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Sun P, Mao H, Fang C, Long Y. Effect of hydraulic parameters of leachate treatment process on di(2-ethylhexyl) phthalate removal from aged leachate. ENVIRONMENTAL TECHNOLOGY 2023; 44:2407-2416. [PMID: 35029135 DOI: 10.1080/09593330.2022.2029951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Accepted: 01/08/2022] [Indexed: 06/08/2023]
Abstract
The effect of hydraulic parameters of an anaerobic/anoxic/oxic leachate treatment reactor on the removal of di(2-ethylhexyl) phthalate (DEHP) from aged landfill leachate was studied. The mean DEHP removal efficiencies were 79.5%, 87.1%, 89.7% and 87.8% at hydraulic retention times of 6, 4.5, 3 and 2 d, respectively. The removal efficiency of DEHP was significantly higher when the internal reflux ratio was 200% than others. There was no significant difference among the DEHP removal efficiencies at different external reflux ratios of the reactor. Due to the overall efficiency of the reactor, hydraulic retention time 3 d, internal reflux ratio 200% and external reflux ratio 60%, were considered the optimal hydraulic parameters for DEHP removal from aged leachate. The removal efficiency of DEHP was significantly improved (from 75.7% to 89.1%) after the optimization of hydraulic parameters of the reactor. The removal percentages of DEHP in the anaerobic, anoxic, and oxic units of the reactor were 42.8%, 17.6%, and 15.3%, respectively. The oxic microcosms in the reactor had little effect on DEHP removal. The correlation between DEHP and leachate pollutants indicated that DEHP removal was strongly correlated with leachate COD and NH4+-N.
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Affiliation(s)
- Pingping Sun
- College of Civil Engineering and Architecture, Zhejiang University of Water Resources and Electric Power, Hangzhou, People's Republic of China
| | - Hongzhi Mao
- School of Civil Engineering and Architecture, Zhejiang University of Science and Technology, Hangzhou, People's Republic of China
| | - Chengran Fang
- School of Civil Engineering and Architecture, Zhejiang University of Science and Technology, Hangzhou, People's Republic of China
- College of Civil Engineering, Zhejiang University of Technology, Hangzhou, People's Republic of China
| | - Yuyang Long
- Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling, Zhejiang Gongshang University, Hangzhou, People's Republic of China
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Horn EJ, van Hille RP, Oyekola OO, Welz PJ. Functional Microbial Communities in Hybrid Linear Flow Channel Reactors for Desulfurization of Tannery Effluent. Microorganisms 2022; 10:2305. [PMID: 36422375 PMCID: PMC9695182 DOI: 10.3390/microorganisms10112305] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/19/2024] Open
Abstract
Recent research has demonstrated that hybrid linear flow channel reactors (HLFCRs) can desulfurize tannery effluent via sulfate reduction and concurrent oxidation of sulfide to elemental sulfur. The reactors can be used to pre-treat tannery effluent to improve the efficiency of downstream anaerobic digestion and recover sulfur. This study was conducted to gain insight into the bacterial communities in HLFCRs operated in series and identify structure-function relationships. This was accomplished by interpreting the results obtained from amplicon sequencing of the 16S rRNA gene and quantification of the dissimilatory sulfite reducing (dsrB) gene. In an effort to provide a suitable inoculum, microbial consortia were harvested from saline estuaries and enriched. However, it was found that bioaugmentation was not necessary because native communities from tannery wastewater were selected over exogenous communities from the enriched consortia. Overall, Dethiosulfovibrio sp. and Petrimonas sp. were strongly selected (maximum relative abundances of 29% and 26%, respectively), while Desulfobacterium autotrophicum (57%), and Desulfobacter halotolerans (27%) dominated the sulfate reducing bacteria. The presence of elemental sulfur reducing genera such as Dethiosulfovibrio and Petrimonas is not desirable in HLFCRs, and strategies to counter their selection need to be considered to ensure efficiency of these systems for pre-treatment of tannery effluent.
