Removal of molybdate and vanadate ions by a copolymer adsorbent in a ultrafiltration system

An Overview to Technical Solutions for Molybdenum Removal: Perspective from the Analysis of the Scientific Literature on Molybdenum and Drinking Water (1990–2019)

A bibliometric analysis using the Scopus database was performed to investigate the research documents published from 1990 to 2019 in scientific sources related to molybdenum in drinking water and determine the quantitative characteristics of the research in this period. The results from the analysis revealed that the number of publications was maintained at a regular production of around 5 papers per year until 2009, followed by a fast linear increase in the production in the period from 2010 to 2016 (29 papers in 2016), but the scientific production regarding this topic was reduced in 2017 and 2018 to recover the production obtained in 2016 once again in 2019. The total contribution of the three most productive countries (USA, China and India, respectively) accounted for around 50% of the total number of publications. Environmental Science was the most common subject (51.4% contribution), followed by Chemistry (26.7% contribution). The research efforts targeted toward the search for technical solutions for molybdenum removal from water are not as important as the ones focused on the identification of molybdenum-polluted water bodies and the analysis of the health effects of the intake of molybdenum. Nevertheless, examples of technological treatments to remove molybdenum from the aqueous solution include the use of adsorption and ion exchange; coagulation, flocculation and precipitation followed by filtration; membrane technologies and biological treatments.

Removal of Dyes by Polymer-Enhanced Ultrafiltration: An Overview

The current problem of contamination caused by colored industrial effluents has led to the development of different techniques to remove these species from water. One of them, polymer-enhanced ultrafiltration (PEUF), has been systematically studied in this mini review, in which research works from 1971 to date were found and analyzed. Dye retention rates of up to 99% were obtained in several cases. In addition, a brief discussion of different parameters, such as pH, interfering salts, type of polymer, dye concentration, and membrane type, and their influence in dye removal is presented. It was concluded from the above that these factors can be adapted depending on the pollutant to be remediated, in order to optimize the process. Finally, theoretical approaches have been used to understand the intermolecular interactions, and development of the studied technique. In this revision, it is possible to observe that molecular docking, molecular dynamics simulations, density functional theory calculations, and hybrid neural-genetic algorithms based on an evolutionary approach are the most usual approximations used for this purpose. Herein, there is a detailed discussion about what was carried out in order to contribute to the research development of this important science field.