The extensive use of personal protective equipment (PPE) driven by the COVID-19 pandemic has become an important contributor to marine plastic pollution. However, there are very few studies quantifying and characterizing this type of pollution in coastal areas. In the present study, we monitored the occurrence of PPE (face masks, bouffant caps, and gloves) discarded in 13 sites along Cox's Bazar beach, the longest naturally occurring beach in the world. The vast majority of the items were face masks (97.9%), and the mean PPE density across sites was 6.29 × 10⁻³ PPE m⁻². The presence of illegal dumping sites was the main source of PPE, which was mainly located on touristic/recreational beaches. Fishing activity contributed to PPE pollution at a lower level. Poor solid waste management practices in Cox's Bazar demonstrated to be a major driver of PPE pollution. The potential solutions and sustainable alternatives were discussed.

Plastic food packaging and containers (n = 263) have been retrieved from the scarped foredunes at Perran Beach, SW England, following a storm surge. Samples displayed evidence of cracking, scratching, discolouration, staining and hydroxyl and carbonyl stretching, but legible text indicating their origin, dates of manufacture/expiration, packaging codes and logos, coupled with online product searches, allowed 25 food packets and 87 containers to be aged. Estimates of food packaging age spanned a 43-year period (1975–2018), with a median age of 25 years, while estimates for containers spanned 57 years (1962–2019), with a median age of 19 years. Plastic derived from local littering and offshore sources appears to be trapped within the foredunes for years to decades and subsequently released as “fresh” beach litter following surges sufficient to effect scarping. Dunal systems may act as significant reservoirs of historical plastics and play a critical role in their recycling and retention in the coastal zone.

PURPOSE OF REVIEW : Improper discharge of industrial effluents would lead to direct contamination of our water, air, and soil systems. Without proper treatment, both these inorganic and organic-matter-containing waste would pose harmful effects towards aquatic organisms, overall water quality, reduction in soil health, and increase in greenhouse gasses from anaerobic microbial degradation activities. RECENT FINDINGS : Current treatment technologies involve the use of combined chemical, biological, and physical approaches, which has been proven very effective. Another useful alternative is to utilize the high organic content present in the waste as substrate for the metabolism of microbes as catalyst in industrial processes including water treatment as well as production of useful microbial secondary metabolites such as pigments. This review highlights some example for the microbial biotransformation and biomineralization of organic-rich industrial discharges. This is important based on its potential to be applied as useful alternative techniques to dispose huge volumes of industrial waste as well as reducing high cost of sustaining biological-based industrial processes that would require substantial investment notably for the microbial growth medium. Nevertheless, clear insight into the engineering aspects of such processes and sufficient knowledge on its feasibility to function properly at pilot-scale level are of paramount importance prior to any commercialization attempts.

This paper aims to compare two foraminiferal based biotic indices generally used to evaluate the ecological quality status (EcoQS): the Foram-AMBI and the Foram Stress Index (FSI). For this purpose, we report the distribution and diversity of living foraminiferal assemblages and the environmental variables from a bathymetric transect in the Southern Adriatic Sea. The two indices agree well with the detected organic enrichment but indicate conflicting EcoQS as the Foram-AMBI detects good environmental conditions, whereas the FSI describes a poor-moderate quality. Many species not assigned (including soft-shelled foraminifera) are to blame for the different results. Also, both foraminiferal-based indices neglect the heavy metal increase encountered in the deepest stations. These findings suggest the need for a more in-depth analysis to improve the ecological status evaluation of marine benthic systems, including other descriptors as chemical pollutants in combination with biotic indices sensitive to organic matter enrichment.

The sediments inside the ballast tanks might compromise the effectiveness of the ballast water exchange procedure. In the present study, the sediment removal from double bottom ballast tanks due to flow-through ballast water exchange is investigated by simplified experimental and numerical models. Two flow rates and two sediment densities were considered to verify their influence on the process. Besides, the effectiveness of two tank configuration modifications to improve the sediments removal was investigated. The first is the introduction of a flow deflector inside the tank and the second is the water inflow from the bottom. A fully Lagrangian particle-based method is adopted to simulate the sediment removal process with complex tank geometry. A new boundary condition is proposed to model the mesh of the bottom inlet in the bottom inflow configuration. Despite the simplifications of the numerical model, the computational results are in good agreement with the experimental ones. The results show that the flow-through ballast water exchange method might not be effective to remove the sediments entrapped between the bottom stiffeners, and the proposed modifications, despite challenging implementation, improve the sediment removal.

