Value-added Materials Research Articles

Hydrodeoxygenation of vanillin to 2-methoxy-4-methylphenol over carbon dots supported Pd catalyst

Vanillin hydrodeoxygenation (HDO) was studied in water and methanol using palladium-decorated carbon dots (Pd/CDs). The catalyst was synthesized from photo-reduction of palladium acetate using CDs as the reducing and dispersion agent, while CDs were produced via microwave treatment of glucose and urea. Pd/CDs were characterized with XRD, TEM, FT-IR, XPS, BET and ICP-OES. The selectivity to 2‑methoxy-4-methylphenol (MMP), at vanillin conversion of 100 % after 4.0 h was 98.8 % at 140 °C under 4.0 MPa of H2 in water with 4.58 wt.% of Pd/CDs. The stability of Pd/CDs was also investigated after four times recycle under the optimal reaction conditions. CDs supported Pd reduced with NaBH4 and hydrazine hydrate (Pd/CDs-S and Pd/CDs-H) and other carbonaceous materials (active carbon and OH functionalized multi-walled carbon nanotube) supported Pd (Pd/AC and Pd/CNTs) were also investigated for comparison. The highest selectivity to MMP achieved by Pd/CDs produced via photoreduction brings a novel use of this type of catalyst in the conversion of biomass into value-added chemicals and materials.

Unlocking the potential of phosphogypsum waste: Unified synthesis of functional metal-organic frameworks and zeolite via a sustainable valorization route

Phosphogypsum (PG) is one of the hazardous wastes generated during phosphate fertilizers production. Valorizing PG into value-added materials is needed to overcome the environmental threat of accumulating PG stockpiles. The primary chemical constituents of PG are CaSO4·2H2O, SiO2, Al2O3, P2O5, and trace metals. Herein, we employed unified strategic synthesis method to transform the main components of PG into two classes of functional porous materials in subsequent steps. The alumina and silica components were isolated to fabricate cancrinite zeolite (CAN) while the residual calcium was directed to grow Ca-based metal–organic frameworks (Ca-MOFs) in the subsequent step. The resulting zeolite with a Si/Al ratio of ∼2.2 showed enhanced CO2 capture property, which, in many respects, is better than those achieved by similar frameworks from other precursors. The unveiled MOF synthesis approach was proven to be adaptable, allowing the preparation of different Ca-MOFs from organic linkers of diverse connectivity, namely Ca-BDC, Ca-BTC, and Ca-TCPB (SBMOF-2), using the linear ditopic benzene dicarboxylate, the tritopic benzene tricarboxylate, and tetracarboxylate-based linkers, respectively. The successful assembly of the porous materials was confirmed using various characterization techniques, including XRD, SEM-EDX, FTIR, and TGA-MS. The porosity of the materials was also probed using N2 at 77 K, CO2 at different temperatures, and H2O at 298 K sorption analyses. The Ca-BTC MOF with the optimal pore aperture size (∼3.4 Å) shows a potential for water/alcohol separation with a steep and fast moisture adsorption profile and negligible alcohol uptake. The synthetic transformation approach presented in this work represents the first example of a valorization route to form extended porous structures from PG waste.

Investigation of Preparation of Slag Wool from Melting-Separated Red Mud

The preparation of high-quality inorganic fibers by centrifugation from modified melting-separated red mud, which is the product of the efficient recovery of pig iron from red mud, is a new approach to achieve large-scale production of high value-added materials from red mud. This method has a wide range of application prospects and could contribute substantially to the comprehensive utilization of bulk industrial solid waste and the development of a circular economy. In this study, melting-separated red mud was modified with water-quenched blast furnace slag, quartz sand, and quicklime. The effect of the CaO/Na2O mass ratio on the viscosity, fluidity, and crystallization performance of the melting-separated red mud was investigated; slag wool was prepared by centrifugation under laboratory conditions; and the effect of the CaO/Na2O mass ratio on the morphology and properties of the slag wool was investigated. The viscosity of modified melting-separated red mud with different CaO/Na2O mass ratios shows a decreasing trend with increasing temperature, and the fluidity increases with increasing temperature, indicating that the melt fluidity is improved. The suitable fiber-forming temperature of the melting-separated red mud shows a trend of increasing–decreasing–increasing with an increasing CaO/Na2O mass ratio, and at a CaO/Na2O ratio of 3.0, the maximum suitable fiber-forming temperature is 81 °C. Considering the feasibility of slag wool preparation from modified melting-separated red mud, the CaO/Na2O of the modified raw material system should not be higher than 3.0. The crystallization temperature of modified melting-separated red mud with different CaO/Na2O mass ratios first increases and then decreases, with a peak of 1450 °C at a CaO/Na2O ratio of 4.0. Slag wool prepared from modified melting-separated red mud with different CaO/Na2O mass ratios exhibits good properties, with a diameter of 5.47–6.67 µm and a slag ball content of 2.7–8.4%.

