TRENDS IN SLUDGE RESEARCH: INNOVATIONS, CHALLENGES AND FUTURE PERSPECTIVES

Authors

  • Nurul Nabilah Shuaib Faculty of Chemical Engineering & Technology, Universiti Malaysia Perlis, 02600 Arau, Perlis, Malaysia
  • Fathin Ayuni Azizan Faculty of Mechanical Engineering & Technology, Universiti Malaysia Perlis, 02600 Arau, Perlis, Malaysia
  • Noorulnajwa Diana Yaakob Faculty of Chemical Engineering & Technology, Universiti Malaysia Perlis, 02600 Arau, Perlis, Malaysia
  • Munira Mohamed Nazari Faculty of Mechanical Engineering &Technology, Universiti Malaysia Perlis, 02600 Arau, Perlis, Malaysia
  • Siti Fatimah Zaharah M Fuzi Faculty of Sciences & Technology, Universiti Tun Hussein Onn Malaysia, Edu Hub Pagoh, 04600, Pagoh, Johor, Malaysia
  • Nasratun Masngut Faculty of Chemical and Process Engineering Technology, Universiti Malaysia Pahang Al-Sultan Abdullah, Lebuhraya Persiaran Tun Khalil Yaakob, 26300 Kuantan, Pahang, Malaysia
  • Yogan Jaya Kumar Fakulti Teknologi Maklumat dan Komunikasi, Universiti Teknikal Malaysia Melaka, Melaka, Malaysia

DOI:

https://doi.org/10.11113/jurnalteknologi.v88.23437

Keywords:

Sludge management, Wastewater treatment, Resource recovery, Environmental impacts, Sustainable disposal

Abstract

The management and valorization of sludge from wastewater treatment plants represent critical challenges due to environmental concerns, regulatory pressures, and sustainable development policies. In wastewater treatment, sludge is generated as primary solids during sedimentation and as secondary biomass from biological processes, and is typically thickened, stabilized, and dewatered before treatment or reuse. This review aims to synthesize recent developments in sludge treatment technologies, focusing on resource recovery-based technological advancements and progress toward minimizing the environmental impacts of sludge disposal as well exploring for sustainable options and solutions. Specifically, the review synthesizes developments across biological (anaerobic digestion), thermal (pyrolysis, hydrothermal processing), and chemical (precipitation, membrane) methods that underpin resource recovery and environmental protection and summarize how sludge is subsequently managed through treatment and valorization pathways. This paper provides an overview of recent advancements in this field, highlights common problems and presents the committee with a plan on how to alter studies that could lead to innovative research for sludge management by reviewing relevant past research.

References

Hassan, F., et al. 2023. Microplastic Contamination in Sewage Sludge: Abundance, Characteristics, and Impacts on the Environment and Human Health. Environmental Technology & Innovation. 31: 103176. https://doi.org/10.1016/j.eti.2023.103176.

Omotayo, O. P., and O. O. Babalola. 2021. Resident Rhizosphere Microbiome’s Ecological Dynamics and Conservation: Towards Achieving the Envisioned Sustainable Development Goals, a Review. International Soil and Water Conservation Research. 9(1): 127–142. https://doi.org/10.1016/j.iswcr.2020.08.002.

Zieliński, M., J. Kazimierowicz, and M. Dębowski. 2023. Advantages and Limitations of Anaerobic Wastewater Treatment—Technological Basics, Development Directions, and Technological Innovations. Energies. 16(1). https://doi.org/10.3390/en16010083.

Rulkens, W. 2008. Sewage Sludge as a Biomass Resource for the Production of Energy: Overview and Assessment of the Various Options. Energy & Fuels. 22(1): 9–15. https://doi.org/10.1021/ef700267m.

Puyol, D., D. J. Batstone, T. Hülsen, S. Astals, M. Peces, and J. O. Krömer. 2017. Resource Recovery from Wastewater by Biological Technologies: Opportunities, Challenges, and Prospects. Frontiers in Microbiology. 7: 2106. https://doi.org/10.3389/fmicb.2016.02106.

Bazarnova, J. G., N. A. Politayeva, and S. G. Bozhuk. 2017. Innovative Technologies Secondary Use of Processed Active Source. In Proceedings of the 2017 International Conference ‘Quality Management, Transport and Information Security, Information Technologies’ (IT&QM&IS). 471–476. https://doi.org/10.1109/ITMQIS.2017.8085865.

