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Qi Y, Chen J, Xu H, Wu S, Yang Z, Zhou A, Hao Y. Optimizing sludge dewatering efficiency with ultrasonic Treatment: Insights into Parameters, Effects, and microstructural changes. ULTRASONICS SONOCHEMISTRY 2024; 102:106736. [PMID: 38109798 PMCID: PMC10767495 DOI: 10.1016/j.ultsonch.2023.106736] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2023] [Revised: 12/08/2023] [Accepted: 12/15/2023] [Indexed: 12/20/2023]
Abstract
Sludge dewatering plays a critical role in the efficient and cost-effective management of wastewater treatment plants. Ultrasonic treatment has emerged as a promising technique for improving dewatering processes. This study aims to evaluate the impact of ultrasonic treatment on sludge dewatering characteristics. A series of experiments were conducted to evaluate the dewatering characteristics of sludge under ultrasonic treatment. Experimental data was collected, and the effects of ultrasonic parameters on dewatering efficiency were analyzed. Ultrasound has the capacity to disintegrate sludge flocs, liberate tightly bound water, and enhance sludge dewatering capabilities. The application of ultrasound leads to the breakdown of sludge flocs, which facilitates a substantial amount of organic acids or carbonates. This, in turn, modifies the pH value of the sludge. Additionally, ultrasound induces instantaneous high temperature and pressure within the liquid phase, consequently elevating the temperature of the sludge slurry. Optimum ultrasound energy density and duration of ultrasound treatment exist. For the sludge samples analyzed in this investigation, it was determined that the optimal ultrasonic energy density is 9.8 W, while the optimal duration of ultrasound treatment is 30 s. Excessively escalating the sound energy density or prolonging the duration of ultrasound may yield unfavorable outcomes in terms of sludge dewatering effectiveness. To enhance sludge dewatering, it is crucial to select appropriate ultrasonic energy density and duration of ultrasonic treatment. This study demonstrates the positive impact of ultrasonic treatment on the dewatering characteristics of sludge. The findings provide valuable insights into the potential of ultrasonic technology for enhancing sludge dewatering.
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Affiliation(s)
- Yongzheng Qi
- Jiangsu University of Science and Technology, School of Civil Engineering and Architecture, Zhenjiang 212003, PR China; The National Key Laboratory of Water Disaster Prevention, Nanjing 210029, PR China; Jiangsu Province Engineering Research Center of Geoenvironmental Disaster Prevention and Remediation, Jiangsu, Zhenjiang 212100, PR China.
| | - Jianhao Chen
- Jiangsu University of Science and Technology, School of Civil Engineering and Architecture, Zhenjiang 212003, PR China
| | - Haoqing Xu
- Jiangsu University of Science and Technology, School of Civil Engineering and Architecture, Zhenjiang 212003, PR China; Jiangsu Province Engineering Research Center of Geoenvironmental Disaster Prevention and Remediation, Jiangsu, Zhenjiang 212100, PR China
| | - Silin Wu
- Jiangsu University of Science and Technology, School of Civil Engineering and Architecture, Zhenjiang 212003, PR China; Jiangsu Province Engineering Research Center of Geoenvironmental Disaster Prevention and Remediation, Jiangsu, Zhenjiang 212100, PR China
| | - Ziming Yang
- Jiangsu University of Science and Technology, School of Civil Engineering and Architecture, Zhenjiang 212003, PR China
| | - Aizhao Zhou
- Jiangsu University of Science and Technology, School of Civil Engineering and Architecture, Zhenjiang 212003, PR China; Jiangsu Province Engineering Research Center of Geoenvironmental Disaster Prevention and Remediation, Jiangsu, Zhenjiang 212100, PR China
| | - Yunjie Hao
- Jiangsu University of Science and Technology, School of Civil Engineering and Architecture, Zhenjiang 212003, PR China
