Eco-friendly Disposal Research Articles

E-waste Management Using Blockchain Technology

Introduction; Bridging the digital divide requires the provision of affordable, fair and quality ICT. With nearly two-thirds of the world’s population still offline, there is a need to provide affordable web access for everyone. For developing countries, increasing the popularity of information and communication technology has become the most important factor in reducing poverty. The danger of electrical and electronic waste disposal contains hazardous substances, but most of the electrical and electronic equipment is still disposed of in an unhealthy environment in the field development area, affecting the level of contamination in Water, Air and Soil ultimately affecting people’s health. Eliminating E-waste responsibility and protecting the environment is a challenge for countries. Smart cities can solve environmental problems through proper waste management for improving human health, protecting water resources, and reducing pollution. Objective; In this paper, we explore how blockchain technology can help smart cities to manage E-waste by providing consistency, immutability, transparency, and accountability control in a distributed, reliable, and secure manner. We discussed the advantages of blockchain technology in various aspects of E-waste management, such as instant tracking and monitoring, E-waste disposal and E-waste management regulation compliance, proper disposal management, E-waste management, and material handling, etc. All examples of disposal services, but in our study we have found that there is no fool proof system to check the disposal of E-waste whether it has been disposed off Fully or Partially. We mainly focused on the tracking of E-waste management system for 100% safe and eco-friendly disposal from the originating point of E-waste to end disposal point of total disposal. Methods; For this, we have used machine-learning model to find the existing percentage of disposal of E-waste at the end-point which reveals that it is never 100%. And partial disposal of E-waste means we have still partial E-waste around us in different forms, which will be a threat for the society to be indulged in hazardous after effects of randomly dumping E-waste.Results; After this we have modelled a Disposal Tracking System(DTS) using blockchain technology to create an E-waste data storage as Decentralized Shareable Ledger (DSL) which records the quantity and state of E-waste data from its originating point to a different level of disposal unit and finally reflect the balance of E-waste data as NIL at the end of last disposal point.Conclusion; This system will helpful for safe and ecofriendly E-waste management and it provides complete transparency and traceability of E-waste during the life cycle of complete disposal. After implementation of this system any district or Block or Village authority can ensure to its citizens for E-waste hazards free environment and safety of natural resources

Innovative Solution for Invasive Species and Water Pollution: Hydrochar Synthesis from Pleco Fish Biomass

In recent years, the invasive pleco fish has emerged as a global concern due to its adverse effects on ecosystems and economic activities, particularly in various water bodies in Mexico. This study introduces an innovative solution, employing microwave-assisted hydrothermal carbonization (MHTC) to synthesize hydrochar from pleco fish biomass. The research aimed to optimize synthesis conditions to enhance hydrochar yield, calorific value, and adsorption capacities for fluoride and cadmium in water. MHTC, characterized by low energy consumption, high reaction rates, and a simple design, was employed as a thermochemical process for hydrochar production. Key findings revealed that through response surface analysis, the study identified the optimal synthesis conditions for hydrochar production, maximizing yield and adsorption capacities while minimizing energy consumption. Physicochemical characterization demonstrated that hydrochars derived from pleco fish biomass exhibited mesoporous structures with fragmented surfaces, resembling hydroxyapatite, a major component of bone. Hydrochars derived from pleco fish biomass exhibited promising adsorption capacities for fluoride and cadmium in water, with hydrochar from Exp. 1 (90 min, 160 °C) showing the highest adsorption capacity for fluoride (4.16 mg/g), while Exp. 5 (90 min, 180 °C) demonstrated superior adsorption capacity for cadmium (98.5 mg/g). Furthermore, the utilization of pleco fish biomass for hydrochar production not only offers an eco-friendly disposal method for invasive species but also addresses fluoride and cadmium contamination issues, contributing to sustainable waste management and water treatment solutions. The resulting hydrochar, rich in solid fuel content with low pollutant emissions, presents a promising approach for waste management and carbon sequestration. Moreover, the optimized synthesis conditions pave the way for sustainable applications in energy production, addressing critical environmental and public health concerns. This research provides valuable insights into the potential of microwave-assisted hydrothermal carbonization for transforming invasive species into valuable resources, thereby mitigating environmental challenges and promoting sustainable development.

