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Xu R, Zhang Z, Deng C, Nie C, Wang L, Shi W, Lyu T, Yang Q. Micropollutant rejection by nanofiltration membranes: A mini review dedicated to the critical factors and modelling prediction. ENVIRONMENTAL RESEARCH 2024; 244:117935. [PMID: 38103781 DOI: 10.1016/j.envres.2023.117935] [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: 10/25/2023] [Revised: 11/22/2023] [Accepted: 12/11/2023] [Indexed: 12/19/2023]
Abstract
Nanofiltration (NF) membranes, extensively used in advanced wastewater treatment, have broad application prospects for the removal of emerging trace organic micropollutants (MPs). The treatment performance is affected by several factors, such as the properties of NF membranes, characteristics of target MPs, and operating conditions of the NF system concerning MP rejection. However, quantitative studies on different contributors in this context are limited. To fill the knowledge gap, this study aims to assess critical impact factors controlling MP rejection and develop a feasible model for MP removal prediction. The mini-review firstly summarized membrane pore size, membrane zeta potential, and the normalized molecular size (λ = rs/rp), showeing better individual relationships with MP rejection by NF membranes. The Lindeman-Merenda-Gold model was used to quantitatively assess the relative importance of all summarized impact factors. The results showed that membrane pore size and operating pressure were the high impact factors with the highest relative contribution rates to MP rejection of 32.11% and 25.57%, respectively. Moderate impact factors included membrane zeta potential, solution pH, and molecular radius with relative contribution rates of 10.15%, 8.17%, and 7.83%, respectively. The remaining low impact factors, including MP charge, molecular weight, logKow, pKa and crossflow rate, comprised all the remaining contribution rates of 16.19% through the model calculation. Furthermore, based on the results and data availabilities from references, the machine learning-based random forest regression model was trained with a relatively low root mean squared error and mean absolute error of 12.22% and 6.92%, respectively. The developed model was then successfully applied to predict MPs' rejections by NF membranes. These findings provide valuable insights that can be applied in the future to optimize NF membrane designs, operation, and prediction in terms of removing micropollutants.
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Affiliation(s)
- Rui Xu
- Chinese Research Academy of Environmental Sciences, Beijing, 100012, China; National Joint Research Center for Yangtze River Conservation, Beijing, 100012, China
| | - Zeqian Zhang
- Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
| | - Chenning Deng
- Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
| | - Chong Nie
- Chinese Research Academy of Environmental Sciences, Beijing, 100012, China; National Joint Research Center for Yangtze River Conservation, Beijing, 100012, China
| | - Lijing Wang
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Wenqing Shi
- School of Environmental Science & Engineering, Nanjing University of Information Science & Technology, Nanjing, 210044, China
| | - Tao Lyu
- School of Water, Energy and Environment, Cranfield University, College Road, Cranfield, Bedfordshire, MK43 0AL, United Kingdom.
| | - Queping Yang
- Chinese Research Academy of Environmental Sciences, Beijing, 100012, China; National Joint Research Center for Yangtze River Conservation, Beijing, 100012, China.
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2
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Song N, Zhang Q, Wang Y, Gao L, Liu S, Yao H, Liu R, Xu H. Investigation on molecular characteristics of organic compounds during a full-scale landfill leachate treatment process based on non-targeted analysis. ENVIRONMENTAL RESEARCH 2023; 238:117258. [PMID: 37775003 DOI: 10.1016/j.envres.2023.117258] [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: 07/28/2023] [Revised: 09/17/2023] [Accepted: 09/27/2023] [Indexed: 10/01/2023]
Abstract
In this study, a new methodology for evaluating full-scale landfill leachate treatment processes by non-targeted analysis using comprehensive two-dimensional gas chromatography quadrupole time-of-flight mass spectrometry (GC × GC-QTOF-MS) was proposed. The method revealed the chemical complexity of organic compounds in landfill leachate samples at the molecular level and evaluated the removal efficiency of the anaerobic-anoxic-oxic (A2O) - membrane bioreactor (MBR) - nanofiltration (NF) treatment process in conjunction with multi-level classification of organic compounds. Results showed that the results of non-targeted analysis combined with multi-level classification of organic compounds had a significant correlation with the conventional water quality parameters and can be used to evaluate the treatment process. A total of 2508 organic compounds were detected in 6 samples. 17 emerging contaminants (ECs) with known potentially hazards were detected, including Diisobutyl Phthalate (DIBP), which is toxic to male reproduction and development, and 4-Tert-Butylphenol, which causes endocrine disruption in animals. The removal rate of organic compounds by this full-scale landfill leachate treatment processes reached 79.14%. The anaerobic tank played a crucial role with 64.98% contribution. For compounds, the removal rate of heterocyclics was as high as 94.67%, and the removal rate of aliphatics was poor, only 63.49%. This treatment process had almost perfect removal effect on the steroids in alicyclics and phenols in aromatics, but poor treatment effect on saturated alkanes in aliphatics and naphthenes in alicyclics. This study provides a methodology for accurate assessment of the molecular level of treatment processes, new insights for process optimization in waste treatment plants, and data support for the detection of emerging contaminants. The environmental hazards of landfill leachate can be further evaluated in the future in conjunction with ecotoxicity assessment studies.
