Potential Reuse Research Articles

Efficient laboratory perovskite solar cell recycling with a one-step chemical treatment and recovery of ITO-coated glass substrates

The proliferation of organic–inorganic perovskite solar cells (PSCs) has garnered considerable attention due to their potential for low-cost, large-scale photovoltaic panel production. However, the inclusion of lead in PSCs poses significant sustainability challenges, necessitating effective end-of-life treatment strategies to mitigate environmental pollution and comply with electronic waste disposal regulations. In this study, we present a novel recycling system for decomposing and reclaiming the constituent materials of a typical PSC. Utilizing a one-step solution process extraction approach, we successfully preserved the chemical composition of each layer, enabling their potential reuse. This recycling method not only addresses the separation of the toxic lead component but also emphasizes the recovery of other valuable PSC layers. Notably, the commonly used hole transport layer in perovskite solar cells is Spiro-OMeTAD, which was successfully extracted with chlorobenzene, with its purity subsequently confirmed. Moreover, the removal of individual layers facilitated the retrieval of indium-doped tin oxide (ITO) conductive glass, a critical substrate in PSC fabrication. Comparative analysis of the physical and electrical properties of recycled and reference ITO substrates revealed minimal discrepancies, indicating the feasibility of reusing recycled substrates without compromising device performance. The proposed recycling technique offers a practical approach to mitigate pollution risks, minimize waste generation during the recycling process of perovskite-based solar cells, and reduce end-of-life recycling costs.

A review on the fate of micro and nano plastics (MNPs) and their implication in regulating nutrient cycling in constructed wetland systems

This review discusses the micro-nano plastics (MNPs) and their interaction with physical, chemical and biological processes in a constructed wetland (CW) system that is typically used as a nature-based tertiary wastewater treatment for municipal as well as industrial applications. Individual components of the CW system such as substrate, microorganisms and plants were considered to assess how MNPs influence the CW processes. One of the main functions of a CW system is removal of nutrients like nitrogen (N) and phosphorus (P) and here we highlight the pathways through which the MNPs influence CW's efficacy of nutrient removal. The presence of morphologically (size and shape) and chemically different MNPs influence the growth rate of microorganisms important in N and P cycling, invertebrates, decomposers, and the plants which affect the overall efficiency of a CW treatment system. Certain plant species take up the MNPs, and some toxicity has been observed. This review focuses on two significant aspects: (1) the presence of MNPs in a significant concentration affects the efficiency of N and P removal, and (2) the removal of MNPs. Because MNPs reduce the enzyme activities in abundance and overproduction of ROS oxidizes the enzyme active sites, resulting in the depletion of proteins, ultimately inhibiting nitrogen and phosphorus removal within the substrate layer. The review found that the majority of the studies used sand-activated carbon (SAC), granular-activated carbon (GAC), rice straw, granular limestone, and calcium carbonate, as a substrate for CW treatment systems. Common plant species used in the CW include Phragmites, Arabidopsis thaliana, Lepidium sativum, Thalia dealbata, and Canna indica, which were also found to be dominant in the uptake of the MNPs in the CWs. The MNPs were found to affect earthworms such as Eisenia fetida, Caenorhabditis elegans, and, Enchytraeus crypticus, whereas Metaphire vulgaris were found unaffected. Though various mechanisms take place during the removal process, adsorption and uptake mechanism effectively emphasize the removal of MNPs and nitrogen and phosphorus in CW. The MNPs characteristics (type, size, and concentration) play a crucial role in the removal efficiency of nano-plastics (NPs) and micro-plastics (MPs). The enhanced removal efficiency of NPs compared to MPs can be attributed to their smaller size, resulting in a faster reaction rate. However, NPs dose variation showed fluctuating removal efficiency, whereas MPs dose increment reduces removal efficiency. MP and NPs dose variation also affected toxicity to plants and earthworms as observed from data. Understanding the fate and removal of microplastics in wetland systems will help determine the reuse potential of wastewater and restrict the release of microplastics. This study provides information on various aspects and highlights future gaps and needs for MNP fate study in CW systems.