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Mostafa A, Elsamadony M, Khalil TE, Elhusseiny AF, Tawfik A, Fujii M, El-Dissouky A, Pant D. Bioelectrochemical system for enhancing anaerobic digestion of pharmaceutical-containing domestic wastewater. CHEMOSPHERE 2023; 339:139766. [PMID: 37562503 DOI: 10.1016/j.chemosphere.2023.139766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2023] [Revised: 08/04/2023] [Accepted: 08/07/2023] [Indexed: 08/12/2023]
Abstract
The unprecedented recent expansion in usage of paracetamol (AAP) has increased the need for suitable wastewater treatment technology. Furthermore, direct interspecies electron transfer promotion (DIET) offers simple and efficient approach for enhancing anaerobic digestion (AD). In this work, using AAP-containing domestic wastewater as feed, control AD reactor (RC) was operated, besides three DIET-promoted AD reactors (REV, RMC and REVMC, referring to electrical voltage "EV"-applied, nFe3O4-multiwall carbon nanotube (MCNT)-supplemented, and "EV applied + MCNT supplemented" reactor, respectively). Maximal treatable organic loading rates by RC, REV, RMC and REVMC were 3.9, 3.9, 7.8 and 15.6 g COD/L/d, corresponding to AAP loading rate of 26, 78, 156 and 312 μg/L/d, respectively. Methane production rate generated by RC, REV, RMC and REVMC reached 0.80 ± 0.01, 0.86 ± 0.04, 1.40 ± 0.07, and 3.01 ± 0.17 L/L/d, respectively. AAP expectedly followed hydroquinone degradation pathway, causing AD failure by acetate accumulation. However, this performance deterioration could be mitigated by DIET-promoted microbes with higher methanogenic activity and advanced electric conductivity. Economic evaluation revealed the favourability of MCNT addition over EV application, since payback periods for RC, REV, RMC and REVMC were 6.2, 7.7, 4.2 and 5.0 yr, respectively.
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Affiliation(s)
- Alsayed Mostafa
- Chemistry Department, Faculty of Science, Alexandria University, Alexandria, Egypt.
| | - Mohamed Elsamadony
- Civil and Environmental Engineering Department, Tokyo Institute of Technology, Meguro-Ku, Tokyo, 152-8552, Japan; Department of Public Works Engineering, Faculty of Engineering, Tanta University, 31521, Tanta, Egypt
| | - Tarek E Khalil
- Chemistry Department, Faculty of Science, Alexandria University, Alexandria, Egypt
| | - Amel F Elhusseiny
- Chemistry Department, Faculty of Science, Alexandria University, Alexandria, Egypt
| | - Ahmed Tawfik
- National Research Centre, Water Pollution Research Department, 12622, Dokki, Cairo, Egypt
| | - Manabu Fujii
- Civil and Environmental Engineering Department, Tokyo Institute of Technology, Meguro-Ku, Tokyo, 152-8552, Japan
| | - Ali El-Dissouky
- Chemistry Department, Faculty of Science, Alexandria University, Alexandria, Egypt
| | - Deepak Pant
- Separation & Conversion Technology, Flemish Institute for Technological Research (VITO), Boeretang 200, Mol, 2400, Belgium
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Mostafa A, Im S, Song YC, Kang S, Shi X, Kim DH. Electrical voltage application as a novel approach for facilitating methanogenic granulation. BIORESOURCE TECHNOLOGY 2022; 360:127632. [PMID: 35863601 DOI: 10.1016/j.biortech.2022.127632] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 07/12/2022] [Accepted: 07/13/2022] [Indexed: 06/15/2023]
Abstract
Despite having high-rate methanogenic performance, up-flow anaerobic sludge blanket reactor still has challenges regarding long-start up period (3-8 months) for granulation. In this study, "electrical voltage (EV, 0.3 V) application" was attempted for facilitating granulation in the continuous operation with increased organic loading rates (0.5-11.0 kg COD/m3/d). Up to 11.0 kg COD/m3/d, EV-reactor exhibited the stable performance, while the control failed. After 49 days of operation (at 7 kg COD/m3/d), the granules collected from EV-reactor had larger diameter (2.3 vs 1.6 mm), higher settling velocity (2.6 vs 1.9 cm/s), and higher hydrophobicity (52.1 % vs 34.5 %), compared to the control. EV application also increased the specific methanogenic activity for propionate and hydrogen almost by two times. The relative abundance of Pseudomonas sp. (quorum sensing (QS)-related microbe) in EV-reactor was 17 % higher than that in the control. In addition, EV application increased the expression of QS genes significantly by 27 times.
