Influence of organic loading rate on purified terephthalic acid wastewater treatment in a temperature staged anaerobic treatment (TSAT) system: Performance and metagenomic characteristics

The dynamic history of prokaryotic phyla: discovery, diversity and division

Here, I review the dynamic history of prokaryotic phyla. Following leads set by Darwin, Haeckel and Woese, the concept of phylum has evolved from a group sharing common phenotypes to a set of organisms sharing a common ancestry, with modern taxonomy based on phylogenetic classifications drawn from macromolecular sequences. Phyla came as surprising latecomers to the formalities of prokaryotic nomenclature in 2021. Since then names have been validly published for 46 prokaryotic phyla, replacing some established names with neologisms, prompting criticism and debate within the scientific community. Molecular barcoding enabled phylogenetic analysis of microbial ecosystems without cultivation, leading to the identification of candidate divisions (or phyla) from diverse environments. The introduction of metagenome-assembled genomes marked a significant advance in identifying and classifying uncultured microbial phyla. The lumper-splitter dichotomy has led to disagreements, with experts cautioning against the pressure to create a profusion of new phyla and prominent databases adopting a conservative stance. The Candidatus designation has been widely used to provide provisional status to uncultured prokaryotic taxa, with phyla named under this convention now clearly surpassing those with validly published names. The Genome Taxonomy Database (GTDB) has offered a stable, standardized prokaryotic taxonomy with normalized taxonomic ranks, which has led to both lumping and splitting of pre-existing phyla. The GTDB framework introduced unwieldy alphanumeric placeholder labels, prompting recent publication of over 100 user-friendly Latinate names for unnamed prokaryotic phyla. Most candidate phyla remain 'known unknowns', with limited knowledge of their genomic diversity, ecological roles, or environments. Whether phyla still reflect significant evolutionary and ecological partitions across prokaryotic life remains an area of active debate. However, phyla remain of practical importance for microbiome analyses, particularly in clinical research. Despite potential diminishing returns in discovery of biodiversity, prokaryotic phyla offer extensive research opportunities for microbiologists for the foreseeable future.

Development of an internal two-stage upflow anaerobic reactor integrating biostimulation strategies to enhance the degradation of aromatic compounds in wastewater from purified terephthalic acid and dimethyl terephthalate manufacturing processes

In this study, we aimed to establish high-rate biological treatment of purified terephthalic acid (PTA) and dimethyl terephthalate (DMT) wastewater that minimizes the inhibitory effects of high concentration benzoate and acetate. To achieve this, we developed a novel bioreactor system and biostimulation strategy. An internal two-stage upflow anaerobic (ITUA) reactor was operated with (i) a packed bed containing green tuff medium underlying (ii) a compartment seeded with anaerobic granular sludge. Ethylene glycol was amended to stimulate syntrophic interactions. Continuous operation of the system for 1,026 days achieve an organic removal rate of 11.0 ± 0.6 kg COD/m3/d. The abundance of aromatic degraders significantly increased during operation. Thus, we successfully developed a high-rate treatment system to treat wastewater from the PTA/DMT manufacturing processes by activating syntrophs in an ITUA reactor.

Detoxification of typical nitrogenous heterocyclic compound from pharmaceutical wastewater by mixed microbial consortia

Microbial consortia HY3 and JY3 with high degradation efficiency of 2-Diethylamino-4-hydroxy-6-methylpyrimidine (DHMP) were isolated from aerobic and parthenogenic ponds of DHMP-containing pharmaceutical wastewater, respectively. Both consortia were enriched and reached stable degradation performance with a DHMP concentration of 1500 mg L^-1. The DHMP degradation efficiencies of HY3 and JY3 were 95.66% ± 0.24% and 92.16% ± 2.34% under the condition of shaking at 180 r·min^-1 and the temperature of 30 °C for 72 h. And the removal efficiencies of chemical oxygen demand were 89.14% ± 4.78% and 80.30% ± 11.74%, respectively. High-throughput sequencing results indicated that three bacterial phyla of Proteobacteria, Bacteroidetes, and Actinobacteria were dominant in both HY3 and JY3, but their dominances varied. At the genus level, the richness of Unclassified Comamonadaceae (34.23%), Paracoccus (14.75%), and Brevundimonas (13.94%) ranked top three in HY3 whereas Unclassified Comamonadaceae (40.80%), Unclassified Burkholderiales (13.81%) and Delftia (13.11%) were dominant in JY3. The metabolites of DHMP degradation by HY3 and JY3 were analyzed in detail. Two pathways for cleavage of the nitrogenous heterocyclic ring were speculated, one of which was identified for the first time in this study.