Magnetic metal oxide catalysts: Paving the way for enhanced antibiotics degradation in wastewater via peroxymonosulfate activation

The global challenge of removing pharmaceutical pollutants necessitates urgent attention. Advanced oxidation processes (AOPs) have been widely researched for this purpose. Peroxymonosulfate (PMS) has gained significant interest due to its ability to generate free radicals and its high efficiency and cost-effectiveness. In this study, various magnetic metal oxides (MMOs) including CoFe2O4 (CoF), CuFe2O4 (CuF), and Fe3O4 (FO) were synthesized, and their performance in activating PMS for the elimination of Cefixime (CFX) was compared with each other. The physicochemical, textural, and structural characteristics of the prepared samples were analyzed using BET, FESEM-EDS, XRD, and VSM techniques. The results revealed that CoF exhibited superior performance in the decontamination of CFX when coupled with PMS, outperforming the other catalysts. CoF also demonstrated higher reusability potential compared to CuF and FO catalysts. These findings indicate that the application of transition metal ions as heterogeneous catalysts exhibit enhanced catalytic activity in PMS decomposition compared to homogeneous forms. Overall, CoF proves to be an effective and promising catalyst for contaminant degradation in water resources when employed in the PMS activation system.

Evaluating the Circular Economy Potential of Modular Construction in Developing Economies—A Life Cycle Assessment

Circular economy (CE) is an emergent concept that promotes resource circularity in multiple product systems. Modular construction (MC), an evolving construction technique, which includes an off-site manufacturing environment, increasingly supports CE strategies such as reuse due to the elevated potential for design for disassembly (DfD). Design-stage environmental assessments are paramount in aiding the early decision making of modular construction projects to successfully plan and implement DfD strategies. Research on synergising modular construction, circular economy and environmental sustainability is rare in developing economies. Thus, the current study aims to conduct a design-stage life cycle assessment of a DfD and linear versions of a modular building unit in Sri Lanka to evaluate the potential environmental benefits. The life cycle assessment results highlight that the DfD strategy has the lowest environmental impacts in all categories, with a 63% reduction in global warming potential and an approximately 90% reduction in terms of human toxicity compared to the linear version. Further, it showed the elevated potential of reuse compared to recycling practices in improving the environmental performance. Sensitivity assessment revealed that steel was the most sensitive to the change in reuse percentage among main building materials. The analysis outcomes highlight the importance of long-term thinking, architectural design creativity and industrial and technology development to uptake the CE-driven MC in the Sri Lankan context. Finally, strategies are proposed to support the CE approach in MC in developing regions. Both quantitative and qualitative outcomes provide a basis for construction industry stakeholders, academia, and policy makers to explore further and promote modular construction practices to enhance the circularity of building materials and components in developing regions.

Potentially toxic elements in rainwater during extreme rainfall period in the megacity Beijing: Variations, sources, and reuse potential

