Plastics recycling is an important component of the circular economy. In mechanical recycling, the recovery of high-quality plastics for subsequent reprocessing requires plastic waste to be first sorted by type, color, and size. In chemical recycling, certain types of plastics should be removed first as they negatively affect the process. Such sortation of plastic objects at Materials Recovery Facilities (MRFs) relies increasingly on automated technology. Critical for any sorting is the proper identification of the plastic type. Spectroscopy is used to this end, increasingly augmented by machine learning (ML) and artificial intelligence (AI). Recent developments in the application of ML/AI in plastics recycling are highlighted here, and the state of the art in the identification and sortation of plastic is presented. Commercial equipment for sorting plastic recyclables is identified from a survey of publicly available information. Automated sorting equipment, ML/AI-based sorters, and robotic sorters currently available on the market are evaluated regarding their sensors, capability to sort certain types of plastics, primary application, throughput, and accuracy. This information reflects the rapid progress achieved in sorting plastics. However, the sortation of film, dark plastics, and plastics comprising multiple types of polymers remains challenging. Improvements and/or new solutions in the automated sorting of plastics are forthcoming.

Food waste is generated in large amounts locally and globally, and requires expenditure for disposal. However, it has high nutritional value and almost no toxic components. Therefore, it can be returned to mushroom mediums for further use, leading to food waste circulation. Though disposing of spent mushroom substrate (SMS) after harvesting is an additional problem, there have been increased efforts to compost it and apply it to the soil for growing vegetables. This study, therefore, aimed to optimize (1) mushroom spawn production with rice hull, (2) mushroom substrates using food waste to accelerate food waste recycling, and (3) the utilization of SMS as an organic fertilizer. An optimal substrate composition and high yield were obtained at 120–140 g of food waste per bag among substrates from Pleorutus ostreatus and Pleorutus citrinopileatus; therefore, using a high ratio of food waste in the mushroom mediums was achieved. On the other hand, the SMS of P. citrinopileatus demonstrated higher plant biomass growth, at 36 g, than that of P. ostreatus, at 21.2 g, in a treatment using SMS + okara. The present discovery is that people may be encouraged to be mindful of food loss by the delivery of mushrooms and plants grown from agro/food waste to the dining table, and this circular system may therefore be used as a key resource in mushroom and plant cultivation and to achieve a zero-emission cycle.

The major problems related to environmental pollution are increasingly present among us. The uncontrolled use and incorrect disposal of products means that these problems are increasing at frightening rates. In this context, a major related problem is the incorrect disposal of dishwasher sponges that are no longer useful; their material being made up of petroleum derivatives causes this problem to be leveraged in the environment. In the present work, we evaluated and carried out tests in which these dirty sponges that would be discarded were used for the purpose of developing new sustainable adsorbent materials. These materials were washed and dried, crushed and made available for use, by which they were kept in contact with a paracetamol solution, evaluating the effect of mass, pH, kinetics, equilibrium, thermodynamic parameters, and cost analyses. The results demonstrated an adsorptive capacity of approximately 40 mg g−1 and its cost was relatively viable, since this material would otherwise be discarded incorrectly. In conclusion, this material achieved the good removal of this studied contaminant and became an economical, viable, and ecologically viable material.

The United Nations Environment Programme’s (UNEP’s) Food Waste Index Report 2021 highlights a global annual food waste of 1 billion tons. The UNEP plays a crucial role in achieving Sustainable Development Goal (SDG) 12.3, which aims to halve per capita global food waste (FW) at the retail and consumer levels and reduce food losses along production and supply chains globally by 2030. On the other hand, the agricultural sector faces the challenge of increasing productivity to feed the world’s growing population while reducing the environmental impact on ecosystems and human health. In this context, the conversion of agri-food waste (AFW) into biocides, bio-based fertilizers (BBFs) and biostimulants could represent a successful approach to tackle all these issues. This review shows the latest findings on the different sources of AFW and the application of their bioactive compounds in agriculture. Increasing crop yields and improving plant physiology through the utilization of AFW-derived value products aligns with a circular economy approach, bolstering people’s confidence in managing food waste for improved food production.

SDG target 12.3 calls for halving food waste in retail, food service, and households by 2030. The food waste index developed for this purpose includes parts attached to food that are usually removed intentionally (“unavoidable food waste”) and counts conversion into animal feed and utilisation as biomaterial as a means of reduction. In Japan, the “Food Waste Recycling Law”, which has been in effect since 2001, promotes the recycling of food waste generated from businesses, designating feed conversion as a top priority. On the other hand, based on the more recent “Food Loss Reduction Promotion Act” of 2019, the government is currently promoting reduction in avoidable food waste to meet the SDG target. Based on statistical sources and interviews with ministry officers, this paper explains the history and achievements of Japan’s 23-year policy based on the Food Recycling Law, as well as the tension between the two legislations.

The usage of Reclaimed Asphalt Pavement (RAP) material is a highly resource-conservative, economical, and sustainable practice in flexible pavement construction. However, its usage in hot mix asphalt (HMA) is capped at 25% by the majority of state transportation agencies due to its aging levels, stiffness characteristics, and handling capabilities, which may result in early-age pavement distress. Though researchers suggest methodologies to increase RAP usage, higher RAP percentages in asphalt pavements require the support of state authorities. The main objective of this paper is to provide information on how different states design their mixtures with high RAP percentages. This study reviewed the current state of practice of fifty (50) state DOTs in the United States (US) with respect to RAP usage and the factors governing its regulations. It was observed that the limit of RAP content is mainly governed by traffic levels, gradation, binder content, and stiffness contributed by RAP and layer position in a pavement structure. The specifications also suggest that apart from volumetric and performance justification, blending charts, fractionation, and virgin binder grade selection would facilitate the use of higher RAP content in HMA. Controlled mixture design abiding by state specifications can increase the allowable RAP to 40–100%.

