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Halalsheh M, Shatanawi K, Shawabkeh R, Kassab G, Mohammad H, Adawi M, Ababneh S, Abdullah A, Ghantous N, Balah N, Almomani S. Impact of temperature and residence time on sewage sludge pyrolysis for combined carbon sequestration and energy production. Heliyon 2024; 10:e28030. [PMID: 38596039 PMCID: PMC11002555 DOI: 10.1016/j.heliyon.2024.e28030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Revised: 12/15/2023] [Accepted: 03/11/2024] [Indexed: 04/11/2024] Open
Abstract
Environmental challenges related to sewage sludge call for urgent sustainable management of this resource. Sludge pyrolysis might be considered as a sustainable technology and is anticipated to support measures for mitigating climate change through carbon sequestration. The end products of the process have various applications, including the agricultural utilization of biochar, as well as the energy exploitation of bio-oil and syngas. In this research, sewage sludge was pyrolyzed at 500 °C, 600 °C, 750 °C, and 850 °C. At each temperature, pyrolysis was explored at 1hr, 2hrs, and 3hrs residence times. The ratio (H/Corg)at was tapped to imply organic carbon stability and carbon sequestration potential. Optimum operating conditions were achieved at 750 °C and 2hrs residence time. Produced biochar had (H/Corg)at ratio of 0.54, while nutrients' contents based on dry weight were 3.99%, 3.2%, and 0.6% for total nitrogen (TN), total phosphorus (TP), and total potassium (TK), respectively. Electrical conductivity of biochar was lesser than the feed sludge. Heavy metals in biochar aligned with the recommended values of the International Biochar Initiative. Heat content of condensable and non-condensable volatiles was sufficient to maintain the temperature of the furnace provided that PYREG process is considered. However, additional energy source is demanded for sludge drying.
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Affiliation(s)
- M. Halalsheh
- Water, Energy and Environment Center, The University of Jordan, Amman, Jordan
| | - K. Shatanawi
- Civil Engineering Department, School of Engineering, The University of Jordan, Amman, Jordan
| | - R. Shawabkeh
- Department of Chemical Engineering, School of Engineering, The University of Jordan, Amman, Jordan
| | - G. Kassab
- Civil Engineering Department, School of Engineering, The University of Jordan, Amman, Jordan
| | - H. Mohammad
- Water, Energy and Environment Center, The University of Jordan, Amman, Jordan
| | - M. Adawi
- Water, Energy and Environment Center, The University of Jordan, Amman, Jordan
| | - S. Ababneh
- German Development Cooperation, Amman, Jordan
| | - A. Abdullah
- German Development Cooperation, Amman, Jordan
| | - N. Ghantous
- German Development Cooperation, Amman, Jordan
| | - N. Balah
- German Development Cooperation, Amman, Jordan
| | - S. Almomani
- German Development Cooperation, Amman, Jordan
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2
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K B, Pilli S, Rao PV, Tyagi RD. Predictive modelling of methane yield in biochar-amended cheese whey and septage co-digestion: Exploring synergistic effects using Gompertz and neural networks. CHEMOSPHERE 2024; 353:141558. [PMID: 38417486 DOI: 10.1016/j.chemosphere.2024.141558] [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: 11/23/2023] [Revised: 02/10/2024] [Accepted: 02/24/2024] [Indexed: 03/01/2024]
Abstract
This study performed bench scale studies on anaerobic co-digestion of cheese whey and septage mixed with biochar (BC) as additive at various dosages (0.5 g, 1 g, 2 g and 4 g) and total solids (TS) concentrations (5%, 7.5%, 10%,12.5% and 15%). The experimental results revealed 29.58% increase in methane yield (486 ± 11.32 mL/gVS) with 27% reduction in lag phase time at 10% TS concentration and 50 g/L of BC loading. The mechanistic investigations revealed that BC improved process stability by virtue of its robust buffering capacity and mitigated ammonia inhibition. Statistical analysis indicates BC dosage had a more pronounced effect (P < 0.0001) compared to the impact of TS concentrations. Additionally, the results were modelled using Gompertz model (GM) and artificial neural network (ANN) algorithm, which revealed the outperformance of ANN over GM with MSE 17.96, R2 value 0.9942 and error 0.27%. These findings validated the practicality of utilizing a high dosage of BC in semi-solid anaerobic digestion conditions.
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Affiliation(s)
- Bella K
- Department of Civil Engineering, National Institute of Technology Warangal, Quebec City, QC, Canada
| | - Sridhar Pilli
- Department of Civil Engineering, National Institute of Technology Warangal, Quebec City, QC, Canada
| | - P Venkateswara Rao
- Department of Civil Engineering, National Institute of Technology Warangal, Quebec City, QC, Canada.
