Eco-friendly Nano-adsorbents for Pollutant Removal from Wastewaters

Abstract

Major changes of the environment are caused by the presence of pollutants in air, soil, and wastewaters. From these, a major attention is accorded to the industrial wastewaters, because can contain simultaneous different types of pollutants such as heavy metals, anions, dyes, phenols, pesticides, drugs, etc. For wastewater treatment, consecrated methods such as adsorption, photocatalysis, membrane separation, etc. can be used, adsorption being considered one of the most favorable techniques. In the last years, an increase in interest was observed in nanoadsorbent materials with low cost. Ecofriendly nano-adsorbents include the materials obtained from industrial wastes, agricultural sources, and by-products, recognized as low-cost sources. These nano-adsorbents, obtained by "green technologies," have adsorption capacities, comparable to the expensive adsorbents (modified chitosan, activated carbon, complex inorganic composites, etc.).

Fly Ash Coated with Magnetic Materials: Improved Adsorbent for Cu (II) Removal from Wastewater

“…This fact was observed when the fly ash was treated with NaOH and H 2 SO 4 [ 15 , 26 ]. Additionally, other researchers have obtained similar results [ 12 , 24 ].…”

“…Fly ash is preferred as an adsorbent since it is a cheap and highly-available material [ 24 , 25 ]. On the other hand, there are highlights that the presence of fly ash discharged from thermal power plants by the burning of coal represents a big environmental issue [ 26 , 27 , 28 , 29 ].…”

Zn/La Mixed Oxides Prepared by Coprecipitation: Synthesis, Characterization and Photocatalytic Studies

“…The scientists' concern for the green elimination of various persistent organic contaminants from wastewaters resulted, among others, in a high interest paid for obtaining highly performant materials for the photocatalytic reactions mediated by semiconductive solids, by oxidation reactions [1][2][3][4]. This class of reactions belong to the so-called AOPs (Advanced Oxidation Process), being very popular especially for the purification of wastewaters from low amounts of pesticides, drug compounds, dyes, disinfectants and other very stable and non-biodegradable chemicals, which depreciate the water quality, despite their ppm-range concentrations [5,6].…”

Magnetic Solid-Phase Extraction of Cadmium Ions by Hybrid Self-Assembled Multicore Type Nanobeads

“…Pollution with heavy metals (cadmium, copper, nickel, lead, chromium) from different industrial wastewaters represents a serious problem for the environment and human health [ 1 ]. Nanotechnology addresses the continuous development of solutions to the existing environmental problems and preventive measures for future problems.…”