Using a trace polychlorinated-ρ-dibenzodioxins and dibenzofurans (PCDD/Fs) stabilizing generator, an experimental study related to the influence of temperature (150, 165, and 180 °C) and activated carbon (AC) dosage (0.10, 0.15, and 0.20 g) on the adsorption effect of gas-phase PCDD/Fs via coal-based AC was conducted. Increasing the AC dosage is the most efficient method to improve the PCDD/Fs adsorption efficiency from 65.8% (0.10 g) to 93.0% (0.20 g) at 150 °C in an exponential trend. Both the polychlorinated-ρ-dibenzodioxins (PCDD)/polychlorinated dibenzofurans (PCDF) ratio and the Cl-PCDD/Fs value showed positive correlations, with the AC dosage under the same temperature. Increasing adsorption temperature declined the adsorption capacity of AC, resulting in the exponentially decreased average I-TEQ value adsorbed per gram of AC, from 131.3 ng TEQ/Nm3 (150 °C) to 55.9 ng TEQ/Nm3 (180 °C). The coal-based AC used in this study preferred to adsorb lower chlorinated PCDD/Fs, tetrachlorianted dibenzo-p-dioxin and dibenzofurans (TCDD/Fs), and pentachlorianted dibenzo-p-dioxin and dibenzofurans (PeCDD/Fs) than highly chlorinated PCDD/Fs, heptachlorianted dibenzo-p-dioxin and dibenzofurans (HpCDD/Fs), hexachlorinated dibenzo-p-dioxin and dibenzofurans (HxCDD/Fs), and octachlorianted dibenzo-p-dioxin and dibenzofurans (OCDD/Fs), which was aggravated by the increasing temperature. The characterization of the surface properties of AC revealed that slight oxidation occurred on the AC surface during the adsorption process, introducing oxygen to the competitive adsorption. In addition, it was found in this study that an increased temperature led to a higher content of hydrophilic carboxyl and anhydride groups and weakened π-π interactions, which were also partly responsible for the negative impact of the increasing temperature on the AC adsorption capacity. The results of this study can contribute to the operation optimization for controlling PCDD/F emissions from municipal solid waste incineration (MSWI).

One of the major challenges in recycling plastics is the removal of undesired volatile components from the polymeric phase, which may reduce process efficiency and negatively affect product quality. Accordingly, the recycling industry employs a broad range of degassing techniques, the efficiency of which often depends on the diffusion coefficient—a measure of the mass transport of volatile components in polymeric phases. The aim of this study was to develop a practically feasible experimental approach using thermogravimetric analysis (TGA) to determine the average diffusion coefficient of volatile components in polymer waste materials. First, the TGA method was validated with a pressure decay apparatus (PDA) using predefined binary material mixtures: Thin sheets were pressed from virgin high-density polyethylene (HDPE) and polypropylene (PP) and deliberately saturated with toluene in a sorption experiment. These saturated samples were then used in TGA and PDA desorption experiments at 60 °C, 80 °C and 100 °C, which yielded similar results with an average difference of 7.4% for the HDPE-toluene system and 14.7% for the PP-toluene system. When validated, TGA was employed to determine the diffusion coefficient of volatile components in post-industrial plastic waste melt at a temperature of 220 °C. The proposed method contributes to the understanding of diffusion-based mass transport in polymer waste materials and provides a key parameter for model-based process control and optimization. In practice, the diffusion coefficient results can be used to predict the degassing performance of an extrusion process in the mechanical recycling of plastic waste.

As an integral part of the EU’s Green Deal, the purpose of the bioeconomy is to ensure an effective transition to meet people’s needs based on renewable resources while maintaining economic growth. This study undertakes the modeling of bioresource value scenarios in the agricultural sector and proposes a methodology to evaluate the possibilities of reaching a higher added value of bioresource products. The main objective of the study is the adaptation of the market allocation–energy flow optimization model system (TIMES) for analysis of high-value-added product production capacities in the livestock sector to reach an increase in added value for 2030 with the introduction of new technologies. The developed model is tested in a case study of the animal husbandry sector in Latvia. The results show which pathways are economically feasible to achieve value-added targets set for 2030. Although not all of the available resources are used due to local market limitations, there is significant potential for the use of animal husbandry resource waste, and it is possible to achieve about 62% higher cumulative added value from 2023 to 2030 with the production of new products (protein powder, wool pellets, and gelatin) in comparison with the base scenario.

This study focuses on producing asphalt with improved rheological properties that differ from the original asphalt and are less affected by aging conditions. The rheological properties of Qayara asphalt were enhanced by modifying the asphalt using spent rubber tire (SRT) with different percentages of anhydrous aluminum chloride. Percentages ranging from 1.0% by weight of the spent tire rubber were added after proceeding with the thermal crushing process. The percentages of anhydrous aluminum chloride catalyst were 0.4 and 0.8%, respectively. This mixture was microwaved at 270 watt of power for 4, 8, and 12 min, respectively. The measurements performed are plasticity, penetration, softening point, and penetration index. The previously mentioned measurements were also made on the modified asphalt one year after the modification process to understand the effect of aging conditions. The microstructure and thermodynamics have been characterized by FE-SEM and EDX measurements. This study provides good rheological properties of the modified bitumen binder that is aging-resistant.