-->污染物治理与综合利用

Research on Improving the Fuel Properties of Black Liquor by Organic Pretreatment Combined with Catalytic Electrolysis

WANG Yang,LI Bolun,WANG Mengyan,LI Kaina,LUO Huixiang,YIN Yongjun — 2024/10/8 10:57:21

In this study， the weak black liquor （BL） obtained from sulfate pulping was taken as raw material， based on the organic pretreatment and catalytic electrolysis techniques， the organic small molecule components and lignin in the BL， and recover alkali were separated. Then， lignin was depolymerized into hydrocarbon fuels in order to improve the fuel properties of the BL. The results showed that about 98% alkali and 89.1% total lignin could be recovered by the process of organic pretreatment combined with catalytic electrolysis technology， and the liquefaction rate of lignin after electrochemical reduction treatment could reach up to 95.0%. The calorific value of black liquor upgraded fuel （BLUF-3） reached 35.1 MJ/kg， which was increased by 132% compared with that of the BL， and it had low apparent activation energy （23.4 kJ/mol） and high pre-exponential factor （2.68×10⁶ min^-1） which made it easier to ignite and burn. When the temperature was 123.52 ℃， BLUF had the maximum combustion rate of 10.8%/min， and its combustion characteristic index was higher than that of BL and other biomass oils， with high flammability.

Study on the Degradation of Lignin Model Compound Using a Dual Reaction Active Center Catalytic System

2024/10/8 10:57:23

A copper-iron bimetallic composite catalyst supported on activated carbon was prepared by using copper nitrate and iron nitrate as raw materials， which was utilized to activate persulfate to degrade lignin model compound （ferulic acid）. The optimum reactim conditions and effects of catalyst preparation conditions and reaction conditions on the catalytic activation efficiency of the material were also explored. It was found that 90% of ferulic acid could be degraded under the optimum condition （AC content was 6%， sodium persulfate concentration was 0.05 mol/L， dosage of catalyst was 0.03 g/L with molar ratio of Cu²⁺ to Fe³⁺ of 2∶1， pH value was 7）. Through the analysis of degradation intermediates， it was found that ferulic acid molecules could be degraded into carboxylic acids with small molecule weight through a series of oxidation reactions. Characterization by electron paramagnetic resonance technology indicated that the main reactive species in the catalytic system were sulfate radicals and hydroxyl radicals. The catalyst possessed good stability and recyclability.

Study on Removal Characteristics of Non-fiber Components of Pulp in MOW Reuse Treatment Process

2024/6/25 9:41:10

This study simulated the alkaline pulping process of mixed office waste paper （MOW） and explored the removal characteristics of non-fiber components of pulp in the various stages of reuse treatment as “pulping-flotation-washing-bleaching”. The results showed that in the pulping process， the removal rates of ash and starch were 71.5% and 59.5%， respectively. At this time， the removal rates of ink， dissolved and colloidal substances （DCS）， and Ca²⁺ were relatively low， at 29.4%， 18.4%， and 28.8%， respectively. In the flotation process， the removal rates of ink and Ca²⁺ were increased by 53.5 and 31.2 percentage points， while the removal efficiency of other non-fiber components was average. In the washing process， the removal characteristics of starch and DCS were obvious， with removal rates increased by 9.6 percentage points and 9.4 percentage points， respectively. In the bleaching process， the removal effect of non-fiber components of pulp was less affected by the bleaching conditions. In summary， the contents of ink， ash， starch， and Ca²⁺ in the pulp were significantly reduced after MOW reuse treatment process， but there were still varying degrees of retention in the pulp.

Preparation of Fe/Cu Dual Active Catalysts Based on Coal Gasification Slag and Their Application in Pulp and Paper Wastewater Applications in Deep Processing

HU Yin,MO Lihuan,LI Jun,PU Liwei,YANG Chenyi,CHEN Yongfa — 2024/6/25 9:41:11

Fe/Cu dual active heterogeneous Fenton catalyst was prepared using carbon silicon mesoporous material prepared by acid leaching of coal gasification slag as a carrier through carbon thermal reduction method. The preparation process of the catalyst was optimized and its catalytic effect on the removal of p-chlorophenol and treatment of pulp and paper wastewater by H₂O₂was investigated with p-chlorophenol as madel. The results showed that the catalyst prepared under the conditions of calcination temperature of 900 ℃， impregnation solution concentration of 0.2 mol/L， and Fe/Cu molar ratio of 2∶1 had the highest activity， with a removal rate of 96.8% for chlorophenol. Under the conditions of initial pH value=5， H₂O₂ dosage of 16 mmol/L， catalyst dosage of 1.25 g/L， and reaction time of 120 min， the COD_Cr removal rate of wastewater was 67.8%， the chromaticity removal rate was 97.4%， and the effluent COD_Cr was 63.13 mg/L.

