Radioactive Wastewater Treatment Research Articles

Adsorption behavior and mechanism of U(VI) onto phytic Acid-modified Biochar/MoS2 heterojunction materials

Using a low-cost, pollution-free and efficient adsorbents to adsorb uranium in radioactive wastewater is of great significance to protect the environment. In this study, bamboo powder-derived biomass charcoal (BDC) was first composited with MoS2, and then the composites were surface-modified with phytic acid to obtain BDC/MoS2-PO4. The microstructure of the adsorbents was analyzed by various characterization techniques. The adsorption kinetics results showed that the U(VI) adsorption by BDC/MoS2-PO4 was more in line with the pseudo-second-order kinetic model, suggesting that the process is mainly chemical adsorption. The adsorption isotherm model confirmed that the U(VI) adsorption by BDC/MoS2-PO4 conformed to the Langmuir isotherm model, which was mainly surface monolayer adsorption with a maximum adsorption capacity of 161.29 mg/g. Furthermore, the adsorption performance of the adsorbent for U(VI) was significantly enhanced after H2 plasma treatment (204.08 mg/g), indicating that the increase in sulfur vacancies favors the U(VI) adsorption. The EPR, XPS and FT-IR results suggested that the interaction mechanism could be explained in that the S vacancies, S, C-O and P-O of the BDC/MoS2-PO4 were bonded to [O = U = O]2+ in the solution. This study provides a theoretical and experimental basis for the design and synthesis of biochar-based materials, and also provides a reference for radioactive wastewater treatment.

Graphene oxide/chitosan/potassium copper hexacyanoferrate(II) composite aerogel for efficient removal of cesium

Efficient removal of 137Cs from various radioactive wastewater and contaminated environment is much meaningful for nuclear energy sustainable development and public health. Herein we used chitosan (CS) to induce the self-assembly of graphene oxide (GO) into a hydrogel (GO/CS) possessing a three-dimensional macroporous structure and produced a type of ternary composite hydrogel/aerogel named GO/CS/Cu-PBA by in situ growing potassium copper hexacyanoferrate(II) (Cu-PBA) nanoparticles onto the GO/CS via simple leaching. The adsorption behaviors of Cs+ by GO, Cu-PBA, and GO/CS/Cu-PBA in various matrice was systematically studied and compared. It was found that the GO/CS/Cu-PBA exhibited satisfactory sorption capacity for Cs+ (64.7 mg/g) and ultrafast kinetics. In addition, a fixed-bed column system could be employed for the cleanup of Cs+ from contaminated groundwater. Further FT-IR, XRD, XPS, and EXAFS analyses clarified the interaction mechanism between Cs+ and GO/CS/Cu-PBA. Highly selective fixation of Cs+ by Cu-PBA was accompanied by the release of K+/Cu2+ and a crystalline phase transition. The adsorption of Cs+ by GO was mainly correlated with the electrostatic attraction by –COO− and C-OH groups. The confinement of Cu-PBA by GO/CS aerogel is of much potential for the practical treatment of cesium-containing radioactive wastewater.

Water-based ferrofluid with tunable stability and its significance in nuclear wastewater treatment

The treatment of nuclear wastewater is one of the most urgent and arduous tasks currently, but traditional adsorption materials are significantly limited in practice due to their high demands on auxiliary operations (e.g., shaking or centrifugation) caused by poor stability or recyclability. To tackle this challenge, a water-based ferrofluid composed of magnetic nanoparticles grown in polyethylenimine branches is reported and applied to nuclear wastewater treatment. It is demonstrated that the ferrofluid can keep stable spontaneously in a wide pH range (3–11) out of their ultra-small size, strong electropositivity as well as high charge buffering capacity to achieve shaker-free adsorption, and can be magnetically separated after the neutralization of their positive charge to achieve convenient recycle. Meanwhile, it is found that the ferrofluid shows wide pH/adsorbate applicability and strong ion selectivity in radionuclides absorption. Furthermore, it is anticipated to achieve maximum adsorption capacities for U(VI), Sr(II) and Co(II) as high as 331.5, 427.8 and 759.6 mg/g, respectively. With these characteristics, this ferrofluid outperforms other reported adsorbents. In conclusion, this work provides a practical and effective radioactive wastewater treatment strategy, and enlightens the development of materials for other applications facing the dilemma of incompatible stability and recyclability.

