26.6 Biotechnological Approaches for the Removal of ECs

401

solid particle and heavy metals can be removed. Other chemicals and hazardous

materials cannot be treated in this method.

26.5.2

Chemical Methods

After the physical treatment, waste will be treated with chemical means to remove

the undesirable contaminants. The use of chemicals for the treatment of waste may

also create byproducts that are hazardous to the environment and the living organ-

isms. Chemical digesters are used for the digestion of the solid waste to digest the

harmful chemicals from the waste.

26.5.3

Biotechnological Approach

Recent and efficient approach for the waste treatment is biotechnological one.

The biotechnological approaches include biodigestion, enzymatic treatment,

biofiltration, and bioremediation. These methods involve microorganisms and

algae for the degradation of the waste material and they play a very significant role

in the decomposition and removal of the hazardous materials. It is the novel and

advanced method for the biodegradation.

26.6

Biotechnological Approaches for the Removal

of ECs

26.6.1

Digestion by Membrane Bioreactor

Membrane bioreactors are used for the removal of contaminants from sludge.

They were used in the treatment of wastewater that contains micro-propellants

and pathogenic microbes. The substances like diltiazem, estrone, progesterone,

and acetaminophen were completely removed by this method. The activated

sludge treatment for the compounds such as bayrepel acid, diclofenac, and

diethyltoluamide (DEET) showed the removal efficiency of 50–100% [2].

26.6.2

Enzymatic Treatment

Enzymatic treatment of the waste is done using two common types of enzymes,

laccases or peroxidases. These enzymes are very good biocatalysts in the conver-

sion of the toxic organic components into nontoxic or less toxic products. These

treatments are mostly considered as tertiary ones. Laccases catalyze the conversion

of the alcoholic compounds, such as bisphenol A, triclosan, and nonylphenol [2].

A study shows that laccase is more efficient in the removal of Orange 2 (72.8%)

and Acid Orange 6 (45.3%). Many studies have reported the effective and exten-

sive use of peroxidases in the oxidation of a vast variety of ECs, including azo dyes,

nonsteroidal anti-inflammatory drugs (NSAIDs), hormones, antibiotics, and pesti-

cides. Enzymatic treatment was efficient in decolorizing Bromophenol Blue (98%),

while heterocyclic dyes, Methylene Blue, and Toluidine Blue O were least decol-

orized (only 10%) (Table 26.1).