*3.1.1 Physical-chemical quality*

In order to determine the degree of pollution caused by this unit, we were brought during this work to study the physical–chemical quality of rejection to be treated. We will translate the physicochemical parameters evolution during a period of study 20 days, study period from 7 to 9-08 to 3-10-08 in **Figure 1** below.

\*PH: It is an important physiological parameter which influences the development of numerous microorganisms [21] as well as speciation and the solubility of heavy metals. During followed laborers, the pH value of this discharge (**Figure 2b**)

**Figure 1.**

*Temporary follow-up of the physico-chemical parameters of the global rejection of surface treatment unity [(2a) CE, (2b) pH, (2c) DCO, (2d) OD, and (2e) MES].*

**111**

*Characterization and Treatment of Real Wastewater from an Electroplating Company by Raw…*

fluctuate generally between 5 and 7, it is the optimal pH for the treatment by the raw chitin [22], except some exceptional cases such the case samples of days 22, 26, 29, 30. This is due to oil changes that have occurred in these samples (**Table 1**).

Bath depassivation hydrochloric Bath anodic degreasing 3-10-08 Bath Accident at work, breaking of a pickling bath in full swing

\*CE: The electrical conductivity varies generally between 3 and 4 for all samples except that of the 3-10-98, which is very important. This value is effectively due to break of baths cleaning. The important values are recorded in the sampling days 22, 26 and 30. This drain of the baths shows that the degreasing depassivation waters of the baths are enormously salted. This salinity is essentially due to the high chloride concentration and to high acidity. The average

\*MES: The MES content confirms the statements made above. Levies where are oil changes occurring are charged by the MES. Indeed, the MES concentration is very high up to a maximum of 4.59 g/l and so exceed those generally encountered in domestic wastewater [23]. This result can be explained by the release of metal-

DCO: It present contents in variable organic matters from 96 to 3240 mg/l, but in general the value is situated near 200 mg/l, they are lower in standards dictated

OD: **Figure 2d** of OD brings to light an almost permanent state of anaerobiosis. The invalid contents of the oxygen in this discharge are due to the biological activity and to the absence of contributions in oxygen. A deficiency of this element in such

lic waste and the solid deposits which accumulate at the bottom of a bath.

Minimum values are recorded in these samples.

*Daily evolution of the heavy metals concentration in the discharge.*

22-9-08 Bath drain depassivation sulfuric 26-9-08 Bath chemical degreasing 29-9-08 Baths depassivation hydrochloric 30-9-08 Bath depassivation sulfuric

**Sampling Drain**

by the limits values of the indirect discharge [24].

value is of the order of 3.96 ms/cm.

*DOI: http://dx.doi.org/10.5772/intechopen.89058*

**Figure 2.**

**Table 1.**

*Dates and the bath affected by drain.*

*Characterization and Treatment of Real Wastewater from an Electroplating Company by Raw… DOI: http://dx.doi.org/10.5772/intechopen.89058*

#### **Figure 2.**

*Recent Advancements in the Metallurgical Engineering and Electrodeposition*

**3.1 Physical-chemical quality of wastewater to be treated**

**on raw chitin**

*3.1.1 Physical-chemical quality*

**3. Characterization and treatment of global rejection by adsorption** 

In order to determine the degree of pollution caused by this unit, we were brought during this work to study the physical–chemical quality of rejection to be treated. We will translate the physicochemical parameters evolution during a period

\*PH: It is an important physiological parameter which influences the development of numerous microorganisms [21] as well as speciation and the solubility of heavy metals. During followed laborers, the pH value of this discharge (**Figure 2b**)

*Temporary follow-up of the physico-chemical parameters of the global rejection of surface treatment unity* 

*[(2a) CE, (2b) pH, (2c) DCO, (2d) OD, and (2e) MES].*

of study 20 days, study period from 7 to 9-08 to 3-10-08 in **Figure 1** below.

