Coal Gasification Wastewater Research Articles

Enhanced performance of anaerobic two-phase reactor treating coal gasification wastewater with the assistance of zero valent iron under co-digestion conditions

Coal gasification wastewater (CGW) is a typical industrial wastewater that is difficult to degrade as it contains a large number of refractory and toxic pollutants, such as high concentrations of phenols.The aim of this study is to investigate an anaerobic two-phase reactor treating synthetic CGW under co-digestion conditions. The optimum dosages of co-substrate (glucose = 1000 mg/L), zero valent iron (ZVI) (2 g/L), and hydrolysis acidification time (12 h) were explored by batch tests. The results indicated that the concentration of total phenols declined from 636 mg/L to 376 mg/L when the cumulative methane production increased to 145 mL. In the long-term operation of the anaerobic two-phase reactor, 1,000 mg/L glucose was added to the influent, and 2 g/L ZVI was added in the methanogenic phase, respectively. HRTs in acidogenic and methanogenic phases were kept at 12 h and 48 h, respectively. The average acetate and TVFAs concentrations remained at approximately 852 mg/L and 1042 mg/L, respectively. The result showed that the concentrations of influent and effluent COD were approximately 3,191 mg/L and 412 mg/L, respectively, while those of influent and effluent total phenols were approximately 655 mg/L and 23 mg/L, respectively. The removal efficiencies of total COD and total phenols were over 86% and 96%, respectively. In addition, the total methane production rose to 250 mL/d. Microbial community structure analysis demonstrated that the acidogenic phase contained most types of microbial species and the most complex community diversity in the anaerobic system and that direct interspecies electron transfer (DIET) might occur between the potential electroactive bacteria Chloroflexi and the archaea Methanobacteriales and Methanosaeta, respectively.

Advanced treatment of coal gasification wastewater by O3/Fenton in a rotating packed bed in tandem with coagulation

In this study, the O3/Fenton system in a rotating packed bed (RPB) in tandem with coagulation process was applied to the advanced treatment of coal gasification wastewater (CGW). The removal of COD reached 35.4% in the O3/Fenton@RPB process, and the total removal of COD rose to 47.8% after the effluent of the O3/Fenton@RPB process was further treated with coagulation. The O3/Fenton@RPB + coagulation tandem process also demonstrates good effect on enhancing biodegradation and removing color of the CGW, with the BOD5/COD and decolorization in the tandem process reaching 0.49 and 87.5%, respectively. In addition, an artificial neural network model was established to predict the mass transfer performance of the O3/Fenton system in the RPB and exhibited a good predictability. The O3/Fenton@RPB + coagulation tandem process shows the application potential in the advanced treatment of CGW.

Binary TiO2/RGO photocatalyst for enhanced degradation of phenol and its application in underground coal gasification wastewater treatment

In this work, we synthesized the TiO2/reduced graphene oxide (TiO2/RGO) binary nanohybrids through the sol-anaerobic calcination method, the TiO2 nanoparticles belonging to anatase type were evenly loaded on RGO surface in the form of Ti–O–C bond. The enhanced photocatalytic performance can be ascribed to the existence of RGO that can effectively promote the transfer of photo-induced electron-hole pairs to generate more hydroxyl radicals (·OH) and superoxide anion (O2·-) degrading phenol. The TiO2/RGO nanocomposite with weight ratio of RGO to TiO2 (37.0%–55.7%) had achieved maximum degradation of phenol from aqueous solution, and about 97.87% of phenol had been removed within 180 min under UV-light illumination. Through GC-MS tracking of phenol degradation process, it can be observed that long-chain intermediates will be generated, and these intermediates will eventually be degraded, confirming that phenol can be completely removed. Additionally, around 67% TOC of simulated underground coal gasification (UCG) wastewater can be removed after 10 h degradation using TiO2/RGO binary composites as photocatalysts. All these results demonstrate that the binary nanohybrids possess great potential for the organic contaminants destruction from the actual coal chemical wastewater.

