Residual Solution Research Articles

Mechanism study and preparing (hetero)arylidene malononitriles through a greener and scalable catalytic strategy

One of the important concerns in the field of catalysis is to find a reliable route to reduce the transition energies to reach the corresponding product. The mechanism of Knoevenagel condensation of 2-chlorobenzaldehyde and malononitrile in the presence of imidazole, an organocatalyst, is investigated through control experiments. In this study, the interactions and intermediates in synthesizing 2-chlorobenzylidenemahmonitrile (CS) are studied by FTIR and NMR analyses. First, a screen activity of seven nitrogen-based organocatalysts for preparing 2-chlorobenzylidenemahmonitrile (CS) was conducted in ethanol, an eco-friendly medium. The conversion of 100 % and excellent yields were obtained in a short reaction time. The products could be crystallized directly from the reaction solution. After separating pure products, the residue solution was employed directly in the next run without any concentration, activation, purification, or separation. Then, the generality and substrate scope of the new strategy were investigated in the presence of imidazole as a selected nitrogen-based organocatalyst. In addition, the scale-up synthesis of 2-chlorobenzylidenemahmonitrile (CS) was carried out, afforded crystalline products with 95 ± 2 % yield in five consecutive runs. Energy efficiency, cost saving, greener conditions, the use of catalytic loading organocatalyst and its high recyclability, prevention of waste, and recycling extractant by a rotary evaporator for non-crystallized products, demonstrate the newly developed metal-free and halogen-free catalytic methodology as a more sustainable process for the synthesis of (hetero-)arylidene malononitriles in the laboratory and industrial scale.

The efficacy of a device-based approach to microorganism disinfection and protein removal for orthokeratology lenses in varied clinical circumstances

PurposeRigidCare is an electrolysis-based device that recently obtained approval from the US’s FDA to sterilise microorganisms and remove proteins for orthokeratology (O-K) lenses. The study was conducted to investigate the device’s performance in varied clinical circumstances. MethodsTrial lenses and private lenses were employed by O-K lens wearers from five hospitals for an evaluation of disinfection and sterilisation and an assessment of protein removal, respectively. Menicon multipurpose solution and protein remover were selected for use with the control group. Following the instructions, pre-cleaning lens samples, post-cleaning lens samples and residual solution samples of trial lenses of the experimental and control groups were collected for microorganism examinations by an experienced third-party testing organisation. The levels of protein deposition for these two approaches were rated by senior O-K experts. Categorical variables were analysed using statistical tests, such as the chi-squared test and Fisher’s exact test. ResultsThe microbial positive rate detected from the pre-cleaning and post-cleaning lens samples and the residual solution of the trial lenses for the experimental and control group was 4/76 vs 1/74 (P = 0.37), 1/76 vs 0/74 (P = 1.00) and 0/76 vs 8/74 (P = 0.006), respectively. Following protein removal, the experimental group exhibited a significantly higher overall proportion of lenses rated as ‘clean’ or with a ‘mild deposit’ (96.4 %, 79/82) compared to the control group (85.7 %, 66/77), with a significant difference (P < 0.05). ConclusionThis multi-center study demonstrated that RigidCare exhibited superior efficacy in disinfection, sterilisation and protein removal as compared to Menicon multipurpose solution and protein remover.

Study on mechanical properties and microstructure of fly-ash-based geopolymer for solidifying waste mud

The chemical solidification of construction waste mud presents a strategy for mitigating environmental concerns as well as addressing problematic geotechnical engineering properties. The present study explores the efficacy of utilizing fly ash (FA)-based geopolymer, activated by calcium carbide residue (CCR) and sodium silicate solution (NS), for waste mud solidification. An unconfined compressive strength (UCS) test was conducted to ascertain the optimal CCR/NS ratio. Supplementary tests were executed to examine factors such as water content, pH level, X-ray diffractometry (XRD), scanning electron microscopy (SEM), and natural dehydration. According to the UCS results, an optimal 28-day strength of 2.2 MPa was observed when employing a CCR/NS ratio of 6:4. A notable reduction in the water content of the mud was achieved in the short term, with the most effective results observed at a pH level of 12. Microstructural analyses indicated that calcium silicate hydrate (CSH) and aluminosilicate-Na hydrate (NASH) acted as the primary cementitious products, filling pores and creating bonds with particles to facilitate strength development. Variations in crack morphology and water content during the natural dehydration process were also analyzed for both solidified and untreated mud. The findings suggest that solidified mud holds promise for application in subgrade engineering projects, potentially diverting significant volumes of waste mud and industrial by-products such as CCR and FA away from landfills.