Computational Simulation and Optimization of Pulping and Papermaking Wastewater Treatment System Based on UHOFe

LIANG Chen,HUANG Wenyu,DONG Yiwu,MENG Lijie,WEI Zishen,GAO Yufan,WANG Shuangfei — 2024/6/25 9:41:12

Under the condition of ensuring the hydraulic retention time of wastewater， in order to study the influence of the structure of upflow multiphase wastewater treatment oxidation tower （UHOFe） and the influent parameters and stirring speed on the uniformity of the internal flow regime in the reactor， the influence of loaded stirring blades on the internal flow field in the UHOFe reactor was investigated by the numerical simulation method of computational fluid dynamics （CFD）. Firstly， the parametric model of the reactor was established， and the in-plane velocity variation coefficient （MF） was introduced as the evaluation index of the inflow uniformity. Then， using the computer fluid dynamics software ANSYS 2022， combined with single factor and orthogonal experiments， the three-dimensional flow field numerical simulation for the flow state of internal fluid in the reactor was carried out. The simulation results showed that loaded stirring blades could strengthen the mixing of liquid in the reactor， and when the outlet height was 12 850 mm， the inlet velocity was 3 m/s， the stirring blade size was 1 300 mm， and the stirring speed was 140 r/min， the effect of water inflow uniformity in the reactor was the best， which was the most conducive to improving the mixing efficiency of Fenton system agents and ultimately improving the efficiency of sewage treatment.

Application of Ion Exchange Resin in Desalination of Papermaking Wastewater

GUO Longqing,RAN Hu,LI Xikang,WAN Jinquan,WANG Yan — 2024/5/30 14:33:44

In this study， 732 hydrogen type cation exchange resin （cation resin） and 201×7 hydroxide anion exchange resin （anion resin） were used for the desalination of papermaking wastewater. The adsorption properties of the resin for ions in papermaking wastewater during the static adsorption and dynamic adsorption were studied. The results showed that cation resin had obvious removal effect on Na⁺， Ca²⁺， Mg²⁺， and Fe³⁺ in the papermaking wastewater， and anion resin had obvious removal effect on Cl^- and SO₄^2-. The optimal static adsorption time was 15 min， and the desalting effect was best when combined with cation resin and anion resin mass ratio was 1.2∶1.4. In the process of dynamic adsorption， with the increase of flow velocity， the removal effect of resin on ions gradually weakened. The appropriate dynamic adsorption velocity of cation resin should be 4~12 BV/h， and the appropriate dynamic adsorption velocity of anion resin should be 4~10 BV/h. The optimal regeneration conditions of cation resin were the dynamic adsorption velocity of regenerated liquid 4 BV/h， the concentration of 4%， the volume of 3 BV， and the regeneration rate of 94%. The optimal regeneration conditions of cation resin were the dynamic adsorption velocity of regenerated liquid 4 BV/h， the concentration of 5%， the volume of 3 BV， and the regeneration rate of 84%. When the resin was fully regenerated several times after saturated adsorption， the regeneration rate of cation resin was kept above 90%， and that of anion resin was kept above 80%.

Exploration of the Influence of Pulping Waste Liquid on the Performance of Granular Fuel Based on the Establishment of Wheat Residues Granular Fuel Model

XUE Lanxin,LIN Zhaoyun,YANG Guihua,CHEN Jiachuan — 2024/4/22 0:00:00

Wheat residues and cellulose/hemicellulose as raw materials were separately mixed with pulping waste liquid to prepare biomass granular fuel and its model through direct compression molding technology. The physical performance and the combustion characteristics of granular fuel were systemically studied. The results showed that the pulping waste liquid had good adhesive property because of the presence of lignin， sugar， and other organic components， which could improve the physical properties of granular fuels. The maximum transverse compressive strength and calorific value of granular fuel prepared by pulping waste liquid with solid content of 4.29% were 128.28 MPa and 16 806.4 J/g， respectively， which were obviously higher than that of the granular fuel prepared by water， whereas the comprehensive combustion characteristics index was decreased to 1.69×10^-9%²/（min²·℃³）.