Treatment of chromium-containing sludge using sintering and ironmaking combined technology: A risk-reducing strategy for environmental impact

The efficient, safe and eco-friendly disposal of the chromium-containing sludge (CCS) has attracted an increasing concern. In this study, Co-processing of CCS was developed via employing sintering and ironmaking combined technology for its harmless disposal and resource utilization. Crystalline phase and valence state transformation of chromium (Cr), technical feasibility assessment, leaching risk, characteristics of sintered products, and pollutant release during CCS co-processing were investigated through a series of laboratory-scale sintering pot experiments and large scale industrial trials. The results showed that the content of Cr(VI) in sintered products first increased then decreased with increasing temperature ranges of 300 °C–800 °C, and reached a maximum of 2189.64 mg/kg at 500 °C. 99.99% of Cr(VI) can be reduced to Cr(III) at above 1000 °C, which was attributed to the transformation of the Cr(VI)-containing crystalline phases (such as, MgCrO4 and CaCrO4) to the (Mg, Fe2+)(Cr, Al, Fe3+)2O4. The industrial trial results showed that adding 0.5 wt‰ CCS to sintering feed did not have adverse effects on the properties of the sintered ore and the plant's operating stability. The tumbler index of sinter was above 78% and the leaching concentrations of TCr (0.069 mg/L) was significantly lower than the Chinese National Standard of 1.0 mg/L (GB5085.3–2007). The TCr contents of sintering dust and blast furnace gas (BFG) scrubbing water were less than 0.19 wt‰ and 0.11 mg/L, respectively, which was far below the regulatory limit (1.5 mg/L, GB13456-2012). The mass balance evaluation results indicated that at least 89.9% of the Cr in the CCS migrated into the molten iron in the blast furnace (BF), which became a useful supplement to the molten iron. This study provided a new perspective strategy for the safe disposal and resource utilization of CCS in iron and steel industry.

Recycling multisource industrial waste residues as green binder for cemented ultrafine tailings backfill: Hydration kinetics, mechanical properties, and solidification mechanism

Incorporating mine tailings with industrial waste residues (IWRs) is progressively used to manufacture filling materials, which provides an eco-friendly disposal method for IWRs and alleviate their impact on the environment. In this study, steel slag (5, 10, 15, 20 wt%), fly ash (5, 10 wt%) and blast furnace slag (52, 57, 65, 74 wt%) as the precursor, carbide slag (16, 18, 20 wt%) and desulfurization gypsum (0, 2, 3 wt%) as the activator were reutilized to synthesize the IWRs-based binder for cemented ultrafine tailings backfill (CUFTB). Experimental tests were conducted to determine the setting time, hydration heat release, mechanical behavior, and microstructure characteristics. The hydration kinetics and solidification mechanism were expounded correspondingly. Results elucidate that the initial and final setting time of CUFTB are respectively 12.08–13.92 h and 16.92–20 h <24 h much longer than the transport time in pipeline and meets the operational requirements of mine site. Hydration process of CUFTB includes initial dissolution, induction, acceleration, deceleration, and decline stages. As the hydration proceeds, the initial stage of CUFTB is regulated by nucleation and crystal growth (NG), and gradually shifted to interactions at phase boundaries (I) or diffusion (D). The high content of carbide slag (20 wt%) promotes the hydration reaction, resulting in the increase of heat release. IWRs-based binder hydrates to form calcite, ettringite, hydroaluminite, and gehlenite. Especially, the gel products are mainly C-A-S-H, C-(Al,Na)-S-H, C-(Al,K)-S-H with Ca/Si ratio <1, demonstrating a fundamental distinction from Portland cement. Under the bonding and padding of hydration products, tailings particles are solidified well. After curing of 28 days, CUFTB exhibit high UCS values exceeding 2.0 MPa, presenting an evident improvement of 26.70% ∼ 39.20% compared to those made of Portland cement. These findings are referential for preparation of cemented paste backfill by reutilizing IWRs in mine filling field.