A novel process for the desalination of MSWI fly ash via in-situ leachate concentrate washing and residue solution electrolysis

Desalination of municipal solid waste incineration (MSWI) fly ash is necessary prior to its disposal. Water washing followed by evaporation crystallization for salt extraction is a popular desalination process for MSWI fly ash, while facing large water consumption, high evaporation energy consumption, and difficulties in crystalline NaCl selling. Leachate concentrate is another hazardous waste produced in MSWI plant which is hard to be degraded. In this work, a novel process for the desalination of MSWI fly ash via leachate concentrate washing and residue solution electrolysis was proposed. The effects of liquid-to-solid (L/S) ratio and washing step were discussed. Low-carbon electrolysis strategy for the high-salt washed leachate concentrate was explored. Results showed that leachate concentrate washing displayed the similar desalination performance to water washing and the preferred L/S ratio was 3. The dissolution of Cl in fly ash exceeded 92 % after its twice washing. The desalination capacity of leachate concentrate decreased sharply with increasing using times while its salinity increased steadily. With CO2 injection in a regulating chamber, stable electrolysis of the washed leachate concentrate was achieved. The findings are expected to provide guidance on the treatment of MSWI fly ash, leachate concentrate as well as high-salt wastewater in other fields.

Game-Theoretic Inverse Reinforcement Learning: A Differential Pontryagin's Maximum Principle Approach.

This brief proposes a game-theoretic inverse reinforcement learning (GT-IRL) framework, which aims to learn the parameters in both the dynamic system and individual cost function of multistage games from demonstrated trajectories. Different from the probabilistic approaches in computer science community and residual minimization solutions in control community, our framework addresses the problem in a deterministic setting by differentiating Pontryagin's maximum principle (PMP) equations of open-loop Nash equilibrium (OLNE), which is inspired by Jin et al. (2020). The differentiated equations for a multi-player nonzero-sum multistage game are shown to be equivalent to the PMP equations for another affine-quadratic nonzero-sum multistage game and can be solved by some explicit recursions. A similar result is established for two-player zero-sum games. Simulation examples are presented to demonstrate the effectiveness of our proposed algorithms.

The residual symmetry, Bäcklund transformations, CRE integrability and interaction solutions: (2+1)-dimensional Chaffee–Infante equation

In this paper, we consider the (2+1)-dimensional Chaffee–Infante equation, which occurs in the fields of fluid dynamics, high-energy physics, electronic science etc. We build Bäcklund transformations and residual symmetries in nonlocal structure using the Painlevé truncated expansion approach. We use a prolonged system to localize these symmetries and establish the associated one-parameter Lie transformation group. In this transformation group, we deliver new exact solution profiles via the combination of various simple (seed and tangent hyperbolic form) exact solution structures. In this manner, we acquire an infinite amount of exact solution forms methodically. Furthermore, we demonstrate that the model may be integrated in terms of consistent Riccati expansion. Using the Maple symbolic program, we derive the exact solution forms of solitary-wave and soliton-cnoidal interaction. Through 3D and 2D illustrations, we observe the dynamic analysis of the acquired solution forms.

Enhancing Palladium Recovery Rates in Industrial Residual Solutions through Electrodialysis.