Co-utilization of electric arc furnace dust and copper slag for preparing zinc ferrite based on microwave roasting

The feasibility of preparing zinc ferrite from high-zinc electric arc furnace (EAF) dust and high-iron copper slag (CS) based on direct microwave roasting of the wastes together was assessed in this study, with a focus on the effect of microwave roasting temperature. According to the permittivity and permeability measurements of the raw materials, in conjunction with thermodynamic and experimental analyses, it was found that increasing temperature facilitated the formation of zinc ferrite. By fixing the Fe/Zn molar ratio of 2.0 and roasting time of 30 min, elevating the temperature from 500 ºC to 700 ºC led to a significant increase of the percentage of acid-insoluble zinc in the form of zinc ferrite from 81.48% to 94.93%. Further increase of the temperature to 900 °C could not evidently promote the formation of zinc ferrite. After removing impurities by dilute HCl solution and nano milling, the zinc ferrite product had a single phase with the purity of 99.9 wt%. It can act as a great adsorbent of heavy metal ions due to its superior adsorption capacities of 87.99 mg/g, 86.51 mg/g, 86.22 mg/g, and 90.32 mg/g for Pb(II), Cr(VI), Cd(II), and Hg(II), respectively, and as a catalyst for removing tetracycline (TC) using peroxymonosulfate (PMS) with the removal efficiency of 78.54% after 40 min under visible light irradiation. This study offers a facile method for co-utilization of EAF dust and CS to produce value-added functional materials.

Upcycling electrode materials from spent single-use zinc‑carbon/alkaline batteries into rechargeable lithium-ion battery application

Battery recycling/upcycling is a key component of modern e-waste reduction by transforming discarded electrode powder to value-added materials and chemical feedstocks for the proposed applications. In this study, electrode powder from spent zinc‑carbon/alkaline batteries was upcycled into LiMn2O4 cathode and carbon anode for rechargeable lithium-ion battery. The main metallic contents (zinc and manganese) in electrode powder were quantitatively leached using diluted H2SO4 with the presence of H2O2 as a reducing agent. By applying sequential precipitation, ZnS nanospheres and MnCO3 nanocubes were obtained as determined by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The recovered MnCO3 was heated with a stoichiometric amount of Li2CO3 to produce high crystalline and pure LiMn2O4. For the electrochemical performance, the results show that upcycled LiMn2O4 exhibits initial discharge capacity of 99.0 mAh g−1 for zc-LiMn2O4 and 111.0 mAh g−1 for al-LiMn2O4, compared to 90.4 mAh g−1 for pristine LiMn2O4. Moreover, recovered carbon materials obtained as an insoluble powder after acid leaching possess unique morphology and crystallinity. The zc‑carbon shows superior cycling performance with reversible charge capacity of 552 mAh g−1 at 1C rate after 100 cycles. This study provides the great potential for upcycling waste battery electrodes to high-value LiMn2O4 cathode and carbon anode for lithium-ion battery application.

Physical Chemistry Supports Circular Economy: Toward a Viable Use of Products from the Pyrolysis of a Refuse-Derived Fuel and Granulated Scrap Tire Rubber as Bitumen Additives

The production and maintenance of road pavements consume resources and produce wastes that are disposed of in landfills. To make more sustainable this activity, we have envisioned a method based on a circular use of residues (oil and char) from municipal solid waste pyrolysis as useful additives for producing improved asphalts and for recycling old asphalts to generate new ones, reducing at the same time the consumption of resources for the production of new road pavements and the disposal of wastes to landfills. This work aims to show the feasibility of the integration of two processes (thermal treatment of municipal solid waste on one side, and that of road pavement production on the other side) where the products deriving from waste pyrolysis become added-value materials to improve the quality of road pavements. In this contribution, we presented the effect of pyrolysis product addition on asphalt binder (bitumen) preparation and aging. Solid and liquid products, deriving from the pyrolysis of two kinds of wastes (refused derived fuel (RDF) and granulated rubber tyre waste), have been used for the preparation of asphalt binder samples. Rheological tests have been performed to determine the mechanical properties of neat asphalt binder (bitumen) and those enriched with pyrolysis derived products. Measurements to evaluate possible anti-aging effects have been also performed. The collected results indicate that char addition strengthens the overall bitumen intermolecular structure while bio-oil addition exerts a rejuvenating activity.