Degradation of p-cresol, resorcinol, and phenol in anaerobic membrane bioreactors under saline conditions

Treating petrochemical wastewater is a challenge for conventional anaerobic reactors. One example is coal gasification wastewater that, besides its salinity, is rich in toxic and inhibitory aromatics, such as phenol, cresols, and resorcinol. Studies have shown that phenol and p-cresol share the same degradation intermediates, whereas resorcinol is degraded via another route. This study investigated the simultaneous degradation of p-cresol or resorcinol with phenol under anaerobic saline conditions. Batch experiments with anaerobic phenol-degrading biomass were conducted to assess the feasibility of the degradation of p-cresol and resorcinol. Volumetric uptake rates of 11.4 ± 2.4 mgp-cresol·L–1d–1 and 4.2 ± 1.9 mgresorcinol·L–1d–1 were determined. The effect of p-cresol and resorcinol on the specific methanogenic activity and the cell viability in phenol-degrading and non-adapted biomass was assessed. Half maximal inhibitory concentration (IC50) values of 0.73 gp-cresol·L-1 and 3.00 gresorcinol·L-1 were estimated for phenol-degrading biomass, whereas IC50 values of 0.60 gp-cresol·L-1 and 0.25 gresorcinol·L-1 were estimated for the non-adapted biomass. p-Cresol caused a higher decrease in the non-damaged cell counts in comparison to resorcinol. Two anaerobic membrane bioreactors under saline conditions [8 g Na+·L–1] were fed with mixtures of either phenol-p-cresol or phenol-resorcinol. At an influent phenol concentration of 2 g·L-1, maximum conversion rates of 22 mgp-cresol·gVSS-1d–1 and 16 mgresorcinol·gVSS–1d–1 were found. In both AnMBRs, Syntrophorhabdus sp. and Methanosaeta sp. were the most abundant bacteria and methanogen, respectively. The feasibility of simultaneous conversion of phenolic compounds under saline conditions in AnMBRs opens novel perspectives for the high-rate anaerobic treatment of chemical wastewater.

Roles of coal gasification wastewater in coal electrolysis for hydrogen production

Coal-assisted water electrolysis can reduce the electricity consumption of traditional water electrolysis by 40–60%, but the rate of hydrogen production in this process is very slow. Some coal gasification wastewater can promote the electrical oxidation of coal, the addition of which can achieve resource utilization of wastewater while producing hydrogen at low cost. In this study, the electrolysis characteristics and oxidation mechanism of gas washing water are studied using anode reaction kinetics, and its role in the process of coal electrolysis is studied. The results show that the main anodic reactions of gas washing water are, in order of increasing voltage, the oxidation of organic matter, bromide ions, and the water decomposition reaction, and that there is no obvious interaction between these three oxidation stages and Fe3+/Fe2+. On the one hand, gas washing water can promote the catalysis of iron ions and increase the effective iron concentration in the solution. On the other hand, it plays an important role in changing the surface state of coal particles and improving the electrochemical activity of coal, thereby increasing the reaction rate of coal electrolysis.

Effects of polyurethane foam carrier addition on anoxic/aerobic membrane bioreactor (A/O-MBR) for coal gasification wastewater (CGW) treatment: Performance and microbial community structure

Coal gasification wastewater (CGW) is a typical toxic and refractory industrial wastewater with abundant phenols contained. Two identical anoxic/aerobic membrane bioreactors (with (R2) and without (R1) polyurethane (PU) foam) were carried out in parallel to investigate the role of PU foam addition in enhancing pollutants removal in CGW. Results showed that both systems exhibited effective removal of chemical oxygen demand (>93%) and total phenols (>97%) but poor ammonia nitrogen removal (<35%) constrained by ammonia oxidation process. GC–MS analysis revealed that aromatic and other refractory intermediates were dramatically reduced in R2. Moreover, the PU addition had negligible influence on the total soluble microbial products and extracellular polymeric substances contents but significantly alleviated membrane fouling with the operating time 33% prolonged. Microbial community revealed that Flavobacterium, Holophaga, and Geobacter were enriched on PU. Influent type might be a main driver for microbial community succession.

Simultaneously autotrophic denitrification and organics degradation in low-strength coal gasification wastewater (LSCGW) treatment via microelectrolysis-triggered Fe(II)/Fe(III) cycle

