Semi-coking wastewater (SCWW) contains toxic compounds that threaten both human health and ecosystem integrity. In this study, an anaerobic ammonium oxidation (anammox)-based simultaneous partial nitrification, anammox, and denitrification (SNAD) process, enhanced with a novel polyvinyl alcohol/phytic acid/iron (PVA/PA/Fe) hydrogel carrier, was evaluated for treating actual SCWW. During long-term operation, the system achieved removal efficiencies of 90.8 % for ammonium nitrogen (NH4+-N) and 91.4 % for chemical oxygen demand (COD) in SCWW. The PVA/PA/Fe carrier facilitated sludge aggregation, enhanced extracellular polymeric substance secretion, and successfully enriched key functional microbes, encompassing anammox bacterium Candidatus Brocadia and phenol-degrading denitrifier Ottowia. Acute toxicity assays and nitrogen removal inhibition tests identified phenyl cyanate as a major toxicant in SCWW. Molecular docking confirmed its strong binding affinity for critical enzymes such as hydroxylamine oxidoreductase (Hao) and nitric oxide reductase (Nor). Adsorption experiments and density functional theory (DFT) calculations revealed that the PVA/PA/Fe effectively adsorbed phenyl cyanate via Fe-mediated coordination, with an adsorption capacity of 10.59 mg g-1. This capacity was sixfold greater than that of the unmodified carrier, substantially lowering the environmental concentration of phenyl cyanate and alleviating its inhibitory effect. Collectively, these findings provide a viable carrier-enhanced strategy for the biological treatment of SCWW.

The use of extracellular polymeric substances (EPS) stripped from sludge as a supplementary carbon source represents a novel method for enhancing nitrogen removal in low-carbon wastewater. This approach aims to leverage EPS while preserving the sludge metabolic activity. However, the effect of the EPS stripping degree on sludge metabolic activity remains poorly understood. In this study, EPS were progressively removed from activated sludge via ultrasonic centrifugation, and the resulting changes in sludge metabolic activity and settleability were systematically evaluated. The results demonstrate that key metabolic indicators, such as the specific oxygen uptake rate (SOUR), ammonia utilization rate (AUR), nitrogen utilization rate (NUR), and phosphorus release rate (PRR), initially increased and then decreased with increasing EPS removal. Optimal activity rates were observed at a 45

To address the challenges of Ag(I) recovery and sulfonamide antibiotics removal from water, we developed a water treatment system integrating selective Ag(I) adsorption with efficient degradation of sulfonamide antibiotics. In this system, an S,N-dual-adsorption-site MoS2/polypyrrole-methane carbon material (MC) was prepared, exhibiting selective Ag(I) capture with an adsorption capacity up to 674.1 mg/g. Subsequent in situ reduction at 80 °C yielded a composite catalyst (MCA) loaded with Ag nanoparticles (Ag NPs). The MCA/H2O2 system degrades sulfamethoxazole (SMX) through direct electron transfer (DET) from activated H2O2 synergized with a 1O2 non-radical pathway, achieving 98% removal in 60 min with a rate constant (k) 7.1 and 4.6 times that of MoS2 and MC, respectively, and exhibiting high efficacy for other sulfonamides degradation. Density functional theory (DFT) results reveal that Ag NPs incorporated into MCA facilitate interfacial charge transfer, lower the activation energy barrier for 1O2 generation, thus enabling direct activation of dissolved oxygen to 1O2. Continuous-flow experiments using sponge carriers validated the practical application potential of the MCA system. This work achieves a triple synergy of precious metal recovery, resource recycling, and efficient pollutant degradation, providing a new strategy for resource reclamation from Ag(I)-containing wastewater and advanced treatment of sulfonamide antibiotics in water.

