Nanotechnology in Wastewater Management: A New Paradigm Towards Wastewater Treatment.
TL;DR: The techniques being developed for wastewater treatment using nanotechnology based on adsorption and biosorption, nanofiltration, photocatalysis, disinfection and sensing technology are reviewed and the fate of the nanomaterials in wastewater treatment is highlighted.
Abstract: Clean and safe water is a fundamental human need for multi-faceted development of society and a thriving economy. Brisk rises in populations, expanding industrialization, urbanization and extensive agriculture practices have resulted in the generation of wastewater which have not only made the water dirty or polluted, but also deadly. Millions of people die every year due to diseases communicated through consumption of water contaminated by deleterious pathogens. Although various methods for wastewater treatment have been explored in the last few decades but their use is restrained by many limitations including use of chemicals, formation of disinfection by-products (DBPs), time consumption and expensiveness. Nanotechnology, manipulation of matter at a molecular or an atomic level to craft new structures, devices and systems having superior electronic, optical, magnetic, conductive and mechanical properties, is emerging as a promising technology, which has demonstrated remarkable feats in various fields including wastewater treatment. Nanomaterials encompass a high surface to volume ratio, a high sensitivity and reactivity, a high adsorption capacity, and ease of functionalization which makes them suitable for application in wastewater treatment. In this article we have reviewed the techniques being developed for wastewater treatment using nanotechnology based on adsorption and biosorption, nanofiltration, photocatalysis, disinfection and sensing technology. Furthermore, this review also highlights the fate of the nanomaterials in wastewater treatment as well as risks associated with their use.
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TL;DR: In this article, the photocatalytic degradation of dyes follows three types of mechanisms: (1) dye sensitization through charge injection, (2) indirect dye degradation through oxidation/reduction, and (3) direct photolysis of dye.
Abstract: The disposal of dye-contaminated wastewater is a major concern around the world for which a variety of techniques are used for its treatment. The photocatalytic treatment of dye-contaminated wastewater is one of the treatment methods. Semiconductor-assisted photocatalytic treatment of dye-contaminated wastewater has gained pronounced attention recently. This review outlines the recent advancements in the photocatalytic treatment of dye-contaminated wastewater. The photocatalytic degradation of dyes follows three types of mechanisms: (1) dye sensitization through charge injection, (2) indirect dye degradation through oxidation/reduction, and (3) direct photolysis of dye. Several experimental parameters like initial concentration of dyes, pH, and catalyst dosage significantly affect the photocatalytic degradation of dyes. The photocatalytic materials can be categorized into three generations. The single-component (e.g., ZnO, TiO2) and multiple component semiconductor metal oxides (e.g., ZnO–TiO2, Bi2O3–ZnO) are categorized as first-generation and second-generation photocatalysts, respectively. The photocatalysts dispersed on an inert solid substrate (e.g., Ag–Al2O3, ZnO–C) are classified as third-generation photocatalysts. Finally, we reviewed the challenges that affect the photocatalytic degradation of dyes.
61 citations
TL;DR: In this paper, the authors provide insights into advanced and emerging state-of-the-art technologies for safe and efficient treatment of industrial oily wastewater, which is one of the most hazardous wastewaters, causing serious environmental and health threats to the ecosystems, flora and fauna.
Abstract: Oily wastewater consists of fats, oils and greases together with a broad spectrum of dissolved organic and/or inorganic substances in suspension. It is regarded as one of the most hazardous wastewaters, causing serious environmental and health threats to the ecosystems, flora and fauna. The global increase in the discharge of oily wastewater coupled with stringent regulations for effluent discharge and incessant drive for re-use of treated wastewater necessitate the need for treatment of the wastewater. Conventional approaches employed in the past are inept for oily wastewater treatment due to low treatment efficiency and high operational costs, among others, hence the need for adoption of advanced technologies as promising alternatives to existing treatment systems for oily wastewater. Furthermore, the use of combined treatment processes is effective for the removal of hazardous pollutants present in high-strength oily wastewater. This review provides insights into advanced and emerging state-of-the-art technologies for safe and efficient treatment of industrial oily wastewater.
60 citations
TL;DR: In this article , the authors compare synthetic and naturally occurring nanoparticles and nanostructured materials to determine their nanoscale characteristics and to identify particular knowledge gaps related to the environmental application of nanoparticles.
Abstract: Nanotechnology has infiltrated all sectors due to its unique and evident impacts, which give the scientific community numerous breakthroughs in the medical, agricultural, and other domains. Nanomaterials (NMs) have risen to prominence in technological breakthroughs due to their adjustable physical, chemical, and biological characteristics and superior performance over bulk equivalents. NMs are divided into many categories based on size, composition, capping agents, form, and origin. The capacity to forecast NMs' unique features raises the value of each categorization. As the manufacturing of NMs and industrial uses grow, so does their demand. The purpose of this review is to compare synthetic and naturally occurring nanoparticles and nanostructured materials to determine their nanoscale characteristics and to identify particular knowledge gaps related to the environmental application of nanoparticles and nanostructured materials. The paper review includes an overview of NMs' history and classifications and the many nanoparticles and nanostructured materials sources, both natural and manufactured. Furthermore, the many applications for nanoparticles and nanostructured materials.
42 citations
TL;DR: In this paper , the role of wastewater management in achieving sustainable development goals has been indicated, and a set of indicators (guideline) were proposed to improve the contribution of the wastewater treatment facility to the SDGs.
Abstract: The world is currently striving to achieve the globally adopted sustainable development goals (SDGs). Exploring the role of technology in achieving the SDGs is critical for the decision-makers and will allow them to overcome any possible trade-off. In this work, the role of wastewater management in achieving the SDGs has been indicated. The analysis shows that wastewater treatment could contribute to achieving 11 out of 17 SDGs. The major contribution came from its ability to increase water availability (SDG 2: zero hunger and SDG 6: clean water and sanitation), enhance human health worldwide (SDG 3: Good health and wellbeing), providing a new source of income for smallholder (SDG 1: no poverty and SDG 8: decent work and economic growth), converting waste to energy (SDG 7: affordable and clean energy, and SDG 9: industry, innovation and infrastructure) and reducing the environmental impact of wastewater (SDG 11: sustainable cities and communities, SDG 12: responsible consumption and production, SDG 13: climate action, and SDG 14: life below water). The challenges related to implementing and assessing these targets were discussed as well. A set of indicators (guideline) were proposed to improve the contribution of the wastewater treatment facility to the SDGs. This study emphasizes on the significant influence of wastewater treatment on the United Nations' SDGs and targets worldwide.
36 citations
TL;DR: In this paper, a review article has incorporated the recent advances in water purification methods using engineered nanoparticles and nanomembranes and the risk associated with use of nanoscale materials and the future aspects have also been highlighted in the article.
35 citations
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