S-doped Porous Carbon Research Articles

Efficient selective adsorption of Cr(VI) by S-doped porous carbon prepared from industrial lignin: Waste increment and wastewater treatment

Industrial lignin is a waste product of the paper industry, which contains a large amount of oxygen group structure, and can be used to treat industrial wastewater containing Cr(VI). However, lignin has very low reactivity, so how to enhance its adsorption performance is a major challenge at present. In this study, a two-stage hydrothermal and activation strategy was used to activate the lignin activity and doping S element to prepare high-performance S-doped lignin-based polyporous carbon (S-LPC). The results show that the surface of S-LPC is rich in S and O groups and has a well-developed pore structure, which is very beneficial to Cr(VI) uptake -reduction and mass transfer on the material. In the wastewater, the utmost adsorption potential of Cr(VI) by S-LPC achieved 882.83 mg/g. After 7 cycles of regeneration, the adsorption of S-LPC decreased by only approximately 18 %. Ion competition experiments showed that S-LPC has excellent specificity for Cr(VI) adsorption. In factory wastewater, the adsorption performance of S-LPC for Cr(VI) remained above 95 %, which shows the excellent performance of S-LPC in practical applications. The results are of great significance for green chemical utilization of waste lignin, treatment of industrial wastewater and sustainable development.

Synthesis of Composite Photocatalyst Derived from Medical Mask Waste/TiO2 for Degradation of Rhodamine-B Textile Waste

Abstract The Covid-19 case requires the use of masks followed by an increase in the amount of waste in Indonesia. Another type of waste that continues to increase and is harmful to waters is Rhodamine-B (RhB). One way to treat this waste is by photodegradation method. In this research, the synthesis of S-doped porous carbon (SDPC) derived from medical mask waste was composited with TiO2, a semiconductor material, to be used as photocatalyst material. The aim of this research is to determine the effect of SDPC mass on the structure and morphology of the SDPC/TiO2 composite and the performance of Rhodamine-B degradation. The mass variations of SDPC used were 25%; 37.5%; and 50%. The process of synthesizing porous carbon by sulfonation method at a temperature of 200 °C for 6 hours and continued activation using KOH to form activated SDPC. Then the composite synthesis process was carried out by sonification process. The result show 50% SDPC/TiO2 composite has the best degradation performance with degradation percentage of 54.21% in 2 hours of irradiation time.

Synthesis of S-doped porous carbon/MnO2 composite from discarded medical masks for hybrid supercapacitor electrodes

Abstract The fabrication of supercapacitor electrodes can be obtained from materials with abundant carbon availability such as discarded polypropylene medical masks, studied by XRD, SEM, and FTIR. In this work, discarded surgical masks and then carbon was obtained via a solvothermal method. The fabrication of high performance supercapacitor to enhance the electrochemical performance of carbon-based electrode is by combining carbon material with MnO2 to form hybrid supercapacitor electrodes. The electrochemical performance can be greatly improved because of the high electrical conductivity of carbon and excellent redox reaction from MnO2. Fibrous structure of S-doped porous carbon morphology via SEM with nanowire MnO2 covered a rod carbon structure. Furthermore, XRD analysis and FTIR show the amorphous structure with high peak at 2θ 25.5⁰ and 42.2° with the absorption peak at 509.05 cm−1, 510.68 cm−1 and 578. 87 cm−1 shows the Mn-O stretching. The as-prepared 0.3-SDPC/MnO2 exhibited the highest specific capacitance of 84.71 F g−1. Moreover, as-prepared 0.3-SDPC/MnO2 showed high energy and power density (7.53 Wh kg−1, 169.96 W kg−1) and the lowest resistance of 0.72 Ω. These results indicate that 0.3-SDPC/MnO2 composite electrode will have potential application in hybrid supercapacitors.