Sintering of silicomanganese slag-reinforced porous SiC ceramic membrane supports with high alkali corrosion resistance

Herein, we report the production of silicomanganese slag-reinforced porous SiC ceramic membrane supports with high alkali corrosion resistance through low-temperature sintering. The effects of the sintering temperature and particle size of the silicomanganese slag (SiMn-slag) on the properties of the membrane supports were studied. The optimal membrane support was obtained at 1150 °C with 20 μm SiMn-slag, which exhibited an open porosity of 41.03%, pore size of 3.15 μm, ultra-high pure water permeability of 120074.60 L·m−2·h−1·bar−1 and high bending strength of 43.18 ± 0.70 MPa. In addition to the excellent acid corrosion resistance, the prepared membrane support displayed high alkali corrosion resistance due to the neck connections that formed, comprising alkali resistant mullite, anorthite, and bustamite. This work is of great significance in guiding the production of high-performance SiC membranes at a low cost and offers a possible route for utilising solid waste as a value-added separation material.

Industrial Waste-Derived Carbon Materials as Advanced Electrodes for Supercapacitors.

Strategically upcycling industrial wastes such as petroleum coke and dye wastewater into value-added materials through scalable and economic processes is an effective way to simultaneously tackle energy and environmental issues. Doping carbon electrodes with heteroatoms proves effective in significantly enhancing electrochemical performance through alterations in electrode wettability and electrical conductivity. This work reports the use of dye wastewater as the sole dopant source to synthesize N and S co-doped petroleum coke-based activated carbon (NS-AC) by the one-step pyrolysis method. More importantly, our wastewater and petroleum coke-derived activated carbon produced on a large scale (20 kg/batch) shows a specific surface area of 2582 m2 g-1 and an energy density of about 95 Wh kg-1 in a soft-packaged full cell with 1 M TEATFB/PC as the electrolyte. The scalable production method, together with the green and sustainable process, can be easily adopted and scaled by industry without the need for complex processes and/or units, which offers a convenient and green route to produce functionalized carbons from wastes at a low cost.

Mesoporous graphitic carbon electrodes derived from boat-fruited shells of Sterculia Foetida for symmetric supercapacitors for energy storage applications

In recent years, intensive research efforts have focused on translating biomass waste into value-added carbon materials broadcasted for their significant role in energy and environmental applications. For the first time, high-performance carbonaceous materials for energy storage applications were developed from the multi-void structure of the boat-fruited shells of Sterculia Foetida (SF). In that view, synthesized mesoporous graphitic activated carbon (g-AC) via the combination of carbonization at various elevating temperatures of 700, 800, and 900 °C, respectively, and alkali activation by KOH, with a high specific surface area of 1040.5 m2 g−1 and a mesopore volume of 0.295 cm3 g−1. In a three-electrode configuration, the improved electrode (SF–K900) exhibited excellent electrochemical behavior, which was observed in an aqueous electrolyte (1 M H2SO4) with a high specific capacitance of 308.6 F/g at a current density of 1 A/g, owing to the interconnected mesopore structures and high surface area of SF-K900. The symmetric supercapacitor (SSC) delivered the specific capacitance of 138 F/g at 1 A/g with a high energy density (ED) of 13.4 Wh/kg at the power density (PD) of 24.12 kW/kg with remarkable cycle stability and supercapacitive retention of 93% over 5000 cycles. Based on the findings, it is possible to develop low-cost active electrode materials for high-rate performance SSC using mesoporous g-AC derived from SF boat-fruited shells.