Dynamic and optimal ash-to-gas responses of oxy-fuel and air combustions of soil remediation biomass

Given the global agenda of how to best meet carbon targets, how to scientifically and safely dispose post-harvest phytoremediation biomass on a large scale remains to be explored. This study sought to characterize the temperature-dependent ash-to-gas responses of the oxy-fuel (CO2/O2) and air (N2/O2) combustions of Pfaffia glomerata (PG). The two indices of thermal stability (RW) and comprehensive combustion (CCI) were weaker in oxy-fuel combustion, but with the oxy-fuel combustion reducing the activation energy required for the cellulose degradation from 290.07 to 98.83 kJ/mol. Both empirical indices and the SiO2–CaO–K2O method suggested that oxy-fuel combustion intensified the slagging and fouling risk. A combination of thermochemical equilibrium simulations and X-ray diffraction analysis verified the risk through ash-mineral transformations. The oxy-fuel conditions enhanced the stabilization of Zn in PG but without significant effect on Cd. The oxy-fuel combustion inhibited the formation of aromatics but enhanced the emission of gases, such as CO, CH4, C–O, CO, HCl, and SO2. The optimal conditions in terms of energy efficiency and reduced emissions were achieved between 522 and 1000 °C in the oxy-fuel atmosphere. This study can provide new insights into eco-friendly disposal options for soil remediation biomass in modern combustion systems.

Ethyl cellulose/carbonized spent coffee ground-based biocomposites for superior hydrophobicity and electric protection performance

Endowing naturally-derived electric protection materials with hydrophobicity is required to guarantee their service reliability under harsh environments and eco-friendly disposal. Herein, a conductive biocomposite was designed and fabricated using a melt-processable ethyl cellulose (EC) matrix, and a carbonized spent coffee ground (CSCG) filler with a nitrogen-doped sp2 hybridized carbon structure. In terms of functional groups, defects, and crystal structure, CSCG prepared at 1000 °C was the best suited for improving the electrical conductivity and electromagnetic interference shielding effectiveness (EMI SE) of the fabricated composites. The EC composite containing 70 wt% CSCG prepared at 1000 °C exhibited an electrical conductivity of 6.79 × 101 S/m, an EMI SE/thickness of 13.2 dB/mm, and a water contact angle of ∼ 104°. Therefore, the material design strategy used in this study can provide insight into the development of naturally-derived electric protection materials with hydrophobicity.

Manufacture of potassium chloride from cement kiln bypass dust: An industrial implementation case for transforming waste into valuable resources

The recirculation of chlorine within the kiln presents a major hurdle in co-processing domestic waste in cement kilns. This chlorine enrichment not only adversely affects the quality of cement, but also pose a serious challenge to the subsequent eco-friendly disposal of kiln dust. To solve this problem, a proper bypass system has been implemented in this study on a 4000 t/d new dry process cement rotary kiln, and the collection of chlorine-rich bypass dust outside the kiln (30 t/d) has been achieved. In addition, a comprehensive and innovative system has been developed, including water washing and subsequent triple-effect salt extraction, to achieve leaching of K+ and Cl from the bypass dust in the water rinsing liquid, while effectively removing harmful metal ions such as Pb2+. Finally, the extraction of high-purity KCl salt (6 tons/day, purity of 90 %) has been successfully achieved. It is worth noting that high-temperature flue gas rich in CO2 has been used to precipitate certain heavy metal ions, while steam from the waste-heat power generation system has been employed as a heat source for the potassium salt evaporation process. More importantly, all the materials, except for the KCl salt product, are returned to the cement kiln system without causing any secondary pollution. This study not only effectively addresses the negative impacts of chlorine element circulation within cement kilns during domestic waste co-processing, but also achieves a highly innovative engineering practice of transforming waste into valuable resources from kiln dust to high-purity KCl products. In brief, this work provides a reference example for future approaches to clean production, carbon reduction and resource utilization in the cement industry.