Palladium is a vital commodity in the industry. To guarantee a stable supply in the future, it is imperative to adopt more effective recycling practices. In this proof-of-concept study, we explore the potential of electrodialysis to enhance the palladium concentration in a residual solution of palladium recycling, thus promoting higher recovery rates. Experiments were conducted using an industrial hydrochloric acid solution containing around 1000 mg/L of palladium, with a pH below 1. Two sets of membranes, Selemion AMVN/CMVN and Fujifilm Type 12 AEM/CEM, were tested at two current levels. The Fujifilm membranes, which are designed for low permeability of water, show promising results, recovering around 40% of palladium within a two-hour timeframe. The Selemion membranes were inefficient due to excessive water transport. All membranes accumulated palladium in their structures. Anion-exchange membranes showed higher palladium accumulation at lower currents, while cation-exchange membranes exhibited increased palladium accumulation at higher currents. Owing to the low concentration of palladium and the presence of abundant competing ions, the current efficiency remained below 2%. Our findings indicate a strong potential for augmenting the palladium stage in industrial draw solutions through electrodialysis, emphasizing the importance of membrane properties and process parameters to ensure a viable process. Beyond the prominent criteria of high permselectivity and low resistance, minimizing the permeability of water within IEMs remains a key challenge to mitigating the efficiency loss associated with uncontrolled mixing of the electrolyte solution.

Separation and recovery of zinc from blast furnace dust via coordination leaching of Cl− and hydrolysis of NH4+

Blast furnace dust (BFD) is a by-product of iron-making process, a typical hazardous waste containing abundant recyclable components. In this study, a NH4Cl cooperative coordination leaching method was proposed for the selective separation and recovery of zinc from BFD. The thermodynamic analysis results revealed that ZnO and ZnSO4 from BFD can be converted to zinc-chlorine coordination compounds (ZnCli2−i, i = 1,2,3,4) in the cooperative actions of NH4+ and Cl− ions. The experimental results showed that the leaching efficiency of zinc reached 85.64% while iron and carbon was enriched from 46.76% to 57.96% under the optimal experimental conditions. The leaching residue with a total content 2.53% of Zn, Cl, K and Na can be returned to sintering for the recovery of iron and carbon. Moreover, the XRD, SEM-EDS and chemical phase analysis results of BFD and residue demonstrated that a small amount ZnO, ZnS and ZnFe2O4 were not leached and remained in the leaching residue. Additionally, a novel method of low-temperature crystallization was adopted to recover zinc from filtrate. The crystallization efficiency of zinc reached 80.96% and the obtained crystal was confirmed to be special Zn(NH3)2Cl2. Thus, this work not only achieved the separation and recovery of zinc from BFD, but also solved the disposal problem of leaching residue and crystallization solution, providing a guidance for the resource utilization of hazardous BFD.

Improving the cementation effect of copper on gold in thiosulfate solution by pre-regulating the existing form of Cu2+

The effective recovery of Au(S2O3)23− from leachates using thiosulfate gold extraction techniques remains challenging. Metal cementation can be efficiently used to recover Au(S2O3)23−, but is easily affected by the oxidant (Cu(II)) in solution, leading to problems such as high consumption of the reduced metals and copper–gold co-precipitation. Copper powder cementation can prevent the co-precipitation of copper in solution to improve the grade of the gold product and also supplement the oxidant in the solution, thereby enhancing the cyclic leaching of gold into the solution, which can reduce production costs. In this study, copper powder was used to recover gold ions and the results showed that the gold cementation rate was negatively correlated with the Cu(NH3)42+ concentration. In order to weaken the negative influence of Cu(NH3)42+, this study proposes the application of a reduction voltage to convert Cu(NH3)42+ in solution to Cu(S2O3)35− before adding copper powder. After applying a reduction voltage of 0.14 V to a solution of 5 mmol/L CuSO4, 0.5 mol/L NH3, 0.1 mol/L Na2S2O3, and 10 mg/L Au(S2O3)23− for 20 min, the concentration of Cu(NH3)42+ in the solution changed from 5 mmol/L to 0.88 mmol/L. Under these conditions, gold ions were recovered, and the consumption of copper powder was reduced by 60%. Scanning electron microscopy and X-ray photoelectron spectroscopy characterization showed that under a applied reduction potential, the gold content on the surface of the copper powder was higher, and the Cu(II) content in the surface copper species was lower than that achieved in the direct cementation of copper powder. After cementation was completed, stirring the residual solution for 20 min restored the concentration of Cu(NH3)42+ to 4.963 mmol/L. At this point, the leaching rate of gold ore into the solution reached 89% of the first leaching, which maximized the circulation of the solution.

