Recycling Potential of Plastic Resources from End-of-Life Passenger Vehicles in China

A rapid increase in the number of end-of-life (EoL) passenger vehicles has led to a large amount of waste plastics in China. However, the scale and efficiency of recycling resources from EoL vehicles still restricts the sustainable and healthy development of the automotive industry. The current behavior of automotive/recycling industry entities, as well as the strategy of waste management policymakers, may depend on the potential of total recyclable resources. To reveal such recycling potential of various plastic materials in EoL passenger vehicles, we predicted total EoL passenger vehicles in China from 2021 to 2030 (used the Weibull distribution) considering passenger vehicle ownership (estimated by the Gompertz model), quantified the demand for new passenger vehicles (estimated using its non-linear relationship with income level and passenger vehicle ownership), and assessed the recyclable plastics by categories and by provinces. The results show that (i) the annual average recycled plastic resources from EoL vehicles would exceed 2400 thousand t in 2030, more than 2.5 times in 2021, showing a great recycling potential; (ii) the differences among the three scenarios are relatively small, indicating that no matter the saturation level of passenger vehicles in China would be high or low, a rapid increase of recyclable plastic resources can be expected from 2021 to 2030; (iii) at the provincial level, a considerable gap between the potential of recycling plastic from EoL passenger vehicles and the regional processing capacity. Given such great potential and regional differences, the recycling policies should be applied in stages and consider the development level and recovery pressure in each region.

The Impact of Reward—Penalty Policy on Different Recycling Modes of Recyclable Resources in Residential Waste

Facing enormous pressure from the rapid growth of waste on the environment and society, many developed countries have combined urban waste recycling systems with waste classification to reduce pollution and recycle resources. However, this technique is not well established in developing countries. From the 2000s, China has carried out many waste classification recycling projects in many pilot cities although they have yet to reach widespread success. This paper focuses on China’s Newest Waste Classification Recycling Project (NWCRP), which was first implemented in Shanghai from 2019 and has a three-echelon supply chain containing waste classification guiders (WCGs), recyclers and demanders. Firstly, two recycling modes in NWCRP are studied: the recyclers of the first mode are dominated by the recycling company (mode RC), and the recyclers of the second mode are dominated by the environmental sanitation engineering group (mode ESEG). Secondly, a reward—penalty policy is proposed, which can be implemented for WCGs or different recyclers in the two modes (RC or ESEG), and the impacts of different scenarios are also compared. The results showed that (1) with increasing reward—penalty intensity, the sorting rate and the profit show upward trends in two modes, while the subsidy efficiency of government decreases; (2) when the reward—penalty policy is implemented for WCGs, the recyclers’ recycling price decreases in the two modes; (3) all scenarios that implement the reward—penalty policy in mode RC have certain advantages in the sorting rate and profit and (4) with increasing reward—penalty intensity and target sorting rate in the reward—penalty policy, the social welfare first increases and then decreases in all scenarios. Finally, some suggestions on the recycling mode and the reward—penalty policy for establishing a 3RW recycling system are provided.

Characterisation and Environmental Value Proposition of Reuse Models for Fast-Moving Consumer Goods: Reusable Packaging and Products

