Nanotechnology for Water Environmental Application

In developing countries like Pakistan, industries do not allocate budget for control and treatment of pollution due to limited resources. Most of the pollutants emitted from these industries are usually reusable but their capture from waste is highly uneconomical. This goal can be attained by synthesizing the advanced materials such as silica hybrids, the class of silica hybrids consisting of inorganic silica linked with organic ligands to form network structure. Their high porosity, surface area, and crystallinity provide a way for removing large amount of pollutants with small quantity of silica hybrids. These applications include the use of powder hybrids as adsorbent for removal of different pollutants such as heavy metals, persistent organic pollutants, and toxic organic chemicals. These functionalized hybrids can be further fabricated into thin films. This new form will be further used for catalytic degradation of various pollutants. Besides all these applications, these hybrids will have the potential to be used as sensors for detecting various pollutants in industries.

Nanomaterial Surface Modifications for Enhancement of the Pollutant Adsorption From Wastewater

With the development of dyeing, textile, leather, paper, and other chemical industries, an increasing amount of dye wastewater containing refractory organic dyes is discharged. Undoubtedly, much high content dye wastewater will lead to serious environmental issues such as color pollution, light penetration interference, and virulence to aquatic organisms, even endanger human health. Therefore, it is an imminent problem and has become a global concern to degrade dye wastewater efficiently. So far, many techniques have been used to degrade dyeing wastewater, such as chemical degradation, biological degradation, photochemical degradation, coagulation, membrane filtration, and combined methods. These methods have certain impacts on the degradation of dye wastewater, but usually with slow degradation rate, complex and high operation costs, as well as easily causing secondary pollution. The adsorption process is a simple, effective, and low-cost way to remove dyes.

Properties of Nanomaterials and Environment

The chapter provides a timely review of the various properties of nonmaterial and their applications into environmental compartments. An extensive variety of poisonous chemicals is discharged into the environment because of globalization and industrialization. The dimensional, compositional, geometric, and structural properties are fundamental to convey usefulness of the nanomaterials. The controlled sizes and shapes of nanoparticles are anticipated to yield unique catalytic, electrochemical, and photochemical properties. The electrochemical properties of monolayer-functional metal nanoparticles are expected to be controlled by the particle sizes. Metal nanomaterials have interesting optical properties due to strong surface plasmon absorption and field enhancement effects; metal oxides lack visible absorption due to very large bandgap. Nanocomposites have complex optical properties. Nanomaterials present gigantic advantages on diverse applications, catalysis, imaging, biotechnological, and sensor applications due to their improved properties.

Toxicocinetic and Mechanisms of Action of Nanoparticles

Human exposure to nanoparticles has been dramatically increased in the past 25 years as a result of the rapidly developing field of nanotechnology. Many have recognized the importance of identifying potential effects on human health associated with the manufacture and use of these important technology. Many questions remain unanswered regarding the short- and long-term effect, systemic toxicity, and carcinogenicity. Engineered nanoparticles can be taken up by the human body via inhalation, ingestion, dermal uptake, and injection. They can reach the bloodstream and ultimately affect multiple body organs such as liver and spleen or even transcend the blood-brain barrier. Because of the huge diversity of materials used and the wide range in size of nanoparticles, these effects will vary a lot. Local and systemic adverse effects consist of primarily inflammatory reactions. Other observed effects include generation of reactive oxygen species and subsequent oxidative stress, disruption of proteins, DNA, mitochondria and membrane structures, as well as changes in cell signaling pathways.

Wastewater Treatment in Removal of Heavy Metals

Nanotechnology is the area of nano science that shows great potential to establish a new process for wastewater treatment. It has been applied on a nanometer scale level. Currently, limited water resources and real treatment of wastewater is a chief requirement for the growing economy. It is in great demand to introduce the progressive wastewater treatment technologies. Therefore, the modern innovative processes in nanomaterial sciences have been appealing the target of scientists. The chapter addresses the developments in nanotechnology with respect to wastewater treatment, especially the removal of heavy metals and to the environmental applications. It will discuss the application of different classes of nanomaterials for wastewater treatment in removal of heavy metals and its possible effects to the environment. Therefore, the scope is to offer an overview of how nanomaterials are causing concerns related to heavy metal removal for water and in the surrounding environment.

