Effects of Flocculant Concentration and Temperature on the Membrane Separation Process in Microalgal Suspensions

Abstract

By using different flocculant concentrations and temperatures with a tannin‐based flocculant, chitosan, and ferric chloride, the performance of a combined flocculation and membrane separation process in microalgal suspensions was evaluated. Permeate flux experiments were conducted for 30 min, and the effects of the flocculant concentration and temperature were analyzed. The zeta potential of the culture with and without flocculant approached zero with increasing temperature, in favor of microalgal cell agglomeration. At 40 °C, crossflow microfiltration showed a 27 % improvement in the permeate flux compared to 20 °C. Overall, the results showed a significant potential use of flocculants with increasing temperature, by providing considerably higher permeated fluxes.

Supramolecular Interaction Modulation in Thermosensitive Composites: Enantiomeric Recognition and Chiral Site Regeneration

“…Consequently, the functional layer becomes hydrophilic, promoting the interaction of chiral molecules with Rm-β-CD and finally boosting the transport efficiency. However, the J ( J S ) and e.e.% are similar at a low temperature (40 °C) probably because the mass transfer rate decreases at low temperatures . A low temperature indicates a low enantioselectivity.…”

“…However, the J (J S ) and e.e.% are similar at a low temperature (40 °C) probably because the mass transfer rate decreases at low temperatures. 43 A low temperature indicates a low enantioselectivity. Thus, the TCM shows an optimal performance at 45 °C for concentration-difference and constantpressure modes.…”

Effects of microalgal concentration and pH with flocculant on microfiltration

“…It is a trademark of Tanac (Brazil) and a tannin-based product modified by a physicochemical process. It is obtained from Acacia mearnsii and is a high-power flocculant [6,14,15]. Microalgal species, such as Monoraphidium sp.…”

“…However, when microfiltration is combined with a flocculation-sedimentation process, they increase the harvest efficiency and reduce the operational and maintenance costs [21,22]. Several control strategies can be applied to prevent fouling, such as pH modification, microalgal concentration, flocculants, and the critical flux concept [14,15]. The critical flux concept has been proposed as a smooth and easy fouling control method that takes advantage of the transition of a filtration system between nonfouling and particle deposition states by tuning the system flux rate [23,24].…”