Abstract:
Today, the trend is towards the use of low-cost materials to develop green processes in the aim to
reduce cost and impact on environment. The use of low-cost materials of natural origin has been
proven to be very promising for the fabrication of ceramic membranes for wastewater treatment. In
this article, fabrication and testing of high performance microporous carbon membrane for nanofiltration
(NF) separation based on mineral coal and phenolic resin are reported. The preparation
of the NF composite membrane involved carbonizing a polymeric precursor deposited on a porous
supported membrane, using the vacuum slip-casting process to obtain a homogeneous NF top layer
almost without defects by one-step coating-carbonization cycle. To ensure a better final membrane
texture, several parameters including the viscosity of the casting suspension, the casting time and
the carbonization temperature were considered. A crack-free NF membrane with a thickness layer
of 1.36 μm, a mean pore size of 1.1 nm, and a molecular weight cut-off of 400 Da was obtained
using 1 min casting time and 45% of phenolic resin. These membranes were tested in the treatment
of textile wastewater. Promising results in terms of permeate flux and pollutant retention (COD
(72%), salinity (45%)) were obtained. The results further showed that the treated wastewater could
be recycled into the textile industry or can be discharged into the municipal sewerage in compliance
with legislations. In addition, a carbonization temperature of 650°C yielded best membranes
in terms of average pores size and membrane permeability with minimum energy consumption.