Peccia, J., and P. Westerhoff. 2015. We Should Expect More out of Our Sewage Sludge. Environmental Science & Technology. 49(14): 8271–8276. https://doi.org/10.1021/acs.est.5b01931.

Zarei, M. 2020. Wastewater Resources Management for Energy Recovery from Circular Economy Perspective. Water-Energy Nexus. 3: 170–185. https://doi.org/10.1016/j.wen.2020.11.001.

Ngo, H. H., et al. 2020. Nutrient Recovery in Anaerobic Membrane Bioreactors. In Current Developments in Biotechnology and Bioengineering: Advanced Membrane Separation Processes for Sustainable Water and Wastewater Management – Anaerobic Membrane Bioreactor Processes and Technologies. 283–307. Elsevier, https://doi.org/10.1016/B978-0-12-819852-0.00012-9.

Edifor, S. Y., P. Van Eyk, P. Biller, and D. M. Lewis. 2020. The Influence of Feedstock Characteristics on Processability of Biosolid Slurries for Conversion to Renewable Crude Oil via Hydrothermal Liquefaction. Chemical Engineering Research and Design. 162: 284–294. https://doi.org/10.1016/j.cherd.2020.08.016.

Awasthi, M. K., et al. 2017. Evaluation of Biochar Amended Biosolids Co-Composting to Improve the Nutrient Transformation and Its Correlation as a Function for the Production of Nutrient-Rich Compost. Bioresource Technology. 237: 156–166. https://doi.org/10.1016/j.biortech.2017.01.044.

Skaggs, R. L., A. M. Coleman, T. E. Seiple, and A. R. Milbrandt. 2018. Waste-to-Energy Biofuel Production Potential for Selected Feedstocks in the Conterminous United States. Renewable and Sustainable Energy Reviews. 82: 2640–2651. https://doi.org/10.1016/j.rser.2017.09.107.

Posmanik, R., R. A. Labatut, A. H. Kim, J. G. Usack, J. W. Tester, and L. T. Angenent. 2017. Coupling Hydrothermal Liquefaction and Anaerobic Digestion for Energy Valorization from Model Biomass Feedstocks. Bioresource Technology. 233: 134–143. https://doi.org/10.1016/j.biortech.2017.02.095.

Kabeyi, M. J. B., and O. A. Olanrewaju. 2022. Biogas Production and Applications in the Sustainable Energy Transition. Journal of Energy. 2022: 8750221. https://doi.org/10.1155/2022/8750221.

Meegoda, J. N., B. Li, K. Patel, and L. B. Wang. 2018. A Review of the Processes, Parameters, and Optimization of Anaerobic Digestion. International Journal of Environmental Research and Public Health. 15(10): 2224. https://doi.org/10.3390/ijerph15102224.

Dai, N. H., K. T. T. Huynh, T. A. D. Nguyen, V. V. T. Do, and M. Van Tran. 2021. Hydrothermal and Steam Explosion Pretreatment of Bambusa stenostachya Bamboo. Waste and Biomass Valorization. 12(7): 4103–4112. https://doi.org/10.1007/s12649-020-01299-5.

Liu, X., Q. Wang, Y. Tang, and S. G. Pavlostathis. 2021. Hydrothermal Pretreatment of Sewage Sludge for Enhanced Anaerobic Digestion: Resource Transformation and Energy Balance. Chemical Engineering Journal. 410: 127430. https://doi.org/10.1016/j.cej.2020.127430.

Balasundaram, G., P. Gahlot, V. K. Tyagi, and A. A. Kazmi. 2023. Advanced Steam Explosion as Thermal Hydrolysis Process for High Solids Anaerobic Digestion and Enhanced Methane Yield: Proof of Concept. Sustainable Chemistry and Pharmacy. 36: 101274. https://doi.org/10.1016/j.scp.2023.101274.

Wang, S., C. Xu, L. Song, and J. Zhang. 2022. Anaerobic Digestion of Food Waste and Its Microbial Consortia: A Historical Review and Future Perspectives. International Journal of Environmental Research and Public Health. 19(15): 9519. https://doi.org/10.3390/ijerph19159519.

