When typical triphenylmethane dyes (crystal violet) and phenazine dyes (saffron T) were used as the research objects, the biotoxicity of dye wastewater was investigated before and after treatment using the Fe⁰/H₂O₂ process through the analysis in growth indicators (growth rate and inhibition rate), photosynthetic indicators (chlorophyll a, chlorophyll b, and carotenoid content), protein content, polysaccharide content, and antioxidant enzyme activity systems (superoxide dismutase (SOD), catalase (CAT), and malondialdehyde (MDA)) of Chlorella vulgaris (C.vulgaris). The results showed that with the extension of reaction time, the growth rate of C.vulgaris gradually decreased and its inhibition rate increased. The growth of C.vulgaris cells was significantly inhibited in raw dye wastewater. Compared with raw dye wastewater, chlorophyll-A content of C.vulgaris was increased by 22.01% in the effluent wastewater after treatment, and the contents of chlorophyll-B and carotenoid were decreased by 12.97% and 16.02%, respectively. The contents of SOD and CAT were increased by 15.13% and 12.5%, respectively, while the content of MDA was decreased by 23.97%, respectively. The protein content of C.vulgaris in raw dye wastewater was low, while its content was high in the effluent wastewater after treatment. Compared with raw dye wastewater, the content of polysaccharide in the effluent wastewater exhibited a decreasing trend. According to the toxicity prediction of algae using EPI Suite software, the toxicity of the intermediate product of crystal violet and saffron T degradation to fish, water flea and green algae was significantly reduced. Therefore, the biotoxicity of dye wastewater could be effectively reduced in the Fe⁰/H₂O₂ system.

The persulfate-based advanced oxidation process demonstrates significant advantages in the removal of refractory organic pollutants. However, traditional activation methods are associated with high energy consumption and the potential generation of secondary pollution, which restricts the widespread application of this technology. Based on the photosensitive properties of dissolved organic matter (DOM) in secondary effluent, a practical self-activation peroxymonosulfate (PMS) reaction system using solar radiation was established. Systematic investigations were conducted on the effects of different persulfate types, initial pH conditions, and common inorganic anions on PMS decomposition efficiency, accompanied by comprehensive characterization of physicochemical properties and structural transformations in DOM before and after the reaction. The results indicated that the all fractions of secondary effluent could effectively activate PMS, with the hydrophilic (HI) fraction exhibiting the most efficient activation, achieving a PMS decomposition rate of up to 26.7% under neutral conditions. During the decomposition process, reactive oxidative species generated from PMS interacted with DOM, leading to the gradual degradation of its aromatic structures and a reduction in molecular weight. The intensity of fluorescent substances, such as humic-like compounds, significantly decreased, while the proportions of lignin, lipids, tannins, and other compounds had notable changes. These observations indicated that the DOM in secondary effluent achieved self-degradation through effective activation of PMS. Humic-like compounds and lignin in secondary effluent DOM served as the primary electron donors. Upon excitation by sunlight, they transferred photogenerated electrons to PMS, thereby activating it and triggering the self-degradation of DOM. The self-catalytic system of using the DOM in actual secondary effluent in this study without the need for external catalysts, avoiding high energy consumption and secondary pollution.

SiO₂@nZVI@Fe₃O₄ composites were successfully synthesized by liquid-phase reduction and stőber hydrolysis. The microstructures and physical phase compositions of SiO₂@nZVI@Fe₃O₄ were analyzed by SEM-EDS, TEM, XRD, FTIR, VSM, and XPS. The degradation performance of azo dyes was investigated by using SiO₂@nZVI@Fe₃O₄ as a non-homogeneous catalyst combined with H₂O₂to construct a Fenton-like system. The results showed that the SiO₂ coating improved the dispersion and oxidation resistance of nZVI@Fe₃O₄, and it was able to enhance the generation of Fe²⁺ and HO· in the Fenton-like reaction system. Under the conditions of 25℃, pH 3, H₂O₂ concentration of 15mmol/L, and material dosage of 0.6g/L, the removal efficiency of Congo red, Orange II and Acid Black 210 reached 99.68 %、98.14 % and 99.35 %. The composite material could still remove more than 79% of the three pollutants after recycling for three times, which has good stable catalytic performance. The removal of azo dyes by SiO₂@nZVI@Fe₃O₄ combined with Fenton-like system was mainly through the reduction of nZVI and the oxidation of HO·, as demonstrated by reactive oxygen species quenching experiment and UV-visible spectral analysis.

