Refine search
Results 1-5 of 5
Removal of Pollutants in Wastewater using Plastic-Based Media Biofiltration: A Meta-Analysis
2023
Muliyadi, Muliyadi | Purwanto, Purwanto | Sumiyati, Sri | Soeprobowati, Tri
The use of plastics as a biofilter medium is an environment-friendly and effective technology for reducing pollutants in liquid waste. The main objective is to analyze the ability of biofilters with plastic media to remove pollutants in wastewater by looking at several parameters. Various types of data were developed and analyzed to answer specific goals set through the search engines EBSCO, Scopus, and ProQuest by examining several parameters, including wastewater source, research scale, research period, temperature, media type, media thickness, and pollutant removal. The obtained data were processed to determine the distribution of the descriptions. Data related to biofiltration using plastic media was obtained from 152 articles, with only 14 articles in the search category. These findings show that all types of plastic media are effective for biofilm attachment and bacterial growth, resulting in a very large removal of pollutants present in liquid waste. Biofilters with plastic media are also known to be able to remove contaminants such as Chemical Oxygen Demand, biological oxygen demand, total organic carbon, nitrogen, phosphorus, ammonia nitrogen, hydrogen sulfide, toluene, ammonia, diethanolami, phenol, total suspended solids, and Escherichia coli. Synthetic wastewater (35.71%) was the most common wastewater source. Research related to biofiltration using plastic as the medium is mostly carried out on a laboratory scale with a total of 64.30% and using units of the day as an indicator of changes in a total of 71.42%, with an average experimental temperature of 29.1 °C.
Show more [+] Less [-]Recycling Polyethylene Terephthalate for use in Structural Concrete with Natural River Aggregates
2023
Huaquisto-Caceres, Samuel | Quenta-Flores, Darwin | Flores-Quispe, Eduardo Luis
Polyethylene terephthalate (PET) is one of the most common types of plastic waste found in municipal waste and has a negative impact on the environment, recycling and its use in concrete is an alternative solution to address these problems. The objective of the study was to evaluate the physical-mechanical behavior of hydraulic concrete with additions of PET plastic bottle fibers and natural river aggregates. The concrete was evaluated in its fresh state by means of the Slump and in its hardened state by means of density and compressive and flexural strengths, for which cylindrical and prismatic specimens were prepared with PET fibers at proportions of 2%, 4%, 6% and 8% by weight of cement plus the standard concrete designed for 21 MPa. It was found that the slump and density of the concrete decreased with additions of PET fibers. The 28-day compressive and flexural strengths increased to optimum values of 22.79 MPa and 3.19 MPa at 2% and 6% PET fibers, respectively. It is concluded that the viable application of 2 mm by 30 mm PET fibers in concrete is at 4% with dosages of 15.78 kg/m3 added to the standard concrete for structural elements subjected to compression and flexure with sustainable production at low cost.
Show more [+] Less [-]Sources of marine debris for Seychelles and other remote islands in the western Indian Ocean
2023
Vogt-vincent, Noam S. | Burt, April J. | Kaplan, David | Mitarai, Satoshi | Turnbull, Lindsay A. | Johnson, Helen L.
Vast quantities of debris are beaching at remote islands in the western Indian Ocean. We carry out marine dispersal simulations incorporating currents, waves, winds, beaching, and sinking, for both terrestrial and marine sources of debris, to predict where this debris comes from. Our results show that most terrestrial debris beaching at these remote western Indian Ocean islands drifts from Indonesia, India, and Sri Lanka. Debris associated with fisheries and shipping also poses a major risk. Debris accumulation at Seychelles is likely seasonal, peaking during February–April. This pattern is driven by monsoonal winds and may be amplified during positive Indian Ocean Dipole and El-Niño events. Our results underline the vulnerability of small island states to marine plastic pollution, and are a crucial step towards improved management of the issue. The trajectories used in this study are available for download, and our analyses can be rerun under different parameter choices.
Show more [+] Less [-]Drones for litter monitoring on coasts and rivers : suitable flight altitude and image resolution
2023
Andriolo, Umberto | Topouzelis, Konstantinos | van Emmerik, Tim H.M. | Papakonstantinou, Apostolos | Monteiro, João Gama | Isobe, Atsuhiko | Hidaka, Mitsuko | Kako, Shinichiro | Kataoka, Tomoya | Gonçalves, Gil
Multirotor drones can be efficiently used to monitor macro-litter in coastal and riverine environments. Litter on beaches, dunes and riverbanks, along with floating litter on coastal and river waters, can be spotted and mapped from aerial drone images. Items detection and classification are prone to image resolution, which is expressed in terms of Ground Sampling Distance (GSD). The GSD is determined by drone flight altitude and camera properties. This paper investigates what is a suitable GSD value for litter survey. Drone flight altitude and camera setup should be chosen to obtain a GSD between 0.5 cm/px and 1.25 cm/px. Within this range, the lowest GSD allows litter categorization and classification, whereas the highest value should be adopted for a coarser litter census. In the vision of drawing up a global protocol for drone-based litter surveys, this work sets the ground for homogenizing data collection and litter assessments.
Show more [+] Less [-]Drones for litter monitoring on coasts and rivers : suitable flight altitude and image resolution
2023
Andriolo, Umberto | Topouzelis, Konstantinos | van Emmerik, Tim H.M. | Papakonstantinou, Apostolos | Monteiro, João Gama | Isobe, Atsuhiko | Hidaka, Mitsuko | Kako, Shinichiro | Kataoka, Tomoya | Gonçalves, Gil
Multirotor drones can be efficiently used to monitor macro-litter in coastal and riverine environments. Litter on beaches, dunes and riverbanks, along with floating litter on coastal and river waters, can be spotted and mapped from aerial drone images. Items detection and classification are prone to image resolution, which is expressed in terms of Ground Sampling Distance (GSD). The GSD is determined by drone flight altitude and camera properties. This paper investigates what is a suitable GSD value for litter survey. Drone flight altitude and camera setup should be chosen to obtain a GSD between 0.5 cm/px and 1.25 cm/px. Within this range, the lowest GSD allows litter categorization and classification, whereas the highest value should be adopted for a coarser litter census. In the vision of drawing up a global protocol for drone-based litter surveys, this work sets the ground for homogenizing data collection and litter assessments.
Show more [+] Less [-]