Recycling Utilization Research Articles

Production, Utilization, and Evaluation of Organic Waste Recycling

Production, Utilization, and Evaluation of Organic Waste Recycling

Dynamic real-time forecasting technique for reclaimed water volumes in urban river environmental management

In recent years, the utilization of wastewater recycling as an alternative water source has gained significant traction in addressing urban water shortages. Accurate prediction of wastewater quantity is paramount for effective urban river water resource management. There is an urgent need to develop advanced forecasting technologies to further enhance the accuracy and efficiency of water quantity predictions. Decomposition ensemble models have shown excellent predictive capabilities but are challenged by boundary effects when decomposing the original data sequence. To address this, a rolling forecast decomposition ensemble scheme was developed. It involves using a machine learning (ML) model for prediction and progressively integrating prediction outcomes into the original sequence using complementary ensemble empirical mode decomposition with adaptive noise (CEEMDAN). Long short-term memory (LSTM) is then applied for sub-signal prediction and ensemble. The ML-CEEMDAN-LSTM model was introduced for wastewater quantity prediction, compared with non-decomposed ML models, CEEMDAN-based LSTM models, and ML-CEEMDAN-based LSTM models. Three ML algorithms—linear regression (LR), gradient boosting regression (GBR), and LSTM—were examined, using real-time prediction data and historical monitoring data, with historical data selected using the decision tree method. The study used daily water volumes data from two reclaimed water plants, CH and WQ, in Beijing. The results indicate that (1) ML models varied in their selection of real-time factors, with LR performing best among ML models during testing; (2) the ML-CEEMDAN-LSTM model consistently outperformed ML models; (3) the ML-CEEMDAN-LSTM hybrid model performed better than the CEEMDAN-LSTM model across different seasons. This study offers a reliable and accurate approach for reclaimed water volumes forecasting, critical for effective water environment management.

Application of the Three-Reactor Hydrogenation Process in the Recycling Utilization of Waste Lubricating Oil and Study on the Catalyst Deactivation Mechanism

In the recycling of waste lubricating oil, the rapid deactivation of catalysts during the hydrotreating process limits its industrial application. In this paper, a three-reactor process is proposed for the...

Polymers as Aerospace Structural Components: How to Reach Sustainability?

AbstractThe aerospace industry has been benefiting from the utilization of polymer materials since fiber‐reinforced polymer composites (FRPC) offer high performances at low densities compared to metals. FRPC facilitated the design of lightweight materials, which is extensively used in aviation today. Since their first integration into structural parts, FRPC has experienced exponential growth over the years and has received a special interest from manufacturing engineering. While FRPC today is a major focus in engineering, the design of polymer matrix relies on polymer chemistry. However, aircraft materials are facing a pressing issue related to sustainability, since their environmental footprint is at an alarming level. In this review, commercial thermosetting polymer composites employed in aircraft structures are exhibited from a chemistry perspective by depicting starting products and curing reactions. The potential of chemistry to help design next‐generation sustainable FRPC for structural parts by means of utilization of sustainable feedstock, energy‐efficient processing, and recycling, is disseminated.

Resource Utilization of Bovine Hair Recycling from Enzymatic Unhairing during Leather Manufacturing

With the development of enzymatic unhairing technology in the leather industry, enhancing the recycling of bovine hair is a new issue emerging in leather-making. In this work, the effects of alkali concentration, time, and temperature in the pretreatment, as well as enzyme dosage, time, temperature, and pH in the following treatment on the dissolution performance and keratin yield of bovine hair were investigated. Hence, the extraction process of keratin from bovine hair by the alkali-enzyme method was optimized. The results sho that the optimal conditions for the keratin extraction are as follows: for the pretreatment with alkali, the alkali concentration is 0.4 M, the pretreatment time is 1.0 h, the pretreatment temperature is 65°C, and for the following enzymatic treatment, the enzyme dosage is 3324 U/g bovine hair, the action time is 4.0 h, action temperature is 45°C, and the pH is controlled between 8.5-11.5. Compared with the alkali method, the alkali-enzyme method increases the keratin yield from 24.4% to 58.1%, and the alkali dosage is reduced by 50%. The prepared keratin had high in vitro antioxidant activity, which provided a new idea for the resource utilization of bovine hair waste.

