Given the increase in plastic production, persistence, and toxicity in the environment, understanding the probability of microplastics (MPs) accumulation in the sediments of the rivers' estuary is urgently needed. In this study, sediments of the estuary of 17 rivers, ending to the Caspian Sea, were evaluated at two depths (0–5 cm and 5–15 cm). Plastic particles were categorized into two groups in terms of size: small MPs and large MPs. The combination of observational techniques, FTIR, and SEM analysis was applied to identify MPs. The mean of MPs in 17 rivers was obtained at a depth of 0 to 15 cm of sediments 350.6 ± 232.6 MP/kg. The fiber was identified as the predominant particles in sediments, and foam-shaped particles were the least amount in the sediment. In terms of polymer structure, polyethylene (PE) (20%) and polyvinyl chloride (PVC) (2%) showed the highest and lowest prevalence, respectively. In the current study, the number of MPs was higher than the average of MPs in sediments of recreational-tourist areas and non-tourist areas of the southern Caspian coast. Results from this study indicate that sediments of the rivers' estuary are a hotspot of plastic particle pollution. Therefore, plastic management in the path of the Caspian catchment area of Iran, and cleaning rivers coast and rivers mouth from plastic is recommended.

PURPOSE OF REVIEW: This review presents an overview of high-performance ultrafiltration (UF) membranes, including fouling resistant, micellar-enhanced, tight, adsorptive, and catalytic UF. The review discusses recent advances in the development of these membranes, focusing on their preparation method, performances, and applications. Then, the review concludes with a discussion of the challenges and future outlooks of these UF membranes in wastewater treatment. RECENT FINDINGS: Recently, the development of UF membranes has resulted in membranes with high performances in wastewater treatment. For instance, fouling-resistant membranes synthesized through surface modification show significant improvement in terms of fouling reduction and flux recovery. In addition, coupling with complexation reaction, tightening membrane pore structure, endowing membrane with adsorption ability, and functionalizing UF membrane with catalytic properties, greatly improve the performance of UF in removing pollutants. Highly selective UF membranes can achieve remarkable various pollutant removals (e.g., organic compounds and heavy metals) from wastewater. UF membrane has been widely applied in wastewater treatment due to its low-pressure operation, relatively low energy consumption, high product quality, and simple operation. Significant efforts have been dedicated to improve UF membrane performance. Fouling resistant and highly selective UF membranes have been developed successfully, which showed remarkable performance in various pollutant removals. These high-performance UF membranes provide the possibility of process simplification in wastewater treatment since they can remove a more wide range of pollutant types, and thus post-treatment step may be reduced.

Cigarette butts are considered the most common form of personal litter around the world. It is estimated that 5.5 trillion cigarettes are consumed globally each year and that 4.95 trillion are discarded in some natural or anthropic environment around the world. This study evaluated the pollution of urban beaches in the Brazilian Northeast by cigarette butts in relation to other types of litter. Samplings were conducted in a month of high season (January 2016), at eight heavily used beaches. In the place with the highest concentration of users in each beach, a 200 m transect (3 m width) was established parallel to the water on the most recent strandline. All items >1 cm were counted and classified into categories according to composition (plastic, cigarette butts, wood, glass, metal, paper and organic, such as food leftovers and coconuts) using a standard worksheet. Cigarette butts were considered as an isolated category of litter. A total of 10,880 items was registered. The most abundant items were plastics (44.96%) and cigarette butts (38.36%). Among plastics, the most abundant items were straws, metallic food packaging, sticks (lollipop and popsicle) and cups. Plastic fragments were also abundant in all beaches evaluated, corresponding to 14.5% of the total plastics.

This study assessed the concentrations, sources, and risks of polycyclic aromatic hydrocarbons (PAHs) in sediments from the Rivers Niger, Ase and Forcados in the western Niger Delta. The concentrations of PAHs (in μg kg⁻¹ dry weight), as determined by gas chromatography–mass spectrometry, in sediments from these rivers varied from 2400 to 19,000, 2930 to 16,100, and from 1620 to 19,800 for the Niger, Ase and Forcados Rivers respectively. High molecular weight (HMW) PAHs were the most prevalent compounds present in these sediments. An assessment of the possible ecological and human health risks suggested high risks for both organisms and humans. The PAH source analysis suggested that sediments from these river systems were contaminated with PAHs arising from burning of biomass, gasoline/diesel emissions, burning of natural gas, and oil spillages.

