Atıksu Arıtma Çamurlarının Sürdürülebilir Kullanım Alternatifleri: Öncelikli Yaklaşımlar

Yıl 2020, Sayı: 20, 728 - 739, 31.12.2020

Fatma Olcay Topaç , Selnur Uçaroğlu

https://doi.org/10.31590/ejosat.777340

Öz

Atıksu arıtma proseslerindeki mikrobiyal besin zincirinin doğal son ürünleri olan arıtma çamurları, çevre için büyük risk oluşturan atık maddeler arasında sayılmaktadırlar. Arıtma çamurlarının sekonder bir kirletici olarak birikmesi, söz konusu atıkların, işlem gördükten sonra uygun yöntemlerle bertaraf edilmesini zorunlu kılmaktadır. Çamur bertarafı için birçok yöntem bulunmakla birlikte, son yıllarda atıksu arıtma çamurlarının sürdürülebilir kullanımını hedef alan yaklaşımların hem ekonomik, hem de ekolojik açıdan ilgi odağı olduğu görülmektedir. Günümüzün öncelikli yaklaşımları çerçevesinde arıtma çamurları atık bir malzeme olarak düşünülmemekte, geri dönüşümü ya da yeniden kullanımı mümkün olan bir kaynak olarak değerlendirilmektedir. Arıtma çamurlarının yeniden kullanımı kapsamında en yaygın uygulama, stabilize edilen çamurun tarımsal arazilere gübre olarak verilmesidir. Çamurun toprak ortamına girmesiyle, bünyesinde bulunan bitki besin maddeleri ve organik maddeler topraktaki doğal döngülerine katılmakta ve tarımsal üretimde ekonomik kazanç sağlanmaktadır. Ancak son yıllarda yapılan çalışmalar, geleneksel kirleticilerin yanısıra çamurdaki mikrokirleticilerin de çevre ve insan sağlığı için bir tehdit oluşturduğuna dikkati çekmektedir. Bu çalışmaların ortaya koyduğu endişeler, tarım arazilerine yapılan çamur uygulamalarının ölçeğini ve halkın kabulünü kısıtlamaktadır. Bu nedenle, atıksu çamurlarının farklı amaçlarla kullanılmasına yönelik çalışmalara ağırlık verilmiştir. Bu kapsamda, susuzlaştırılmış arıtma çamurları ile çamurların yakılması sonucu elde edilen küller, çimento ve birçok yapı malzemesinin üretiminde katkı maddesi olarak kullanılabilmektedir. Diğer taraftan atıksu çamurundan enerji geri kazanımına yönelik farklı yaklaşımlara sahip pek çok teknoloji geliştirilmiş ve çok sayıda araştırma yapılmıştır. Yakma ve termal enerji geri kazanımı yoluyla elektrik üretimi, atıksu çamuru için popüler bir sürdürülebilir kullanım alternatifi olarak kabul edilmektedir. Ancak çamurun yüksek nem içeriği ve düşük ısıl değeri yüksek enerji tüketimine sebep olmakta ve ek yakıt ihtiyacı söz konusu olabilmektedir. Arıtma çamurlarından elde edilen toplam enerji miktarlarını arttırmak için, kurutma aşamasında harcanan enerjinin azaltılması ve farklı senaryolar ile net enerji dengelerinin sağlanması konularında daha fazla çalışmanın yapılmasına ihtiyaç vardır. Atıksu çamurundan proteinler, enzimler, polihidroksialkanoatlar, biyosürfaktanlar gibi katma değerli ürünlerin elde edilmesi ise, pek çok avantaj sunan ve gelecekteki çamur yönetimi alanında önemli bir yer tutabilecek yenilikçi bir yaklaşımdır. Atıksu çamurundan elde edilebilecek biyo ürünler ve değerli kaynaklar, sürdürülebilir yeşil ürün alternatifleri olarak çok farklı alanlarda kullanılabilme potansiyeline sahiptir. Arıtma çamuru tabanlı biyorafineri süreçlerinin teknolojik-ekonomik performansının daha detaylı olarak ortaya konması için kapsamlı çalışmaların yapılması gerekmektedir.

