**7. Conclusions**

The increasing pressure that the exacerbated demand on primary goods and commodities is placing to our environment by the development of larger communities will lead us to catastrophic and irreversible damages if a change of actions is not taken. Toxic and dangerous pollutants that are discharged in increasing quantities mean negative impacts to our natural resources, among which water is one of the most vulnerable as it is an absolutely necessary requisite for any form of life on

**179**

scientists.

*Low Dimensional Nanostructures: Measurement and Remediation Technologies Applied to Trace…*

Earth. Palliative solutions have been proposed in different scenarios with variable degrees of success. In this sense, we have presented a summary of some of the alternatives that have been explored to help in the remediation of water reservoirs, based on the application of a variety of nanomaterials coupled with traditional analytical techniques, and on the other hand supported with some innovations in terms of the

One of the multiple promising applications of nanotechnology is remediation. The current work mentioned some examples of applied nanotechnology such as testing before and after a remediation strategy is applied. The presented low dimensional (0D, 1D, 2D, and 3D) nanomaterials were coupled with traditional analytical techniques, and on the other hand, supported with some innovations in terms of the design, reuse, or efficiency. Most of the examples showed that concentration values lower than trace levels can be reached, which is an important fact concerning

The combination of nanotechnology and remediation opens an avenue of multiple options for environmental improvement strategies. It is an efficient alternative for the sensing, quantification, and removal of contaminants from water, specifically the cleaning of heavy metals, ideally to quantities lower than trace levels, as was exemplified in this chapter. The main advantages of the nanomaterials used for this purpose reside in their high sensitivity and selectivity that can be achieved at a reduced cost and with a lower time-consumption than other non-processed materials (for example volcanic rock shown in **Table 2**). Also, the nanoscale size means an impressive increment of the surface area of nanomaterials that can be translated into a higher reactivity. The reactivity allows the tuning of selectivity or combined selectivity; it means that any molecule with a specific affinity to any metal can be anchored to the nanostructure surface. Besides, nanostructured materials could be adapted for subsequent remediations and magnetic removal, reducing secondary

The combination of living systems, nanotechnology, and remediations extends the possibilities. Some microorganisms (dead or dead) are natural accumulators at trace levels and combined with nanostructures make a synergistic effect with improved sorption capacity; such combination allows the production of sustainable materials. Toxicity also concerns with this field, due to one of the main concerns about the extensive use of nanomaterials resides on the fact that the details on the nanostructure interaction with the environment and with different living organisms are still unknown. It means that systematic and extensive studies are required to aid to fill the current voids of data or information. Then, the toxicity is still a limitation on the use of nanomaterials in real samples. Other limitations such as the industrial manufacture tackle multiple difficulties due to do not readily exist regulation neither guidance on information requirements nor safety assessment. Apart from regulation, the right on intellectual property delays

It is true that one of the main concerns about the extensive use of nanomaterials resides on the fact that the details on the nanostructure interaction with the environment and with different living organisms are still unknown. It means that systematic and extensive studies are required to aid to fill the current voids of data or information. Another important issue is the recuperation of the nanomaterials once used. In some cases, the magnetic removal represents a practical option for recovery and reuse, but additional innovative strategies are needed. Overall, the application of nanomaterials to the removal of heavy metals from water is still a vast research opportunity area to be covered by current and future generations of

*DOI: http://dx.doi.org/10.5772/intechopen.93263*

design, reuse or efficiency.

highly toxic metals.

contamination.

the industrial application.

### *Low Dimensional Nanostructures: Measurement and Remediation Technologies Applied to Trace… DOI: http://dx.doi.org/10.5772/intechopen.93263*

Earth. Palliative solutions have been proposed in different scenarios with variable degrees of success. In this sense, we have presented a summary of some of the alternatives that have been explored to help in the remediation of water reservoirs, based on the application of a variety of nanomaterials coupled with traditional analytical techniques, and on the other hand supported with some innovations in terms of the design, reuse or efficiency.

One of the multiple promising applications of nanotechnology is remediation. The current work mentioned some examples of applied nanotechnology such as testing before and after a remediation strategy is applied. The presented low dimensional (0D, 1D, 2D, and 3D) nanomaterials were coupled with traditional analytical techniques, and on the other hand, supported with some innovations in terms of the design, reuse, or efficiency. Most of the examples showed that concentration values lower than trace levels can be reached, which is an important fact concerning highly toxic metals.

