The Baram River is one of the largest rivers in Sarawak, where many large industries, such as plywood, sawmills, shipyards, interisland ports, and other wood-based industries are located along the river. Microplastic contamination has become a widespread and growing concern worldwide because of the small sizes of microplastics and their presence in seafood such as fish, squid, scallop, crabs, shrimp, and mussels. In this study, microplastics were found in all sampling stations. Out of the 4017 microplastics found in the water and sediment, microplastics fragment accounted for 67.8% of total microplastics, followed by fiber, film, pellet, and foam. Five microplastic polymer types were detected by ATR-FTIR, including polyethylene (PE), polyester (PET) fibers, silicon polymer, nitrile, and polystyrene (PS). The most common microplastics size range in Baram River was 0.3-1 mm, with blue as the highly abundant color.
This study aimed to address the pressing issue of plastic pollution in aquatic ecosystems by assessing the prevalence and distribution of microplastics (MPs) in water and riverbank sediments of the Pekalongan River, a vital water source in Indonesia. From the present findings, MP concentrations in water ranged from 45.2 to 99.1 particles/L, while sediment concentrations ranged from 0.77 to 1.01 particles/g. This study revealed that fragment and film MPs constituted 30.1 % and 25.4 % of the total, respectively, with MPs measuring <1 mm and constituting 51.4 % of the total. Colored MPs, particularly blue and black MPs, accounted for 34 % of the total. The primary polymer components, as determined via Fourier transform infrared spectroscopy, were identified as polystyrene, polyester, and polyamide. In response to the escalating plastic waste crisis caused by single-use plastics, Pekalongan's local government implemented refuse segregation and recycling programs as part of its efforts to transition toward zero-waste practices.
The current study attempts to evaluate the formation, morphology, and physico-chemical properties of zinc oxide nanoparticles (ZnO NPs) synthesized from Clinopodium vulgare extract at different pH values and to investigate their antimicrobial and biomedical application potential. The reduction of zinc ions to ZnO NPs was determined by UV spectra, which revealed absorption peaks at 390 nm at pH 5 and 348 nm at pH 9, respectively. The spherical morphology of the nanoparticles was observed using scanning electron microscopy (SEM), and the size was 47 nm for pH 5 and 45 nm for pH 9. Fourier-transformed infrared spectroscopy (FTIR) was used to reveal the presence of functional groups on the surface of nanoparticles. The antibacterial activity was examined against Staphylococcus aureus, Streptococcus pyogenes, and Klebsiella pneumonia via the agar-well diffusion method. Comparatively, the highest activities were recorded at pH 9 against all bacterial strains, and among these, biogenic ZnO NPs displayed the maximum inhibition zone (i.e., 20.88 ± 0.79 mm) against S. aureus. ZnO NPs prepared at pH 9 exhibited the highest antifungal activity of 80% at 25 mg/mL and antileishmanial activity of 82% at 400 mg/mL. Altogether, ZnO NPs synthesized at pH 9 show promising antimicrobial potential and could be used for biomedical applications.
The main aim of this study was to assess the presence of microplastics in the water and sediments of the Surakarta city river basin in Indonesia. In order to accurately reflect the river basin, a deliberate selection process was employed to choose three separate sampling locations and twelve sampling points. The results of the study revealed that fragments and fibers were the primary types of microplastics seen in both water and sediment samples. Furthermore, a considerable percentage of microplastics, comprising 53.8 % of the total, had dimensions below 1 mm. Moreover, the prevailing hues identified in the water samples were blue and black, comprising 45.1 % of the overall composition. In contrast, same color categories accounted for 23.3 % of the microplastics found in the soil samples. The analysis of microplastic polymers was carried out utilizing ATR-FTIR spectroscopy, which yielded the identification of various types including polystyrene, silicone polymer, polyester, and polyamide.