Fast-Moving Consumer Goods (FMCGs) are products that are purchased and consumed frequently to satisfy continuous consumer demand. In a linear economy, FMCGs are typically offered as single-use and disposable products. Limitations in product design, insufficient collection systems, and inefficient recovery processes prevent high recycling rates. As a result, FMCGs often end up in landfill or the environment, contributing to waste accumulation, and pollution. Whilst recycling is the most common waste prevention strategy practiced by the industry, the process is limited to addressing only the final stage of the product life cycle, omitting the overproduction and consumption of materials typical of FMCGs. Instead, reuse is a strategy that is capable of extending the value of resources by slowing material flows. Novel reuse models that require the consumer to interact with durable primary packaging and products are emerging in the FMCG industry. However, the constituent elements and operation principles of such reuse models are not fully understood. The aim of this research is to develop a comprehensive characterisation of reuse models and to evaluate their potential to deliver environmental value. Method: Ninety-two reuse offerings were selected and analysed to identify their reuse system elements. The analysis led to the identification of a framework including five reuse models, which were also evaluated to establish their capability to deliver environmental value when compared to conventional single-use and disposable FMCGs. Results: Currently in the FMCG sector, reusable products are mostly durable packaging, such as bottles and containers for beverages, foods, personal and home care goods, and are infrequently durable products, such as personal and baby care goods, including razors and nappies. Three reuse models involve exclusive reuse, a behaviour by which a reusable product is used and kept by a single user throughout the product lifetime. In exclusive reuse models, users are provided with either a reusable product (model 1), a reusable product with preparation for reuse infrastructure (model 2), or access to preparation for reuse infrastructure (model 3). Two reuse models involve sequential reuse, a behaviour by which a reusable product is used by multiple users throughout the product lifetime and returned after each use to a provider. In sequential reuse models, users are provided with either a reusable product with preparation for reuse infrastructure and provider-operated recovery services (model 4), or a reusable product and provider-operated services for recovery and preparation for reuse (model 5). Whilst the five reuse models can operate standalone, some offerings were found to embed a multi-model approach. Both exclusive and sequential reuse models are capable of delivering environmental value by reducing the use of natural resources and retaining their value in the economy. In particular, sequential reuse models were found to have a greater capability to increase the share of recyclable resources by offering access to infrastructure for the closure of material loops. Conclusions: Consumers can currently access five reuse models and choose between exclusive and sequential reuse behaviours. When adopted in conjunction with recycling, reuse models can enable a more efficient consumption of FMCGs. Providing the infrastructure necessary to enable reuse and recycling is key to the successful and sustainable deployment of the reuse models.

Fabrication and Biodegradability of Starch Cell-Plastics as Recyclable Resources

Recently, cell-plastics, which are composed of unicellular green algal cells and biodegradable compounds as ingredients and fillers, have been suggested as carbon-recyclable materials instead of petroleum-based plastics. In this study, cell-plastics, fabricated with Chlamydomonas reinhardtii as an ingredient and a mixture of two types of starches (raw and oxidized starches) as a filler, were successfully stabilized as independent structures despite the quantity of algal cells being nine times more than that of starch. All starch cell-plastics were water repellent, possibly due to their bumpy surface structures. The starch cell-plastic, composed of 50% cells and 50% starch (1.5:1 of oxidized starch versus raw starch), showed 327 ± 52 MPa as Young’s modulus and 6.45 ± 1.20 MPa as tensile strength, indicating the possibility to be a suitable replacement for petroleum-based plastics. Additionally, all starch cell-plastics showed water-repellency and maintained those structures dipped in phosphate-buffered saline buffer as a water environment for 24 h, meaning that all starch cell-plastics had evaluable water resistance. On the other hand, by adding α-amylase, all starch cell-plastics were collapsed and lost the weight efficiently, indicated their biodegradability. This is the first paper to describe starch cell-plastics from their fabrication to biodegradation.

Marine polysaccharides: green and recyclable resources as wound dressings

As a green and renewable resource, marine polysaccharides have inherent nontoxicity, good biocompatibility, biodegradability, and environmental friendliness. Compared to land-based polysaccharides, marine polysaccharides occupy an absolute advantage in the process...

Closed-Loop Supply Chain Coordination under a Reward–Penalty and a Manufacturer’s Subsidy Policy

Government legislation significantly impacts closed-loop supply chain (CLSC) operations. This study examines the collection rate of and decisions on the product greening improvement level in a three-level CLSC with the government’s reward–penalty and a manufacturer’s subsidy policy. Four game-theoretic models are analyzed in order to evaluate the ways in which the policy and revenue-sharing contracts (RSCs) between the manufacturer and retailer affect the CLSC members’ optimal decisions and profits. We found that a reward–penalty and subsidy policy raise the collection rate, as well as the product greening improvement level. A manufacturer’s financial conflict of interest can be mitigated using RSCs. The RSCs between the manufacturer and the retailer also increase the profit of a recycling company that successfully coordinates the CLSC. An interesting result is that, when the RSCs are used under the subsidy policy, the collection rate is higher than it is in a centralized model. We also found that the subsidy level needs to be adjusted according to the price of the recycling resources, and that increasing the value of the recyclable resources and lowering the recycling costs in the early stages of the supply chain collaboration could lead to higher environmental sustainability. These results illustrate that using an RSC can effectively coordinate the CLSC, and can thus help policy implementation by governments.

