Low-energy and efficient resource recovery from urine is critical for sustainable sanitation and resource recycling, but most prevailing technologies remain energy-intensive and inefficient. Solar-driven aerogel-based interfacial evaporation, with ultralow energy consumption, electricity-free operation and simplicity, holds substantial potential to replace these processes. Herein, we pioneer an efficient resource recovery strategy based on this technology, and demonstrate its feasibility through a novel modular solar-driven aerogel interfacial evaporator (MSAIE). The modular configuration integrates a gradient-structured photothermal module with a vertical-structured water-supply module, breaking the inherent coupling of water transport and heat loss in conventional evaporators, and achieving an evaporation rate of 2.51 kg center dot m- 2 center dot h- 1-21.12 % higher than that of conventional evaporators. Further optimization of module height and composition enhanced water-thermal management coordination, achieving balanced water-heat utilization and ambient heat energy harvesting. Consequently, the optimized MSAIE achieved maximum evaporation rates of 3.41 kg center dot m- 2 center dot h- 1 for real urine under 1-sun illumination (1 kW center dot m- 2). By harnessing solely solar and ambient heat energy, MSAIE attained 105.56 % excellent energy efficiency. It only takes one step to produce acid-stabilized urine into concentrated fertilizer and high-quality reclaimed water, with resource recovery reaching 90.59 % (N), 85.59 % (P), 90.19 % (K), and 70.15 % (water). The MSAIE maintained stable performance and no scaling under long term operation and natural sunlight. This study provides a sustainable strategy for decentralized sanitation and resource recycling, particularly in off-grid or resource-limited regions.

Anaerobic digestion (AD) is a promising technology for energy recovery from waste-activated sludge (WAS), yet its efficiency remains constrained by poor biodegradability and limited substrate accessibility. Pretreatment processes can enhance sludge disintegration and improve methane production, but their energy efficiency and large-scale feasibility remain uncertain. In this study, the impacts of microwave pretreatment (MP) and conventional pretreatment (CP) on sludge characteristics and AD performance were systematically investigated using integrated experimental and analytical approaches. Both pretreatments significantly enhanced methane yields, with moderate microwave intensity (MP600) achieving the highest improvement (69.1 %) compared to CP (57.9 %) and high-intensity microwave treatment (MP1000, 62.8 %). Multi-scale characterisation using fluorescence excitation-emission matrix (EEM) spectroscopy with parallel factor analysis (PARAFAC) and self-organising maps (SOM), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and multi-omics analyses revealed that microwave pretreatment effectively disrupted sludge microstructure, promoted solubilisation of organic compounds, and induced beneficial microbial community shifts that facilitated hydrolysis and methanogenesis. A full-scale energy assessment further confirmed the process feasibility, demonstrating that all pretreatments yielded positive net energy gains. MP600 achieved the highest net balance (13.97 kJ/gVS), surpassing CP (13.22 kJ/gVS) and MP1000 (13.30 kJ/gVS). These results highlight that low-power microwave pretreatment offers the most favourable trade-off between enhanced methane recovery and energy efficiency, representing a technically and economically viable strategy for sustainable sludge management and bioenergy generation.

Pyrolysis is an effective approach for treating fecal sludge (FS) and converting it into useful biochar. Dissolved organic matter (DOM) is an active component of biochar, but the effects of the pyrolysis temperature on its molecular composition, transformation characteristics, and phytotoxicity require further investigation. This study investigated the temperature-driven evolution of DOM composition using spectroscopic techniques and Fourier-transform ion cyclotron resonance mass spectrometry, in conjunction with two-dimensional correlation spectroscopy, self-organizing maps, and paired mass difference analysis. Furthermore, the phytotoxicity of DOM was evaluated through seed germination tests. Results show that as pyrolysis temperature increased from 300 degrees C to 700 degrees C, dissolved organic carbon (DOC) decreased from 57.10 to 1.47 mg center dot g-1, and SUVA254 dropped from 8.54 to 0.08 L center dot mg- 1 center dot m- 1, indicating reduced aromaticity. At the molecular level, increasing the pyrolysis temperature decreased the relative contents of CHON compounds, lignin, and unsaturated phenolic components and increased the relative contents of CHO compounds, proteins, and saturated alkanes. Lignin was the main reactive precursor at 300 degrees C-600 degrees C, and proteins dominated at 600 degrees C-700 degrees C. At 400 degrees C-600 degrees C, DOM underwent notable thermal reactions that converted aromatic and toxic components into compounds with lower aromaticity and toxicity. Functional groups such as C-O, C--C, and C--O exhibited notable reactivity within this temperature range. Seed germination tests confirmed that DOM exhibited notably lower phytotoxicity when formed at 600 degrees C-700 degrees C compared to lower temperatures. These findings provide a foundational basis for optimizing the pyrolysis process for FS and safely utilizing its recovered resources.'

