Treatment and nutrient recovery of synthetic flowback water from shale gas extraction by air‐cathode (PMo/CB) microbial desalination cells

Abstract

BACKGROUND: Due to the rapid development of shale gas extraction, the treatment of flowback water (FW) is becoming one major challenge because of its high saline, high ammonium (NH 4 +), high phosphorus (PO 4 3−), and complex organic contents. This study aimed to treat the high-salinity synthetic FW and recover nutrient using the air-cathode (PMo/CB) microbial desalination cells (MDCs). RESULTS: The removal efficiency of chemical oxygen demand (COD) exceeded 90% along with an electricity generation of 105.6 mW m −2. The highest removal and the recovery efficiency of 300 mg L −1 NH 4 + and 100 mg L −1 PO 4 3− were 65.6 ± 19.0% and 75.8 ± 32.0%, 52.6% and 57.8%, respectively. High-throughput sequencing analysis of anodic biofilms indicated that Firmicutes, Bacteroidetes, and Proteobacteria enriched at high influent NH 4 + concentration were responsible for producing electricity and degrading complex organics. Two denitrifying bacteria, Trichococcus and Marinobacterium, promoted the COD removal and also improved the electricity generation. Rhodococcus, a kind of heterotrophic nitrification-denitrification bacteria, contributed to nitrification in the cathodic chamber along with enhancing the denitrifying degradation of COD. Nitrincolaceae, capable of heterotrophic nitrate reduction to ammonium, were favorable to the recovery of NH 4 +. CONCLUSIONS: Overall results concluded that PMo/CB-MDC could be a promising alternative technique for the efficient treatment of FW and a pretreatment process for separating nutrient from the recovery chamber.

Enhancing the anode performance of microbial fuel cells in the treatment of oil-based drill sludge by adjusting the stirring rate and supplementing oil-based drill cuttings

“…2 the electrode and electrolyte slows due to the the ore from a high concentration of OBDCs, thereby leading to adverse effects on the conductivity of extracellular electrons. Additionally, a maximal current density of 2.66 A/m 2 was recorded at 2 g/L OBDCs, which was 1.6 times that of synthetic owback wastewater treatment in air cathode MFCs (under the same external resistance) as measured by Yang et al (Yang et al 2020a). This further demonstrated that the activity of electricity-producing microorganisms was the highest, and the oxidation decomposition rate of organic matter may have been the fastest at 2 g/L.…”

Shifts in Soil Microbial Community Composition, Function, and Co-occurrence Network of Phragmites australis in the Yellow River Delta

“…Owing to the strong environmental adaptability and reproductive ability of Ascomycota, its relative abundance was an absolute advantage in each sample, which has also been reported in a variety of habitats, such as pioneer forests and tropical oligotrophic peatlands (Zhong et al, 2018;Morrison et al, 2021). At the family level, the bacterial community was mainly composed of Methlophagaceae, Desulfobulbaceae, Flavobacteriaceae, Nitrincolaceae, and Marinobacteraceae, which were widely distributed in many coastal wetland soils (Zhang et al, 2012;Risgaard-Petersen et al, 2015;Chen et al, 2020;Yang et al, 2021). Desufobulbaceae, regarded as 'cable bacteria' , was involved in the formation of a centimetre-deep suboxic zone in marine sediment through their role in the electrical couple of sulfide oxidation and oxygen reduction (Risgaard-Petersen et al, 2015).…”

“…At the family level, the bacterial community was mainly composed of Methlophagaceae, Desulfobulbaceae, Flavobacteriaceae, Nitrincolaceae, and Marinobacteraceae, which were widely distributed in many coastal wetland soils ( Zhang et al, 2012 ; Risgaard-Petersen et al, 2015 ; Chen et al, 2020 ; Yang et al, 2021 ). Desufobulbaceae, regarded as ‘cable bacteria’, was involved in the formation of a centimetre-deep suboxic zone in marine sediment through their role in the electrical couple of sulfide oxidation and oxygen reduction ( Risgaard-Petersen et al, 2015 ).…”

Highly Contaminated Marine Sediments Can Host Rare Bacterial Taxa Potentially Useful for Bioremediation

“…To gain a deeper insight on the rare portion of the gammaproteobacterial diversity, we conducted a higher-level taxonomic resolution analysis, which indicated that a total of eight gammaproteobacterial families were actually not rare locally (i.e., >1% contribution in at least one site), including Cycloclasticaceae, Halieaceae, KI89A clade, Nitrincolaceae, Rhodocyclaceae, Thioalkalispiraceae, Thiotrichaceae, and UBA10353 marine group ( Figure 4B ). All of these families include members recently reported to be particularly abundant in naturally-rich and/or contaminated environments that display high concentrations of HMs and/or hydrocarbons ( Gołębiewski et al, 2014 ; Singleton et al, 2015 ; Yang et al, 2016 , 2020 ; Suzuki et al, 2019 ; Bergo et al, 2020 ; Noirungsee et al, 2020 ; Sun et al, 2020 ). Notably, Cycloclasticaceae, Halieaceae, and Rhodocyclaceae, well known for their ability to degrade hydrocarbons, showed a peak in the site most contaminated by PAHs (S3; Figure 4B ; Table 1 ).…”