Advanced nitrogen removal performance and microbial community structure of a lab-scale denitrifying filter with in-situ formation of biogenic manganese oxides

Advanced nitrogen removal faces the challenges of high operational cost resulted from the additional carbon source and secondary pollution caused by inaccurate carbon source dosage in municipal wastewater. To address these problems, a novel carbon source was developed, which was the oxidation products of refractory organic matters in the secondary effluent of municipal wastewater treatment plant (MWWTP) by in-situ generated biogenic manganese oxides (BMOs) in the denitrifying filter. In the steady phase, the effluent chemical oxygen demand (COD_cr), NO₃^--N and total nitrogen (TN) in the denitrifying filter 2^# with BMOs was 11.27, 9.03 and 10.36 mg/L, and the corresponding removal efficiency was 54.79%, 51.85% and 48.03%, respectively, which was significantly higher than those in the control denitrifying filter 1^# that the removal efficiency of COD_cr, NO₃^--N and TN was only 32.30%, 28.58% and 29.36%, respectively. Kinds of denitrifying bacteria (Candidatus Competibacter, Defluviicoccus, Dechloromonas, Candidatus Competibacter, Dechloromonas, Pseudomonas, Thauera, Acinetobacter, Denitratisoma, Anaerolineae and Denitratisoma) and anammox bacteria (Pirellula, Gemmata, Anammoximicrobium and Brocadia) were identified in the denitrifying filters 1^# and 2^#, which explained why the actual COD_cr consumption (1.55 and 1.44 mg) of reducing 1 mg NO₃^--N was much lower than the theoretical COD_cr consumption. While manganese oxidizing bacteria (MnOB, Bacillus, Crenothrix and Pedomicrobium) was only identified in the denitrifying filter 2^#. This novel technology presented the advantages of no additional carbon source, low operational cost and no secondary pollution. Therefore, the novel technology has superlative application value and broad application prospect.

High-rate cotreatment of purified terephthalate and dimethyl terephthalate manufacturing wastewater by a mesophilic upflow anaerobic sludge blanket reactor and the microbial ecology relevant to aromatic compound degradation

Polyethylene terephthalate (PET) is produced worldwide, mainly as material for plastic drink bottles. PET is produced by polymerization of purified terephthalate (PTA) or dimethyl terephthalate (DMT) with ethylene glycol. During the synthetic manufacturing processes of PTA and DMT, high organic loading wastewater is produced, which is typically treated separately by anaerobic wastewater treatment technologies. Given the high demand for PET, manufacturing plants are expanding globally, which will result in an increase in the amounts of PTA and DMT wastewater in need of treatment. In terms of effective treatment, the cotreatment of PTA and DMT wastewater has several advantages, including lower area and energy requirements. In this study, we examined the performance of an upflow anaerobic sludge blanket (UASB) reactor in cotreating PTA and DMT wastewater with high organic loading, evaluating its removal characteristics after 518 days of continuous operation. In addition, we performed a microbiome analysis of the UASB granular sludge to uncover the microbial interactions and metabolic functions within the reactor. By continuous operation, we achieved an organic removal rate of 6.6 kg m^-3 day^-1. In addition, we confirmed that aromatic compounds in the complex wastewater from the PTA and DMT manufacturing processes are biodegradable in the following order: benzoate > orthophthalate > terephthalate > isophthalate > p-toluic acid. 16S rRNA gene-based network analysis shows that anaerobic Woesearchaeales belonging to phylum Nanoarchaeota has a positive correlation with Methanoregula, Candidatus Methanofastidiosum, and Methanosarcina, suggesting a symbiotic relationship with methanogens in granular sludge. Shotgun metagenomic analysis revealed that terephthalate, isophthalate/orthophthalate, and benzoate were degraded by different members of Pelotomaculaceae and Syntrophorhabdaceae. According to the genomic information, we propose two new possible routes for orthophthalate degradation by the Syntrophorhabdaceae organism.