Green Construction and other Sustainability Trends

Sustainable development is a hot topic in today’s world since it could help us to meet the needs of today without compromising the ability of future generations to meet their own needs. As a civil engineering student, to meet our needs, we must be willing to learn and adapt and to continue to do so in the future. For example, infrastructures for changing climate, and earthquake and flood resistant buildings. It is our responsibility to be innovative in our practices and find solutions for the issues that our planet faces. Green material plays a key role in sustainable development. They are the local and renewable materials that are used to construct energy efficient structures. Green buildings are not just about little more efficiency. But it creates less waste and greenhouse gases and supports clean environment and healthy living. Materials, energy, water and health are the key elements of green building. This paper is a review on green materials and green construction and its importance in growing sustainability trends. It is a question that disturbs minds of civil engineers around the world that how could construction industry bother sustainability. Construction industry, from energy usage to emissions, by its very nature is a large user of natural resources. Besides having potential for building over wild habitats, it also has larger environmental impact. It uses fossil fuels for its heavy machinery. World’s 36% energy usage and 40% CO2 emissions are solely from construction industry. Thus, this industry is under pressure to decrease its environmental impact. So, usage of renewable and recyclable resources, and reducing energy consumption and waste should be the major goals of this industry which could fulfil the idea of green construction. It should also adhere to the idea of Corporate Social Responsibility- the idea that business should support good causes.

The Synergistic Effects of Humic Substances and Biofertilizers on Plant Development and Microbial Activity: A Review

Agroecosystem and ecological cycling loops are open when considering the reutilization of inputs applied in farming areas. Non-renewable resources have been transformed or relocated from the air, water and land into the system and are flowing out as wastes rather than reusable, recyclable resources. This current environmental situation is promoting the development of methods able to optimize nutrient cycling, minimize use of external inputs, and maximize input use efficiency. Some humic products are derived from lignin found in wheat straw and biofertilizers as compost and manure teas can be made using residues. Also, these biostimulants might decrease the necessity of synthetic inputs. This review strives to enhance our understanding of the conjunctive use of humic substances (HS) and biofertilizers. The biostimulant effects of each of these compounds are shown in the literature. Thus, our review question is whether the combined application of HS and biofertilizers can promote synergy between both compounds and potentially more efficacy. The effects promoted by using HS plus biofertilizers on plants and microorganisms are very interconnected, so sometimes these effects can be confounded. For instance, the root elongation promoted by HS might increase hyphal fungi colonization. Therefore, this review as divided in three sections: Responses of plants, fungi and bacteria. The findings indicate that the source and application rate of HS will have a strong impact on whether plant growth and microbial activity significantly improved. The microbial species and plant type also influence the response to HS. The prospects of the conjunctive use of and biofertilizers to stimulate plant development and microbial activity in agricultural systems are theoretically substantial when considering the total number of studies included in this review.

The Potential and Trend of End-Of-Life Passenger Vehicles Recycling in China

The contradiction between limited resources and rapid development in the automobile industry has been driving society to seek the supply of recyclable resources from End-of-Life Vehicles (ELVs). It has become an urgent need for vehicle recycling policymakers to have an overall understanding of the end-of-life (EoL) vehicle population, as well as for vehicle producers to note what and how they can benefit from ELV recycling. This paper estimated the potential population of EoL passenger vehicles, all recyclable resources from them, as well as the economic values of these recyclable resources. The results show that in 2030, with a lighter-weight trend of passenger vehicles, more than 26.3 million passenger vehicles will be retired with 19.1 million tons of recyclable steel and 6.2 million tons of plastics. The theoretical economic value of all recyclable resources will reach 101.3 billion yuan ($14.4 billion) in 2030, which is an average of approximately 2.4 thousand yuan ($341.8) for each EoL passenger vehicle. It is time for the vehicle producers to shift to a manufacturing mode considering such large potential of ELV recycling. The scenario analysis suggests that in the context of a light-weighting trend, ELV resource recovery in the future calls for improvement in the recycling and reuse technologies of plastics and rubbers.