Trace low-molecular-weight emerging contaminants (LMWECs) in drinking water sources pose chronic health risks but remain challenging to remove using conventional treatment processes. Here, we describe an amoeba-inspired nano-robot (NRm, where m refers to the molar ratio of Fe:Si), engineered with flexible polymer chains and iron (hydr)oxide nanodomains, for the simultaneous capture and catalytic degradation of 20 representative LMWECs at initial concentrations from 100 ng/L to 1 mg/L in a real surface water. Under optimized operational conditions, NR10 achieved over twice the removal efficiencies compared to conventional water treatment chemicals involving FeCl3 and polyacrylamide (PAM). The nano-robot autonomously extended polymer "pseudopodia" to bind LMWECs into flocs via hydrophobic association, and used H2O2 both as a "propulsion fuel" and as a source of •OH radicals via Fenton-like reactions to accelerate degradation of captured LMWECs. This multi-function mechanism enabled efficient capture and degradation of LMWECs, while reducing toxicity (from "acute" of raw water to "nontoxic" of the treated water) and improving sludge dewaterability. After use, 91% of NR10 could be recovered from flocs, and the recovered nano-robots maintained high LMWEC REs with only ∼2% reduction for each recovery-reuse cycle. NR10 offers a deployable, infrastructure-compatible solution to the growing problem of LMWECs in drinking water.

Microplastics (MPs) are characterized by multiple attributes such as morphology and polymers that enable diverse classification approaches. The source apportionment of MPs is significantly different from that of traditional pollutants, whose classification relies solely on chemical composition. Current research lacks quantitative methods in microplastic source apportionment, with receptor models' reliability unverified and optimal classification approaches unclear. In this study, the performances of receptor models (Principal Component Analysis-Multiple Linear Regression (PCA-MLR) and Positive Matrix Factorization (PMF)) combined with classification approaches (polymeric and morphological) across source types (primary and secondary) and complexities (2-6 sources) were evaluated based on 56 scenarios. Results showed that PCA-MLR using morphological classification failed to resolve actual source profiles in all scenarios, with the Pearson correlation coefficient (r) between simulated and true profiles below 0.3. Under polymeric classification, PMF consistently yielded simulated source profiles significantly correlated with true values (p < 0.01) across all scenarios, with r ranging from 0.823-1.000. For ≤ 4 sources, PMF using morphological classification also performed well, potentially exceeding polymer-based results. The models exhibited distinct preferences in evaluating source impact intensities: PCA-MLR better resolved primary sources (r = 0.990 ± 0.013) than secondary sources (r = 0.973 ± 0.037), while PMF excelled for secondary sources (r = 0.990 ± 0.010) more than primary sources (r = 0.959 ± 0.055). Building on these findings, we developed an operational decision tree strategy optimizing model-classification pairing upon target source type and complexity. This framework significantly enhances the efficiency and accuracy of microplastic source apportionment, providing critical support for precise source-specific risk mitigation in aquatic environments.

Microbial lipids derived from organic waste fermentation broths offer a promising route for sustainable biodiesel production. However, yields are often limited by broth-derived stressors and the need for costly pre-treatment. In this study, we rebalance carbon and nitrogen fluxes to improve lipid enrichment by Yarrowia lipolytica cultivated on volatile fatty acid (VFA)-rich food waste (FW) broths. We first delineated lipid-accumulation performance across 20-75 g/L VFAs concentrations and a range of carbon-to-nitrogen (C/N) ratios in a defined medium. We then produced VFAs from organic waste and implemented the co-fermentation of FW with rice straw (RS) to refine the C/N balance. Compared with FW mono-fermentation, FW/RS co-fermentation at a 2:1 ratio increased the lipid concentration from 1.94 to 2.31 g/L and lipid content from 47 wt% to 59 wt%. Optical photothermal infrared (O-PTIR) spectroscopy indicated a shift in cellular metabolism toward lipid storage under an optimized flux regime. Consistently, transcriptomics revealed strengthened detoxification and antioxidative programs, ion homeostasis, and nitrogen limitation-associated regulation, alongside the repression of lipid-degradation pathways, supporting lipid accumulation by alleviating inhibitor stress and reinforcing carbon flux redistribution. These results demonstrate that organic waste co-fermentation guided by reverse carbon and nitrogen regulation is an effective strategy for upgrading waste-derived fermentates into lipid-producing substrates, and provide mechanistic insight into how the selected hydrolysate promotes lipid accumulation in Y. lipolytica.