Anahtar Kelimeler

Atıksu arıtma çamuru, Sürdürülebilir kullanım, Yeniden kullanım, Geri kazanım

Sustainable Utilization Alternatives for Sewage Sludge: Priority Approaches

Öz

Wastewater sludges, which are the natural end products of the microbial food chain in wastewater treatment processes, are among the waste materials that pose a great risk for the environment. The accumulation of sludge as a secondary pollutant obliges those to be disposed by appropriate methods after being treated. Although there are many methods for sludge disposal, it is seen that the approaches targeting the sustainable use of wastewater sludges have been the focus of interest both economically and ecologically. Within the framework of today's priority approaches, sludge is not considered as a waste material, it is considered as a resource that can be recycled or reused. The most common practice among reuse methods is application of stabilized sludge as fertilizer to agricultural lands. With the entry of sludge into the soil environment, the plant nutrients and organic substances in sludge participate in their natural cycles in the soil and economical gain is achieved in agricultural production. However, recent studies draw attention to the fact that micropollutants in wastewater sludge, as well as traditional pollutants, pose a threat to the environment and human health. Concerns raised by these studies limit the scale of sludge applications to agricultural lands and its public acceptance is reduced. Therefore, many studies have been conducted to use sludges for different purposes. In this context, dewatered sludges and sludge ashes can be used as additives in the production of cement as well as many construction materials. Moreover, many technologies with different approaches to energy recovery from wastewater sludge have been developed and many researches have been carried out. Electricity generation through incineration and thermal energy recovery is considered as a popular sustainable usage alternative for wastewater sludge. However, the high moisture content and low calorific value of the sludge cause high energy consumption and additional fuel demand may occur. In order to increase the total amount of energy obtained from the sludge, further work is needed to reduce the energy spent in the drying phase and to achieve net energy balances with different scenarios. Obtaining value-added products such as proteins, enzymes, polyhydroxyalkanoates, and biosurfactants from wastewater sludge is an innovative approach that offers many advantages and can take an important place in the area of sludge management in the future. Bio products and valuable resources that can be obtained from wastewater sludge have the potential to be used in many different areas as sustainable green product alternatives. Comprehensive studies are required to reveal the technological-economic performances of the sludge-based biorefinery processes.

Anahtar Kelimeler

Wastewater sludge, Sustainable Usage, Reuse, Recovery

Kaynakça

• Adar, E., Karatop, B., İnce, M., & Bilgili, M. S. (2016). Comparison of methods for sustainable energy management with sewage sludge in Turkey based on SWOT-FAHP analysis. Renewable and Sustainable Energy Reviews, 62, 429-440. http://dx.doi.org/10.1016/j.rser.2016.05.007.
• Ahmad, A. A., Zawawi, N. A., Kasim, F. H., Inayat, A., & Khasri, A. (2016). Assessing the gasification performance of biomass: A review on biomass gasification process conditions, optimization and economic evaluation. Renewable and Sustainable Energy Reviews, 53, 1333–1347. http://dx.doi.org/10.1016/j.rser.2015.09.030.
• Akaraonye, E., Keshavarz, T., & Roy, I. (2010). Production of polyhydroxyalkanoates: The future green materials of choice. Journal of Chemical Technology and Biotechnology, 85, 732–743. https://doi.org/10.1002/jctb.2392.
• Akat, H., & Altunlu, H. (2019). The effects of sewage sludge applications on growth, yield and flower quality of limonium sinuatum (statice) under salinity conditions. Ege Üniversitesi Ziraat Fakültesi Dergisi, 56(1), 111-120. https://doi.org/ 10.20289/zfdergi.423273.
• Amuda, O. S., Deng, A., Alade, A. O., & Hung Y. T. (2008). Conversion of sewage sludge to biosolids. In L.K. Wang, N.K. Shammas, & Hung Y.T. (Eds.), Biosolids engineering and management. Handbook of environmental engineering, içinde (Bölüm 2), Humana Press.
• Appels, L., Baeyens, J., Degreve, J., & Dewil, R. (2008). Principles and potential of the anaerobic digestion of waste-activated sludge. Progress in Energy and Combustion Science, 34, 755–781. doi:10.1016/j.pecs.2008.06.002.
• Areias, I. O. R., Vieira, C. M. F., Colorado, H. A., Delaqua, G. C. G., Monteiro, S. N., & Azevedo, A. R. G. (2020). Could city sewage sludge be directly used into clay bricks for building construction? A comprehensive case study from Brazil. Journal of Building Engineering, 31, Article 101374. https://doi.org/10.1016/j.jobe.2020.101374.
• Arthurson, V. (2008). Proper sanitization of sewage sludge: A critical issue for a sustainable society. Applied and Environmental Microbiology, 74(17), 5267–5275. https://doi.org/10.1128/AEM.00438-08.
• Atasoy, M., Owusu-Agyemana, I., Plaza, E., & Cetecioglu, Z. (2018). Bio-based volatile fatty acid production and recovery from waste streams: Current status and future challenges. Bioresource Technology, 268, 773-786. https://doi.org/10.1016/j.biortech.2018.07.042.
