Search Results (10)

In recent years, the demand for natural and synthetic zeolites has surged due to their distinctive properties and myriad industrial applications. This research aims to synthesise crystalline zeolites by co-recycling two industrial wastes: salt slag (SS) and rice husk ash (RHA). Salt slag, a problematic by-product of secondary aluminium smelting, is classified as hazardous waste due to its reactive and leachable nature, though it is rich in aluminium. Conversely, RHA, an abundant and cost-effective by-product of the agro-food sector, boasts a high silicon content. These wastes were utilised as aluminium and silicon sources for synthesising various zeolites. This study examined the effects of temperature, ageing time, and sodium concentration on the formation of different zeolite phases and their crystallinity. Results indicated that increased Na⁺ concentration favoured sodalite (SOD) zeolite formation, whereas Linde type–A (LTA) zeolite formation was promoted at higher temperatures and extended ageing times. The formation range of the different zeolites was defined and supported by crystallographic, microstructural, and morphological analyses. Additionally, the thermal behaviour of the zeolites was investigated. This work underscores the potential to transform industrial waste, including hazardous materials like salt slag, into sustainable, high-value materials, fostering efficient waste co-recycling and promoting clean, sustainable industrial production through cross-sectoral industrial symbiosis. Full article

With respect to peak carbon and carbon neutrality, China’s economic structure is developing towards low carbonization, circulation, and cleanliness. There is an urgent need to expand the scope of cleaner production audits, improve cleaner production efficiency, and promote cleaner production through regional coordination. The 14th Five-Year National Cleaner Production Implementation Plan proposed selecting 100 parks or industrial clusters to conduct an overall cleaner production audit innovation pilot. To promote the coordinated development of cleaner production areas, this study constructed a set of cleaner production index systems for industrial parks, established an evaluation model based on the binary semantic evaluation method, and selected an industrial park in central China as an audit pilot. The binary group ${\mathsf{\theta }}_1=(2, -0.1084)$ of the rating results was determined to be a cleaner production park. Based on the evaluation results, the clean production potential of the park was analyzed, and suggestions for clean production were put forward. Sixteen representative enterprises in the park were selected to build twenty-one ecological chains, providing reasonable suggestions for constructing a systematic and circular enterprise symbiosis network. Full article

The stable supply of renewable energy is imperative in many countries lacking domestic energy production. Thus, green energy will likely dominate future energy development trends. Taiwan’s thriving aquaculture industry presents an opportunity to integrate fisheries with electricity generation by transforming aquaculture into a symbiotic fishery–photovoltaic structure that provides stable, clean energy with potential economic benefits. This integrated model offers several advantages, such as temperature regulation and mobility, without needing to use land. However, several unexplored issues warrant further investigation. This study assessed the solar shading effects within the symbiotic fishery–photovoltaic model by comparing the growth of Litopenaeus vannamei and Chanos chanos under mixed cultivation conditions in an integrated system versus traditional fishponds. No substantial growth differences occurred for C. chanos between the systems. However, the body weight of L. vannamei was notably higher in traditional ponds versus the integrated system. Beyond evaluating the species’ growth, the aquatic environments were compared between the systems. The integrated model maintained a higher dissolved oxygen content and had lower ammonia and nitrite nitrogen levels than traditional co-cultivation. Moreover, this study provides valuable insights into the impacts of solar shading on the symbiotic fishery–photovoltaic model, shedding light on its potential benefits for nations lacking self-produced energy. Fishery–electricity symbiosis is a mutually beneficial integration of aquaculture and photovoltaics. Full article

CO₂ emissions are increasing with the expansion of export trade. Against the backdrop of the prominent trend of decarbonization in the global economy, the question of how to rise to the occasion to maintain the advantages of international trade, as well as achieving sustainable growth in export trade, has become an urgent issue for us to consider. This paper uses empirical analysis to propose and establish an econometric model of the symbiosis between carbon emissions and export trade dependence, economic structural changes and clean technology changes, based on the environmental Kuznets curve and using time series data for Guangdong Province from 2000 to 2021. The study found that there is a long-term, stable equilibrium relationship between the scale effect and technology effect on carbon emissions, and a positive relationship between the structural effect and carbon emissions. The study then constructed a symbiotic system of exports and carbon emissions from a symbiotic perspective. The Lotka–Volterra MCGP model was used to measure the evolution of the export and carbon emission symbiosis system from the optimization of three perspectives: the scale and structure of energy consumption under the dual constraints of export trade and carbon emissions, the scale of export trade under the carbon emission constraints, and the scale of carbon emissions under the export trade constraints. The results show that there is considerable room for improvement in the structure of energy consumption and carbon emissions in the current Guangdong export trade process. At the same time, this improvement can be achieved by adjusting the energy consumption structure and improving the efficiency of the system without changing the scale effect, technology effect or structural effect. Full article

