Recently, a great attention has been given for applying a low-cost and effective adsorbents instead of expensive and dangerous chemical materials as a promising approach to treat wastewater. In this work, residue powder of brown macroalga Padina gymnospora (RPG), after extracting most of its active components by 70% methanol, was used as an adsorbent material for wastewater treatment. This work also reduces the costs of residue disposal. The adsorption ability of RPG is studied for removing Cd2+ and Cr3+from wastewater. We investigated metal adsorption isotherms and kinetics, the effect of initial metal concentration, contact time, adsorbent dosage, temperature, pH and the RPG reusability on metal ions removal. The results showed that the removal % generally increases with decreasing concentration of metal ions. RPG has higher metal removal percentages reaching 96.2% and 78.8% for Cd2+ and Cr3+, respectively, with a maxiumum adsorption capacity of 96.46 and 31.52 mg/g for Cd 2+ and Cr3+,respectively at pH 6.2, 50 mg, 25 °C and initial metal concentration of 100 mg/L. The metal ions removal % increased by increasing the dosage of adsorbent and it decreased after a certain limit. The metal removal % slightly changes with increasing temperature for Cd2+ and decreased at high-temperature for Cr3+. The adsorption increased with increasing pH value from 3 to 5, and decreases at pH value of 6.2 then it increased again at pH 8. The removal % and adsorption capacity at pH 8 reaches 99.58%, 99.65%, 99.85 mg/g and 39.86 mg/g for Cd2+ and Cr3+, respectively. The results also showed that RPG can be reused several times for metal ions removal. In addition, Tempkin isotherms and pseudo-second-order kinetic fit the adsorption of Cd2+ and Cr3+ well.

Chitosan derivative nano-nitro-acetophenone was prepared by Schiff base reaction. The nano nitro-acetophenone was impregnated with CuO-CeO₂-Al₂O₃and CuO-CeO₂-Fe₂O₃ nanocomposite to fabricate new organic-metal oxides nanocomposite of Chitosan-4-nitroacetophenone/CuO-CeO₂-Al₂O₃ (NCCA) and Chitosan-4-nitroacetophenon/CuO-CeO₂-Fe₂O₃ (NCCF). The new organic-metal oxides nanocomposite were prepared by wet impregnation technique, characterised by XRD, TEM, SEM, FTIR and TGA analysis, and used as an adsorbent for industrial disperse red 60 dye from wastewater. Dye adsorption isotherms, kinetics, thermodynamics, the effect of contact time and initial dye concentration, temperature, pH and adsorbent dosage were investigated. The reusability of NCCF and NCCA on dye removal was also studied. The results indicated that the dye removal% generally increased with decreasing dye initial concentration. The removal % decreased by increasing NCCF dosage while it increase by increasing the NCCA dosage from 0.05 to 0.1 g and after that it decreases again. The dye removal % increase with increasing temperature from 20°C to 80°C for NCCF adsorbent, while, it decreased at high temperature for NCCA adsorbent. Also, it decreased with increasing the initial pH of the solution from 2 to 8 for NCCF adsorbent. For NCCA adsorbent the percentage removal was increased with increasing the initial pH of the solution from 2 to 4 and after that it decrease again. The results showed also that NCCA was good reusable adsorbent, while, NCCF is not preferred for reuse for the same propose. The adsorption isotherm of dispersed red 60 dye onto NCCF and NCCA almost agreed with Langmuir isotherm and pseudo-second-order kinetics. The maximum amount of adsorbed dye is 92.8 and 88.5 mg/g onto NCCF at pH 2 and NCCA at pH 4, respectively. The thermodynamic results showed that the adsorption of disperse red 60 dye onto NCCF and NCCA is spontaneous, physical and endothermic adsorption process.

Palm date pits as a source of bioactive chemicals have received only a limited amount of attention. This study was conducted to determine the bioactive components of Ajwa date pits, as well as their antibacterial and antimutagenic activities. Therefore, chromatographic techniques were used to extract and isolate the phenolic compounds in date pits, which were further elucidated by using spectroscopic techniques (FTIR and NMR) for identification of most abundant bioactive metabolites. Data showed that the methanolic extract of date pits contained high levels of total phenols (17.38 mg GA/g) and flavonoids (5.324 mg QE/g). The HPLC analysis of date pits’ extract showed the presence of six phenolic compounds. Interestingly, there was a significant amount of gallic acid (11.85 mg GA/gFW), which was isolated via chromatography (thin layer chromatography) and identified by spectroscopic investigation (FTIR, MS, 1H, and 13C NMR). An inhibitory effect on Gram-positive and Gram-negative bacteria was observed for date pit gallic acid purified. S. aureus cell viability was completely inhibited at 200 µg/mL of acid for 6 h. Moreover, gallic acid was found to have a significant antimutagenic activity against Salmonella typhimurium at all tested concentrations, with a decrease in percent mutagenicity from 52 to 32 in the case of test substance TA98, and from 39 to 15 for test substance TA100 in terms of percent antimutagenicity. Gallic acid at a dose of 3000 g/plate had the greatest antimutagenic effect on S. typhimurium TA98, with the lowest toxicity. Overall, the bioactive properties of date pits’ extracts were investigated, with a particular attention to their chemical composition, biological activity, and pharmaceutical applications.