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Marais TS, Huddy RJ, Harrison STL. Elemental sulphur recovery from a sulphate-rich aqueous stream in a single hybrid linear flow channel reactor is mediated through microbial community dynamics and adaptation to reactor zones. FEMS Microbiol Ecol 2022; 98:6763417. [PMID: 36259757 DOI: 10.1093/femsec/fiac059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Revised: 04/20/2022] [Accepted: 10/03/2022] [Indexed: 01/21/2023] Open
Abstract
The coupled application of biological sulphate reduction (BSR) and partial sulphide oxidation to treat sulphate-rich wastewater is an effective strategy to mitigate pollution and recover elemental sulphur for repurposing. The recent development of the hybrid linear flow channel reactor (LFCR) achieves simultaneous BSR and partial sulphide oxidation with biosulphur recovery via a floating sulphur biofilm (FSB). Here, we explore the microbial community zoning and dynamics facilitating the process. A total of three continuous LFCRs were used to evaluate the effect of reactor zones, hydraulic residence time (HRT), carbon source, namely lactate and acetate, as well as reactor geometry and scale on process performance and microbial community dynamics. Community composition of sessile and planktonic microbial consortia were resolved at a 5- and 2-day HRT through 16S rRNA amplicon sequencing. Preferential attachment and prevalence of specific phylotypes within the sessile and planktonic communities revealed clear adaptation of key microorganisms to different microenvironments. Key microbial taxa affiliated with sulphate reduction and sulphide oxidation as well as those implicated in fermentation and syntrophic metabolism, fluctuated in response to changes in HRT and process performance. Through understanding the relationship between microbial community dynamics and process performance, this research will inform better process design and optimization of the hybrid LFCR.
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Affiliation(s)
- T S Marais
- Centre for Bioprocess Engineering Research, Department of Chemical Engineering, University of Cape Town, Private Bag X1, Rondebosch 7701, South Africa.,Future Water Institute, 1 Madiba Circle, University of Cape Town, 7700, South Africa
| | - R J Huddy
- Centre for Bioprocess Engineering Research, Department of Chemical Engineering, University of Cape Town, Private Bag X1, Rondebosch 7701, South Africa.,Future Water Institute, 1 Madiba Circle, University of Cape Town, 7700, South Africa
| | - S T L Harrison
- Centre for Bioprocess Engineering Research, Department of Chemical Engineering, University of Cape Town, Private Bag X1, Rondebosch 7701, South Africa.,Future Water Institute, 1 Madiba Circle, University of Cape Town, 7700, South Africa
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Marais TS, Huddy RJ, Van Hille RP, Harrison STL. Effect of temperature change on the performance of the hybrid linear flow channel reactor and its implications on sulphate-reducing and sulphide-oxidising microbial community dynamics. Front Bioeng Biotechnol 2022; 10:908463. [PMID: 36091461 PMCID: PMC9458953 DOI: 10.3389/fbioe.2022.908463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 07/21/2022] [Indexed: 11/22/2022] Open
Abstract
Semi-passive bioremediation is a promising strategy to mitigate persistent low volume mine-impacted wastewater containing high sulphate concentrations. Building on the proof of concept demonstration of the hybrid linear flow channel reactor (LFCR), capable of simultaneous biological sulphate reduction and partial sulphide oxidation with elemental sulphur recovery, the impact of key operating parameters, such as temperature, on process performance is critical to real-world application. Temperature fluctuates seasonally and across the diurnal cycle, impacting biological sulphate reduction (BSR) and partial sulphide oxidation. The process is reliant on the metabolic activity and synergistic interactions between sulphate-reducing (SRB) and sulphide-oxidising (SOB) microbial communities that develop within discrete oxic and anoxic microenvironments within the hybrid LFCR. In this study, the impact of operating temperature on process performance was evaluated by decreasing temperature with time from 30 to 10°C in each of three laboratory-scaled hybrid LFCR units operating in pseudo-steady state at 1 g/L sulphate. Using lactate as a carbon source, two reactor sizes (2 and 8 L) were considered, while the impact of lactate vs. acetate as carbon source was evaluated in the 2 L reactors. On incremental decrease in temperature from 30 to 10°C, a decrease in volumetric sulphate reduction rate was observed: from 0.144 to 0.059 mmol/L.h in the 2 L lactate-fed reactor; from 0.128 to 0.042 mmol/L.h in the 8 L lactate-fed reactor; and from 0.127 to 0.010 mmol/L.h in the 2 L acetate-fed reactor. Similarly, sulphate conversion efficiency decreased (2 L lactate-fed: 66% to 27%; 8 L lactate-fed: 61% to 20%; 2 L acetate-fed: 61% to 5%). A decrease in temperature below the critical value (15°C) led to considerable loss in metabolic activity and overall BSR performance. Sessile and planktonic microbial communities were represented by bacterial phyla including Proteobacteria, Synergistetes, Bacteroidetes, and Firmicutes. A diverse group of putative SRB (Deltaproteobacteria) and SOB, including Alpha, Beta, Gamma, and Epsilonproteobacteria phylotypes, were prevalent and shifted in relative abundance and community composition in response to decreasing temperature. Specifically, the decrease in the relative abundance of Deltaproteobacteria with decreasing temperature below 15°C corresponded with a loss of BSR performance across all three reactors. This study demonstrated the impact of low temperature on the physiological selection and ecological differentiation of SRB and SOB communities within the hybrid LFCR and its implications for real-world process performance.