Fe-modified/unmodified Carex meyeriana Kunth biochars were prepared at 300, 500, and 700℃. The degradation efficiencies of rhodamine B (RhB) in water by peracetic acid (PAA) were compared. The effects of reaction conditions (PAA concentration, Fe-KBC700 dosage, RhB concentration, pH, H₂O₂ concentration, co-existing anion and fulvic acid) on 700℃ iron-modified biochar (Fe-KBC700) were studied. The dominant active species, activation mechanism and degradation pathways of RhB were analyzed. High pyrolysis temperature and the introduction of Fe were beneficial to the improvement of biochars activation properties. Fe-KBC700/PAA system degraded 99.8% of RhB within 30min. Higher PAA concentration, Fe-KBC700dosage and lower RhB concentration were conducive to RhB degradation, while alkaline conditions and higher co-existing H₂O₂ concentration inhibit the reaction. Cl^-, SO₄^2-, and NO₃^- hardly affect the degradation of RhB, while HCO₃^- and fulvic acid could inhibit the reaction. The degradation of RhB was mainly due to the non-radical pathway. Singlet oxygen, electron transfer process and high-valent iron were detected in the reaction. The oxygen-containing functional groups and defects of Fe-KBC700 were the key reaction sites, and two degradation pathways of RhB were inferred. In addition, Fe-KBC700 could degrade 75.4% of RhB after 5 cycles. This study could provide a reference for the optimization of catalytic performance of biochars and the mechanism of activation of PAA by iron-modified biochar.

Multi-metal catalysts Mn-Cu-Co-Ce/TiO₂, Mn-Ce-Co/TiO₂, and Mn-Ce-Cu/TiO₂ were synthesized via the impregnation method. Among them, Mn-Cu-Co-Ce/TiO₂ was characterized before and after the reaction using BET, XPS, O₂-TPD, FT-IR, SEM-EDS, and XRD techniques. The catalytic performance of the catalysts for isopropanol degradation in a non-thermal plasma (NTP) synergistic system was investigated. The effects of initial concentration, gas flow rate, oxygen content, and catalyst water content on degradation efficiency were systematically analyzed. Organic byproducts generated during the degradation process were detected using gas chromatography-mass spectrometry (GC-MS), and the degradation mechanism under NTP conditions was explored. The results indicated that the NTP-assisted multi-metal catalyst system exhibited over 54% improvement in degradation efficiency compared to NTP alone, achieving a removal rate of 90.22%. CO₂ selectivity also increased by approximately 34%, reaching 63.97%. In the synergistic system, degradation efficiency was negatively correlated with initial concentration, gas flow rate, and catalyst water content, while it was positively correlated with voltage. Moreover, the formation of byproducts such as O₃was effectively suppressed. The degradation path of isopropyl alcohol may involve multiple aspects, including direct oxidation mineralization under the guidance of NTP, intermediate oxidation process, and deep redox reactions.

Solid phase extraction (SPE) is extensively utilized for the extraction of dissolved organic matter (DOM); nevertheless, the efficiency of SPE under specific conditions (employing formic acid as the acidifier, hydrophilic-lipophilic balance (HLB) as the sorbents, and methanol as the elution solvent) remains unclear. In this study, 13 refuse leachate samples, 10 effluent samples after leachate treatment, and 14 surrounding groundwater samples from 13 landfills were collected. The excitation and emission matrix was employed to analyze the stock solution, eluent, and permeate before and after SPE, enabling the evaluation of DOM enrichment and loss during the extraction process. The results indicated that this SPE method could effectively extract fulvic acids with short emission wavelengths from leachate and aromatic proteins from treated effluent and groundwater. However, but it exhibited low efficiency in recovering large humic acid molecules. This inefficiency might be attributed to the incapability of formic acid to effectively protonate these components. Parallel factor analysis indicated that the method preferentially extracted structurally simple tryptophan-like proteins, while its performance for humic acids was restricted. The SPE method involving formic acid acidification, HLB cartridge adsorption, and methanol elution effectively separates and extracts structurally simple and hydrophilic DOM. These results provide a valuable reference for further elucidating the characteristics of low-molecular-weight, hydrophilic chlorinated DOM.

A continuous baffle flow electrocatalytic oxidation device, using porous Ti₄O₇ anodes prepared through vacuum plasm spraying technology, was developed to achieve the effective degradation of sulfamethoxazole (SMX) in wastewater. The effects of operation conditions on SMX degradation efficiency were examined, the energy consumption and the stability of the system were assessed in the treatment of actual wastewater. The possible electrocatalytic degradation mechanism of SMX was also proposed. SMX removal efficiency, energy consumption, mineralization efficiency and mineralization current efficiency could reach at 82.0%, 13.1kWh/m³, 34.2% and 0.7%, respectively, at the initial SMX concentration of 10mg/L, Na₂SO₄ concentration of 5mmol/L, current density of 5mA/cm², and solution velocity of 27mL/min. The primary degradation mechanism of SMX was indirect oxidation, and the contribution efficiencies of ·OH and were 76.2% and 5.8%, respectively. The dominant degradation pathways were hydroxylation, N-S bond cleavage, oxidation and coupling reactions. The device exhibited good stability during the long-term treatment of both experimental and actual wastewaters, with SMX degradation efficiency, TOC removal efficiency, and COD removal efficiency in actual wastewater reaching 100%, 19.8%, and 72.2%, respectively. The electrocatalytic oxidation device effectively degraded SMX, and it also reduced the toxicity. Therefore, the continuous baffled flow electrocatalytic oxidation device based on the porous Ti₄O₇ electrode can effectively eliminate SMX from wastewater.