The Chinese steel industry, as a major energy-intensive sector and a significant source of emissions, faces increasing pressure to enhance energy efficiency and reduce environmental impact. This study develops thermal system models for different heating sections of a steel rolling furnace, incorporating the characteristics of mixed gas properties and billet heating dynamics. Dynamic fuel consumption and system thermal efficiency were determined for various natural gas-biogas ratios by applying a Monte Carlo algorithm under realistic operating conditions. The findings indicate that pure natural gas achieves the highest thermal efficiency, while increasing the biogas proportion from 0 % to 100 % results in a 9.80 % efficiency decline. A life cycle assessment quantified the environmental impacts of biogas and natural gas utilization, revealing that substituting pure biogas could mitigate CO2 emissions by 14.78 t CO2 eq, assuming no production constraints. Economic analysis, integrating gas and carbon pricing, determined an optimal fuel mix of 29.29 % biogas at a natural gas price of CNY 2.70/m3, yielding a fuel cost of CNY 106.88 per ton of steel. Multi-objective optimization, considering combustion performance, environmental impact, and cost, demonstrated that at a fixed natural gas price of CNY 3.50/m3, pure biogas provides the most sustainable solution, though practical availability supports only a 61.71 % substitution. Overall, the findings provide comprehensive insights into the trade-offs among performance, environmental impact, and economic objectives when substituting natural gas with biogas in steel rolling furnaces, thereby supporting collaborative low-carbon development between steel mills and biogas plants.

High concentrations of volatile fatty acids (VFAs) derived from organic waste represent a promising carbon source for oleaginous yeasts. Nevertheless, the response mechanisms and concentration thresholds of oleaginous yeasts to high VFA concentrations remain unclear. In this study, a potential strain was selected to analyze the acid tolerance mechanism of oleaginous yeast based on their VFA utilization ability. Among tested strains, Yarrowia lipolytica showed more significant lipid conversion from acetic, propionic, and butyric acids compared to Rhodotorula toruloides and Rhodotorula glutinis. At 20 g/L VFAs, Y. lipolytica achieved a lipid yield of 1.35 g/L and a lipid content of 44.39 %. Its lipid production and tolerance mechanism were further analyzed across a wide VFA concentration range (2.5-75 g/L) using optical photothermal infrared (O-PTIR) spectroscopy. O-PTIR analysis revealed dynamic subcellular metabolic adaptations, including intensified lipid-associated ester C=O peaks and structural diversification of proteins with increased beta-folding and alpha-helix conformations. Cells in high-VFA environments maintained efficient carbon allocation toward lipid synthesis, as evidenced by lipid/protein intensity ratios comparable to low-concentration conditions. Spectral splitting in Amide I regions also indicated potential metabolite production or enzymatic activation. This study elucidates the acid tolerance mechanisms of oleaginous yeasts and underscores the utility of O-PTIR for probing microbial metabolic responses.