Multi-Agent Reinforcement Learning Method for Disassembly Sequential Task Optimization Based on Human–Robot Collaborative Disassembly in Electric Vehicle Battery Recycling

Abstract With the wide application of new Electric Vehicle (EV) batteries in various industrial fields, it is important to establish a systematic intelligent battery recycling system that can be used to find out the resource wastes and environmental impacts of the retired EV battery. By combining the uncertain and dynamic disassembly and echelon utilization of EV battery recycling in the remanufacturing fields, human–robot collaboration (HRC) disassembly method can be used to solve huge challenges about the efficiency of retired EV battery recycling. In order to find out the disassembly task planning based on HRC disassembly process for retired EV battery recycling, a dynamic disassembly sequential task optimization method algorithm is proposed by Multi-Agent Reinforcement Learning (MARL). Furthermore, it is necessary to disassemble the retired EV battery disassembly trajectory based on the HRC disassembly task in 2D planar, which can be used to acquire the optimal disassembly paths in the same disassembly planar by combining the Q-learning algorithm. The disassembly task sequence can be completed through standard trajectory matching. Finally, the feasibility of the proposed method is verified by disassembly operations for a specific battery module case.

Environmentally friendly comprehensive recycling utilization technology of foundation engineering slurry

A set of environmentally friendly comprehensive recycling utilization technology was developed to occupy fewer land resources and realize the recycling of engineering slurry. In this study, the engineering slurry was divided into circulating and waste slurries. The technology of “desanding plus reusing of purified slurry and drill cuttings” can be adopted to the circulating slurry, and the technology of “lowering calcium concentration, pH control, flocculation separation, pressure filtration and recycling of wastewater and mud cakes” can be adapted to the waste slurry. For the purified slurry and drill cuttings obtained from the circulating slurry, the former can be directly recycled in foundation engineering, and the latter can be directly used to cultivate grass seeds, with an average germination rate of 62.22%. Wastewater and mud cakes were collected from the flocculating substances after pressure filtration. With the addition of 2% sodium bicarbonate, the wastewater satisfied the mud-making requirements of foundation engineering. Moreover, mud cakes mixed with 30–60% nutrient soil can be used to cultivate grass, with an average germination rate of 72%. The germination rate of Phi alkali grass exceeded 80% in a field trial with drill cuttings from an underground diaphragm wall project, whereas that of ryegrass and slope king grass was 100% with drill cuttings from a geothermal well project. This method can realize the comprehensive recycling utilization of all drill cuttings (or mud cakes) and purified slurry (or wastewater).

Influence of Fly Ash on the Fluidity of Blast Furnace Slag for the Preparation of Slag Wool

Using fly ash as the modifier, blast furnace slag was modified to prepare slag wool, fulfilling the goal of using one type of waste to make use of another type of waste, and it is of great significance for the comprehensive utilization of industrial bulk solid wastes and resource recycling. In the process of forming fiber from blast furnace slag, fluidity is the key factor affecting the smooth formation of fiber from slag. To explore the changes in the fluidity of modified blast furnace slag, the temperature-dependent viscosity of modified blast furnace slag with different amounts of fly ash added was measured, and the effects of fly ash addition on the viscosity, fluidity, and activation energy of particle migration, and slag structure of modified blast furnace slag were investigated. The results indicated that with the increase in the amount of fly ash added, in the high-temperature region (>1324 °C), the viscosity of modified blast furnace slag increases gradually, the fluidity decreases gradually (i.e., the fluidity becomes worse), and the suitable fiber-forming temperature range gradually widens. When the fly ash addition increases from 5% to 25%, the trend of the activation energy of slag particle migration is as follows: increase, decrease, increase significantly, decrease. When the addition of fly ash is less than 20%, the SiO2 content and slag temperature jointly affect the breakage and reorganization of oxygen bridge bonding in the silicon-oxygen tetrahedron in the slag structure. When the addition of fly ash increases to 25%, the slag temperature dominates the breakage of oxygen bridge bonding in the silicon-oxygen tetrahedron in the slag structure. When using fly ash as the modifier to prepare slag wool, from the perspective of slag fluidity and process operability, the optimum addition amount of fly ash is 15%.