• Ayol, A., Yurdakos, O. T., & Gurgen, A. (2019). Investigation of municipal sludge gasification potential: Gasification characteristics of dried sludge in a pilot-scale downdraft fixed bed gasifier. International Journal of Hydrogen Energy, 44, 17397-17410. https://doi.org/10.1016/j.ijhydene.2019.01.014.
• Begum, S., Anupoju, G. R., Sridhar, S., Bhargava, S. K., Jegatheesan, V., & Eshtiaghi, N. (2018). Evaluation of single and two stage anaerobic digestion of landfill leachate: effect of pH and initial organic loading rate on volatile fatty acid (VFA) and biogas production. Bioresource Technology, 251, 364-373. https://doi.org/10.1016/j.biortech.2017.12.069.
• Bluemink, E., Van Nieuwenhuijzen, A. F., Wypkema, E., & Uijterlinde, C. A. (2016). Bio-plastic (poly-hydroxy-alkanoate) production from municipal sewage sludge in the Netherlands: A technology push or a demand driven process? Water Science and Technology, 74, 353–358. https://doi.org/10.2166/wst.2016.191.
• Bora, A. P., Gupta, D. P., & Durbha, K. S. (2020). Sewage sludge to bio-fuel: A review on the sustainable approach of transforming sewage waste to alternative fuel. Fuel, 259, Article 116262. https://doi.org/10.1016/j.fuel.2019.116262.
• Cao Y., & Pawlowski A. (2012). Sewage sludge-to-energy approaches based on anaerobic digestion and pyrolysis: Brief overview and energy efficiency assessment. Renewable and Sustainable Energy Reviews, 16(3), 1657-1665. https://doi:10.1016/j.rser.2011.12.014.
• Carrère, H., Dumas, C., Battimelli, A., Batstone, D. J., Delgenès, J. P., Steyer, J. P., & Ferrer, I. (2010). Pretreatment methods to improve sludge anaerobic degradability: a review. Journal of Hazardous Materials, 183, 1–15. https://doi.org/10.1016/j.jhazmat.2010.06.129.
• Cele, E. N., & Maboeta, M. (2016). Response of soil enzyme activities to synergistic effects of biosolids and plants in iron ore mine soils. International Journal of Environmental Science and Technology, 13, 2117–2126. https://doi.org/10.1007/s13762-016-1043-y.
• Chang, Z., Long, G., Zhou, J. L., & Ma, C. (2020). Valorization of sewage sludge in the fabrication of construction and building materials: A review. Resources, Conservation & Recycling, 154, Article 104606. https://doi.org/10.1016/j.resconrec.2019.104606.
• Chen, S., Zhao, Z., Soomro, A., Ma, S., Wu, M., Sun, Z. & Xiang, W. (2020). Hydrogen-rich syngas production via sorption-enhanced steam gasification of sewage sludge. Biomass and Bioenergy, 138, Article 105607. https://doi.org/10.1016/j.biombioe.2020.105607.
• Choi, O. K., Lee, K., Park, K. Y., Kim, J. K., & Lee, J. W. (2017). Pre-recovery of fatty acid methyl ester (FAME) and anaerobic digestion as a biorefinery route to valorizing waste activated sludge. Renewable Energy, 108, 548–554. http://dx.doi.org/10.1016/j.renene.2017.03.004.
• Choi, O. K., Park, J. Y., Kim, J. K., & Lee, J. W. (2019). Bench-scale production of sewage sludge derived-biodiesel (SSD-BD) and upgrade of its quality. Renewable Energy, 141, 914-921. https://doi.org/10.1016/j.renene.2019.04.030.
• Cremades, L. V., Cusidó, J. A., & Arteaga, F. (2018). Recycling of sludge from drinking water treatment as ceramic material for the manufacture of tiles. Journal of Cleaner Production, 201, 1071 – 1080. https://doi.org/10.1016/j.jclepro.2018.08.094.
• Crutchik, D., Franchi, O., Caminos, L., Jeison, D., Belmonte, M., Pedrouso, A., Val del Rio, A., Mosquera-Corral, A., & Campos, J. L. (2020). Polyhydroxyalkanoates (PHAs) Production: A feasible economic option for the treatment of sewage sludge in municipal wastewater treatment plants. Water, 12, Article 1118. https://doi.org/10.3390/w120411187.
• Dahhou, M., El Moussaouiti, M., Arshad, M. A., Moustahsine, S., & Assafi, M. (2018). Synthesis and characterization of drinking water treatment plant sludge-incorporated Portland cement. Journal of Material Cycles and Waste Management, 20, 891-901. https://doi.org/10.1007/s10163-017-0650-0.
• Das, P., Khan, S., AbdulQuadir, M., Thaher, M., Waqas, M., Easa, A., Attia, E. S. M., & Al-Jabri, H. (2020). Energy recovery and nutrients recycling from municipal sewage sludge. Science of the Total Environment, 715, Article 136775. https://doi.org/10.1016/j.scitotenv.2020.136775.