Air pollution has become a worldwide problem, which resulted in various environmental threats to the human beings and surface ecosystem. It is thus significant to clarify the sink/source process of atmospheric contaminants, such as the potentially toxic elements (PTEs). The rainfall process is a vital sink for atmospheric PTEs, which can effectively reduce their content in atmosphere. However, the understanding blind spot of variations, sources, and reuse potential of rainwater PTEs in megacities (hotspots area of atmospheric PTEs deposition) still existed, particularly in extreme rainfall period. For this, the daily-scale rainwater samples were collected in Beijing City during extreme rainfall period, and the selected PTEs were measured and further analyzed. The results indicated a volume-weighted mean PTEs concentration (in μg/L) order of Zn (10.86) > Mn (3.21) > Fe (0.73) > Cu (0.69) > Ni (0.35) > V (0.22) > Cr (0.09) ≈ Pb (0.09) > Cd (0.04). Zn was the most abundant PTEs, which was 2∼3 magnitude orders greater than the low abundant PTEs, such as Cr, Pb, and Cd. The sources of PTEs and the dissolved processes of atmospheric components (e.g., particulate matter) were the predominant influencing factors of rainwater PTEs variations, and the rainfall amount was also the potential (not the critical) influencing factor, while the influence of rainwater pH is negligible. According to the enrichment factor and multivariate statistical analysis, the Cd, Zn, and Cu were primarily attributed to anthropogenic sources, which were typically derived from fossil fuel burning, vehicle emission, and domestic waste combustion. The crust sources mainly contributed the Fe, Cr, and V, while the other PTEs (Mn, Ni, and Pb) were derived from a combination of human and natural inputs. Reuse potential assessment revealed that the harvested rainwater was suitable for irrigation of urban green space and vegetation (low soil hazard), and may potentially be utilized for drinking purpose under extreme conditions (after addressing the problem of ammonia nitrogen). This work identified the PTEs characteristics in urban wet deposition, which will help knowledge of PTEs biogeochemical cycle and sustainable use of rainwater resources under climate and environmental change.

Investigation of sorption capacity of AMPS-(PHE-Ce)/MC hydrogel for effective removal of basic red 2 dye

Using toxic and non-biodegradable dyes in various industries has resulted in severe environmental issues and is detrimental to living organisms. To reduce the harmful effects of these contaminants, it is essential to develop efficient effluent treatment methods. Hydrogel sorbents are a promising solution to this problem due to their high efficacy, easy synthesis, quick recovery, and potential for future reuse. In this study, a hydrogel sorbent using 2-acrylamido-2-methylepropanesulfonic acid, polyhydroxyethyl cellulose, and moisiv type 5A 1/16th inches pellet (moisiv clay) [AMPS-(PHE-Ce)/MC] was synthesized. The hydrogel composite material achieved equilibrium in 24 hours by Fickian diffusion, absorbing water and expanding in size. To investigate the sorption potential of the hydrogel sorbent, the cationic probe dye basic red 2 (BR-2) was used as the target pollutant. Different isotherm and kinetic models were applied to analyze the sorption data. The analysis of the sorption data revealed that the hydrogel facilitated the chemisorption of BR-2 through the ionic interaction with the dye. The hydrogel exhibited impressive sorption capacities (1331 mg g−1), which suggests that it holds promise as an efficient solution for eliminating cationic dyes in various industrial and environmental settings.

Evaluation of Treated Wastewater Quality for Reuse in the Northern Region of Minas Gerais

Objective: This study aims to analyze the quality of effluents treated at three Wastewater Treatment Plants (WWTPs) in the northern region of Minas Gerais, evaluating reuse potential and proposals. Theoretical framework: The practice of reusing sanitary effluents holds significant economic and environmental importance. It conserves water resources allocated for higher priority uses. When assessed and compliant with regulations, effluents become potential water sources for agriculture and urban squares. The trend towards reusing treated effluents presents an alternative to meet water demands that could be satisfied with lower-quality water. Method: The study conducted laboratory analyses of three COPASA MG sewage treatment plants, referred to as WWTPs I, II, and III, between January 2021 and September 2022. Parameters crucial for effluent reuse, including Biochemical Oxygen Demand (BOD), Electrical Conductivity (EC), Hydrogen Potential (pH), Escherichia coli, Sodium Adsorption Ratio (SAR), and viable helminth eggs, were monitored and evaluated. The feasibility of proposed water reuse methods was assessed by analyzing the quality of treated effluents from the three WWTPs, considering that the treatments adhered to the conditions and effluent discharge standards outlined in Joint Normative Decision COPAM and CERH-MG No. 01 of May 5, 2008 (Minas Gerais, 2008), as well as the reuse parameters defined in Normative Decision CERH-MG No. 65/2020 of June 18, 2020 (CERH-MG, 2020). Results and Conclusion: The findings indicate that the effluents treated in the studied WWTPs are suitable for reuse, with potential corrective measures for non-compliant parameters. This allows for irrigation of urban squares, subject to approval by local authorities, and internal irrigation within interested businesses. Research Implications: This approach is highly relevant for fostering discussions on expanding reuse practices and shaping regulations through legislation, norms, and deliberations. Originality: This study stands out due to its in-depth investigation, ensuring a viable water reuse source for localities facing water scarcity, particularly in the northern region of Minas Gerais. This innovative topic, though less explored in literature, is gaining momentum in environmental discourse, thanks to the potential of effluents for agricultural purposes.