Biomass-derived sulfur-doped porous carbon for CO2 and CH4 selective adsorption

Series of sulfur-doped porous carbons were prepared by using glucose as carbon source and sodium dodecyl sulfate as sulfur source to synthesize sulfur-based carbon precursor and KOH as activator. Pore structure parameters and sulfur content of the prepared carbon materials could be facility regulated by controlling the ratio of KOH/sulfur-based carbon precursor and activation temperature, and their adsorptive separation properties towards CO2 and CH4 were investigated. Results showed that the higher the ultra-microporous volume and the S content of the prepared sulfur-doped porous carbon were, the larger the CO2 and the CH4 adsorption capacity were. The maximum adsorption capacity of CO2 (6.54 mmol/g, 273.15 K and 101 kPa, hereinafter) and CH4 (2.98 mmol/g), and the excellent selectivity of CO2/N2 (75.7) and CH4/N2 (22.8) were achieved by ACS-700-2 because of its higher ultra-microporous pore volume and the highest S content. Permeation experiment, cycle stability test and adsorption thermodynamics experiment show that the prepared S-doped porous carbon had good application potential in the separation and enrichment of CO2 in flue gas and CH4 in coalbed methane. In addition, the pore formation mechanism of sulfur-doped porous carbon was discussed.

Fast and efficient reduction of nitroaromatic compounds with copper oxides supported nitrogen-sulfur Co-doped porous carbon material derived metal-organic framework

The expansion of heteroatom-doped carbons with metal-organic frameworks (MOFs) as precursors under heat treatment has attracted extensive attention for the betterment of the catalytic attributes of carbon-based catalysts. After simply pyrolyzing metal-organic framework (MOF) mixed with thiourea (CH4N2S) particles, N and S-doped porous carbon substrates with favorable structural and compositional properties are obtained. The as-synthesized material, which is named CuxO@CNS-400 acts as a heterogeneous catalyst in the reduction reaction of nitro-aromatic compounds, which has superior performance with high activity. The morphology, structure, and physicochemical properties of CuxO@NSC-400 were successfully synthesized and characterized using XRD, TEM, TGA, FE-SEM, EDX, FT-IR, and Raman. In particular, CuxO@CNS-400, obtained by pyrolysis at 400 °C, demonstrates excellent catalytic efficiency of 98 % and high catalytic cycling stability for rapid and highly efficient nitro aromatics reduction.

SiC and N, S-doped carbon nanosheets and lignin-enhanced organohydrogel for low-temperature tolerant solid-state supercapacitors

The rational design of porous carbon materials and hydrogel electrolytes with excellent mechanical properties and low-temperature tolerance are significance for the development of flexible solid-state supercapacitors. In this study, we introduce a novel methodology for synthesizing SiC/N, S-doped porous carbon nanosheets from bamboo pulp red liquor (RL). We leverage the SiO2 and the sodium salt in RL as templates and sodium lignosulfonate as sulfur dopants for the pyrolysis process and use NH4Cl as a nitrogen dopant. This innovative approach results in a material with a remarkable specific surface area of 1659.19 m2 g−1, a specific capacitance of 308 F g−1 at a current density of 1 A g−1 and excellent stability. Additionally, we harness alkali lignin extracted from RL to enhance a poly (vinyl alcohol) (PVA) matrix, creating a gel electrolyte with low-temperature tolerance and outstanding mechanical properties. A flexible solid-state supercapacitor, which incorporates our electrodes and gel electrolyte, demonstrates high energy density (5.2 W h kg−1 at 251 W kg−1 power density). Impressively, it maintains 82 % of its capacitance over 10,000 cycles of charge and discharge. This provides a new solution for the development of flexible solid-state supercapacitors.

Sulfur-Doped porous carbon Adsorbent: A promising solution for effective and selective CO2 capture

The effective and selective capture of CO2 through the rational design of microstructures and the synthesis of carbon materials with enriched surface functionality is of utmost importance in mitigating CO2 emissions. In this study, we successfully prepared a novel type of S-doped porous carbon material with a high surface area and a significant volume of micropores in a straightforward manner. This was achieved by pyrolyzing carbonized coconut shells (CS) with potassium thiosulfate K2S2O3 (PT) as an activating and sulfur supply agent. By adjusting the pyrolysis temperature within the range of 650–750 °C, we obtained carbon materials with varying surface areas (887–1924 m2/g), pore volumes (0.35–0.95 cm3 g−1), and a homogeneous distribution of sulfur content (up to 12.26 wt%) within the carbon framework. The optimal S-doped porous carbon demonstrated the adsorption capacities of 3.59 mmol g−1 at 25 °C and 5.31 mmol g−1 at 0 °C under 1 bar. Additionally, the prepared sorbent exhibited favorable CO2/N2 selectivity, high isosteric heat, and stable cycling performance. These excellent CO2 capture properties can be attributed to the materials' high microporosity and well-dispersed sulfur functionality in the carbon framework. Collectively, these findings highlight the potential of these novel carbon materials with heteroatom doping as efficient adsorbents for the selective capture of CO2, presenting a viable solution in the quest for effective CO2 mitigation.