Efficient photoreduction strategy for uranium immobilization based on graphite carbon nitride/activated carbon nanocomposites

Uranium removal from aqueous solutions using environmentally friendly photocatalytic technology is a novel approach for resource recovery. Herein, carbon nitride/activated carbon composite materials (CN/AC) were investigated for U(VI) reduction under visible light. An exceptional boost in photocatalytic activity was observed for CN/AC composites (up to 70 times over the conventional bulk g-C3N4). The strong interactive conjugated π-bond structure between g-C3N4 and AC accelerated the migration of carriers and then prolonged the electron lifetime. CN/AC composites exhibited excellent compatibility with different water substrates and were resilience to a wide range of pH changes and abundant competitive anions/cations. Quenching experiments and electron microscopy characterization indicated that U(VI) was reduced by photogenerated electrons and deposited on the edge of CN/AC composites. The low-cost, high-performance carbon-based composite material proposed in this work is a potential candidate for the efficient treatment of radioactive wastewater.

Opportunities and challenges of high-pressure ion exchange chromatography for nuclide separation and enrichment

With the rapid development of the nuclear industry, more-stringent requirements are proposed for high-level radioactive waste liquid treatment and the enrichment of isotope products. High-pressure ion exchange chromatography has been widely accepted for the fine separation of elements and nuclides due to its advantages, such as high efficiency, environmental friendliness, ease of operation, and feasibility for large-scale industrial applications. Here, we summarized the evolution of high-pressure ion exchange chromatography and the relevant research progress in ion exchange equilibrium and related separation technology. The prospects for application of high-pressure ion exchange chromatography to rare earth elements, actinide elements and isotope separation were discussed. High-pressure ion exchange chromatography represents a promising strategy for the extraction of rare earth elements and actinide elements from high-level radioactive waste liquid, as well as being an effective method for the automated production of high purity isotope products with great environmental benefits. The separation of radionuclides from radioactive liquid are essential for not only the recovery of valuable radionuclides, but also the purification treatment of radioactive waste water. High-pressure ion exchange chromatography has been widely accepted for the fine separation of elements and nuclides due to its advantages including high efficiency, environmental friendliness, ease of operation, and feasibility for large-scale industrial applications.

Study on the treatment of radioactive wastewater by non-contact membrane distillation

Conventional contact membrane distillation technology has some problems, such as membrane fouling and wetting, resulting in short membrane life, low permeate flux, and instability, which limit its industrial application. Here, a non-contact membrane distillation method is proposed for radioactive wastewater treatment. The effects of hot-side inlet temperature, hot-side flow rate, sweeping gas temperature, and cold-side flow rate on permeate flux are examined. The purification ability of this method for strontium ion in simulated radioactive wastewater and actual radioactive wastewater from uranium-containing hydrometallurgical purification plant was investigated. Under the optimized conditions, the permeate flux of non-contact membrane distillation unit reaches 24.87 kg/(m2·h), the rejection rate of Sr2+ in simulated radioactive wastewater is more than 99.99%, and the decontamination factor can reach more than 4.5 × 106. The total α and β activity concentrations in the radioactive wastewater are 21279.7 Bq/L and 17811.9 Bq/L, respectively, while the actual α and β activity concentrations of the distillate produced by the membrane distillation device are 0.205 Bq/L and 0.877 Bq/L, respectively. Overall, the proposed method has the advantages of long membrane service life, high and stable permeate flux, which can facilitate its large-scale industrial application in volume reduction and deep purification of radioactive wastewater.

Evaluation of Utility of the Cement Solidification Process of Waste Ion Exchange Resin.

The present study aimed to evaluate the utility of the cement solidification process for stably disposing of waste ion exchange resin generated during the treatment of radioactive wastewater. The cement solidification process using the in-drum mixing system was selected to be used for the solidification process of waste ion exchange resins. The disposal safety of waste forms was evaluated according to the waste acceptance criteria (WAC) applicable to domestic waste disposal sites, and the tests were conducted for six test items provided in the WAC. A total of 15 representative samples were collected from the waste-form drums produced using the optimum operating conditions, and their structural stability for disposal considerations was evaluated. In addition, the leaching index of the samples was 11.05, 10.12, 8.39 for Co, Sr, and Cs, respectively, and it was found to exceed 6, the leaching index standard of WAC. The results confirmed that cement waste forms including waste ion exchange resins produced through this process were considered to be conforming to the requirements for disposal safety.