Facile solvent-free modified biochar for removal of mixed steroid hormones and heavy metals: isotherm and kinetic studies

Water contamination has become a global challenge to human survival. Non-biodegradable heavy metal cations and steroid hormones could accumulate in the human body and could result in serious health problems. In this study, we prepared biochar from waste shells of African star apples and modified biochar using a solvent-free ball milling facile method. The X-ray photoelectron spectrometer (XPS) and Fourier transform infrared spectroscopy (FTIR) analysis revealed biochar functional groups in C=C, C–O, and C=O. Brunauer Emmett Teller (BET) was used to determine the surface area, the surface area of ball-milled biochar obtained at 550 °C (BASA550) increased from 174 m2/g to 304 m2/g after modification. The Langmuir and Freundlich adsorption isotherms best described the experimental adsorption data with RL < 1 and 1/n < 1 and a high degree of agreement of R2 data; Langmuir (R2 = 0.9291–0.9992) and Freundlich (R2 = 0.9077–0.9974). The adsorption kinetic studies using pseudo-first-order and pseudo-second-order models revealed that the pseudo-second-order model accurately described the adsorption process). The application of the BASA550 for treating wastewater samples showed a good percentage of removal. The removal percentage for cadmium, nickel, and lead was recorded as 92.96%, 90.89%, and 90.29%, respectively. The percentage removal in the influent and effluent were found to be 85.06%, 83.87%, 84.73%, and 89.37%, 86.48%, and 87.40%, respectively. The maximum percentage removal of steroid hormones from ultrapure water ranged from 84.20 to 89.63%, while from the spiked effluent and influent the percentage removal of 78.91–87.81% and 73.58–84.51% were obtained. The reusability of the ball-milled biochar was investigated and the result showed that the adsorbent (BASA550) had a good reusability potential for the first four cycles.Graphical

Plasma treatment of sulfamethoxazole contaminated water: Intermediate products, toxicity assessment and potential agricultural reuse

The increasing global water demand has prompted the reuse of treated wastewater. However, the persistence of organic micropollutants in inefficiently treated effluents can have detrimental effects depending on the scope of the reclaimed water usage. One example is the presence of sulfamethoxazole, a widely used antibiotic whose interference with the folate synthesis pathway negatively affects plants and microorganisms. The goal of this study is to assess the suitability of a non-thermal plasma-ozonation technique for the removal of the organic pollutant and reduction of its herbicidal effect. Fast sulfamethoxazole degradation was achieved with apparent reaction rate constants in the range 0.21–0.49 min−1, depending on the initial concentration. The highest energy yield (64.5 g/kWh at 50 % removal) exceeds the values reported thus far in plasma degradation experiments. During treatment, 38 degradation intermediates were detected and identified, of which only 9 are still present after 60 min. The main reactive species that contribute to the degradation of sulfamethoxazole and its intermediate products were hydroxyl radicals and ozone, which led to the formation of several hydroxylated compounds, ring opening and fragmentation. The herbicidal effect of the target compound was eliminated with its removal, showing that the remanent intermediates do not retain phytotoxic properties.

