Nanomaterials, classified as emerging pollutants that are toxic to the environment, are known to bioaccumulate across different trophic levels in the aquatic ecosystem. This study therefore investigates the distribution of silver and silver nanoparticles (AgNPs) in the aquatic environment of Skudai River, Johor, Malaysia. Water, sediment, plant, and fish samples were collected seasonally along four sites along Skudai River between May 2018 and April 2019. All samples were subjected to Ag analysis using an inductively coupled plasma mass spectrometer (ICP-MS). The analysis demonstrated that the concentration of Ag detected in water samples ranging from 0.001 to 0.505 mg/L was the lowest, whereas in the plants, 0.235 to 4.713 mg/kg of Ag was quantified. The upper sediments contained 0.036 to 28.115 mg/kg of Ag, whilst fish samples presented the highest accumulation of Ag, averaging between 9.144 and 53.784 mg/kg of Ag. Subsequently, the formation of silver nanoparticles was further proven by TEM-EDX analysis, where the detected size of AgNPs ranged from 20 nm to 35 nm. The overriding conclusion implied by bioaccumulation factor (BAF) and biota–sediment accumulation factor (BSAF) calculations suggested that Skudai River was indeed polluted by Ag and AgNPs. The values obtained stipulated that silver accumulation is occurring at an alarming rate and could therefore endanger fish consumers.

This study investigates the interactions between chromium (Cr) and microplastic under controlled laboratory conditions using low density polyethylene microbeads as plastic particles. Chromium was added to suspensions of in artificial seawater to investigate heavy metal adsorption on microbeads surface. Polyethylene microbeads proved to have affinity in providing surface area for chromium. It served as an effective sorption surface thus lowering amounts of chromium in seawater through adsorption process. The best percentage of heavy metals adsorbed to microbeads and adsorption capacity was 1.7 µg/g and 8.5 % at 1.0 µg/mL respectively. The maximum adsorption was monitored for 180 hours. Kinetic study was performed and fitted well in pseudo-first-order kinetic. In term of isotherm, dataset was in good agreement with both Langmuir and Freundlich with correlation at 0.977 and 0.9606 respectively. Adsorption of chromium to polyethylene microbeads had important implications for the potential role of microplastics, in this case microbeadschromium contaminated act as a quantified link in aquatic food webs.

All pharmaceuticals are separated chromatographically using the liquid chromatography-time of flight/mass spectrometry (LC-ToF/MS) on a 5 µm, 2.1 mm × 250 mm, C18 column at 0.3 mL/min. The recovery is investigated at two spiking levels, 10 and 1 ng/mL; the mean recovery is higher than 77, 84, and 93% in sewage treatment plants (STP) influent, STP effluent, and surface water, respectively. The limit of quantification (LOQ) averages 29, 16, 7, and 2 ng/L in STP influent, STP effluent, surface water, and drinking water, respectively. The matrix effect is also evaluated in STP influent and effluent. It is observed that sulfamethoxazole, prednisolone, ketoprofen, and glibenclamide are highly impacted compared to other compounds, −99, −110, 77, and 91%, respectively. The results show that six out of nine pharmaceuticals, namely atenolol, acetaminophen, theophylline, caffeine, metoprolol, and sulfamethoxazole are detected in STP influent, STP effluent, and surface water. However, the means of concentration are 561, 3305, 1805, 3900, 78, and 308 ng/L for atenolol, acetaminophen, theophylline, caffeine, metoprolol, and sulfamethoxazole, respectively, in STP influent. Caffeine and acetaminophen are detected with the highest concentration, reaching up to 8700 and 4919 ng/L, respectively, in STP influent.