• Dede, G., Özdemir, S., Dede, Ö. H., Altundağ, H., Dündar, M. S, & Kızıloğlu F. T. (2017). Effects of biosolid application on soil properties and kiwi fruit nutrient composition on high-pH soil. International Journal of Environmental Science and Technology, 14, 1451–1458. https://doi.org/10.1007/s13762-017-1252-z.
• Ewais, E., Elsaadany, R., Ahmed, A., Shalaby, N., & Al-Anadouli, B. (2017). Insulating refractory bricks from water treatment sludge and rice husk ash, Refractories and Industrial Ceramics, 58, 136-144. https://doi.org/10.1007/s11148-017-0071-6.
• Fang, P., Tang, Z. J., Huang, J. H., Cen, C. P., Tang, Z. X., & Chen, X. B. (2015). Using sewage sludge as a denitration agent and secondary fuel in a cement plant: A case study. Fuel Processing Technology, 137, 1–7. http://dx.doi.org/10.1016/j.fuproc.2015.03.014.
• Faria, W. M., Figueiredo, C. C., de Coser, T. R., Vale, A. T., & Schneider, B. G. (2018). Is sewage sludge biochar capable of replacing inorganic fertilizers for corn production? Evidence from a two-year field experiment. Archives of Agronomy and Soil Science, 64, 505–519. https://doi.org/10.1080/03650340.2017.1360488.
• Fortela, D. L., Hernandez, R., French, W. T., Zappi, M., Revellame, E., Holmes, W., & Mondala, A. (2016). Extent of inhibition and utilization of volatile fatty acids as carbon sources for activated sludge microbial consortia dedicated for biodiesel production. Renewable Energy, 96, 11-19. https://doi.org/10.1016/j.renene.2016.04.068.
• Gadsbøll, R. Ø., Thomsen, J., Bang-Moller, C., Ahrenfeldt, J., & Henriksen, U. B. (2017). Solid oxide fuel cells powered by biomass gasification for high efficiency power generation. Energy, 131, 198–206. https://doi.org/10.1016/j.energy.2017.05.044.
• Gece, G., & Bilgiç, S. (2010). A theoretical study on the inhibition efficiencies of some amino acids as corrosion inhibitors of nickel. Corrosion Science, 52, 3435–3443. https://doi.org/10.1016/j.corsci.2010.06.015.
• Gholami, A., Mohkam, M., Rasoul-Amini, S., & Ghasemi, Y. (2016). Industrial production of polyhydroxyalkanoates by bacteria: Opportunities and challenges.  Minerva Biotecnologica, 28(1), 59–74.
• Go, L.C., Holmes, W., Depan, D. & Hernandez, R. (2019). Evaluation of extracellular polymeric substances extracted from waste activated sludge as a renewable corrosion inhibitor. PeerJ, 7, Article e7193. https://doi.org/10.7717/peerj.7193.
• González-Corrochano, B., Alonso-Azcárate, J., Rodríguez, L., Lorenzo, A. P., Torío, M. F., Ramos, J. J. T., Corvinos, M. D., & Muro, C. (2017). Effect heating dwell time has on the retention of heavy metals in the structure of lightweight aggregates manufactured from wastes. Environmental Technology, 39, 2511-2523. https://doi.org/10.1080/09593330.2017.1358768.
• Guedes, P., Couto, N., Ottosen, L. M., & Ribeiro, A. B. (2014). Phosphorus recovery from sewage sludge ash through an electrodialytic process. Waste Management, 34, 886-892. https://doi.org/10.1016/j.wasman.2014.02.021.
• Hallas, J. F., Mackowiak, C. L., Wilkie, A. C., & Harris, W. G. (2019). Struvite phosphorus recovery from aerobically digested municipal wastewater. Sustainability, 11, Article 376. https://doi.org/10.3390/su11020376.
• Huang, X., Mu, T., Shen, C.,Lu, L., & Liu, J. (2016). Alkaline fermentation of waste activated sludge stimulated by saponin: volatile fatty acid production, mechanisms and pilot-scale application. Water Science and Technology, 74(12), 2860–2869. https://doi.org/10.2166/wst.2016.459.
• Hwang, J., Zhang, L., Seo, S., Lee, Y. W., & Jahng, D. (2008). Protein recovery from excess sludge for its use as animal feed. Bioresource Technology, 99(18), 8949–8954. https://doi.org/10.1016/j.biortech.2008.05.001.
• Joniec, J. (2018). Enzymatic activity as an indicator of regeneration processes in degraded soil reclaimed with various types of waste. International Journal of Environmental Science and Technology, 15, 2241–2252. https://doi.org/10.1007/s13762-017-1602-x.
