Investigation of reverse ionic diffusion in forward-osmosis-aided dewatering of microalgae: A molecular dynamics study

Jester N Itliong; Al Rey C Villagracia; Joaquin Lorenzo V Moreno; Kurt Irvin M Rojas; Gian Paolo O Bernardo; Melanie Y David; Robby B Manrique; Aristotle T Ubando; Alvin B Culaba; Allan Abraham B Padama; Hui Lin Ong; Jo-Shu Chang; Wei-Hsin Chen; Hideaki Kasai; Nelson B Arboleda Jr

doi:10.1016/j.biortech.2019.01.109

Investigation of reverse ionic diffusion in forward-osmosis-aided dewatering of microalgae: A molecular dynamics study

Bioresour Technol. 2019 May:279:181-188. doi: 10.1016/j.biortech.2019.01.109. Epub 2019 Jan 24.

Authors

Affiliations

¹ Physics Department, College of Science, De La Salle University, 2401 Taft Ave., Malate, 1004 Manila, Philippines; Applied Physics Department, Eulogio "Amang" Rodriguez Institute of Science and Technology, Nagtahan, Sampaloc, Manila, Philippines. Electronic address: jester_itliong@dlsu.edu.ph.
² Physics Department, College of Science, De La Salle University, 2401 Taft Ave., Malate, 1004 Manila, Philippines; Advanced Nanomaterials Investigation and Molecular Simulations (ANIMoS) Research Unit, CENSER, De La Salle University, 2401 Taft Ave., Malate, 1004 Manila, Philippines; Department of Agricultural and Biosystems Engineering, The University of Arizona, Tucson, AZ 85721, USA.
³ Physics Department, College of Science, De La Salle University, 2401 Taft Ave., Malate, 1004 Manila, Philippines; Advanced Nanomaterials Investigation and Molecular Simulations (ANIMoS) Research Unit, CENSER, De La Salle University, 2401 Taft Ave., Malate, 1004 Manila, Philippines.
⁴ Physics Department, College of Science, De La Salle University, 2401 Taft Ave., Malate, 1004 Manila, Philippines.
⁵ Mechanical Engineering Department, De La Salle University, 2401 Taft Ave., Malate, 1004 Manila, Philippines.
⁶ Institute of Mathematical Sciences and Physics, University of the Philippines, Los Baños, Laguna, Philippines.
⁷ School of Materials Engineering, Universiti Malaysia Perlis, Kompleks Pusat Pengajian Jejawi 2, 02600 Arau, Perlis, Malaysia; Centre of Excellence for Biomass Utilization, Universiti Malaysia Perlis, Lot 17, Kompleks Pusat Pengajian Jejawi 2, 02600 Jejawi, Arau, Malaysia; Taiwan-Malaysia Innovation Center for Clean Water and Sustainable Energy (WISE Center), Lot 17, Kompleks Pusat Pengajian Jejawi 2, 02600 Jejawi, Arau, Malaysia.
⁸ Research Center for Energy Technology and Strategy, National Cheng Kung University, Tainan 701, Taiwan; Department of Chemical Engineering, National Cheng Kung University, Tainan 701, Taiwan; College of Engineering, Tunghai University, Taichung 407, Taiwan.
⁹ Research Center for Energy Technology and Strategy, National Cheng Kung University, Tainan 701, Taiwan; Department of Aeronautics and Astronautics, National Cheng Kung University, Tainan 701, Taiwan.
¹⁰ National Institute of Technology, 679-3 Nishioka, Uozumi-cho, Akashi-City, Hyogo-Prefecture 674-8501, Japan.
¹¹ Physics Department, College of Science, De La Salle University, 2401 Taft Ave., Malate, 1004 Manila, Philippines; Advanced Nanomaterials Investigation and Molecular Simulations (ANIMoS) Research Unit, CENSER, De La Salle University, 2401 Taft Ave., Malate, 1004 Manila, Philippines; De La Salle University - Science and Technology Complex, Biñan, Laguna, Philippines.

PMID: 30731357
DOI: 10.1016/j.biortech.2019.01.109

Abstract

This study aimed to investigate the transport mechanisms of ions during forward-osmosis-driven (FO-driven) dewatering of microalgae using molecular dynamics (MD) simulations. The dynamical and structural properties of ions in FO systems of varying NaCl or MgCl₂ draw solution (DS) concentrations were calculated and correlated. Results indicate that FO systems with higher DS concentration caused ions to have lower hydration numbers and higher coordination numbers leading to lower diffusion coefficients. The higher hydration number of Mg²⁺ ions resulted in significantly lower ionic permeability as compared to Na⁺ ions at all concentrations (p = 0.002). The simulations also revealed that higher DS concentrations led to higher accumulation of ions in the membrane. This study provides insights on the proper selection of DS for FO systems.

Keywords: Forward osmosis; Microalgae dewatering; Molecular dynamics; Reverse ionic diffusion.

MeSH terms

Diffusion
Ions / chemistry
Microalgae*
Molecular Dynamics Simulation
Osmosis
Permeability
Sodium Chloride / chemistry
Water

Substances

Ions
Water
Sodium Chloride