Novel environmental method for enhanced biodegradation of contaminated wastewater via immobilizing nanoparticles on a new bacterial strain isolated industrial textile.

Biological processes comprising bacteria, fungi, yeast, and algae received increasing interest for dye degradation due to their cost-effectiveness and eco-friendly nature. Hence, the current study aims to investigate the ability of the photocatalytic performance of N-S co-doped anatase TiO2 (NSTO) nanoparticles immobilized on isolated industrial textile bacteria (ITB) for degradation of basic blue 41 (BB 41). To prove the effect of improving the surface area of NSTO, NSTO also was immobilized on glass balls (NSTO-GB). NSTO nanoparticles were synthesized using sol-gel methods, and characterization of NSTO and NSTO-GB were measured using SEM, TEM, XPS, and DLS analysis. The results showed that the average size of NSTO was 50-60 nm. Moreover, the morphology and surface microstructure of ITB and ITB-NSTO were determined by the SEM, XPS technique. According to the results, ITB has a rod structure, NSTO nanoparticles are placed on the surface of ITB. However, NSTO was attached to the surface of ITB with the hydroxyl group. The ITB-NSTO indicated a higher BB 41 degradation yield (99%) than pure NSTO (65%) and ITB (74%). The effect of different factors was evaluated on biodegradation by ITB-NSTO. The high biodegradation was obtained in ITB (10 mg), NSTO (50 mg), BB41 (50 ppm), and pH 11. The GC-Mass, LC-Mass, and FT-IR analysis, which monitored the BB 41 degradation efficiency, proved the degradation efficiency by 99%. In the following, the toxicities of BB 41 solution before and after degradation were accessed through the brine shrimp lethality assay (BSLA) and seed germination assay, which displayed a considerable reduction in BB 41 after degradation. Toxicity results exhibited that ITB-NSTO has potential for industrial application.

S, N co-doped carbon quantum dots/TiO2 nanocomposite as highly efficient visible light photocatalyst.

In this paper, we report on the preparation of S, N co-doped carbon quantum dots (CQDs)/TiO2 nanocomposite using a hydrothermal process where S, N-CQDs were concurrently synthesized and anchored to the surface of the TiO2. The prepared nanocomposite was carefully characterized to identify the morphology and structure, crystallinity, chemical composition and optical properties. The photocatalytic activity of the nanocomposite was investigated for degradation of acid red 88 (AR88) under visible light irradiation. The capability of the S, N-CQDs/TiO2 nanocomposite to remove AR88 (77.29%) was higher than that of pure TiO2 (23.7%). In order to determine the influencing factors on the photocatalytic activity of the prepared nanocomposite, we studied various contents of the photocatalyst, the effect of pH and the content of H2O2. Further investigations were conducted to reveal the mechanism of photocatalytic degradation using radical scavenging agents. The stability and reusability of the S, N-CQDs/TiO2 photocatalyst was tested in four reaction cycles (870 min) which showed a 25% loss of photoactivity after the fourth photocatalytic reaction.