Antibiotics are the most common compounds that are found in groundwater, surface water, drinking water and wastewater. Also, traces of these antibiotics found in sewage sludge, soil and sediments that caused concern to the environment. Besides, the emergence of antimicrobial resistance becomes the major health problem worldwide. Nonetheless, therapeutic used of antimicrobials in human and veterinary medicine contributes to the widespread of resistant microorganisms. On the other hand walnut shells are among the waste materials that have been suggested to have efficient sorbent alternatives. Due to its low ash content and been used as low cost sorbent for metal and oil removal.
Walnut shell activated carbon in removal of antibiotic
Advance treatment of wastewater confirming the positive results in lowering the presence of antibiotic residues. These include ozonation, membrane separation, advanced oxidation, reverse osmosis and nanofiltration. In which, the vast applicability of activated carbon in pollutants removal are always dependent on the conditions of raw materials. So, this particular research, the walnut shell has been used since it is a precursor material for activated carbon production. Moreover, the activated carbons ability to remove organic micro-pollutants lies on the solution and contaminants properties. Apparently, the absorption of antibiotic Metronidazole shows the conditions that maximize expected results.
The influence of temperature on the absorption capacity of antibiotic is slightly significant. As a result, the absorption capacity depends on the nature of the activated carbon and its chemical characteristics, morphology and solutes. Also, the nature of solutes affecting electronic density influences the interactions with the matrix of the absorbent. In addition, activated carbon is the most common process to remove dissolved organic and inorganic compounds. Its great flexibility in applications arises from physical and chemical properties on specifically treated carbon materials.
As a result, the absorption amount of organic compounds depends strongly on essential properties of the absorbent. However, it can be slightly affected by some variables like temperature, pH, ionic strength and contact time. Therefore, antibiotic shows positive effect on the interaction of the absorbed amount. So, activated carbon from walnut shell might represent a good agent in removing antibiotic residues.
Sources: Prepared by Joan Tura from ScienceDirect: Science of the Total Environment
Volume 646, 1 January 2019 Pages 168-176