• Nanotechnology has opened up new possibilities in bioremediation and biotechnology fields, like extends to membrane technology, advanced oxidation processes, and biosensors. • Nanoparticles (NPs) can be generated in various shapes and sizes through physical, chemical, or biological means. Conventional methods using potent reducing agents lead to energy inefficiency, reduced yields, high costs, and environmental harm. • Microorganisms (bacteria, fungi, yeast, algae) and plants offer alternative pathways for NP synthesis. • Sustainable nanoparticle synthesis methods are preferred to align with environmentally friendly principles. • This review provides an overview of environmentally friendly NP synthesis using plant extracts, focusing on simplicity, cost-effectiveness, and environmentally beneficial applications.

The bacterium Pseudomonas stutzeri SPM-1, obtained from textile wastewater dumping sites of Surat, Gujarat was studied for the degradation of the textile azo dye Procion Red—H3B. The optimization was carried on the phenanthrene enrichment medium followed by exposing it to variable environmental factors and nutritional sources. The complete decolorization of dye (50 mg/L) happened within 20 h of incubation at pH 8 and temperature 32 ± 0.2 °C under microaerophilic conditions. Decolourization was monitored with the shifting of absorbance peak in UV–Vis spectrophotometry and HPLC analysis. The physicochemical studies of effluent before and after the treatment revealed 85%, 90%, and 65% decline in BOD, COD, and TOC levels. The strain showed significant activities of azoreductase (95%), laccase (76%), and NADH-DCIP reductase (88%) at 12 h, 10 h, and 8 h of growth respectively indicating evidence for reductive cleavage of the dye. The changes in the functional groups were confirmed by the presence of new peaks in FT-IR data. GC–MS analysis helped in recognizing the degraded dye compounds thus elucidating the proposed pathway for degradation of Procion Red—H3B. The potential of the bioremediation process was concluded by a phytotoxicity test using two plants, Vigna radiata and Cicer arietinum. Our study demonstrates that the strain Pseudomonas stutzeri SPM-1 has rapid decolorization efficiency and holds a noteworthy perspective in industrial application for textile wastewater treatment.

Magnetic nanoparticles have gained huge importance in the last ten years. They have found tremendous applications in the field of medicine, electronics, and environmental cleanup. The synthesis of amorphous iron oxide nanoparticles (AIONPs) is expensive making its applications highly overpriced. This research study reports the synthesis of AIONPs from waste incense sticks ash (ISA) in two steps. The first step is the recovery of ferrous fractions from ISA, followed by concentrated HCl treatment of magnetic fraction along with ultrasonication. And the second step includes treatment of ferrous‐rich leachate with sodium hydroxides. The size of synthesized AIONPs varied from 40‐90 nm and were highly aggregated due to the formation of large clumps. Cytotoxicity of synthesized AIONPs was determined on a normal human lung (BEAS‐2B) cell line by using an MTT assay. Data showed that AIONPs induced cell toxicity in a dose‐dependent manner. The particles were mainly spherical to rod‐shaped and highly aggregated, it was confirmed by the microscopy analysis. The Fourier transform infrared (FT‐IR) and Raman spectroscopy revealed the Fe‐O, Si‐O‐Al as major functional groups in the AIONPs, while X‐ray diffraction (XRD) revealed the amorphicity and physical property measurement system (PPMS) revealed the magnetic strength of the synthesized AIONPs. Finally, the AIONPs particles were applied for the remediation of Congo red dye from the wastewater by the adsorption method, and about 72% removal was achieved after one hour. The utilization of such ISA waste, for the synthesis of value‐added minerals and their utilization for environmental cleanup, makes this whole process cost‐efficient and environment‐friendly.

Textile effluent generated during the dyeing process of textiles is a huge supplier to water toxicity all over the world. Textile dyes are the main toxic component found in the effluent sample which is difficult to treat. A bacterial consortium capable of decolourizing and degrading the textile dye acid orange is reported in this research article. The bacterial consortium was identified by 16 S rDNA sequence and phenotypic characteristics. It is composed of four strains i.e., Pseudomonas stutzeri (MW219251), Bacillus tequilensis (MW110471), Bacillus flexus (MW131645), Kocuria rosea (MW132411). The consortium was able to cause decolorization of azo dye acid orange (30 mg/L) in 23 h, when kept under static laboratory conditions. The optimal pH and temperature for color removal were pH 7.5 and 32°C, respectively. The decolorization of dye before and after was checked by UV-Visible absorption spectra. This gives evidence that decolorization was caused due to biodegradation. This was further assured by studying the reduction of biological oxygen demand (BOD₅ (96%), chemical oxygen demand (COD) (79%), and TOC (total organic carbon) (54%) of the bacterial-treated water sample. The Fourier transform-infrared spectroscopy (FT-IR) spectroscopy and gas chromatography-mass spectroscopy (GC-MS) results confirmed the mineralization of the dye. The results indicate the effectiveness of the bacterial consortium SPB92 in the biodegradation of acid orange dye. This demonstrates that the consortium has immense potential and will serve as an important contributor to the treatment of textile wastewater.