Effects of facile chemical pretreatments on physical-chemical properties of large clustered and small monopodial bamboo microfibers isolated by steam explosion

To explore the facile and high-efficient combining isolation method of bamboos and develop their high value-added fiber functional materials, this study aims at investigating the effects of four chemical soaking-pretreatments on physical-chemical properties of bamboo microfibers that were isolated using eco-friendly steam explosion (SE) from four local bamboo species (Chimonobambusa quadrangularis (CQ), Qiongzhuea tumidinoda (QT), Dendrocalamus giganteus (DG), and Dendrocalamus sinicus (DS)). The variations in the micro-morphology, width distribution and major chemical composition of bamboo microfibers as well as their thermal stability, crystallinity, surface hydrophilicity, and macro- and nano- mechanical properties were comprehensively characterized. The CQ, QT, DG, and DS bamboo microfibers obtained by the combination of mild alkali pretreatment and steam explosion displayed the smallest width sizes (149.57, 150.76, 177.33, and 172.67 µm), the highest cellulose contents (68.14 %, 67.62 %, 67.92 %, and 62.36 %), and the lowest hemicellulose contents (12.64 %, 17.24 %, 15.94 %, and 16.42 %) compared to their controls. Four chemical soaking pretreatments improved the thermal stability of bamboo microfibers but generally reduced their macro- and nano-mechanical properties. The elongation at break of bamboo microfibers pretreated by mild alkaline were effectively elevated. Acid-pretreated bamboo microfibers effectively increased the hydrophobicity of cellulose microfibrils with the highest water contact angle (WCA) value (56.8°). IL-pretreated bamboo microfibers improved the surface roughness and hydrophilicity (WCA=44.3°).

Harvesting marine plastic pollutants-derived renewable energy: A comprehensive review on applied energy and sustainable approach

The inevitable use of plastics in the existing standard of life makes its way to ecosystems, predominantly into the marine ecosystem. Recent research on energy recycling from marine discarded plastics through biological, chemical, and thermal processes is summarized, which degrade plastic debris and transform it into energy-efficient products. In a system-oriented approach, different boundaries like carbon efficiency, global warming potential, cumulative energy demand, and cost of the product have been evaluated. Even these technologies may successfully reduce the yearly volume of marine plastics by up to 89% while reducing greenhouse gas emissions by 30%. Conversely, recycling a ton of marine discarded plastics may save 915 cubic feet of landfill space, 6500 kWh of energy, and barrels of oil. Energy may be recovered up to 79% from waste plastics using various techniques. Up to 84% liquid fuel had been generated, with a maximum calorific power of 45 MJ/kg. It has been shown that in Asian countries, the power generation capacity of throw-away facemask wastes regularly varies from 2256 kWh/day to 18.52 million kWh/day. Hence, the conversion of marine plastics into biofuel, syngas, biochar, hydrocarbons, electricity, and value-added functional materials by various biotechnological and chemical processes like biodegradation, pyrolysis, gasification, methanolysis, and hydrolysis should be improvised as a source of alternative energy in the immediate future. Our review signifies the potential benefits of energy harvesting technologies from marine plastics pollutants to overcome the growing challenge of energy demands and provide a long-term solution to underdeveloped and developing countries as a sustainable source of energy. Endorsing current strategies to harvest energy from marine plastic wastes that enhance power generation technologies will help in building a more sustainable and greener environment that imparts a healthy and circular economy while shielding natural resources.

Design and operation of a packed pilot scale distillation column for tire pyrolysis oil: Towards the recovery of value-added raw materials

This work describes the key features involved in the design and operation of a pilot scale distillation column for the recovery of value-added products from tire pyrolysis oil (TPO), as part of the BLACKCYCLE project. The distillation unit was designed using engineering heuristic rules, simulated distillation (SimDist) data and Aspen Hysys ® modeling. The distillation plant consists of a packed column with a nominal throughput of 20 kg/h, and is classified at the fifth technology readiness level (TRL-5). The commissioning and results of long-term experimental campaigns for validation purposes are also presented. In this way, important information is gathered for the design of larger plants. The distillation unit was tested and validated using TPO produced from a pilot scale continuous single-auger pyrolysis plant. A first distillation was performed yielding a heavy fraction (HF-1) with properties suitable for carbon black production, while the light fraction (LF-1) includes the presence of value-added chemicals such as benzene, toluene, ethylbenzene and xylenes (BTEX) and limonene. The LF-1 was also used for a second distillation, producing a stream high in limonene at the bottom (HF-2), and another one high in BTEX compounds at the top (LF-2), which are valuable raw materials for polymer production and petrochemicals, respectively. The key results obtained here are expected to provide an outstanding impetus for the circular economy of complex streams such as end-of-life tires (ELTs) by combining pyrolysis and distillation technologies.

