Search

The Cladophora and Spirogyra algae examined in this study belong to the Chlorophyta division. Macro filamentous algae, which are widespread in fresh water worldwide, have high potential to be developed as biological materials because of their large biomass and availability. In this study, we collected fresh algae from where they grew and produced bleached and unbleached algae powder using to adsorb Cu(II) ion solution. After the biosorption process, we noted the following four significant findings: (i) The functional groups and binding sites in the produced algae powder were affected, causing variations in the amount of copper adsorbed. The variations resulted from differences in the cell structure, the cell wall thickness of Cladophora and Spirogyra algae, cell composition, and the types and amount of epiphytic algae. (ii) Common bleaching procedures using glacial acetic acid influenced the binding sites of the functional groups and the biomass of the produced powder. Because of the bleaching, the amount of copper adsorbed by the Cladophora powder declined by 14.2%, and by 15.7% for Spirogyra powder. (iii) The carbonyl and hydroxyl groups of unbleached powder were the main elements affected during the bleaching procedures. Examining whether the biosorption experiment results fit Gin’s biosorption model, we found that the biosorption amount and equilibrium reaction of the two bleached algae powders were inferior to that of the unbleached algae powders. (iv) The bleaching procedure using glacial acetic acid was not suitable for producing algae powder to use as an adsorbent for metal ions.

The Cladophora genus comprises macro benthic green algae, widely distributed in estuaries, rivers, and lakes around the world. It is often a dominant species and influences environmental and ecological systems. Cladophora is a biological material with great development potential due mainly to its significant biomass and the ease with which it can be harvested. Furthermore, because it can live on various carriers or vectors, the growth conditions of Cladophora can affect the group to which it belongs. To investigate the growth of the Cladophora group in the natural environment, this study endeavored to (1) observe the biomass accumulation of Cladophora glomerata on varying substrates, (2) determine whether substrate roughness has an impact on the attachment of C. glomerata, and (3) identify the relationship between the attachment of pioneer diatoms and C. glomerata. Five types of substrate were selected (glass slide, glazed tile, marble, unglazed tile, and wood) and placed in the natural habitat of C. glomerata, a sub-tropical river. After thirty days, unglazed tile produced the largest biomass of 2332.2 dry weight mg/m2, followed by wood (1744.3 dry weight mg/m2), marble (158.1dry weight mg/m2), glass slide (90.7dry weight mg/m2), and glazed tile(36.3 dry weight mg/m2). The results of this study indicate that the type and roughness of the substrate both influence the attachment of C. glomerata and the subsequent development of its population. The existence of biofilm formed by pioneer diatoms on the substrate is also beneficial to the epiphytic growth of C. glomerata. Moreover, the development of pioneer diatoms is associated with the type of substrate and its silicon content.

The Cladophora genus comprises macro benthic green algae, widely distributed in fresh and salt water around the world. This study employed C. glomerata and C. vagabunda to observe changes in the thickness of the mucilage layer formed by extracellular polymeric substance (EPS) and the number of epiphytic algae on the Cladophora species in different tidal reaches near the mouth of a river. Through a cultivation experiment, we observed the influence of salinity on the thickness of mucilage layers and the number of epiphytes on these two algal species. We discovered that the growth of C. glomerata is extremely sensitive to salinity; when salinity exceeds 1.0‰, a significant increase in EPS is induced, thickening the extracellular mucilage layer and affecting the attachment of epiphytes. Due to the wide distribution of C. glomerata, the sensitivity of this algal species to salinity can be employed as a biological indicator of variations in salinity.

The Cladophora and Spirogyra genera are classified within the green algae division. Species belonging to these genera comprise large filamentous algae, possess significant biomass, and are found in freshwater around the world. These characteristics give Cladophora and Spirogyra high potential to be developed as biological materials. For this study, we harvested fresh Cladophora and Spirogyra and produced algae powder using two of conventional procedures: with pigment extraction and without pigment extraction. The resulting algae powders were subjected to Pb(II) biosorption, and the differences in biosorption rates were subsequently analyzed. Our study found the following: (i) significant differences in cell structure, cell wall thickness, the type and content of cell composition, and the quantity of epiphytes between Cladophora and Spirogyra. This variation influenced the functional groups within the resulting algae powders and their binding sites, which further led to different levels of Pb(II) adsorption. (ii) Glacial acetic acid, a compound commonly employed in pigment extraction procedures, affected the functional groups and the binding sites of the resulting algae powders. For Cladophora algae powder, Pb(II) biosorption was reduced by 16.6 %; whereas for Spirogyra algae powder, Pb(II) biosorption was reduced by 19.8 %. (iii) The pigment extraction procedure exerted the most significant influence on the carbonyl groups and hydroxyl groups in algae powder. (iv) The pigment extraction procedure is not suitable for the preparation of algae powders which will be used for metal ion biosorption.