| | - R D Tyagi
- BOSK Bio Products, Quebec City, QC, Canada
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3
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Koulouri ME, Templeton MR, Fowler GD. Source separation of human excreta: Effect on resource recovery via pyrolysis. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 338:117782. [PMID: 37015142 DOI: 10.1016/j.jenvman.2023.117782] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 03/13/2023] [Accepted: 03/19/2023] [Indexed: 06/19/2023]
Abstract
More people globally are now using on-site sanitation technologies than sewered connections. The management of faecal sludge generated by on-site facilities is still challenging and requires an understanding of all sanitation service chain components and their interactions; from source conditions to treatment and resource recovery. This study aimed to improve the current lack of knowledge regarding these interactions, by establishing a quantifiable relationship between human excreta source separation and resource recovery via pyrolysis. The effects of source separation of faeces and urine on biochar quality were investigated for different pyrolysis temperatures (450 °C, 550 °C, 650 °C) and this information was used to assess energy and nutrient recovery. Results quantify the benefits of urine diversion for nitrogen recovery (70% of total N losses during thermal treatment avoided) and show an increase in the liming potential of the produced faecal-based biochars. The quality of produced solid fuels is also improved when source-separated faeces (SSF) are used as a feedstock for pyrolysis, including a 50% increase in char calorific value. On the other hand, biochars from mixed urine and faeces (MUF) are more rich in phosphorus and potassium, and surface morphology investigation indicates higher porosity compared to SSF biochars. The high salinity of MUF biochars should be considered before agricultural applications. For both biochar types (SSF, MUF), the presence of phosphate compounds of high fertiliser value was confirmed by X-ray diffraction analysis, and temperatures around 500 °C are recommended to optimise nutrient and carbon behaviour when pyrolysing human excreta. These findings can be used for the design of circular faecal sludge management systems, linking resource recovery objectives to source conditions, and vice-versa. Ultimately, achieving consistent resource recovery from human excreta can act as an incentive for universal access to safe and sustainable sanitation.
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Affiliation(s)
- Maria E Koulouri
- Department of Civil and Environmental Engineering, Imperial College London, SW7 2AZ, UK.
| | - Michael R Templeton
- Department of Civil and Environmental Engineering, Imperial College London, SW7 2AZ, UK.
| | - Geoffrey D Fowler
- Department of Civil and Environmental Engineering, Imperial College London, SW7 2AZ, UK.
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4
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Nicholas HL, Mabbett I, Apsey H, Robertson I. Physico-chemical properties of waste derived biochar from community scale faecal sludge treatment plants. Gates Open Res 2022; 6:96. [PMID: 37564326 PMCID: PMC10409984 DOI: 10.12688/gatesopenres.13727.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/01/2022] [Indexed: 08/12/2023] Open
Abstract
Background: The dumping of untreated faecal sludge from non-sewered onsite sanitation facilities causes environmental pollution and exacerbates poor public health outcomes across developing nations. Long-term mechanisms to treat faecal sludge generated from these facilities are needed to resolve the global sanitation crisis and realize the Sustainable Development Goal (SDG) 6 "ensure availability and sustainable management of water and sanitation for all" by 2030. Pyrolysis of faecal sludge removes pathogens and generates biochar, which can be used as a soil enhancer. Methods: The properties of faecal sludge biochars from three full-scale treatment plants in India were determined via Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), energy dispersive x-ray (EDX) spectroscopy, crystal x-ray diffraction (XRD), proximate analyses, and BET surface area porosimetry. Results: Results showed that all three biochars had low specific surface area, high alkaline pH values, high ash content, and negative surface charge. Fourier transform infrared spectra showed the same surface functional groups present in each biochar. X-ray diffraction analysis showed the mineral composition of each biochar differed slightly. Scanning electron microscopy analysis indicated a porous structure of each biochar with ash particles evident. Conclusions: Slight differences in the ash content, surface area, pH and mineral content was observed between the three biochars.
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Affiliation(s)
- Hannah Larissa Nicholas
- Department of Chemistry, Faculty of Science and Engineering, Swansea University, Swansea, Wales, SA2 8PP, UK
| | - Ian Mabbett
- Department of Chemistry, Faculty of Science and Engineering, Swansea University, Swansea, Wales, SA2 8PP, UK
| | - Henry Apsey
- Department of Chemistry, Faculty of Science and Engineering, Swansea University, Swansea, Wales, SA2 8PP, UK
| | - Iain Robertson
- Department of Geography, Faculty of Science and Engineering, Swansea University, Swansea, Wales, SA2 8PP, UK
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Lu J, Luo Y, Huang J, Hou B, Wang B, Ogino K, Zhao J, Si H. The effect of biochar on the migration theory of nutrient ions. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 845:157262. [PMID: 35820527 DOI: 10.1016/j.scitotenv.2022.157262] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 07/05/2022] [Accepted: 07/06/2022] [Indexed: 06/15/2023]
Abstract
As the acidification of arable soils increases, the utilization of nutrient ions such as N, P, and K decreases substantially. It causes environmental pollution and reduces crop yields. Through previous studies, acidified soil amendments have problems such as easy-retrograde and unclear mechanism. Therefore, in this study, biochar prepared by pyrolysis using peanut shells was used as a green amendment for acidified soil. Biochar with 0, 5 and 10 % biochar ratios were applied to the acidified soil, and the improvement and mechanism were investigated via experiments and software simulations. Analysis of the software simulation results revealed that biochar had the highest unit adsorption of K+ through physical adsorption at 820.38 mg/g. This was followed by PO43-, NO3-, and NH4+ as 270.51, 235.65 and 130.93 mg/g, respectively. These ions were controlled by both electrostatic and ion-exchange adsorption processes. During the improvement, the 10 % biochar ratio group performed the best with a 65.32 % reduction in the outlet volume, and the accumulated levels of nutrient ions in the leachate dropped by 48.40-68.28 % and increased by 437.80-913.87 % in the surface soil. Nutrient ion levels decreased gradually with the increase of soil depth, which agreed with the software simulation results. This study found that applying biochar to acidified soils can provide a solution to low nutrient utilization efficiency and unclear improvement mechanism of acidified soils, and provide a partial theoretical basis for the large-scale application of biochar. Future research on biochar for soil carbon sink and microbial expansion can be strengthened to contribute to environmental protection and multi-level utilization of energy.