Recycled carbon fiber potential for reuse in carbon fiber/PA6 composite parts

Pyrolysis reclaiming is the most promising process to treat high volumes of composite waste with an advantageous carbon footprint. This paper aims to compare pyrolysis reclaimed carbon fibers (RCF) to virgin sized fibers (VF) and de-sized fibers (VFT) in their capability to bond to a polyamide 6 matrix. Micromechanical tensile testing of single fiber samples of the three fiber types was conducted. A minor reduction in tensile strength and an unchanged elastic modulus of the RCF compared to VF was observed. Scanning electron microscopy and atomic force microscopy scans were used to evaluate the morphology of the fibers. To evaluate the surface energy of the fibers, tensiometric testing was conducted. RCF showed a better adhesion capability compared to VFT through higher total surface energy. Moreover, X-ray spectrophotometry scans highlighted a higher proportion of functional groups at the RCF surface compared to VFT. Finally, pull-out tests underlined a decrease of the interfacial shear strength of RCF and VFT by 35% compared to VF. Overall, this study’s results further the understanding of the impact of the pyrolysis reclaiming process on RCF mechanical and adhesion properties.

Design for and from disassembly with timber elements: strategies based on two case studies from Switzerland

When a timber building gets disassembled and its elements either are burned or biodegrade, the carbon stored in the timber structure gets released to the atmosphere as CO2. Reusing timber elements prevents this process from happening and thus delays the global warming caused by greenhouse gas emissions. Even if there is a long historic tradition of timber reuse in Switzerland, currently a low fraction of a timber building’s elements is being reused after its disassembly. In this study, strategies that could facilitate circular use of timber elements are analyzed. The focus lies on the design process, which is investigated from two perspectives: strategies at the start-of-life of buildings to enable new timber element cycles to emerge (design for disassembly, or DforD), and strategies at the end-of-life of buildings to keep existing timber elements cycles closed (design from disassembly, or DfromD). Two case studies of recently completed multi-story timber-hybrid buildings in Switzerland were analyzed from both perspectives. Regarding DforD, a scoring system was developed that assesses single elements according to their disassembly and reuse potential. Regarding DfromD, a building design optimization tool was created that takes dimensional design tolerances of a building as an input and proposes a procurement-optimized and structurally safe arrangement of reused elements, which are taken from an inventory that is based on the two case studies. It was found that connections between reinforced concrete and timber parts play a crucial role in terms of DforD and that building layouts with DfromD elements may vary widely according to the chosen optimization variable. In conclusion, both applications have the potential to scale up the competitiveness of reused elements.

Use of photogrammetry to survey Iron Age rock art motifs in the Côa Valley: the Vermelhosa Rock 3 case study (Vila Nova de Foz Côa, Portugal)

The Côa Valley, listed as a World Heritage site since 1998, presents over 1200 open-air engraved rock panels. TheArchaeological Park of the Côa Valley has meticulously documented these rock art motifs, employing various techniques including direct tracing processes on the rocks, using both natural and artificial lighting. However, this intensive work is highly demanding, especially considering that many of the rocks are not easily accessible. In the context of the "Open Access Rock Art Repository" (RARAA) project, this paper presents a methodology for the three-dimensional (3D) survey of rocks with rock art motifs, as well as the subsequent production of orthophotos from the resulting 3D models, accomplished through photogrammetry. These orthophotos serve as the foundation for the vector drawing of the motifs. Remarkably, the level of detail captured in these records has shown that most of the motifs are visible and can be accurately represented through the orthophotos. This has significantly reduced the time required for field surveys. However, in certain cases where specific small areas of the panel are affected by challenging lighting conditions, further fieldwork is still necessary, analogous to the direct tracing process. Additionally, this study introduces an information system designed to integrate the vector graphics and the motifs characterisation data; this supports enhanced research in the area and promotes improved open access for potential reuse in new interpretations or integration into future projects. By creating highly detailed 3D models, the authors complement the two-dimensional drawings of the surfaces and ensure the digital preservation of both the rocks and the associated iconography. These records serve as highly detailed digital surrogates that facilitate the monitoring efforts of the rocks and motifs; they also guarantee the availability of valuable resources for future research and analysis, even if natural or deliberate changes occur.

