The controversy related to the environment pollution is increasing in human life and in the eco-system. Especially, the water pollution is growing rapidly due to the wastewater discharge from the industries. The only way to find the new water resource is the reuse of treated wastewater. Several remediation technologies are available which provides a convenience to reuse the reclaimed wastewater. Heavy metals like Zn, Cu, Pb, Ni, Cd, Hg, etc. contributes various environmental problems based on their toxicity. These toxic metals are exposed to human and environment, the accumulation of ions takes place which causes serious health and environmental hazards. Hence, it is a major concern in the environment. Due to this concern, the significance of developing technology for removing heavy metals has been increased. This paper contributes the outline of new literature with two objectives. First, it provides the sketch about treatment technologies followed by their heavy metal capture capacity from industrial effluent. The treatment performance, their remediation capacity and probable environmental and health impacts were deliberated in this review article. Conclusively, this review paper furnishes the information about the important methods incorporated in lab scale studies which are required to identify the feasible and convenient wastewater treatment. Moreover, attempts have been made to confer the emphasis on sequestration of heavy metals from industrial effluent and establish the scientific background for reducing the discharge of heavy metals into the environment.

Efficient techniques for the removal of toxic heavy metals from aquatic environment: A review

Spinel ferrite magnetic adsorbents: Alternative future materials for water purification?

Heavy metals are discharged into water from various industries. They can be toxic or carcinogenic in nature and can cause severe problems for humans and aquatic ecosystems. Thus, the removal of heavy metals from wastewater is a serious problem. The adsorption process is widely used for the removal of heavy metals from wastewater because of its low cost, availability and eco-friendly nature. Both commercial adsorbents and bioadsorbents are used for the removal of heavy metals from wastewater, with high removal capacity. This review article aims to compile scattered information on the different adsorbents that are used for heavy metal removal and to provide information on the commercially available and natural bioadsorbents used for removal of chromium, cadmium and copper, in particular.

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Heavy metal removal from wastewater using various adsorbents: a review

Application of spinel ferrite nanoparticles in water and wastewater treatment: A review

Water pollution is one of the global challenges that society must address in the 21st century aiming to improve water quality and reduce human and ecosystem health impacts. Industrialization, climate change, and expansion of urban areas produce a variety of water pollutants. In this work, we discuss some of the most recent and relevant findings related to the release of heavy metals, the possible risks for the environment and human health, the materials and technologies available for their removal. Anthropogenic activities are identified as the main source of the increasing amounts of heavy metals found in aquatic environments. Some of the health hazards derived from repeated exposure to traces of heavy metals, including lead, cadmium, mercury, and arsenic, are outlined. We also give some perspectives about several techniques used to detect heavy metals, as well as about the factors that could affect the contaminant removal. The advantages and drawbacks of conventional and non-conventional heavy metal removal methods are critically discussed, given particular attention to those related to adsorption, nanostructured materials and plant-mediated remediation. Some of the commercial products currently used to eliminate heavy metals from water are also listed. Finally, we point out some the requirements and opportunities linked to developing efficient methods for heavy metal removal, such as the ones that exploit nanotechnologies.

Heavy metal water pollution: A fresh look about hazards, novel and conventional remediation methods

In recent years, adsorption has displayed promising and effective results as a treatment technology for water and wastewater by industries. In the process, a number of adsorbents have been synthesized and applied for the treatment of pollutants such as metals, dyes, pharmaceutical products in solutions. However, for adsorption to be unconditionally adopted by industries, a few obstacles such as high capital cost, difficult segregation of adsorbent from solution, and complex synthesis processes need to be addressed. The removal of suspend adsorbents in wastewater from a continuous flow system is a challenge which if addressed properly would enable us to recover the spent adsorbent efficiently. The spent adsorbents can then be regenerated and used again by the industries thereby leading to reduced capital investment. Therefore, studies have been carried out aiming at the incorporation of magnetism in such adsorbents to aid their removal from wastewater. This review aims to comprehensively list and discuss adsorbents which exhibit magnetic properties and their adsorption behaviour under diverse conditions. The literature survey presented in this paper renders evidence to the good potential of magnetic adsorbents to remove various pollutants from wastewater. However, the practical utility of such adsorbents needs to be explored before they can be commercially applied.

Magnetic adsorbents for the treatment of water/wastewater—A review

With an increase in demand of freshwater and depleting water sources, it is imperative to switch to seawater as a regular source of water supply. However, due to the high total dissolved solid content, it has to be desalinated to make it drinkable. While desalination technologies have been used for many years, mass deployment of such technologies poses a number of challenges like high energy requirements as well as high negative environmental impact through side products and CO2 emissions. The purpose of this paper is to present a sustainable technology for desalination. Forward osmosis, an emerging technology, is compared with the other commonly used technologies worldwide, namely, multieffect distillation, multistage flash distillation, and reverse osmosis as well as other emerging technologies like vapour compression, solar humidification dehumidification, nanofiltration, and freezing desalination. As energy consumption and associated greenhouse gas emissions are one of the major concerns of desalination, this paper concludes that forward osmosis is an emerging sustainable technology for seawater desalination. This paper then presents the challenges involved in the application of forward osmosis in India and presents a plant setup. In the end, the cost comparison of a forward osmosis and reverse osmosis plant has been done and it was concluded that forward osmosis is economically better as well.

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Forward Osmosis in India: Status and Comparison with Other Desalination Technologies

This paper explores the potential of French green beans (Phaseolus Vulgaris) and Lotus Stem (Nelumbo Nucifera) as potential low-cost adsorbents for the removal of Methylene Blue from wastewater. The studies were conducted with variation in parameters of pH, biomass concentration, contact time and initial dye concentration. The nature of the possible adsorbent and metal ion interactions was examined by the FTIR technique. Adsorption of Methylene Blue onto French green beans could be described by the Freundlich model while Langmuir model with a maximum adsorption capacity of 62.5 mg/g was followed by Lotus Stem. The experimental data was modelled using pseudo-first and pseudo-second-order kinetic equations. Adsorption kinetics could be described by pseudo-second order equation.

Dhruv Mehta

Papers

Magnetic adsorbents for the treatment of water/wastewater—A review

Forward Osmosis in India: Status and Comparison with Other Desalination Technologies

Biosorption of Methylene Blue from an aqueous solution using French green beans and Lotus Stem