Gas exfoliation induced N, S-doped porous 2D carbon nanosheets for effective removal of copper ions by capacitive deionization

Using capacitive deionization to remove heavy metal ions from water has received much attention, but the inferior salt adsorption capacity (SAC) of electrode materials has always limited its practical application. Herein, N, S co-doped two-dimensional (2D) porous glucose derived carbon nanosheets (NSPGC) was successfully fabricated, utilizing the gas exfoliation by calcination of thiourea. The NSPGC demonstrates distinct 2D lamellas, high specific surface area (2529 m2 g−1), hierarchical pore structure and high wettability. In electrochemical tests, a high specific capacitance (127 F g−1) and electrons/ions transport performance can be achieved in the NSPGC, moreover it showed a prominent SAC of 206.57 mg g−1 and recoverability in 100 mg L−1 CuSO4 solution. Moreover, the density functional theory (DFT) calculation manifested the intrinsic affinity of Cu2+ improved by N, S co-doping, which played an essential role in enhancing the Cu2+ removal performance of CDI. Our work provided a new insight into the preparation of high-performance CDI electrode materials for Cu2+ removal and promoted the application of CDI in heavy metal wastewater.

One-pot synthesis of self S-doped porous carbon for efficient CO2 adsorption

Considering the rising environmental and efficiency concerns, the development of porous carbon via a surface decoration approach has received great attention for selectively adsorb CO2 from the flue gas. Herein, self-S-doped porous carbon was prepared from petroleum coke with high sulfur content (PHS) utilizing KOH as an activating agent. The effect of the activating temperatures and the KOH/PHS mass ratio on the physical feature and CO2 uptake performance of the as-synthesis porous carbons was fully examined. The optimal sample (PHS-650-3) presents the specific BET surface area and total pore volume of 1278 m2/g and 0.56 cm3/g, respectively. The PHS-650-3 sample displayed the maximum CO2 adsorption capacity of 4.18 and 5.57 mmol g−1 at 25 and 0 °C and 1 bar thanks to its enhanced textural characteristics and high amount of sulfur functionality on the surface. Last but not least, the as-synthesized S-doped porous carbon shows ideal adsorption solution theory (IAST) CO2/N2 selectivity of 21, fast adsorption kinetics, suitable heat of adsorption value and stable uptake capacity upon consecutive adsorption cycles, claiming its readily potential CO2 adsorption applications.

Self-generated FeSe2 and CoSe2 nanoparticles confined in N, S-doped porous carbon as efficient and stable electrocatalyst for oxygen evolution reaction

Transition metal selenides embedded into a nitrogen, sulfur co-doped carbon materials (TMS@NSC) are promising electrocatalysts to effectively address the sluggish kinetics of oxygen evolution reaction (OER). However, the OER catalytic activity of single metal TMS@NSC is still limited by insufficient active sites. Hence, FeSe2 and CoSe2 nanoparticles self-generated and confined in N, S-doped porous carbon (FeSe2/CoSe2@NSC) catalyst has been synthesized by in-situ polymerization and the subsequent low temperature selenization strategy, aiming to increase the active sites of TMS@NSC. The hybridized FeSe2/CoSe2@NSC catalyst has excellent OER catalytic activity and good durability in alkaline media, which only requiring an overpotential as low as 278 mV to drive a current density of 10 mA cm−2, outperforming most recently reported selenide catalysts and commercial RuO2 catalysts. The high catalytic activity of FeSe2/CoSe2@NSC catalyst is attributed to the rapid electron transfer between FeSe2 and CoSe2 in the unique N, S-doped graphene nanosheets, which effectively inhibits the aggregation of nanoparticles, fully exposes the active sites and provides pathway for oxygen release during the OER process. Moreover, the overall water splitting device assembled with FeSe2/CoSe2@NSC catalyst showed low overpotential of 1.57 V. This study provides a feasible strategy for the design of high active and stable TMS@NSC catalysts for OER and other energy conversion applications.