A dataset of gas reservoir microscopic images in Xujiahe Formation in northeast Sichuan Basin

The gas reservoir in Xujiahe Formation in northeast Sichuan Basin holds promising potential for exploration and development. In this paper, we collected and sorted the microscopic image data of the clastic reservoir of Xujiahe Formation gas reservoir in the study area, so as to further study the petrological characteristics, diagenesis, reservoir space and physical properties of the region. The reservoir rocks are mainly lithic sandstone, lithic arkose sandstone and quartz sandstone. There are intergranular solution pores, residual intergranular solution pores, intragranular solution pores, clay mineral intergranular (solution) pores and various microfractures in the reservoir space. According to the observation of the cast thin section, the pores are relatively undeveloped, while some thin sections (micro-cracks) are relatively developed. Based on thin section identification and observation, the sandstone reservoirs of Xujiahe Formation in the study area have undergone processes such as compaction, cementation, dissolution and tectonic fracture. This dataset can provide a direct source for the comparative analysis and reference of sandstone image data. Moreover, it can serve as a benchmark for the intelligent identification of lithology.

Recyclable cellulose nanofibrils composite film derived from bamboo fiber tableware waste

The world faces a serious environmental pollution from petrochemical plastic. Sustainable green cellulose films can be employed as an alternative to plastic films, thus providing a solution to the pollution caused by the latter. In this study, cellulose nanofibrils (CNF) with low food content were extracted from food solutions of discarded bamboo fiber tableware using micro-nano bubble technology. The CNF were then stabilized in oil-water emulsions to form a biobased CNF-food solution composite film using the solvent casting method. The composite film treated with micro-nano bubbles called post-cleaning bamboo fiber tableware(PS-BFT) exhibited a significantly better mechanical strength, transparency, and thermal performance than those of stained bamboo fiber tableware(S-BFT), and even better transparency and thermal performance than those of clean bamboo fiber tableware(C-BFT). Furthermore, microscopic observations revealed that the films with a high food content exhibited a clear multilayer structure, while those with a lower food content presented only a few agglomerations of food solution-fiber. This confirms the cleaning effect of micro-nano bubbles on the residual food solution in discarded tableware and demonstrates their potential in the high-value utilization of secondary fibers.

Integrating anaerobic acidification with two-stage forward osmosis concentration for simultaneously recovering organic matter, nitrogen and phosphorus from municipal wastewater

In order to meet the demand of municipal wastewater for low-carbon treatment and resource recovery, a novel process of anaerobic acidification membrane bioreactor (AAMBR) assisted with a two-stage forward osmosis (FO) (FO-AAMBR-FO) was developed for simultaneously recovering organic matter and nutrients from municipal wastewater. The results indicated that the first FO process concentrated the municipal wastewater to one tenth of the initial volume. The corresponding chemical oxygen demand (COD), ammonia nitrogen (NH4+-N) and total phosphorus (TP) concentration reached up to 2800, 200 and 33 mg/L, respectively. Subsequently, the AAMBR was operated at pH value of 10 for treating the concentration of municipal wastewater, in which the organic matter was successfully converted to acetic acid and propionic acid with a total volatile fatty acids (VFAs) concentration of 1787 mg COD/L and a VFAs production efficiency of 62.36 % during 47 days of stable operation. After that, the NH4+-N and TP concentration in the effluent of the AAMBR were further concentrated to 175 and 36.7 mg/L, respectively, by the second FO process. The struvite was successfully recovered with NH4+-N and TP recovery rate of 94.53 % and 98.59 %, respectively. Correspondingly, the VFAs, NH4+-N and TP concentrations in the residual solution were 2905 mg COD/L, 11.8 and 7.92 mg/L, respectively, which could be used as the raw material for the synthesis of polyhydroxyalkanoate (PHA). Results reported here demonstrated that the FO-AAMBR-FO is a promising wastewater treatment technology for simultaneous recovery of organic matter (in form of VFAs) and nutrients (in form of struvite).

