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Bioremediation for Sustainable Environmental Cleanup
Table 14.2. Wastewater generation standard for Paper and Pulp industry (CPCB 2000).
Industry
pH
SS
mg L–1
BOD3
mg L–1
COD mg
L–1
Particulate Matter
mg Nm–3
H2S
mg Nm–3
Large Pulp and Paper Industry
(Capacity 24000 Ton/annum)
6.5 – 8.5
100
30
350
250
10
Small Paper
and Pulp
Industry
Inland Surface
Water
5.5 – 9.0
100
30
-
-
-
Land
5.5 – 9.0
100
100
industries has different standards as per different pollution control authorities worldwide. As per the
Central Pollution Control Board of India, the standards for different textile wastewater effluents are
described in Table 14.4.
Textile wastewater contains pollutants like inorganic, organic and polymeric products (Brown
and Laboureur 1983). The pollutants include dyes, coloring agents, etc. The dye and coloring agents
are not only harmful to the biological ecosystems, they also block sunlight by covering the surface
layer of soil and water bodies (Choi et al. 2004). Table 14.5 summarizes the pollutants present and
their concentrations in the textile water from different studies conducted worldwide. Wastewaters
from textile industries have shown different levels of various inorganic pollutants, i.e., NH3, PO4
3–
and N, along with high DO, BOD, COD, TSS, TDS, EC, etc. According to a study by Adelodun
et al. (2021) and Lin and Peng (1994) large amounts of oil and grease are also present in the textile
wastewater.
Along with organic pollutants, textile wastewater is a contributor to heavy metals like Al, Cd,
Cu, Ni, Zn, Pb, Fe, Cr and Hg, etc. A study by Türksoy et al. (2021) has observed a high amount of
Cu (643.74), Zn (398.28) and Ni (95.56). Another study by Sungur and Gülmez (2015) showed the
highest amount of Al and Fe (103.13 mgL–1 and 80.13 mg kg–1) during the wet digestion of cotton
in the textile industry. These authors also found high amounts of Cd, Pb and Cr of 19.43, 189.4 and
382.3 mg kg–1, respectively, in textile sludge. The different concentrations of heavy metals in textile
wastewater observed by different studies are described in Table 14.6.
14.5.3 Dairy Industry
The dairy industry generates wastewater during the packaging of the produced milk. The water
also includes cleaning agents like detergents necessary for cleanliness. Overflow, leakages and
improper management also contribute to more wastewater. Waste produced from the dairy industry
is broadly classified into two types, i.e., effluent or wastewater and solid waste (Adesra et al. 2021).
Approximately 1–3 liter of wastewater is produced during the processing of 1 liter of milk, which
contains high organic pollutants, i.e., carbohydrates, protein and fat (Kushawha et al. 2011), BOD,
COD, TDS, TSS (Bazrafshan et al. 2013). Characteristics and quantity of the wastewater vary
based on the design of the plant, type of product processed, type of treatment, water consumption
(Lawrence et al. 2005) and season (Verma and Singh 2017). Before the discharge of the wastewater
from the dairy industry, the standards as per government rules of different countries should be
maintained. Different organic pollutants produced by the dairy industry are described in Table 14.7.
In 2020, global dairy exports reached to 78 million tons (in milk equivalents), an upsurge of
1.5% from 2019. Between 2016 and 2019, the dairy price index increased from USD 83 to 103 per
ton worldwide, and annual worldwide milk production in 2020 reached 860 million tons, a rise of
1.4% from 2019, mainly due to increased pro-duction in Asia, Europe and North America (FAO
2020). The standards set by environment (protection) rules of India, EPA and the World Bank group
for the maximum permissible limits of different pollutants from dairy wastewater are described in
Table 14.8.