Removal of methylene blue dye using rice husk, cow dung and sludge biochar: Characterization, application, and kinetic studies.

Environmental pollution associated with the discharge of textile industries is becoming a global concern. There is an imperative need for developing efficient, environmentally friendly, and cost-effective techniques for treating the wastewater containing dyes. Bioremediation of dyes is a fascinating approach to treat the textile effluents as it offers many advantages over the conventional treatment techniques. This review critically evaluates the latest advancements in applications of bioremediation techniques for the removal of various dyes from wastewater. The applications of various microorganisms such as bacteria, algae, fungi, yeast, and enzymes for the uptake of dyes are portrayed in detail. The current advancements in the bioremediation of textile effluents, research opportunities, challenges, and future outlook are emphasized. It also highlights the progress in bioremediation of dyes using bioreactors and microbial fuel cells. This review is beneficial in understanding the current status of bioremediation in water purification and accelerating the research focusing the role of bioremediation in water purification applications in future.

Bioremediation of dyes: Current status and prospects

Surface treated acid-activated carbon for adsorption of anionic azo dyes from single and binary adsorptive systems: A detail insight.

Enzyme immobilization has been developing since the 1960s and although many industrial biocatalytic processes use the technology to improve enzyme performance, still today we are far from full exploitation of the field. One clear reason is that many evaluate immobilization based on only a few experiments that are not always well-designed. In contrast to many other reviews on the subject, here we highlight the pitfalls of using incorrectly designed immobilization protocols and explain why in many cases sub-optimal results are obtained. We also describe solutions to overcome these challenges and come to the conclusion that recent developments in material science, bioprocess engineering and protein science continue to open new opportunities for the future. In this way, enzyme immobilization, far from being a mature discipline, remains as a subject of high interest and where intense research is still necessary to take full advantage of the possibilities.

Is enzyme immobilization a mature discipline? Some critical considerations to capitalize on the benefits of immobilization.

In the last 3 years alone, over 10,000 publications have appeared on the topic of dye removal, including over 300 reviews. Thus, the topic is very relevant, although there are few articles on the practical applications on an industrial scale of the results obtained in research laboratories. Therefore, in this review, we focus on advanced oxidation methods integrated with biological methods, widely recognized as highly efficient treatments for recalcitrant wastewater, that have the best chance of industrial application. It is extremely important to know all the phenomena and mechanisms that occur during the process of removing dyestuffs and the products of their degradation from wastewater to prevent their penetration into drinking water sources. Therefore, particular attention is paid to understanding the mechanisms of both chemical and biological degradation of dyes, and the kinetics of these processes, which are important from a design point of view, as well as the performance and implementation of these operations on a larger scale.

https://www.mdpi.com/1420-3049/26/4/870/pdf

Recent Achievements in Dyes Removal Focused on Advanced Oxidation Processes Integrated with Biological Methods

A novel comparative study of modified carriers in moving bed biofilm reactor for the treatment of wastewater: Process optimization and kinetic study.

Biodegradation of Congo red dye in a moving bed biofilm reactor: Performance evaluation and kinetic modeling.

Collective removal of phenol and ammonia in a moving bed biofilm reactor using modified bio-carriers: Process optimization and kinetic study.

The wastewater containing the azo dye is a global environmental challenge among researchers. In this study, an effort has been made to use a modified carrier (i.e., low-density polyethylene–polypropylene(LDPE-PP)) to remove the Congo red (CR) dye from synthetic wastewater in a moving bed biofilm reactor (MBBR). The effect of CR dye concentration (25 to 300 mg/L), hydraulic retention time (HRT) (12 to 96 h) under the batch mode, and inlet loading rate (ILR) (40 to 320 mg/L day) under the continuous mode were examined. The highest removal efficiency (RE) and elimination capacity (EC) of CR dye were obtained as 99.2% and 214.4 mg/L day, respectively. Three models, namely first-order, Grau second-order, and modified Stover–Kincannon (S–K) were applied to study the kinetic aspects. The highest correlation coefficient ( R 2 ) was obtained for the modified S–K model, and the saturation constant ( K B ) and maximum substrate removal rate ( U m a x ) were estimated as 0.67 g/L day and 0.71 g/L day, respectively. The proposed kinetic equations can predict the effluent concentration and estimate the bioreactor volume to scale up the process.

Moving bed biofilm reactor with immobilized low-density polyethylene–polypropylene for Congo red dye removal

In this work, Bacillus flexus GS1 IIT (BHU) as free and immobilized cells on low-density polyethylene (LDPE) were used to remove 4-Chlorophenol (4-CP) from the synthetic wastewater. The effect of the process variables, namely process time, pH, temperature, and 4-CP concentration, were optimized and obtained as 7.0 days, 7.0, 30 °C, and 50 mg/L, respectively. At optimum conditions, the maximum removal efficiencies (REs) were obtained to be 90.34 and 78.12% for the immobilized and free cells, respectively, at 50 mg/L concentration of 4-CP. Furthermore, a packed bed bioreactor (PBBR) was continuously operated for 60 days with the immobilized LDPE. The maximum RE of 82.4% and elimination capacity (EC) of 29.6 mg/L/d were obtained at 50 mg/L of the initial concentration of 4-CP. The growth kinetic parameters for Bacillus sp. were obtained to be: μ m a x : 0.205 h−1, K s : 3.3 mg/L, K i : 220 mg/L for Aiba model; μ m a x : 0.197 h−1, K s : 1.4 mg/L, K i : 220 mg/L for Edward model; and m u m a x : 0.185 h−1, K s : 1.6 mg/L, K i : 200 mg/L for Andrew-Haldane model, respectively.

Ganesh Swain

Papers

A novel comparative study of modified carriers in moving bed biofilm reactor for the treatment of wastewater: Process optimization and kinetic study.

Biodegradation of Congo red dye in a moving bed biofilm reactor: Performance evaluation and kinetic modeling.

Collective removal of phenol and ammonia in a moving bed biofilm reactor using modified bio-carriers: Process optimization and kinetic study.

Moving bed biofilm reactor with immobilized low-density polyethylene–polypropylene for Congo red dye removal

Removal of 4-Chlorophenol by Bacillus flexus as free and immobilized system: Effect of process variables and kinetic study