Lim, J. W., T. Park, Y. W. Tong, and Z. Yu. 2020. The Microbiome Driving Anaerobic Digestion and Microbial Analysis. In Advances in Biochemical Engineering/Biotechnology. Amsterdam: Elsevier. https://doi.org/10.1016/bs.aibe.2020.04.001.

Zhang, Q., et al. 2019. High Variations of Methanogenic Microorganisms Drive Full-Scale Anaerobic Digestion Process. Environment International. 126: 543–551. https://doi.org/10.1016/j.envint.2019.03.005.

Treu, L., P. G. Kougias, S. Campanaro, I. Bassani, and I. Angelidaki. 2016. Deeper Insight into the Structure of the Anaerobic Digestion Microbial Community; The Biogas Microbiome Database Is Expanded with 157 New Genomes. Bioresource Technology. 216: 260–266. https://doi.org/10.1016/j.biortech.2016.05.081.

Hassa, J., et al. 2018. Metagenome, Metatranscriptome, and Metaproteome Approaches Unraveled Compositions and Functional Relationships of Microbial Communities Residing in Biogas Plants. Applied Microbiology and Biotechnology. 102(12): 5045–5063. https://doi.org/10.1007/s00253-018-8976-7.

Krohn, C., et al. 2022. The Role of Microbial Ecology in Improving the Performance of Anaerobic Digestion of Sewage Sludge. Frontiers in Microbiology. 13: 1079136. https://doi.org/10.3389/fmicb.2022.1079136.

Hagen, L. H., et al. 2017. Quantitative Metaproteomics Highlight the Metabolic Contributions of Uncultured Phylotypes in a Thermophilic Anaerobic Digester. Applied and Environmental Microbiology. 83(2): e01955–16. https://doi.org/10.1128/AEM.01955-16.

Ho, D. P., P. D. Jensen, and D. J. Batstone. 2013. Methanosarcinaceae and Acetate-Oxidizing Pathways Dominate in High-Rate Thermophilic Anaerobic Digestion of Waste-Activated Sludge. Applied and Environmental Microbiology. 79(20): 6491–6500. https://doi.org/10.1128/AEM.01730-13.

Venkiteshwaran, K., K. Milferstedt, J. Hamelin, M. Fujimoto, M. Johnson, and D. H. Zitomer. 2017. Correlating Methane Production to Microbiota in Anaerobic Digesters Fed Synthetic Wastewater. Water Research. 110: 161–169. https://doi.org/10.1016/j.watres.2016.12.010.

Liu, F., J. Li, and X. L. Zhang. 2019. “Bioplastic Production from Wastewater Sludge and Application.” IOP Conference Series: Earth and Environmental Science 344 (1): 012071. https://doi.org/10.1088/1755-1315/344/1/012071.

Ezugbe, E. O., and S. Rathilal. 2020. Membrane Technologies in Wastewater Treatment: A Review. Membranes. 10(5): 89. https://doi.org/10.3390/membranes10050089.

Wang, Y. N., K. Goh, X. Li, L. Setiawan, and R. Wang. 2018. Membranes and Processes for Forward Osmosis-Based Desalination: Recent Advances and Future Prospects. Desalination. 434: 81–99. https://doi.org/10.1016/j.desal.2017.10.028.

Pervez, M. N., et al. 2020. A Critical Review on Nanomaterials Membrane Bioreactor (NMS-MBR) for Wastewater Treatment. npj Clean Water. 3(1). https://doi.org/10.1038/s41545-020-00090-2.

Do, K.-U., and X.-Q. Chu. 2022. Performances of Membrane Bioreactor Technology for Treating Domestic Wastewater Operated at Different Sludge Retention Time. In Development in Wastewater Treatment Research and Processes. 107–122. Amsterdam: Elsevier. https://doi.org/10.1016/B978-0-323-85583-9.00010-7.

Rahman, T. U., et al. 2023. The Advancement in Membrane Bioreactor (MBR) Technology toward Sustainable Industrial Wastewater Management. Membranes. 13(2): 181. https://doi.org/10.3390/membranes13020181.

Lei, Z., S. Yang, Y. You Li, W. Wen, X. C. Wang, and R. Chen. 2018. Application of Anaerobic Membrane Bioreactors to Municipal Wastewater Treatment at Ambient Temperature: A Review of Achievements, Challenges, and Perspectives. Bioresource Technology. 267: 756–768. https://doi.org/10.1016/j.biortech.2018.07.050.