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Affiliation(s)
- Jikai Lu
- College of Engineering, Ocean University of China, 239 Song-ling Road, Qingdao 266100, Shandong, China; Shandong Key Laboratory of Biomass Gasification Technology, Energy Research Institute, Qilu University of Technology (Shandong Academy of Sciences), 19 Ke-yuan Road, Jinan 250014, Shandong, China
| | - Yina Luo
- College of Engineering, Ocean University of China, 239 Song-ling Road, Qingdao 266100, Shandong, China
| | - Junlin Huang
- College of Engineering, Ocean University of China, 239 Song-ling Road, Qingdao 266100, Shandong, China
| | - Bingyan Hou
- College of Engineering, Ocean University of China, 239 Song-ling Road, Qingdao 266100, Shandong, China
| | - Bing Wang
- Shandong Key Laboratory of Biomass Gasification Technology, Energy Research Institute, Qilu University of Technology (Shandong Academy of Sciences), 19 Ke-yuan Road, Jinan 250014, Shandong, China; Graduate School of Bio-Applications and Systems Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Nakacho, Koganei-shi, Tokyo 184-8588, Japan.
| | - Kenji Ogino
- Graduate School of Bio-Applications and Systems Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Nakacho, Koganei-shi, Tokyo 184-8588, Japan
| | - Jian Zhao
- College of Engineering, Ocean University of China, 239 Song-ling Road, Qingdao 266100, Shandong, China.
| | - Hongyu Si
- Shandong Key Laboratory of Biomass Gasification Technology, Energy Research Institute, Qilu University of Technology (Shandong Academy of Sciences), 19 Ke-yuan Road, Jinan 250014, Shandong, China.
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Rowles LS, Morgan VL, Li Y, Zhang X, Watabe S, Stephen T, Lohman HAC, DeSouza D, Hallowell J, Cusick RD, Guest JS. Financial Viability and Environmental Sustainability of Fecal Sludge Treatment with Pyrolysis Omni Processors. ACS ENVIRONMENTAL AU 2022; 2:455-466. [PMID: 36164351 PMCID: PMC9502014 DOI: 10.1021/acsenvironau.2c00022] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/10/2022] [Revised: 07/11/2022] [Accepted: 07/11/2022] [Indexed: 11/30/2022]
Abstract
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Omni Processors (OPs) are community-scale systems for
non-sewered
fecal sludge treatment. These systems have demonstrated their capacity
to treat excreta from tens of thousands of people using thermal treatment
processes (e.g., pyrolysis), but their relative sustainability is
unclear. In this study, QSDsan (an open-source Python package) was
used to characterize the financial viability and environmental implications
of fecal sludge treatment via pyrolysis-based OP technology treating
mixed and source-separated human excreta and to elucidate the key
drivers of system sustainability. Overall, the daily per capita cost
for the treatment of mixed excreta (pit latrines) via the OP was estimated
to be 0.05 [0.03–0.08] USD·cap–1·d–1, while the treatment of source-separated excreta
(from urine-diverting dry toilets) was estimated to have a per capita
cost of 0.09 [0.08–0.14] USD·cap–1·d–1. Operation and maintenance of the OP is a critical
driver of total per capita cost, whereas the contribution from capital
cost of the OP is much lower because it is distributed over a relatively
large number of users (i.e., 12,000 people) for the system lifetime
(i.e., 20 yr). The total emissions from the source-separated scenario
were estimated to be 11 [8.3–23] kg CO2 eq·cap–1·yr–1, compared to 49 [28–77]
kg CO2 eq·cap–1·yr–1 for mixed excreta. Both scenarios fall below the estimates of greenhouse
gas (GHG) emissions for anaerobic treatment of fecal sludge collected
from pit latrines. Source-separation also creates opportunities for
resource recovery to offset costs through nutrient recovery and carbon
sequestration with biochar production. For example, when carbon is
valued at 150 USD·Mg–1 of CO2, the
per capita cost of sanitation can be further reduced by 44 and 40%
for the source-separated and mixed excreta scenarios, respectively.
Overall, our results demonstrate that pyrolysis-based OP technology
can provide low-cost, low-GHG fecal sludge treatment while reducing
global sanitation gaps.
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Affiliation(s)
- Lewis Stetson Rowles
- Institute for Sustainability, Energy, and Environment, University of Illinois Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Victoria L. Morgan
- Institute for Sustainability, Energy, and Environment, University of Illinois Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Yalin Li
- Institute for Sustainability, Energy, and Environment, University of Illinois Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Xinyi Zhang
- Department of Civil & Environmental Engineering, University of Illinois Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Shion Watabe
- Department of Civil & Environmental Engineering, University of Illinois Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Tyler Stephen
- Department of Civil & Environmental Engineering, University of Illinois Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Hannah A. C. Lohman
- Department of Civil & Environmental Engineering, University of Illinois Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Derek DeSouza
- Biomass Controls PBC, Woodstock, Connecticut 06281, United States
| | - Jeff Hallowell
- Biomass Controls PBC, Woodstock, Connecticut 06281, United States
| | - Roland D. Cusick
- Department of Civil & Environmental Engineering, University of Illinois Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Jeremy S. Guest
- Institute for Sustainability, Energy, and Environment, University of Illinois Urbana−Champaign, Urbana, Illinois 61801, United States
- Department of Civil & Environmental Engineering, University of Illinois Urbana−Champaign, Urbana, Illinois 61801, United States
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7
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Madadian E, Simakov DSA. Thermal degradation of emerging contaminants in municipal biosolids: The case of pharmaceuticals and personal care products. CHEMOSPHERE 2022; 303:135008. [PMID: 35643167 DOI: 10.1016/j.chemosphere.2022.135008] [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: 02/15/2022] [Revised: 05/01/2022] [Accepted: 05/16/2022] [Indexed: 06/15/2023]
Abstract
The presence of emerging contaminants in water and wastewater resources is of ongoing concern for public health and safety. Pharmaceutical compounds are designed to be biologically active and therefore may have effects on nontarget organisms in terrestrial and aquatic environments, even at trace concentrations. The presence of pharmaceutical and personal care products (PPCPs) in wastewater treatment plants is reported in various countries worldwide, mostly in the levels of nanograms to micrograms per litre. The present study investigates the thermal degradation of municipal sewage sludge containing PPCPs at various heating rates. The examined characteristics of the samples include thermal decomposition behavior, volatile release characteristics, and pyrolytic product composition. Thermal characterization of the PPCPs was conducted using differential scanning calorimetry. The gaseous products and typical functional groups of the released volatiles detected by Fourier-transform infrared spectroscopy mainly contained CO2, CO, small-chain hydrocarbons, and oxygen- and nitrogen-containing functional groups together with other species. In addition, the potential of bioenergy production was investigated as a spin-off opportunity during thermal degradation of biosolids. Study results showed that PPCP concentrations can be lowered significantly by thermal treatment of municipal biosolids. Antifungal/antibacterial agents together with opioids, in particular triclosan and tramadol, showed less resistance to thermal degradation while antibiotics could be more recalcitrant to heat treatment. The thermodynamic results provide an important reference for future reactor design and the thermochemical treatment of biosolids as well as their conversion to value-added products.