Flame retardant, heat insulating and hydrophobic chitosan-derived aerogels for the clean-up of hazardous chemicals

Leakage of hazardous chemicals often causes significant casualties, enormous economic losses, and negative social benefits. Presently, fire rescue personnel lack efficient and eco-friendly disposal materials for hazardous chemical leakage accidents. In this study, chitosan (CS) aerogels with excellent flame-retardant performance were prepared via cross-linking by two phosphorus-containing vanillin-based compounds (DV and TV). The as-prepared chitosan aerogels were lightweight and porous. The introduction of DV and TV greatly enhanced the residual char yields of CS at 700 °C and the flame-retardant performance of chitosan aerogels. TCS-5.0 possessed the best flame-retardant performance, indicating that TV was more effective than DV in enhancing the flame-retardant performance of chitosan aerogels. The greatly improved flame-retardant properties could be attributed to TV effectively promoting the residual char formation of chitosan aerogels and reducing the formation of combustible gas phase products. To improve the hydrophobicity of chitosan aerogels, TCS-5.0 was treated with solution immersion to load siloxane molecules on its surface. The water contact angle of HTCS-5.0 was 136.1°. HTCS-5.0 had a high oil absorption multiplicity, absorbing up to 31 times its own weight of chloroform. HTCS-5.0 could continuously absorb organic solvents on the water surface with the assistance of a vacuum pump, indicating that HTCS-5.0 could be used for the clean-up of hazardous chemical leakage accidents.

Optimal metal immobilization of oxygen-enriched co-combustion of Zn/Cd hyperaccumulator and textile dyeing sludge with natural or modified kaolin

Eco-friendly disposal of post-harvest and metal-enriched hyperaccumulator biomass is critical for the industrialization of phytoremediation. The addition of Al/Si-based materials, such as sludge and natural mineral additives, is intended to solve the issue of HM metal stabilization in the oxygen-enriched combustion of hyperaccumulator and slow down ash sintering. This study aimed to quantify and reveal the effects of 10% kaolin or modified kaolin on the oxygen-enriched (co-)combustions of Sedum alfredii Hance (SAH) and textile dyeing sludge (TDS) and their combustion kinetics, metal enrichment rates, and immobilization/stabilization mechanisms. The activation energies for the (co-)combustions of SAH and SAH mixed with 10% additives (ST31) were estimated at 75.84–260.97 kJ/mol and 65.58–327.59 kJ/mol, respectively. The (co-)combustion mechanism model was complex, including phase boundary, diffusion, and chemical reaction order. The co-combustion of SAH with 10% modified kaolin increased Cd and Zn immobilization by approximately 66.6% and 3.2%, respectively, compared with the theoretical data at 550 °C. The co-combustion of ST31 with 10% modified kaolin increased Cd immobilization by approximately 160.9% compared with the theoretical data at 750 °C. Obtained via thermal-acid modified treatment, modified kaolin increased the immobilization efficiencies of Zn and Cd through aluminosilicate reactions to form the stable structures (Ca–Zn–Si, Ca–Zn–Al, K–Zn–Si, Zn–Al, Zn–Si, Cd–Al, and Cd–Si) as well as physical absorption. According to the combination of the experimental, multi-objective optimization, and simulation results, SAH mixed 10% modified kaolin at 550 °C and ST31 mixed with 10% modified kaolin at 750 °C were the ideal co-combustion environment. This study can provide new insights into how to best reduce the environmental risks of the hyperaccumulator disposals through the oxygen-enriched combustion technology.

E-WASTE MANAGEMENT USING MACHINE LEARNING

-This study introduces an intelligent e- waste management system, leveraging Convolutional Neural Networks (CNNs) integrated into a user-friendly web application. The system employs CNNs for precise image recognition and classification of e-waste items, including organic, metal, glass, clothes, paper, and electronic materials. Users can effortlessly submit e-waste information through the web interface, receiving tailored recommendations for eco-friendly disposal methods. This technology-driven approach aims to revolutionize e-waste management, providing an efficient and sustainable solution for the burgeoning e-waste crisis. Key Words: E-Waste, CNN (Convolutional Neural Network), Image Recognition, Sustainable Disposal and waste management

Re-assembling Materialism, Sustainability and Subjective Well-Being: Empirical Evidence from E-Waste Disposal in an Emerging Market

