in a few refinery wastewater treatment plants. The steps involved in a sequencing
batch reactor process are
A. Fill:
It is a simple filling operation where wastewater from equalization tank is charged
into the reactor.
B. React:
Here, wastewater is aerated and biological activity starts sequentially.
C. Settle:
Mixed liquor suspended solids settle down after aeration is stopped. No flow is
allowed to enter or leave the reactor during settling.
D. Decant:
In this step, the lighter effluent is taken out from the top of the reactor. The settled
sludge is periodically retracted from the bottom of the reactor (International Petroleum Industry Environmental Conservation Association 2010; Shahryar 2017;
Alireza 2014).
Membrane Technology
Membrane technology is a separation technology (based on particle size) where a
selective barrier between two adjacent phases is applied for the separation of
submicron suspended and dissolved contaminants such as organic matter, nutrients,
turbidity, microorganisms, inorganic metal ions, etc., from wastewater in a modern
refinery. The separation efficiency depends on selectivity of membrane. The advantages of membrane technology are their transport selectivity as compared to other
processes, no need of any catalyst, additives and provides a clean compact technology. The membrane may be degraded after long-term utilization and fouled due to
clogging of pores and gel formation on its surface. So, the membrane efficiency and
flux decrease. The fouling can be controlled by using fouling or scaling inhibitors.
There are four types of pressure-driven membrane separation processes such as
microfiltration, ultrafiltration, reverse osmosis and nanofiltration. It is noticed that an
individual membrane technology is not suitable for oily wastewater treatment. A
combination of two or three types like ultrafiltration and reverse osmosis,
microfiltration and reverse osmosis, microfiltration and nanofiltration,
microfiltration and ultrafiltration, etc., is required (International Petroleum Industry
Environmental Conservation Association 2010; Central Pollution Control Board,
India 2018; Shahryar 2017).
A. Microfiltration:
Microfiltration is used for the rejection of suspended solids and emulsified oil
which have particle size greater than 0.1 μm approximately in refinery. After
8 Treatment of Petroleum Hydrocarbon Pollutants in Water
263
batch reactor process are
A. Fill:
It is a simple filling operation where wastewater from equalization tank is charged
into the reactor.
B. React:
Here, wastewater is aerated and biological activity starts sequentially.
C. Settle:
Mixed liquor suspended solids settle down after aeration is stopped. No flow is
allowed to enter or leave the reactor during settling.
D. Decant:
In this step, the lighter effluent is taken out from the top of the reactor. The settled
sludge is periodically retracted from the bottom of the reactor (International Petroleum Industry Environmental Conservation Association 2010; Shahryar 2017;
Alireza 2014).
Membrane Technology
Membrane technology is a separation technology (based on particle size) where a
selective barrier between two adjacent phases is applied for the separation of
submicron suspended and dissolved contaminants such as organic matter, nutrients,
turbidity, microorganisms, inorganic metal ions, etc., from wastewater in a modern
refinery. The separation efficiency depends on selectivity of membrane. The advantages of membrane technology are their transport selectivity as compared to other
processes, no need of any catalyst, additives and provides a clean compact technology. The membrane may be degraded after long-term utilization and fouled due to
clogging of pores and gel formation on its surface. So, the membrane efficiency and
flux decrease. The fouling can be controlled by using fouling or scaling inhibitors.
There are four types of pressure-driven membrane separation processes such as
microfiltration, ultrafiltration, reverse osmosis and nanofiltration. It is noticed that an
individual membrane technology is not suitable for oily wastewater treatment. A
combination of two or three types like ultrafiltration and reverse osmosis,
microfiltration and reverse osmosis, microfiltration and nanofiltration,
microfiltration and ultrafiltration, etc., is required (International Petroleum Industry
Environmental Conservation Association 2010; Central Pollution Control Board,
India 2018; Shahryar 2017).
A. Microfiltration:
Microfiltration is used for the rejection of suspended solids and emulsified oil
which have particle size greater than 0.1 μm approximately in refinery. After
8 Treatment of Petroleum Hydrocarbon Pollutants in Water
263