In order to control the negative impacts of dyes on living organisms, several techniques and methodologies have been developed for their removal from industry effluents and other water bodies.

This is an Open Access Article. It is published by Elsevier under the Creative Commons Attribution 3.0 Unported Licence (CC BY). Full details of this licence are available at: http://creativecommons.org/licenses/by/3.0/A completely new method of extraction of amoxicillin using solubilisation by mixed reverse micelles was proposed and the optimal conditions for the process were found. Mixed AOT-TWEEN 85 reverse micelles were used for the first time as a new approach for extraction of amoxicillin. The effects of different process variables such as AOT-TWEEN 85 molar fractions, total surfactant concentration, pH of aqueous feed solution and potassium chloride concentration during forward extraction; stripping aqueous phase pH, potassium chloride (KCl) concentration and extraction time during backward extraction were investigated and the optimal conditions were found for all mentioned parameters. With the aid of response surface methodology, the optimum conditions for forward extraction are identified as (i) 5.5:1 molar ratio of AOT/TWEEN 85, (ii) total surfactant concentration 102.57. g/L, (ii) pH 1.90, and (vi) KCl concentration 8.54. g/L. The percentage of amoxicillin solubilised in isooctane was 95.54% under these optimal conditions. On the other hand, the optimum conditions for backward extraction are identified as (i) stripping aqueous phase pH 6.58, (ii) KCl concentration 11.02. g/L, and (iii) extraction time 15. min. Under these optimal conditions, the percentage of amoxicillin recovered was 90.79%. AOT/TWEEN 85 mixed surfactant system shows a significant advantage of saving the amount of surfactant for forward extraction. The addition of non-ionic surfactant helps to preserve natural function/activity of antibiotics as compared with a pure AOT surfactant used. The optimum conditions were also found for a backward recovery of amoxicillin

Currently, there is increasing interest on low cost and commercially available materials for the adsorption of heavy metals. The vital benefits of adsorption technologies are its potential in reducing the concentration of heavy metal ions using low-cost adsorbent materials. Fruit peel wastes (FPW) are readily available in abundance. Furthermore, it has a high potential as a sustainable adsorbent due to its large quantity of lignocellulosic materials. Realizing this potential, there are many studies on various fruit peels waste adsorbents used in the removal of Pb (II), Cu (II) and Cd (II) ions from wastewater. However, there is no comprehensive review of these adsorbents, especially on the factors that influenced the adsorption capacity. Hence, this review aims to study on the various fruit peels waste adsorbents and the factors by comparing the metal binding capacities, metal removal performances, sorbent dosage, optimum pH, temperature, initial concentration and contact time. Finally, the adsorption mechanisms were also discussed.

Reverse micelles extraction of erythromycin and amoxicillin were carried out using the novel Sophorolipids biosurfactant. By replacing commonly used chemical surfactants with biosurfactant, reverse micelle extraction can be further improved in terms of environmental friendliness and sustainability. A central composite experimental design was used to investigate the effects of solution pH, KCl concentration, and sophorolipids concentration on the reverse micelle extraction of antibiotics. The most significant factor identified during the reverse micelle extraction of both antibiotics is the pH of aqueous solutions. Best forward extraction performance for erythromycin was found at feed phase pH of approximately 8.0 with low KCl and sophorolipids concentrations. Optimum recovery of erythromycin was obtained at stripping phase pH around 10.0 and with low KCl concentration. On the other hand, best forward extraction performance for amoxicillin was found at feed phase pH around 3.5 with low KCl concentration and high sophorolipids concentration. Optimum recovery of erythromycin was obtained at stripping phase pH around 6.0 with low KCl concentration. Both erythromycin and amoxicillin were found to be very sensitive toaqueous phase pH and can be easily degraded outside of their stable pH ranges.

This article discusses the application of mixed reverse micelles in downstream processing of antibiotics. Purification and recovery processes for antibiotics in downstream processing are major expenses, about 70% of the total cost of production, giving them a significant impact on manufacturing cost. Moreover, there are a number of challenges and difficulties in the separation process requirements for antibiotics, since the mixture is quite complex, with broth, hazardous solvents, by-products, intermediate material, and impurities; in addition, antibiotics are easy to denature. Therefore, the development of effective separation techniques is required to produce high-purity of biomaterials. The use of reverse micelles is thought to be among the most promising due to the process's high selectivity and efficiency. Most studies on reverse micelle extraction technology have been performed by using anionic surfactant sodium bis (2-ethyl-1-hexyl) sulfosuccinate (AOT). However, the activities of antibiotics hosted in this type of surfactant have a significant effect due to the strong electrostatic and hydrophobic interaction between antibiotic and surfactant molecules. Due to these problems many alternatives have been developed recently, and reverse micelles have high potential in the purification of biomolecules. Therefore, this review discusses the ability of mixed ionic-nonionic reverse micelles to provide a safe microenvironment for antibiotics by maintaining the strength of attraction between the reverse micelle molecule and the antibiotic while avoiding the denaturation of the antibiotic. The article highlights the potential of mixed ionic-nonionic reverse micelle technology as a tool of antibiotic recovery from various mediums.