The autotrophic iron-depended denitrification (AIDD), triggered by microelectrolysis, was established in the microelectrolysis-assistant up-flow anaerobic sludge blanket (MEA-UASB) with the purpose of low-strength coal gasification wastewater (LSCGW) treatment while control UASB operated in parallel. The results revealed that chemical oxygen demand (COD) removal efficiency and total nitrogen (TN) removal load at optimum current (2.5 A/m3) in MEA-UASB (83.2 ± 2.6% and 0.220 ± 0.010 kg N/m3·d) were 1.42-fold and 1.57-fold higher than those (58.5 ± 2.1% and 0.139 ± 0.011 kg N/m3·d) in UASB, verifying that AIDD and following dissimilatory iron reduction (DIR) process could offer the novel pathway to solve the electron donor-deficient and traditionally denitrification-infeasible problems. High-throughput 16S rRNA gene pyrosequencing shown that iron-oxidizing denitrifiers (Thiobacillus and Acidovorax species) and iron reducing bacteria (Geothrix and Ignavibacterium speices), acted as microbial iron cycle of contributors, were specially enriched at optimum operating condition. Additionally, the activities of microbial electron transfer chain, electron transporters (complex I, II, III and cytochrome c) and abundance of genes encoding important enzymes (narG, nirK/S, norB and nosZ) were remarkably promoted, suggesting that electron transport and consumption capacities were stimulated during denitrification process. This study could shed light on better understanding about microelectrolysis-triggered AIDD for treatment of refractory LSCGW and further widen its application potential in the future.

Process Design and Economic Analysis of Coal Gasification Wastewater Treatment and Solid Oxide Cells Coupling System

Process Design and Economic Analysis of Coal Gasification Wastewater Treatment and Solid Oxide Cells Coupling System

Study on CO2 gasification properties of coal gasification wastewater slurry

AbstractCoal water slurry technology and gasification technology are used to simultaneously treat wastewater and CO2; coal water slurry is prepared from fixed‐bed coal gasification wastewater; and then, thermogravimetric analysis, Fourier‐transform infrared spectrometry, scanning electron microscopy, energy‐dispersive spectrometry, and X‐ray diffraction are used to analyze the characteristic parameters of CO2 gasification and the products that formed. The results reveal the following: (a) compared with coal water slurry, coal gasification wastewater slurry shows decreases in the gasification start temperature, gasification weight loss peak temperature, and gasification end temperature of 12°C, 22°C, and 17°C, respectively, and shows increases in the maximum and average reaction rates. In addition, the reactivity index for coal gasification wastewater slurry is found to be 14.29% higher than that for ordinary coal water slurry. (b) Coal gasification wastewater slurry produces more methane and other aliphatic hydrocarbon gases in the pyrolysis stage and more CO in the coke gasification stage than coal water slurry. (c) Coal gasification wastewater slurry contains many small particles and flocs on the surface of the coal and a high Na content (up to 8.07%) in the microarea. In addition, a richer pore structure exists on the surface of the gasification residue of the coal gasification wastewater slurry. (d) The components of the gasification residue for coal gasification wastewater slurry show relatively larger changes. Moreover, the catalytic effect of alkali metal may be weakened due to the reaction of the minerals in the coal to form a complex.

Selectively photoelectrocatalytic reduction of oxygen to hydroxyl radical and singlet oxygen: Mechanism and validation in coal wastewater

The fine-tuning of generating hydroxyl radical (OH) and singlet oxygen (1O2) was firstly proposed via the selectively photoelectrochemical (PE) reduction of oxygen with Cu-coordinated carbon-nitride-electrode (CuCN). Complete removal efficiency and trace Cu leaching (<0.01 ppm) were achieved during treatment of dimethyl phthalate and atrazine, which were mainly oxidized by OH and 1O2, respectively. Besides, no toxic intermediates was detected in the whole degradation process. The overall oxygen reduction pathway in PE system was demonstrated by electron paramagnetic resonance measurements and quenching tests. The valence band position of CuCN was designed to be more negative (−1.5 VSHE) for favoring the photocatalytic oxygen reduction. Specifically, Cu-N2-C as active sites optimized the Gibbs free energy of intermediate *OOH (ΔG*OOH = 3.99 eV) to improve the reactivity of two-electron oxygen reduction. The CuCN/photoelectrochemical system is applied for treatment of coal water slurry gasification (CWS) wastewater with high concentration of salt. The TOC of CWS was successfully decreased from 127 to 1.9 mg·L−1 in 3 h with a low specific energy consumption of 0.024−0.05 kW·h·g−1·TOC−1. The treated CWS wastewater can be used for recovery and utilization of salt as chemical raw materials. This work highlights the important role of synergistic photo-electro-catalytic effect in regulating the generation of active oxygen species via oxygen reduction pathway, which can be a promising way especially for salinity coal wastewater remediation.

Removal of Solid Impurities from Coal Gasification Wastewater by Sand Filtration

Coal gasification wastewater has complex pollutant components and high COD value, and contains a variety of toxic and harmful substances. The treatment of coal gasification wastewater has always been one of the important problems in the development of coal gasification industry in China. In this paper, aiming at the removal of fine particle pollution in coal gasification wastewater, the sand filtration method was used to explore the changes of parameters such as solid content removal, separation accuracy, grade efficiency under the conditions of separating different bed thicknesses. With this separation method, the fine particle pollutants in coal gasification wastewater can be effectively removed by more than 95%, the separation accuracy can reach 0.46 μm. The operation conditions are optimized for further industrial application.