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Affiliation(s)
- Edris Madadian
- Department of Chemical Engineering, University of Waterloo, Waterloo, ON, N2L 3G1, Canada.
| | - David S A Simakov
- Department of Chemical Engineering, University of Waterloo, Waterloo, ON, N2L 3G1, Canada
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8
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Nicholas HL, Mabbett I, Apsey H, Robertson I. Physico-chemical properties of waste derived biochar from community scale faecal sludge treatment plants. Gates Open Res 2022. [DOI: 10.12688/gatesopenres.13727.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Background: The dumping of untreated faecal sludge from non-sewered onsite sanitation facilities causes environmental pollution and exacerbates poor public health outcomes across developing nations. Long-term mechanisms to treat faecal sludge generated from these facilities are needed to resolve the global sanitation crisis and realize the Sustainable Development Goal (SDG) 6 “ensure availability and sustainable management of water and sanitation for all” by 2030. Pyrolysis of faecal sludge removes pathogens and generates biochar, which can be used as a soil enhancer. Methods: The properties of faecal sludge biochars from three full-scale treatment plants in India were determined via Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), energy dispersive x-ray (EDX) spectroscopy, crystal x-ray diffraction (XRD), proximate analyses, and BET surface area porosimetry. Results: Results showed that all three biochars had low specific surface area, high alkaline pH values, high ash content, and negative surface charge. Fourier transform infrared spectra showed the same surface functional groups present in each biochar. X-ray diffraction analysis showed the mineral composition of each biochar differed slightly. Scanning electron microscopy analysis indicated a porous structure of each biochar with ash particles evident. Conclusions: Slight differences in the ash content, surface area, pH and mineral content was observed between the three biochars.
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9
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Mamera M, van Tol JJ, Aghoghovwia MP. Treatment of faecal sludge and sewage effluent by pinewood biochar to reduce wastewater bacteria and inorganic contaminants leaching. WATER RESEARCH 2022; 221:118775. [PMID: 35803045 DOI: 10.1016/j.watres.2022.118775] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 05/14/2022] [Accepted: 06/16/2022] [Indexed: 06/15/2023]
Abstract
Biochar is a valuable treatment option for faecal sludge management (FSM). However, the sanitation application rates of biochar in FSM are not well established. There is also a gap in knowledge about the effect of actual raw sewage effluent and sludge on organic and inorganic contaminants migration of biochar treated soil. This study investigated the concentration and migration rates of N, P, E. coli and faecal coliform bacteria through different soil-bed biochar column treatments leached with raw faecal sludge and sewage effluent. Forty-four soil-bed leaching columns with pinewood biochar rates at 5, 10 and 20 t/ha were set at the Bloemspruit wastewater plant, South Africa. The pinewood biochar used had a pH of 10.21, total C composition of 92%, surface area of 517 m²/g, and a pore size of 1.7 nm. It was found that the 20 t biochar per ha treatment with faecal sludge increased water retention (flows of 33 mm/h. at 0 t/ha compared to 0.8 mm/h. at 20 t/ha) and leachates purification. High detections were observed for faecal coliforms and E.coli above 4331 CFU/100 mL from the effluent and faecal sludge in soils without biochar. Detection of E.coli at 20 t/ha decreased to 1 CFU/100 mL while the faecal coliforms still had counts above 10 CFU/ 100 mL. The results showed a decreasing rate of nitrates, phosphates, zinc and copper with an increasing biochar application rate. Pinewood biochar showed significant removal efficiencies of bacteria (between 89 and 98%) and nitrates and phosphates (between 68 and 98%). Significant differences were seen at P < 0.05 between the means of the treatments with and without biochar. The results from the study show that pinewood biochar applied at rates between 5 and 20 t/ha has a high organic and inorganic contaminants reduction potential for FSM.