Selective removal of Sr(II) from saliferous radioactive wastewater by capacitive deionization

90Sr-containing radioactive wastewater during Fukushima nuclear accident (FNA) aroused extensive consideration for its disposal. Massive coexisted Na+ ions seriously inhibited Sr2+ removal, aggravating the expenditure of radioactive wastewater treatment. Herein, a chestnut shell derived porous carbon material modified with aryl diazonium salt (ADS) of sodium 4-aminoazobenzene-4′-sulfonate (SPAC) was developed as capacitive deionization electrode for selective removal of Sr2+ from saliferous radioactive wastewater. Based on ADS modification, the Sr2+ electrosorption capacity of SPAC electrode was improved to 33.11 mg g−1 with fast ion removal rate of 2.89 mg g−1 min−1, comparing with only 16.10 mg g−1 before modification. The isothermal adsorption and kinetics by SPAC electrode fitted well with Langmuir and pseudo-second-order model, achieving a maximum Sr2+ electrosorption capacity of 58.21 mg g−1, superior cycling stability, and excellent charge efficiency (77.63%). Fascinatingly, the SPAC electrode exhibited superhigh Sr2+ selectivity of 70.65 against Na+ in Na+–Sr2+ mixed solution with molar ratio of Na+:Sr2+ as 20:1. Density functional theory (DFT) simulation, combining with electrochemical and spectral analyses, revealed that the high overlap of electron cloud between Sr2+ ion and anionic sulfonic group (–SO3-) provided SPAC with remarkable selectivity of Sr2+ ion, and illustrated the ion-swapping mechanism of Sr2+ selectivity.

Temperature-responsive alkaline aqueous biphasic system for radioactive wastewater treatment

The treatment of anionic 99TcO4− in the waste tank with high alkalinity is still very challenging. In this work, a new temperature-responsive alkaline aqueous biphasic system (ABS) based on (tri-n‑butyl)-n-tetradecyl phosphonium chloride (P44414Cl) was developed to remove radioactive 99TcO4−. The phase transition mechanism was studied by cloud point titration, small-angel X-ray scattering, dynamic light scattering, and molecular dynamic simulations. As the NaOH concentration or temperature increased, the P44414+ micelle could grow and aggregate. This micelle showed a particularly high affinity toward ReO4−/99TcO4− compared to other competing anions and could directly extract more than 98.6% of 99TcO4− from simulated radioactive tank waste supernatant. Furthermore, the loaded 99TcO4− could be easily stripped by using concentrated nitric acid rather than metal salt-based reductants. This work clearly demonstrates that the alkaline ABS is a promising separation system for solving the technetium problem in the alkaline waste tank.

Rapid one-step preparation of a carboxymethyl chitosan gel with a novel crosslinker for efficient adsorption of Sr2+

A novel crosslinker, iminodiacetic acid (IA), was used to fabricate a three-dimensional carboxymethyl chitosan (CMC) hydrogel. The gel was synthesized using a simple one-step method within a short reaction time of 2 min. IA also plays the role of adsorption site provider. Fourier transform infrared spectroscopy (FT-IR) and X-Ray Diffraction (XRD) demonstrated the crosslinking reaction. The swelling ratio and the surface morphology can be modulated by changing the CMC:IA ratio, resulting from the changes on the degree of cross-linking and the number of functional groups, which in turn greatly affect the adsorption capacity for Sr2+. The maximum adsorption capacity can reach 144.73 mg/g, depending on the pH value. XPS spectra indicate that the adsorption derives from the ion exchange of Na+ to Sr2+, mainly interacting with the carboxyl radicals on CMC as well as IA. In addition, the gel shows high mechanical strength, which is helpful to the application and recycle in wastewater treatment. The facile and fast synthesis, high adsorption capacity and strong mechanical strength prove that the gel is a promising material for radioactive wastewater treatment.

Effect of Bi2WO6 nanoflowers on the U(VI) removal from water: Roles of adsorption and photoreduction