Wang, H., et al. 2024. Membrane-Based Technology in Water and Resources Recovery from the Perspective of Water Social Circulation: A Review. Science of the Total Environment. 908: 168277. https://doi.org/10.1016/j.scitotenv.2023.168277.

Mahmoodi, N. M., and M. H. Saffar-Dastgerdi. 2019. Zeolite Nanoparticle as a Superior Adsorbent with High Capacity: Synthesis, Surface Modification and Pollutant Adsorption Ability from Wastewater. Microchemical Journal. 145: 74–83. https://doi.org/10.1016/j.microc.2018.10.018.

Bjorge, D., et al. 2009. Performance Assessment of Electrospun Nanofibers for Filter Applications. Desalination. 249(3): 942–948. https://doi.org/10.1016/j.desal.2009.06.064.

Khan, F., A. B. Siddique, S. Shabala, M. Zhou, and C. Zhao. 2023. Phosphorus Plays Key Roles in Regulating Plants’ Physiological Responses to Abiotic Stresses. Plants. 12(15): 2861. https://doi.org/10.3390/plants12152861.

Vu, M. T., et al. 2023. Recent Technological Developments and Challenges for Phosphorus Removal and Recovery toward a Circular Economy. Environmental Technology & Innovation. 30: 103114. https://doi.org/10.1016/j.eti.2023.103114.

Salkunić, A., J. Vuković, and S. Smiljanić. 2022. Review of Technologies for the Recovery of Phosphorus from Waste Streams. Chemical and Biochemical Engineering Quarterly. 36(2): 91–116. https://doi.org/10.15255/CABEQ.2022.2066.

Di Capua, F., et al. 2022. Phosphorous Removal and Recovery from Urban Wastewater: Current Practices and New Directions. Science of the Total Environment. 823: 153750. https://doi.org/10.1016/j.scitotenv.2022.153750.

Christensen, M. L., C. Cvitanich, C. A. Quist-Jensen, M. Thau, and B. Malmgren-Hansen. 2022. Precipitation and Recovery of Phosphorus from the Wastewater Hydrolysis Tank. Science of the Total Environment. 813: 151875. https://doi.org/10.1016/j.scitotenv.2021.151875.

Zarrabi, M., M. M. Soori, M. N. Sepehr, A. Amrane, S. Borji, and H. R. Ghaffari. 2014. Removal of Phosphorus by Ion-Exchange Resins: Equilibrium, Kinetic and Thermodynamic Studies. Environmental Engineering and Management Journal. 13(4): 891–903. https://doi.org/10.30638/eemj.2014.093.

Ding, Y., X. Dai, B. Wu, Z. Liu, and L. Dai. 2022. Targeted Clean Extraction of Phosphorus from Waste Activated Sludge: From a New Perspective of Phosphorus Occurrence States to an Innovative Approach through Acidic Cation Exchange Resin. Water Research. 215: 118190. https://doi.org/10.1016/j.watres.2022.118190.

Daneshgar, S., A. Callegari, A. G. Capodaglio, and D. Vaccari. 2018. The Potential Phosphorus Crisis: Resource Conservation and Possible Escape Technologies: A Review. Resources. 7(2): 37. https://doi.org/10.3390/resources7020037.

Ghodke, P. K., A. K. Sharma, J. K. Pandey, W. H. Chen, A. Patel, and V. Ashokkumar. 2021. Pyrolysis of Sewage Sludge for Sustainable Biofuels and Value-Added Biochar Production. Journal of Environmental Management. 298: 113450. https://doi.org/10.1016/j.jenvman.2021.113450.

Alvarez, J., M. Amutio, G. Lopez, I. Barbarias, J. Bilbao, and M. Olazar. 2015. Sewage Sludge Valorization by Flash Pyrolysis in a Conical Spouted Bed Reactor. Chemical Engineering Journal. 273: 173–183. https://doi.org/10.1016/j.cej.2015.03.047.

de Souza Souza, C., et al. 2021. Induced Changes of Pyrolysis Temperature on the Physicochemical Traits of Sewage Sludge and on the Potential Ecological Risks. Scientific Reports. 11(1): 1–14. https://doi.org/10.1038/s41598-020-79658-4.