Globally, electronic waste continues to grow as technology becomes central to consumers’ lives and relationships. This growth has led to a myriad of challenges such as electronic waste disposal that considerably affect the natural environment. The current article attempts to provide a fresh outlook on the link between materialism, e-waste disposal and consumer well-being often described as antagonistic concepts. Underpinned by the value-attitude-behaviour theory, the study investigates whether the role of materialism in influencing eco-friendly disposal and ultimately consumer wellbeing. The study also examines the mediating role of e-waste disposal in the relationship between materialism and well-being. Following a quantitative methodology and a cross-sectional research design, the study relied on a survey to collect data from 420 South African users of electronic and electrical equipment. Structural equation modelling analyses revealed that the adoption of eco-friendly disposal of electronic waste leads to consumer well-being even when consumers have materialistic tendencies. The present study adds empirical evidence to the co-existence and complementarity of materialism, sustainability and subjective well-being. The findings of this study inform eco-friendly policy development and proenvironmental initiatives that champion responsible e-waste management in households.

Biodegradation of low-density polyethylene (LDPE) through application of indigenous strain Alcaligenes faecalis ISJ128.

The resiliency of plastic products against microbial degradation in natural environment often creates devastating changes for humans, plants, and animals on the earth's surface. Biodegradation of plastics using indigenous bacteria may serve as a critical approach to overcome this resulting environmental stress. In the present work, a polyethylene degrading bacterium Alcaligenes faecalis strain ISJ128 (Accession No. MK968769) was isolated from partially degraded polyethylene film buried in the soil at plastic waste disposal site. The biodegradation studies were conducted by employing various methods such as hydrophobicity assessment of the strain ISJ128, measurement of viability and total protein content of bacterial biofilm attached to the polyethylene surface. The proliferation of bacterial cells on polyethylene film, as indicated by high growth response in terms of protein content (85.50µgmL-1) and viability (1010CFUmL-1), proposed reasonable suitability of our strain A. faecalis ISJ128 toward polyethylene degradation. The results of biodegradation assay revealed significant degradation (10.40%) of polyethylene film within a short period of time (i.e., 60days), whereas no signs of degradation were seen in control PE film. A. faecalis strain ISJ128 also demonstrated a removal rate of 0.0018day-1 along with half-life of 462days. The scanning electron microscope (SEM) and Fourier transform infrared (FTIR) spectroscopy studies not only displayed changes on polyethylene surface but also altered level of intensity of functional groups and an increase in the carbonyl indexes justifying the degradation of polyethylene film due to bacterial activity. In addition, the secondary structure prediction (M fold software) of 16SrDNA proved the stable nature of the bacterial strain, thereby reflecting the profound scope of A. faecalis strain ISJ128 as a potential degrader for the eco-friendly disposal of polyethylene waste. Schematic representation of methodology.

Compressive Strength of Fired Clay Bricks Incorporated with Ceramic Sludge Industry

Sludge is created during a variety of industrial processes, including industrial ceramics. Considering sludge waste is often disposed of in landfills, the expense of treating sludge waste is becoming uneconomical, and landfill area is diminishing. The industrial ceramics sludge has been identified as a potential alternative ingredient in making bricks. In this research, the optimum percentage of ceramic industry sludge incorporation with fired clay is determined according to its physical properties in order to improved compressive strength in fired clay brick. From the result shows that by incorporation of 30% of ceramic sludge into fired clay brick complied with the British Standard (BS) requirement and Eco-Labelling criteria in SIRIM ECO 023:2016 for building material usage. Therefore, ceramic sludge can be material for brick production with appropriate mix and design and as an alternative substitution of reasonable material that offers eco-friendly disposal method.

Computational investigation of erosion wear in the eco-friendly disposal of the fly ash through 90° horizontal bend of different radius ratios

Abstract In the present study, slurry erosion wear was evaluated in 90° horizontal pipe bends of various radius ratios (R/r = 2–10) through a commercial CFD code ANSYS FLUENT. For the suspension of fly ash-water, Euler–Lagrange and two way-coupling methods were employed to predict the slurry erosion wear. The flow through the horizontal bend pipe was simulated using a Standard k–ε turbulence modelling. The computational results were validated with the experimental result of the available literature. Fly ash was taken as the dispersed phase of the solid-liquid combination however water was used as the liquid phase. The fly ash particles size was taken as 150 µm. Various affecting factors, such as velocity (4–10 m/s) and solid concentration (2.5 and 7.5% by volume) of the fly ash, were also studied in this investigation. The erosion rate was maximum in the case of R/r = 4 and minimum for R/r = 10 at all velocities and concentrations. It was also found that the erosion rate increases with the increase in solid concentration and velocity.