The efficient, safe, low-cost and easy to treatment of uranium(U(VI))-containing wastewater is still an imminent problem. Herein, the hierarchical hollow-spherical bismuth tungstate (Bi2WO6) was prepared by hydrothermal method, and sufficiently characterized by morphology and photoelectrochemical properties. In this research, we not only discussed the adsorption performance of U(VI), but also investigated the photocatalytic reduction performance of U(VI), so as to provide technical support for the treatment of U(VI)-containing wastewater in the future. The adsorption procedure complied with the pseudo-second-order model, implying surface complexation or chemisorption. Besides, under visible-light irradiation lasting for 600 min, the photoreduction removal rate of U(VI) was 53% (just adding 2.0 mg Bi2WO6), without adding the h+ scavenger, due to the harvest absorption of solar energy, hierarchically porous structure and synergic effect of adsorption and photocatalysis. Furthermore, the adsorption mechanism and photocatalytic reduction mechanism of Bi2WO6 for U(VI) were revealed. The metal 3O and O3H bonds in Bi2WO6 crystal were the active coordination sites for U(VI) adsorption, while •O2− and e- were the main active species for U(VI) photocatalytic reduction. Although the mechanisms of adsorption and photocatalytic reactions were different, there was a synergistic effect in the process of practical for application removing U(VI) by Bi2WO6. Consequently, the hierarchical nanosheets-assembled Bi2WO6 microspheres could be considered as a good candidate for visible-light-responsive photocatalyst in radioactive wastewater treatment.

Study on the Treatment of Radioactive Wastewater By Non-Contact Membrane Distillation

Study on the Treatment of Radioactive Wastewater By Non-Contact Membrane Distillation

Effective inspissation of uranium(VI) from radioactive wastewater using flow electrode capacitive deionization

• Flow electrode capacitive deionization was utilized for effective inspissation of U(VI) from wastewater. • Removal ratio of U(VI) maintained 99% even after 48th operation cycles. • The excellent adsorption capacity of U(VI) is credited to electrosorption and electroreduction. • The original concentration of 60 mg L −1 was effectively concentrated to 2843 mg L −1 by FCDI process. The treatment for large amounts of low concentration radioactive wastewater has always been a worldwide problem, just like the Fukushima nuclear power plant is facing the problem of insufficient storage space. In this work, we have assessed the effectiveness of flow electrode capacitive deionization (FCDI) as a recently developed electrochemical technology to concentrate the radioactive wastewater for the first time. Continuous batch experiments demonstrated that uranium (U) can accumulate into the electrolyte and on activated carbon at the same time in the flow electrode, and the removal efficiency of U remained over 99% during each cycle. Combined with XPS analysis, the migration route and valence change of U in the flow electrode were revealed, which helped to understand the high adsorption capacity of U in FCDI. Long-term batch experiments exhibited that the low concentration of feed water (60 mg L −1 U) could be concentrated by 47 times after 48th continuous cycles, achieving a final concentration of 2843 mg L −1 U in the electrolyte, and 40 mL reduced volume of uranium-containing water from 2,400 mL. Under optimized conditions, a charge efficiency of 86% and a low energy consumption of 2.03 mg J −1 were achieved in 360 mg L −1 initial concentration of UO 2 2+ . Overall, high removal rate, excellent concentration effect and low energy consumption make FCDI to be a promising way for radioactive wastewater treatment.

Experimental performance evaluation and model-based optimal design of a mechanical vapour recompression system for radioactive wastewater treatment

High-security and cost-effective disposal of radioactive wastewater plays a significant role in the wide deployment of nuclear energy. This paper presents an experimental study to investigate the feasibility of using mechanical vapour recompression systems for radioactive wastewater treatment, and a model-based design optimisation to maximise its economic benefits. A lab-scale mechanical vapour recompression system was established to experimentally assess its performance in terms of decontamination effect, energy efficiency, and exergy destruction. Based on the understanding of system performance, a numerical model for the proposed mechanical vapour recompression system was developed and validated, which was then utilised as a platform for optimal system design. A bi-objective design optimisation was formulated with the targets to minimise the payback period of the additional cost referencing to a traditional three-effect-evaporation system while maximising the system primary energy efficiency. Two intermediate variables, including the evaporation temperature and the heat transfer temperature difference, were selected as the optimisation variables. The experimental results verified the feasibility of using mechanical vapour recompression technology for radioactive wastewater treatment, demonstrating an excellent decontamination capability. It was found that an optimal evaporation temperature of 90 °C existed for maximising the decontamination factors for ions of strontium, cobalt, and cesium to 5.90 × 103, 1.45 × 104, and 1.74 × 104, respectively, while a higher system efficiency (coefficient of performance ranging from 7.33 to 8.21) has resulted when increasing the evaporation temperature (from 70 to 100 °C, correspondingly). The design optimisation resulted in an optimal Pareto front presenting the trade-off between the two optimisation objectives. By adopting the design corresponding to the optimal solutions identified, the mechanical vapour recompression system was found to feature a relative payback period of 0.69–2.32 years and a primary energy efficiency of 3.94–13.46, which outperformed a comparison case without optimisation (with that of 2.79 years and 3.03, respectively). The outcomes of study will provide guidance for the optimal application of mechanical vapour recompression evaporation system in nuclear wastewater treatment.