Effect of structure and phase composition on the physical and mechanical properties of hot extruded titanium alloy Ti–3Al–2.5V tubes

This study investigates the impact the hot extrusion process variables on the physical and mechanical properties of Ti–3Al–V alloy The research examines four tube segments extracted from various hot-extruded tubes of Ti–3Al–2.5V alloy, with an outer diameter (OD) of 90 mm and a wall thickness of 20 mm. The manufacturing process involves expanding sleeves with a horizontal hydraulic press to achieve an OD of 195 mm, followed by heating to 850–865 °C prior to extrusion. The tube segments are labeled as 1, 2, 3, and 4, corresponding to their order of production. Our findings demonstrate that an increase in the number of extrusions in the α + β area from tube 1 to tube 4 leads to a reduction in the primary α-phase volume fraction and an increase in the β-transformed structure volume fraction. These changes are attributed to the higher final extrusion temperature resulting from more intense deformation heating during hot tooling (die and mandrel) processes. Additionally, elevating the final extrusion temperature from tube 1 to tube 4 leads to a notable decrease in the residual β-solid solution volume fraction and a reduction in the “sharpness” of the α-phase tangent-oriented texture. The alterations in the structural and phase state of the alloy from tube 1 to tube 4 are found to influence the contact modulus of elasticity and microhardness. These identified relationships can be utilized to optimize the process variables for the extrusion of multiple Ti–3Al–2.5V alloy tubes.

Carbon dioxide capture with aqueous calcium carbide residual solution for calcium carbonate synthesis and its use as an epoxy resin filler

Calcium carbide residue (CCR) is a waste obtained from the production of acetylene gas by the hydration reaction of calcium carbide. This residue is generated in large quantities annually and requires appropriate disposal. The main composition of the residue is calcium hydroxide (Ca(OH)2). Ca(OH)2 can react with CO2 gas and form CaCO3 particles. This process is well known but not very attractive since Ca(OH)2 is obtained from limestone using an energy-intensive thermal conversion process. This paper examined the synthesis of CaCO3 from CCR solutions by capturing CO2 with the aid of triethanolamine (TEA) solutions at doses of 0, 5, 10 and 20% w/w. The precipitated CaCO3 was characterized, and the application of CaCO3 as a filler in epoxy resin was tested. The results showed that the precipitated CaCO3 was mainly calcite, with a 76.6% yield. Cubic calcite was primarily obtained in TEA solutions, whereas small and agglomerated spherical vaterite and cubic calcite particles were formed in non-TEA solutions. The CaCO3-filled epoxy composites showed higher compressive strength than the neat resin. However, the transparency of specimen plates was reduced. These results can serve as guidelines for the application of CCR slurry filtrate obtained from the sedimentation ponds of acetylene plants and help to reduce the amount of wastewater that needs to be treated. CO2 gas from industrial flue gas combined with TEA solution could be applied to precipitate CaCO3 for carbon-neutral manufacturing.

Residual symmetry, CRE integrability and interaction solutions of two higher-dimensional shallow water wave equations

Two (3+1)-dimensional shallow water wave equations are studied by using residual symmetry and the consistent Riccati expansion (CRE) method. Through localization of residual symmetries, symmetry reduction solutions of the two equations are obtained. The CRE method is applied to the two equations to obtain new Bäcklund transformations from which a type of interesting interaction solution between solitons and periodic waves is generated.

Heap leaching of ion adsorption rare earth ores and REEs recovery from leachate with lixiviant regeneration

In this work, semi-industrial scale heap leaching of 200 t ion adsorption rare earth ores (IRE-ore) and rare earth elements (REEs) recovery from lixivium was first conducted. Biosynthetic citrate/(Na)3Cit, a typical microbial metabolite, was chosen as the lixiviant to conduct heap leaching. Subsequently, an organic precipitation method was proposed, which used oxalic acid to effectively recover REEs and reduce the production cost by lixiviant regeneration. The results showed that the heap leaching efficiency of REEs reached 98 % with a lixiviant concentration of 50 mmol/L and a solid-liquid ratio of 1:2. The lixiviant can be regenerated during the precipitation process, with REE yields and impurity aluminum yields of 94.5 % and 7.4 %, respectively. The residual solution can then be cyclically used as a new lixiviant after simple adjustment. High-quality rare earth concentrates with a rare earth oxide (REO) content of 96 % can be finally obtained after roasting. This work provides an eco-friendly alternative for IRE-ore extraction to solve the environmental issues caused by traditional technology. The results proved feasibility and provided a foundation for in situ (bio)leaching processes in further industrial tests and production.