After the largest mining tailings spill in Brazil, the Rio Doce estuarine ecosystem was severely impacted by metal contamination. In a 28-day laboratory experiment, we examined the effects of the polychaeta Laeonereis sp. on fluxes of oxygen and metal across the sediment-water interface. The density-dependent effect of Laeonereis sp. in the oxygen and metal fluxes was tested at low and high (74 and 222 ind m⁻², respectively) densities, and compared with defaunated controls. The higher worm density had an amplified effect on the oxygen flux, sediment uptake of Al and Mn, and Fe oxidation compared with the control, but no significant effects on other metals (Ba, Cd, Co, Cr, Cu, Ni, and Zn). Higher worm density increased the oxidation of Fe phases, but no effect in the solid phase of other metals. Consequently, Laeonereis sp. bioturbation prevents the reduction of Fe phases and the release of metal-bound-contaminants to estuarine systems.

Studding the behaviour and danger of nanoparticles (NPs, minerals and amorphous phases) in the estuarine ecosystem is presently incomplete by the lack of measureable description of NPs in the ecological conditions, such as suspended-sediments (SS). In the last years, several works have revealed the toxic consequences of ultra-fine and nanoparticulate compounds on diverse systems, raising apprehensions over the nanocontaminants behaviour and destiny in the numerous ecological partitions. The general objective of the manuscript is to explain the geochemical conditions of the LES (Laguna estuarine system, southern Brazil) suspended sediments covering an area around the main South American coal plant, enhancing the creation of future public policies for environmental recovery projects. Subsequently the discharge of nanoparticles and toxic element (TE) in the ecosystem, NPs react with several constituents of the nature and suffers active alteration progressions. Contamination coming from engineering actions, wastewater, are something identifiable, however when these contaminations are accompanied by other contamination sources (e.g. mining and farming) the work gets defaulted. By combining material about the concentration of TE contaminants and NPs occurrences, this work offers novel visions into contaminant contact and the possible effects of such exposure on estuarine systems in Brazil. The results presented here will be useful for different areas of estuaries around the world.

Ship ballast water can transfer harmful organisms, including antibiotic-resistant bacteria (ARB), among geographically isolated waters. In this study, the presence and composition of ARB and multiple ARB (MARB) were investigated in the ballast waters of 30 vessels sailing to the Port of Jiangyin (Jiangsu Province, China). ARB were detected in 83.3% of the ship's ballast water samples. Moreover, penicillin- and cephalothin-resistant bacteria were the most and least prevalent ARB in the ballast waters, respectively. Oxytetracycline-, chloramphenicol-, tetracycline-, and vancomycin-resistant bacteria were also detected at high concentrations. The multiple antibiotic resistance index demonstrated the presence of MARB, which exceeded 200% in the ballast waters of five ships. Furthermore, 15 species, including the human opportunistic pathogens Vibrio alginolyticus and Serratia nematodiphila, were resistant to at least three antibiotics. Therefore, the potential ecological risk of ARB warrants further attention because of their effective invasion by ballast water.

PURPOSE OF REVIEW: With economic development and population increase, environmental pollution and water shortages have become inevitable global problems. Microalgae-based wastewater treatment technology can not only purify wastewater and solve environmental pollution problems but also use the nutrient elements in wastewater to produce algal biomass, which has attracted more and more attention. This work reviews the current status of microalgae bioremediation of wastewater, aiming to provide a reference for further research in this field. RECENT FINDINGS: Microalgae have been proven to be used to treat municipal wastewater, agricultural wastewater, and industrial wastewater and can convert nutrients into biomass. In order to further improve the wastewater treatment efficacy and algal biomass productivity, it is necessary to understand the mechanism of microalgae to remove nutrients and pollutants from wastewater. Currently, open ponds and enclosed photobioreactors are used for large-scale cultivation of microalgae, and various harvesting technologies are developed to achieve low-cost capture of microalgae as much as possible. Microalgae are rich in pigments, proteins, lipids, carbohydrates, vitamins, and antioxidants and can produce a variety of value-added products, making this biotechnology more cost-effective. This review discusses the purification efficiencies of microalgae on wastewater from different sources and introduces the mechanism and influencing factors by which microalgae remove carbon, nitrogen, phosphorus, heavy metals, and antibiotics in details. Moreover, the advantages and disadvantages of different microalgae cultivation systems are analyzed. Finally, the different harvesting methods and the current application of microalgae biomass in various fields are summarized.