Self-Activating Approach for Synthesis of 2,6-Naphthalene Disulfonate Acid Disodium Salt-Derived Porous Carbon and CO2 Capture Performance

Porous carbon is considered an effective adsorbent for CO2 uptake thanks to its high textural feature, tunable surface decoration, and stable chemical/physical characteristics. Herein, a one-pot self-activating synthesis approach has been introduced to fabricate disodium 2,6-naphthalene disulfonate (NDS)-derived self-S-doped porous carbon. With this method, there is no external chemical activating agents for the activation process, and the self-activating process occurs by releasing CO, H2O, and CO2 gases during pyrolysis treatment. It was found that activating temperatures can carefully control the porous textural and elemental compositions of the as-prepared carbons. Upon the activating process, the optimal S-doped porous carbon was prepared at 700 °C, providing CO2 uptake capacities of 2.36 and 3.56 mmol/g at 25 and 0 °C and 1 bar, respectively. An in-depth investigation indicates that the joint effect of narrow microporosity and S content determines the CO2 uptake for this series of carbons. In addition, these NDS-derived self-S-doped porous carbons exhibit moderate CO2 heats of adsorption, fast adsorption kinetics, reasonable CO2/N2 selectivities, good dynamic CO2 capture capacities, and stable recyclabilities. The presented synthesis method is promising for fabricating facile carbon-based adsorbents from various organic precursors.

Sulfur-Bridged Bonds Heightened Na-Storage Properties in MnS Nanocubes Encapsulated by S-Doped Carbon Matrix Synthesized via Solvent-Free Tactics for High-Performance Hybrid Sodium Ion Capacitors.

The exploitation of electrode materials with ability to balance capacity and kinetics between cathode and anode is a challenge for sodium-ion hybrid capacitors (SIHCs). Mn-based anode materials are limited by poor electrical conductivity, sluggish reaction kinetics, large volume variation, weak cycling stability, and inferior reversible capacity. Herein, MnS nanocubes encapsulated in S-doped porous carbon matrix (MSC) with strong sulfur-bridged bond interactions (CSMn) are successfully synthesized by solvent-free tactics. The CSMn bonds generated between MnS and carbon significantly inhibit the aggregation of nanostructural MnS cubes, restrict the volume expansion, and stabilize the nanostructure, which improves the Na+ storage reversibility and stability. Moreover, S-doped porous carbon enhances the electrical conductivity and electrons/ions diffusion rate, which boosts a fast kinetic reaction. As expected, MSC anode presents an outstanding reversible capacity of 600 mAh g-1 at 0.2 A g-1 and a long-term stable capacity of 357 mAh g-1 for 1000 cycles at a high current density of 10 A g-1 in sodium-ion batteries (SIBs). The as-assembled SIHCs delivera high energy density of 109W h kg-1 and a high power output of 98W kg-1 , with 88% capacity retention at 2 A g-1 after 2000 cycles and practical applications (55 LEDs can be lighted for 10 min).

S-doped porous carbon fibers with superior electrode behaviors in lithium ion batteries and fuel cells

The orientation construction of S-doped porous carbon fibers (SPCFs) is realized by the facile template-directed methodology using asphalt powder as carbon source. The unique fiber-like morphology without destruction can be well duplicated from the template by the developed methodology. MgSO 4 fibers serve as both templates and S dopant, realizing the in-situ S doping into carbon frameworks. The effects of different reaction temperatures on the yield and S doping level of SPCFs are investigated. The S doping can not only significantly enhance the electrical conductivity, but also introduce more defects or disorders. As anode material for lithium ion batteries (LIBs), SPCFs electrode delivers better rate capability than undoped PCFs. And the capacity of SPCFs electrode retains around 90% after 300 cycles at 2 A g −1 , exhibiting good cycling stability. As the electrocatalysts for fuel cells, the onset potentials of SPCFs obtained at 800 and 900 °C are concentrated at 0.863 V, and the higher kinetic current densities at 0.4 V of them are larger than that of PCFs, demonstrating the superior electrocatalytic performance. Due to the synergistic effect of abundant pore channels and S doping, SPCFs electrode exhibits superior electrochemical performances as anode for LIBs and elecctrocatalyst for fuel cells, respectively. Additionally, the oriented conversion of asphalt powder into high-performance electrode material in this work provides a new way for the high value application of asphalt.