Comparison of the Magnesiothermic Reduction Behavior of Nb2O5 and Ti2Nb10O29

Nb-Ti binary alloys are widely employed as high value-added materials in the manufacture of super heat-resistant alloys, biomaterials, and superconductors. Therefore, there is significant interest to produce Nb-Ti master alloys in a cost-effective manner. In this study, we investigated the magnesiothermic reduction of Nb2O5 and Ti2Nb10O29 over the temperature range of 1073 to 1223 K and comparatively evaluated the reaction outcomes. The reduction product was composed of metal (Nb or Nb-Ti) particles and MgO, which covered the surface of the reduced metal particles. After the reduction reaction, the surface MgO phase was removed by pickling with hydrochloric acid (HCl) to finally recover the Nb metal or Nb-Ti alloy as a pure product. Scanning electron microscopy and X-ray diffraction analyses of the pure Nb metal and Nb-Ti alloy powders revealed that the reduction of both raw materials was successful at temperatures exceeding 1173 K. Reaction kinetics analysis revealed that the activation energy for the reduction of the mixed metal oxide (Ti2Nb10O29) is lower than that of Nb2O5 reduction. This is because of the different reaction mechanism behaviors during reduction and the different thermodynamic stabilities of the precursors.

Simultaneous double membrane electrolysis of sodium sulfate solution and preparation of hydroxide precursor for layered cathode materials

In this paper, a material-oriented metallurgical electrolysis strategy, which is of such characteristics as short process, easy procedure, and nonpollution, is proposed to treat sodium sulfate wastewater and simultaneously prepare high value-added cathode material LiNi1/3Co1/3Mn1/3O2 for lithium-ion batteries. The strategy is divided into two parts. First, the Ni1/3Co1/3Mn1/3(OH)2 precursor is obtained by double membrane electrolyzing a mixed solution of Na2SO4, NiSO4, CoSO4, and MnSO4 under the optimum electrolysis conditions (60 °C, 1.0 A). Furthermore, LiNi1/3Co1/3Mn1/3O2 cathode is obtained through solid-sintering desulfurization. The change of sulfur content in the process and its effect on the morphology and electrochemical properties of the materials are investigated. Under optimum desulfurization conditions, the LiNi1/3Co1/3Mn1/3O2 electrode delivers a high initial specific discharge capacity of 195.0 mAh·g−1 and a satisfying capacity retention of 85.0% after 120 cycles at 0.1 C in 2.5–4.5 V. This innovative strategy can realize the comprehensive utilization of sodium sulfate wastewater for preparation of Ni, Co, Mn-contained layered cathode materials.

Recent Advances of Lignin Functionalization for High-Performance and Advanced Functional Rubber Composites.

The biomass lignin is the only large-volume renewable feedstock that is composed of aromatics but has been largely underutilized and is sought for valorization as a value-added material. Recent research has highlighted lignin as a promising alternative to traditional petrol-based reinforcements and functional additives for rubber composites. This review summarized the recent advances in the functionalization of lignin for a variety of rubber composites, as well as the compounding techniques for effectively dispersing lignin within the rubber matrix. Significant progress has been achieved in the development of high-performance and advanced functional rubber/lignin composites through carefully designing the structure of lignin-based additives and the optimization of interfacial morphologies. This Review discussed the effect of lignin on composite properties, including mechanical reinforcement, dynamic properties, antiaging performance, and oil resistance, and also the advanced stimuli-responsive performance in detail. A critical analysis for the future development of rubber/lignin composites is presented as concluding remarks.

Conversion of recycled sludge waste into high value-added ceramics as engineering construction materials: Fabrication, characterization and performance evaluation

Sludge from municipal wastewater treatment plants usually exhibits extremely homologous traits with clay in both mineralogical component and chemical composition, and accordingly it can be utilized as an alternative feedstock for clay to fabricate engineering construction materials and advance sludge valorization. In this work, different proportions of wastewater treatment plant sludge (WTPS) were incorporated into kaolin to develop value-added construction ceramic materials. The thermal behavior, crystalline composition, physicochemical performance, microscopic characteristics and sintering mechanism of value-added ceramics were investigated. The results showed that WTPS not only contained a large amount of inorganic components such as SiO2, Al2O3 and Fe2O3, but also rich organic compounds, which contributed to the formation of pore structure inside the ceramics during sintering. Different WTPS addition did not affect the types of crystalline components in sintered ceramics, but markedly impacted the sintering behavior. Only when the WTPS dosage reached 40 wt%, the original mixtures would be fully sintered into construction ceramics with the apparent porosity of 11.30 %, thermal conductivity of 0.50 W/(m·K), bulk density of 2.22 g/cm3, linear shrinkage and volume shrinkage of 14.95 % and 38.86 % respectively, as well as vastly low water absorption (0.58 %) and excellent flexural strength (84 MPa). However, with the WTPS content up to 50 wt%, the flexural strength of sintered ceramics was reduced to 50 MPa, despite the elevated sintering degree, which was related to the high formation of liquid phase and the violent expansion of several closed pores. Therefore, converting WTPS into high value-added construction ceramic products is an operable and beneficial way to achieve sludge waste recycling, reduction and stability.