Solute drag-controlled grain growth in magnesium investigated by quasi in-situ orientation mapping and level-set simulations

Critical properties of metallic materials, such as the yield stress, corrosion resistance and ductility depend on the microstructure and its grain size and size distribution. Solute atoms that favorably segregate to grain boundaries produce a pinning atmosphere that exerts a drag pressure on the boundary motion, which strongly affects the grain growth behavior during annealing. In the current work, the characteristics of grain growth in an annealed Mg-1 wt.%Mn-1 wt.%Nd magnesium alloy were investigated by advanced experimental and modeling techniques. Systematic quasi in-situ orientation mappings with a scanning electron microscope were performed to track the evolution of local and global microstructural characteristics as a function of annealing time. Solute segregation at targeted grain boundaries was measured using three-dimensional atom probe tomography. Level-set computer simulations were carried with different setups of driving forces to explore their contribution to the microstructure development with and without solute drag. The results showed that the favorable growth advantage for some grains leading to a transient stage of abnormal grain growth is controlled by several drivers with varying importance at different stages of annealing. For longer annealing times, residual dislocation density gradients between large and smaller grains are no longer important, which leads to microstructure stability due to predominant solute drag. Local fluctuations in residual dislocation energy and solute concentration near grain boundaries cause different boundary segments to migrate at different rates, which affects the average growth rate of large grains and their evolved shape.

A hydrate-based zero liquid discharge method for high-concentration organic wastewater: resource recovery and water reclamation

High-concentration organic wastewater has become a great challenge for wastewater treatment due to its toxicity and non-biodegradability. Traditional water treatment methods focus on removing or destroying organic pollutants rather than considering the high-concentration organic wastewater as a resource. As an ambitious sustainability goal, resource recovery from wastewater to achieve zero liquid discharge (ZLD) has attracted widespread attention. Here, a hydrate-based method is proposed to treat textile wastewater to facilitate the reuse of dyes and enhance water reclamation. The mechanism of interaction between hydrate and organic pollutants was invested. The results show that organic pollutants are rejected from the growing hydrate lattice and concentrated in the residual solution. This method can achieve a max removal efficiency of 93.6% and a water production rate of 80%. In the range of 0–2000 mg/L, the concentration of organic pollutants does not affect the removal effect and water production rate. The concentrated dye can be reused again. The proposed method exhibits potential for recovering resource and clean water from wastewater while achieving ZLD.

Recycling industrial alkaline solutions for soil stabilization by low-concentrated fly ash-based alkali cements

This study aims to evaluate the usability of a recycled alkaline solution, a residue from cleaning iron plates in the car manufacturing industry, to enhance the strength and stiffness of clayey soil by carrying out unconfined compressive strength (UCS), indirect tensile strength (ITS), ultrasonic pulse velocity (UPV) and microstructural (SEM, XRD) tests. High- and low- calcium fly ashes with percentages of 10% to 40% and 10% to 30%, respectively, were independently introduced into the alkaline activation process to determine the proper type and content of precursors at room temperature. Two mixtures of the residual cleaning solution blended with 2 M and 4 M NaOH solutions at a weight ratio of one were also utilized to determine how efficiently binary solutions could improve the performance of the parent clay soil. These experiments revealed that all mixtures of the residual alkaline solution work better to activate high-calcium fly ash as compared to the low-calcium fly ash in terms of both mechanical strength and stiffness. The sample of high-calcium fly ash with fly ash/solid and Na/ash ratios equal to 30% and 0.037, respectively, experienced the highest improvement. A microstructural analysis showed the formation of C-(A)-S-H and N–(C)–A–S–H gels in the corresponding sample, thus providing a considerably dense structure, which in turn significantly contributed to the enhancement of the maximum strength and stiffness of the treated soil. In fact, the high-calcium precursor proved to be the best candidate for a low-range alkaline activator because it contributes more calcium to a low-alkaline environment. An environmental impact assessment was also carried out to compare the CO2 emissions of clays treated with the 4 M NaOH binary solutions tested in this study with those conventionally stabilized by cement and lime and also those treated traditionally with commercial 2, 4, and 8 M NaOH. The samples in this study treated with environmentally friendly binary solutions (residual cleaning solution blended with 2 M and 4 M NaOH solutions at a weight ratio of one) performed better in terms of both CO2 emissions and strength gain compared to the samples stabilized with conventional materials.