Ultrasound-triggered sonocatalytic reduction of CO2 via H2Ti3O7 nanowires

Ultrasound-stimulated piezo-electrocatalysis has been studied for a period; however, the mechanism is still unclear mainly due to the coexistence with other multiple effects like sonocatalysis, which was usually ignored. In this work, with the non-piezoelectric H2Ti3O7 nanowires following the same experimental process in piezo-electrocatalysis, the sonocatalytic reduction performance of CO2 is investigated. By applying vibration under the excitation of ultrasound with various frequencies and powers, it is found that CO is the ultimate product with a selectivity of 100%, and the optimal CO yield of 8.3 μmol g−1 h−1 is achieved with the addition of sacrificial agents. The H2Ti3O7 catalysts are also found to present a good recycling utilization ability. This work indicates that the sonocatalysis effect may exist in the piezo-electrocatalytic process using the ultrasonic excitation, which is suggested to be taken into consideration when exploring the mechanism of piezo-electrocatalysis in the future.

Multi-Agent Evolutionary Game in the Recycling Utilization of Sulfate-Rich Wastewater.

Current industrial development has led to an increase in sulfate-rich industrial sewage, threatening industrial ecology and the environment. Incorrectly treating high-concentration sulfate wastewater can cause serious environmental problems and even harm human health. Water with high sulfate levels can be treated as a resource and treated harmlessly to meet the needs of the circular economy. Today, governments worldwide are working hard to encourage the safe disposal and reuse of industrial salt-rich wastewater by recycling sulfate-rich wastewater (SRW) resources. However, the conflict of interests between the SRW production department, the SRW recycling department, and the governments often make it challenging to effectively manage sulfate-rich wastewater resources. This study aims to use the mechanism of evolutionary game theory (EGT) to conduct theoretical modelling and simulation analysis on the interaction of the behaviour of the above three participants. This paper focuses on the impact of government intervention and the ecological behaviour of wastewater producers on the behavioural decisions of recyclers. The results suggest that the government should play a leading role in developing the SRW resource recovery industry. SRW producers protect the environment in the mature stage, and recyclers actively collect and recover compliant sulfate wastewater resources. Governments should gradually deregulate and eventually withdraw from the market. Qualified recyclers and environmentally friendly wastewater producers can benefit from a mature SRW resources recovery industry.

Preparation of rambutan-shaped hollow ZnFe2O4 sphere photocatalyst for the degradation of tetracycline by visible-light photocatalytic persulfate activation

With the extensive abuse of antibiotics, antibiotics can be detected in various water bodies, endangering the human living environment and leading to human health problems. Photocatalytic technology can achieve an efficient and stable removal of antibiotics in the water environment. In this work, solvothermal-calcination method prepared the rambutan-shaped hollow ZnFe2O4 photocatalysts composed of different thickness sheets at different temperatures. The as-prepared materials were applied for the photocatalytic degradation of tetracycline (TC) in the activation of persulfate (PS) under visible light irradiation. The results exhibit that when the calcination temperature is 400 °C, the ZFO-400 sample exhibits optimal photocatalytic activity based on the PS activation due to the high specific surface area, which can present more active sites. In addition, the modified ZFO-400 material can show better visible light absorption, light under the same conditions, can stimulate more light raw charge, and further enhance its photocatalytic effect. Furthermore, by adjusting the pH value of the system, more superior degradation effect was obtained, and the degradation rate of TC is up to 100% within 60 min visible light irradiation. Finally, the as-prepared photocatalytic material showed good magnetic recycling utilization.