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Affiliation(s)
- Ninghui Song
- Nanjing Institute of Environmental Sciences, Ministry of Ecology and Environment, Nanjing, 210042, PR China
| | - Qian Zhang
- Nanjing Institute of Environmental Sciences, Ministry of Ecology and Environment, Nanjing, 210042, PR China; College of Environment, Hohai University, Nanjing, 210098, PR China
| | - Yixuan Wang
- Nanjing Institute of Environmental Sciences, Ministry of Ecology and Environment, Nanjing, 210042, PR China
| | - Li Gao
- Nanjing Institute of Environmental Sciences, Ministry of Ecology and Environment, Nanjing, 210042, PR China
| | - Sitao Liu
- Department of Chemical and Environmental Engineering, University of California, Riverside, CA, 92521, USA
| | - Hao Yao
- Zhenjiang New Area Ecology and Environment and Emergency Management Bureau, Zhenjiang, 212132, PR China
| | - Ru Liu
- Nanjing Institute of Environmental Sciences, Ministry of Ecology and Environment, Nanjing, 210042, PR China
| | - Hang Xu
- College of Environment, Hohai University, Nanjing, 210098, PR China; Suzhou Research Institute, Hohai University, Suzhou, 215100, PR China.
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3
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El-Saadony MT, Saad AM, El-Wafai NA, Abou-Aly HE, Salem HM, Soliman SM, Abd El-Mageed TA, Elrys AS, Selim S, Abd El-Hack ME, Kappachery S, El-Tarabily KA, AbuQamar SF. Hazardous wastes and management strategies of landfill leachates: A comprehensive review. ENVIRONMENTAL TECHNOLOGY & INNOVATION 2023; 31:103150. [DOI: 10.1016/j.eti.2023.103150] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
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4
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de Almeida R, Porto RF, Quintaes BR, Bila DM, Lavagnolo MC, Campos JC. A review on membrane concentrate management from landfill leachate treatment plants: The relevance of resource recovery to close the leachate treatment loop. WASTE MANAGEMENT & RESEARCH : THE JOURNAL OF THE INTERNATIONAL SOLID WASTES AND PUBLIC CLEANSING ASSOCIATION, ISWA 2023; 41:264-284. [PMID: 35924944 PMCID: PMC9972246 DOI: 10.1177/0734242x221116212] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 05/25/2022] [Indexed: 05/19/2023]
Abstract
Membrane filtration processes have been used to treat landfill leachate. On the other hand, closing the leachate treatment loop and finding a final destination for landfill leachate membrane concentrate (LLMC) - residual stream of membrane systems - is challenging for landfill operators. The re-introduction of LLMC into the landfill is typical; however, this approach is critical as concentrate pollutants may accumulate in the leachate treatment facility. From that, leachate concentrate management based on resource recovery rather than conventional treatment and disposal is recommended. This work comprehensively reviews the state-of-the-art of current research on LLMC management from leachate treatment plants towards a resource recovery approach. A general recovery train based on the main LLMC characteristics for implementing the best recovery scheme is presented in this context. LLMCs could be handled by producing clean water and add-value materials. This paper offers critical insights into LLMC management and highlights future research trends.