Study on Adsorption Performance of Lignite Activated Carbon for Coal Gasification Wastewater

In order to ensure the excellent adsorption performance, this paper choosed lignite activated carbon to study the adsorption performance of typical pollutants phenol, indole and quinoline in coal gasification wastewater, and analyzed its adsorption performance under single matrix and co-substrate conditions. The experimental results showed that among the three kinds of organic substances, lignite activated coke has the strongest adsorption capacity for phenol, while the adsorption capacity for quinoline was relatively low. Under mixed matrix conditions, activated coke has strong adsorption selectivity for phenol and indole.

Binary TiO 2/RGO Photocatalyst for Enhanced Degradation of Phenol and its Application in Underground Coal Gasification Wastewater Treatment

In this work, we synthesize the TiO2/RGO binary nanohybrids through the sol-anaerobic calcination method, the TiO2 nanoparticles belonging to anatase type were evenly loaded on RGO surface in the form of Ti-O-C bond. The enhanced photocatalytic performance can be ascribed to the existence of RGO that can effectively promote the transfer of photo-induced electron-hole pairs to generate more hydroxyl radicals (·OH) and superoxide anion (O2·-) degrading phenol. The TiO2/RGO nanocomposite with weight ratio of RGO to TiO2 (37.0% to 55.7%) has achieved maximum degradation of phenol from aqueous solution, and about 97.87% of phenol has been removed within 180 min under UV-light illumination. Through GC-MS tracking of phenol degradation process, it can be observed that long-chain intermediates will be generated, and these intermediates will eventually be degraded, confirming that phenol can be completely removed. Additionally, around 67% TOC of simulated underground coal gasification (UCG) wastewater can be removed after 10 h degradation using TiO2/RGO binary composites as photocatalysts. All these results demonstrate that the binary nanohybrids possess great potential for the organic contaminants destruction from the actual coal chemical wastewater.

Enhanced anaerobic co-metabolism of coal gasification wastewater via the assistance of zero-valent iron

Coal gasification wastewater (CGW) contains high-concentration phenols which lead to poor anaerobic biodegradability and low resource utilization. Anaerobic co-substrate can provide abundant electron donor while zero-valent iron (ZVI) can enhance the methanogenesis by promoting electron transfer. Hence, new insights to anaerobic co-metabolism of CGW with the assistance of ZVI were investigated. Batch tests showed that when ZVI dosage was 1.0 g/L and glucose was used as the co-substrate with concentration of 1500 mg COD/L, the COD concentration in CGW decreased from 3644 to 750 mg/L after 6 days anaerobic digestion, obtaining COD removal rate of about 79.4%. The average total phenol (TP) concentration decreased from 509 mg/L on day 1 to almost 0 mg/L on day 3. The cumulative methane production for 6 days was about 245 mL. During the 90-day long-term operation, the average removal rates of COD and total phenol were about 34% respectively and the average methane production was only 13 mL/day with no ZVI addition. However, with the addition of 1 g/L ZVI in the system, the average removal rates of COD and total phenol rose to 65.3% respectively and the average methane production rose to 106.4 mL/day. Furthermore, with the glucose (COD = 1500 mg/L) continued to add in the influent, the average COD and TP removal rates rose to 76.2% and 73.5% respectively and the average methane production promoted to 447.6 mL/day. The Venn analysis indicated that the microbial cultivation method of ZVI and glucose additions can increase the number of microbial species.

Enhanced phenols removal and methane production with the assistance of graphene under anaerobic co-digestion conditions