Solar evaporation technology is a core path to achieving sustainable water purification. Researchers are developing advanced solar evaporators (SE) to improve evaporation performance by promoting solar energy absorption and reducing salt crystals on the evaporation surface. This work comprehensively reviewed the effects of macro and microchannel structures on SE performance and summarizes the application of 3D printing in SE construction. The 3D printing materials for SE include carbon, polymer hydrogels, ceramic precursors and composite materials. The selection and synthesis of materials should be carried out with the improvement of printability and evaporation performance. By adjusting the rheological properties, crosslinking mechanism and printing conditions, the printability of SE materials can be improved. The application of 3D printing to enhance solar-driven evaporation technology has problems and challenges in printing accuracy and resolution limitations, material properties, and large-scale production costs. 3D printing technology can significantly improve the sustainability of solar evaporation systems by prioritizing renewable materials, e.g., biochar and polylactic acid, developing recyclable thermoplastic processes and low-temperature curing technologies. It is proposed to develop 3D printing technology based on phase change materials, reasonably improve printability, crystal classification and adapt to industrial wastewater treatment applications. Future research needs to focus on the development of optical-thermal-electric coupling hybrid systems, and expand to hybrid industrial wastewater treatment scenarios to promote the industrialization of solar-driven evaporation technology.

Membrane fouling is a major challenge for the long-term and stable operation of membrane bioreactors (MBRs). This study systematically investigated the membrane fouling behaviors and mechanisms in three typical MBR systems: a denitrifying phosphorus removal MBR (DPR-AxMBR), an aerobic phosphorus removal MBR (AeMBR), and a denitrifying nitrogen removal MBR (DNMBR). The analysis focused on sludge properties, extracellular polymeric substances (EPS), and microbial community structure to elucidate the influence of different biological metabolic pathways on fouling. The results demonstrated that the DPR-AxMBR system exhibited superior fouling control. The time to reach the critical transmembrane pressure was extended to 137 h, which was significantly longer than that of AeMBR (29 h) and DNMBR (19 h). The DNMBR system experienced the most severe membrane fouling, primarily due to poor sludge settleability, a high accumulation of EPS in the cake layer (59.44 mg/ L), and a significant enrichment of fouling-related microbial communities such as Chloroflexi and Acidobacteria. In contrast, the DPR-AxMBR system not only achieved efficient simultaneous nitrogen and phosphorus removal but also significantly mitigated membrane fouling. This was mainly attributed to its relatively low EPS content in the cake layer and the dominance of functional genera like Dechloromonas. This study elucidates the mechanisms of membrane fouling in MBRs from the perspective of the interplay between metabolic pathways and sludge characteristics, providing critical theoretical support for mitigating membrane fouling through process optimization.

The co-existence of metal ions and dissolved organic matter (DOM) is a common characteristic of industrial wastewater. Considering this phenomenon, this study developed an advanced oxidation system that leveraged metal-DOM complexation to significantly enhance the activation of peroxymonosulfate (PMS) by photoexcited DOM under solar irradiation. Compared with the system without metal ions, the Fe3+/DOM/PMS/solar system exhibited substantial performance improvements, with the efficiencies of PMS decomposition, UV254 removal, and DOM mineralization increasing by factors of 4.72, 4.56, and 12.94, respectively, reaching final efficiencies of 91.3%, 87.9%, and 68.05%, respectively. Mechanistic investigations revealed that metastable triplet-state DOM (3DOM*) served as a key intermediate, transferring electrons to PMS to predominantly generate 1O2, along with smaller amounts of center dot OH and SO4 center dot-. X-ray absorption fine structure analysis confirmed the formation of Fe-O coordination bonds, which broadened DOM light absorption, promoted photoinduced electron generation, and facilitated a Fe3+/Fe2+ redox cycle that provided an additional activation pathway for PMS. At the molecular level, FT-ICR MS analysis demonstrated that the Fe3+-enhanced system induced extensive transformations across diverse elemental compositions and redox states, effectively converting DOM into lower-molecular-weight, more saturated, and less oxidized fragments. Machine learning combined with SHAP analysis further identified m/z, the nominal oxidation state of carbon, and the S/C ratio as key molecular descriptors determining DOM reactivity under Fe3+-enhanced conditions. Chloride effects and real industrial wastewater validation show the process remains effective in complex water matrices. This work elucidates metal-DOM complexation-enhanced PMS activation and provides a waste-treats-waste strategy for wastewater purification.