Synthesis of polyamide-based nanocomposites using green-synthesized chromium and copper oxides nanoparticles for the sorption of uranium from aqueous solution

Utilization of the unmodified polyamides for the adsorption of pollutants is often unsatisfactory owning to their smaller surface areas and insufficient active sites on their surfaces. The objective of this work is to modify polyamide 6 (PA6) for enhancing its adsorption capability for uranium (VI). In this study, Cr2O3@PA6 (CrO@PA6) and CuO@PA6 as modified polyamides nanocomposites were successfully synthesized and applied, for the first time, as novel nano-adsorbents to efficiently remove U(VI) from aqueous solution. The nanocomposites were synthesized by the incorporation of green-synthesized CrO and CuO nanoparticles in PA6 matrices via melt compounding technique. The synthesized materials were characterized by various techniques such as UV-Vis, TEM, SEM, EDX, DLS, zeta potential, pHPZC, FTIR, BET, XRD, and TGA analysis. Thanks to their higher surface areas and available active sites, CrO and CuO nanoparticles embedded into PA6 contribute to enhancing the adsorption capacities of CrO@PA6 and CuO@PA6 (in comparison to unmodified PA6) toward U(VI). The TGA analysis confirms the thermal stabilities of the synthesized adsorbents for U(VI) removal from contaminated water. Additionally, the results showed that the adsorption process could be well described by the pseudo-second order kinetic and Sips isotherm models. The maximum adsorption capacities for CrO@PA6 and CuO@PA6 sorbents are 61.1 mg g−1 and 53.5 mg g−1, respectively, at a solution pH of 4.5. Thermodynamic parameters indicated that the sorption process was exothermic and energetically favored. Moreover, U(VI) adsorption was also confirmed through FTIR, SEM, and EDX analysis of U(VI)-loaded adsorbents. Different mechanisms for U(VI) adsorption onto CrO@PA6 and CuO@PA6 sorbents were tentatively proposed. The recycling experiments with five adsorption-desorption cycles indicated that CrO@PA6 sorbent showed excellent reusability. A good sorption performance for U(VI) at real waste solutions is also exhibited. Based on the findings of this study, the simple synthesis process and enhanced U(VI) adsorption performance, the CrO@PA6 and CuO@PA6 nanocomposites can be applied as attractive, highly effective, reusable, and cost-effective nano-adsorbents for the efficient treatment of radioactive wastewater.

Novel donor-acceptor-acceptor ternary conjugated microporous polymers with boosting forward charge separation and suppressing backward charge recombination for photocatalytic reduction of uranium (VI)

The photoreduction of soluble U(VI) to insoluble U(IV) with conjugated microporous polymers (CMPs) is a promising channel to remove uranium from radioactive wastewater efficiently. However, the rapid backward charge recombination and unsatisfactory forward charge transfer lead to undesirable photocatalytic activity of CMPs. Herein, for the first time, a series of D-A1-A2 terpolymers is developed with statistical copolymerization through adjusting the monomer feed molar ratio (FMR) for photoreduction of uranium. Compared with D-A binary copolymer, such D−A1−A2 terpolymers can inhibit charge recombination and simultaneously facilitate charge separation due to its larger dipole moment and giant built-in electric field. Therefore, the PTrSO-2 which the FMR is 0.75: 1.0: 0.75 achieves 99.5% photocatalytic U(VI) reduction efficiency within 120 min visible-light irradiation, outshining most reported photocatalysts for such applications. This work cultivates an emerging stratagem and unconventional thinking for the development of CMPs photocatalysts used in the effective treatment of radioactive wastewater.

Non-thermal plasma irradiated polyaluminum chloride for the heterogeneous adsorption enhancement of Cs+ and Sr2+ in a binary system