The fate and behavior mechanism of antibiotic resistance genes and microbial communities in anaerobic reactors treating oxytetracycline manufacturing wastewater

In this study, two parallel-operated expanded granular sludge bed (EGSB) reactors, one used to treat oxytetracycline (OTC) manufacturing wastewater with gradual increase of OTC concentration as experimental reactor and the other fed with the same wastewater without OTC as control reactor, were operated to investigate the behavior of antibiotics resistance genes (ARGs) and mobile genetic elements (MGEs) and their possible relationships with bacterial community among influent, sludge and effluent environments. Though the average absolute abundance of ARGs slightly decreased (0.26 - log), the ARGs' relative abundance normalized to 16S-rRNA gene copy numbers showed a significant upward trend in effluent (2 multiples - increase) and the absolute and relative abundances both extremely increased in anaerobic sludge, indicating that anaerobic treatment process cannot reduce ARGs efficiently, inversely can increase the risk of ARGs through the proliferation of antibiotics resistance bacteria (ARB) under the suppression of OTC. MGEs, bacterial communities and OTC concentration mainly impacted the ARGs profiles, which contributed 88.4% to the variation of ARGs. The differences and correlations of hosts in influent, effluent and sludge were further confirmed by network analysis. Overall, this study enhanced the understanding of the prevalence and transfer of ARGs in OTC production effluents during anaerobic treatment.

Insight into the performance and microbial community profiles of magnetite-amended anaerobic digestion: Varying promotion effects at increased loads

In current study, the enhancement effect of magnetite on anaerobic digestion was evaluated at increased organic loading rate (OLR) from 1.6 to 25.6 kg COD·m^-3·d^-1. The supplement of magnetite enhanced the methane yield by 7-483% accompanied with faster VFAs conversion. Microbial analysis suggested the varied enhancing effect achieved at different OLRs was attributed to different syntrophic interactions triggered by magnetite. More specially, an electroactive syntropy was established between Trichococcus with Methanobacterium at OLR lower than 6.4 kg COD·m^-3·d^-1, while with the OLR increase, more acid fermentative bacteria (Propionimicrobium, Syner-01) were enriched and further enhanced methanogenesis in a syntrophic way with Methanosaeta. Overall, the incorporation of magnetite was a promising approach to achieve efficient anaerobic digestion, OLR was also critical factor affecting the methanogenesis and should be carefully regulated in future application.

Next generation sequencing approaches to evaluate water and wastewater quality

The emergence of next generation sequencing (NGS) is revolutionizing the potential to address complex microbiological challenges in the water industry. NGS technologies can provide holistic insight into microbial communities and their functional capacities in water and wastewater systems, thus eliminating the need to develop a new assay for each target organism or gene. However, several barriers have hampered wide-scale adoption of NGS by the water industry, including cost, need for specialized expertise and equipment, challenges with data analysis and interpretation, lack of standardized methods, and the rapid pace of development of new technologies. In this critical review, we provide an overview of the current state of the science of NGS technologies as they apply to water, wastewater, and recycled water. In addition, a systematic literature review was conducted in which we identified over 600 peer-reviewed journal articles on this topic and summarized their contributions to six key areas relevant to the water and wastewater fields: taxonomic classification and pathogen detection, functional and catabolic gene characterization, antimicrobial resistance (AMR) profiling, bacterial toxicity characterization, Cyanobacteria and harmful algal bloom identification, and virus characterization. For each application, we have presented key trends, noteworthy advancements, and proposed future directions. Finally, key needs to advance NGS technologies for broader application in water and wastewater fields are assessed.

Improved purified terephthalic acid wastewater treatment using combined UAFB-SBR system: At mesophilic and ambient temperature

In this study, a combined UAFB-SBR process was introduced to improve the treatment efficiency of PTA wastewater. The techno-economic feasibility of the process was evaluated in terms of organic removal efficiencies under mesophilic (37 °C) and ambient temperature (15-25 °C) during the long-term run. The lab-scale study revealed that all organic compounds present in the PTA wastewater could be efficiently removed under both mesophilic and ambient temperature, and p-toluic acid is probably the critical pollutant regulating the overall process performance in anaerobic stage, which should be seriously considered. The Miseq Sequencing results suggested that, along with the system temperature variation from mesophilic to ambient temperature, greater effects on bacterial community than archaeal community were detected in the UAFB reactor, while only slight variations were observed in the SBR reactor. Further taxonomy analysis demonstrated that within the UAFB reactor, the syntrophic partnership of Syntrophorhabdus, Syntrophus and Desulfovibrio with hydrogenotrophic methanogens were the main impetus for aromatic organics reduction. In the meanwhile, the intensively identified Thauera and Azoarcus groups were speculated of important roles in the aerobic degradation of aromatic compounds.