Recent Progresses in Membranes for Proton Exchange Membrane Fuel Cell (PEMFC) for Clean and Environmentally Friendly Applications

Fuel cell has become an emerging renewable energy device with potential to meet energy demand by portable and transport applications with zero-emission, easy operation, and compact design. The chapter provides an insight into design and development of membranes for PEMFCs and recent progresses made in membranes so far. Although majority of research has focused on fluorinated and non-fluorinated membranes, these polymeric membranes have showed deteriorated properties at elevated temperature (>80oC) and lower relative humidity (30%). Considering the major issues with polymeric membranes, the authors have reviewed inorganic-organic nanocomposite membranes showing improved physical and electrochemical properties at elevated temperature and lower relative humidity. Recently, metal-organic framework (MOF), a novel and unique material, has attracted tremendous attention due to their enhanced proton conductivity, easy functionality, and stability. MOFs have also exhibited excellent compatibility with different polymeric materials that are also discussed in this chapter.

Nanomembrane Applications in Environmental Engineering

This chapter delivers an outline of the strategies and techniques that are used and developed for the fabrication of membrane techniques/methods for application in environmental engineering. Human activities are the cause of increased hazardous gases in atmosphere mainly in soil and water. Nanotechnology deals the ability to control matter at the nano-scale level. Materials prepared are in nano level and thus they will possess some special properties to deal with specific functions. One of the major aspects of nanotechnology is nanomembrane fabrication which is mainly employed for water purification plants. The chapter is specifically offers a full understanding of the technologies and laws used to synthesize membranes. The chapter also provides an introduction to techniques to characterize nanomembranes.

Nanoparticles for Degradation of Organic Pollutants

Water pollution is becoming a serious threat to the environment. The access to safe drinking water, especially for the poor, is reaching an alarmingly low level, and the number of people suffering from kidney, stomach, and liver diseases, etc. is increasing every day. Among various pollutants, organic pollutants have major contribution in the contamination of water. These pollutants include toxic dyes, pharmaceutical compounds, industrial chemicals, and organic solvents, etc. Various routes are being employed for the removal/degradation of these pollutants. The use of nanoparticles (i.e., metal nanoparticles, nanocomposites, carbon nanotubes, and graphene oxide-based nanocomposite materials) possesses significant position as photocatalysts. This chapter has a focus on the environment remediation using these nanomaterials and contains the recent work in this field.

Application of Magnetic Nanomaterials for Water Treatment

The availability of clean drinking water becomes a critical issue for all the people of the world due to a rapid increase in population and industrialization. The water bodies get contaminated due to the discharge of wastewater, that will not only disturb the aquatic life but also badly affect human health. Therefore, different methods are adopted to treat the contaminated water to make it clean and safe for people. In last few years, the nanomaterials have gained much attention for water treatment because of their unique properties. Among all nanomaterials, magnetic nanomaterials are considered more efficient and attractive because of their easy separation and reusable property. In this chapter, a brief review related to synthesis and characterization of MNM was studied along with their application in removal of dyes, heavy metals, and microbes from wastewater through simple adsorption processes.

Nanotechnology for Air Remediation

The world around us is a gift of God. A thrust to know and reconnoiter the environment around us is innate. Man has drastically explored and utilized the resources hidden in nature, but unfortunately in this sprint of development, the natural environment is severely affected. It is the need of the hour to focus on methodologies for environmental remediation. Many technologies have been developed to reduce the pollution causing factors. Use of nanotechnology for the sake of saving environment is an emerging field. Nano-technology is based on nano-sized (smaller than 1 micron) materials. Nanosize particles have initiated the advancement in new and low cost techniques for environmental pollution control including air pollution.