This study presents a sunlight-driven synergistic activation of ferrate (Fe(VI)) and periodate (PI) (Fe(VI)/PI-SL) for the ultrafast degradation of recalcitrant emerging contaminants in real complex wastewater matrices, leveraging dissolved organic matter (DOM) as a catalytic promoter instead of a scavenger. The Fe(VI)/PI-SL system was evaluated in real secondary effluents using sulfamethoxazole (SMX) as a model contaminant, with integrated performance evaluation, reactive oxidizing species (ROS) identification, kinetic analysis, and molecular-level DOM characterization. The process achieved over 95 % SMX degradation only within 120 s, with a rate constant of 0.0723 s-1 that surpasses most conventional advanced oxidation processes. Molecular-level analysis revealed that reduced, aromatic, and electron-rich DOM fractions facilitate Fe(III) reduction via ligand-to-metal charge transfer (LMCT), sustaining a catalytic cycle that predominantly generates hydroxyl radicals (center dot OH). Notably, the treatment avoids the formation of toxic iodinated byproducts, reduces overall effluent toxicity, and demonstrates broad-spectrum efficacy against diverse emerging contaminants. These findings establish Fe(VI)/PI-SL as a green, solar-powered strategy that innovatively transforms a ubiquitous matrix component into a catalytic asset, providing a highly effective and environmentally benign route for advanced wastewater remediation.

To simultaneously address ammonia emission during paste backfill application and strength degradation caused by poor stability of fly ash, this study designed an experimental protocol integrating flue gas stripping of fly ash slurry and subsequent preparation of backfill materials. The effects of free CaO(f-CaO) content, solid-liquid ratio (S/L), gas-liquid ratio (G/L), and alkali dosage on ammonia removal and CO2 sequestration efficiency were systematically investigated during simulated flue gas stripping. Microstructural and mineralogical evolution of fly ash before and after treatment was characterized via scanning electron microscopy (SEM) and X-ray diffraction (XRD). The feasibility of utilizing stripped slurry for paste backfill preparation was further evaluated. Results demonstrated that under optimal conditions (S/L=0.2 kg/L, G/L=800 L/m3, alkali dosage=0.5%, 30-min stripping), CO2 in flue gas was effectively mineralized by f-CaO, achieving over 80% of theoretical CO2 sequestration capacity across three fly ash types, with a maximum sequestration of 90.52 g/kg. SEM and XRD analyses revealed that Ca(OH)2 was converted to CaCO3 during stripping, predominantly forming crystalline aggregates adhered to fly ash particles. Although ammonia removal efficiency reached only 30%, the pH of fly ash slurry decreased to neutrality due to CO2 mineralization, significantly suppressing ammonia release (about 70% reduction) during curing of backfill materials. The 28-day compressive strength of backfill specimens prepared from treated slurry reached 6.62, 7.91 and 8.34 MPa, exhibiting substantial improvements compared to untreated controls. While rheological properties slightly declined, all pastes met engineering specifications. This integrated flue gas stripping-carbonation activation strategy provides a systematic solution for large-scale utilization of industrial solid wastes (e.g., ammonia-rich high-f-CaO fly ash), enabling dual benefits of pollutant control and resource recovery while advancing sustainable practices in coal-fired power and chemical industries.

