High-rate anaerobic decolorization of methyl orange from synthetic azo dye wastewater in a methane-based hollow fiber membrane bioreactor
Graphical abstract
Introduction
Azo dyes containing aromatic groups and one or more NN group, represent the largest class of dyes applied in the textile industry (dos Santos et al., 2007; Goncalves et al., 2009). However, approximately 8–20 % of the azo dyes are eventually discharged to the textile effluent due to their incomplete utilization (Chhabra et al., 2015; Wang et al., 2018), which causes high toxicity and mutagenicity in aquatic life and humans (Bras et al., 2005; Mahmood et al., 2016). Although a series of physiochemical methods for treating textile wastewater are technically feasible, they are costly (Fontenot et al., 2003). In contrast, due to its low cost and environmental friendliness, the biological treatment approach, especially anaerobic biological techniques, is a promising strategy for decolorization of textile wastewater (Georgiou and Aivasidis, 2006; Kim et al., 2008). Conventional anaerobic biological techniques, such as upflow anaerobic sludge blanket (UASB) (Bras et al., 2005), fluidized-bed loop reactor (FBLR) (Georgiou and Aivasidis, 2006) and sequencing batch reactor (SBR) (Yu et al., 2015; Yemashova et al., 2004), have been successfully used for the reductive decolorization of azo dyes. However, all these biological approaches consume large amounts of external organic carbon, such as glucose and acetate. The achievement of complete dyes decolorization and simultaneous minimization of energy and organic carbon consumption is the key breakthrough for biological treatment of textile wastewater.
Methane is a significant greenhouse gas, as well as a renewable energy and available carbon source if appropriately-managed (Modin et al., 2007; Zhu et al., 2016). Anaerobic oxidation of methane (AOM) is an important methane sink (Knittel and Boetius, 2009; Knittel et al., 2005). AOM coupled to the microbial reduction of various electron acceptors, such as sulfate (Boetius et al., 2000), nitrate (Haroon et al., 2013), nitrite (Ettwig et al., 2010), Fe(III) and Mn(IV) (Ettwig et al., 2016; Beal et al., 2009), plays a crucial role in mitigating methane emissions to the atmosphere. A recent study has shown that methane can also serve as electron donors for microbial decolorization of methyl orange (MO), a typical azo dye, but the decolorization was seriously inhibited when the concentration of MO was above 100 mg/L due to the high toxicity of azo dyes and its products to microorganisms in SBR (Fu et al., 2019). Therefore, it is necessary to use the appropriate biological technique, in which bacterial aggregates or biofilms are formed to improve the tolerance and adaptation of anaerobic bacteria to xenobiotic compounds, such as aromatic compounds (Donlon et al., 1995; Kargi and Eker, 2005). In addition, methane is poorly soluble (3.5 mg per 100 mL water) (He et al., 2013), thus improving methane transfer for microbe utilization is also very important in biological techniques involving methane-utilizing microbes.
A hollow fiber membrane bioreactor (HfMBR) is a novel and efficient technology to deliver a gaseous substrate to microorganisms (Lai et al., 2016a). Among its advantages, the membrane surface is used as a carrier for microorganism attachment, and can efficiently prevent the microorganisms from being washed out from the system (Syron and Casey, 2008; Cai et al., 2015). In addition, the continuous-flow mode used in the HfMBR can accelerate liquid discharge from the system, which avoids the accumulation of toxic products. These two features are particularly important for the removal of toxic pollutants by slow-growing anaerobes (Shi et al., 2013). To date, the methane-based HfMBR has been successfully used for efficient removal of highly toxic inorganics, such as perchlorate (Luo et al., 2015) and selenate (Lai et al., 2016b; Luo et al., 2018), and heavy metals, such as chromium (Lai et al., 2016a; Lu et al., 2018) and vanadate (Lai et al., 2018a). Meanwhile, methanotrophic archaea usually forms syntrophic consortia with partner bacteria in HfMBR, which ultimately enhance the stability and removal rates of this system to practical application level (Cai et al., 2015; Xie et al., 2017).
Therefore, the aims of this study were to (1) investigate the feasibility of applying methane-based HfMBR as a technology for MO decolorization from synthetic wastewater; (2) evaluate the MO decolorization rate and efficiency by stepwise changing the influent MO concentration and HRT in HfMBR; (3) explore the microbial morphology and community performing MO decolorization in HfMBR. The performance of the HfMBR was determined by measuring the concentration of MO. Microbial morphology in the HfMBR was analyzed by fluorescence in situ hybridization (FISH) and scanning electron microscopy (SEM) analysis. In addition, the key microorganisms performing MO decolorization were identified using a combination of quantitative real-time PCR (qPCR), high-throughput sequencing of the 16S rRNA gene and cloning library construction.