**110**

**Figure 1.**

*Daily evolution of the heavy metals concentration in the discharge.*


#### **Table 1.**

*Dates and the bath affected by drain.*

fluctuate generally between 5 and 7, it is the optimal pH for the treatment by the raw chitin [22], except some exceptional cases such the case samples of days 22, 26, 29, 30. This is due to oil changes that have occurred in these samples (**Table 1**). Minimum values are recorded in these samples.

\*CE: The electrical conductivity varies generally between 3 and 4 for all samples except that of the 3-10-98, which is very important. This value is effectively due to break of baths cleaning. The important values are recorded in the sampling days 22, 26 and 30. This drain of the baths shows that the degreasing depassivation waters of the baths are enormously salted. This salinity is essentially due to the high chloride concentration and to high acidity. The average value is of the order of 3.96 ms/cm.

\*MES: The MES content confirms the statements made above. Levies where are oil changes occurring are charged by the MES. Indeed, the MES concentration is very high up to a maximum of 4.59 g/l and so exceed those generally encountered in domestic wastewater [23]. This result can be explained by the release of metallic waste and the solid deposits which accumulate at the bottom of a bath.

DCO: It present contents in variable organic matters from 96 to 3240 mg/l, but in general the value is situated near 200 mg/l, they are lower in standards dictated by the limits values of the indirect discharge [24].

OD: **Figure 2d** of OD brings to light an almost permanent state of anaerobiosis. The invalid contents of the oxygen in this discharge are due to the biological activity and to the absence of contributions in oxygen. A deficiency of this element in such

effluent can have serious implications for their treatment, fermentation, release of smell, etc. This characterization shows that the wastewater of the unit can be considered relatively stable if we eliminate the variations dictated by the draining. In other words the effluent can be easily handled if we avoid the draining or we get back them in the other pipe to treat them to part and thus insure a continuous treatment of the global discharge of the unit (**Table 1**).

### *3.1.2 Metallic pollution analysis*

The global discharge contains numerous metals that cannot be separated. We focused our study on three metals Cu, Cr and Ni. The results of the analysis of heavy metals in the effluent are illustrated by the **Figure 2**.

Cu: The levels of Cu2+ vary from 5.12 mg/l to 97.76 mg/l (**Figure 2**), the temporary fluctuations in this element are much more pronounced. The registered minimal value exceeds 5 times the PVL (1 mg /l). The contents of Cu2 + achieve in average 22.21 mg/l. This is due to currents after plating rinses.

Cr: The concentrations of chromium fluctuate between a minimal value of 0.11 mg/l and a maximal value of 63.86 mg/l (**Figure 2**). The most values exceed the PVL of Cr (2 mg/l).

Ni: as far as the nickel is concerned, the registered concentrations are enormously important and far from being in compliance with national standards. The maximal content is registered the takings of 28-9-08.

From these results, we can identify the following points:


It appears from these results that the effluent of this unit presents a big risk on the receiving environment; this is by accumulation along the food chain of the enormous quantities of rejected heavy metals [19]. During the study of the impact of the metallic pollution on the Casablanca coast, it showed that the dosage of metallic elements in the biological compartment crab *Eriphia spinifrons* of Fe, Cr, Pb, and Cd in bivalves *Mytilus* sp. *Mactra* and *Corallina* are rather high, which indicates a possible threat of the health because of the consumption of these mollusks (**Table 2**).

#### **3.2 Treatment test for global rejection**

The results for the Cu2+ are summarized in **Table 2**.

**Figure 3** indicates the changes of removal rates of heavy metals with the change of added quantity of raw chitin. For every mass, the raw chitin reduces the residual amount of Cu2+ in all treated samples even if the used quantity is weak, quoting the example of 250 mg.

**113**

**Table 3.**

what is in agreement with [16].

ered constant from 250 mg (**Table 3**).