Coal gasification wastewater (CGW) contains high concentration phenols which lead to poor anaerobic biodegradability and resource utilization. In this paper, new insights to improve synthetic CGW anaerobic degradation with the help of graphene under co-digestion conditions were investigated. Batch tests showed that with the addition of graphene dosage of 10 g/L and glucose as a co-substrate with chemical oxygen demand (COD) concentration of 2000 mg/L, the average COD concentration decreased from 3995 mg/L on day 1 to 983 mg/L on day 12. The average total phenol (TP) concentration decreased from 431 mg/L on day 1 to 23 mg/L on day 12. The cumulative methane production for 12 days was about 200 mL. Long-term experiments showed the average effluent COD and total phenol reached 1137 mg/L and 200 mg/L, respectively. While methane production stabilized at 500 mL/d. In addition, the coenzyme F420 concentration increased from 1.075 μmol/g/VSS to 2.3 μmol/g/VSS. The analysis of microbial community structure indicated that the performance of phenols removal and methane production was related to the main microbial flora. The enriched Clostridium, Pseudomonas and species from Firmicutes and Chloroflexi participated in the stages of hydrolysis and acidogenesis. The electrogens Pseudomonas and archaea Methanosaeta were likely the major groups taking part in the direct interspecies electron transfer (DIET). The results obtained in this paper provide a theoretical basis for high-efficiency anaerobic degradation of CGW in practical engineering applications.

Enhanced anaerobic degradation of quinoline and indole with dried Chlorella pyrenoidosa powder as co-metabolic substance

In coal gasification wastewater (CGW), nitrogen heterocyclic compounds (NHCs) are important refractory compounds. However, NHCs negatively impact human health and the environment due to its toxic, carcinogenic, and mutagenic properties. The main objective of this study was to determine the feasibility of Chlorella pyrenoidosa as a co-metabolite in enhancing anaerobic degradation of NHCs in CGW. So far, there have been few studies on enhanced anaerobic degradation with Chlorella pyrenoidosa as a co-metabolic substance. It was speculated that Chlorella pyrenoidosa had certain feasibility in the enhanced degradation of NHCs. Anaerobic Reactor 1 was operated as a control, while Reactor 2 was operated with the addition of Chlorella pyrenoidosa. When the concentration of Chlorella pyrenoidosa was 100 μg/L, Reactor 2 showed optimum degradation ratios on quinoline (100%) and indole (100%). Variations in the concentrations of Chlorella pyrenoidosa did not benefit the degradation efficiency of the reactor, whereby low dosages were not conducive for the microorganism’s growth and high dosages resulted in a competitive inhibition between the Chlorella powder and refractory compounds. In the effluent of Reactor 1, quinoline and indole concentrations were 12.79 ± 1.21 and 18.45 ± 1.11 mg/L, respectively. In Reactor 2, neither quinoline nor indole were detected. Acute bio-toxicity tests indicated a decrease in toxicity with the addition of Chlorella powder, hence reducing the inhibitions on seed germination and root elongation. The addition of Chlorella powder resulted in the increase of tryptophan protein and polysaccharide content in the extracellular polymeric substance of anaerobic sludge. In Reactor 2, bacterial community structures became more diverse and richer. Archaea communities became richer, but diversity declined. In the enhanced anaerobic degradation of NHCs, Chlorella pyrenoidosa powder was found to be an effective co-metabolite.

Activated carbon catalytic ozonation of reverse osmosis concentrate after coagulation pretreatment from coal gasification wastewater reclamation for zero liquid discharge

To fulfil the requirement of zero liquid discharge in the coal gasification wastewater treatment plant, evaporation and crystallization are usually adopted to treat reverse osmosis concentrate (ROC). However, their efficacies and the quality of their products are greatly affected by the organic matter concentration in coal gasification-ROC (CG-ROC). In the present study, ozonation with a commercial activated carbon (AC) as catalyst was conducted to further remove the organic matter in the concentrate originated from a three-stage RO after coagulation pretreatment. The kinetic model calculations were used for the first time to quantitatively evaluate the effect of matrix components on the performance of ozonation of CG-ROC at initial pH 9 and 11. The TOC removal difference among ozonation alone, ozonation alone followed by AC adsorption, and AC catalytic ozonation indicates that AC has a certain catalytic effect during ozonation of CG-ROC. The ΔO3/ΔTOC can be significantly reduced from 43.2 mg O3/mg TOC of ozonation alone to 16.2 mg O3/mg TOC of AC catalytic ozonation under the goal of achieving a similar TOC removal. The change of initial pH has little effect on the TOC removal during ozonation with AC, however, it has a remarkable effect on the TOC removal during ozonation alone. According to the results obtained in kinetic model calculations, high concentration of CO3•- would be generated from the reaction between HO• and CO32− with a high concentration in solution, leads to the delay on the TOC removal in the early reaction stage during ozonation alone at initial pH 11. The results of A254 and molecular weight (MW) distribution indicate that ozonation with AC is more efficient in removing the low MW intermediates absorption at 254 nm compared to that of ozonation alone. Ozonation with AC is more suitable for CG-ROC treatment since it is more energy saving, more efficient in organic matter removal, and more tolerated pH change and wastewater matrix compared to ozonation alone.