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Affiliation(s)
- Ronei de Almeida
- School of Chemistry, Inorganic
Processes Department, Universidade Federal do Rio de Janeiro, Rio de Janeiro,
Brazil
- Department of Civil, Environmental and
Architectural Engineering, University of Padova, Padova, Italy
- Ronei de Almeida, School of Chemistry,
Inorganic Processes Department, Universidade Federal do Rio de Janeiro, 149
Athos da Silveira Ramos Avenue, laboratory I-124, Rio de Janeiro, RJ 21941-909,
Brazil.
| | - Raphael Ferreira Porto
- School of Chemistry, Inorganic
Processes Department, Universidade Federal do Rio de Janeiro, Rio de Janeiro,
Brazil
| | | | - Daniele Maia Bila
- Department of Sanitary and Environment
Engineering, State University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Maria Cristina Lavagnolo
- Department of Civil, Environmental and
Architectural Engineering, University of Padova, Padova, Italy
| | - Juacyara Carbonelli Campos
- School of Chemistry, Inorganic
Processes Department, Universidade Federal do Rio de Janeiro, Rio de Janeiro,
Brazil
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5
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Huang Y. Degradation of refractory organic matter in the effluent from a semi-aerobic aged refuse biofilter-treated landfill leachate by a nano-Fe 3O 4 enhanced ozonation process. WASTE MANAGEMENT & RESEARCH : THE JOURNAL OF THE INTERNATIONAL SOLID WASTES AND PUBLIC CLEANSING ASSOCIATION, ISWA 2022; 40:1242-1255. [PMID: 34967246 DOI: 10.1177/0734242x211066229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
In this study, the transformation and degradation mechanisms of refractory organic matter in biologically treated leachate from a semi-aerobic aged refuse biofilter (SAARB) in a nano-Fe3O4 enhanced ozonation process (nFe3O4-O3) were investigated in batch experiments. A continuous experiment then confirmed the effectiveness of the process for SAARB effluent treatment. In a batch experiment, the effects of influencing factors, including nFe3O4 dosage, O3 dosage and initial pH on the treatment performance of nFe3O4-O3 process, were comprehensively investigated. The results showed that when the nFe3O4 dosage = 6 g L-1, O3 dosage = 0.15 L minute-1 and initial pH = 7, the total organic carbon, absorbance at 254 nm and colour number removal efficiencies were 40.58%, 62.55% and 89.80%, respectively. In addition, most of the humic- and fulvic-like substances in the SAARB effluent were removed, and the condensation degree, aromaticity and humification degree of the organics were substantially reduced. The morphology and elemental valence state analysis showed that the nFe3O4 in the process was relatively stable and could form an nFe3O4-organic complex. Therefore, the probability of organics reacting with hydroxyl radical increased and the oxidation efficiency was enhanced. In the continuous experiment, both the O3 dosage and hydraulic retention time (HRT) were the key influencing factors. The treatment efficiency of the nFe3O4-O3 process was enhanced at a higher O3 dosage and longer HRT. The electrical energy consumption of the continuous nFe3O3-O3 process was calculated to be 17.72 kW h m-3 in SAARB effluent treatment. This study proved the feasibility of biologically treated landfill leachate treatment by the nFe3O3-O3 process.
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Affiliation(s)
- Yuyu Huang
- Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, China
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6
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de Almeida R, Pimenta de Oliveira TJ, Maurício Gouvea R, Carbonelli Campos J. Technical and economic aspects of a sequential MF + NF + zeolite system treating landfill leachate. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART A, TOXIC/HAZARDOUS SUBSTANCES & ENVIRONMENTAL ENGINEERING 2022; 57:675-684. [PMID: 35876049 DOI: 10.1080/10934529.2022.2101842] [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: 03/07/2022] [Revised: 06/30/2022] [Accepted: 07/07/2022] [Indexed: 06/15/2023]
Abstract
This work explores the techno-economic aspects of landfill leachate treatment by an integrated scheme composed of microfiltration (MF), nanofiltration (NF), and zeolite application for carbon and nitrogen removal. In bench-scale experiments, MF and NF were investigated, and zeolite batch tests were carried out to determine optimum conditions. A preliminary economic analysis is presented for a 200 m3 d-1 full-scale treatment facility based on the data obtained from experimental tests and literature surveys. The maximum removals of 92%, 94%, and 79% for chemical oxygen demand (COD), absorbance at 254 nm, and ammonium nitrogen (NH4+-N) were achieved in bench experiments, respectively. It was possible to reach the local discharge standard for COD (200 mg L-1), but it was not possible to reach the Brazilian disposal requirement for NH4+-N (20 mg L-1). The total cost of the integrated MF + NF + zeolite system was estimated at 19.89 US$m-3. In this study, the costs of the zeolite application account for around 70% of the total costs of the integrated scheme. Membrane process integration was an adequate strategy for removing organic compounds at low operating costs; However, further NH4+-N depuration is needed to meet discharge requirements.
