This study presents data on abundance and density of macro-floating marine debris (FMD), including their composition, spatial distribution and potential sources off continental Portugal. FMD were assessed by shipboard visual surveys covering ±252,833km2 until the 220nm limit. The FMD average density was 2.98items/km2 and abundance amounted to 752,740 items. Unidentified plastics constitute the major bulk of FMD (density=0.46items/km2; abundance=117,390 items), followed by styrofoam, derelict or lost materials from fisheries, paper/cardboard and wood material. The North sector of the area presents higher FMD diversity and abundances, probably as a result of the high number of navigation corridors and fisheries operating in that sector. Most FMD originate from local sources, namely discharges from vessels and derelict material from fisheries. Considering the identifiable items, cables and fishing lines were the only fishing related items among the top ten FMD items in Portuguese offshore waters.

Peru has a large small-scale fishing fleet upon which many coastal communities depend for their food and livelihoods. Nonetheless, no thorough assessments have been conducted of solid waste production and management of small-scale fisheries (SSF) and associated communities. We aimed to assess gillnet SSF and household solid waste generation in San Jose, north Peru. A solid waste generation assessment was conducted by monitoring solid waste production during 22 fishing trips and interviewing 70 families. Daily waste generation and recycling per capita, were calculated applying separate Generalized Linear Mixed-Effect Models. Organic waste is the most frequently produced during fishing activities (38%) and at home (83%), followed by plastic and metal. Glass, paper/cardboard, and fishing nets were solely produced during fishing trips. Daily waste per capita was estimated on 0.14 kg∗(day)⁻¹ onboard, and 0.33 kg∗(day)⁻¹ at home. Additionally, perception interviews showed that the population of San Jose perceived solid waste as a threat to public health and marine ecosystems. This study provides a first attempt to assess solid waste production in a Peruvian fishing community, showing the need for an integrated management plan embracing vessel and land-based solid waste generation.

Morocco is well known for its attractive Mediterranean beaches, which play an important economic role. With the fast development and growth, these beaches have become more contaminated by marine debris. This paper examined the abundance, composition and marine debris sources on five beaches in the Moroccan Mediterranean during 2019 four seasons. A total of 7839 marine debris were collected from the five beaches with a total weight of 231 kg. The average density of the debris collected was 0.20 ± 0.098 items/m². Polymer materials constituted the majority of debris found, with a percentage of 71.36%, followed by paper/cardboard (11.50%), metal (5.77%), processed wood (5.34%), cloth/textile (2.51%) and glass/ceramics (1.76%). Human recreational activities were the main source of debris (70.13%), followed by smoking-related (13.98%). Debris density appears to be particularly influenced by beach users. Awareness campaigns are needed for beach users to improve the quality of the beaches.

In the Antarctic Peninsula, most important activities are touristic visits, from the second half of the 20th Century, and scientific investigation linked to 75 research stations. Beach litter content/abundance was investigated at 17 beaches in Admiralty Bay (King George Island, Antarctica) and the type of plastic material was determined by Raman spectroscopy. An average value of 0.16 items m⁻¹ was observed. Wood items consisted of processed wood fragments representing 47.27% of the total. Foam represented 21%, hard plastic pieces 9.68% (consisting of polyvinyl chloride or high density polyethylene), metal 3.37%, rubber fragments 2.81%, foamed plastic pieces 2.66% (composed by polystyrene), the rest of categories representing less than 2% of the total. Wood debris and metal are essentially remnant objects of ancient whaling activities and research expeditions, polyurethane and expanded polystyrene materials have different origins and hard plastic, rubber, paper/cardboard and paint fragments seem mostly linked to present research activities.

This study is the first study to determine beach litter pollution in the Eastern Mediterranean region of Turkey. The pollution of beach litter were seasonally evaluated in a selected beach in the East Mediterranean Sea between August 2019 and April 2020. Beach litter survey was carried out seasonally according to ‘Guidance on Monitoring of Marine Litter in European Seas’ published by European Marine Strategy Framework Directive Technical Subgroup on Marine Litter. During the study, a total of 10.717 items and 229.29 kg were collected. The average litter abundance was 2.679 ± 0.418 items/m² and 57.326 ± 7.165 g/m². The results indicated that the most common type of litter were plastic and cloth/textile (84%) followed by paper/cardboard (56%), the unidentifiable (51%). Litter density showed significant seasonal differences with the highest in summer (P < 0.05). Akyatan beach was classified as extremely dirty according to Clean Coast Index. It was observed that the litter in the region averagely consisted mostly of mixed packaging litter (23.75%), domestic litter (20%) and unclassified litter (16.2%) items. Our results show that the coast of Akyatan Lagoon exposed to a significant amount of marine litter pollution originated from land-based sources. This study provides further evidence that there is a significant litter pollution in the East Mediterranean Sea and that the main component are plastics, which pose a great treat to Mediterranean Sea environment.

The amount and composition of beach litter was assessed, during spring 2018, at 56 sites along the coast of Alicante Province, on the western Mediterranean Sea. Selected sites covered “natural” (19), “village” (17) and “urban” (20) bathing areas and a total of 10,101 litter items was counted in an area of 201,686 m2. Plastic represented the dominant material with 8345 items, i.e. 82.6% of all debris; paper and cardboard numbered 566 items (i.e. 5.6%); pottery and ceramics 348 (3.4%); metal 325 (3.2%); cloth 231 (2.3%); glass 147 (1.5%); rubber 64 (0.6%); wood 46 (0.5%) and other materials summed 29 items, i.e. 0.3% of all debris. Cigarette butts, 45.6% of total items, were observed at different coastal sites: i.e. 1028 units at natural, 1148 at village and 2431 at urban sites. Despite the efforts of local administrations, which enforced cleaning operations at most sites, litter items were essentially related to beachgoers followed by wastewater discharges and fishing activities.