Uranium-bearing mining wastewaters often contain bicarbonate, calcium, and magnesium, which complicate rapid treatment by stabilizing aqueous uranyl complexes and altering precipitation pathways. This study evaluated nucleation-induced crystallization (NICP) as a continuous-flow process for uranium removal from three real mining wastewaters with distinct Ca/Mg compositions. Under optimized NaOH dosing, uranium removal exceeded 97.7% at a hydraulic retention time of 6 min, while continuous operation over 100 h remained stable and uranium leaching from pelletized products stayed below 5 mu g & sdot;L- 1. In contrast, carbonate-dominated conditions suppressed uranium removal to below 22% despite effective Ca precipitation. Speciation analysis indicated that hydroxide-rich conditions shifted U(VI) toward UO2(OH)3- , which was more readily transferred to growing Ca/Mg-bearing solids, whereas carbonate-rich conditions stabilized soluble UO2(CO3)34- and hindered solid-phase transfer. Magnesium further improved process performance and product stability by promoting uranium capture and reducing uranium release from the separated pellets. These results show that NICP is a rapid and robust treatment option for carbonate-rich uranium-bearing mining wastewaters.

Sediment re-suspension is a major source of overflow pollution in combined sewer systems. Based on the sediment stratification theory, this study constructed a pilot-scale sewage pipeline system and proposed a precise prediction method for sediment scour initiation and overflow pollution. Sediment stratification governs pollutant behavior throughout the "scouring-release-transport" cycle: loose surface layers are easily scoured, with fine particles and high-concentration pollutants rapidly released and widely dispersed by flow, whereas dense middle-to-bottom layers exhibit strong scour resistance and low pollutant background levels, causing released particles to readily settle with limited dispersal capacity. Under simulated heavy rainfall conditions (shear stress of 5.42 N/m²), the average erosion rate of surface sediments reached 3000 mg/s, accompanied by high chemical oxygen demand, total nitrogen, and total phosphorus release fluxes, constituting the primary risk source for overflow pollution. By contrast, the erosion rates in the middle and bottom layers were only 450 mg/s and 80 mg/s, respectively, indicating significantly reduced pollution contributions. Based on these mechanisms, a coupled kinetic model was developed for the stratified scouring and transport of sewer sediments. By integrating hydrodynamics, scouring, and transport modules, the model calculates the hydraulic conditions, stratified erosion, pollutant release, and pollutant migration processes. This study systematically reveals the mechanisms by which sediment transport affects water quality under different rainfall conditions, providing a reliable model and quantitative method for the accurate prediction of pollution from drainage pipeline overflows.

In this study, catalytic ceramic membranes (CMs) were modified with N-doped biochar (N-C-CM) and Fe/N codoped biochar (Fe/N-C-CM) to mitigate membrane fouling and improve pollutant removal during advanced wastewater treatment. The developed catalytic CM filtration system combined peroxymonosulfate activation with filtration, enabling in situ oxidation for enhanced organic removal and membrane self-cleaning. Compared with pristine CMs and N-C-CM, Fe/N-C-CM demonstrated superior pollutant removal efficiency and anti-fouling performance. Under optimal conditions, Fe/N-C-CM achieved significantly higher removal efficiencies for the model foulants, namely sodium alginate (SA) and bovine serum albumin (BSA). Specifically, Fe/N-C-CM removed 55.85% of SA and 83.13% of BSA. In contrast, N-C-CM removed 23.71% of SA and 54.04% of BSA. Additionally, Fe/N-C-CM suppressed pore blockage and cake layer formation, thereby effectively mitigating both reversible and irreversible fouling. In the N-C-CM system, the primary reactive oxygen species were SO4-center dot/center dot OH. In Fe/N-C-CM, the dominant reactive species shifted to singlet oxygen (1O2). The highly selective 1O2-mediated reaction facilitated efficient pollutant mineralization. To assess its practical feasibility, Fe/N-C-CM was used to treat secondary effluent from a wastewater treatment plant. Under optimal conditions, Fe/N-C-CM achieved 68.45% total organic carbon removal and reduced the turbidity of the treated effluent to undetectable levels. Notably, Fe/N-C-CM maintained high flux and fouling resistance over multiple cycles, indicating robust stability and effective self-cleaning. This study provides a sustainable approach combining advanced oxidation with membrane technology for efficient wastewater reclamation.