The Development and Deployment of Degradable Temporary Plugging Material for Ultra-Deepwater Wells

The fractured granite reservoir is well developed in Yongle block, which leads to severe drilling fluid loss-circulation. To solve the technical problem of both plugging and reservoir protection, on the basis of comprehensive literature research and laboratory tests at home and abroad, a polymer with an appropriate molecular weight, an organic crosslinking agent and other auxiliary materials were screened. In addition, a kind of high-temperature resistant loss-circulation plugging gel, which could be formed by timing and self-degradation, was developed. The high-strength gel loss-circulation system can be established by the development of a dynamic covalent borate ester bond crosslinking agent, which can crosslink with polyvinyl alcohol and xanthan gum. This system is of formidable strength and can be used for loss-circulation control in a fractured formation. The dynamic covalent borate ester bond tends to break due to the peroxide glue breaker under low pH levels, which can accelerate the degradation of the plugging gel into small molecules. The degradable temporary plugging material can ensure high-performance sealing and self-degradation capabilities of the fractured granite reservoir. The laboratory results showed that the high-performance degradable gel system was of adjustable gelling time, high gelling strength and high sealing capability. Its pressure-bearing could reach 5.8 MPa under 110 °C with 3.5 mm width of fractured granite core. Before crosslinking, the system also boasted promising thixotropy and rheology. The gel breaking time of the system was short, which could be completely broken with 6.1 h in 6% peroxide solution with pH of 4. The gelation time was related to the type of crosslinking agent, the amount of crosslinking agent and temperature. With the increase of temperature, the gelation time of gel system decreased. With the increase of the amount of the agent, the gelation time of gel system decreased. The gelation time was 105 min when using a 1% dynamic covalent borate ester bond crosslinking agent at 80 °C; the gelation time was 72 min when using a 1% dynamic covalent borate ester bond crosslinking agent at 110 °C; the gelation time was 71 min when using a 2% dynamic covalent borate ester bond crosslinking agent at 80 °C; the gelation time was 65 min when using a 2% dynamic covalent borate ester bond crosslinking agent at 110 °C; the gelation time was 72 min when using a 1% chromium crosslinking agent at 80 °C; the gelation time was 63 min when using a 2% chromium crosslinking agent at 80 °C; and the gel system had good reservoir protection performance. The permeability recovery rate was introduced to evaluate reservoir protection performance. The permeability recovery rate of using the dynamic covalent borate ester bond crosslinking agent was superior to that of using the chromium crosslinking agent. Using the dynamic covalent borate ester bond crosslinking agent, when the fracture width was 1.6 mm, the temperature was 80 °C and the soaking time was 8 h, the permeability recovery rate was 90.32%; when the fracture width was 0.75 mm, the temperature was 80 °C and the soaking time was 8 h, the permeability recovery rate was 84.53%. Using the chromium crosslinking agent, when the fracture width was 1.6 mm, the temperature was 80 °C and the soaking time was 12 h, the permeability recovery rate was 59.58%; when the fracture width was 0.75 mm, the temperature was 80 °C and the soaking time was 12 h, the permeability recovery rate was 45.65%. The viscosity of the residual solution was low and was helpful for reservoir protection during loss-circulation control under the fractured granite reservoir condition. The novel degradable temporary plugging material can solve the loss-circulation problem of the ultra-deepwater fractured granite reservoir. In addition, the material can pave the way for the exploration and development of a vast amount of hydrocarbon resources in the South China Sea.