Green and universal sulfur doping technique coupled with construction of conductive network for enhanced kinetics of Li-ion capacitors

Herein, the integral technology process including the production, doping and tail gas recovery systems is constructed to realize the S doping modification with the excellent universality for arbitrary carbon materials. S-doped porous carbon (SPC) and S-doped carbon nanotubes (SCNTs) obtained by the developed doping methodology are employed as anode material and conductive additives of cathode and anode in lithium ion capacitor (LIC), respectively. The great alleviation of the kinetics mismatch between cathode and anode in LIC is benefited from S doping modification on anode and the construction of efficient conductive network inside electrodes. Besides, the excellent rate capability and durability can still be afforded by the fabricated LIC even at low temperature environment. This work not only develops a scalable, green and universal S doping methodology for arbitrary carbon materials, but also provides a reasonable design for the construction of high-performance LIC device.

Embedding FeS nanodots into carbon nanosheets to improve the electrochemical performance of anode in potassium ion batteries

Potassium-ion batteries (PIBs) is one of the most promising alternatives for Lithium-ion batteries (LIBs) due to the low-cost and abundant potassium reserves. However, the electrochemical performances of PIBs were seriously hindered by the larger radius of potassium ions, resulting in a slow kinetic during the electrochemical reaction, especially in the PIB anodes. In the study, we propose FeS nanodots embedded S-doped porous carbon (FeS@SPC) synthesized by a simple self-template method for the storage of potassium-ions. The FeS nanodots with an average diameter of 5 nm are uniformly distributed in S-doped porous carbon nanosheets. When the FeS@SPC was used as the anode in PIBs, the unique structure of FeS@SPC can relieve the agglomeration and volume expansion of FeS effectively during the charge–discharge process. Even after 3000 cycles, the FeS nanodots are still uniformly embedded in porous carbon without agglomeration. Ascribed to the merits, the FeS@SPC exhibits a reversible capacity of 309 mAh g−1 at 0.1 A g−1 after 100 cycles and 232 mAh g−1 at 1 A g−1 after 3000 cycles. The excellent electrochemical performance of FeS@SPC is attributed to the synergistic effects of FeS nanodots and S-doped porous carbon, which facilitated the diffusion of electrolyte and accelerated the migration of potassium ions. Moreover, theoretical calculation results also suggest that the van der waals heterostructure of FeS@SPC displays higher adsorption energy for potassium ions than that of S-doped graphene, indicating the suitability of FeS@SPC for K storage.

Transforming waste polypropylene face masks into S-doped porous carbon as the cathode electrode for supercapacitors.

The spread of COVID-19 has led to an explosive increase in the number of waste polypropylene face masks worldwide, landfill and incineration of which will cause serious pollution and resource waste. This study aims to develop a new method for the safe and high-added value reuse of materials for polypropylene face masks based on carbonization of porous polymer. The waste masks were first sulfonated in an autoclave, then used as carbon source and turned into a dense hollow fiber porous structure after a one-step heat treatment. This porous structure has a high specific capacitance, namely 328.9 F g−1 at a current density of 1 A g−1. Besides, the assembled solid-state capacitor possesses a good energy density of 10.4 W h kg−1 at a power density of 600 W kg−1, and excellent cycling stability with a capacitance retention rate of 81.1% after 3000 cycles. These findings indicate that the novel carbonization technology in this study can not only be used to obtain high-performance supercapacitor electrode materials but also provide a new idea for the recycling and utilization of wastes such as medical devices.

Bimetallic Fe-Mo sulfide/carbon nanocomposites derived from phosphomolybdic acid encapsulated MOF for efficient hydrogen generation