*Average removal percentages evolution of Cu for both materials.*

*concentration as a function of added mass of Ccra.*

*Characterization and Treatment of Real Wastewater from an Electroplating Company by Raw…*

**Test 1 Co = 0.78 mg/l**

> **Ceq (mg/l)**

**Weights (mg)**

**Test 2 Co = 1.31 mg/l**

> **Ceq (mg/l)**

**Weights (mg)**

**Ccre Ccra**

**Ceq (mg/l)**

 0.45 30 1.05 50 0.17 50 0.57 0.32 60 1.00 100 0.16 100 0.42 0.30 90 0.82 150 0.13 150 0.89 0.28 120 0.76 200 0.12 200 0.27 0.25 150 0.67 250 0.07 250 0.19

**Test 2 Co = 1.31 mg/l**

180 0.15 180 0.57 300 0.05

*Evolution of the equilibrium concentration according to the dose of the material to remove.*

**Weights (mg)**

By calculating the average percentage removal of Cu for both materials (**Table 3**), we noticed that the highest percentages of elimination are marked for water treated by the Ccra. Whereas the percentages relative to Ccre are weaker than

*(a) Variation of the Cu concentration as a function of added mass of Ccre. (b) Variation of the Cu* 

For a given sample, when the mass of material increases, the percentage of reduction increases slightly. The variation of the percentage change can be consid-

Co mg/l 0.78 1.31 1.01 12.22 Ceq mg/l 0.25 0.67 0.13 0.39 % 67.95 48.85 87.13 96.80

**Ccre Ccra Test 1 Test 2 Test 1 Test 2**

*DOI: http://dx.doi.org/10.5772/intechopen.89058*

**Ceq (mg/l)**

**Test 1 Co = 0.78 mg/l**

**Weights (mg)**

**Table 2.**

**Figure 3.**

*Characterization and Treatment of Real Wastewater from an Electroplating Company by Raw… DOI: http://dx.doi.org/10.5772/intechopen.89058*


#### **Table 2.**

*Recent Advancements in the Metallurgical Engineering and Electrodeposition*

ment of the global discharge of the unit (**Table 1**).

heavy metals in the effluent are illustrated by the **Figure 2**.

average 22.21 mg/l. This is due to currents after plating rinses.

From these results, we can identify the following points:

maximal content is registered the takings of 28-9-08.

dead rinsing is often exceeded.

values are recorded in the case of Cr.

**3.2 Treatment test for global rejection**

*3.1.2 Metallic pollution analysis*

PVL of Cr (2 mg/l).

effluent can have serious implications for their treatment, fermentation, release of smell, etc. This characterization shows that the wastewater of the unit can be considered relatively stable if we eliminate the variations dictated by the draining. In other words the effluent can be easily handled if we avoid the draining or we get back them in the other pipe to treat them to part and thus insure a continuous treat-

The global discharge contains numerous metals that cannot be separated. We focused our study on three metals Cu, Cr and Ni. The results of the analysis of

Cu: The levels of Cu2+ vary from 5.12 mg/l to 97.76 mg/l (**Figure 2**), the temporary fluctuations in this element are much more pronounced. The registered minimal value exceeds 5 times the PVL (1 mg /l). The contents of Cu2 + achieve in

Cr: The concentrations of chromium fluctuate between a minimal value of 0.11 mg/l and a maximal value of 63.86 mg/l (**Figure 2**). The most values exceed the

Ni: as far as the nickel is concerned, the registered concentrations are enormously important and far from being in compliance with national standards. The

1.Among the three metals Cu, Ni and Cr no one presents normal means in comparison with the project national standards (PVL) and the international standards (FAO, EQO, etc.) This is due to the fact that, in general, the step of

are the most raised with regard to the other one baths of plating.

the health because of the consumption of these mollusks (**Table 2**).

The results for the Cu2+ are summarized in **Table 2**.

