Phyto-Extract-Mediated Synthesis of Silver Nanoparticles Using Aqueous Extract of Sanvitalia procumbens, and Characterization, Optimization and Photocatalytic Degradation of Azo Dyes Orange G and Direct Blue-15

Green synthesis of silver nanoparticles (AgNPs) employing an aqueous plant extract has emerged as a viable eco-friendly method. The aim of the study was to synthesize AgNPs by using plant extract of Sanvitalia procumbens (creeping zinnia) in which the phytochemicals present in plant extract act as a stabilizing and reducing agent. For the stability of the synthesized AgNPs, different parameters like AgNO3 concentration, volume ratios of AgNO3, temperature, pH, and contact time were studied. Further, AgNPs were characterized by UV–visible spectroscopy, FT-IR (Fourier Transform Infrared Spectroscopy), XRD (X-ray Diffraction), SEM (Scanning Electron Microscopy), and EDX (Energy Dispersive X-ray Spectrometer) analysis. FT-IR analysis showed that the plant extract contained essential functional groups like O–H stretching of carboxylic acid, N–H stretching of secondary amides, and C–N stretching of aromatic amines, and C–O indicates the vibration of alcohol, ester, and carboxylic acid that facilitated in the green synthesis of AgNPs. The crystalline nature of synthesized AgNPs was confirmed by XRD, while the elemental composition of AgNPs was detected by energy dispersive X-ray analysis (EDX). SEM studies showed the mean particle diameter of silver nanoparticles. The synthesized AgNPs were used for photocatalytic degradation of Orange G and Direct blue-15 (OG and DB-15), which were analyzed by UV-visible spectroscopy. Maximum degradation percentage of OG and DB-15 azo dyes was observed, without any significant silver leaching, thereby signifying notable photocatalytic properties of AgNPs.

A Recent Study on Remediation of Direct Blue 15 Dye Using Halloysite Nanotubes

A set of lab-scale experiments were designed and conducted to remedy Direct Blue 15 (DB15) dye using nontoxic halloysite nanotubes (HNT) with the view to be utilized in a textile industrial effluent (TIE). The DB15 adsorbed-HNT “sludge” was used as a reinforcing agent and plastic waste to fabricate the composite. To advance the knowledge and further understand the chemical phenomena associated with DB15 adsorption on HNT, different factors like pH value, adsorbate initial concentration, adsorbent dosage, and temperature on the composite were affected experimentally tested. To estimate the adsorption capacity of HNT, nine isotherm models were applied, and it was identified that the Brouers–Sotolongo adsorption isotherm model represented the best accuracy for predicting the adsorption behavior of the HNT. Likewise, the pseudo-second-order reaction was the predominant mechanism for the overall rate of the multi-step dye adsorption process. Additionally, it was demonstrated that the mass transfer during the process is diffusion-controlled, and thermodynamic assessments showed that the process is physisorption.

Novel Fe3O4–poly(methacryloxyethyltrimethyl ammonium chloride) adsorbent for the ultrafast and efficient removal of anionic dyes

The Fe3O4–pDMC magnetic adsorbent was synthesized, and the mechanism of its rapid and efficient removal of two anionic dyes (acid orange 7 and direct blue 15) was studied.

Eco-friendly dyeing of cellulosic fabric using Direct Red 28 and Direct Blue 15 dyes

<p>Sustainability in textiles is now a day’s key demand of consumers and traders, where the process with zero effluent emission or less emission has been considered for aim to utilize the ecofriendly process in direct dyeing of cotton to minimize effluent load. For this purpose, variable amount of Table salt and Glauber salt has been used to achieve maximum exhaustion during direct cotton dyeing. Different dyeing variables have been employed, shade made at the optimum conditions were assessed according to ISO standards. It has been found that 3g/100mL of table salt for Direct dyeing of cotton using 40mL of DR 28 (8pH) at 65oC for 45 min, whereas using 40mL of DB 15 (8pH) for dyeing of cotton at 65 °C for 45min containing 3g/100mL of Glauber slat has given acceptable color characteristics. The reduction in dyeing variable using low salt amount has proved that this method is cost, time and energy efficient process, which can be utilized for dyeing of natural fabrics using various classes of dyes to obtain sustainable textile products.</p>