The interactions between plants and microorganisms, which are widely present in the microbial-dominated rhizosphere, have been studied. This association is highly beneficial to the organisms involved, as plants benefit soil microorganisms by providing them with metabolites, while microorganisms promote plant growth and development by promoting nutrient uptake and/or protecting the plant from biotic and abiotic stresses. Piriformospora indica, an endophytic fungus of Sebacinales, colonizes the roots of a wide range of host plants and establishes various benefits for the plants. In this work, an interaction between barley and the P. indica was established to elucidate microRNA (miRNA)-based regulatory changes in miRNA profiles and gene expression that occurred during the symbiosis. Growth promotion and vigorous root development were confirmed in barley colonized by P. indica. The genome-wide expression profile analysis of miRNAs in barley root showed that 7,798,928, 6,418,039 and 7,136,192 clean reads were obtained from the libraries of mock, 3 dai and 7 dai roots, respectively. Sequencing of the barley genome yielded in 81 novel miRNA and 450 differently expressed genes (DEGs). Additionally, 11, 24, 6 differentially expressed microRNAs (DEMs) in barley were found in the three comparison groups, including 3 dai vs. mock, 7 dai vs. mock and 7 dai vs. 3 dai, respectively. The predicted target genes of these miRNAs are mainly involved in transcription, cell division, auxin signal perception and transduction, photosynthesis and hormone stimulus. Transcriptome analysis of P. indica identified 667 and 594 differentially expressed genes (DEG) at 3 dai and 7 dai. Annotation and GO (Gene Ontology) analysis indicated that the DEGs with the greatest changes were concentrated in oxidoreductase activity, ion transmembrane transporter activity. It implies that reprogramming of fundamental miRNA and gene expression occurs both in barley and P. indica. Analysis of global changes in miRNA profiles of barley colonized with P. indica revealed that several putative endogenous barley miRNAs expressed upon colonization belonging to known micro RNA families involved in growth and developmental regulation. Full article

The offshore oil extraction process generates copious amounts of high-salinity oil-bearing wastewater; at present, treating such wastewater in an efficient and low-consumption manner is a major challenge. In this study, a flat ceramic membrane bioreactor (C−MBR) process combining aerobic microbial treatment technology and ceramic membrane filtration technology was used to treat oil-bearing wastewater. The pilot test results demonstrated the remarkable performance of the combined sequential batch reactor (SBR) and C-MBR process, wherein the chemical oxygen demand (COD) and ammonia nitrogen (NH₄⁺−N) removal rates reached 93% and 98.9%, respectively. Microbial analysis indicated that the symbiosis between Marinobacterium, Marinobacter, and Nitrosomonas might have contributed to simultaneously removing NH₄⁺−N and reducing COD, and the increased enrichment of Nitrosomonas significantly improved the nitrogen removal efficiency. Cleaning ceramic membranes with NaClO solution reduces membrane contamination and membrane cleaning frequency. The combined SBR and C−MBR process is an economical and feasible solution for treating high-salinity oil-bearing wastewater. Based on the pilot application study, the capital expenditure for operating the full-scale combined SBR and C−MBR process was estimated to be 251,717 USD/year, and the unit wastewater treatment cost was 0.21 USD/m³, which saved 62.5% of the energy cost compared to the conventional MBR process. Full article

