Optimization of cellulose acetate nanofiltration membranes for micropollutant removal via genetic algorithms and high throughput experimentation

Abstract

Nanofiltration (NF) and reverse osmosis (RO) membranes have a high potential to remove low molecular weight trace contaminants in water that cannot be removed efficiently by conventional biological or physico-chemical treatments. However, membrane performance depends on several parameters involved in membrane synthesis. Multi-parameter optimization strategies, such as genetic algorithms (GAs) are extremely promising to minimize time and material consumption to direct membrane synthesis towards better separation properties (selectivity) of the targeted compounds combined with useful fluxes.Cellulose acetate membranes were prepared via phase inversion. The optimized parameters included compositional (polymer concentration, solvent) and also, for first time when using GA as optimization strategy in membrane synthesis, non-compositional on the level of the 2 membrane synthesis process and post treatment (temperature, annealing time), which have a great impact on membrane performance.Dead-end filtrations were carried out to evaluate membrane performance to retain ibuprofen in water by using High-Throughput experimentation (HT), which enables parallel testing and rapid acquisition of data sets and minimize time and material consumption. Ibuprofen was selected as it is one of the smallest molecules from relevant micropollutants present in drinking water. As result, membranes with ibuprofen retention up to 96% and permeabilities in the normal range of cellulose acetate (CA)-based reverse osmosis membranes were obtained, which also showed promising NaCl retention and twice the permeability compared to membranes prepared via a classical optimization parameter-by-parameter.

Selective isolation of bacteria for metagenomic analysis: Impact of membrane characteristics on bacterial filterability

“…NF membranes have a moderate retention for univalent salts. NF is mainly applied in drinking water purification process steps, such as water softening, decoloring and micro pollutant removal . In other industrial processes it is applied for the removal of specific components, such as coloring agents, the removal of pesticides from groundwater, removal of heavy metals from wastewater, wastewater recycling in laundries and nitrates removal …”

“…NF is mainly applied in drinking water purification process steps, such as water softening, decoloring and micro pollutant removal. 57,58 In other industrial processes it is applied for the removal of specific components, such as coloring agents, the removal of pesticides from groundwater, removal of heavy metals from wastewater, wastewater recycling in laundries and nitrates removal. [59][60][61] Microfiltration and ultrafiltration MF and UF are the most common classes associated with membrane filtration.…”

Use of Ionic Liquids and Co-Solvents for Synthesis of Thin-Film Composite Membranes

“…Membrane filtrations were performed in a high throughput (HT) membrane filtration device which allows simultaneous filtration of 16 membrane coupons with each an active area of 1.77 × 10 −4 m 2 [ 33 , 34 , 35 ]. The pressure driven filtrations in dead-end mode were performed at room temperature (RT) and 20 bar while stirring the feed at 360 rpm to minimize the effect of concentration polarization.…”

Genetic algorithms in chemometrics

“…Recently, several papers described applications of GAs in optimization such as Madaeni et al , Cano‐Odena et al , Shi and Xue , and Vadood et al . Bhatti et al in 2011 described response surface methodology and artificial neural network (ANN) approach for electrocoagulation of copper from simulated wastewater.…”