Organic removal from reverse osmosis concentrates (ROC) via oxidation remains challenging due to the high salinity. In this study, a continuous coagulant and alkali dosing synchronous ozonation coagulation (CDSOC) process consisting of two stages was established for actual ROC treatment. In the rapid stirring stage, continuous dosing of coagulant and alkali prolonged the formation of hydrolyzed Al species, which were transformed from monomeric Ala, medium-polymeric Alb to high-polymeric and colloidal Alc, thereby forming primary flocs with smaller size, rougher surface and larger specific surface area. The flocs formed in the CDSOC effectively captured a greater amount of lignin-like CHOS and CHNOS organics, and more coagulable organics were detected in the flocs. In the slow stirring stage, the integration of ozonation and coagulation introduced more active surface hydroxyl groups and adsorbed water onto the flocs, thereby enhancing organic binding and enabling Al(III)Tet. to catalyze ozone decomposition for enhanced hydroxyl (•OH) generation. Notably, intermediate organics with oxygen-containing groups, particularly carboxyl groups, were sustainably captured by flocs in the CDSOC process. The CDSOC process achieved 69.4% DOC removal efficiency for the treatment of actual ROC with coagulation accounting for 71.5% organic removal. FT-ICR MS results demonstrated that the CDSOC process effectively removed sulfur-containing fractions. A larger proportion of low-coagulable organics were effectively eliminated through coagulation in the CDSOC process, indicating a significant improvement in organic removal. This study provides an additional separation pathway for organic removal in a high-salinity environment.

In traditional anaerobic digestion (AD) systems for food waste (FW) without pretreatment, the organic loading rate (OLR) is often restricted to a low level due to acidification inhibition. Fenton sludge (FS) and biochar prepared from Fenton sludge (BC-FS) were used to enhance AD performance of FW in this study. The results showed that the iron in FS primarily exists as FeOOH, the iron in the BC-FS was present as Fe3O4. Adding FS and BC-FS to semi-continuous reactors for AD of FW increased the OLR by 80% and 180%, respectively, and increased the biogas yield per unit of organic matter. Both FS and BC-FS enhanced the enzyme activity of anaerobic microorganisms, significantly increasing dehydrogenase and coenzyme F420 activity. Furthermore, FS and BC-FS both promoted the removal of proteins and volatile fatty acids (VFAs), particularly the rapid conversion of propionic and butyric acids. Additionally, FS and BC-FS altered the proportions of proteins and polysaccharide in extracellular polymeric substances (EPS) of anaerobic granular sludge, improving the electrochemical properties of EPS and enhancing inter-microbial electron transfer capabilities. FS and BC-FS affected the microbial population structure of the reactors, the DIET functional bacteria (Chloroflexota), iron-reducing bacteria (Desulfobacterota), and Methanosaeta were enriched, thus the AD performance of FW was improved.

The coexistence of nitrogen, phosphorus, and cadmium in wastewater poses a compound hazardous-contaminant challenge, because heavy metals can impair biological nutrient removal while remaining persistent and bioaccumulative. In this study, a cadmium-tolerant strain, Pseudomonas nitroreducens Z22, was isolated and evaluated for simultaneous nutrient and Cd(II) removal under aerobic conditions. Without Cd(II) stress, Z22 achieved high removal efficiencies of 96.93% for NO3--N and 84.58% for PO43--P. Under Cd(II) exposure, Z22 tolerated concentrations up to 50 mg/L and showed a distinctive ”inhibition–resurgence–inhibition” pattern in phosphorus removal. Genomic and metabolic analyses demonstrated the coexistence of a complete heterotrophic nitrification–aerobic denitrification pathway and polyphosphate metabolism. Mechanistically, Cd(II) removal was mainly associated with intracellular sequestration and extracellular biomineralization, in which polyphosphate hydrolysis released phosphate that promoted the formation of cadmium phosphate precipitates. This response indicates a survival-driven energy allocation strategy, where limited metabolic resources are shifted from nutrient removal and biomass synthesis toward heavy-metal detoxification under Cd stress. These findings reveal how phosphorus metabolism can be functionally redirected to immobilize cadmium, providing mechanistic insight into microbial treatment of wastewater co-contaminated with nutrients and hazardous metals.