2.The average grade is the highest registered in the case of Ni (**Figure 2**). This is due on the one hand to the fact that the nicklage is in the most part of chains and on the other hand to the fact that the standards of the bath Ni (300 mg/l)

3.The temporary fluctuations in heavy metal contents are essentially explained by the following client commands. The bath can work hundreds of parts by hours, consequently current rinsing will strongly by loaded. The minimal

It appears from these results that the effluent of this unit presents a big risk on the receiving environment; this is by accumulation along the food chain of the enormous quantities of rejected heavy metals [19]. During the study of the impact of the metallic pollution on the Casablanca coast, it showed that the dosage of metallic elements in the biological compartment crab *Eriphia spinifrons* of Fe, Cr, Pb, and Cd in bivalves *Mytilus* sp. *Mactra* and *Corallina* are rather high, which indicates a possible threat of

**Figure 3** indicates the changes of removal rates of heavy metals with the change of added quantity of raw chitin. For every mass, the raw chitin reduces the residual amount of Cu2+ in all treated samples even if the used quantity is weak, quoting the

**112**

example of 250 mg.

*Evolution of the equilibrium concentration according to the dose of the material to remove.*

**Figure 3.**

*(a) Variation of the Cu concentration as a function of added mass of Ccre. (b) Variation of the Cu concentration as a function of added mass of Ccra.*

By calculating the average percentage removal of Cu for both materials (**Table 3**), we noticed that the highest percentages of elimination are marked for water treated by the Ccra. Whereas the percentages relative to Ccre are weaker than what is in agreement with [16].

For a given sample, when the mass of material increases, the percentage of reduction increases slightly. The variation of the percentage change can be considered constant from 250 mg (**Table 3**).


**Table 3.**

*Average removal percentages evolution of Cu for both materials.*

Ni: To estimate the efficiency of the material for the treatment this wastewater, we followed the evolution of the residual concentration of the Ni according to the various injected doses. The optimal dose of the material is chosen according to the quality wished by the water treaty. It is generally obtained when the ratio of M2+ equilibrium/M2+ original becomes little bit constant.

**Figure 4** shows that the residual amount of Ni after adsorption on the Ccre decreases gradually by increasing the dose of the material. For the Ccra the concentration in the equilibrium after treatment by 50 mg does not differ any more from that stayed after treatment by 150 or 200 mg. This results shows that the Ni shows an affinity important for Ccra. This is at the middle in evidence by the efficiencies on elimination which are maximums for Ccra.

Cr: The results of the dosage of the chromium before and after adsorption are included in **Table 4** below.

From this table, the removal efficiency increases as the Ccre metal concentration decreases. This agrees well with the isothermal studies [16], even if the physico-chemical quality of the water differs. We should note also that all the initial concentrations exceed the PVL fixed to 0.2 mg/l (**Table 5**). After treatment by the Ccra and by Ccre, the concentrations become lower than the standards. The hexavalent chromium is weakly eliminated by Ccre and

#### **Figure 4.**

*Changes in removal efficiencies of Ni as a function of dose % of the material removal.*


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*Characterization and Treatment of Real Wastewater from an Electroplating Company by Raw…*

Co (mg/l) 0,411 0,564 3,204 Ceq (mg/l) 0,024 0,100 0,044 PVL (mg/l) 0,2 0,2 0,2

*Evolution of the concentration equilibrium Ceq according to the initial concentration C0 for a dose of 0.6 mg/l.*

**Ccre Ccre Ccra**

by Ccra [14, 16], yet in this discharge, the elimination of chromium is very

**4. Characterization and treatment of current rinsing by adsorption** 

We have studied the characterization and the treatment of the rejects of the metallization baths of metals Cu, Zn, Cr and Ni. The physico-chemical rinses aware of four baths metallization (Cu, Zn, Cr and Ni) has been grouped by the following

pH: Because of degreasing, etching and galvanic deposition, we worked with solutions of different types of reactions. We have to avoid absolutely the training of the slightest traces of a solution in what is next. In addition, we must ensure that no residual solution in the emptiness or back of the room, because this residue would affect extremely, adversely the adhesion of a plating. According all to the possibilities the rinsing must be done in that is rinses current water which is characterized by a neutral pH, from **Table 6**, the recorded pH is more neutral. The pH of the rinsing current Cr is acidic. All rinses Cr acquire the characteristics of a flushing death. The same for the flushing power of Cu, since it works with an alkaline bath, the pH of the rinse is relatively high; it reached a maximum 8.33 for the collection of 11-9-08. In the case of current rinsing bath of Zn is acid so the pH values below 7. They reach 6.6 by the same observation was recorded in the case of power flushing Ni. Note that for the same type of rinsing, the pH does not change significantly