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Affiliation(s)
- Ronei de Almeida
- School of Chemistry, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
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7
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Gasmi A, Ibrahimi S, Elboughdiri N, Tekaya MA, Ghernaout D, Hannachi A, Mesloub A, Ayadi B, Kolsi L. Comparative Study of Chemical Coagulation and Electrocoagulation for the Treatment of Real Textile Wastewater: Optimization and Operating Cost Estimation. ACS OMEGA 2022; 7:22456-22476. [PMID: 35811923 PMCID: PMC9260942 DOI: 10.1021/acsomega.2c01652] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Accepted: 06/03/2022] [Indexed: 05/23/2023]
Abstract
Pollutants derived from real textile wastewater present a high environmental risk. This work involves the study of the removal of chemical oxygen demand (COD), color, and turbidity from Tunisian real textile wastewater by two different water treatment technologies: chemical coagulation (CC) and electrocoagulation (EC). A comparative study between these two methods was conducted based on the separation performance and operating cost (OC). The effects of different operational parameters including electrolysis time (t), voltage, and pH for EC and the coagulant concentration, initial pH, and time of slow mixing (t sm) for CC were studied using response surface methodology. The developed quadratic models for the responses were in good agreement with the experimental data. The experiments proved the efficiency of both chemical and electrochemical techniques for the treatment of textile effluent. Indeed, by using EC, the reduction efficiencies of COD, color, and turbidity were 63.05, 99.07, and 96.31%, respectively, under optimal conditions (pH 9, t = 36.26 min, and voltage 4 V). For CC treatment, the achieved removal efficiencies of COD, color, and turbidity were 54.02, 96.21, and 93.7%, respectively, at pH 8.57, a coagulant concentration of 204.75 mg/L, and a t sm of 28.41 min as optimal operating conditions. The OC obtained for EC and CC was about 0.47 and 0.2 USD/m3, respectively. Even if the OC of the EC process was higher as compared to the CC process, the treated water obtained by EC meets the Tunisian Standards (NT 106.03 and NT 09-14) for textile wastewater discharge into the environment and demonstrates a high potential for its reuse in various industrial activities. EC technology can be integrated into a wastewater management system that ensures a zero liquid discharge of wastewater into the environment.
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Affiliation(s)
- Aicha Gasmi
- Laboratory
of Engineering Processes and Industrial Systems, Chemical Engineering
Department, National School of Engineers of Gabes, University of Gabes, Street Omar Ibn El-Khattab, Gabes 6029, Tunisia
| | - Soumaya Ibrahimi
- Mechanical
Modeling, Energy and Materials Unit Research (MEM), National School of Engineering of Gabes, Gabes 6029, Tunisia
| | - Noureddine Elboughdiri
- Chemical
Engineering Department, College of Engineering, University of Ha′il, P.O. Box
2440, Ha′il 81441, Saudi Arabia
- Chemical
Engineering Process Department, National School of Engineers Gabes, University of Gabes, Gabes 6029, Tunisia
| | - Mohamed Aymen Tekaya
- Laboratory
of Engineering Processes and Industrial Systems, Chemical Engineering
Department, National School of Engineers of Gabes, University of Gabes, Street Omar Ibn El-Khattab, Gabes 6029, Tunisia
| | - Djamel Ghernaout
- Chemical
Engineering Department, College of Engineering, University of Ha′il, P.O. Box
2440, Ha′il 81441, Saudi Arabia
- Chemical
Engineering Department, Faculty of Engineering, University of Blida, P.O. Box 270, Blida 09000, Algeria
| | - Ahmed Hannachi
- Laboratory
of Engineering Processes and Industrial Systems, Chemical Engineering
Department, National School of Engineers of Gabes, University of Gabes, Street Omar Ibn El-Khattab, Gabes 6029, Tunisia
| | - Abdelhakim Mesloub
- Department
of Architectural Engineering, College of Engineering, University of Ha′il, P.O. Box
2440, Ha′il 81441, Saudi Arabia
| | - Badreddine Ayadi
- Department
of Mechanical Engineering, College of Engineering, University of Ha′il, P.O. Box
2440, Ha′il 81441, Saudi Arabia
| | - Lioua Kolsi
- Department
of Mechanical Engineering, College of Engineering, University of Ha′il, P.O. Box
2440, Ha′il 81441, Saudi Arabia
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8