Li, S., and D. Tasnady. 2023. Biochar for Soil Carbon Sequestration: Current Knowledge, Mechanisms, and Future Perspectives. C-Journal of Carbon Research. 9(3): 67. https://doi.org/10.3390/c9030067.

Zhao, L., et al. 2023. “Sewage Sludge Derived Biochar for Environmental Improvement: Advances, Challenges, and Solutions. Water Research X. 18: 100167. https://doi.org/10.1016/j.wroa.2023.100167.

Han, L., J. Li, C. Qu, Z. Shao, T. Yu, and B. Yang. 2022. Recent Progress in Sludge Co-Pyrolysis Technology. Sustainability. 14(13): 7574. https://doi.org/10.3390/su14137574.

Morgan-Sagastume, F., et al. 2014. Polyhydroxyalkanoate (PHA) Production from Sludge and Municipal Wastewater Treatment. Water Science and Technology. 69(1): 177–184. https://doi.org/10.2166/wst.2013.643.

Zhang, Z., et al. 2024. Towards Scaling-Up Implementation of Polyhydroxyalkanoate (PHA) Production from Activated Sludge: Progress and Challenges. Journal of Cleaner Production. 447: 141542. https://doi.org/10.1016/j.jclepro.2024.141542.

Chahal, C., B. van den Akker, F. Young, C. Franco, J. Blackbeard, and P. Monis. 2016. Pathogen and Particle Associations in Wastewater: Significance and Implications for Treatment and Disinfection Processes. In Advances in Applied Microbiology. 97: 63–119. Amsterdam: Elsevier. https://doi.org/10.1016/bs.aambs.2016.08.001.

Alipour, M., H. Asadi, C. Chen, and M. R. Rashti. 2021. Bioavailability and Eco-Toxicity of Heavy Metals in Chars Produced from Municipal Sewage Sludge Decreased during Pyrolysis and Hydrothermal Carbonization. Ecological Engineering. 162: 106173. https://doi.org/10.1016/j.ecoleng.2021.106173.

Lyu, H., Y. Gong, J. Tang, Y. Huang, and Q. Wang. 2016. Immobilization of Heavy Metals in Electroplating Sludge by Biochar and Iron Sulfide. Environmental Science and Pollution Research. 23(14): 14472–14488. https://doi.org/10.1007/s11356-016-6621-5.

Zhang, X., X. Q. Wang, and D. F. Wang. 2017. Immobilization of Heavy Metals in Sewage Sludge during Land Application Process in China: A Review. Sustainability. 9(11): 2020. https://doi.org/10.3390/su9112020.

Li, C., et al. 2022. Enhancement of Heavy Metal Immobilization in Sewage Sludge Biochar by Combining Alkaline Hydrothermal Treatment and Pyrolysis. Journal of Cleaner Production. 369: 133325. https://doi.org/10.1016/j.jclepro.2022.133325.

Dhokpande, S. R., S. M. Deshmukh, A. Khandekar, and A. Sankhe. 2024. A Review Outlook on Methods for Removal of Heavy Metal Ions from Wastewater. Separation and Purification Technology. 350: 127868. https://doi.org/10.1016/j.seppur.2024.127868.

Ahmed, W., et al. 2021. Utilization of Citrullus lanatus L. Seeds to Synthesize a Novel MnFe₂O₄-Biochar Adsorbent for the Removal of U(VI) from Wastewater: Insights and Comparison between Modified and Raw Biochar. Science of the Total Environment. 771: 144955. https://doi.org/10.1016/j.scitotenv.2021.144955.

Tyagi, S., and A. Annachhatre. 2023. A Review on Recent Trends in Solidification and Stabilization Techniques for Heavy Metal Immobilization. Journal of Material Cycles and Waste Management. 25: 733–757. https://doi.org/10.1007/s10163-022-01583-7.

Yemmireddy, V., A. Adhikari, and J. Moreira. 2022. Effect of Ultraviolet Light Treatment on Microbiological Safety and Quality of Fresh Produce: An Overview. Frontiers in Nutrition. 9: 871243. https://doi.org/10.3389/fnut.2022.871243.

Sun, X., et al. 2022. Partial Ozonation of Returned Sludge via High-Concentration Ozone to Reduce Excess Sludge Production: A Pilot Study. Science of the Total Environment. 807: 150773. https://doi.org/10.1016/j.scitotenv.2021.150773.

