Rapid Degradation of Rhodamine B via Poly(dopamine)-Modified Membranes with Silver Nanoparticles

Dye Removal Ability of Pure and Doped Graphitic Carbon Nitride

Background:

Rapid escalation in textile, paper, pesticides, pharmaceuticals and several other chemical based manufacturing industries due to amplification in human requirements have proportionately contributed to the extreme contamination of water ecosystem, resulted from the discharge of toxic pollutants from industries. Effluents from textile industries are comprised of coloured dyes like Rhodamine B, Methyl Orange, Methylene Blue and phenolic compounds which deserve special mention owing to their non-biodegradable, carcinogenic and severe detrimental nature. Urgent needs to ameliorate this fast declining environmental situation are of immense necessity in current scenario.

Objectives:

Objectives: In this regard, graphitic carbon nitride (GCN) is a distinguished material for water purification-based applications because of its exclusive characteristics making it highly prospective for degradation of toxic dyes from water by catalysis and adsorption techniques. GCN has been a material of conspicuous interest in recent times owing to its two dimensional sheets like structure with favourable surface area, and cost-effective synthesis approaches along with high production yield. This article presents a detail study of different aspects of GCN as a material of potential for water purification. Through extensive literature survey it has been shown that GCN is an effective material to be used in the fields of application. Several effective procedures like catalysis or adsorption for removal of dyes from water have been discussed with their basic science behind.

Conclusions:

This systematic effort shows that GCN can be considered to be one of the most efficient water purifier with further advantages arising from its easy and cost effective large scale synthesis.

Fabrication of Stable MIL-53(Al) for Excellent Removal of Rhodamine B

Adsorptive purification of organic dyes in wastewater is significant to protect the water environment. Herein, MIL-53(Al) was successfully fabricated through a facile and versatile solvothermal strategy. The stability of MIL-53(Al) under high temperature, acid, base, and peroxide conditions was investigated. The porous MIL-53(Al) had high chemical stability, and the thermal stability reached up to 500 °C, which provided a good foundation for dye removal. MIL-53(Al) showed excellent adsorption performance. The maximum adsorption capacity of MIL-53(Al) for rhodamine B (RhB) can reach 1547 mg g^-1 under 303 K, and the corresponding removal efficiency exceeded 90% at the equilibrium time (120 min). The Langmuir model and pseudo-second-order model can well fit RhB adsorption on MIL-53(Al). Thermodynamic study and activation energy values over the range of 298-323 K revealed that the adsorption of RhB was a spontaneous and endothermic physical process in nature. The batch experimental results, X-ray photoelectron spectroscopy (XPS), and Fourier-transform infrared (FTIR) spectroscopy analyses suggested that the hydrogen bonding and electrostatic interactions between the hydroxyl/carboxyl groups of MIL-53(Al) and RhB were the primary adsorption mechanisms. Besides, MIL-53(Al) had a higher selectivity to RhB than the coexisting ions in aqueous solution and a superior adsorption performance after five cycles.