Section snippets
HfMBR set-up
The decolorization of MO was conducted in a laboratory-scale HfMBR. The schematic diagram of the HfMBR system is shown in Fig. 1, the HfMBR contains 100 hollow fibers (0.70 mm inner diameter and 1.03 mm outer diameter) made of polyvinylidene fluoride (PVDF). The total volume of the membrane module is 237 mL, which includes 10 mL of hollow fiber materials, 9 mL of space inside the fibers for gas supply, and 218 mL of space outside the fibers for liquid. The total surface area of the membrane is
Start-up of the HfMBR
In the start-up stage (Stage 1), the HfMBR was operated to establish the biofilm colonization and nitrate was supplied as the sole electron acceptor. After inoculation, a relatively high NO3−-N removal rate of 226 mg/L/d on 0.5 day was observed, and there was evident nitrite accumulation due to the high nitrate removal rate (Fig. 2a). However, subsequently, the removal rate of nitrate gradually decreased and there was no longer nitrite accumulation after 25 days. The NO3−-N removal rate was
Conclusions
A methane-based HfMBR inoculated with an AOM culture was developed and operated to study its MO decolorization capacity with synthetic wastewater. The main findings of this study were:
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MO decolorization achieved a high level with ∼ 100 % decolorization efficiency (HRT = 2 to 1.5 days) and a maximum decolorization rate of 883 mg/L/day (HRT = 0.5 day)
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Microbial community changed significantly after MO decolorization. Methane-related archaea Methanomethylovorans were absolutely the dominant archaea,
Author contributions
Study conception and design:
Raymond Jianxiong Zeng, Fang Zhang
Acquisition of data:
Ya-Nan Bai, Xiu-Ning Wang, Wei Zhang, Jun Wu, Yong-Ze Lu, Liang Fu
Analysis and interpretation of data:
Ya-Nan Bai, Raymond Jianxiong Zeng
Drafting of manuscript:
Ya-Nan Bai, Fang Zhang
Critical revision:
Raymond Jianxiong Zeng, Tai-Chu Lau
Declaration of Competing Interest
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
Acknowledgments
This work was supported by the National Natural Science Foundation of China (51178444, 51878175) and the Program for Innovative Research Team in Science and Technology in Fujian Province University (IRTSTFJ)
References (59)
- et al.
Review paper on current technologies for decolourisation of textile wastewaters: perspectives for anaerobic biotechnology
Bioresour. Technol.
(2007) - et al.
Behaviour of different anaerobic populations on the biodegradation of textile chemicals
J. Hazard. Mater.
(2009) - et al.
Combination of chemical and enzymatic treatment for efficient decolorization/degradation of textile effluent: high operational stability of the continuous process
Biochem. Eng. J.
(2015) - et al.
Enhanced azo dye Reactive Red 2 degradation in anaerobic reactors by dosing conductive material of ferroferric oxide
J. Hazard. Mater.
(2018) - et al.
Monoazo and diazo dye decolourisation studies in a methanogenic UASB reactor
J. Biotechnol.
(2005) - et al.
Decoloration of textile wastewater by means of a fluidized-bed loop reactor and immobilized anaerobic bacteria
J. Hazard. Mater.
(2006) - et al.
The effects of reductant and carbon source on the microbial decolorization of azo dyes in an anaerobic sludge process
Dye. Pigment
(2008) - et al.
Microbial community structure associated with treatment of azo dye in a start-up anaerobic sequenced batch reactor
J. Taiwan Inst. Chem. E
(2015) - et al.
Denitrification with methane as external carbon source
Water Res.
(2007) - et al.
Microbiology and potential applications of aerobic methane oxidation coupled to denitrification (AME-D) process: a review
Water Res.
(2016)
Degradation of organic pollutants by anaerobic methane-oxidizing microorganisms using methyl orange as example
J. Hazard. Mater.
Removal of 2, 4-dichlorophenol and toxicity from synthetic wastewater in a rotating perforated tube biofilm reactor
Process Biochem.
Mdodeling a nitrite-dependent anaerobic methane oxidation process: parameters identification and model evaluation
Bioresour. Technol.
Nitrate reduction by denitrifying anaerobic methane oxidizing microorganisms can reach a practically useful rate
Water Res.
Chromium isotope fractionation during Cr(VI) reduction in a methane-based hollow-fiber membrane biofilm reactor
Water Res.
Decolorization by Caldicellulosiruptor saccharolyticus with dissolved hydrogen under extreme thermophilic conditions
Chem. Eng. J.
Design and evaluation of universal 16S rRNA gene primers for high-throughput sequencing to simultaneously detect DAMO microbes and anammox bacteria
Water Res.
A biofilm model for assessing perchlorate reduction in a methane-based membrane biofilm reactor
Chem. Eng. J.
A new approach to simultaneous ammonium and dissolved methane removal from anaerobic digestion liquor: a model-based investigation of feasibility
Water Res.
Ethyl tert-butyl ether (EtBE) degradation by an algal-bacterial culture obtained from contaminated groundwater
Water Res.
Anaerobic decolorisation of simulated textile wastewater containing azo dyes
Bioresour. Technol.
Decolorization of simulated textile wastewater in an anaerobic–aerobic sequential treatment system
Process Biochem.
Treatment of textile dyeing wastewater using two-phase pilot plant UASB reactor with sago wastewater as co-substrate
Chem. Eng. J.
Detoxification of azo dyes by bacterial oxidoreductase enzymes
Crit. Rev. Biotechnol.
Reductive decolorization of a textile reactive dyebath under methanogenic conditions
Appl. Biochem. Biotechnol.
Decolorization and partial degradation of selected azo dyes by methanogenic sludge
Appl. Biochem. Biotechnol.
Anaerobic oxidation of methane: progress with an unknown process
Annu. Rev. Microbiol.
Diversity and distribution of methanotrophic archaea at cold seeps
Appl. Environ. Microbiol.
A marine microbial consortium apparently mediating anaerobic oxidation of methane
Nature
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