Hydrophilic low-molecular-weight (LMW) organic matter represents a recalcitrant fraction in drinking water treatment, often limiting the efficacy of conventional coagulation. This study explores a novel hydraulic control strategy within the continuous dosing coagulation (CDC) process to overcome this bottleneck, aiming to enhance energy efficiency while elucidating the mechanism of active site generation. Results demonstrated that intensive mixing (Re > 6000, G > 85 s(-1)) during the continuous dosing stage was the critical factor, enhancing LMW organic removal by 15.5% while maintaining low residual turbidity (< 0.3 NTU) and aluminum (< 0.2 mg/L). Notably, the subsequent slow mixing duration had minimal impact, allowing for a significantly shortened process footprint. Mechanistically, we elucidated a shear-induced dual-pathway activation model that governs floc reactivity. Contrary to the traditional view that high shear leads to deactivation via crystallization, our findings revealed a dynamic equilibrium: although intensive shear induced partial crystallization, it concurrently drove (1) physical fragmentation, exposing encapsulated internal binding sites, and (2) chemical structural depolymerization, dissociating Al-OH-Al bridges to generate highly reactive terminal Al-OH2 sites. Consequently, the net positive generation of active sites outweighed the adverse effects of crystallization. This work provides fundamental insights into utilizing hydrodynamic shear as a precise tool to regulate floc surface chemistry, offering an energy-efficient solution for removing refractory organics.

Bio-trickling filters are commonly applied for the on-site treatment of decentralized rural sewage under fluctuating influent loads. However, the existence of oligotrophic layers with organic content below 50 mg/L constrains further improvements in treatment efficiency. To overcome the limitations of oligotrophic layers, biomass density and metabolic activity were enhanced by leveraging microbial adaptive responses to oxidative stress. This regulation strategy was implemented by incorporating a ventilation interlayer, achieving an 11.3% increase in total nitrogen removal efficiency. Under fluctuating influent conditions, denitrification was significantly enhanced, accompanied by a 3.4% increase in the abundance of denitrifying bacteria (DNB). Simultaneously, the concentrations of extracellular polymeric substances (EPS) increased under oxidative stress, thereby reinforcing biofilm integrity and enhancing interspecies mass transfer within the microbial community. Heterotrophic bacteria and algae utilized EPS as a medium for metabolite exchange, providing supplemental substrates for DNB in oligotrophic layers, thereby enhancing their growth and denitrification efficiency. Biological interactions were regulated by microbial oxidative stress, primarily manifested as enhanced metabolic activity, including carbon metabolism, mass transfer, and quorum sensing. The microbial response to oxidative stress collectively mitigated the adverse effects of loading fluctuations on treatment performance. This study provides a theoretical foundation for enhancing the treatment efficiency and stability of decentralized rural sewage treatment systems.