Microplastics (MPs) have emerged as contaminants of increasing concern in water and wastewater treatment systems because of their persistence, mobility, and potential risks to ecosystems and human health. This review critically examines two major technological routes for MP control: separation-based removal, including coagulation, filtration, membrane separation, and adsorption, and degradation-based transformation, including advanced oxidation processes and biological degradation. Under optimized conditions, separation technologies can achieve over 95% retention, while degradation technologies can induce polymer-chain scission, surface oxidation, and mass loss. This review reveals a fundamental distinction between these two routes. Separation-based technologies mainly transfer MPs from the aqueous phase to flocs, sludge, membrane retentates, or spent adsorbents, thereby concentrating particles rather than destroying the polymer structure. In contrast, biodegradation and transformation technologies aim to transform polymer chains into lower-molecular-weight products, but complete mineralization is rarely achieved under realistic treatment conditions. Incomplete degradation may generate oligomers, organic acids, aldehydes, ketones, and released additives, whose environmental fate and ecotoxicity remain insufficiently understood. Therefore, the commonly reported removal rate is insufficient for evaluating the actual environmental benefit of MP treatment, as it may represent phase transfer rather than risk elimination, or partial transformation rather than complete degradation. Overall, this review concludes that meaningful evaluation of MP treatment requires a shift from single-parameter efficiency metrics to mass-balance-based and toxicity-informed frameworks that account for the fate of both separation residues and degradation products. Future research should move beyond single efficiency metrics and establish integrated assessment frameworks based on mass balance, life cycle analysis, product identification, toxicity evolution, and residual management. Coupling efficient separation with controlled deep degradation offers a promising direction for advancing MP treatment from efficient interception towards verifiable risk reduction and sustainable control.

Public toilets are an integral part of sustainable urban sanitation infrastructure, public health protection, and inclusive public space. SDG 6.2 calls for adequate and equitable sanitation and hygiene for all, with particular attention to women, girls, and people in vulnerable situations. This study evaluates the operational status of public toilets in central Beijing in the context of the toilet revolution. A six-dimensional quantitative scoring system was developed for metropolitan public toilets based on Maslow’s hierarchy of needs theory. The average score of public toilets in the central urban area is 0.858, 0.545, 0.648, 0.443, 0.422, and 0.400 in the six dimensions of need, which is consistent with a gradient in user satisfaction across need levels. Consistency analysis indicates no significant difference (p > 0.05) in the distribution of scores for each dimension in urban areas, whereas significant differences were observed between tourist and residential areas in the dimensions of physiological excretion and convenience and comfort. The findings suggest that future upgrades should place greater emphasis on higher-order user needs, particularly dignity, equality, and user comfort. This study provides a reference for promoting the high-quality development of sanitation services. It also provides sanitation providers and policymakers with new ideas for toilet renovation, such as improving public toilet service and sanitation management through “micro-updates” and “on-site sanitation systems”.

Single-atom catalysts offer promise for emerging contaminant (EC) removal but remains limited by poor scalability due to costly precursors and complex synthesis. On the other hand, how to utilize cyanobacteria sludge from eutrophic lakes is still a challenge. Here, we report a scalable and environmental-relevant strategy to convert cyanobacterial sludge (from a full-scale eutrophic water treatment plant by FeCl3-coagulation-flotationdewatering) into particle electrodes (KCBC800) containing representative and energetically favorable singleatom para-Fe-N2O2 sites, without addition of exogenous substance during pyrolysis. Deployed in a threedimensional electrochemical reactor, KCBC800 exhibited efficient removal of 11 representative pharmaceuticals via in-situ reactive oxygen species generation, with higher kinetic rate constants, lower operating voltages, reduced energy consumption and reduced acute toxicity of treated water, compared to commercial activated carbon and conventional particle-free electrochemical system. The performance displayed strong robustness to a wide pH range (2-8), co-existence of various inorganic ions and natural-organic-matter, and in different water matrix (river and tap water). The most plausible mechanism supported by both direct and indirect experimental evidence revealed that the KCBC800 enabled EC removal by anodic catalytic & sdot;OH generation, and cathodic catalytic H2O2 production for subsequent Fenton-like reactions, without exogenous oxidant addition. This work integrated waste valorization, environmental catalysis, and circular economy principles to offer scalable sustainable water treatment solutions.

Fecal sludge (FS) management in sub-Saharan Africa (SSA) faces financial, technical, and logistical barriers. Despite rapid urbanization, onsite sanitation (OSS) systems remain the primary option for many households, yet often encounter operational challenges across the FS chain, from emptying to disposal, underscoring the need for effective interventions. A systematic review of 93 studies was conducted; 53.8