Novel Porous Organic Polymer Catalyst with Phosphate and Sulfonic Acid Sites for Facile Esterification of Levulinic Acid.

Biomass-derived value-added materials such as levulinic acid (LA) are favorable natural resources for producing ester-based biolubricants owing to their biodegradability, nontoxicity, and excellent metal-adhering properties. However, highly active catalysts must be developed to carry out efficient esterification of LA with aliphatic alcohols, especially long-chain aliphatic alcohols. In this study, we developed a novel porous covalent organic polymer catalyst (BPOP-SO3H) with dual acid sites, phosphate and sulfonic acid sites, for the esterification of LA. The prepared BPOP-SO3H catalyst was verified using various surface analysis techniques. BPOP-SO3H exhibited 98% LA conversion with n-butanol and 99% selectivity for butyl levulinate ester within 30 min, which is superior to that of most reported catalysts. BPOP-SO3H also showed high LA conversion and ester selectivity when other aliphatic alcohols were used. Moreover, BPOP-SO3H showed good recyclability for five consecutive cycles. We believe that incorporating a high density of acid sites into a porous polymer with a large surface area and hierarchical pores is a promising approach for developing heterogeneous acid catalysts for the production of alkyl levulinate esters from LA.

Facile Synthesis of a Highly Value-Added High-Performance Carbon Material from Waste Masks for Advanced Supercapacitors

Facile Synthesis of a Highly Value-Added High-Performance Carbon Material from Waste Masks for Advanced Supercapacitors

Recent advances in high value-added carbon materials prepared from carbon dioxide for energy storage applications

Since the industrial revolution, the consumption of fossil fuels has increased year by year, which has resulted in increasing greenhouse gas emissions. Carbon capture, utilization and storage technology has received extensive attention as a technology for converting atmospheric carbon dioxide into high value-added materials. Carbon materials, as ideal materials for various energy storage devices, have attracted extensive research. Therefore, the selective reduction of CO2 to carbon materials with high added value is a promising solution, which can not only effectively alleviate the greenhouse effect, but also promote the development of the energy storage field. This review introduces the research work of high-value conversion of carbon dioxide into carbon materials and its impact on the performance of energy storage devices in recent years. In particular, we emphasize the reaction processes during CO2 conversion, which can build an understanding of the science and technology involved in the control of interfacial properties, microstructure, and pore structure of CO2-converted carbon nanomaterials. We also summarized the basic design principles for the application of carbon nanomaterials in the field of energy storage. The effect of the microstructure and interface properties of carbon materials converted from CO2 on the energy storage performance are further analyzed. Finally, prospects and discussions are made on the challenges of future development.

Wet Oxidation of Pharmaceutical Sludge for the Treatment and Production of Value-Added Materials

The wet oxidation of pharmaceutical sludge for the treatment and production of value-added materials was investigated. The experiments were carried out in a stainless-steel autoclave reactor with chemical synthetic pharmaceutical sludge. The highest removal rate of total suspended solids (90.1%) and volatile suspended solids (98.4%) was achieved at 260 °C for 60 min with an initial oxygen pressure of 0.8 MPa. Simultaneously, the total chemical oxygen demand removal rate (78.7%) and the soluble chemical oxygen demand removal rate (81.6%) were obtained. The volatile fatty acid concentration—including acetic acid, propanoic acid, isobutyric acid and isovaleric acid—increased to 4819 mg/L with pH 12.56, which indicated the possibility of improving the quality of wet oxidized sludge solution as a potential carbon source by adding reagents. Scanning electron microscopy images showed that the sludge became a loose porous structure after wet oxidation, which is beneficial for dewatering performance. Energy dispersive spectroscopy images illustrate that carbon elements in sludge migrate from solid to liquid phases during the wet oxidation process. These results provide meaningful data for the design of further works and demonstrate that wet oxidation is a promising method for the treatment of pharmaceutical sludge, and the produced volatile fatty acids, including acetic acid and propanoic acid, are potential carbon sources for the biological treatment of wastewater.