PixelFrame: A reconfigurable, precast, post-tensioned concrete structural system for a circular building economy

The demand to build for a growing urban population conflicts with the need to reduce the AEC (Architecture, Engineering and Construction) sector’s contributions to global CO2 emissions. Structural systems are a key factor in this challenge, as they contribute substantially to a building’s mass and are typically overdesigned. In this paper, we present PixelFrame, a new precast concrete structural system that is algorithmically designed to use less carbon upfront and be reused across multiple lifecycles. We achieve a high reuse potential for structural elements through building load demand analysis, a segmental externally post-tensioned design, and an integrated optimal assignment strategy. In addition to improving reuse potential, a segmental optimization strategy also yields higher efficiency in comparison to traditional prismatic concrete structural elements. The detailing of concrete mixes is informed by a statistical analysis of anticipated building load demands and a custom clustering asymmetric distance function and clustering algorithm. Compared to previous work in this area, our contribution is original in its bidirectional algorithmic approach; both the target building structure and the circular material inventory are computationally generated to achieve versatility while minimizing emissions.

Evaluation of the properties of a new circular building composite material to upcycle building wastes

A new circular composite material for building applications is developed, made of two secondary raw materials coming from waste recycling: fibers and sand. Hydraulic lime is added as a binder. This new composite targets a low environmental impact thanks to benefits of upcycling buildings waste, low energy production process, lifetime up to 60 years and of a high potential of reversibility, reuse and upcycling. The research focused on mechanical and physical properties, as well as analysis of the microstructure by X-ray 3D microtomography and in-situ compression testing. The mechanical and physical test results show good and unexpected properties: a density of 390 to 1300 kg/m3; a compressive strength between 0.2 and 2.2 MPa, a bending strength of 0.1 to 1.9 MPa and a thermal conductivity of 0.06 to 0.14 W/mK. Further research will focus on circular construction and environmental aspects. Three applications are envisioned, according the standards of the building sector.

Highly alkali caustic discharges recovery using tubular and disc type of ceramic membranes and its applicability as a near zero liquid discharge opportunity in the textile industry

Ceramic membrane technology is a good alternative for the recovery of highly alkaline and heavily concentrated caustic discharges through textile causticization processes since their high robustness. Recovery of causticization processes discharges with ceramic membrane technology has not been considered in detail in previous studies. In this study, highly alkaline and heavily polluted caustic discharges was assessed recovery and reuse potential using laboratory scale disc and tubular types of ceramic microfiltration, ultrafiltration and fine ultrafiltration membranes (0.2 µm, 300 kDa, 50 kDa, 15 kDa, 3 kDa and 1 kDa). Causticization discharges characteristics can be defined as 13 ± 0.2 pH, 21.2 ± 1 g NaOH/L, 27.9 ± 9 g COD/L, 1 ± 0.3 g TSS/L and 1785 ± 1568 Pt-Co based on long term wastewater characterization period. Required minimum MWCO membrane and membrane filtration process configuration based on permeate quality with minimum NaOH loss, membrane geometry affect, membrane fouling mechanism and economical assessment of caustic solution recovery were studied. Achievable optimum and acceptable permeate results obtained with two stage ceramic membrane filtration, 0.2 µm microfiltration followed by 15 kDa ultrafiltration permeate can be reused in the causticization process again. Steady state flux values were around 7–43 LMH at 1 bar and main fouling mechanism was the physically removable resistance according to resistance in series model, flux recovery 74% and up to 99% more after chemical cleaning and tubular type of membranes shows more fouling tendency compared to disc types. Proposed two stage ceramic membrane filtration not only provides comparable less chemical consumption but also Textile BREF documents’ caustic discharge criteria might be met with near zero liquid caustic discharge.

Are Australian Consumers Ready to Wear Recycled Clothing to Practice Sustainable Consumption?