The current study investigated the efficiency of poly ferric chloride (PFC) and poly titanium tetrachloride (PTC) in coagulation-flocculation process for treatment of paper and cardboard wastewater. The effect of pH (5–11), coagulant concentrations (100–1000 mg/L), mixing rate (10–60 rpm), mixing time (5–25 min), and settling time (5–30 min) were examined. The results showed that the removal efficiency for turbidity, total suspended solids (TSS), and chemical oxygen demand (COD) by PFC and PTC coagulants increased with pH rising up to 9 for the former and 7 for the latter coagulant. Furthermore, the removal efficiency for the afore-mentioned parameters increased along with a 30 rpm increase in the mixing rate, while the mixing time reached 20 min. It was also found that the best removal efficiencies for turbidity, TSS, and COD by PFC under optimal conditions (pH 9, coagulant dose 800 mg/L, and settling time of 25 min) were 97.11%, 99.1%, and 84.91%, respectively. In addition, the removal efficiencies for PTC (optimal conditions of pH 7, coagulant dose 600 mg/L, and settling time of 15 min) were found to be 98.29%, 99.29%, and 86.42%, respectively. Water recovery and the produced sludge volume by PFC were 80% and 200 cm³, respectively, in the settling time of 25 min and for PTC were 81.5% and 185 cm³, respectively, in the settling time of 15 min. Costs of the coagulation-flocculation process for treatment 1 m³ of paper and cardboard wastewater using PTC and PFC were 0.42 $ and 0.32 $, respectively. Finally, it can be concluded that compared to PFC, PTC with higher settling rate has a greater efficiency for treatment of paper and cardboard wastewater.

End-of-life packaging materials (EOLPM) present an important challenge from an environmental and financial perspective at utility-scale solar energy (USSE) sites. Reuse on-site represents, in particular for remote sites, a significant contribution to sustainable business practice as it provides a higher value end use when used to develop on-site mulch to enable soil improvement, reducing transport emissions (from the least preferred option of off-site disposal to landfill), reducing costs, and employing local contractors. The objective of the study was to enable on-site reuse, which was primarily achieved through chemical and physicochemical characterization of EOLPM streams; cardboard, and wood. Given the common occurrence of these materials in the rapidly growing renewable energy sector, it represents an important scope of work for the sector internationally. The methods used for characterization of the EOLPM, the first of its type reported, included a range of organic and inorganic chemical analyses, phytotoxicity testing, followed by an environmental and high-level (or initial) financial benefit cost analysis. Key scientific findings were that only trace concentrations of chemicals of potential concern (COPC) were detected; the material was not phytotoxic and has potential for soil improvement at the site, and the selected option of on-site reuse (of the materials as a mulch) had a global warming potential of 50 times less than the business as usual option (transport to landfill). The results also demonstrated the broader potential for using EOLPMs from USSE sites for soil improvement at remote locations rather than transporting offsite for disposal or reuse. Structural changes will need to be made to the way in which markets operate to achieve circular economy outcomes for these EOLPMs.

When old corrugated cardboard (OCC) is returned to the paper mill for repulping and reuse, the starch, which is added to the paper surface as a reinforcement agent, is dissolved into the pulping wastewater. Most of the OCC pulping wastewater is recycled to save precious water resources; however, during the water recycling process, the accumulation of dissolved starch stimulates microbial reproduction, which causes poor water quality and putrid odor. This problem seriously affects the stability of the papermaking process and product quality. In this study, phosphomolybdic acid (H₃PMo₁₂O₄₀, abbreviated as PMo₁₂) was utilized to catalyze the waste starch present in papermaking wastewater to monosaccharides, realizing the resource utilization of waste starch. The results showed that the optimized yield of total reducing sugar (78.68 wt%) and glycolic acid (12.83 wt%) was achieved at 145 °C with 30 wt% PMo₁₂ at pH 2, which is equivalent to 91.51 wt% starch recovered from wastewater for resource utilization. In addition, the regeneration of the reduced PMo₁₂ was realized by applying a potential of 1 V for 2 h. Overall, this study has theoretical significance and potential application value for resource utilization of waste starch in OCC pulping process and cleaner management of OCC waste paper.

Three-dimensional carbon aerogel (CA800) was prepared from waste corrugated cardboard (WCC) by the procedure of slurrying, solvent replacement, drying, and carbonization in turn, and the product was explored as an all-in-one evaporator for solar steam generation without bulk water. Carbonization of the precursor was investigated using thermogravimetric analyzer coupled with Fourier transform infrared spectrometer. Results showed that CO₂, CO, furfural, and levoglucosan were released during pyrolysis of WCC within the range of 300 to 390 °C, while polymerization of newly formed char between 390 and 580 °C mainly resulted in the formation of CO₂ and CO. Both pyrolysis and polymerization reactions can be described by diffusion-controlled mechanisms, and the activation energies were 155.62 and 11.17 kJ mol⁻¹, respectively. CA800 possessed a BET surface area of 210 m² g⁻¹. Light can be effectively absorbed and converted into heat by CA800, and its surface temperature achieving 73 °C under 1 kW m⁻² irradiation. CA800 had outstanding wettability due to the presence of hydrophilic minerals in carbon matrix, and it was able to store as much as 15 times its own weight in water due to its abundant interconnected channels and hierarchical nanopores. Solar-driven water evaporation rate over CA800 achieved 1.72 kg m⁻² (normalized to projection area), which was nearly 6 times higher than the value achieved by the bare water system. The photothermal conversion efficiency was calculated to be 118 %, and the overestimated efficiency was caused by the environmental energy gained by the cold evaporation surface of CA800.