The combination of nanotechnology and remediation opens an avenue of multiple options for environmental improvement strategies. It is an efficient alternative for the sensing, quantification, and removal of contaminants from water, specifically the cleaning of heavy metals, ideally to quantities lower than trace levels, as was exemplified in this chapter. The main advantages of the nanomaterials used for this purpose reside in their high sensitivity and selectivity that can be achieved at a reduced cost and with a lower time-consumption than other non-processed materials (for example volcanic rock shown in **Table 2**). Also, the nanoscale size means an impressive increment of the surface area of nanomaterials that can be translated into a higher reactivity. The reactivity allows the tuning of selectivity or combined selectivity; it means that any molecule with a specific affinity to any metal can be anchored to the nanostructure surface. Besides, nanostructured materials could be adapted for subsequent remediations and magnetic removal, reducing secondary contamination.

The combination of living systems, nanotechnology, and remediations extends the possibilities. Some microorganisms (dead or dead) are natural accumulators at trace levels and combined with nanostructures make a synergistic effect with improved sorption capacity; such combination allows the production of sustainable materials. Toxicity also concerns with this field, due to one of the main concerns about the extensive use of nanomaterials resides on the fact that the details on the nanostructure interaction with the environment and with different living organisms are still unknown. It means that systematic and extensive studies are required to aid to fill the current voids of data or information. Then, the toxicity is still a limitation on the use of nanomaterials in real samples. Other limitations such as the industrial manufacture tackle multiple difficulties due to do not readily exist regulation neither guidance on information requirements nor safety assessment. Apart from regulation, the right on intellectual property delays the industrial application.

It is true that one of the main concerns about the extensive use of nanomaterials resides on the fact that the details on the nanostructure interaction with the environment and with different living organisms are still unknown. It means that systematic and extensive studies are required to aid to fill the current voids of data or information. Another important issue is the recuperation of the nanomaterials once used. In some cases, the magnetic removal represents a practical option for recovery and reuse, but additional innovative strategies are needed. Overall, the application of nanomaterials to the removal of heavy metals from water is still a vast research opportunity area to be covered by current and future generations of scientists.

*Trace Metals in the Environment - New Approaches and Recent Advances*

target contaminant and the type of sample to be treated.

**6. Perspectives**

unintended consequences.

learning programs [96, 97].

releasing them into the environment.

as follows:

areas.

**7. Conclusions**

that is just emerging.

and oxide-reduction processes whose adequate election depends basically of the

There is still a need to develop smarter nanomaterials for remediation purposes on different environments, particularly at trace levels. Significant facts can be listed

• Laboratory experiences on the removal of heavy metals based on the use of nanomaterials must be extended toward real environments potentializing their advantages, but also having in mind their potential risks to human health and to the ecosystems, areas which are poorly understood and might lead to

• The mobility, bioavailability, toxicity, and persistence of a wide variety of manufactured nanoparticles that are already in use, need to be studied [95]. This will provide qualitative and quantitative information for a better understanding of their potential risks, beyond their use in the heavy metal removal. For this issue, full-scale ecosystem-wide studies can be carried out by machine

• More studies focused on profitable strategies applied to the recovery and reuse of nanostructures need to be achieved. They will also allow the proposal of safe handling and disposal guidelines for the already used nanoparticles not only in environmental remediation protocols but in any other area that is already

• Accessible and low-cost pollution sensors based on an electrochemical or an optical response that can be easily implemented in an electronic device such as a smartphone, are urgently needed. These technologies are much less expensive that the traditional spectroscopic techniques and can transform every device into a mobile sensor, with probably thousands displayed in huge territorial

• Strategies for the maintenance or the improvement of water quality become mandatory in times when water access is becoming more and more difficult. In this context, the presence of different nanomaterials as an efficient, low-cost, and environmentally friendly alternative for the removal of heavy metals from waters to keep healthily environments [98] is a research and educational area

The increasing pressure that the exacerbated demand on primary goods and commodities is placing to our environment by the development of larger communities will lead us to catastrophic and irreversible damages if a change of actions is not taken. Toxic and dangerous pollutants that are discharged in increasing quantities mean negative impacts to our natural resources, among which water is one of the most vulnerable as it is an absolutely necessary requisite for any form of life on

**178**