Analysis Model of Greenhouse Gas Emissions from Papermaking Wastewater Treatment Process Based on DNN-LSTM

LI Shizhong,MAN Yi,HE Zhenglei — 2024/4/22 0:00:00

This study employed deep learning algorithms to model and analyze greenhouse gas（GHG） emissions in the papermaking wastewater treatment process， providing insights for GHG reduction and control. Based on simulation experiments on the basehine simulation model 1（BSM1）， combined with the mechanisms of GHG generation in the papermaking wastewater treatment process， the deep neural network（DNN） and long short-term memory models （LSTM） were proposed for modeling and analyzing GHG emissions in the papermaking wastewater treatment process， to facilitate real-time monitoring and analysis of GHG. The results showed that deep learning could effectively describe GHG emission characteristics， with validation results showing R² > 0.99 and average relative errors below 1%. The DNN model-based sensitivity analysis results showed that sludge discharge， dissolved oxygen concentration， and internal circulation flow rate were key manipulated variables influencing GHG emissions， while the interactions between water quality variables and manipulated variables constituted potential influencing factors for the GHG emissions.

Research Progress and Thinking of Pulping and Papermaking Wastewater Treatment Technology

XU Congfeng,GUO Fangxing,HU Chun,LYU Lai — 2024/4/22 0:00:00

In this paper， the characteristics of pulping and papermaking wastewater and its environmental harm were briefly reviewed， the traditional technologies and latest research results for pulping and papermaking wastewater treatment were discussed， and the advantages and potentials of various technologies for the joint treatment of pulping and papermaking wastewater were summarized and analyzed. Finally， the new technology of efficient coupled treatment of pulping and papermaking wastewater and future thinking were proposed， which provided a reference for the practical application of efficient and low-consumption treatment technology for pulping and papermaking wastewater.

Practice of Odor Control in Pulp and Paper Wastewater Treatment Station

SONG Xu,LI Sulin,LI Zhixian,CHEN Zhiping,ZHENG Lishen — 2024/12/23 9:07:54

This study focused on the treatment of odorous waste gas emitted from wastewater during kraft pulping and regenerated papermaking. A combination process of “biotrickling filter+biofilter+alkaline scrubbing” was designed to treat the waste gas. After treatment， the emission rates of hydrogen sulfide， ammonia， methyl mercaptan， volatile organic compounds （VOCs）， and odor concentrations in the waste gas discharge outlet of the pulp line were reduced to 0.037 kg/h， 0.013 kg/h， 0.0230 kg/h， 2.374 kg/h， and 550， respectively. The emission rates of the same pollutants and odor concentrations in the waste gas discharge outlet of papermaking could be reduced to at least 0.020 kg/h， 0.021 kg/h， 0.000 6 kg/h， 0.013 kg/h， and 977， respectively， which met requirements of the “Emission Standards for Odor Pollutants” （GB 14554—1993） and the “Integrated Emission Standards of Air Pollutants” （GB 16297—1996）. The operating cost for per unit gas volume of this combined process was as low as 0.001 3 yuan/m³， with high treatment efficiency， providing an engineering demonstration for the design and implementation of waste gas treatment project in pulp and paper wastewater treatment station.

Heat Value Evaluation and Production Application of Black Liquor by Mixed Hardwood Kraft Pulping

GUO Caihong,YANG Zeguang,LI Shumu,LIU Haiyun — 2024/12/23 9:07:55

7 types of hardwood chips commonly used in sulfate pulp mills in southern China were cooked by laboratory kraft pulping （KP） process. The various hardwood chips were cooked to Kappa value about 18 by KP. Analysis the components and recoverable heat energy from black liquor of per unit of wood（Q） of black liquor. Analysis the linear regression relationship between the weighted experimental value（Q_S）and production measurement（Q_N） of recoverable heat value of black liquor under mixed cooking conditions， and a relevant prediction model was established. The results showed that the Q values of Hainan eucalyptus and Australian eucalyptus globulus were the highest， reaching 490 kcal/kg and 468 kcal/kg， respectively， Q value of Vietnamese acacia was the lowest， only 157 kcal/kg， other Q value of tree species ranged from 244~304 kcal/kg. The functional relationship between Q_N（y） and Q_S （x） was obtained as y = 0.672x-121.41. Using the model to predict the black liquor properties of the new raw material， the error of the prediction result was less than 5 kcal/kg， indicating that the model could be used to predict the heat value of the black liquor obtained from the KP process of mixed hardwood chips in industrial production.