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Costa AM, Dos Santos Valentim MR, da Silva LF, de Almeida R, Daflon SDA, Quintaes BR, Campos JC. Comparison between Aliivibrio fischeri and activated sludge microorganisms in the evaluation of the toxic pollutants of leachates from Brazilian landfills. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:1546-1558. [PMID: 34351579 DOI: 10.1007/s11356-021-15771-9] [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: 01/19/2021] [Accepted: 07/28/2021] [Indexed: 06/13/2023]
Abstract
Ecotoxicological assessment of landfill leachate has become a priority to determine its impacts on the ecosystem. Toxicity assays with microorganisms stand out due to their quick response, low cost and ease of testing. In this context, the present study evaluated the acute toxic effects of leachates from two landfills of different ages and modes of operation to bacterium Aliivibrio fischeri and activated sludge microorganisms and the ammonia nitrogen and humic substances (HS) sensitivity to these organisms. Reductions greater than 30% in leachate toxicity were observed after ammonia removal for A. fischeri and activated sludge microorganisms. After 97% removal of HS, the greater reductions in toxicity (44.28 to 79.82%) were verified for microbial species studied, indicating that the organic compounds (measured as chemical oxygen demand, total organic carbon and humic substances) were the primary pollutants responsible for the toxicity of the leachates. Concerning the organisms studied, A. fischeri showed greater sensitivity to the leachates' pollutants compared to the activated sludge microorganisms. Nevertheless, a strong correlation was observed between A. fischeri and activated sludge microorganisms' toxicity responses, suggesting that respirometry assay can be used to determine leachate toxicity.
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Affiliation(s)
- Alyne Moraes Costa
- School of Chemistry, Federal University of Rio de Janeiro, Athos da Silveira Ramos Avenue 149, Rio de Janeiro, 21941-909, Brazil
| | | | - Livia Ferreira da Silva
- School of Chemistry, Federal University of Rio de Janeiro, Athos da Silveira Ramos Avenue 149, Rio de Janeiro, 21941-909, Brazil
| | - Ronei de Almeida
- School of Chemistry, Federal University of Rio de Janeiro, Athos da Silveira Ramos Avenue 149, Rio de Janeiro, 21941-909, Brazil
| | - Sarah Dario Alves Daflon
- School of Chemistry, Federal University of Rio de Janeiro, Athos da Silveira Ramos Avenue 149, Rio de Janeiro, 21941-909, Brazil
| | - Bianca Ramalho Quintaes
- Municipal Company of Urban Cleaning of Rio de Janeiro, Américo de Souza Braga street 647, Rio de Janeiro, 22783-385, Brazil
| | - Juacyara Carbonelli Campos
- School of Chemistry, Federal University of Rio de Janeiro, Athos da Silveira Ramos Avenue 149, Rio de Janeiro, 21941-909, Brazil.
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9
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Ahmed Z, Yusoff MS, Kamal NHM, Aziz HA. Optimization of the humic acid separation and coagulation with natural starch by RSM for the removal of COD and colour from stabilized leachate. WASTE MANAGEMENT & RESEARCH : THE JOURNAL OF THE INTERNATIONAL SOLID WASTES AND PUBLIC CLEANSING ASSOCIATION, ISWA 2021; 39:1396-1405. [PMID: 33928820 DOI: 10.1177/0734242x211012775] [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] [Indexed: 06/12/2023]
Abstract
The removal of concentrated colour (around 5039 Pt-Co) and chemical oxygen demand (COD; around 4142 mg L-1) from matured landfill leachate through a novel combination of humic acid extraction and coagulation with natural oil palm trunk starch (OPTS) was investigated in this study. Central composite design from response surface methodology of Design Expert-10 software executed the experimental design to correlate experimental factors with desired responses. Analysis of variance developed the quadratic model for four factors (e.g. coagulant dosage, slow mixing speed and time and centrifugation duration) and two responses (% removal of colour, COD). The model confirmed the highest colour (84.96%) and COD (48.84%) removal with a desirability function of 0.836 at the optimum condition of 1.68 g L-1 coagulant dose, 19.11 rpm slow mixing speed, 16.43 minutes for mixing time and 35.75 minutes for centrifugation duration. Better results of correlation coefficient (R2 = 0.98 and 0.96) and predicted R2 (0.94 and 0.84) indicates the model significance. Electron microscopic images display the amalgamation of flocs through bridging. Fourier transforms infrared spectra confirmed the existence of selected organic groups in OPTS, which eventually signifies the applied method.
