In the practice of medicine, antibiotics are extremely important and are employed in the treatment of infections. A lot of antibiotics are consumed by humans and excreted via urine and feces into sewage systems and treatment plants. These are considered to be non-biodegradable, and over the years they accumulate in the aquatic environment. The presence of antibiotics in water resources causes the emergence of antibiotic-resistant bacteria, posing a serious threat to the health of human beings. Water bodies must be adequately treated before being discharged to prevent the spread of antibiotic resistance. In the present article, the sources of antibiotics and strategies used for their effective removal, such as ultrafiltration, microfiltration, nanofiltration, membranous biological reactor treatment, Advanced Oxidation Process (AOP), Reverse Osmosis (RO) and Nano sorbents, are discussed. Conventional wastewater treatment plants are not able to eliminate antibiotics deposition/resistance genes effectively and efficiently. In this regard, the adsorption method is the most effective way of removing antibiotics from wastewater from various sources.

Polyhydroxyalkanoates (PHAs) are storage granules found in bacteria that are essentially hydroxy fatty acid polyesters. PHA molecules appear in variety of structures, and amongst all types of PHAs, polyhydroxybutyrate (PHB) is used in versatile fields as it is a biodegradable, biocompatible, and ecologically safe thermoplastic. The unique physicochemical characteristics of these PHAs have made them applicable in nanotechnology, tissue engineering, and other biomedical applications. In this review, the optimization, extraction, and characterization of PHAs are described. Their production and application in nanotechnology are also portrayed in this review, and the precise and various production methods of PHA-based nanoparticles, such as emulsion solvent diffusion, nanoprecipitation, and dialysis are discussed. The characterization techniques such as UV-Vis, FTIR, SEM, Zeta Potential, and XRD are also elaborated.

Background: Super-paramagnetic iron oxide nanoparticles (SPIONs) are widely used metal nanoparticles for various applications for its magnetic property and biocompatibility. In recent years, pollution of our environment especially with heavy metals in waterbodies has become a major threat and has left us very minimal sources of freshwater to drink. SPIONs or surface modified SPIONs can be used to remove these heavy metals Methods: SPIONs were synthesized by co-precipitation method and further coated with a biopolymer, chitosan. Chromium solution was treated with the synthesized SPIONs to study the efficiency of chromium removal by surface adsorption. Later, the adsorption was analysed by direct and indirect analysis methods using UV-VIS spectrophotometry and isotherm studies. Results: Stable chitosan-coated SPIONs were synthesized and they adsorbed chromium better than the uncoated SPIONs, where it was adsorbing up to 100 ppm. Adsorption was found to be increasing with decrease in pH. Conclusion: The surface-modified SPIONs expressed cumulative adsorption action. Even after the adsorption studies, chitosan-coated SPIONs were possessing magnetic property. Thus, the surface-modified SPIONs can become an ideal nanotechnology tool to remove the chromium from groundwater.