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Affiliation(s)
- Alsayed Mostafa
- Department of Smart-city Engineering, Inha University, 100 Inha-ro, Michuhol-gu, Incheon 22212, Republic of Korea
| | - Seongwon Im
- Department of Smart-city Engineering, Inha University, 100 Inha-ro, Michuhol-gu, Incheon 22212, Republic of Korea
| | - Young-Chae Song
- Department of Environmental Engineering, Korea Maritime and Ocean University, Busan 49112, Republic of Korea
| | - Seoktae Kang
- Department of Civil and Environmental Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Xueqing Shi
- School of Environmental and Municipal Engineering, Qingdao University of Technology, Qingdao 266000, PR China
| | - Dong-Hoon Kim
- Department of Smart-city Engineering, Inha University, 100 Inha-ro, Michuhol-gu, Incheon 22212, Republic of Korea.
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Tawfik A, Mostafa A, Elsamadony M, Pant D, Fujii M. Unraveling the metabolic shift in anaerobic digestion pathways associated with the alteration of onion skin waste concentration. ENVIRONMENTAL RESEARCH 2022; 212:113494. [PMID: 35660404 DOI: 10.1016/j.envres.2022.113494] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 05/08/2022] [Accepted: 05/14/2022] [Indexed: 06/15/2023]
Abstract
Onion skin waste (OSW) is common waste in developing countries, which can cause severe environmental pollution when not properly treated. Value-added products can be chemically extracted from OSW; however, that process is not economically feasible. Alternatively, dry anaerobic digestion (DAD) of OSW is a promising approach for both energy recovery and environment protection. The main hurdles during DAD of OSW can be the hydrolysis and acidification. In batch tests, sludge digestate (SD) rich with methanogens was co-digested with different fractions of OSW for enhancing hydrolysis and raising biogas productivity. The cumulative biogas production (CBP) was 36.6 ± 0.3 mL for sole DAD of SD (100% SD) and increased up to 281.9 ± 14.1 mL for (50% SD: 50% OSW) batch. Self-delignification of OSW took place by SD addition, where the lignin removal reached 75.3 ± 10.5% for (85% SD: 15% OSW) batch. Increasing the fraction of OSW (45% SD: 55% OSW) reduced the delignification by a value of 68.8%, where initial lignin concentration was 9.48 ± 1.6% in dry weight. Lignin breaking down resulted a high fraction of phenolic compounds (345.6 ± 58.8 mg gallic acid equivalent/g dry weight) in the fermentation medium, causing CBP drop (219.0 ± 28.5 mL). The presence of elements (K, Ca, Mg, Fe, Zn, Mn, S and P) in OSW improved the enzymatic activity, facilitated phenolic compounds degradation, shifted the metabolism towards acetate fermentation pathway, and raised biogas productivity. Acidogenesis was less affected by phenolic compounds than methanogenesis, causing higher H2 contents and lower CH4 contents, at batches with high share of OSW.
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Affiliation(s)
- Ahmed Tawfik
- National Research Centre, Water Pollution Research Department, 12622, Dokki, Cairo, Egypt
| | - Alsayed Mostafa
- Department of Smart-city Engineering, Inha University, 100 Inharo, Nam-gu, Incheon, 22212, South Korea
| | - Mohamed Elsamadony
- Department of Public Works Engineering, Faculty of Engineering, Tanta University, 31521 Tanta City, Egypt; Department of Civil and Environmental Engineering, Tokyo Institute of Technology, Meguro-Ku, Tokyo, 152-8552, Japan.