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Affiliation(s)
- Matthew Mamera
- Department of Soil, Crop and Climate Sciences, Faculty of Natural Sciences, University of the Free State, Bloemfontein 9301, South Africa.
| | - Johan J van Tol
- Department of Soil, Crop and Climate Sciences, Faculty of Natural Sciences, University of the Free State, Bloemfontein 9301, South Africa
| | - Makhosazana P Aghoghovwia
- Department of Soil, Crop and Climate Sciences, Faculty of Natural Sciences, University of the Free State, Bloemfontein 9301, South Africa
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10
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Performance and mechanism of As(III/Ⅴ) removal from aqueous solution by novel positively charged animal-derived biochar. Sep Purif Technol 2022. [DOI: 10.1016/j.seppur.2022.120836] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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11
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Kabir SB, Khalekuzzaman M, Hossain N, Jamal M, Alam MA, Abomohra AEF. Progress in biohythane production from microalgae-wastewater sludge co-digestion: An integrated biorefinery approach. Biotechnol Adv 2022; 57:107933. [DOI: 10.1016/j.biotechadv.2022.107933] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 01/30/2022] [Accepted: 02/25/2022] [Indexed: 12/30/2022]
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12
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Potential Use of Biochar in Pit Latrines as a Faecal Sludge Management Strategy to Reduce Water Resource Contaminations: A Review. APPLIED SCIENCES-BASEL 2021. [DOI: 10.3390/app112411772] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Faecal sludge management (FSM) in most developing countries is still insufficient. Sanitation challenges within the sub-Saharan region have led to recurring epidemics of water- and sanitation-related diseases. The use of pit latrines has been recognised as an option for on-site sanitation purposes. However, there is also concern that pit latrine leachates may cause harm to human and ecological health. Integrated approaches for improved access to water and sanitation through proper faecal sludge management are needed to address these issues. Biochar a carbon-rich adsorbent produced from any organic biomass when integrated with soil can potentially reduce contamination. The incorporation of biochar in FSM studies has numerous benefits in the control of prospective contaminants (i.e., heavy metals and inorganic and organic pollutants). This review paper evaluated the potential use of biochar in FSM. It was shown from the reviewed articles that biochar is a viable option for faecal sludge management because of its ability to bind contaminants. Challenges and possible sustainable ways to incorporate biochar in pit latrine sludge management were also illustrated. Biochar use as a low-cost adsorbent in wastewater contaminant mitigation can improve the quality of water resources. Biochar-amended sludge can also be repurposed as a useful economical by-product.
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13
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Krueger BC, Fowler GD, Templeton MR, Septien S. Faecal sludge pyrolysis: Understanding the relationships between organic composition and thermal decomposition. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2021; 298:113456. [PMID: 34364246 DOI: 10.1016/j.jenvman.2021.113456] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 07/26/2021] [Accepted: 07/30/2021] [Indexed: 06/13/2023]
Abstract
Sludge treatment is an integral part of faecal sludge management in non-sewered sanitation settings. Development of pyrolysis as a suitable sludge treatment method requires thorough knowledge about the properties and thermal decomposition mechanisms of the feedstock. This study aimed to improve the current lack of understanding concerning relevant sludge properties and their influence on the thermal decomposition characteristics. Major organic compounds (hemicellulose, cellulose, lignin, protein, oil and grease, other carbohydrates) were quantified in 30 faecal sludge samples taken from different sanitation technologies, providing the most comprehensive organic faecal sludge data set to date. This information was used to predict the sludge properties crucial to pyrolysis (calorific value, fixed carbon, volatile matter, carbon, hydrogen). Samples were then subjected to thermogravimetric analysis to delineate the influence of organic composition on thermal decomposition. Septic tanks showed lower median fractions of lignin (9.4%dwb) but higher oil and grease (10.7%dwb), compared with ventilated improved pit latrines (17.4%dwb and 4.6%dwb respectively) and urine diverting dry toilets (17.9%dwb and 4.7%dwb respectively). High fixed carbon fractions in lignin (45.1%dwb) and protein (18.8%dwb) suggested their importance for char formation, while oil and grease fully volatilised. For the first time, this study provided mechanistic insights into faecal sludge pyrolysis as a function of temperature and feedstock composition. Classification into the following three phases was proposed: decomposition of hemicellulose, cellulose, other carbohydrates, proteins and, partially, lignin (200-380 °C), continued decomposition of lignin and thermal cracking of oil and grease (380-500 °C) and continued carbonisation (>500 °C). The findings will facilitate the development and optimisation of faecal sludge pyrolysis, emphasising the importance of considering the organic composition of the feedstock.
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Affiliation(s)
- Benedict C Krueger
- Department of Civil and Environmental Engineering, Imperial College London, SW7 2AZ, UK.
| | - Geoffrey D Fowler
- Department of Civil and Environmental Engineering, Imperial College London, SW7 2AZ, UK
| | - Michael R Templeton
- Department of Civil and Environmental Engineering, Imperial College London, SW7 2AZ, UK
| | - Santiago Septien
- Water, Sanitation & Hygiene Research & Development Centre, University of KwaZulu-Natal, Durban, 4041, South Africa
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14
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Fe(NO3)3 assisted hydrothermal carbonization of sewage sludge: Focusing on characteristics of hydrochar and aqueous phase. MOLECULAR CATALYSIS 2021. [DOI: 10.1016/j.mcat.2021.111823] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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15
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Yan R, Cheng S, Chen J, Li X, Sharma S, Nazim Uddin SM, Mang HP, Chen C, Li Z, Li T, Wang X. Operating status of public toilets in the Hutong neighborhoods of Beijing: An empirical study. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2021; 287:112252. [PMID: 33714043 PMCID: PMC8075803 DOI: 10.1016/j.jenvman.2021.112252] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 02/10/2021] [Accepted: 02/20/2021] [Indexed: 06/12/2023]
Abstract
The provision of sanitation services for fast-growing urban populations is one of the world's urgent challenges. Hutong neighborhoods in Beijing, capital of China, cannot be rebuilt due to the protection of historical heritage, while residents still need to keep the habit of defecating in public toilets. One hundred public toilets with non-sewered sanitation in the Hutong neighborhoods of Beijing were visited to investigate the actual operating status in response to the "toilet revolution" campaign. The fault tree approach was used to identify the barriers toward a decent and environment-friendly public toilet and evaluate potential risks from the malfunction of various components. Four subsystems are defined and elaborated to calculate the fault possibility. These subsystems are environment- and user-friendly, regarded as ancillary facilities, and used for fecal sludge (FS) management. Statistical analysis of targeted cases indicated that fault probabilities of environmental considerations, user-friendly considerations, ancillary facilities, FS management are calculated as 0.79, 0.96, 0.96, and 0, respectively. The subsystems were weighted using a Delphi method concept. Results showed that the well operation ratio of Beijing Hutong public toilets is only 32%, and the sanitation service value chain can be further optimized. This study also provides references for other countries, which are dedicated to promoting urban sanitation and public health.
