provided a comprehensive description regarding the application of a mixture of three nonliving classes of algae as a promising and inexpensive biosorbent for removing toxic nickel (Ni(II)) ions from the aqueous medium. Methods The biosorption process was tested by varying several experimental parameters such as pH (2-8), contaminant concentration (20-300 mg/L), biosorbent content (0.2-2 g/100 mL), and temperature (20-40 °C). In addition, the competition effects of the presence of Pb(II), Cu(II), and Zn(II) ions on the Ni(II) removal efficiency was studied by varying their concentrations from 30 to 40 mg/L. ResultsThe microscopic analysis of algae demonstrated that the used biosorbent consisted mainly of Chrysophyta (80%), Chlorophyte (14%), and Cyanophyta (6%). Results demonstrated that these environmental parameters influenced the removal efficiency with a different degree and there was no stable effects rank at conditions under examination. FT-IR and SEM analysis revealed that the biosorbent surface consists of many strong and active groups of negative valences such as hydroxyl and carboxyl groups, thus exhibiting several morphological properties of interest. Further, it was found that the Temkin model best fitted the isotherm biosorption data. The kinetic study showed that the Ni(II) biosorption was rapid within first 20 min of reaction time, thereby following a pseudo-second-order model, which in turn demonstrated a chemisorption process of Ni(II) ions reaction with the biosorbent binding sites. Also, the thermodynamic study suggested that the biosorption process of Ni(II) onto algal biomass was a spontaneous and endothermic in nature. The maximum uptake of Ni(II) was 9.848 mg/g under optimized conditions and neutral environment. Conclusions Thus, this significant finding suggested a favorable and eco-friendly treatment mechanism for removal of Ni(II) ions from aqueous medium via biosorption onto the used mixture of nonliving algal biomass.

Removal of Tetracycline from Wastewater Using Circulating Fluidized Bed

“…The liquid phase residence time decreases with a UL increase, (breakthrough time for 18, 21, and 24 l/hr flowrate was 380, 340, and 300 min respectively) thus adsorption time reduced and higher pollutant concentration noticed in raffinate stream. These results agree with that obtained by [26]. 18 l/hr.…”

“…This is attributed to a high concentration difference (driving force for adsorption) between in liquid and solid phase also, may increase solute mass transfer rate to contact adsorbent active free sites. If the initial antibiotic concentration is high, faster bed saturation occurring and the slope of the breakthrough curve is higher, so 10 ppm initial antibiotic solution concentration was chosen as the best value for the next experiments [26], [27]. Fig.…”

Adsorption performance of an amine-functionalized MCM–41 mesoporous silica nanoparticle system for ciprofloxacin removal in a batch system

“…Under these conditions, the attraction between MCM-41-NH2 and CIP molecules, and thus the adsorption of the CIP molecules on MCM-41-NH2 are high because their surfaces have dissimilar charges. These results are consistent with those obtained in similar previously reported studies (Parsa et al, 2016, Mohammed et al, 2019. Based on these results, it can be inferred that the adsorption of CIP on MCM-41-NH2 will be optimum at neutral pH.…”

“…Based on these results, it can be inferred that the adsorption of CIP on MCM-41-NH2 will be optimum at neutral pH. From the water and wastewater treatment and cost prespectives, a treatment that can be performed at neutral or near neutral pH is favorable because it normally does not require pH adjustment in advance (Mohammed et al, 2019, Khodadadi et al, 2019.…”

Recent trends in Ni(II) sorption from aqueous solutions using natural materials

“…Several authors have complemented the characterisation of the materials tested with determination of the pH of point zero charge (pHpzc). For a mixture of three nonliving algae classes the authors determined that pHpzc was approximately 5.8, which indicates that beyond this pH value the surface of this biomass will be negatively charged (Mohammed et al 2019). pH above 8 was excluded from effect study to prevent removal of Ni(II), by other mechanisms like precipitation.…”