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Affiliation(s)
- Zaber Ahmed
- School of Civil Engineering, Universiti Sains Malaysia, Nibong Tebal, Penang, Malaysia
| | - Mohd Suffian Yusoff
- School of Civil Engineering, Universiti Sains Malaysia, Nibong Tebal, Penang, Malaysia
| | | | - Hamidi Abdul Aziz
- School of Civil Engineering, Universiti Sains Malaysia, Nibong Tebal, Penang, Malaysia
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10
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Babaei S, Sabour MR, Moftakhari Anasori Movahed S. Combined landfill leachate treatment methods: an overview. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:59594-59607. [PMID: 34510344 DOI: 10.1007/s11356-021-16358-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Accepted: 09/01/2021] [Indexed: 06/13/2023]
Abstract
Landfill leachate is commonly heavily contaminated and consists of high amount of organic compounds, inorganic salts, toxic gases, halogenated hydrocarbons, and heavy metals that exerts a serious threat to public health and the environment. Thus, it requires treatments before direct release into receiving waters. Selecting the efficient method for leachate treatment is still a major challenge. While physicochemical treatment methods such as coagulation-flocculation, adsorption, membrane filtration, ozonation, air stripping, and advanced oxidation processes (AOP) are appropriate for mature leachate, young leachate requires biological treatments including membrane bioreactor (MBR), activated sludge (AS), upflow anaerobic sludge blanket (UASB), and rotational biological contactor (RBC). Recently, the integration of biological processes and physicochemical methods has been demonstrated to be very efficient. It is found that combined coagulation-flocculation/nanofiltration and activated sludge/reverse osmosis are more efficacious than other integrated physicochemical methods and combined physicochemical/biological methods, respectively.
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Affiliation(s)
- Shamimeh Babaei
- Faculty of Civil Engineering, K. N. Toosi University of Technology, Tehran, Iran
| | - Mohammad Reza Sabour
- Faculty of Civil Engineering, K. N. Toosi University of Technology, Tehran, Iran
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11
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Ghaffariraad M, Ghanbarzadeh Lak M. Landfill Leachate Treatment Through Coagulation-flocculation with Lime and Bio-sorption by Walnut-shell. ENVIRONMENTAL MANAGEMENT 2021; 68:226-239. [PMID: 34100132 DOI: 10.1007/s00267-021-01489-4] [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: 02/11/2021] [Accepted: 05/25/2021] [Indexed: 06/12/2023]
Abstract
Due to the environmental consequences corresponding to leachate penetration, a sequence of inexpensive conventional processes proposed leachate treatment. The main objective was maximizing the COD and heavy metal removal efficiencies while minimizing generated sludge volume and material consumption rate. Walnut-shell adsorption complements lime treatment by eliminating heavy metals and low molecular-weight organic compounds. Samples gathered from Nazlou-landfill, Urmia, Iran. The relative significance of independent variables (lime and walnut-shell dosages and pH) on the removal efficiency was investigated using response surface methodology. By estimating the gradient of relative equations of the experimental results, the ideal direction of independent variable change was found as such increasing COD removal. A new variable called OSVLDR was utilized for measuring the ratio of the observed sludge volume to used lime dosage. The proposed sequence resulted in 43.24% COD removal under optimal conditions (i.e., 6.83, and 25 g/L of lime and walnut-shell dosage and pH values of 6, and 4 for two sets). Furthermore, effective removal in heavy metal concentrations was observed, i.e., 98.17, 67.45, 91.03, and 88.02% for nickel, cadmium, zinc, and lead, respectively. The results showed that a change in variables' amount affects associated costs while making a variation at removal efficiency. Reducing the initial pH value of leachate to 3.50 might decrease the consumed raw materials and OSVLDR value, resulting in a considerable decline in material costs (by 10%). Also, the inactive walnut-shell surface with a more crushing degree was used to reduce costs in walnut-shell set experiments rather than the activated surface.
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Affiliation(s)
- Milad Ghaffariraad
- Environmental Engineering, School of Engineering, Civil Engineering Department, Urmia University, Urmia, Iran
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