Effect of Calcification on the Characteristics of Granular Sludge in Anaerobic Reactor

PENG Ling,ZHANG Jian,WANG Shuangfei — 2024/11/22 15:48:46

This study investigated a calcified anaerobic reactor at a waste paper pulping company， where granular samples were collected over a year. Systematic analysis of the physicochemical and biological properties of the granules revealed that calcium carbonate accumulation during calcification led to increased Ca²⁺ content， higher ash content， accelerated settling velocity and larger diameter. Prolonged exposure to high-calcium wastewater significantly enhanced the relative abundance of hydrogen-producing acetogens in the bacterial community， while the abundance of hydrolytic bacteria and acidogens declined. In the archaeal community， the original dominant methanogens Methanobacterium decreased， while archaea adapted to the high-calcium environment showed significant growth， such as Bathyarchaeia， Methanolinea， and Candidatus_Methanofastidiosum. These changes in physicochemical properties and microbial community succession provided critical insights into the response mechanisms of granular sludge under calcification stress.

Research Progress on Pyrolysis Treatment of Papermaking Sludge

HUO Benlong,MA Wen — 2024/11/22 15:48:47

This paper summarized the current status of sewage sludge treatment， especially the advantages of pyrolysis in the sewage sludge treatment process， from the perspective of the sources and treatment methods of sewage sludge， and explored the characteristics of pyrolysis products （bio-oil， biochar， and pyrolysis gas） from sewage sludge and their applications in various fields. The future development trends， opportunities， and challenges of sludge pyrolysis technology were prospected.

Study on the Cause Analysis of Performance Decline and Enhancement by Coagulation Pretreatment in Camphorwood Chemi-mechanical Pulping Wastewater Treatment System

ZHONG Tianqi,ZUO Jian’e — 2026/4/21 10:08:05

The response characteristics of key indicators such as CODin the anaerobic， aerobic and advanced treatment units of a pulp and paper mill in Hu’nan province from 2021 to 2024 were tracked in this study， to analyze the inhibitory effect of camphorwood process wastewater on the anaerobic treatment unit in relation to the changes in camphorwood consumption during APMP pulping. The results showed that as the proportion of camphorwood increased from 4.24% to 12.81%， the COD_Cr volumetric loading rate of the anaerobic system exceeded the design value by 29%， and the influent COD_Cr concentration increased by 16.5%. Luminescent bacteria toxicity tests confirmed that the 100% camphorwood chemimechanical pulping wastewater exhibited the highest toxicity， and the toxicity increased with the increasing COD concentration. Under identical COD_Cr loading conditions， the anaerobic COD_Cr removal efficiency decreased in a dose-dependent manner when the camphorwood pulping wastewater proportion increased from 5% to 15%. On this basis， the efficacy of introducing coagulation pretreatment upstream of the anaerobic unit for the influent quality improvement was evaluated in this study. Under the optimized conditions (5 g/L PAC with appropriate PAM)， the coagulation pretreatment reduced the influent COD_Cr and SS by 25.9% and 28.7%， respectively， and increased the subsequent anaerobic COD_Cr removal efficiency by 14.5%.

Analysis and Countermeasures of Green Mud-like Precipitation in Chemi-mechanical Pulping Pre-impregnation Stage

CAO Yanjun,WANG Dong,JIANG Haipeng,DU Chongyang,ZHANG Guoxiang,LIANG Jian — 2026/4/21 10:08:07

Aiming at the problem of green mud-like sediments (green mud) occurring in the waste liquid pipes of the chemi-mechanical pulping (CMP) pre-impregnation stage, the production line of an enterprise in Guangxi was taken as the research object in this study. The chemical composition, microstructure and formation mechanism of green mud were systematically investigated by means of multiple analytical techniques. The results showed that the green mud was mainly composed of alkaline degradation products of lignin, inorganic salt crystals, and transition metal-organic complexes. The green mud characteristic was mainly derived from the metal-organic complexes formed by iron ions and polyhydric phenol ligands in lignin degradation products. The metal ions (such as calcium, magnesium, and iron) enriched in the recycled alkaline solution were identified as important material sources for the formation of green mud. Based on the above mechanism, a multi-level prevention and control strategy was proposed, which included source ion control, process chelating agent regulation and regular system cleaning. This study provided a theoretical basis and practical guidance for the effective prevention and control of green mud deposition in the CMP production system.

