This project investigated the relative efficiencies of three pilot-scale constructed columns for enhancing drainage wastewater treatment processes to ensure compliance with Egyptian and international water quality criteria. In this investigation, basic materials (sand and gravel) and variable natural clay minerals zeolite (Z), diatomite (D) and bentonite (B) were utilized as packing materials to build up a Z column (ZC), D column (DC) and B column (BC), respectively. The three columns’ ability to remove pollutants from waste water for re-use in irrigation was investigated throughout one year (12 trials). The results revealed that the influent water had 211 mg/L total suspended solids, 6.09 mg/L total nitrogen, 36.67 mg/L biochemical oxygen demand, 56 mg/L chemical oxygen demand, 1700 mg/L total dissolved solids, 0.97 mg/L copper (Cu²⁺), 1.12 mg/L iron (Fe²⁺), 1.07 mg/L manganese (Mn²⁺), 1.02 mg/L lead (Pb²⁺), 1.05 mg/L zinc (Zn²⁺), and 46 × 10³ CFU/mL fecal coliforms. These parameters were higher than the values permitted by Egyptian and international licenses. The range of removal efficiency of these pollutants by ZC was 96–21%, by BC was 99–29.8%, and by DC was 99–19.80%. Regeneration studies for the spent adsorbents demonstrated that the percentages of pollutant removal were sufficiently high. The treated effluent produced by the three columns was suitable for irrigation purposes, especially at a contact time of four hours, with the order for column treatment efficiency being BC ˃ DC ˃ ZC. Treated water was classified for irrigation suitability according to the Agrifood Water Quality Index (AFWQI) as marginal from the ZC, very good from the DC, and excellent from the BC. Treatment of such drainage water using the BC and DC appears feasible, because the process is easily operated and leads to final treated effluent of high quality for agricultural uses. The economic cost also confirms the feasibility of this treatment.

The novelty of the current article is to investigate the adsorption potential of the Egyptian natural and activated bentonite (Na-bentonite) to inorganic and organic phosphorus (IP, OP) in aqueous media. The natural bentonite (NB) was activated to Na-bentonite (Na-B) by a new facile method within 2 h. NB and Na-B were also characterized using XRD, XRF, BET ESM, and FT-IR. The batch experiment has been employed to select the ideal conditions for the removal of inorganic and organic phosphorus (IP, OP) from aqueous solutions. The findings clearly showed that the Na-bentonite is enriched with sodium in the form of Na-montmorillonite with a higher specific area 138.51 m²/g than the value for the natural bentonite 74.21 m²/g. The batch experiment showed maximum absorption for both IP and OP adsorbents occurred at an equilibrium pH = 6, contact time of 40 to 50 min, 40 °C temperature, and a dose rate of 2 mg/L and 1 mg/L, respectively. The equilibrium data displayed better adjustment to Langmuir than the Freundlich, Temkin, and Dubinin-Radushkevich isotherms and adsorption kinetics followed the pseudo-second-order-type kinetic, and the parameters of thermodynamics reveal that adsorption occurs spontaneously and exothermic nature. Na-bentonite proved to be more efficient in removing target material than natural bentonite. The spent bentonites were easily regenerated by chemical methods.

The examination of the performance of raw and immobilized S. (Saccharomyces) cerevisiae in the simultaneous abatement of metal ions from wastewater effluent is the focal point of this article. The optimal storage time for raw and immobilized S. cerevisiae, during which they can be utilized, was estimated. The outcomes revealed that as the initial metal ion concentrations increased, the adsorption capacity improved, while the removal efficiency of S. cerevisiae yeast cells decreased, with the highest uptake obtained at the optimal conditions: pH = 5.0, 2.0 g S. cerevisiae/L, 25 °C, and a contact time of 25 min. The maximum adsorption capacities (q_max) for Pb(II), Cd(II), and Ni(II) ions are shown by Langmuir at 65, 90, and 51 mg/g, respectively. It was discovered that the metal ions’ biosorption reactions were spontaneous and were fitted by the pseudo-second-order model. The mechanisms of the metal ions’ abatement were explained by using XRD (X-ray diffraction), FTIR (Fourier transform infrared spectroscopy), (BET) Brunauer–Emmett–Teller, and TEM (transmission electron microscopy) outputs. EDTA and citric acid can eliminate more than 70 ± 4 and 90 ± 5% of the adsorbed ions, respectively. The experiment of storage demonstrated that the immobilized S. cerevisiae was more stable for 8 months than the raw yeast.