• Kacprzak, M., Grobelak, A., Grosser, A., & Prasad, M. N. V. (2014) Efficacy of biosolids in assisted phytostabilization of metalliferous acidic sandy soils with five grass species. International Journal of Phytoremediation, 16(6), 593-60. https://doi.org/ 10.1080/15226514.2013.798625.
• Kakar, F., Koupaie, E. H., Razavi, A. S., Hafez, H., & Elbeshbishy, E. (2020). Effect of hydrothermal pretreatment on volatile fatty acids production from thickened waste activated sludge. Bioenergy Research, 13, 591–604. https://doi.org/10.1007/s12155-019-10056-z.
• Kapanen, A., Vikman, M., Rajasärkkä, J., Virta, M., & Itävaara, M. (2013). Biotests for environmental quality assessment of composted sewage sludge. Waste Management, 33, 1451–1460. https://doi.org/10.1016/j.wasman.2013.02.022.
• Kim, K. R., & Owens, G. (2010). Potential for enhanced phytoremediation of landfills using biosolids – a review. Journal of Environmental Management, 91, 791–797. https://doi.org/10.1016/j.jenvman.2009.10.017.
• Koga, D. (2019). Struvite recovery from digested sewage sludge. In: H. Ohtake, & S. Tsuneda (Eds.), Phosphorus recovery and recycling (pp. 255-264). Springer. Kumar, V., Chopra, A. K., & Kumar, A. (2017). A review on sewage sludge (Biosolids) a resource for sustainable agriculture. Archives of Agriculture and Environmental Science, 2(4), 340-347. https://doi.org/10.26832/24566632.2017.020417.
• Kumar, M., Ghosh, P., Khosla, K., & Thakur, I. S. (2018). Recovery of polyhydroxyalkanoates from municipal secondary wastewater sludges. Bioresource Technology, 255, 111-115. https://doi.org/10.1016/j.biortech.2018.01.031.
• Kumar-Karn, S., & Kumar, A. (2019) Sludge: next paradigm for enzyme extraction and energy generation. Preparative Biochemistry and Biotechnology, 49(2), 105-116. https://doi.org/10.1080/10826068.2019.1566146.
• Lam, C. M., Hsu, S. C., Alvarado, V., & Li, W. M. (2020). Integrated life-cycle data envelopment analysis for techno-environmental performance evaluation on sludge to energy systems. Applied Energy, 266, Article 114867. https://doi.org/10.1016/j.apenergy.2020.114867.
• Lamastra, L., Suciu, N. A., & Trevisan, M. (2018). Sewage sludge for sustainable agriculture: Contaminants’ contents and potential use as fertilizer. Chemical and Biological Technologies in Agriculture 5, Article 10. https://doi.org/10.1186/s40538-018-0122-3.
• Lasaridi, K. E., Manios, T., Stamatiadis, S., Chroni, C., & Kyriacou, A. (2018). The evaluation of hazards to man and the environment during the composting of sewage sludge. Sustainability, 10, Article 2618. https://doi.org/10.3390/su10082618.
• Ledakowicz, S., Stolarek, P., Malinowski, A., & Lepez, O. (2019). Thermochemical treatment of sewage sludge by integration of drying and pyrolysis/autogasification. Renewable and Sustainable Energy Reviews, 104, 319–327. https://doi.org/10.1016/j.rser.2019.01.018.
• Lee, W. S., Chua, A. S. M., Yeoh, H. K., & Ngoh, G. C. (2014) A review of the production and applications of waste-derived volatile fatty acids. Chemical Engineering Journal, 235, 83–99. https://doi.org/10.1016/j.cej.2013.09.002.
• Li, W., Shi, Y., Gao, L., Liu, J., & Cai, Y. (2013). Occurrence, distribution and potential affecting factors of antibiotics in sewage sludge of wastewater treatment plants in China. Science of the Total Environment, 445-446, 306-313. https://doi.org/10.1016/j.scitotenv.2012.12.050.
• Lin, Y. M., Zhou, S. Q., Li, F. Z., & Lin, Y. X. (2012). Utilization of municipal sewage sludge as additives for the production of eco-cement, Journal of Hazardous Materials, 213-214, 457-465. https://doi.org/10.1016/j.jhazmat.2012.02.020.
• Liu, Y., Kong, S., Li, Y., & Zeng, H. (2009). Novel technology for sewage sludge utilization: Preparation of amino acids chelated trace elements (AACTE) fertilizer. Journal of Hazardous Materials, 171, 1159–1167. https://doi.org/10.1016/j.jhazmat.2009.06.123.
