Preparation, characterization and photocatalytic activity of activated charcoal from microalgae for photocatalytic degradation of rhodamine B dye

Abstract

The need to adopt measures that reduce the persistence of pollutants in the environment is notorious, in order to promote the correct disposal and treatment of effluents. This study aimed to prepare, characterize, and evaluate the photocatalytic activity of activated charcoal obtained from the residual biomass of Chlorella pyrenoidosa microalgae for Rhodamine B (RhB) dye degradation. The samples were characterized by X-ray diffraction, Fourier-transform infrared spectroscopy, N2 porosimetry, and zeta potential. To evaluate the photocatalytic activity, experiments were carried out in a stirred batch reactor. The activated charcoal prepared from microalgae biomass showed the better photocatalytic activity in the degradation of the RhB dye of 75.5% under ultraviolet radiation (k=0.0121 min-1), and 66.5% under visible radiation (k=0.0091 min-1), while the commercial ZnO achieved 92.5% (k=0.0158 min-1) and 16.6% (k=0.0032 min-1) for ultraviolet and visible radiation, respectively. Moreover, the activation/carbonization process used for the preparation of activated charcoal from microalgae biomass promoted changes in the structural, textural, and catalytic properties of the prepared samples.

Potential Application of Alternative Materials for Organic Pollutant Removal

“…Figure 2 represents the diffractogram pattern of the AC-SC, showing a crystalline structure of the biochar prepared using an active agent (ZnCl 2 ). Thus, wurtzite-type hexagonal crystalline structures of the ZnO with characteristic peaks and planes were indicated at 31.3° (1 0 0), 33.8° (0 0 2), 35.8° (1 0 1), 46.9° (1 0 2), 56.3° (1 1 0), 62.5° (1 0 3), 66.2° (2 0 0), 67.3° (1 1 2), and 68.5° (2 0 1), according to the Joint Committee on Powder Diffraction Standard (JCPDS-nº 01-075-0576), coming from the precursor of the chemical activation ZnCl 2 (Figueiredo et al, 2020;Zidi et al, 2019).…”

Heterogeneous Fenton-like catalytic degradation of phenazine dye over CeO2 (CP-2) nanoscale powder

“…Amongst them, iron minerals are relatively less priced and can be separated magnetically from the reaction medium [43]. Applications o f Fe-rich bentonite [44], fly ash-based catalysts [45], and molybdenum carbide doped with nanostructured nickel [46] have been reviewed in detail.…”

Síntese Conjunta do compósito nanoestruturado Fe2O3-SnO2 pelo método poliol e seu desempenho fotocatalítico no descoramento da rodamina-B

“…Os estudos sobre a funcionalidade de nanocompósitos formados de óxidos semicondutores têm mostrado que muitas das propriedades podem ser aprimoradas, em função do método de síntese empregado e associação com distintos óxidos e metais. Dentre estes estudos, destacam-se aqueles sobre as reações de fotocatálise para a remediação, por meio do descoramento e da degradação de corantes orgânicos, como a Rodamina-B [4], corante largamente utilizado na indústria têxtil e largamente encontrado em aquíferos atingidos por efluentes [5][6][7][8][9][10].…”