Low cost adsorbents such as P. australis have received considerable interest owing to their low cost and easy availability. The aim of the present study was the evaluation of the removal of chemical oxygen demand (COD), biological oxygen demand (BOD), total suspended and dissolved solids (TSS and TDS) using dried P. australis in influent wastewater to a wastewater treatment plant. The results of the COD and BOD concentration reduction with P. australis at optimum operating conditions were determined for maximum reduction and adsorption isotherms. The maximum reduction of COD, BOD, TSS and TDS concentrations under the optimum operating conditions was 92.27%, 93.89%, 94.38% and 91.61%, respectively. The results demonstrate that the new dried biosorbent is able to adsorb all the aforementioned contamination. It achieved an adsorption capacity for COD of 72.5 mg g⁻¹ and an adsorption capacity for BOD of 43.93 mg g⁻¹. The results were well fitted by the pseudo-second order model with R² = 0.984.

In the field of wastewater treatment, the need for efficient and sustainable solutions is perpetual. This study delves into the efficacy of attached growth systems, a burgeoning approach that capitalizes on microbial communities immobilized on various substrates, in addressing diverse wastewater treatment challenges. Biofilm reactors natural tendency to form structured communities on solid surfaces. By investigating the geometry of biocarriers in these systems, this study evaluates the factors influencing treatment efficiency. We employed experimental trials, focusing on media length and surface area, utilizing high-density polyethylene (HDPE) tubing sections of varying dimensions. Results indicate that perforated biocarriers outperform hollow biocarriers, showcasing superior organic matter removal efficiencies, attributed to their larger surface area and enhanced mass transfer capabilities. Additionally, biofilm growth was found to correlate directly with surface area, as greater attachment sites foster denser and more resilient biofilms. The concentration of microbial activity towards the edges of the media suggests their pivotal role in nutrient removal. Overall, this study underscores the significance of biocarrier geometry in enhancing treatment performance and advancing the sustainability of attached growth-based wastewater treatment processes.

Humic acid (HA)-clay convoluted are well identified for their contribution to environmental processes. Upflow column filter experiments were performed in this study to scrutinize humic acid in simulated synthetic aqueous solution (SSAS) removal using kaolin, montmorillonite and fe-modified montmorillonite under different experimental conditions. The results showed that humic acid removal was higher in fe-modified montmorillonite clay than in kaolin and montmorillonite clays at optimum experimental conditions. The results show that the optimum removal efficiency of HA using femodified montmorillonite was 99 % for humic acid from simulated synthetic aqueous solution (SSAS) when pH = 1, flow rate = 15 ml/min, retention time = 90 min and initial HA concentration = 1 ppm. This efficiency was decreased with increasing of pH, flow rate and initial humic acid concentration while the removal efficiency increased with increasing retention time. This indicates that humic acid removal can be enhanced through the surface charge modification of montmorillonite, by replacing the natural interlayer cations of montmorillonite with polymeric Fe species, the properties of clay surfaces can be modified, and this allows them to interact with both organic and inorganic pollutants dissolved in water. The results of reusability of fe-modified montmorillonite clay obtained that only a slight loss in % HA removal efficiency was observed after five cycles of consecutive reusability, demonstrating that fe-modified montmorillonite was high-performance recyclable filter media for the removal of HA. Results of the experimental data show that the best empirical correlation achieved the most fitting of predicted % removal of HA from (SSAS) using fe-modified montmorillonite clay that gives the maximum value of (R2 = 0.9998). Fe-modified montmorillonite is potential efficient filter media to be used as possible future promising development in filtration field.