6.5.2 Biological Approaches
Physicochemical approaches have certain drawbacks like higher cost, high energy
input, changes in water quality, and disturbance in native flora communities. Therefore, recently biological or green approaches come into practices that are costeffective, require less energy, more reliable, feasible, and eco-friendly. In this,
different microorganisms such as bacteria, fungus, algae, etc., are used to degrade
wastewater contaminants. Microorganisms are used in different engineering set up
such as trickling filter, activated sludge process, membrane bioreactors, rotating
biological contactors, etc., for wastewater treatment. Several sustainable and green
approaches used for wastewater treatment are given in Table 6.1 and discussed as
below.
6.5.2.1 Bacterial Biodegradation
In wastewater treatment technology, the use of bacterial community in different
engineered systems such as trickling filter, rotating biological contactor, activated
sludge process, etc., or as a biosorbent is highly considerable. The metabolic rate of
bacteria determines its effectiveness in wastewater treatment. Microbial communities rich in species degrade a wider range of substrates than its pure culture.
Biosynthesis of extra cellular polymeric substances by microbial aggregates through
generated by cell lysis, secretion, released materials from cell surfaces are necessary
for maintaining biomass structure and protects bacterial cells against various contaminants. Biological wastewater treatment system has been designed by considering three aspects, such as engineering, ecological, and microbial. With design and
operation of wastewater treatment plants, integration of theoretical ecology allow
better prediction of microbial population, variations in communities structure and
function with changes in environmental conditions (Cydzik-Kwiatkowska and
Zielińska 2016). Investigation of microbial communities is important for degradation of wastewater released from pharmaceutical, petroleum refineries, textiles,
paper pulp industries, etc. (Ma et al. 2015).
Ajaz et al. (2019) reported that Alcaligenes aquatilis was used to decolorize 82%
synazol red 6HBN from wastewater at pH 7 after incubation of 4 days at 37
C.
Under static conditions, maximum decolorization of wastewater by A. aquatilis was
achieved in the presence of sawdust and yeast extract as a source of carbon and
nitrogen, respectively. Results further showed that the maximum wastewater decolorization, i.e., approximately 86% of multiple dyes was found in 5 days incubation.
A. aquatilis not only potentially decolorize wastewater but also transformed azo dyes
into different useful end products applied in the environmental biotechnology.
6 Wastewater Reuse in Peri-Urban Agriculture Ecosystem: Current Scenario,. . .
135
Physicochemical approaches have certain drawbacks like higher cost, high energy
input, changes in water quality, and disturbance in native flora communities. Therefore, recently biological or green approaches come into practices that are costeffective, require less energy, more reliable, feasible, and eco-friendly. In this,
different microorganisms such as bacteria, fungus, algae, etc., are used to degrade
wastewater contaminants. Microorganisms are used in different engineering set up
such as trickling filter, activated sludge process, membrane bioreactors, rotating
biological contactors, etc., for wastewater treatment. Several sustainable and green
approaches used for wastewater treatment are given in Table 6.1 and discussed as
below.
6.5.2.1 Bacterial Biodegradation
In wastewater treatment technology, the use of bacterial community in different
engineered systems such as trickling filter, rotating biological contactor, activated
sludge process, etc., or as a biosorbent is highly considerable. The metabolic rate of
bacteria determines its effectiveness in wastewater treatment. Microbial communities rich in species degrade a wider range of substrates than its pure culture.
Biosynthesis of extra cellular polymeric substances by microbial aggregates through
generated by cell lysis, secretion, released materials from cell surfaces are necessary
for maintaining biomass structure and protects bacterial cells against various contaminants. Biological wastewater treatment system has been designed by considering three aspects, such as engineering, ecological, and microbial. With design and
operation of wastewater treatment plants, integration of theoretical ecology allow
better prediction of microbial population, variations in communities structure and
function with changes in environmental conditions (Cydzik-Kwiatkowska and
Zielińska 2016). Investigation of microbial communities is important for degradation of wastewater released from pharmaceutical, petroleum refineries, textiles,
paper pulp industries, etc. (Ma et al. 2015).
Ajaz et al. (2019) reported that Alcaligenes aquatilis was used to decolorize 82%
synazol red 6HBN from wastewater at pH 7 after incubation of 4 days at 37
C.
Under static conditions, maximum decolorization of wastewater by A. aquatilis was
achieved in the presence of sawdust and yeast extract as a source of carbon and
nitrogen, respectively. Results further showed that the maximum wastewater decolorization, i.e., approximately 86% of multiple dyes was found in 5 days incubation.
A. aquatilis not only potentially decolorize wastewater but also transformed azo dyes
into different useful end products applied in the environmental biotechnology.
6 Wastewater Reuse in Peri-Urban Agriculture Ecosystem: Current Scenario,. . .
135