CE: Electrical conductivity is the lowest recorded in the case of the Cu current

MES: rinses have higher levels of MES ranging from 162 to 740 mg/l respectively for Ni and Zn. MES in the rinses is much smaller than the global rejection [14]. The

DCO: Highest values of DCO are recorded in the case of rinsing the zinc in the chain II, while for the rinsing of Ni, Cu and Cr, they do not exceed by 400 mg/l, that

rinsing, while the highest values are recorded for the zinc rinses (**Table 6**).

OD: it is large fluctuations, water bodies are generally well oxygenated (**Table 6**). Maximum values up to 17.8 mg/l are noted in the current Cu rinses. This contribution is due to the complete absence of a biological pollution in the rinse tanks. Besides all the settings in this collection are low, the DCO does not exceed 40 mg/l. For comparison the variation of average concentrations of these parameters depending on the type of metal rinsing are shown in **Figure 5** below.

rinses of zinc are the most loaded (**Figures 5** and **6**).

*DOI: http://dx.doi.org/10.5772/intechopen.89058*

important by both sources of the chitin.

**4.1 Physical-chemical characterization**

**on raw chitin**

*4.1.1 Physical-chemical*

from one chain to another.

value is less the limit values (PVL).

table:

**Table 5.**

#### **Table 4.**

*Evolution of the concentration of the Cr6+ according to the dose of the material.*

*Characterization and Treatment of Real Wastewater from an Electroplating Company by Raw… DOI: http://dx.doi.org/10.5772/intechopen.89058*


**Table 5.**

*Recent Advancements in the Metallurgical Engineering and Electrodeposition*

equilibrium/M2+ original becomes little bit constant.

on elimination which are maximums for Ccra.

included in **Table 4** below.

Ni: To estimate the efficiency of the material for the treatment this wastewater, we followed the evolution of the residual concentration of the Ni according to the various injected doses. The optimal dose of the material is chosen according to the quality wished by the water treaty. It is generally obtained when the ratio of M2+

**Figure 4** shows that the residual amount of Ni after adsorption on the Ccre decreases gradually by increasing the dose of the material. For the Ccra the concentration in the equilibrium after treatment by 50 mg does not differ any more from that stayed after treatment by 150 or 200 mg. This results shows that the Ni shows an affinity important for Ccra. This is at the middle in evidence by the efficiencies

Cr: The results of the dosage of the chromium before and after adsorption are

From this table, the removal efficiency increases as the Ccre metal concentration decreases. This agrees well with the isothermal studies [16], even if the physico-chemical quality of the water differs. We should note also that all the initial concentrations exceed the PVL fixed to 0.2 mg/l (**Table 5**). After treatment by the Ccra and by Ccre, the concentrations become lower than the standards. The hexavalent chromium is weakly eliminated by Ccre and

*Changes in removal efficiencies of Ni as a function of dose % of the material removal.*

**Ccra Ccre**

*Evolution of the concentration of the Cr6+ according to the dose of the material.*

**Test 1 Co = 0.41 mg/l**

**Weights (mg) Ceq** 

 0.044 60 0.024 60 0.100 0.016 90 0.002 90 0.060 0.011 120 0.018 120 0.087 0.053 150 0.014 150 0.056 0.020 180 0.019 180 0.033

**(mg/l)**

0.036 30 0.096 30 0.051

**Test 2 Co = 0.56 mg/l**

**Weights (mg) Ceq (mg/l)**

**114**

**Table 4.**

**Figure 4.**

**Test 1**

**Co = 3.204 mg/l**

**Weights (mg) Ceq** 

**(mg/l)**

*Evolution of the concentration equilibrium Ceq according to the initial concentration C0 for a dose of 0.6 mg/l.*

by Ccra [14, 16], yet in this discharge, the elimination of chromium is very important by both sources of the chitin.