This paper presents a comprehensive review of the extant literature to explore if Australian consumers are ready to reuse clothing as a pathway to sustainability. In this study, sustainability aspects such as collaborative consumption, apparel disposal methods, acquisition of used clothing, consumer concerns and attitudes towards reuse, and sellers’ readiness to offer sustainable solutions to clothing consumption have been explored in the context of the Australian market. The most important research contribution of this paper is the answer to whether Australia is ready to adopt the reuse of clothing through remaking and repurposing as a sustainable approach for the consumption of clothing at its end-of-life (EOL). Facilitators and challenges for the secondhand clothing sector have also been discussed. The findings highlight challenges including consumer awareness, an unwillingness to use secondhand clothing, limited recycling facilities, the availability of brand-new cheaper clothing, and the limited range of secondhand clothing. The facilitators include government policies towards recycling, fashion brands’ initiatives, and high-quality rejected clothing with the potential for reuse. It has been established that creating consumer awareness of secondhand clothing is essential to penetrate the market. Furthermore, there are ample opportunities to research consumers and the clothing reuse and recycling sector in Australia.

Towards a Cleaner Textile Industry: Using ASEC to Decrease the Water Footprint to Zero Liquid Discharge

Textile manufacturing is the second most polluting industry. It involves a series of processes that require large amounts of water and generates highly polluting wastewater. Four liquid wastes collected at different steps from two different textile factories (synthetic and natural fibers) were treated using a new disruptive technology (Adiabatic Sonic Evaporation and Crystallization—ASEC). After the treatment of the contaminated fluids, the byproducts obtained (freshwater and crystallized solids &lt;1% humidity) were characterized to determine depuration efficiency and their potential commercial reuse. The physicochemical parameters were analyzed in the liquid and solid phases. The results evidence a completely efficient separation of the contaminants and solutes from the liquids analyzed, resulting in 100% pure water with the characteristics of distilled water (an electrical conductivity below 20 µS/cm) suitable for other industrial processes or water reuses, including human consumption. This implies an estimated annual reduction in the water consumption of these factories of between 16 and 103 Olympic pools. It would also avoid the disposal of 181 and 966 ton/y dried residue by the current synthetic and natural fiber textile processing factories, respectively. More than 75% of the resulting solid residue was S from the synthetic fiber industry, and light elements from the natural fiber residues. The installation of ASEC technology in different phases or at the end of industrial textile processing lines could change the paradigm of water consumption to a minimum, thus reducing consumption and resulting in the complete recycling of water. Using renewable energy and residual heat transforms the system into a zero-pollution technology; it makes it possible to attain almost 0% CO2 emissions, fulfilling the European Green Deal objectives such as a circular economy, the decarbonization of the textile industry, the protection of the biodiversity of river basins, and zero pollution.

Facile construction of magnetic M-ZnO-Ni-RSA composite as a functional photocatalyst for tetracycline degradation: Performance and mechanism

Due to the acute contamination problem and the energy crisis, the development of high efficient, environmental-friendly, visible-light responsible photocatalyst has long been imperative to address the water pollution. Herein, we prepared a new type of magnetic catalyst (M-ZnO-Ni-RSA) via a facile combination of ultrasonic precipitation and solvothermal method. The as-prepered composite possessed high adsorption capacity, enhanced photocatalytic performance and outstanding resustability. The structural, morphological, and optical characteristics were detected by various methods, and the photocatalytic performance was systematically investigated. The results showed that the maximum removal efficiency of high initial concentration tetracycline TC (50 mg/L) over M-ZnO-Ni-RSA was up to 98.7 % within 55 min, which was faster than that of ZnO-Ni-RSA (∼94.07 % within 60 min). Except for removal efficiency and adsorption capacity, other novel and more dependable evaluation metrics including ratio of maximum adsorption capacity to the surface area(eSBET), ratio of moles of sorbents to moles in solution(qp), ratio of digration rate to photon flux(QY), ratio of molecules per photon to catalyst mass(SY) and the merit of product to energy consumed(FOM) were introduced to holistically assess the performance of the catalyst for TC removal.The incorporation of oxides facilitated interactions, thus increasing the oxygen traps and enhancing the segregation of photoinduced carriers, which were beneficial to promote photochemical activity. Besides, the doped magnetic Fe3O4 facilitated the easy separation and the potential of reusability. The EPR spin-trapping tests and radical substances quenching experiments highlighted the vital participation of 1O2, O2– and ·OH in TC removal. The initial pH, light source, catalyst dosage on the removal of TC were investigated. As expected, the M-ZnO-Ni-RSA exhibited consistent stability after five runs of TC photodegradation. Above all, the possible photocatalytic mechanism was proposed. The showed that the downstream intermediates possessed no toxicity and mutagenicity through QSAR and T.E.S.T. results. This study basically proposed a facile strategy for synthesis of efficient and stable catalyst for TC removal, thus paving the way for a promising green remediation of actual wastewater.