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Affiliation(s)
- Rui Yan
- School of Energy and Environmental Engineering, Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Xueyuan Road No.30, Haidian District, Beijing, 100083, PR China.
| | - Shikun Cheng
- School of Energy and Environmental Engineering, Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Xueyuan Road No.30, Haidian District, Beijing, 100083, PR China.
| | - Jingang Chen
- School of Energy and Environmental Engineering, Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Xueyuan Road No.30, Haidian District, Beijing, 100083, PR China.
| | - Xiangkai Li
- School of Energy and Environmental Engineering, Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Xueyuan Road No.30, Haidian District, Beijing, 100083, PR China.
| | - Sumit Sharma
- Cologne University of Applied Science, Hahnen Str. 31c, 50354, Huerth-Efferen, Germany.
| | | | - Heinz-Peter Mang
- German Toilet Organization, Paulsenstr. 23/12163, Berlin, Germany.
| | - Cong Chen
- School of Economics and Management, University of Science and Technology Beijing, Xueyuan Road No.30, Haidian District, Beijing, 100083, PR China.
| | - Zifu Li
- School of Energy and Environmental Engineering, Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Xueyuan Road No.30, Haidian District, Beijing, 100083, PR China.
| | - Tianxin Li
- School of Energy and Environmental Engineering, Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Xueyuan Road No.30, Haidian District, Beijing, 100083, PR China.
| | - Xuemei Wang
- School of Energy and Environmental Engineering, Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Xueyuan Road No.30, Haidian District, Beijing, 100083, PR China.
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16
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One Year Residual Effect of Sewage Sludge Biochar as a Soil Amendment for Maize in a Brazilian Oxisol. SUSTAINABILITY 2021. [DOI: 10.3390/su13042226] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The thermochemical transformation of sewage sludge (SS) to biochar (SSB) allows exploring the advantages of SS and reduces possible environmental risks associated with its use. Recent studies have shown that SSB is nutrient-rich and may replace mineral fertilizers. However, there are still some questions to be answered about the residual effect of SSB on soil nutrient availability. In addition, most of the previous studies were conducted in pots or soil incubations. Therefore, the residual effect of SSB on soil properties in field conditions remains unclear. This study shows the results of nutrient availability and uptake as well as maize yield the third cropping of a three-year consecutive corn cropping system. The following treatments were compared: (1) control: without mineral fertilizer and biochar; (2) NPK: with mineral fertilizer; (3) SSB300: with biochar produced at 300 °C; (4) SSB300+NPK; (5) SSB500: with biochar produced at 500 °C; and (6) SSB500+NPK. The results show that SSB has one-year residual effects on soil nutrient availability and nutrient uptake by maize, especially phosphorus. Available soil P contents in plots that received SSB were around five times higher than the control and the NPK treatments. Pyrolysis temperature influenced the SSB residual effect on corn yield. One year after suspending the SSB application, SSB300 increased corn yield at the same level as the application of NPK. SSB300 stood out and promoted higher grain yield in the residual period (8524 kg ha−1) than SSB500 (6886 kg ha−1). Regardless of pyrolysis temperature, biochar boosted the mineral fertilizer effect resulting in higher grain yield than the exclusive application of NPK. Additional long-term studies should be focused on SSB as a slow-release phosphate fertilizer.
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17
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Krueger BC, Fowler GD, Templeton MR. Critical analytical parameters for faecal sludge characterisation informing the application of thermal treatment processes. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2021; 280:111658. [PMID: 33246749 DOI: 10.1016/j.jenvman.2020.111658] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 10/22/2020] [Accepted: 11/06/2020] [Indexed: 06/12/2023]
Abstract
Thermal processes for the treatment of faecal sludge such as pyrolysis or combustion offer complete destruction of pathogens, whilst allowing for energy and nutrient recovery. The development of such processes is currently constrained by a lack of knowledge on thermally relevant faecal sludge characteristics. This study investigated thirty faecal sludge samples from three sanitation technologies (ventilated improved pit latrines (VIP), urine diverting dry toilets (UD), septic tanks (ST)) and compared these by non-parametric statistical analysis. A focus was placed on parameters necessary for thermal process development and recoverable nutrient concentrations. The relevant characteristics ranged widely within technology groups. Calorific values and ash concentrations of 2.1-25.7 MJ/kg and 9.5-88.4% were observed for STs, of 9.2-13.9 MJ/kg and 40.9-61.5% for VIPs and of 3.9-18.1 MJ/kg and 18.8-81.3% for UDs. These two parameters show a strong linear inverse correlation and determine the minimum dewatering requirements from which a net energy recovery may be possible. Results suggest that more than 90% of samples can meet these requirements following commonly used dewatering technologies. A comparison across technologies provided strong evidence that the faecal sludge source significantly influences sludge composition, emphasized by higher median ratios of fixed carbon to volatile matter in VIPs (0.23) and UDs (0.23) compared to STs (0.15). The sanitation technology also influenced recoverable nutrient concentrations, with phosphorus and potassium concentrations generally ranging between 5.8-49.2 g/kg and 1.4-26.1 g/kg respectively. Compared to STs, median concentrations of phosphorus and potassium in VIPs were 3.4 and 3.8 times higher respectively, and 3.0 and 8.8 times higher in UDs. The findings highlight the importance of considering the faecal sludge source in the development of thermal treatment processes. This study provides critical knowledge to further develop such processes through modelling, experimental and scaled approaches.