Greenhouses require large amounts of energy, which is the dominant factor making greenhouses more emission intensive than open-field cultivation. Alternative heating systems, such as combined heat and power (CHP), biogas, and industrial waste heat, are continuously being researched for reducing the environmental impacts of greenhouses. This paper assesses utilizing industrial waste heat and CO₂ enrichment in greenhouses as an example to propose “agro-industrial symbiosis” (AIS), to refer to a symbiotic co-operation between agricultural and industrial partners. The global warming potentials (GWPs) of greenhouse production using different heating systems are inadequately compared in the literature, which is the research gap addressed herein. Additionally, potential emission reductions of greenhouse production with industrial waste heat are yet to be assessed via lifecycle assessment (LCA). A comparative LCA of Finnish greenhouse tomato and cucumber production using various heating systems was conducted. Naturally, replacing fossil fuels with bioenergy and renewables significantly decreases the GWP. CHP systems result in decreased GWP only when using biogas as the energy source. Additionally, utilizing industrial waste heat and CO₂ resulted in a low GWP. These results are applicable worldwide to guide political decision-making and clean energy production in the horticultural sector. Full article

The juveniles of gnathiid isopods are one of the most common fish ectoparasites in marine habitats and cause deleterious effects on fish by feeding on host blood and lymph. Reef fishes tend to engage in cooperative interactions with cleaning organisms to reduce their ectoparasite load. Ocean acidification (OA) pose multiple threats to marine life. Recently, OA was found to disrupt cleaner fish behaviour in mutualistic cleaning interactions. However, the potential effects of ocean acidification on this common ectoparasite remains unknown. Here, we test if exposure to an acidification scenario predicted by IPCC to the end of the century (RCP 8.5 – 980 μatm pCO₂) affects gnathiid survival. Our results show that ocean acidification did not have any effects on gnathiid survival rate during all three juvenile life stages. Thus, we advocate that the need for cleaning interactions will persist in potentially acidified coral reefs. Nevertheless, to better understand gnathiid resilience to ocean acidification, future studies are needed to evaluate ocean acidification impacts on gnathiid reproduction and physiology as well as host-parasite interactions. Full article

Recycling of steelmaking slags has well-established applications, such as their use in cement, asphalt, or fertilizer industries. Although in some cases, such as the electric arc furnace (EAF) high-alloyed stainless-steel production, the slag’s high metal content prevents its use in such applications. This forces companies to accumulate it as waste. Using concepts such dematerialization, waste management, industrial symbiosis, and circular economy, the article drafts a conceptual framework on the best route to solving the landfilling issue, aiming at a zero-waste process re-design. An experimental part follows, with an investigation of the use of landfill slag as a substitute of limestone for the neutralization of acidic wastewater, produced by the rinsing of steel after the pickling process. Neutralization of acidic wastewater with both lime and slag samples was performed with two different methods. Two out of four slag samples tested proved their possible use, reaching desired pH values compared to lime neutralizations. Moreover, the clean waters resulting from the neutralizations with the use of both lime and slag were tested. In terms of hazardous element concentrations, neutralization with slag yielded similar results to lime. The results of these trials show that slag is a potential substitute of lime for the neutralization of acidic wastewater. Full article

Anoectochilus roxburghii (Wall.) Lindl. (Orchidaceae) is an endangered medicinal plant in China, also called “King Medicine”. Due to lacking of sufficient nutrients in dust-like seeds, orchid species depend on mycorrhizal fungi for seed germination in the wild. As part of a conservation plan for the species, research on seed germination is necessary. However, the molecular mechanism of seed germination and underlying orchid-fungus interactions during symbiotic germination are poorly understood. In this study, Illumina HiSeq 4000 transcriptome sequencing was performed to generate a substantial sequence dataset of germinating A. roxburghii seed. A mean of 44,214,845 clean reads were obtained from each sample. 173,781 unigenes with a mean length of 653 nt were obtained. A total of 51,514 (29.64%) sequences were annotated, among these, 49 unigenes encoding proteins involved in GA-GID1-DELLA regulatory module, including 31 unigenes involved in GA metabolism pathway, 5 unigenes encoding GID1, 11 unigenes for DELLA and 2 unigenes for GID2. A total of 11,881 genes showed significant differential expression in the symbiotic germinating seed sample compared with the asymbiotic germinating seed sample, of which six were involved in the GA-GID1-DELLA regulatory module, and suggested that they might be induced or suppressed by fungi. These results will help us understand better the molecular mechanism of orchid seed germination and orchid-fungus symbiosis. Full article