To tackle the energy crisis and achieve more sustainable development, hydrogen as a clean and renewable energy resource has attracted great interest. Searching for cheap but efficient catalysts for hydrogen production from water splitting is urgently needed. In this report, bimetallic Fe-Mo sulfide/carbon nanocomposites that derived from a polyoxometalate phosphomolybdic acid encapsulated metal-organic framework MIL-100 (PMA@MIL-100) have been generated and their applications in electrocatalytic hydrogen generation were explored. The PMA@MIL-100 precursor is formed via a simple one-pot hydrothermal synthesis method and the bimetallic Fe-Mo sulfide/carbon nanocomposites were obtained by chemical vapor sulfurization of PMA@MIL-100 at high temperatures. The nanocomposite samples were fully characterized by a series of techniques including X-ray diffraction, Fourier-transform infrared analysis, thermogravimetric analysis, N2 gas sorption, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and were further investigated as electrocatalysts for hydrogen production from water splitting. The hydrogen production activity of the best performed bimetallic Fe-Mo sulfide/carbon nanocomposite exhibits an overpotential of -0.321 V at 10 mA cm−2 and a Tafel slope of 62 mV dec-1 with a 53 % reduction in overpotential compared to Mo-free counterpart composite. This dramatic improvement in catalytic performance of the Fe-Mo sulfide/carbon composite is attributed to the homogeneous distribution of the nanosized iron sulfide, MoS2 particles, and the formation of Fe-Mo-S phases in the S-doped porous carbon matrix. This work has demonstrated a potential approach to fabricate complex heterogeneous catalytic materials for different applications.

Self-templated synthesis of porous carbon with different sulfur content derived from polyethersulfone matrix for supercapacitor and dyes adsorption

Different sulfur-doped content carbon is fabricated by the carbonization of SSNa modified PES, the pores and abundant heteroatoms endow the S-doped porous carbon (C-3) with a high capacity of 172 F/ g at 1 A/g and good cycling life (98.5 % retention after 6000 cycles). Moreover, typical dye of methylene blue adsorption results exhibited the maximum adsorption capacity of sulfur-doped carbon (C-3) was approximately 78 mg/g. The enhanced electrochemical performance of C-3 is ascribed to the sulfur-doping and ellipsoid structure. The results pave a new way to fabricate controlled heteroatom-doped content carbon material for supercapacitors and dyes adsorption through the cross linking heteroatom-containing polymer.

Sulfur-doped porous carbon as high-capacity anodes for lithium and sodium ions batteries

S-doped porous carbon (S/C) has been successfully fabricated from biomass waste (drug residue). The S/C not only has a unique porous structure and channel, but porous structures are interconnected to form a sponge-like structures. The unique structure not only increases the specific surface area and energy storage sites, but also shortens the path of ion transmission and charge transfer. When S/C-1 is used as lithium ion batteries (LIBs) anode, the capacity of 710 mAh g−1 can be achieved after 50 cycles at 0.1 A g−1. The capacity still has 364 mAh g−1 at 5 A g−1 for long-life-cycle. For sodium ion batteries (SIBs), a capacity of 518 mAh g−1 can be delivered at 0.1 A g−1 for 50 cycles, and a capacity of long-life-cycle at 5 A g−1 still maintains 230 mAh g−1. The improving rate capacities of S/C-1 can be attributed to the short diffusion lengths of Li+ and Na+ ions for uniform sponge-like structure, large specific surface area (SSA) and additional active sites. This work has an important opportunity to change the current energy situation.

Sustainable self-powered electro-Fenton degradation using N, S co-doped porous carbon catalyst fabricated with adsorption-pyrolysis-doping strategy

Abstract A chief challenge of employing self-powered electro-Fenton (EF) system for drastically degrading stubborn pollutants in industrial wastewater is to develop the catalysts with high activity and selectivity in 2e− oxygen reduction and the controllable output power of triboelectric nanogenerator system for collecting ambient available and renewable mechanical energy. Herein, we propose the adsorption-pyrolysis-doping strategy to tailor the content of C–S–C/S–C species and pore sizes of biomass-derived N, S-doped porous carbon catalyst from populus tomentosa to achieve the activity and selectivity of H2O2 electrosynthesis and develop a 3D printed revolving roller-compacted triboelectric nanogenerator (RRC-TENG) as an electric supply with instantaneous short circuit current of 285 μA, open circuit voltage of 500 V, transferred charge of 1.32 μC, and the optimum output power density of 3.0 W m−2, to self-power EF degradation of resistant mixed basic dyes (MB, MO and MG), whose decolorization efficiency is up to 97.8% within 45 min. This work not only realizes the controllable synthesis of high value‐added carbon catalysts via adsorption-pyrolysis-doping strategy, but also advances the EF system with a direction to develop the sustainable self-powered degradation by RRC-TENG replacing the traditional power sources, which makes for massively treating industrial wastewater with high-concentration wastes.