Biomass - metal oxide nano composite for the decontamination of phenol from polluted environment - parametric, kinetics and isotherm studies

The contamination of aqueous environment by phenol poses a major threat due to its hyper toxic effects and removal of phenol is challenging due to its hydrophilic properties. This research study examines the surface encapsulation of iron oxide (IO) with bio-derived carbon-based date palm (DP) to make date palm-iron oxide (DP-IO) nanocomposite to potentially remediate phenol in aqueous environment. Phenol removal percentage is predominantly influenced by environmental factors, namely pH, nano sorbent loading, temperature, agitation speed, and initial phenol concentration. Under optimum conditions of 30 °C and pH 7.8, 80.30% of phenol was removed using a 0.75 g/L sorbent load with 100 mg/L initial phenol concentration. Langmuir isotherm fitted well (R2 > 0.997), supporting single-layer phenol attachment with maximum bio-sorption capacity of 72.46 mg/g. A pseudo-2nd-order (PSO) kinetic model is identified to be the most appropriate for the DP-IO sorption experiment (R2>0.999). Scanning electron microscopic images, X-ray diffraction observations, FT-IR plots, and thermogravimetric analysis have been used to characterize. The removal mechanism involves unimolecular layer and chemisorption is identified as a rate determining step. The reuse potential proved that the synthesized nanocomposite as a sustainable solution for phenolic wastewater treatment.

Comprehensive insights into hydrothermal pretreatment of rice straw from physicochemical structure, organic matter transformation and hydrolysate reuse

Anaerobic digestion is an effective means of biomass utilization from solid waste, but the complex structure and low biodegradability of lignocellulose severely limit the anaerobic degradation conversion efficiency. In this study, hydrothermal pretreatment combined with chemicals was conducted to investigate physicochemical structure, chemical composition and changes, and enzymatic hydrolysis performance of rice straw under various combination hydrothermal pretreatment. The transformation mechanism of main components during alkaline-thermal pretreatment and the potential reuse of hydrolysate were further explored. Results showed that the total sugar concentration after hydrothermal pretreatment was 1.49 times higher than that after dissolution pretreatment. Hydrothermal-KOH pretreatment could destroy the waxy and siliceous layer on the straw surface. The roughness increased from 0.525 to 1.170 nm, and the average pore size 6.20 to 8.99 nm. Alkaline-thermal pretreatment could facilitate lignin dissolution and retained more cellulose and hemicellulose in the solid phase, and sugar concentration after pretreatment could reach 40.82 g/L. Porosity was affected by the dissolution of chemicals, and the pore structure also affected subsequent enzymatic hydrolysis. Dissolution of cellulose and hemicellulose resulted in a reduction in particle size and the formation of micropores, while re-aggregation and precipitation of lignin after dissolution led to the pore collapse and an increase in pore size. Furthermore, the hydrolysates contained nutrients, humic acids, plant hormones, and micronutrients, which had the potential to be developed into foliar fertilizers and reused. The results of this study will provide new insights and technical support for high-value utilization of straw.