Starch engineered with Moringa oleifera seeds protein crosslinked Fe3O4: A synthesis and flocculation studies

Natural-based coagulants/flocculants as sustainable market-valued products for industrial wastewater treatment: a review of recent developments

Industrial wastewater is categorized as a voracious consumer of fresh water and a high-strength source of pollution. Coagulation-flocculation is a simple and cost-effective technique for removing organic/inorganic compounds and colloidal particles from industrial effluents. Despite the outstanding natural properties, biodegradability, and efficacy of natural coagulants/flocculants (NC/Fs) in industrial wastewater treatment, their significant potential to remediate such effluents is underappreciated, particularly in commercial scale applications. Most reviews on NC/Fs focused on the possible application of plant-based sources such as plant seeds, tannin, certain vegetables/fruit peels, and their lab-scale potential. Our review expands the scope by examining the feasibility of using natural materials from other sources for industrial effluent decontamination. By analyzing the latest data on NC/Fs, we identify the most promising preparation techniques for making these materials stable enough to compete with traditional options in the marketplace. An interesting presentation of the results of various recent studies has also been highlighted and discussed. Additionally, we highlight the recent success of using magnetic-natural coagulants/flocculants (M-NC/Fs) in treating diverse industrial effluents, and discuss the potential for reprocessing spent materials as a renewable resource. The review also offers different concepts for suggested large-scale treatment systems used by MN-CFs.

Optimization of accelerated aqueous ethanol extraction to obtain a polyphenol-rich crude extract from rambutan (Nephelium lappaceum L.) peel as natural antioxidant

An accelerated solvent extraction method was used to recover polyphenol-rich crude extract from rambutan (Nephelium lappaceum L.) peel, a waste product from the canning industry. The influence of extraction parameters including temperature, extraction time and ethanol concentration on extraction yield, total phenolic content, total anthocyanin content, and ABTS antioxidant activity was investigated. A Box-Behnken design and response surface methodology were used to optimize the extraction process. Optimal conditions were obtained at temperature, extraction time, and ethanol concentration of 60 °C, 34 min, and 54 vol%, respectively. These optimum conditions gave 333.01 ± 5.84 mg gallic acid/g, 318.28 ± 5.56 mg cyanidin-3-O-glucoside/g, and 3.05 ± 0.04 mmol Trolox/mg for total phenolic content, total anthocyanins content, and ABTS activity, respectively with extraction yield of 28.68 ± 1.48 wt%. Important active compounds found in the extract were geraniin, ellagic acid, shikimic acid and corilagin. Crude extract concentrations of 50-500 mg/kg retarded linoleic acid oxidation but efficacy was lower than synthetic antioxidants at 200 mg/kg. The current findings indicated that accelerated aqueous ethanol extraction was an effective method for the recovery of a crude extract rich in polyphenols from rambutan peel with the potential to be used as a natural antioxidant.

Enhanced treatment of organic matters in starch wastewater through Bacillus subtilis strain with polyethylene glycol-modified polyvinyl alcohol/sodium alginate hydrogel microspheres

Starch wastewater is a wide range of environmental issues with organic pollutants. A high efficiency and stability hydrogel-organic degradation system was designed via Bacillus Subtilis with Polyethylene glycol (PEG)-modified Polyvinyl alcohol (PVA)/Sodium alginate (SA) hydrogel microspheres. Bacillus subtilis was immobilized on the surface or inside of PEG-modified PVA/SA hydrogels microspheres via physical adsorption. Results showed PEG-modified PVA/SA microspheres had an effect of adsorption on Bacillus subtilis with enhancing bearing rate to 54.22% compared to the blank control group. The effect of microspheres on degradation was remarkable in simulation starch wastewater with a maximum COD removal rate of 93.35% and compared in reality starch wastewater with 90.02% under the optimal condition of pH = 6, 35℃, 20% dosage, 180 rpm. This novel biological method on starch wastewater enhanced tolerance of microorganisms and degradation effect, reflecting safety, effectiveness, and economy with great significance to environmental protection.