Blended Polymer Dry Electrodes for Reliable Electrocardiogram and Electromyogram Measurements and Their Eco-Friendly Disposal Led by Degradability in Hot Water.

To increase the human lifespan, healthcare monitoring devices that diagnose diseases and check body conditions have attracted considerable interest. Commercial AgCl-based wet electrodes with the advantages of high conductivity and strong adaptability to human skin are considered the most frequently used electrode material for healthcare monitoring. However, commercial AgCl-based wet electrodes, when exposed for a long period, cause an evaporation of organic solvents, which could reduce the signal-to-noise ratio of biosignals and stimulate human skin. In this context, we demonstrate a dry electrode for a poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS)-based blended polymer electrode using a combination of PEDOT:PSS, waterborne polyurethane (WPU) and ethylene glycol (EG) that could be reused for a long period of time to detect electrocardiography (ECG) and electromyography (EMG). Both ECG and EMG are reliably detected by the wireless real-time monitoring system. In particular, the proposed dry electrode detects biosignals without deterioration for over 2 weeks. Additionally, a double layer of a polyimide (PI) substrate and fluorinated polymer CYTOP induces the strong waterproof characteristics of external liquids for the proposed dry electrodes, having a low surface energy of 14.49 mN/m. In addition, the proposed electrode has excellent degradability in water; it dissolves in hot water at 60 °C.

Efficient adsorption and reduction of Cr(VI) by a novel polyaniline modified magnetic iron-based waterworks sludge from aqueous solution

As a major solid waste from the waterworks, the iron-based waterworks sludge (IBWS) was currently disposed of in landfills or discharged into water body, causing land consumption and environment contamination. This work investigated a novel reclamation of IBWS to create a composite for aqueous Cr(VI) adsorption and reduction. IBWS was magnetized by calcination and further modified with polyaniline (PANI) to get PANI@MIBWS for enhanced adsorbent separation and Cr(VI) removal. After being characterized using advanced techniques, the composite was employed in aqueous Cr(VI) removal studies. PANI@MIBWS removed Cr(VI) in a pH-dependent manner, with the highest Cr(VI) removal at pH 2. The spontaneous and endothermic Cr(VI) elimination process by the composite was best explained by pseudo-second-order and Langmuir models. In the sequence of Cl-＜SO42-＜PO43-, increasing Cl-, SO42- and PO43- concentrations resulted in declining Cr(VI) elimination. Chemical, electrostatic adsorption, Cr(VI) reduction to Cr (III), and chelation were involved into the Cr(VI) removal from water by PANI@MIBWS. The study found that the novel composite was effective for Cr(VI)-bearing wastewater treatment and had easy regenerability and good reusability, providing not only a fresh insight into the sustainable and eco-friendly disposal of IBWS, but also useful information for Cr(VI)-bearing wastewater treatment.

Environmental Management Accounting (EMA) practices and plastic pollution control in selected food and beverage firms

This study investigated the relationship between EMA and plastic pollution control. The study concentrated on Food and Beverage manufacturing companies since they use plastic goods to package their products. Plastic products are discarded once they have served their purpose, which pollutes the environment. A quantitative approach was adopted, with 124 self-completed questionnaires being administered to financial managers, management accountants, factory accountants and chief accountants of 38 selected food and beverage manufacturing firms in Durban. The findings revealed a significant relationship between environmental information and environmentally-related activities. Environmental information also had a positive relationship with corporate environmental strategy. Moreover, a strong positive relationship was discovered between environmental information and plastic pollution control. An analysis of the link between environmentally-related activities and plastic pollution control revealed an insignificant relationship. An insignificant relationship was also discovered between corporate environmental strategy and plastic pollution control. This study suggests that companies within the Food and Beverage industry must put in place sustainable environmental strategies, whereby eco-friendly disposal initiatives must be implemented for plastic waste management.