Interference Mechanisms and Elimination Methods for COD Determination Distortion in the PS-AOPs Process for Papermaking Wastewater Treatment

GUO Fusen,GE Qiang,ZHOU Xianbo,WANG Yan,ZHU Congyun,LIU Kuanyong,WAN Jinquan — 2026/4/21 10:08:08

To address the issue of COD measurement distortion in papermaking wastewater treatment using persulfate-based advanced oxidation processes (PS-AOPs)， this study identified S₂O82-， Fe²⁺， and Cl^- as the primary interference sources through monitoring data and elemental analysis (ICP-MS/IC). The interference mechanisms manifested as positive interference caused by oxidant consumption， negative interference due to titrant depletion， and their nonlinear superposition in complex matrices. Based on these findings， an integrated elimination protocol was developed and validated： S₂O82- was reduced using Na₂SO₃ (mass ratio≥1∶1 at 90 ℃ for 60 min， achieving >94% removal)； HgSO₄ masking was optimized according to Cl^- concentration (mass ratio 15∶1， with <5% error)； and Fe²⁺ was corrected via stoichiometric calibration. Spike and recovery experiments demonstrated recoveries of 97%~102%， confirming that the protocol effectively overcame complex matrix interferences and significantly improved COD measurement accuracy.

Design and Application of Pretreatment Process for High-concentration Wastewater from 6 000 t/a Pulping Residue Processing System

DU Jianyang,LI Nan,XU Piyuan,SUN Tingcong,FAN Shujie,WANG Yuejiang,SU Zhenhua — 2026/5/12 14:53:36

To treat the 3 600 m³/d of highly concentrated organic wastewater (chemical oxygen demand (COD_Cr)≈45 000 mg/L， suspended solids (SS) content≈21 000 mg/L) generated during the resource recovery process of 6 000 t/a pulping residue， this study designed and constructed a pretreatment process based on coagulation and clarification technology， which prior to discharging into the existing wastewater treatment system. Operational results indicated that， using a flocculant blend comprising polyaluminum chloride (PFC， Fe³⁺≥11%)， polyacrylamide (PAM， mass fraction 0.1%)， and clay emulsion (mass fraction from 1.5% to 1.7%)， the pretreatment technology achieved a COD_Cr removal rate of ≥75% for the high-concentration wastewater， with a SS content removal rate of ≥95%. The effluent COD_Cr was ≤918 mg/L and SS content was ≤132 mg/L， meeting the influent requirements of the existing wastewater treatment system. Additionally， the biodegradability (BOD₅/COD_Cr) of the effluent in the system improved by approximately 5%. It effectively resolved clogging issues in the subsequent wastewater treatment system， reduced chemical consumption in the shallow-bed flotation unit by 50%， and improved sludge dewatering efficiency.

Preparation of Calcium Carbonate Composite Materials and Their Adsorption of Fe³⁺

JIAO Xinye,JIANG Xue,TIAN Xiuzhi,DU Yichun,XIAO Jiale,XIANG Zhong,LI Yuhang — 2026/4/21 10:08:10

This study aimed to investigate the influence mechanisms of dopamine (DA) and sodium alginate (SA) as regulating agents on the structure of calcium carbonate composites and their adsorption performance for Fe³⁺. By adjusting the concentrations of DA and SA, the regulatory effects on the crystal phase, microstructure, and particle size distribution of calcium carbonate were systematically studied, and the adsorption performance and cycling stability of the two composites for Fe³⁺ were compared. The results showed that the adsorption behavior of DA-CaCO₃ conformed to the Freundlich isothermal adsorption model, indicating its heterogeneous surface and adsorption dominated by multilayer physisorption and weak chemical interactions with Fe³⁺. In contrast, SA-CaCO₃ better followed the Langmuir isothermal adsorption model, suggesting relatively uniform surface sites and a monolayer chemisorption process dominated by chelation, with a theoretical maximum adsorption capacity of 515.36 mg/g. Cycling experiments further showed that SA-CaCO₃ maintained a removal rate above 80% towards Fe³⁺ after 5 times of adsorption-desorption cycles， demonstrating a good regeneration stability.