*2.2.3 Industrial pollution*

Industrial wastewater is a generic term involving a wide array of wastewater discharged out of various industries [54]. Indeed, there are many kinds of industrial wastewater, with complex composition, because water fulfills several roles and functions in all types of industries. Measurements of parameters like biochemical oxygen demand (BOD), COD, pH, and alkalinity can allow to classify industrial pollution [55]. Indeed, industrial effluents can be classified according to the dominant nature of pollution, and it may be characterized by a high concentration of organic/inorganic compounds [56]. It should be noted that among the industries generating waste, certain of the most dangerous wastewater comes from sectors such as refineries, mining, tanneries, pharmaceuticals, pulp mills, and sugar production/distillery [57]. The food and agriculture industries generate wastewaters with high BOD, which is estimated to 0.6–20 m3 wastewater/ton of product (such as bread/butter/milk or fruit juice). For instance, the conventional process in distillery industry generates ~15 L of wastewater per liter of alcohol with a BOD level of about 90,000 mg/L [57]. The most important contributor of wastewater volume (18%), COD (23%), and a major source of NH4 + –N is the paper and paper products industry, while the raw chemical material and chemical products industry is the dominant source of NH4 + –N (35.3%) and an important source of COD and petroleum hydrocarbons [59]. Around 80% of the heavy metal discharges into water sources come from four industries, namely, the nonferrous metal manufacturing and processing industry (27.5%), the fur and leather products manufacturing industry (19.4%), the metal product manufacturing industry (17.7%), and the nonferrous metal ore mining industry (14.0%). This is also true for the Moroccan industrial activities and its discharges. According to the Moroccan federation of metallurgical, mechanical, and electromechanical industries, this industrial sector includes more than 1000 companies divided into four main sub-sectors, including iron and steel, metal transformation, coating, surface treatment, and services related to the metallurgical, mechanical, and electromechanical industries.

#### *2.2.3.1 General information on metal pollutants*

Although metals are natural components of the Earth's crust and contribute in various physiological processes of living organisms, their elevated concentrations (above the level of homeostatic regulation) produced by industrial activity [58] can be toxic to human and ecological receptors. The majority of elemental metals and their compounds and complexes are extremely stable in the environment [59]. Most metals are extremely soluble in circumneutral waters (as in **Figure 5**) [60].

Furthermore, metals are excellent conductors of electricity and mostly enter chemical reactions as positive ions. These metals are often involved in electron transfer reactions involving oxygen and leads to the formation of toxic oxyradicals [61]. The metals' fate and toxicity are highly dependent on their speciation or the form in which they exist in a given aquatic system [7]. An example of the importance

**49**

**Nanomaterial**

Nanoparticles

Iron (Fe0) (nanoscale zero valent iron (NZVI))

Coated with graphene oxide (GO)

5 mg/L 100 mg/L 100 mg/L

5 g/L 0.25 g

Room

1 h

78%

Room

30 min

>96.5%

6.9

1 g/L

—

8 h

90%

Iron (Fe0) (NZVI)

Iron (Fe0) (NZVI)

Iron (Fe0) (NZVI)