Recycling utilization of phosphogypsum in eco excess-sulphate cement: Synergistic effects of metakaolin and slag additives on hydration, strength and microstructure

Landfilled phosphogypsum would cause severe environmental issues, but the waste can be recycled for preparing excess-sulphate cement, an eco-friendly alternative to conventional cement. This paper investigates the effect of metakaolin (0–50%) on early hydration, phase assemblages and mechanical properties of the excess-sulphate phosphogypsum cementitious materials (ESPCMs). Results indicate that metakaolin is related to a new exothermic peak and significantly shortens the induction period. Setting time of ESPCM pastes is reduced by 13%–38% with 10%–50% dosage of metakaolin. More ettringite and highly disordered C-(A)-S-H gel are characterised when metakaolin dosage is below 20%, leading to 70% increase in 28-d compressive strength. With above 20% metakaolin dosage, portlandite consumption at early stage is promoted and hydration degree at late state is reduced. It turns out that within 20% metakaolin dosage is efficient to optimise setting time and strength development of ESPCMs, where slag and metakaolin synergistically promote the formation of ettringite and C-(A)-S-H gel to bind the unhydrated cement particles effectively.

The role of public sector policy in sustainable energy efficiency: an application of dynamic modelling

ABSTRACT Environmental protection and sustainability are long-standing issues in European Union policies. In this study, we focused on public policy related to waste management. Information on waste disposal guidelines is communicated to public authorities and citizens through public policy. The crucial question is whether the implementation of this policy achieves the objectives. The present analysis was based on a dynamic model of the repeated recycling and energy utilization process of sorted paper using a coloured Petri net. This model allowed for the isolation and monitoring of energy use in relation to the input amount, enabling the investigation of the potential energy efficiency of the paper recycling process. The breakpoint was calculated in terms of energy efficiency, gradual recycling and subsequent energy use. The calculation proved that, until this breakpoint is reached, recycling does not result in greater energy savings than the direct use of sorted paper for energy production. These findings have significant implications for the design and formulation of public policy for both the European Union and national governments.

Resource Recycling Utilization of Distillers Grains for Preparing Cationic Quaternary Ammonium—Ammonium Material and Adsorption of Acid Yellow 11

Using distillers grains (DG) as raw material after pre-treatment with sodium hydroxide (NaOH) and modified with cationic etherification agent 3-chloro-2-hydroxypropyltrimethylammonium chloride (CHPTAC), cationic quaternary ammonium distillers grains adsorption material (CDG) was successfully prepared. The optimal adsorption conditions were an adsorption temperature of 25 °C, adsorption time of 180 min, amount of adsorbent at 8.5 g/L, initial dye concentration of 100 mg/L, and pH of dye solution 7.0. The structure of CDG was characterized by FTIR, EDS, SEM, BET, ultraviolet spectrum analysis, and analysis of the zeta potential, while the adsorption mechanism was studied by adsorption kinetics, isotherms, and thermodynamics. The results showed that CHPTAC modified the distillers grains successfully and induced the formation of CDG with a large number of pore structures and good adsorption effect. The highest adsorption yield was above 98%, while after eight rounds of adsorption–desorption experiments, the adsorption rate was 81.80%. The adsorption mechanism showed that the adsorption process of acid yellow 11 (AY11) by CDG conforms to the pseudo-second-order kinetic model, mainly with chemical and physical adsorption such as pore adsorption and electrostatic adsorption. Thermodynamics conforms to the Freundlich isothermal model, and the adsorption process is a spontaneous, endothermic and entropy-increasing process.

A stepwise processing strategy for treating manganese residue and the remediation of hexavalent chromium in water and soil by manganese residue-derived (Fe,Mn)C2O4

This work provides a new approach for effective treatment and utilization of manganese residue (MR), including leaching, desulfurization, and recycling of iron and manganese. The secondary residue and the acidic filtrate (pH = 0.94) composed of H2SO4 and H2C2O4 could be used as a cement material and the medium and reductant for manganese sulfate production system, respectively. Approximately 94.5% of Fe and 97.5% of Mn were recovered to produce (Fe,Mn)C2O4 composite, which had a capacity of 122.7 mg g−1 for removing Cr(VI) and a good performance in a wide pH range of 2–9. The removal of Cr(VI) by (Fe,Mn)C2O4 was attributed to adsorption, reduction, and co-precipitation. What's more, the control experiment of FeC2O4 and MnC2O4 affirmed the synergism between Mn and Fe in (Fe,Mn)C2O4 composite, attributed to that the accelerated reduction of Mn(III) by Fe(Ⅱ) and the co-reduction effect of Fe with Mn on Cr(VI) synergistically promoted the reduction of Cr(VI). Furthermore, the ability of (Fe,Mn)C2O4 for immobilizing Cr(VI) in the soil was investigated, and the result proved that (Fe,Mn)C2O4 significantly reduced the leaching and releasing risk of Cr(VI). This strategy for treating and utilization of MR has great economic and ecological benefits.