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Affiliation(s)
- Benedict C Krueger
- Department of Civil and Environmental Engineering, Imperial College London, SW7 2AZ, UK.
| | - Geoffrey D Fowler
- Department of Civil and Environmental Engineering, Imperial College London, SW7 2AZ, UK
| | - Michael R Templeton
- Department of Civil and Environmental Engineering, Imperial College London, SW7 2AZ, UK
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18
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Sun Z, Wang Y, Chen X, Zhu N, Yuan H, Lou Z. Variation of dissolved organic matter during excess sludge reduction in microbubble ozonation system. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:6090-6098. [PMID: 32989695 DOI: 10.1007/s11356-020-10799-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 09/09/2020] [Indexed: 06/11/2023]
Abstract
Sewage sludge is the major by-product of wastewater treatment plants, and about 30% readily biodegradable organic matters might be reused through the mass reduction process, which could be also reduced the disposal fee. In this study, the microbubble ozonation (MB-O3) was employed to improve the oxidation efficiency for sludge solubilization. At 160 mgO3/gSS, the maximum mixed liquor suspended solids (MLSS) reduction ratio was 37.5% and the protein and polysaccharide contents increased to 31.6 and 138.6 mg/L, respectively. It was proposed that aromatic protein and soluble microbial in sludge were oxidized preferentially by MB-O3, and the dissolved organic matter (DOM) fractions (mainly humic-acid-like substances) exhibited low degradability according to the variations of fluorescence excitation-emission spectrum coupled with fluorescence regional integration. MB-O3 could enhance the settleability, but deteriorate sludge dewaterability at low dosage (< 160 mgO3/gSS) due to a reduction in particle size from 61.7 to 47.5 μm. MB-O3 has a good performance on the mass reduction of sludge through the improvement of the radical generated.
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Affiliation(s)
- Zhiyi Sun
- Shanghai Engineering Research Center of Solid Waste Treatment and Recycling, School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Yuxiang Wang
- Shanghai Engineering Research Center of Solid Waste Treatment and Recycling, School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Xiaoliang Chen
- Shanghai Solid Waste Management Center, Shanghai, 200235, China
| | - Nanwen Zhu
- Shanghai Engineering Research Center of Solid Waste Treatment and Recycling, School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, China
| | - Haiping Yuan
- Shanghai Engineering Research Center of Solid Waste Treatment and Recycling, School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Ziyang Lou
- Shanghai Engineering Research Center of Solid Waste Treatment and Recycling, School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China.
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, China.
- China Institute for Urban Governance, Shanghai Jiao Tong University, Shanghai, 200240, China.
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19
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Zhang Z, Hu M, Bian B, Yang Z, Yang W, Zhang L. Full-scale thermophilic aerobic co-composting of blue-green algae sludge with livestock faeces and straw. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 753:142079. [PMID: 32911176 DOI: 10.1016/j.scitotenv.2020.142079] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Revised: 08/25/2020] [Accepted: 08/28/2020] [Indexed: 06/11/2023]
Abstract
A high incidence of harmful algal bloom in eutrophic surface waters causes many environmental problems. Thermophilic aerobic composting enables effective treatment and disposal of algal sludge that remains after the dewatering of algae slurries, and provides a value-added organic fertiliser. Previous studies have either only dealt with the composting of a single waste component or were conducted at a lab-/pilot-scale; however, this work is a comprehensive assessment of full-scale mechanized thermophilic aerobic co-composting of algal sludge and other typical biomass-based wastes, including chicken faeces and rice straw, in a water-rich rural area in the Tai lake basin, China. With the optimised feedstock material mass ratio (6.0:1.8:1.0 for straw:algae:faeces; initial C/N ratio of 20; and initial moisture of 60 wt%), the co-composting process effectively achieved the reduction, harmlessness, and reuse of waste. The moisture content (28.36 wt% of wet weight), organic matter content (57.91 wt% of dried weight), total nutrient content (6.59 wt% for TN + TP + TK of dried weight), and heavy metal contents as well as the pH of the final product fully met the Chinese National Agricultural Organic Fertiliser Standard requirements. The reduction rates of microcystin and toxic volatile fatty acid contents were higher than 99.5%, and the seed germination index of the product was 114.5%. A notable economic benefit with a gross profit margin of 167-434% of the process was highlighted. Investigation of the associated mechanisms, including statistical analysis, spectral characterisation, micro-morphological observation, and microbial community analysis, revealed that a decreased particle sizes with a looser structure and an efficient humification effect, resulting from the work of several identified dominant microbial species, contributed to the high product quality. The current study provided a demonstration of the promising full-scale co-composting technology for comprehensive management of the environment in water-rich rural areas and the construction of a sustainable watershed.
