Performance of wastewater sludge modified with zinc oxide nanoparticles in the removal of methylene blue from aqueous solutions

Abstract

A B S T R A C TThe presence of chromogenic substances in water can potentially be carcinogenic and mutagenic, and thus, it may be hazardous to public health. This study was carried out with the objective of investigating the feasibility of using wastewater sludge, modified with zinc oxide nanoparticles, in the removal of the methylene blue (MB) dye from aqueous solution. The stabilization of nanoparticles onto the sludge was performed using the thermal method in order to increase the active adsorption surface. The effects of the operational parameters (including pH, contact time, MB dye concentration, and adsorbent dosage) on the adsorption of MB by the modified sludge were studied in batch mode. The sludge coated with zinc oxide nanoparticles had higher MB dye removal efficiency (%) than that of raw sludge. The MB adsorption amount (Q e ) increases with a reduction in the adsorbent dosage, an increase in pH, and an increase in the initial concentration of the MB dye. At equilibrium, the amount of MB dye adsorbed onto sludge coated with zinc oxide nanoparticles was 6.6 mg/g, while the amount of adsorbed MB dye onto raw sludge was 2.9 mg/g. The adsorption reached equilibrium after 120 min and the adsorption data fitted the Langmuir isotherm model (R 2 = 0.99). The modification of sludge with zinc oxide nanoparticles can provide an appropriate substance to function as the adsorbent in the removal of MB dye from aqueous solution.

Structurally diverse coordination compounds of zinc as effective precursors of zinc oxide nanoparticles with various morphologies

“…Zinc oxide nanoparticles, the study of which has been described in this work, can be successfully utilized as vulcanization activators in the rubber industry, UV filters in sunscreen products, antibacterial agents in dermatological drugs, anode materials in lithium‐ion batteries, coating materials for orthopaedic and dental implants, or as catalysts in water purification from multiple pollutions (e.g. from potentially carcinogenic and mutagenic substances like methylene blue) …”

Porous PVA/Zn–Fe–Mn oxide nanocomposites: methylene blue dye adsorption studies

“…From the Langmuir model, the MBD removal efficiency of the optimized nanocomposites was determined to be 7.75 mg g . 1 The PSO adsorption-reaction kinetics model fits well. These adsorption process tests are showing the domination of monolayer/chemisorption type of adsorption.…”

“…The adsorption kinetics study was performed using the adsorbate-adsorbent contact time of 10,30,50,70,90,110,130, and 150 min. Furthermore, the adsorption isotherm test was conducted using MBD concentration of 1,5,10,15,20,25,30, and 35 mg l . 1 For a proper understanding of the adsorption process, the adsorption isotherm models (equations (3)-(8)) and adsorption kinetics models (equations (9)-(13)) were used [21,22].…”

“…Nowadays, industries are using different dyes to dye manufactured products. The dumping of those pollutants can cause cancer and also genotoxic [1]. For a year, among several removal techniques, depending on the surface area and stability, metal oxide nanomaterials are getting attention.…”

Microwave assisted synthesis of ZnO nanoparticles for lighting and dye removal application

“…for the extraction of dyes from contaminated water [3][4][5]. It was reported that ZnO is an efficient material for dye adsorption [6][7]. It is also a gifted semiconductor material due to its direct wide energy band gap (3.37 eV) with a large exciton binding energy (60 meV) at ambient temperature [7][8][9].…”