Andersen, K. B., A. Feilberg, and J. A. Beukes. 2012. Use of Non-Thermal Plasma and UV-Light for Removal of Odour from Sludge Treatment. Water Science and Technology. 66(8): 1656–1662. https://doi.org/10.2166/wst.2012.367.

Tian, X., A. P. Trzcinski, L. L. Lin, and W. J. Ng. 2015. Impact of Ozone Assisted Ultrasonication Pre-Treatment on Anaerobic Digestibility of Sewage Sludge. Journal of Environmental Sciences. 33: 29–38. https://doi.org/10.1016/j.jes.2015.01.003.

Cosgun, S., and N. Semerci. 2019. Combined and Individual Applications of Ozonation and Microwave Treatment for Waste Activated Sludge Solubilization and Nutrient Release. Journal of Environmental Management. 241: 76–83. https://doi.org/10.1016/j.jenvman.2019.04.001.

Nageeb, M. 2013. Adsorption Technique for the Removal of Organic Pollutants from Water and Wastewater. In Organic Pollutants—Monitoring, Risk and Treatment. Rijeka: InTech. https://doi.org/10.5772/54048.

Allahkarami, E., and A. D. Monfared. 2024. Activated Carbon Adsorbents for the Removal of Emerging Pollutants and Its Adsorption Mechanisms. In Sustainable Remediation Technologies for Emerging Pollutants in Aqueous Environment. edited by M. H. Dehghani, R. R. Karri, and I. Tyagi. 79–109. Amsterdam: Elsevier. https://doi.org/10.1016/B978-0-443-18618-9.00011-5.

Tyagi, U., and N. Anand. 2024. Sustainable and Low-Cost Biomass Derived Adsorbents for the Removal of Toxic Contaminants from Wastewater: Approaches and Future Perspective. Waste Management Bulletin. 2(2): 308–325. https://doi.org/10.1016/j.wmb.2024.05.010.

Liu, Y., et al. 2022. Utilization of Waste Sludge: Activation/Modification Methods and Adsorption Applications of Sludge-Based Activated Carbon. Journal of Water Process Engineering. 49: 103111. https://doi.org/10.1016/j.jwpe.2022.103111.

Priyadarshini, M., I. Das, M. M. Ghangrekar, and L. Blaney. 2022. Advanced Oxidation Processes: Performance, Advantages, and Scale-Up of Emerging Technologies. Journal of Environmental Management. 316: 115295. https://doi.org/10.1016/j.jenvman.2022.115295.

Al-Bsoul, A., et al. 2020. Optimal Conditions for Olive Mill Wastewater Treatment Using Ultrasound and Advanced Oxidation Processes. Science of the Total Environment. 700: 134576. https://doi.org/10.1016/j.scitotenv.2019.134576.

Lin, W., et al. 2022. Advanced Oxidation Processes (AOPs)-Based Sludge Conditioning for Enhanced Sludge Dewatering and Micropollutants Removal: A Critical Review. Journal of Water Process Engineering. 45: 102468. https://doi.org/10.1016/j.jwpe.2021.102468.

Awe, Y. T., and L. Ogunkanmi. 2022. Microbial Enzymes of Wastewater and Sludge. In Ecological Interplays Between Microbial Enzymology. 37–59. Singapore: Springer. https://doi.org/10.1007/978-981-19-0155-3_3.

Quintero-García, O. J., H. Pérez-Soler, and M. A. Amezcua-Allieri. 2023. Enzymatic Treatments for Biosolids: An Outlook and Recent Trends. International Journal of Environmental Research and Public Health. 20(6): 4804. https://doi.org/10.3390/ijerph20064804.

Cadoret, A., A. Conrad, and J. Block. 2002. Availability of Low and High Molecular Weight Substrates to Extracellular Enzymes in Whole and Dispersed Activated Sludges. Enzyme and Microbial Technology. 31: 179–186. https://doi.org/10.1016/S0141-0229(02)00097-2.

Burgess, J. E., and B. I. Pletschke. 2008. Hydrolytic Enzymes in Sewage Sludge Treatment: A Mini-Review. Water SA. 34(3): 343–349. https://doi.org/10.4314/wsa.v34i3.180627.

