**3. Electrochemical methods industrial application**

As we know that Electrochemical methods have a wide spread application so can be practiced for the treatment of community, industrial waters and wastewaters. The requirement for the practice of electrochemical methods is to eliminate large particles from water. The electrochemical methods can take out pollutants (organic and inorganic), ions and microorganisms acquire for clean water of distilled water quality. The electrochemical reduction intended for metals salvage and conversion of determined organic compounds to a reduced amount of toxic forms.

Recently, special attention has been given to the treatment of industrial wastewater by using advanced treatment technologies, among all methodologies, electrochemical methods appears to be one of the most promising methods for treatment organic pollutant-containing wastewater. The profits of electrochemical technology include durability, low cost, easy operation, energy efficiency, automation, fast response, high sensitivity and environmental compatibility [24–26].

Furthermore, from the above discussion it can be illustrated that rGO/MOx nanocomposites modified electrode may be helpful to practice on industrial scale

**Figure 3.**

*Chemical industry contaminating water and detection of heavy metal ions (a, b), stripping voltammetry approach of rGO/MOx modified electrodes for the individual analysis (c) HMIs sensed few time in a flow from a chemical industry.*

*Electrochemical Techniques for the Detection of Heavy Metals DOI: http://dx.doi.org/10.5772/intechopen.110411*

as well as in laboratory. Here in the last paragraph we have schemed to illustrate a chemical industry **Figure 3(a)** continuously contaminating the water (environmental and underground) along with HMIs. As has been reported by various researchers that nanocomposites modified electrode have the capacity to sense/absorb HMIs. If system of three or multiple electrode with modified nanocomposite is incorporated, then some amount of heavy metal ions can be sensed/detected **Figure 3(b)**. Therefore, we suggest that if from various concentration (1-10 μM) few amount of HMIs is sensed/ detected by rGO/MOx modified electrode **Figure 3(c)**, in this way by using multiple nanocomposites modified electrodes when practiced may sense/detect few amount of heavy metal ions **Figure 3(d)**.

Therefore, if a plant having multiple modified electrodes **Figure 3(e)** connected together then HMIs sensed few times may decrease the concentration of HMIs from the waste water of the chemical industry. We suggest that in this regard rGO/MOx nanocomposites will be a best choice for the sensing/detection of heavy metal ions (HMIs) coming out from chemical industries contaminating drinking water.

### **4. Brief summary**

In this unit, we have emphases on the reduced graphene Oxide/metallic oxide (rGO/MOx) nanocomposites for both individual and simultaneous detection of heavy metal ions (HMIs) in solution with the help of analysis on square wave voltammetry (SWV) or differential normal pulse voltammetry (DNPV). The nanocomposite may be synthesized by hydrothermal or chemical vapor deposition (CVD) method. The expandable graphite (EG) was reduced to graphene oxide GO during hydrothermal treatment and reduced graphene oxide during chemical vapor deposition (CVD) method to enhance the flow of electron on modified electrode. Furthermore, the MOx nanoparticles dispersed on graphene sheets will tend to accumulate the HMIs on the electrode surface. The Sensitivity (μA/μM) for individual as well as simultaneous analysis, limit of detection (LOD) and limit of quantitation (LOQ ) both on DNPV and SWV voltammetry analysis and can recorded and calculated (**Tables 1** and **2**). That why Electrochemical techniques have the advantages of low cost, easy operation, fast response, high sensitivity and specificity, which are suitable for ion sensing.

### **5. Conclusion**

In this Unit, we are trying to describe the electrochemical stand by combing the reduced graphene oxide/metallic oxides (rGO/MOx) nanocomposites for the analysis of heavy metal ions (HMIs) in solution by electrochemical methods. The detection simultaneous limit (3σ method) used for HMIs of the rGO/MOx nanocomposite modified electrode can be calculated for electrochemical methods on individual analysis as well as simultaneous analysis.

The enhanced electrochemical performance can be ascribed to three factors (1) rGO could be used to prevent the aggregation of MOx nanocomposites, resulting in fast migration of electrons; the MOx nanocomposite with active planes recollect chemical sensitivity and adsorb heavy metal ions.
