Removal of harmful algae in natural water by semiconductor photocatalysis- A critical review. (September 2022)

• Record Type: Journal Article
• Authors: Mohan, Harshavardhan; Vadivel, Sethumathavan; Rajendran, Saravanan
• Is Part Of: Chemosphere. Volume 302(2022)
• Publication Date: 2022-09
• Subjects: Algae water -- Semiconductor -- Photocatalysis -- Treatment -- Inactivation -- Band gap; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2022.134827
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: Harmful Algal Blooms (HABs) have turned out to be a global occurrence owing to the detrimental phenomenon like eutrophication and global climate change caused by human activities. This newly emergent threat imposes a severe hazardous to public health, ecosystems and fishery-based economies. Rapid and exponential growth of certain delirious and toxic algal species shall be held causative to the formation of HABs. The potential disadvantages they pose, make it necessary the identification of efficient treatment methodologies. Photocatalysis has been identified as the most promising solution amongst all the identified and investigated methods, for the environmental and economic benefits beheld. Different treatment methodologies were evaluated and light has been thrown on the advantages beheld by photocatalysis over the other methods. Focus has been given to the different photocatalysts that have been so far put to use towards photocatalytic disinfection of HABs and algal toxins. This present study provides useful information on the application of the traditional and photocatalysis process for removal of HABs in water bodies. Moreover, the results revealed that photocatalysis method could cause potent inhibitory effect on growth of algae species and disrupted algal cells membranes to some extent. Finally, the conventional treatment techniques have been recognized to be insufficient for removal of HABs. However, the photocatalyst technology have been utilized mostly for the mineralization and neutralization of the algal pollutants without any harmful secondary pollutants. Graphical abstract: Image 1 Highlights: Novel covalently bonded composites and synthesised methods have been discussed. The rational synchronous methods for algae removal was proposed. Charge neutralization and enhanced adsorption mechanism play a role algae removal. Low concentration of personal care products increases the protein content of algae. Synergistic oxidation and adsorption by photocatalyst achieved algae removal.