Comprehensive analysis of diverse biochemical treatment technologies of fixed-bed coal gasification wastewater from the perspective of different weight dimensions

Assessing the comprehensive performance of coal chemical wastewater process is an intricate and important task due to different biochemical treatment technologies. In this work, a 3E triangle model is developed to evaluate biochemical and advanced treatment technologies for zero liquid discharge of fix-bed coal gasification wastewater treatment process. In 3E triangle model, 19 key performance indicators are considered. In engineering performance aspect, up-flow anaerobic sludge blanket reactor case shows the best performance. In the life cycle environmental impact aspect, sequence batch reactor case shows the best performance through life cycle assessment, especially freshwater aquatic ecotoxicity potential and global warming potential. Generally, due to the higher fixed cost and power consumption of other technologies, the depreciation and variable cost of up-flow anaerobic sludge blanket reactor case are lower. Overall, the up-flow anaerobic sludge blanket reactor case shows excellent performance in 3E comprehensive performance. In addition, membrane bioreactor has better development prospects and its weight has a greatest impact which COD removal accounts for the majority.

Enhanced Degradation of Phenolic Compounds in Coal Gasification Wastewater by Methods of Microelectrolysis Fe-C and Anaerobic-Anoxic—Oxic Moving Bed Biofilm Reactor (A2O-MBBR)

The coal gasification wastewater figures prominently among types of industrial effluents due to its complex and phenolic composition, posing great difficulty for conventional water treatment processes. Since the coking wastewater is toxic and mutagenic to humans and animals, treatment of coal gasification wastewater is genuinely necessary. In this study, we established a lab-scale A2O (Anaerobic-Anoxic—Oxic) with moving bed biological reactor (MBBR) system and evaluated some water indicators of wastewater pretreated with internal electrolysis, of wastewater output of the established A2O-MBBR system, and of the wastewater treated by the combination thereof. The wastewater was taken from a coking plant at Thai Nguyen Iron and Steel Joint Stock Company in Vietnam. COD, BOD5, NH4+-N, phenol, and pH of the input coal gasification wastewater were 2359, 1105, 319, 172 mg/L, and 8 ± 0.1, respectively. The conditions of internal electrolysis were as follows: 720 min of reaction time, pH = 4, 25 g/L Fe-C dosage, and 100 mg/L PAM dosage. After internal electrolysis process, the removal of COD, BOD5, NH4+-N, and phenol were 53.7%, 56.7% 60.5%, and 73.3%, respectively. After 24 h of treatment, the treatment efficiencies of the combined treatment process are as follows: 100% phenol removal, 71.3% of TSS removal; 97.7% reduction of BOD5, and 97.1% reduction of COD; total N content reduced by 97.6%; total P content decreased by 81.6%; and NH4+-N content decreased by 97.5%. All above indicators after treatment have met QCVN 52: 2017/BTNMT (column A) Vietnamese standard for steel industry wastewater.

Pilot-scale catalytic ozonation pretreatment for improving the biodegradability of fixed-bed coal gasification wastewater

Achieving "zero liquid discharge" is a requirement for the development of the coal chemical industry; high pollutant concentration, strong biotoxicity, and poor biodegradability (BOD5/COD=0.1–0.2) make fixed-bed coal gasification wastewater difficult to treat. This study synthesized a Fe-Mn/lava catalyst (FMLC) and performed a pilot-scale test on catalytic ozonation for the pretreatment of fixed-bed coal gasification wastewater. The effects of ozone and catalyst dosages were investigated, and the changes in the organics, biotoxicity, and biodegradability of wastewater were analyzed using three-dimensional fluorescence spectroscopy, BOD5/COD, and specific oxygen uptake rate (SOUR). Energy consumption was also calculated. The removal efficiencies (at a flow rate of 1.0 m3/h, ozone dosage of 179 g/h, and catalyst dosage of 40 kg/m3) of COD and BOD5 were 61.77% and 16.98%, respectively, after 30 days of continuous operation. Toxic refractory macromolecular organic pollutants were transformed into small, biodegradable substances. BOD5/COD increased from 0.16 to 0.35, and SOUR decreased from 2.8460 to 2.3180 mgO2/(gMLSS∙h). The operating cost was 1.24 kWh/kgCOD. Catalytic ozonation as a pretreatment technology markedly improved biodegradability, reduced biotoxicity, and looks to be promising for treating fixed-bed coal gasification wastewater.