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Affiliation(s)
- T. S. Marais
- Department of Chemical Engineering, Centre for Bioprocess Engineering Research, University of Cape Town, Cape Town, South Africa
| | - R. J. Huddy
- Department of Chemical Engineering, Centre for Bioprocess Engineering Research, University of Cape Town, Cape Town, South Africa
- The Future Water Institute, University of Cape Town, Cape Town, South Africa
| | | | - S. T. L. Harrison
- Department of Chemical Engineering, Centre for Bioprocess Engineering Research, University of Cape Town, Cape Town, South Africa
- The Future Water Institute, University of Cape Town, Cape Town, South Africa
- *Correspondence: S. T. L. Harrison,
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Wang K, Qaisar M, Chen B, Xiao J, Cai J. Metagenomic analysis of microbial community and metabolic pathway of simultaneous sulfide and nitrite removal process exposed to divergent hydraulic retention times. BIORESOURCE TECHNOLOGY 2022; 354:127186. [PMID: 35439563 DOI: 10.1016/j.biortech.2022.127186] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 04/14/2022] [Accepted: 04/15/2022] [Indexed: 06/14/2023]
Abstract
The role of hydraulic retention time (HRT) on S0 production was assessed through metagenomics analyses. Considering comprehensive performance for the tested HRTs (0.25-13.33 h), the optimal HRT was 1 h, while respective sulfide and nitrite loading rate could reach 6.84 kg S/(m3·d) and 1.95 kg N/(m3·d), and total S0 yield was 0.36 kg S/(kg (VSS)·d). Bacterial community richness decreased along the shortening of HRT. Microbacterium, Sulfurimonas, Sulfurovum, Paracoccus and Thauera were highly abundant bacteria. During sulfur metabolism, high expression of sqr gene was the main reason of maintaining high desulfurization load, while lacking soxB caused the continuous increase of S0. Regarding nitrogen metabolism, the rapid decrease of nitrite transporter prevented nitrite to enter in cells, which caused a rapid decrease of nitrite removal under extreme HRT. Adjusting HRT is an effective way to enhance S0 production for the application of the simultaneous sulfide and nitrite removal process.
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Affiliation(s)
- Kaiquan Wang
- College of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, China
| | - Mahmood Qaisar
- Department of Environmental Sciences, COMSATS University Islamabad, Abbottabad Campus, Pakistan; College of Science, University of Bahrain, Bahrain
| | - Bilong Chen
- College of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, China
| | - Jinghong Xiao
- College of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, China
| | - Jing Cai
- College of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, China; International Science and Technology Cooperation Platform for Low-Carbon Recycling of Waste and Green Development, Zhejiang Gongshang University, Hangzhou, China.