This study investigates how accelerated weathering influences the pyrolysis behavior of a bio-based composite prepared from high-density polyethylene (HDPE) and lignocellulosic ethanol-processing residue (EPR). The composites were subjected to xenon-lamp exposure for varying durations and subsequently analyzed using thermogravimetric analysis (TGA), TG-FTIR, Py-GC/MS and kinetic modelling. TGA results showed that weathering enhanced the crystallinity of the HDPE phase and reduced the maximum mass-loss rate, indicating inhibited volatilisation in the HDPE-dominated decomposition region. Iso-conversional kinetics further revealed a conversion-dependent response: the apparent activation energy decreased in the low-to-mid conversion region dominated by the residue fraction, whereas the activation energy associated with the HDPE-dominated region increased, consistent with crystallinity-enhanced resistance to polyethylene chain scission. The increased residual mass after aging is attributed not only to pre-loss/leaching of labile fractions during weathering but also to the formation of more stable residue structures (e.g., photo-induced crosslinking and lignin-derived condensed aromatic clusters) that persist during pyrolysis. TG-FTIR indicated a general decline in the intensity of functional-group absorption peaks, reflecting attenuated volatilization of both polymeric and lignocellulosic structures. Py-GC/MS demonstrated significant changes in product distribution: weathered samples generated higher yields of short-chain hydrocarbons such as propene, 1-pentene, and 1-decene, while oxygen-containing compounds (e.g., alcohols, esters, phenols) were reduced. These results clarify how controlled weathering alters the structural and chemical evolution of HDPE–EPR composites during pyrolysis. The findings provide new insights for optimizing thermochemical recycling and energy-recovery strategies for residue-derived or weathered bio-plastic composites.

The processes of organic and nutrient removal are generally well known; however, the intricate biochemistry of wastewater and its interactions with microbial communities require the creation of advanced physicochemical-biological mechanistic models. These models are currently implemented in commercial software used for simulating wastewater treatment plants (WWTPs). Such software requires various input parameters, some of which are difficult, costly, and time-consuming to obtain. As a result, modellers must make assumptions about wastewater characteristics and its components, as well as understand the interactions among different variables. These factors can introduce uncertainty into predictions of effluent quality. Therefore, finding simplified yet accurate methods remain essential for the industry. In this study, data-driven machine learning (ML) techniques were employed to model the interstage effluent quality of a large-scale WWTP. Methods such as Random Forest (RF), Decision Tree (DT), Linear Regression (LR), and K-Nearest Neighbours (KNN) were used. Results indicate that ML approaches offer a faster, more reliable way to predict effluent quality, reducing uncertainties associated with complex mechanistic models. Among these, DT and RF proved most effective, showing strong correlation with experimental data, with R 2 scores from 0.971 to 1.00. The LR and KNN models showed significant deviations from the experimental data, suggesting that DT and RF are more dependable for predicting both interstage and final effluent quality in wastewater treatment processes.

Black liquor (BL), the alkaline effluent from straw pulping, is rich in lignin with diverse molecular weights but poses serious environmental challenges. Here, a stepwise acid-assisted flocculation (AAF) strategy was developed for fractional lignin recovery and water treatment, in which a quaternary-ammonium-modified lignin flocculant (L-CTA) was employed following the "using-waste-to-treat-waste" principle. Through sequential AAF, high-(>5000 Da), medium-(1000-5000 Da), and low-MW (800-1000 Da) lignin fractions were selectively recovered (recovery rates of 91.7, 88.0, and 89.5%, respectively) under mild conditions. Structural analyses revealed a molecular transition from beta-O-4-rich, syringyl-dominated, and compact product of high-MW fraction, to more oxidized and guaiacyl-enriched low-MW lignin fractions with lower thermal stability. Mechanistic studies, by a combination of instrumental analyses (zeta potential, quartz crystal microbalance, and isothermal titration calorimetry) and theoretical computations (density functional theory and molecular dynamics), demonstrated that the AAF process followed enthalpy-entropy compensation: high-MW lignin separation relied on both an enthalpy reduction of electrostatic attraction and entropy increases of bound-water release during pi-pi stacking, whereas low-MW lignin favored an enthalpy-dominated process. This study provides a mechanistic-guided and environmental-benign route for simultaneous primary treatment of BL and fractional recovery of lignin, thereby contributing to sustainable development within the pulping industry.

