6.2.9 UV irradiation
The average irradiance was measured at 0.8 mW/cm² using iodide/iodate
chemical actinometry (Boltan et al.,2003). To speed up the reaction, all
test solutions were agitated for 30 minutes at 350 rpm. 1440 mJ/cm² was
the final UV dose. Standard procedures used in UV/chlorine advanced
oxidation processes were used to determine the dosage of chlorine and
length of UV irradiation. Wang et al.(2015) The majority of studies on
the behaviour of micropollutants in UV or UV-based processes have been
carried out in laboratory environments, usually with solutions prepared
with lab water. Wastewater or natural river water samples are rarely
used in research, resulting in limited data on the behaviour of
micropollutants in wastewater during UV treatment (Cicek et al., 2007).
By gathering samples at every stage of the treatment process, the
elimination of estrogen in a full-scale wastewater treatment plant
(WWTP) was investigated. Pathogens can be effectively inactivated by UV
therapy, although their efficacy may be impacted by water quality
parameters such as turbidity and the presence of organic matter (Linden
et al., 2011).
6.2.10 Nanofiltration
A membrane filtering method called nanofiltration uses cylindrical pores
the size of nanometers that are arranged perpendicularly through the
membrane. These membranes are smaller than those used in microfiltration
and have pore diameters ranging from 1 to 10 nanometers. Reverse osmosis
(RO) membranes are slightly larger than those in ultrafiltration. Drugs
can be eliminated using three different methods by nanofiltration (NF)
membranes: adsorption, Sieving and electrostatic repulsion (Dolara et
al., 2012). The nanofiltration (NF) capacity, a sophisticated membrane
filtration method used to eliminate a range of pollutants, including
organic compounds. It started to be used in wastewater treatment in 2003
due to the molecules, heavy metals and various ions it contains (Van der
Bruggen & Vandecasteele., 2003). With pore sizes that typically range
from 0.1 to 1 nanometre, NF membranes function at the molecular level,
effectively rejecting larger particles while allowing smaller ions and
water molecules to pass through (Yaroshchuk, 2000). Because of this, NF
is especially useful for getting rid of drugs, substances that cause
hormone disruption, and other new pollutants that are hard to remove
using traditional treatment techniques (Hilal et al., 2004). It has low
energy consumption and higher rejection of contaminants (Das et al.,
2018). Because NF may achieve more than 90% clearance efficiency, it is
a potential choice for pharmaceutical distribution (Bolong et al.,
2009).