• Liu, Z., Norbeck, J. M., Raju, A.S.K., Kim, S., & Park, C.S. (2016). Synthetic natural gas production by sorption enhanced steam hydrogasification based processes for improving CH4 yield and mitigating CO2 emissions. Energy Conversion and Management, 126, 256–265. http://dx.doi.org/10.1016/j.enconman.2016.08.008.
• Liu, H., Li, Y., Fu, B., Guo, H., Zhang, J., & Liu, H. (2020) Chapter 8 - Recovery of volatile fatty acids from sewage sludge through anaerobic fermentation, In S. Varjani, A. Pandey, E. Gnansounou, S.K. Khanal, & S. Raveendran (Eds.), Current developments in biotechnology and bioengineering içinde (pp. 151-177) Elsevier. https://doi.org/10.1016/B978-0-444-64321-6.00008-2.
• Liu, Z., Mayer, B. K., Venkiteshwaran, K., Seyedi, S., Raju, A. S. K., Zitomer, D., & McNamara, P. J. (2020). The state of technologies and research for energy recovery from municipal wastewater sludge and biosolids. Current Opinion in Environmental Science & Health, 14, 31-36. https://doi.org/10.1016/j.coesh.2019.12.004.
• Lu, Q., He, Z. L., & Stoffella, P. J. (2012). Land application of biosolids in the USA: A review. Applied and Environmental Soil Science, Article 201462. https://doi.org/10.1155/2012/201462.
• Martín, J., Camacho-Muñoz, D., Santos, J. L., Aparicio, I., & Alonso, E. (2012). Occurrence of pharmaceutical compounds in wastewater and sludge from wastewater treatment plants: removal and ecotoxicological impact of wastewater discharges and sludge disposal. Journal of Hazardous Materials, 239-240, 40-47. https://doi.org/10.1016/j.jhazmat.2012.04.068.
• Milbrandt, A., Seiple T., Heimiller, D., Skaggs, R., & Coleman, A. (2018). Wet waste-to-energy resources in the United States. Resources, Conservation & Recycling, 137, 32–47. https://doi. org/10.1016/j.resconrec.2018.05.023.
• Militaru, B. A., Pode, R. , Lupa, L., & Manea, F. (2020). Struvite precipitation from sewage sludge ash. Environmental Engineering and Management Journal,19(2), 303-310.
• Minelgaite, A., & Liobikiene, G. (2019). Waste problem in European Union and its influence on waste management behaviours. Science of The Total Environment, 667, 86-93. https://doi.org/10.1016/j.scitotenv.2019.02.313.
• More, T., Yan, S., Hoang, N., Tyagi, R., & Surampalli, R. (2012). Bacterial polymer production using pre-treated sludge as raw material and its flocculation and dewatering potential. Bioresource Technology, 121, 425–431. https://doi.org/10.1016/j.biortech.2012.06.075.
• Morgan-Sagastume, F., Heimersson, S., Laera, G., Werker, A., & Svanström, M. (2016). Techno-environmental assessment of integrating polyhydroxyalkanoate (PHA) production with services of municipal wastewater treatment. Journal of Cleaner Production, 137, 1368–1381. https://doi.org/10.1016/j.jclepro.2016.08.008.
• Munir, M.T., Li, B., Boiarkina, I., Baroutian, S., Yu, W., & Young, B.R. (2017). Phosphate recovery from hydrothermally treated sewage sludge using struvite precipitation. Bioresource Technology, 239, 171-179. . https://doi.org/10.1016/j.biortech.2017.04.129.
• Nakakubo, T., Tokai, A., & Ohno, K. (2012). Comparative assessment of technological systems for recycling sludge and food waste aimed at greenhouse gas emissions reduction and phosphorus recovery. Journal of Cleaner Production, 32, 157-172. https://doi.org/10.1016/j.jclepro.2012.03.026.
• Navarro, A. (2012) Effect of sludge amendment on remediation of metal contaminated soils. Minerals, 2, 473-492. https://doi.org/10.3390/min2040473.
• Pervaiz, M., & Sain, M. (2011). Protein adhesive from sludges. BioResources, 6(2), 961-970.
• Pietzsch, N., Ribeiro, J.L.D., & De Medeiros, J.F. (2017) Benefits, challenges and critical factors of success for Zero Waste: A systematic literature review. Waste Management, 67, 324-353. https://doi.org/10.1016/j.wasman.2017.05.004.
• Placek, A., Grobelak, A., & Kacprzak, M. (2016). Improving the phytoremediation of heavy metals contaminated soil by use of sewage sludges. International Journal of Phytoremediation, 18 (6), 605-618. https://doi.org/10.1080/15226514.2015.1086308.
• Plattes, M., Koehler, C., & Gallé, T. (2017). Purely ultrasonic enzyme extraction from activated sludge in an ultrasonic cleaning bath. MethodsX, 4, 214-217. https://doi.org/10.1016/j.mex.2017.07.003.