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Roesel LK, Zak DH. Treating acid mine drainage with decomposed organic soil: Implications for peatland rewetting. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 311:114808. [PMID: 35245841 DOI: 10.1016/j.jenvman.2022.114808] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 02/16/2022] [Accepted: 02/23/2022] [Indexed: 06/14/2023]
Abstract
Acidification and salinisation of groundwater and surface water bodies are worldwide problems in post-mining landscapes due to acid mine drainage (AMD). In this study, we hypothesised that highly decomposed peat offers a suitable substrate for mitigating AMD pollution of water bodies and that hydraulic load affects the removal efficiency of iron and sulphate. A lysimeter experiment was conducted mimicking peatland rewetting to quantify iron and sulphate removal and pH changes at different loading rates. The low initial pH of 4 rose to 6 and electrical conductivity declined by up to 47%. The initially high concentrations of iron (>250 mg/L) and sulphate (>770 mg/L) declined by, on average, 87 and 78%, respectively. The removal efficiency of sulphate was negatively correlated with either the hydraulic or the sulphate load, respectively, i. e. the lower the hydraulic load, the higher the removal efficiency of sulphate. However, the removal of iron was not explained by the load. The results imply that desulphurication and thus subsequent precipitation of iron sulphides was the main removal process and that peatland rewetting is an effective measure to mitigate AMD pollution of freshwater systems. For the heavily AMD-polluted studied section of the River Spree, we estimated by combining experimental with field data that a sulphate load reduction of the river by about 20% (36,827 tons/yr) will occur if all peatlands in the sub-catchment (6067 ha; 6.7% of the total area) are rewetted. Future investigations must show if the pollutant removal is declining over time in decomposed peat layers due to acidification and/or lack of bioavailable carbon and how the rewetting of peatland with AMD will affect the restoration of their ecosystem functioning in the long term.
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Affiliation(s)
- Lydia K Roesel
- Humboldt University of Berlin, Germany; FIB - Research Institute for Post-Mining Landscapes, Finsterwalde, Germany.
| | - Dominik H Zak
- Department of Ecoscience, Aarhus University, Denmark; Department of Ecohydrology and Biogeochemistry, Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Germany.
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Liu H, Li H, Fang C, Mao H, Xue X, Wang Q. Removal of Di-n-butyl phthalate from aged leachate under optimal hydraulic condition of leachate treatment process and in the presence of its dominant bacterial strains. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2021; 222:112532. [PMID: 34280839 DOI: 10.1016/j.ecoenv.2021.112532] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 07/13/2021] [Accepted: 07/14/2021] [Indexed: 06/13/2023]
Abstract
The effects of hydraulic condition of reactor and the dominant degrading bacteria on the removal of di-n-butyl phthalate (DBP) from aged landfill leachate by anaerobic/anoxic/oxic (A/A/O) leachate treatment process were investigated. The optimal DBP removal (96.0%) was obtained from aged leachate when the hydraulic retention time (HRT) of the reactor was 3 d, internal reflux ratio of the reactor was 200%, and external reflux ratio of the reactor was 60%, respectively. The removal efficiency of DBP was significantly improved after the inoculation of the dominant DBP-degrading bacteria (Pseudomonas sp. W1) in the reactor. The mean removal efficiencies of DBP before and after inoculation were 94.1% and 97.7%, respectively. Furthermore, the inoculation of dominant DBP-degrading bacteria changed the original sludge structure and characteristics, which was more conducive to the removal of DBP. These results provide theoretical basis for the effective removal of DBP from aged leachate by the biological treatment process.
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Affiliation(s)
- Hongyuan Liu
- College of Civil Engineering, Zhejiang University of Technology, Hangzhou 310023, China
| | - Hong Li
- College of Civil Engineering, Zhejiang University of Technology, Hangzhou 310023, China
| | - Chengran Fang
- College of Civil Engineering, Zhejiang University of Technology, Hangzhou 310023, China; Key Laboratory of Recycling and Eco-treatment of Waste Biomass of Zhejiang Province, Zhejiang University of Science and Technology, Hangzhou 310023, China.
| | - Hongzhi Mao
- Key Laboratory of Recycling and Eco-treatment of Waste Biomass of Zhejiang Province, Zhejiang University of Science and Technology, Hangzhou 310023, China
| | - Xiangdong Xue
- Key Laboratory of Recycling and Eco-treatment of Waste Biomass of Zhejiang Province, Zhejiang University of Science and Technology, Hangzhou 310023, China
| | - Qun Wang
- Key Laboratory of Recycling and Eco-treatment of Waste Biomass of Zhejiang Province, Zhejiang University of Science and Technology, Hangzhou 310023, China
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