Environment-Friendly Comprehensive Recycling Utilization Technology of Engineering Slurry

Environment-Friendly Comprehensive Recycling Utilization Technology of Engineering Slurry

Effects of Alkali-Activated Algae Biochar on Soil Improvement after Phosphorus Absorption: Efficiency and Mechanism

Biochar is often used for the removal of phosphorus in wastewater. However, the improper treatment of adsorbed biochar might cause secondary pollution. In order to promote the recycling and harmless utilization of biochar with adsorbed phosphorus, a new modified biochar (ABC) was prepared from cyanobacteria in this study. The maximum adsorption capacity of ABC calculated from the Langmuir isotherm model was 38.17 mg·g−1. ABC was used to absorb phosphorus in wastewater, whose product (ABC/P) was used for soil improvement and soybean cultivation. The results showed that adding the proper amount of ABC/P could significantly increase the pH of the soil (from 6.52 ± 0.04 to 7.49 ± 0.08), organic matter content (from 34.02 ± 0.41 to 47.05 ± 0.14 g·kg−1), cation exchange capacity (from 3.01 ± 0.18 to 3.76 ± 0.07 cmol·kg−1), water-holding capacity (from 28.78 ± 0.34 to 35.03 ± 0.31%), effective phosphorus content, and total phosphorus content. Meanwhile, the soil alkaline phosphatase activity was improved. The plant height, root length, and fresh quality were promoted by planting soybeans in ABC/P-improved soil and were better than those of the control group. Therefore, ABC/P, as a new type of phosphorus fertilizer, has the potential for soil amendment for legume crops.

Experimental Study for Sand Filter Backwash Water Management: Low-Cost Treatment for Recycling and Residual Sludge Utilization for Radium Removal

Management of backwash water (BW) generated from sand filtration of groundwater naturally contaminated with iron (Fe), manganese (Mn), and radium (Ra) remains a challenge worldwide. The present study investigated the effectiveness of a low-cost clay ceramic filter for BW recycling along with residual sludge utilization for Ra removal from BW. A 15 day continuous ceramic filtration process operated at a constant flux of 2000 L/m2/d (83 LMH) showed 99% removal of Fe, Mn, and turbidity. The treated BW was found suitable for recycling back to the sand filters. Subsequently, the residual sand filter backwash sludge (BS) was collected, characterized by scanning electron microscopy (SEM) and X-ray diffraction, and examined as a potential adsorbent to the Ra. Results showed that the sludge constituted heterogeneous basic elements, with higher percentages of iron and manganese oxides. The sludge can be classified as typical mesoporous and poorly crystalline minerals consisting primarily of quartz and Mn2O3. Over 60% of Ra from the initial 2.1 bq/L could be removed by sludge in 30 min at neutral pH. The adsorption kinetics of sludge described well by the pseudo-second order model and Ra adsorption on the sludge were mainly controlled by chemisorption rate-controlling steps, intraparticle diffusion, and external mass transfer processes. Treatment of BW by low-cost clay ceramic filters and the utilization the BS for Ra removal would be a sustainable sand filter BW management practice.