• Prajitno, H., Park, J., Ryu, C., Park, H. Y., Lim, H. S., & Kim, J. (2018). Effects of solvent participation and controlled product separation on biomass liquefaction: a case study of sewage sludge. Applied Energy, 218, 402-416. https://doi.org/10.1016/j.apenergy.2018.03.008.
• Romanos, D., Nemer, N., Khairallah, Y., & Abi Saab, M.T. (2019). Assessing the quality of sewage sludge as an agricultural soil amendment in Mediterranean habitats. International Journal of Recycling of Organic Waste in Agriculture, 8, 377–38. https://doi.org/10.1007/s40093-019-00310-x
• Saleh, F., Azizi, H., Kheirandish, F., Bari, M., & Azizi, M. (2015). Media optimization for biosurfactant production by Pseudomonas aeruginosa isolated from activated sludge reservoirs. Petroleum Science and Technology, 33(1), 1-7. https://doi.org/ 10.1080/10916466.2014.942426.
• Salehizadeh, H., & Van Loosdrecht, M.C.M. (2004). Production of polyhydroxyalkanoates by mixed culture: Recent trends and biotechnological importance. Biotechnology Advences, 22, 261–279. https://doi.org/10.1016/j.biotechadv.2003.09.003.
• Samolada, M. C., & Zabaniotou, A. A. (2014). Comparative assessment of municipal sewage sludge incineration, gasification and pyrolysis for a sustainable sludge-to-energy management in Greece. Waste Management, 34, 411–420. http://dx.doi.org/10.1016/j.wasman.2013.11.003.
• Saour, G., Al-Mariri, A., & Hashem, A. (2016). Evaluation of Bacillus thuringiensis cultured in wastewater sludges against the potato tuber moth (Lepidoptera: Gelechiidae). Entomologia Generalis, 36 (2), 149–161. https://doi.org/10.1127/entomologia/2016/0212.
• Semblante, G. U., Hai, F. I., Huang, X., Ball, A. S., Price, W. E., & Nghiem, L. D. (2015). Trace organic contaminants in biosolids: Impact of conventional wastewater and sludge processing technologies and emerging alternatives. Journal of Hazardous Materials, 300, 1-17. https://doi.org/10.1016/j.jhazmat.2015.06.037.
• Shayana, E., Zareb, V., & Mirzaeea, I. (2018). Hydrogen production from biomass gasification; a theoretical comparison of using different gasification agents. Energy Conversion and Management, 159, 30–41. https://doi.org/10.1016/j.enconman.2017.12.096.
• Sim, W. J., Lee, J. W., Shin, S. K., Song, K. B., & Oh, J. E. (2011). Assessment of fates of estrogens in wastewater and sludge from various types of wastewater treatment plants. Chemosphere, 82, 1448-1453. https://doi.org/10.1016/j.chemosphere.2010.11.045.
• Singh, R. P., & Agrawal, M. (2010). Biochemical and physiological responses of rice (Oryza sativa L.) grown on different sewage sludge amendments rates. Bulletin of Environmental Contamination and Toxicology, 84(5), 606-612. https://doi.org/10.1007/s00128-010-0007-z.
• Singh, R., Kumar-Singh, S., & Rathore, D. (2020). Analysis of biosurfactants produced by bacteria growing on textile sludge and their toxicity evaluation for environmental application. Journal of Dispersion Science and Technology, 41(4), 510-522. https://doi.org/ 10.1080/01932691.2019.1592686.
• Su, W., Tang, B., Fu, F., Huang, S., Zhao, S., Bin, L., Ding, J., & Chen, C. (2014). A new insight into resource recovery of excess sewage sludge: Feasibility of extracting mixed amino acids as an environment-friendly corrosion inhibitor for industrial pickling. Journal of Hazardous Materials, 279, 38-45. https://doi.org/10.1016/j.jhazmat.2014.06.053.
• Syazwanee, M., Noormasshela, U. A., Azwady, A. A., Rusea, G., & Muskhazli, M. (2016). Bacillus thuringiensis entomotoxicity activity in wastewater sludge-culture medium towards Bactrocera dorsalis and their histopathological assessment. Sains Malaysiana, 45(4), 589–594.
• Syed-Hassan, S. S. A., Wang, Y., Hu S., Su, S., & Xiang J. (2017). Thermochemical processing of sewage sludge to energy and fuel: fundamentals, challenges and considerations. Renewable and Sustainable Energy Reviews, 80, 888-913. http://dx.doi.org/10.1016/j.rser.2017.05.262.
