Remarkable purification of organic dyes by NiOOH-modified industrial waste residues

Extracting functional materials from industrial waste residues to absorb organic dyes can maximize waste reuse and minimize water pollution. However, the extraordinarily low purification efficiency still limits the practical application of this strategy. Herein, the lamellar NiOOH is in-situ anchored on the industrial waste red mud surface (ARM/NiOOH) as an adsorbent to purify organic dyes in wastewater. ARM/NiOOH adsorbent with high specific surface area and porosity provides considerable active sites for the congo red (CR), thereby significantly enhancing the removal efficiency of CR. Besides, we fit a reasonable adsorption model for ARM/NiOOH adsorbent and investigate its adsorption kinetics. Resultantly, ARM/NiOOH adsorbent can remarkably adsorb 348.0 mg g-1 CR within 5 min, which is 7.91 times that of raw RM. Our work provides a strategy for reusing industrial waste and purifying sewage pollution, which advances wastewater treatment engineering.

Chitosan-Functionalized Hydroxyapatite-Cerium Oxide Heterostructure: An Efficient Adsorbent for Dyes Removal and Antimicrobial Agent

The current research intended to employ a facile and economical process, which is also ecofriendly to transform camel waste bones into novel heterostructure for cleansing of diverse waste waters. The bones of camel were utilized for preparation of hydroxyapatite by hydrothermal method. The prepared hydroxyapatite was applied to the synthesis of cerium oxide-hydroxyapatite coated with natural polymer chitosan (CS-HAP-CeO₂) heterostructure. Being abundant natural polymer polysaccharide, chitosan possesses exceptional assets such as accessibility, economic price, hydrophilicity, biocompatibility as well as biodegradability, therefore style it as an outstanding adsorbent for removing colorant and other waste molecules form water. This heterostructure was characterized by various physicochemical processes such as XRD, SEM-EDX, TEM, and FT-IR. The CS-HAP-CeO₂ was screened for adsorption of various industrially important dyes, viz., Brilliant blue (BB), Congo red (CR), Crystal violet (CV), Methylene blue (MB), Methyl orange (MO), and Rhodamine B (RB) which are collective pollutants of industrial waste waters. The CS-HAP-CeO₂ demonstrated exceptional adsorption against CR dye. The adsorption/or removal efficiency ranges are BB (11.22%), CR (96%), CV (28.22%), MB (47.74%), MO (2.43%), and RB (58.89%) dyes. Moreover, this heterostructure showed excellent bacteriostatic potential for E. coli, that is liable for serious waterborne diseases. Interestingly, this work revealed that the incorporation of cerium oxide and chitosan into hydroxyapatite substantially strengthened antimicrobial and adsorption capabilities than those observed in virgin hydroxyapatite. Herein, we recycled the unwanted camel bones into a novel heterostructure, which assists to reduce water pollution, mainly caused by the dye industries.