Microplastics (MPs) and nanoplastics (NPs) are ubiquitous emerging contaminants in water; their environmental impacts, risks, and treatment performance strongly depend on particle-state (particle size, aging status, oxidation level, surface chemistry, colloidal stability, biological/organic coatings, and contaminant affinity). Environmental aging progressively and irreversibly reshapes the surface chemistry, morphology, and bulk polymer integrity of MPs and NPs. These transformations act as a mechanistic bridge linking (i) ecological risks, via altered transport, biological interactions, size-resolved toxic pathways, additive leaching, and amplified vector effects with co-pollutants, to (ii) treatment performance, by the changing aggregation/coagulation behavior, adsorption affinity, membrane retention and fouling, and reactivity toward advanced oxidation and bio-utilization. While previous literature on aging, ecological risks, and removal technologies has addressed these aspects in isolation rather than as a coupled cause-effect chain, this review summarizes evidence along an aging-risk-removal nexus and proposes a risk-based removal strategy that prioritizes the most hazardous aged and nano-sized fractions. We evaluate how aging can both facilitate capture and exacerbate operational risks in water treatment, and highlight integrated, multi-barrier strategies that couple pre-aggregation, physical separation, and risk reduction. By establishing an aging-risk-removal nexus, this review provides a risk-oriented perspective for identifying high-risk aged MP/NP fractions and guiding targeted removal strategies for risk reduction, beyond apparent removal efficiency, in aquatic systems. This aging-risk-removal nexus gives a useful basis for MP/NP management in both MP/NP research and governance.

As demand for non-sewered sanitation continues to increase globally, faecal sludge management (FSM) continues to have critical implications for public health and sustainable development. However, understanding of the life-cycle performance of alternative FSM technologies is lacking. Here, we address this gap and present a framework for combined life cycle assessment and cost analysis to systematically quantify the carbon footprint and economic viability of faecal sludge treatment plants (FSTP). We apply the framework to two case study FSTPs in Beijing (FSTP1 and FSTP2), which serve as representative examples of FSM in mega-cities in China and the world. These plants use different FSM technology and process different waste mixtures, with FSTP1 using traditional physicochemical processes to treat single-source faecal sludge and FSTP2 co-processing faecal sludge, food waste, and municipal sludge through anaerobic digestion, combined with biogas and crude oil recovery. Carbon emissions analysis shows that FSTP1 emits 54.7 ± 2.08 kg CO2-eq/t organic waste (OW), which is considerably lower than FSTP2's net emission of 70.5 ± 8.45 kg CO2-eq/t OW. This accounts for FSTP2's 43.6 % emission reduction from resource recovery, which partially offsets the plant's otherwise much higher carbon emissions. Transportation distance and grid GHG emission intensity are key factors that affect each plant's carbon footprint. Thus, emissions could be reduced through development of low-carbon faecal sludge treatment technologies and optimization of regional logistics and energy structures. Economic analysis shows that the life cycle costs for FSTP1 and FSTP2 are 79.7 million CNY (≈11.2 million USD)1 and 282 million CNY (≈39.7 million USD), respectively. Although FSTP2 requires a higher initial investment, its diversified revenue structure and stable treatment fees result in a higher operating income, shortening the investment payback period to just over 10 years, compared to the 14 years required by FSTP1. This indicates the greater economic feasibility of the synergistic treatment and resource utilization approach in the medium to long term. The research findings can inform optimized urban faecal sludge management strategies and selection or promotion of lower-carbon treatment technologies and circular economy models.

The strategic conversion of fermentation effluents from organic waste into microbial lipids for biofuel production has emerged as a key strategy for advancing sustainable development. However, inhibitory components in fermentation broths substantially impair the metabolism of oleaginous microbes, critically compromising bioconversion efficiency. Traditional pretreatment methods, such as chemical and enzymatic approaches, incur additional costs. Adaptive Laboratory Evolution (ALE) technology is based on the principle of directed evolution, precisely constructs biological stress environments and reshapes microbial metabolic networks to enhance strain tolerance and functionality. This enables the direct utilization of complex fermentation broths for lipid production. This paper first introduces the mechanism of selective pressure exerted by the ALE technique, and proposes strategies for nutrient supply and extreme environmental stress based on the physiological characteristics of strains. It then focuses on the technical principles of the ALE process, with a key discussion on the different evolutionary modes of ALE and their applicable scenarios. Building on this foundation, this review introduces novel integrative strategies bridging ALE and synthetic biology, employing precision metabolic engineering, genomic editing and machine learning to expand the application boundaries of ALE technology. Finally, the future development trends of ALE technology in the field of organic waste resource utilization are systematically explored in this review.