• Taboada-Santos A., Lema, J. M., & Carballa, M. (2019). Energetic and economic assessment of sludge thermal hydrolysis in novel wastewater treatment plant configurations. Waste Management, 92, 30-38. 2018). https://doi.org/10.1016/j.wasman.
• Tripathi, V., Gaur, V. K., Dhiman, N., Gautam, K., & Manickam, N. (2020). Characterization and properties of the biosurfactant produced by PAH-degrading bacteria isolated from contaminated oily sludge environment. Environmental Science and Pollution Research, 27(22), 27268-27278. https://doi.org/10.1007/s11356-019-05591-3.
• Tsiligiannis, A., & Tsiliyannis, C. (2020). Oil refinery sludge and renewable fuel blends as energy sources for the cement industry. Renewable Energy, 157, 55-70. https://doi.org/10.1016/j.renene.2020.03.129.
• Valderrama, C., Granados, R., & Cortina, J. L. (2013). Stabilisation of dewatered domestic sewage sludge by lime addition as raw material for the cement industry: Understanding process and reactor performance. Chemical Engineering Journal, 232, 458–467. http://dx.doi.org/10.1016/j.cej.2013.07.104.
• Warman, P. R. & Termeer, W. C. (2005). Evaluation of sewage sludge, septic waste and sludge compost applications to corn and forage: Ca, Mg, S, Fe,Mn, Cu, Zn and B content of crops and soils. Bioresource Technology, 96(9), 1029– 1038. https://doi.org/10.1016/j.biortech.2004.09.014.
• Yaman, K., & Olhan, E. (2011). Impact of sewage sludge application on yield, physical input and costs of wheat. Journal of Agrıcultural Sciences-Tarım Bilimleri Dergisi, 17, 157-166.
• Yan, Z., Peng, L., Deng, M., & Lin, J. (2020). Production of a bioflocculant by using activated sludge and its application in Pb(II) removal from aqueous solution. Open Chemistry, 18(1), 333-338. https://doi.org/10.1515/chem-2020-0024.
• Yu, G., He, P., Shao, L., & Zhu, Y. (2009). Enzyme extraction by ultrasound from sludge flocs. Journal of Environmental Sciences, 21(2), 204-210. https://doi.org/10.1016/S1001-0742(08)62252-4.
• Yuan, Q., Sparling, R., & Oleszkiewicz, J.A. (2011) VFA generation from waste activated sludge: Effect of temperature and mixing. Chemosphere, 82, 603-607. https://doi.org/10.1016/j.chemosphere.2010.10.084.
• Zabaniotou, A., & Theofilou, C. (2008). Green energy at cement kiln in Cyprus — Use of sewage sludge as a conventional fuel substitute. Renew. Sustain. Energy Rev., 12, 531–541. doi:10.1016/j.rser.2006.07.017.
• Zhang, X., Yan, S., Tyagi, R. D., & Surampalli, R. Y. (2013). Energy balance and greenhouse gas emissions of biodiesel production from oil derived from wastewater and wastewater sludge. Renewable Energy, 55, 392–403. http://dx.doi.org/10.1016/j.renene.2012.12.046.
• Zhang, L., Xu, C. C., Champagne, P., & Mabee, W. (2014). Overview of current biological and thermochemical treatment Technologies for sustainable sludge management. Waste Management&Research, 32(7), 586-600. http://dx.doi.org/10.1177/0734242X14538303.
• Zhang, W., Alvarez-Gaitan, J. P., Dastyar, W., Saint, C. P., Zhao, M., & Short, M. D. (2018). Value-added products derived from waste activated sludge: A biorefinery perspective. Water, 10, 545. https://doi.org/10.3390/w10050545.
• Zhen, G., Lu, X., Kato, H., Zhao, Y., & Li, Y. Y. (2017). Overview of pretreatment strategies for enhancing sewage sludge disintegration and subsequent anaerobic digestion: current advances, full-scale application and future perspectives. Renewable and Sustainable Energy Reviews, 69, 559–577. http://dx.doi.org/10.1016/j.rser.2016.11.187.
• Zheng, X., Ye, Y., Jiang, Z., Ying, Z., Ji, S., Chen, W., Wang, B., & Dou, B. (2020). Enhanced transformation of phosphorus (P) in sewage sludge to hydroxyapatite via hydrothermal carbonization and calcium-based additive. Science of The Total Environment, 738, Article 139786. https://doi.org/10.1016/j.scitotenv.2020.139786.
• Zhuang, L., Zhou, S., Wang, Y., Liu, Z., & Xu, R. (2011). Cost-effective production of Bacillus thuringiensis biopesticides by solid-state fermentation using wastewater sludge: Effects of heavy metals. Bioresource Technology, 102, 4820–4826. https://doi.org/10.1016/j.biortech.2010.12.098.