To understand how the marine copepod Tigriopus japonicus responds to the toxic marine dinoflagellate Gymnodinium catenatum, we assessed acute toxicity and investigated swimming behavior parameters (e.g., swimming speed, swimming path trajectory, and swimming distance) in response to G. catenatum exposure. In addition, the mRNA expression levels of detoxification-related genes (e.g., phase I cytochrome P450 [CYP] and phase II glutathione-S transferase [GST]) were measured in G. catenatum-exposed copepods. No significant change in survival was observed in response to G. catenatum, but swimming speed was significantly decreased (P < 0.05) at a high concentration of G. catenatum (600 cells/mL). Furthermore, the swimming distance was significantly decreased (P < 0.05) compared to that of the control at 600 cells/mL G. catenatum, while no significant change in swimming path trajectory was observed, suggesting that G. catenatum potentially has adverse effects on the swimming behavior of T. japonicus. In addition, the transcriptional regulation of T. japonicus CYPs and -GSTs were significantly upregulated and downregulated (P < 0.05), respectively, in response to G. catenatum. In particular, certain genes (e.g., CYPs [CYP307E1, CYP3041A1, and CYP3024A2] and GSTs [GST-kappa, GST-mu5, and GST-omega]) were significantly induced (P < 0.05) by G. catenatum, suggesting that these genes likely play a critical role in detoxification mechanisms and might be useful as potential molecular biomarkers in response to G. catenatum exposure. Overall, these results elucidate the potential impacts of the dinoflagellate G. catenatum on the swimming behavior and detoxification system of the marine copepod T. japonicus.

An investigation of microplastic abundance and its characteristics was conducted in Muara Angke Wildlife Reserve, a relic mangrove forest in the Jakarta metropolitan, to contribute to marine microplastics' national data inventory. Microplastics were found in all the stations, with an average of 28.09 ± 10.28 particles per kg of dry sediment (n kg⁻¹). Sediments in the outside mangrove area contained more microplastics than the inside area. Foam form was the most dominant in all the samples and was found more abundant on the outside. More than half of microplastics were of size <1000 μm, and nearly 50% were polystyrenes. This polymer is widely used for food packaging, which is prone to be fragmented. Polypropylene and polyethylene form another 50% of microplastics, which are widely used for textiles and fishing gears. As Jakarta is the largest city in Indonesia, this microplastic dataset may be the benchmark for other mangroves around the country.

In-situ burning (ISB) has been an oil combat technique studied since the 1950s. However, burning of the oil on the sea surface along the coastline, coastline ISB (cISB), is novel and was tested for the first time in the Arctic along a rocky coast in the summer 2017. A light crude oil was burned and effects of the cISB operation on the littoral zone communities investigated. The impact on macroalgal vegetation and associated fauna was analysed in three littoral zone levels. The analyses revealed limited effects on the littoral community, and that variation between sample plots and years in macroalgal biomass and coverage, as well as fauna biomass and abundance was higher than the impact from cISB. Therefore, it is concluded that cISB in the Arctic along a rocky shore may be an oil spill response option with relatively low environmental side effects for the specific oil type used.

PURPOSE OF REVIEW: Microbial interaction determines the performance, stability, and resilience of the microbial communities. Understanding microbial interactions benefits the development of environmental biotechnology. The purpose of this review is to summarize the recent findings of microbial interactions in pollution control ecosystems from aspects of the substrate degradation, energy utilization, electron transfer, and information exchange. RECENT FINDINGS: Cross-feeding of substrates such as vitamins was found to be necessary for the degradation of some trace organic contaminants. Under different conditions, microorganisms can mediate various energy-utilization pathways (e.g., co-metabolism) to grow. Electroactive bacteria and cable bacteria can mediate extracellular electron transfer via conductive pili, c-type cytochrome, or filamentous structure. Quorum sensing plays an important role in the microbial aggregation and functional microbe enrichments. With all these knowledges, it will potentially benefit the development of disruptive environmental biotechnologies. This review summarized recent findings of microbial interactions, many of which have huge potentials to advance environmental biotechnologies. Multi-omics methods should be further applied for comprehensively confirming known and unknown microbial processes. The co-occurrence network should be applied to unravel the interlinks among substrate degradation, energy utilization, electron transfer, and information exchange. The proper regulation of microbial interactions in practical application should be further addressed.

Plastic debris in the coastal environment is subject to complex and poorly characterized weathering processes. To better understand how key environmental factors affect plastic degradation in a coastal zone, we conducted an in situ experiment. We deployed strips of high density polyethylene (HDPE) and polystyrene (PS) in paired coastal areas of contrasting conditions (hydrodynamic activity: erosional or depositional; water depths: subtidal or intertidal). Strips were collected after environmental exposures at 4, 8, and 43 weeks and analyzed for change in mass, algal biofilm growth, and imaged by petrographic and electron microscopy (SEM-EDS). Significant surface erosion was evident on both polymers, and was more rapid and more extensive with PS. Degradation of PS was responsive to intensity of hydrodynamic activity, and was greater at intertidal depths, highlighting the critical role played by photo-oxidation in the coastal zone, and suggesting that algal biofilms may slow degradation by playing a photo-protective role.

This baseline intends to report on littering related to single-use plastic straws, contextualized on two touristic beaches on the Northern shores of Crete (Greece). While beached straws were found to be mainly depending on local drivers, the study further highlighted an additional source of pollution related to plastic straws: the clear wrap in which single-use items can be offered to users. Over the summer months, a number of discarded straw wraps was in fact found, significantly related to both beach width and the presence of colorful straws. Wraps are different in shape, material, as well as likelihood of being dispersed and broken down in the environment, and easily escape estimates from non-targeted sampling. The ban on single use items seems then to be the most effective approach to avoid straws and, indirectly, straw wraps litter or spills.