Calcium alginate gel and hard beads for the removal of total organic acid anions and heavy metal ions from industrial lean methyldiethanolamine solvent

Phytoconstituent analysis, anti-inflammatory, antimicrobial and anticancer effects of nano encapsulated Convolvulus arvensis L. extracts

BACKGROUND

The Convolvulus genus is distributed all over the world and has a long history in traditional medicine. As nanotechnology expands its reach into areas like drug delivery and biomedicine, this study intends to assess the potential of Convolvulus arvensis L. extracts as anti-bacterial, anti-inflammatory and anti-cancer agents, along with chemical profiling of the methanolic (MeOH) extract active ingredients.

METHODS

The chemical composition of an 85% MeOH extract was investigated by liquid chromatography with an electrospray source connected to mass spectrometry (LC-ESI-MS). Both the 85% MeOH extract and n-butanol fraction of C. arvensis were loaded for the first time on alginate/chitosan nanoparticles. The 85% MeOH extract, n-butanol fraction and their loaded nanoparticles were tested for their cytotoxicity, anticancer, anti-inflammatory and antibacterial activity (against pathogenic bacteria, E. coli and S. aureus).

RESULTS

The chemical investigation of 85% MeOH extract of C. arvensis underwent LC-ESI-MS analysis, revealing twenty-six phenolic substances, of which 16 were phenolic acids, 6 were flavonoids, 1 glycolipid, 1 sesquiterpene and 2 unknown compounds. The FT-IR spectra confirmed the encapsulation of the 85% MeOH extract and n-butanol fraction onto alginate/chitosan nanoparticles and small size obtained by TEM maintained them nontoxic and enhanced their anti-inflammatory activity (the IC50 was decreased from 1050 to 175 µg/ml). The anti-cancer activity against HepG2 was increased and the cell viability was decreased from 28.59 ± 0.52 to 20.80 ± 0.27 at a maximum concentration of 1000 µg/ml. In addition, the MIC of encapsulated extracts was decreased from 31.25 to7.78 µg/ml in E. coli (Gm-ve) and from 15.56 to 7.78 µg/ml in S. aureus (Gm + ve) bacteria.

CONCLUSION

Both alginate and chitosan are excellent natural polymers for the encapsulation process, which affects positively on the bioactive constituents of C. arvensis extracts and improves their biological properties.

Recent advances in cellulose- and alginate-based hydrogels for water and wastewater treatment: A review

From the environmental perspective, it is essential to develop cheap, eco-friendly, and highly efficient materials for water and wastewater treatment. In this regard, hydrogels and hydrogel-based composites have been widely employed to mitigate global water pollution as this methodology is simple and free from harmful by-products. Notably, alginate and cellulose, which are natural carbohydrate polymers, have gained great attention for their availability, price competitiveness, excellent biodegradability, biocompatibility, hydrophilicity, and superior physicochemical performance in water treatment. This review outlined the recent progress in developing and applying alginate- and cellulose-based hydrogels to remove various pollutants such as dyes, heavy metals, oils, pharmaceutical contaminants, and pesticides from wastewater streams. This review also highlighted the effects of various physical or chemical methods, such as crosslinking, grafting, the addition of fillers, nanoparticle incorporation, and polymer blending, on the physiochemical and adsorption properties of hydrogels. In addition, this review covered the alginate- and cellulose-based hydrogels' current limitations such as low mechanical performance and poor stability, while presenting strategies to improve the drawbacks of the hydrogels. Lastly, we discussed the prospects and future directions of alginate- and cellulose-based hydrogels. We hope this review provides valuable insights into the efficient preparations and applications of hydrogels.

Identification and Quantification of Organic Contaminants and Evaluation of Their Effects on Amine Foaming in the Natural Gas Sweetening Industry

Contamination is a leading cause of corrosion, foaming, and amine-absorption capacity limitation, predominantly foaming. There is currently an urgent need to identify the sources of amine foaming and eliminate them or reduce their impacts. Gas chromatography-mass spectrometry (GC-MS) and a sample pretreatment method were developed to identify and quantify the organic contaminants. Linear hydrocarbons (C₁₂-C₂₂), long-chain carboxylic acids and esters, alcohol ethoxylates, and benzene derivatives were detected, characterized, and quantified in amine solutions. Furthermore, the effects of the contaminant concentrations on foaming behavior were also investigated by adding those contaminants. The results reveal that the main issue of foaming is due to the presence of unsaturated fatty acids and alcohol ethoxylates, even with a small amount of 10 ppm, whereas benzene derivatives like methylpyridine, quinoline, methyl naphthalene, benzyl alcohol, octahydroacridine, and linear hydrocarbons have little effect on amine foaming, even with an amount up to 2000 ppm. Therefore, it is necessary to monitor the existence and content of these surface-active contaminants.

Effective Removal of Cyanide and Heavy Metals from an Industrial Electroplating Stream Using Calcium Alginate Hydrogels

A real electroplating wastewater, containing 51,190 mg/L of free cyanide (CNf), 4899 mg/L of Ni and 1904 mg/L of Cu, was treated with calcium alginate hydrogel beads (CAB), pure or impregnated with biodegraded grape marc (EBGM) or activated carbon (EAC) in order to reduce the elevated load of toxic pollutants below the regulatory limits. It was evaluated the effect of increasing the amount of bioadsorbent as well as the influence of two successive adsorption cycles in the removal efficiency of pollutants. The most favourable sorption conditions onto CAB provided removal percentages of 85.02% for CNf and between 93.40-98.21% for heavy metals regarding the raw wastewater. The adsorption capacity of each pollutant onto CAB was considerably increased during the first 30 min of contact time, but after achieving the equilibrium, the following sorption capacities were obtained: 1177, 107.3, 39.5 and 1.52 mg/g for CNf, Ni, Cu and Zn, respectively. The kinetic adsorption of pollutants onto the CAB was adjusted to different kinetic models, observing that kinetic data agreed with the pseudo-second-order model. The information about intraparticle diffusion mechanisms in the bioadsorption process was also interpreted.