Characterization of composite active edible film functionalized through reinforced Pimpinella anisum essential oil

This work aimed to develop biobased composite active edible film of tapioca starch-κ-carrageenan reinforced with Pimpinella anisum essential oil and to evaluate the effect of reinforcement on physico-mechanical, barrier, optical, and antimicrobial properties. Nineteen different components of oil were identified with distinct chromatogram peaks using Gas Chromatography–Mass Spectroscopy. The Minimum Inhibitory Concentration value of essential oil against standard test bacteria ranged between 0.6% and 1%. The dynamic oscillatory rheological measurements of film-forming solution revealed solid-like viscoelastic behavior. Incorporation of oil in the film caused significant (p < 0.05) increase in moisture absorption, b value, total color difference (∆E) haziness, transparency, and significant (p < 0.05) decrease in elongation at break, moisture, whiteness index, and L* value. Antimicrobial functionality by disc diffusion of treated films was found highly significant (p < 0.01). The results of the study provide a promising potential of composite active edible film with enhanced antimicrobial functionality. Novelty impact statement The new-fangled bio composite blend is functionalized with Pimpinella anisum essential oil. The study originally demonstrates the effect of incorporation of P. anisum essential oil on the quality and acceptability of unique bio-composite edible film. The formed composite active edible film can be commercially exploited to provide better quality and safety to various foods with eco-friendly disposal.

Cleaner and safer disposal of electrolytic manganese residues in cement-based materials using direct electric curing

The direct stockpiling of electrolytic manganese residues (EMR) poses a major environmental issue, and more eco-friendly disposal is urgently needed. The combination of cement solidified waste (CSW) and direct electric curing (DEC) provides a potential solution for hazard-free value-added utilization of EMR. The effects of DEC voltages and EMR dosages on mechanical properties, hydrated products, pore structure of mixture were investigated. The influencing mechanism of DEC on the properties of cement hydration was explored in-depth using TG and XRD results. The environmental and economic evolution of DEC was analyzed, and the leaching test was conducted to evaluate the immobilization of heavy metals. Results indicate that cement-EMR pastes cured in higher DEC voltage and reduced EMR dosage increase mechanical strength and improve pore structure and capillary water absorption with respect to indoor curing (IC). The increased cement dosage improves the effectiveness of CSW, while the increased DEC voltage enhances the ionic driving force. The boosted ettringite formation occurs in system after introducing DEC and amplifying the DEC voltage. The improvement of ion concentration in DEC accelerates the formation of hydration products. The CO2-e per MPa (EIF) and cost per MPa (CIF) values of paste DMP-7 cured in 12V-DEC exhibit the lowest values with respect to those cured in other voltages and IC. The decrease in the leaching amount of Mn2+ and NH4+-N as the DEC voltage increases, and the 28-d leaching concentration of Mn2+ and NH4+-N in pastes are in accordance with the national standards. The application of DEC and cement-solidified disposal for EMR could provide a potential solution for high-value and large-capacity disposal of hazardous solid waste.

Recovery of arsenic and practical utilization of aqueous phase in hydrothermal liquefaction of hyperaccumulator

Eco-friendly disposal and heavy metal recovery of hyperaccumulator are critical for the industrialization of phytoremediation. Hydrothermal liquefaction (HTL) is an effective method for treatment of hyperaccumulators. In this study, CaO/Ca(ClO)2 was used to assist arsenic recovery in hydrothermal liquefaction of As-enriched Pteris vittata L. (PVL). Arsenic was immobilized from aqueous phase to solid phase with a high recovery of 96.5%. Experiments with model compounds indicated that 11.3% of As(V) in feedstock was precipitously reduced to more toxic As(III) by electron transfer reaction in hydrochar, while 54.9% of As(III) could be converted into As(V) via the strong oxidability of ClO−. The concentration of As in the aqueous phase decreased by 89.9% with this method. To investigate practical application of the aqueous phase, pot planting experiments were conducted to investigate the dissolved organic matter (DOM) of the aqueous phase (after HTL for As recovery) for garlic growth promotion. Notably, the As content (stem-leaf, 0.31 mg/kg) of garlic treated with the aqueous phase of HTL-CaO-Ca(ClO)2 was below Food Safety Standard (GB 2762–2017). This work provides a potential route for the heavy metal recovery and practical utilization of the aqueous phase for environmentally sound disposal of hyperaccumulators.