The natural ecosystem will continually deteriorate for decades by the leakage of Cs and Sr isotopes. The exploration of the new materials or techniques for the efficient treatment of radioactive wastewater is critically important. In this study, a dielectric barrier discharge (DBD) configuration was constructed to operate the non-thermal plasma (NTP). The NTP was incorporated into the synthesis of polyaluminum chloride (PAC) in two different procedures to intensify the synthesis of PAC (NTP-PAC) and enhance the further removal of Cs and Sr from wastewater. The employment of NTP in two procedures both had significantly changed the physicochemical characteristics of PAC materials, which facilitated the further adsorption application of NTP-PAC on the treatment of Cs+ and Sr2+. Different molecular, morphological, and adsorption characteristics were confirmed to the NTP-PAC materials. The heterogeneous adsorption of the NTP-PAC can be appropriately fitted by both the pseudo-first-order kinetic model and the Elovich model. Both physisorption and chemisorption reaction mechanisms were ensured for the heterogeneous adsorption of the NTP-PAC material towards Cs+ and Sr2+, which guaranteed the excellent adsorption performance of NTP-PAC materials compared to PAC. The electron collisions caused by NTP with alum pulp created highly reactive growth precursors and intensified the nucleation and hydrolysis polymerization of PAC. The employment of NTP explicitly broadens the reaction pathways between PAC and cationic contaminants in the aqueous environment, which expands the application area of PAC materials in environmental sustainability.

Highly Efficient Uptake of TcO4 - by Imidazolium-Functionalized Wood Sawdust.

99Tc is a radioactive fission product, mainly in the form of TcO4–, with good solubility and mobility in the environment. The development of effective and inexpensive materials to remove TcO4– from nuclear industry wastewater or contaminated water is significant. Wood sawdust is a byproduct of the wood processing industry and is an abundant, low-cost, and sustainable material. The mesostructure of wood consists of numerous hollow cells that are joined endwise to form an interconnected channel matrix capable of rapid transfer of ions. Imidazolium-functionalized wood sawdust (IM-WS) was synthesized using natural wood sawdust by a two-step reaction. It has excellent properties of TcO4–/ReO4– adsorption including rapid adsorption dynamics (30 s to equilibrium), good adsorption stability (pH 3–9), high selectivity (adsorption of 45.4 Re % in 1000 times excess of NO3– ions, 76.6 Re % in 6000 times excess of SO42– ions, and 92.2 Tc % in a simulated mixed solution; after adsorption, the concentration of TcO4– decreased to 0.056 ppb from the initial concentration of 12.09 ppb in 1000 times excess of SO42−), and in particular low production costs. These characteristics give it great prospects for low-level radioactive wastewater treatment and environmental remediation.

Enrichment and in-situ ceramic immobilization of uranium by mesoporous ZrO2/SBA-15

To simplify the treatment of radioactive wastewater and reduce the secondary pollution, in this work, mesoporous ZrO2/SBA-15 was synthesized and employed for the first time as both the adsorbents and crystalline matrices for efficient enrichment and in-situ immobilization of U in radioactive wastewater. In general, U was efficiently enriched by using the mesoporous ZrO2/SBA-15 and then immobilized into ZrSiO4 ceramics by the followed sintering process. The U-adsorbed ZrO2/SBA-15 was changed to stable ZrSiO4–U ceramics by sintering at 1250–1450 °C for 6 h. The results also provided the evidence that both U(Ⅳ) and (Ⅵ) were incorporated into the crystal structure of ZrSiO4 by replacing Zr(Ⅳ). Furthermore, all the obtained ZrSiO4–U ceramics exhibited good aqueous durability. Given the high adsorption capacity and good aqueous durability, it is expected that the ZrO2/SBA-15 is attractive for actual applications in treatment of U containing radioactive wastewater.

Metal-free 2D/2D C3N5/GO nanosheets with customized energy-level structure for radioactive nuclear wastewater treatment

How to efficiently treat radioactive uranium-containing nuclear wastewater is one of the significant challenges to ensure the safety of nuclear technology and to avoid environmental pollution. Here we firstly prepare the metal-free 2D/2D C3N5/GO nanosheets, and customize a type-II heterojunction based on the band bending theory to achieve enhanced uranium extraction capacity via synergistic adsorption photoreduction engineering. The structure of C3N5 is explained by electron energy loss spectroscopy and synchrotron-based near-edge X-ray absorption fine structure. And C3N5 with larger π-conjugated structure expands the light response range to 747 nm, which is about 1.67 times that of C3N4. Further, we also use density functional theory to prove the existence of alternating energy levels so that photogenerated electrons could be continuously injected into the surface of GO to ensure the effective separation of electron-hole pairs and increase the material activity. The results show that the removal ratio of uranium by 2D/2D C3N5/GO heterojunction is achieved as high as 96.1% even at a low uranium concentration of 10 ppm, and reached 93.4% after exposure to gamma-ray. This work will lay a foundation for customizing the energy band structure of nonmetal-based 2D/2D nanohybrids and enriching uranium-containing wastewater through adsorption photoreduction engineering in the future.