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Affiliation(s)
- Zepeng Zhang
- School of Chemistry and Materials Science, School of Environment, Jiangsu Provincial Key Laboratory of Material Cycling and Pollution Control, Nanjing Normal University, Nanjing 210046, PR China
| | - Min Hu
- School of Chemistry and Materials Science, School of Environment, Jiangsu Provincial Key Laboratory of Material Cycling and Pollution Control, Nanjing Normal University, Nanjing 210046, PR China
| | - Bo Bian
- School of Chemistry and Materials Science, School of Environment, Jiangsu Provincial Key Laboratory of Material Cycling and Pollution Control, Nanjing Normal University, Nanjing 210046, PR China
| | - Zhen Yang
- School of Chemistry and Materials Science, School of Environment, Jiangsu Provincial Key Laboratory of Material Cycling and Pollution Control, Nanjing Normal University, Nanjing 210046, PR China.
| | - Weiben Yang
- School of Chemistry and Materials Science, School of Environment, Jiangsu Provincial Key Laboratory of Material Cycling and Pollution Control, Nanjing Normal University, Nanjing 210046, PR China.
| | - Limin Zhang
- School of Chemistry and Materials Science, School of Environment, Jiangsu Provincial Key Laboratory of Material Cycling and Pollution Control, Nanjing Normal University, Nanjing 210046, PR China
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20
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Zhang Y, Zhang Z, Liu W, Chen Y. New applications of quinone redox mediators: Modifying nature-derived materials for anaerobic biotransformation process. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 744:140652. [PMID: 32693271 DOI: 10.1016/j.scitotenv.2020.140652] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 06/29/2020] [Accepted: 06/29/2020] [Indexed: 06/11/2023]
Abstract
Due to their wide-distribution, high-biocompatibility and low-cost, nature-derived quinone redox mediators (NDQRM) have shown great potential in bioremediation through mediating electron transfers between microorganisms and between microorganisms and contaminants in anaerobic biotransformation processes. It is obvious that their performance in bioremediation was limited by the availability of quinone-based groups in NDQRM. A sustainable solution is to enhance the electron transfer capacity and retention capacity by the modification of NDQRM. Therefore, this review comprehensively summarized the modification techniques of NDQRM according to their multiple roles in anaerobic biotransformation systems. In addition, their potential applications in greenhouse gas mitigation, contaminant degradation in anaerobic digestion, contaminant bioelectrochemical remediation and energy recovery were discussed. And the problems that need to be addressed in the future were pointed out. The obtained knowledge would promote the exploration of novel NDQRM, and provide suggestions for the design of anaerobic consortia in biotransformation systems.
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Affiliation(s)
- Yu Zhang
- State Key Laboratory of Pollution Control and Resources Reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China
| | - Zhengzhe Zhang
- State Key Laboratory of Pollution Control and Resources Reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China
| | - Weiguo Liu
- College of Resources and Environment Science, Key Laboratory of Oasis Ecology, Ministry of Education, Xinjiang University, Urumqi 830046, China
| | - Yinguang Chen
- State Key Laboratory of Pollution Control and Resources Reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China.
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21
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Yang B, Luo W, Wang X, Yu S, Gan M, Wang J, Liu X, Qiu G. The use of biochar for controlling acid mine drainage through the inhibition of chalcopyrite biodissolution. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 737:139485. [PMID: 32516660 DOI: 10.1016/j.scitotenv.2020.139485] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2020] [Revised: 04/21/2020] [Accepted: 05/14/2020] [Indexed: 06/11/2023]
Abstract
Although chalcopyrite biodissolution plays an important role in the formation of acid mine drainage (AMD), the control of AMD through inhibiting the biodissolution of chalcopyrite has not been studied until now. In order to fill this knowledge gap, a novel method for inhibiting chalcopyrite biodissolution using biochar was proposed and verified. The effects of biochar pyrolysis temperature and biochar concentration on the inhibition of chalcopyrite biodissolution in the presence of Acidithiobacillus ferrooxidans (A. ferrooxidans) were studied. The results indicate that biochar significantly inhibited chalcopyrite biodissolution, thus reducing the number of copper and iron ions and quantity of acid released. In turn, this suggests that AMD generation was suppressed under these conditions. Biochar pyrolyzed at 300 °C (Biochar-300 °C) was the most effective at inhibiting chalcopyrite biodissolution and reduced its biodissolution rate by 17.7%. A suitable concentration of biochar-300 °C enhanced its inhibition of chalcopyrite biodissolution. The optimal concentration of biochar-300 °C for inhibiting chalcopyrite biodissolution was 3 g/L. Biodissolution results, cyclic voltammetry, mineral surface morphology, mineralogical phase, and elemental composition analyses reveal that biochar inhibited the biodissolution of chalcopyrite by promoting the formation of passivation layer (jarosite and Sn2-/S0) and adsorbing bacteria.
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Affiliation(s)
- Baojun Yang
- School of Minerals Processing and Bioengineering, Central South University, Changsha, China; Key Laboratory of Biohydrometallurgy, Ministry of Education, Changsha, China
| | - Wen Luo
- Department of Dermatology, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Xingxing Wang
- School of Minerals Processing and Bioengineering, Central South University, Changsha, China; Key Laboratory of Biohydrometallurgy, Ministry of Education, Changsha, China
| | - Shichao Yu
- School of Minerals Processing and Bioengineering, Central South University, Changsha, China; Key Laboratory of Biohydrometallurgy, Ministry of Education, Changsha, China
| | - Min Gan
- School of Minerals Processing and Bioengineering, Central South University, Changsha, China; Key Laboratory of Biohydrometallurgy, Ministry of Education, Changsha, China
| | - Jun Wang
- School of Minerals Processing and Bioengineering, Central South University, Changsha, China; Key Laboratory of Biohydrometallurgy, Ministry of Education, Changsha, China.
| | - Xueduan Liu
- School of Minerals Processing and Bioengineering, Central South University, Changsha, China; Key Laboratory of Biohydrometallurgy, Ministry of Education, Changsha, China
| | - Guanzhou Qiu
- School of Minerals Processing and Bioengineering, Central South University, Changsha, China; Key Laboratory of Biohydrometallurgy, Ministry of Education, Changsha, China
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