Colloidal manganese dioxide (cMnO(2)) is an effective activator of peroxymonosulfate (PMS) for degrading organic micropollutants. However, its performance is often limited by the instability of manganese valence states during PMS activation. To address this, we introduced Fe(III) into the cMnO(2)/PMS system, developing a novel and highly efficient Fe(III)-cMnO(2)/PMS advanced oxidation process. This system demonstrates exceptional catalytic activity, achieving 90.44 % degradation of sulfamethoxazole (SMX) within 30 mins with a rate constant 2.74 times higher than that of the cMnO(2)/PMS system, alongside significant mineralization. Its performance remains robust (>80 % efficiency) across a wide pH range (3.0-7.0). Mechanistic studies reveal that Fe(III) plays a dual synergistic role: it participates in a coupled Mn(IV)/Mn(III)/Mn(II) and Fe(III)/Fe(II) redox cycle that continuously regenerates reactive species (primarily center dot OH and center dot SO4- , with contributions from O-1(2) and high-valent iron), while simultaneously stabilizing the cMnO(2) colloid against deactivation. The system exhibits remarkable resistance to common water matrix components and maintains high efficiency in various real water samples. This work presents a simple yet effective strategy to enhance PMS-based oxidation, offering strong potential for the practical treatment of refractory organic pollutants in complex aquatic environments.

Heterogeneous catalytic ozonation, an efficient and promising technology, is often hindered by the resource-intensive nature of complicated catalyst preparation. This challenge is particularly acute in treating industrial wastewater, which faces the twin challenges of salt scaling and salt-inhibited oxidation. Herein, we propose a transformative hardness-to-catalyst strategy to achieve water softening and catalytic ozonation, termed the in situ crystallization-catalyzed ozonation process (ICCOP). Through the minimalist crystallization of inherent calcium into CaCO3, organics degradation exhibited significantly accelerated reaction kinetics, as the ICCOP improved O3 utilization efficiency and enhanced electron transfer. Surface atomic oxygen (*O) was identified as the dominant reactive oxygen species, with Ca atoms on the (1 0 4) plane of CaCO3 as the active sites. Practically, the ICCOP yielded effective decontamination of intricate fracturing flowback wastewater (FFW), achieving enhanced organics and Ca removal within a unitary reactor. Life cycle assessment (LCA) quantifiably demonstrates that the ICCOP markedly reduced CO2 emissions and environmental impact, owing to significant savings in chemicals and electricity, underscoring its strong sustainability advantages. This work deciphers a previously uncharted mechanistic role of Ca crystallization in catalyzing nonradical ozonation for enhanced organics degradation. Crucially, ICCOP emerges as a paradigm-shifting technology for waste-to-resource conversion, pioneering sustainable water remediation.

In this study, a novel internal recycled rotating cathodic electrochemical softening (IRRCES) system was developed to enhance Ca2+ removal from oilfield produced water containing amino trimethylene phosphonic acid (ATMP) scale inhibitors. The IRRCES system was a membrane-based divided electrolytic cell. During operation, oilfield produced water first flowed into the cathode chamber with a rotating cathode for maximize utilization of HCO3-in the raw water. Cathode rotation improved OH-diffusion, promoted homogenous CaCO3 crystallization, and increased crystal size in the cathode chamber, facilitating the following solid-liquid separation. After separation in the sedimentation tank, wastewater then entered the anode chamber for enhanced decomplexation between Ca2+ and ATMP. Ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-Q-TOF-MS) analysis confirmed Ca-ATMP degradation via C-P bond cleavage. Extended X-ray absorption fine structure (EXAFS) analysis revealed a reduction in Ca-O bonds within the anode chamber. The decomplexed intermediates then returned to the cathode chamber for crystallization. Elemental, morphological and lattice analyses of the precipitates verified the involvement of ATMP intermediates during Ca crystallization in the cathode chamber. CP2K calculations further indicated that ATMP intermediates co-precipitated via Ca-O covalent and hydrogen bonding with CaCO3. According to the above mechanism, the IRRCES system achieved around 90% Ca2+ removal efficiency, with a precipitation rate of 1545.6 gCaCO3/m2 & sdot;h for actual oilfield produced water containing ATMP with 1416 mg/L Ca2+, which significantly outperformed conventional electrochemical softening processes. The treated water from the IRRCES system was directly used to prepare guar gum fracturing fluid in oilfields. Overall, the IRRCES system provides a new approach for advancing the electrochemical softening of wastewater containing scale inhibitors.