| | - Deepak Pant
- Separation & Conversion Technology, Flemish Institute for Technological Research (VITO), Boeretang 200, Mol, 2400, Belgium
| | - Manabu Fujii
- Department of Civil and Environmental Engineering, Tokyo Institute of Technology, Meguro-Ku, Tokyo, 152-8552, Japan
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Banu J R, Varjani S, P S, Tyagi VK, Gunasekaran M. Breakthrough in hydrolysis of waste biomass by physico-chemical pretreatment processes for efficient anaerobic digestion. CHEMOSPHERE 2022; 294:133617. [PMID: 35041820 DOI: 10.1016/j.chemosphere.2022.133617] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 12/19/2021] [Accepted: 01/11/2022] [Indexed: 06/14/2023]
Abstract
Anaerobic digestion (AD) is the most comprehended process to stabilise the waste biomass efficiently and to obtain bioenergy. The AD starts with the hydrolysis process, where the major liability is the action of inhibitors during the hydrolysis process. The biomass pretreatment preceding anaerobic digestion is obligatory to improve feedstock biodegradability for enhanced biogas generation. It can be prevailed by the application of various pretreatment processes. This review explains the major inhibiting compounds and their formation during hydrolysis that affect the efficiency of anaerobic digestion and the benefits of the physico-chemical pretreatment (PCP) method for enhancing hydrolysis in the digestion of waste biomass. The synergistic effect of PCP on macromolecular release, liquefaction and biodegradability were presented. The feasibility of the pretreatment process was evaluated in terms of energy and cost assessment for pilot scale implementation. The outcome of this review reveals that the physico-chemical process is one of the best pretreatment methods to enhance anaerobic digestion by optimising various parameters and increasing the solubilization by about 90%. The thermochemical pretreatment at lower temperature (<100) increases the net energy yield. The solubilization of waste biomass in terms of macromolecular release and liquefaction cannot describe the pretreatment potential. The effectiveness of pretreatment was evaluated by the substrate pre-treatment followed by anaerobic digestibility of pretreated substrate.
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Affiliation(s)
- Rajesh Banu J
- Department of Life Sciences, Central University of Tamil Nadu, Neelakudi, Thiruvarur, 610005, India
| | - Sunita Varjani
- Gujarat Pollution Control Board, Gandhinagar, Gujarat, 382010, India
| | - Sivashanmugam P
- Department of Chemical Engineering, National Institute of Technology, Tiruchirapalli, Tamil Nadu, India
| | - Vinay Kumar Tyagi
- Environmental BioTechnology Group (EBiTG), Department of Civil Engineering, Indian Institute of Technology Roorkee, Roorkee, 247667, India
| | - M Gunasekaran
- Department of Physics, Anna University Regional Campus, Tirunelveli, Tamil Nadu, 627007, India.
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Pilot-Scale Airlift Bioreactor with Function-Enhanced Microbes for the Reduction of Refinery Excess Sludge. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph18136742. [PMID: 34201573 PMCID: PMC8268774 DOI: 10.3390/ijerph18136742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 06/12/2021] [Accepted: 06/18/2021] [Indexed: 11/17/2022]
Abstract
A pilot-scale airlift bioreactor (ALBR) system was built and operated continuously for refinery excess sludge (RES) reduction. Combined ALBR and function-enhanced microbes (composed of photosynthetic bacteria and yeast) were integrated into the system. The pilot-scale ALBR was operated for 62 days, and the start-up time was 7 d. Continuous operation showed that the sludge reduction efficiency was more than 56.22%, and the water quality of the effluent was satisfactory. This study focused on investigating the effects of hydraulic retention time (HRT) on the stability of the system and the effect of sludge reduction. Under different HRT conditions of 40, 26.7, 20, and 16 h, the sludge reduction rates reached 56.22%, 73.24%, 74.09%, and 69.64%, respectively. The removal rates of chemical oxygen demand (COD) and total nitrogen (TN) decreased with decreasing HRT, whereas the removal rate of NH4+-N increased. The removal rate of total phosphorus (TP) was approximately 30%. Results indicate that the ALBR and function-enhanced microbe system can reduce sludge and treat sewage simultaneously, and the effluent is up to the national emission standard. Addition of function-enhanced microbes can promote the degradation of petroleum hydrocarbon substances in the sludge, especially alkanes with low carbon numbers. This study suggests that the optimal HRT for the system is 16 h. The total operation cost of the ALBR combined with the function-enhanced microbe system can be reduced by 50% compared with the cost of direct treatment of the RES system.
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