Barjenbruch, M., and O. Kopplow. 2003. Enzymatic, Mechanical and Thermal Pre-Treatment of Surplus Sludge. Advances in Environmental Research. 7(3): 715–720. https://doi.org/10.1016/S1093-0191(02)00032-1.

Braine, M. F., M. Kearnes, and S. J. Khan. 2024. Quality and Risk Management Frameworks for Biosolids: An Assessment of Current International Practice. Science of the Total Environment. 915: 169953. https://doi.org/10.1016/j.scitotenv.2024.169953.

Patel, K., and S. K. Singh. 2022. A Life Cycle Approach to Environmental Assessment of Wastewater and Sludge Treatment Processes. Water and Environment Journal. 36(3): 412–424. https://doi.org/10.1111/wej.12774.

Cairone, S., et al. 2024. Revolutionizing Wastewater Treatment toward Circular Economy and Carbon Neutrality Goals: Pioneering Sustainable and Efficient Solutions for Automation and Advanced Process Control with Smart and Cutting-Edge Technologies. Journal of Water Process Engineering. 63: 105486. https://doi.org/10.1016/j.jwpe.2024.105486.

Rorat, A., P. Courtois, F. Vandenbulcke, and S. Lemiere. 2019. Sanitary and Environmental Aspects of Sewage Sludge Management. In Industrial and Municipal Sludge: Emerging Concerns and Scope for Resource Recovery. 155–180. Amsterdam: Elsevier. https://doi.org/10.1016/B978-0-12-815907-1.00008-8.

Fijalkowski, K., A. Rorat, A. Grobelak, and M. J. Kacprzak. 2017. The Presence of Contaminations in Sewage Sludge—The Current Situation. Journal of Environmental Management. 203: 1126–1136. https://doi.org/10.1016/j.jenvman.2017.05.068.

Appels, L., J. Baeyens, J. Degrève, and R. Dewil. 2008. Principles and Potential of the Anaerobic Digestion of Waste-Activated Sludge. Progress in Energy and Combustion Science. 34(6): 755–781. https://doi.org/10.1016/j.pecs.2008.06.002.

Spinosa, L., et al. 2011. Sustainable and Innovative Solutions for Sewage Sludge Management. Water. 3(2): 702–717. https://doi.org/10.3390/w3020702.

Ferrentino, R., M. Langone, L. Fiori, and G. Andreottola. 2023. Full-Scale Sewage Sludge Reduction Technologies: A Review with a Focus on Energy Consumption. Water. 15(4): 615. https://doi.org/10.3390/w15040615.

Ekane, N., K. Barquet, and A. Rosemarin. 2021. Resources and Risks: Perceptions on the Application of Sewage Sludge on Agricultural Land in Sweden, a Case Study. Frontiers in Sustainable Food Systems. 5: 647780. https://doi.org/10.3389/fsufs.2021.647780.

Liyin, L., H. Yu, Z. Siqi, Y. Donghai, C. Shuxian, and S. Qi. 2023. Worldwide Research Progress and Trend in Sludge Treatment and Disposal: A Bibliometric Analysis. ACS ES&T Engineering. https://doi.org/10.1021/acsestengg.3c00149.

Babcock-Jackson, L., T. Konovalova, J. P. Krogman, R. Bird, and L. L. Díaz. 2023. Sustainable Fertilizers: Publication Landscape on Wastes as Nutrient Sources, Wastewater Treatment Processes for Nutrient Recovery, Biorefineries, and Green Ammonia Synthesis. Journal of Agricultural and Food Chemistry. 71(22): 8265–8296. https://doi.org/10.1021/acs.jafc.3c00454.

Tooraj, M., et al. 2023. Future of Sludge Management. In Sludge Management. London: IntechOpen. https://doi.org/10.5772/intechopen.112984.

Giwa, A. S., N. J. Maurice, A. Luoyan, X. Liu, Y. Yunlong, and Z. Hong. 2023. Advances in Sewage Sludge Application and Treatment: Process Integration of Plasma Pyrolysis and Anaerobic Digestion with the Resource Recovery. Heliyon. 9(9): e19765. https://doi.org/10.1016/j.heliyon.2023.e19765.

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2026-06-16

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Vol. 88 No. 4: July 2026

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Science and Engineering

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