Optimization of Cutinase Purification using a Hydrophobic Interaction Membrane Chromatographic Process by Response Surface Methodology

Bioseparation using membrane chromatography: Innovations, and challenges

The resin-based column continues to be the dominant incumbent in bioprocess chromatography. While alternative formats such as membrane-, monolith- and fiber-based chromatography are more visible than before, each still plays minor roles. The reasons for this are complex and some of these are explained in this paper. However, the fact remains that membrane chromatography has come a long way since its early days of development. The main advantage of membrane chromatography continues to be its convection dominant transport mechanism, the resultant benefit being fast and scalable separation. Also, resolution obtained with properly designed devices could be comparable or even better than resin-based chromatography. Significant progress has been made in new membrane development, membrane characterization, device design and novel applications development. A wider range of new membrane matrices, ligands, and ligand-matrix linking chemistries are now available. New membrane modules, formats, and process configurations have also helped improve membrane performance. However, some significant challenges still exist, and these need to be addressed if membrane chromatography is to become more mainstream in the field of bioprocessing. Also, membrane chromatography has significant potential for application in analytical separations and this space has hardly been explored. In this paper, the advances in the areas of membrane preparation, device design and process development are reviewed. A high-level cost analysis is presented and the role of process design in membrane chromatography is discussed.

Microalgae-based advanced municipal wastewater treatment for reuse in water bodies

Reuse of secondary municipal effluent from wastewater treatment plants in water bodies could effectively alleviate freshwater resource shortage. However, excessive nutrients must be efficiently removed to prevent eutrophication. Compared with other means of advanced wastewater treatment, microalgae-based processes display overwhelming advantages including efficient and simultaneous N and P removal, no requirement of additional chemicals, O₂ generation, CO₂ mitigation, and potential value-added products from harvested biomass. One particular challenge of microalgae-based advanced municipal wastewater treatment compared to treatment of other types of wastewater is that concentrations of nutrients and N:P ratios in secondary municipal effluent are much lower and imbalanced. Therefore, there should be comprehensive considerations on nutrient removal from this specific type of effluent. Removal of nutrients and organic substances, and other environmental benefits of microalgae-based advanced municipal wastewater treatment systems were summarized. Among the existing studies on microalgal advanced nutrient removal, much information on major parameters is absent, rendering performances between studies not really comparable. Mechanisms of microalgae-based nitrogen and phosphorus removal were respectively analyzed to better understand advanced nutrient removal from municipal secondary effluent. Factors influencing microalgae-based nutrient removal were divided into intrinsic, environmental, and operational categories; several factors were identified in each category, and their influences on microalgal nutrient removal were discussed. A multiplicative kinetic model was integrated to estimate microalgal growth-related nutrient removal based majorly on environmental and intrinsic factors. Limitations and prospects of future full-scale microalgae-based advanced municipal wastewater treatment were also suggested. The manuscript could offer much valuable information for future studies on microalgae-based advanced wastewater treatment and water reuse.