Preface

We are pleased to provide you the proceedings of 2021 3rd International Conference on Resources and Environment Sciences (ICRES 2021).ICRES 2021 was held between June 5-7, 2021 in Kasetsart University, Bangkok, Thailand. Most countries still have travel restrictions due to COVID-19 pandemic around the world. The situation of COVID-19 pandemic is unpredictable and unstable. Most of countries are still fighting the COVID-19 pandemic, conference participants could not travel to attend the conference venue to do oral presentations. Therefore, ICRES 2021 was held online during June 5-7, 2021. The location of organizers is Building 38, No.1 Shilibao, Chaoyang District, Beijing, China. We used ZOOM application which made the virtual format conference come true.The conference was highlighted by four outstanding Keynote Speakers: Prof. Chi Yung Chung from University of Saskatchewan, Canada who presented a talk on “Advanced Prediction Techniques Applied to Smart Grids” Prof. Khaled M. Bali from University of California, Dvision of Agriculture and Natural Resources, USA who presented a talk on “Sustainability of Water Resources in California Under Scarcity” Prof. Kaimin Shih from the University of Hong Kong, China who presented a talk on “Persistent Perfluorochemical Pollutants in the Environment and Thermal Treatment Processes” Prof. Mohamed Benbouzid from University of Brest, France who presented a talk on “Tidal Stream Turbine Systems Resilient Control: The key to Improve Availability and Decrease Maintenance Costs”.Each oral presenter had about 12 Minutes of Presentation and 3 Minutes of Question and Answer. Conference was organized in 6 sessions with various topics: Green Technology and Sustainable Development, Waste Management and Recycling Utilization, Environmental Pollution and Control, Wastewater Treatment and Water Resources Management, Agro-Environmental Science and Geochemistry, Food Science and Agricultural Engineering.All accepted papers presented at the ICRES 2021 were included in this volume, which contained three chapters with topics: (1) Environmental Science and Sustainable Development (2) Resource Management and Waste Utilization (3) Geology and Geochemistry. All papers were subjected to peer-review by conference committee members and international reviewers. The papers were selected based on high quality and high relevancy to the conference scope.ICRES 2021 virtual conference provided an ideal platform for participants to share views and experiences in Resources and Environment Sciences and related areas.We would like to express our sincere gratitude to organizing committee and the volunteers who have dedicated their time and efforts in planning, promoting, and helping the conference. We hope that the readers would gain some valuable knowledge from this effort. We are expecting more and more experts and scholars from all over the world to join this international event next year.Prof. Khaled M. Bali,Statewide Irrigation Water Management SpecialistUniversity of California, Division of Agriculture and Natural Resources, USAJuly 19, 2021Committees are available in the pdf

Preface

2021 3rd International Conference on Environment Sciences and Renewable Energy (ESRE 2021) was held as virtual conference during June 5-7, 2021. Conference became a unique platform for leading scientists, teachers, experts and practitioners studying environment sciences and renewable energy. Conference participants were offered with numerous opportunities to present results of their breakthrough research, exchange knowledge and experiences and discuss current problems and trends.The conference is an international conference for the presentation of technological advances and research results in the fields of environment sciences and renewable energy. Its model was divided into two major parts, including keynote speeches and oral presentations, which has brought together more than 60 leading researchers, engineers and scientists in the domain of interest from Malaysia, Russia, Indonesia, India, Peru, Croatia, France, UAE, Philippines, Ethiopia, México, Portugal, Australia, Canada, China, Thailand, Italy and so on. Four distinguished experts in total have given their 45 minutes’ speech as keynote speakers for the conference. They are Prof. Chi Yung Chung from University of Saskatchewan, Canada; Prof. Khaled M. Bali from University of California, San Diego, USA; Prof. Kaimin Shih from University of Hong Kong, China and Prof. Mohamed Benbouzid from University of Brest, France. Their insightful speeches had triggered heated discussion during keynote speech session of the conference. In addition, there are 6 presentation sessions. The topics are Green Technology and Sustainable Development, Waste Management and Recycling Utilization, Environmental Pollution and Control, Wastewater Treatment and Water Resources Management, Agro-Environmental Science and Geochemistry, Food Science and Agricultural Engineering. Each presenter was allocated 12 minutes to deliver speech and 3 minutes for Q&A one by one. Only one presentation has been selected as the best one for each session.All papers presented at the 2021 3rd International Conference on Environment Sciences and Renewable Energy (ESRE 2021) are included in this volume. All the papers have been through peer-review by conference committee members and international reviewers and process to meet the requirements of international publication standard.We would like to acknowledge all of those who have supported ESRE 2021. Each individual and institutional help were very important for the success of this conference. Especially we would like to thank the organizing committee for their valuable advices in the organization and helpful peer review of the papers.Prof. Chi Yung ChungUniversity of Saskatchewan, CanadaJune 23, 2021Committees are available in the pdf