A synergistic approach combining computational fluid dynamics simulation with hydrolysis-acidification for dye wastewater treatment.

Wastewater treatment is effectively conducted using anaerobic biological methods. Nevertheless, the efficiency of these methods can be hindered by challenges like short-circuits and dead zones, particularly in treating persistent contaminants. This work utilized computational fluid dynamics (CFD) simulations to enhance water distribution, ensuring uniform interactions between solid and liquid phases, and thus mitigating issues related to short-circuits and dead zones. Such enhancements notably amplified the anaerobic biological process's efficiency. Furthermore, dye biodegradability was improved through the application of the hydrolysis acidification technique. Optimal hydraulic retention time for the hydrolysis-acidification reactor, established at 9 h, was determined via sludge cultivation and domestication for stable operation. During stable operation, an elevation in effluent volatile fatty acids was observed, alongside a COD removal rate fluctuating between 15% and 29%. Approximately 50% was noted as the rate of color removal. Simultaneously, a noticeable decrease in effluent pH occurred, with total nitrogen removal approximating 8%. An estimated BOD5/COD ratio of 0.32 was recorded. The incorporation of microbial agents led to an enhanced COD removal, ranging from 28% to 33%, thereby stabilizing the effluent BOD5/COD ratio at around 0.35. This research highlights the advantages of optimizing water distribution in anaerobic reactors, particularly when combined with hydrolysis-acidification techniques, effectively addressing issues of short-circuits and dead zones.

Innovative treatment of industrial effluents through combining ferric iron and attapulgite application.

The escalation of industrial activities has escalated the production of pharmaceutical and dyeing effluents, raising significant environmental issues. In this investigation, a hybrid approach of Fenton-like reactions and adsorption was used for deep treatment of these effluents, focusing on effects of variables like hydrogen peroxide concentration, catalyst type, pH, reaction duration, temperature, and adsorbent quantity on treatment effectiveness, and the efficacy of acid-modified attapulgite (AMATP) and ferric iron (Fe(III))-loaded AMATP (Fe(III)-AMATP) was examined. Optimal operational conditions were determined, and the possibility of reusing the catalysts was explored. Employing Fe3O4 as a heterogeneous catalyst and AMATP for adsorption, CODCr was reduced by 78.38-79.14%, total nitrogen by 71.53-77.43%, and phosphorus by 97.74-98.10% in pharmaceutical effluents. Similarly, for dyeing effluents, Fe(III)-AMATP achieved 79.87-80.94% CODCr, 68.59-70.93% total nitrogen, and 79.31-83.33% phosphorus reduction. Regeneration experiments revealed that Fe3O4 maintained 59.48% efficiency over three cycles, and Fe(III)-AMATP maintained 62.47% efficiency over four cycles. This work offers an economical, hybrid approach for effective pharmaceutical and dyeing effluent treatment, with broad application potential.