TiO2/Fe0

Nano-alumina

CNTs CNTs

Nanotubes Nanofibers

Nanoshell Nanocluster Nanocomposites

SiO2-FeOOH-Fe core shell

Spherical NZVI

Carbon-silicon

Iron/chitosan/zirconium

composite

Magnetic graphene

Nanosized lanthanum

20 mg/L

6–8

40 mg

293–

30 min

138.88 mg/g

313 K

hydrous

NZVI

—

—

—

64 mg/L 80 mg/L 50 mg/L 1–1000 mg/L

3

—

—

3–7

4 mg/L

100 mg

—

60 min

44.89%,11.34 mg/g

89.3 mg/g

—

60 min

95%

3

—

—

120 min

99.84%

Chitosan

—

Oxidized Iron oxide nanoparticle

immobilized

Microalgae

30 mg/L

6.5–

—

—

16 days

87 ± 4%

7.0

immobilized

Chitosan nanofibers

30 mg/L

6.5–

—

—

16 days

32 ± 3%

7.0

40 mg/g 50–600 mg/L 2.5–100 mg/L

7

50 mg

5 mg

25 °C

90 min

91.75%

25 °C

50 h

70%

4.4

1 g/L

25 ± 2 °C

70 min

4 mg/g

Pd-Cu deposited on

NZVI

Fresh NZVI coated

1 mg/ml

0.1 g/10 ml

20 °C

2 min

100%

with nickel

—

10 mg/L

3

1:10 ratio of

30 min

95%

TiO2/Fe0

**Type**

**Modification**

**Initial NO3ˉ concentration**

**pH**

**Nanomaterial dose**

**T°**

**Contact Time**

**NO3ˉ removal efficiency**

*Pollution of Water Sources from Agricultural and Industrial Effluents: Special Attention…*

*DOI: http://dx.doi.org/10.5772/intechopen.86921*


#### *Pollution of Water Sources from Agricultural and Industrial Effluents: Special Attention… DOI: http://dx.doi.org/10.5772/intechopen.86921*

*Water Chemistry*

*2.2.3 Industrial pollution*

for the elimination of NO3ˉ and demonstrated that hydrotalcite-type compounds/ layered double hydroxides and chemically modified adsorbents are found promising sorbents for enhanced removal of NO3ˉ from water. Tyagi et al. [53] made a summary of relevant published data with some of the latest important findings on the use of nanomaterials as NO3ˉ adsorbents. These nanoparticles can be metallic, semiconductor, or polymeric. **Table 3** reports some of the different nanomaterials used for NO3ˉ removal along with their experimental working parameters such as

Industrial wastewater is a generic term involving a wide array of wastewater discharged out of various industries [54]. Indeed, there are many kinds of industrial wastewater, with complex composition, because water fulfills several roles and functions in all types of industries. Measurements of parameters like biochemical oxygen demand (BOD), COD, pH, and alkalinity can allow to classify industrial pollution [55]. Indeed, industrial effluents can be classified according to the dominant nature of pollution, and it may be characterized by a high concentration of organic/inorganic compounds [56]. It should be noted that among the industries generating waste, certain of the most dangerous wastewater comes from sectors such as refineries, mining, tanneries, pharmaceuticals, pulp mills, and sugar production/distillery [57]. The food and agriculture industries generate wastewa-

(such as bread/butter/milk or fruit juice). For instance, the conventional process in distillery industry generates ~15 L of wastewater per liter of alcohol with a BOD level of about 90,000 mg/L [57]. The most important contributor of wastewater

products industry, while the raw chemical material and chemical products industry

Although metals are natural components of the Earth's crust and contribute in various physiological processes of living organisms, their elevated concentrations (above the level of homeostatic regulation) produced by industrial activity [58] can be toxic to human and ecological receptors. The majority of elemental metals and their compounds and complexes are extremely stable in the environment [59]. Most

metals are extremely soluble in circumneutral waters (as in **Figure 5**) [60].

Furthermore, metals are excellent conductors of electricity and mostly enter chemical reactions as positive ions. These metals are often involved in electron transfer reactions involving oxygen and leads to the formation of toxic oxyradicals [61]. The metals' fate and toxicity are highly dependent on their speciation or the form in which they exist in a given aquatic system [7]. An example of the importance

petroleum hydrocarbons [59]. Around 80% of the heavy metal discharges into water sources come from four industries, namely, the nonferrous metal manufacturing and processing industry (27.5%), the fur and leather products manufacturing industry (19.4%), the metal product manufacturing industry (17.7%), and the nonferrous metal ore mining industry (14.0%). This is also true for the Moroccan industrial activities and its discharges. According to the Moroccan federation of metallurgical, mechanical, and electromechanical industries, this industrial sector includes more than 1000 companies divided into four main sub-sectors, including iron and steel, metal transformation, coating, surface treatment, and services related to the metallurgical, mechanical, and electromechanical industries.

wastewater/ton of product

–N is the paper and paper

+

–N (35.3%) and an important source of COD and

pH, adsorbent dose, initial NO3ˉ concentration, and temperature.

ters with high BOD, which is estimated to 0.6–20 m3

volume (18%), COD (23%), and a major source of NH4

*2.2.3.1 General information on metal pollutants*

+

is the dominant source of NH4

**48**