Surface water samples were collected from two municipally monitored sections of the Tuhai River in Liaocheng—Li Fengtao and Lao Nanzhen—and analyzed using a combination of spectroscopic techniques, including ultraviolet-visible (UV-Vis) absorption and three-dimensional excitation-emission matrix (EEM) fluorescence spectroscopy, supplemented by ultrafiltration fractionation and fluorescence-quenching experiments to comprehensively characterize dissolved organic matter (DOM). The study investigated seasonal variations in DOM composition across three molecular weight fractions (<0.7μm, 0.7μm~1kDa, and<1kDa) and explored the underlying mechanisms of DOM-Cu²⁺ complexation. The specific ultraviolet absorbance at 254nm (SUVA254) was significantly higher at Li Fengtao (0.33 ± 0.01) than at Lao Nanzhen (0.30 ± 0.01) (P<0.05), suggesting a higher proportion of smaller, non-aromatic molecules at the latter site. Parallel factor analysis (PARAFAC) of EEM data identified five fluorescent components, including three humic-like (C1, C2, C4) and two protein-like (C3, C5) substances, with humic-like constituents dominating at both locations. Total fluorescence intensity (F_max) was higher at Lao Nanzhen, and dissolved organic carbon (DOC) was primarily concentrated in the <1kDa fraction at both sites. Two-dimensional correlation spectroscopy (2D-COS) analysis demonstrated that humic-like components preferentially bound to Cu²⁺ in the unfractionated DOM samples from both locations. However, after ultrafiltration fractionation, the binding sequence shifted, with protein-like components becoming the dominant Cu²⁺-binding constituents. Furthermore, high-molecular-weight fractions (excluding C1 and C4) from both sites exhibited relatively strong metal-binding capacities, as evidenced by their conditional stability constants (logK_Cu:(3.08 ± 0.08) to (3.62 ± 0.02)).

In order to understand the current research status of fingerprinting technology and clarify its application and prospects in the field of solid waste, the Web of Science (WOS) core database: Science Citation Index Expanded (SCI-Expanded) was relied upon to retrieve and analyze relevant literature from 2010 to 2024. It was found that the number of publications indicates that fingerprinting technology still maintains a high level of research interest. The subject clustering analysis shows that its application is extensive and its research interest in the environmental field has also been high in recent years. Keyword clustering reveals that the research hotspots are concentrated in four aspects: Recognition, ChemoInformatics, Deep learning, and Model. Keyword co-occurrence analysis of literature in the field of solid waste shows that there are few studies on the use of fingerprinting technology for solid waste management, mainly focusing on the post-processing stage. Through literature research, the data acquisition technology, feature extraction technology, and feature presentation forms of fingerprinting were summarized, and the possibility of applying emerging technologies in the field of solid waste and future development prospects were proposed.

To explore the enhancement strategies for the methane production efficiency of anaerobic co-digestion systems by exogenous compound enzymes, corn stover and food waste were adopted as the mixed substrates. Subsequently, the combination and concentration of exogenous compound enzymes were optimized through batch experiments and the response surface methodology. In the single-factor experiment on lignin, the component and concentration range of the compound enzymes were screened. Moreover, 20groups of experiments with the concentrations of laccase, endo-β-1,4-glucanase and xylanase as variables were designed by means of the response surface methodology, and with the methane production promotion rate as the optimization objective. Based on the experimental data, a model was successfully established and variance analysis was carried out. The results showed that response surface analysis identified enzyme combinations within the ranges of laccase (1.5~4.0U/mL), xylanase (12~20U/mL) and endo-β-1,4-glucanase (50~85U/mL), which could achieve a high methane production promotion rate, was finally determined as the appropriate component of the compound enzyme. The continuous flow test validated the efficacy of the composite enzyme, indicating that the addition of the compound enzyme promoted the proliferation of hydrolases and aceticlastic methanogens, released lignin, cellulase and anaerobic digestion enzymes with higher activities, and thus increased the methane production rate of the anaerobic co-digestion system by 19.5%.