Hydraulic retention times as key parameter governing biomethanation of brewery spent grain and system stability in long-term continuously-feeding anaerobic digestion.

The feasibility of converting brewery spent grain (BSG) to biomethane in a mesophilic continuously-stirred tank reactor was demonstrated at various hydraulic retention times (HRTs) of 100, 60, 30, and 20 d. As HRT decreased to 30 d, the biogas and CH production rates increased to 1.40 ± 0.

Stoichiometric analysis and control strategy of partial nitrification for treating dewatering liquid from food-waste methane fermentation.

Methane fermentation is critical for food-waste management; however, effective treatment of its high-ammonium dewatering liquid remains a major challenge. Anammox, a promising candidate for liquid treatment, requires effective pretreatment, such as partial nitrification (PN), to reduce ammonium and generate sufficient nitrite to optimize efficiency. In this study, an airlift reactor was employed to process the dewatering liquid from food-waste methane fermentation.

Elucidation of the stress mechanisms on activated sludge stability induced by yttrium oxide nanoparticles with cytotoxicity: Performance deterioration, biointerface variation and microbial response.

As technoscience advances, widespread use of nanoparticles (NPs) has resulted in environmental risks. This study focuses on the potential stress of 0-200 mg/L yttrium oxide (YO) NPs on the activated sludge stability. YO NPs progressively suppressed nitrification, caused significant NO accumulation (200 mg/L) and diminished activities of key functional enzymes.

A chemically enhanced primary treatment and anammox-based process for sustainable municipal wastewater treatment: The advantage and application prospects.

Low-carbon nitrogen removal, bioenergy production, and phosphorus recovery are key goals for sustainable municipal wastewater treatment. Traditional activated sludge processes face an energy demand conflict. Anaerobic ammonium oxidation (Anammox) offers a solution to this issue, with the A-B process providing a sustainable approach.

Changes in methanogenic performance and microbial community during gradual transition from co-digestion with food waste to mono-digestion of rice straw.

This study investigated the performance and phase-specific characteristics of mesophilic co-digestion of food waste (FW) with rice straw (RS) at different RS proportions (40 %, 60 %, and 80 %), as well as mono-digestion of RS. The system achieved optimal performance at 40 % RS content, with a methane yield of 383.8 mL/g-VS and cellulose removal efficiency exceeding 75 %.

Start-up of Anammox-HAP in IC reactors: Revelation of sludge characteristics and microbial community structure.

The scarcity of seed sludge poses a significant barrier to the advancement of anaerobic ammonia oxidation (anammox) process. In this investigation, two alternative sludge (anaerobic granular sludge (AGS) and activated flocculent sludge (AFS)) were employed to start up the anammox process in internal circulation (IC) reactors with the hydroxyapatite (HAP) strategy. Both reactors achieved rapid start-up on days 83 and 53, respectively.

Revealing microbial compatibility of partial nitritation/Anammox biofilm from sidestream to mainstream applications: Origins, dynamics, and interrelationships.

Biofilms offer a solution to the challenge of low biomass retention faced in mainstream partial nitritation/Anammox (PN/A) applications. In this study, a one-stage PN/A reactor derived from initial granular sludge was successfully transformed into a biofilm system using shedding carriers. Environmental stressors, such as ammonium nitrogen concentration and organic matter, significantly affected the competitive dynamics and dominant species composition between Ca.

CO removal from biogas improved stable treatment of low-alkalinity municipal wastewater using anaerobic membrane bioreactor.

This study addressed a less-reported issue: the insufficient alkalinity encountered when anaerobic membrane bioreactors (AnMBRs) are used to treat municipal wastewater (MWW). In the present study, a 20-L AnMBR was initiated at an MWW treatment plant. During the initial startup, a continuous decrease in pH was observed.

Using amino acid waste liquid as functional supplement to change microbial community in up-flow anaerobic sludge blanket treatment of methanolic wastewater.

In this study, amino acid waste liquid was employed as a functional supplement (designated as amino acid-rich FS) in the up-flow anaerobic sludge blanket (UASB) treatment of methanolic wastewater. The effect of amino acid-rich FS was evaluated through repeated batch tests, showing that a 0.5% and 1% dosage increased the maximum methane production rate by 93.

Anaerobic treatment of nitrogenous industrial organic wastewater by carbon-neutral processes integrated with anaerobic digestion and partial nitritation/anammox: Critical review of current advances and future directions.

Anaerobic digestion combined with partial nitritation/anammox technology holds promising potential for the carbon-neutral treatment of nitrogenous industrial organic wastewater, boasting remarkable advantages in effective removal of both organic matters and nitrogen, bio-energy recovery and carbon emission reduction. This study provides a concise overview of the development and advantages of anaerobic digestion combined with partial nitritation/anammox technology for treating nitrogenous industrial organic wastewater. The process excels in removing organic matter and nitrogen, recovering bio-energy, and reducing carbon emissions, compared to traditional physicochemical and biological methods.

Comparison of the short- and long-term effects of zinc ions on the anaerobic mesophilic co-digestion of food waste and waste activated sludge: Digester performance, antibiotic resistance gene reduction and the microbial community.

Heavy metals contained in waste activated sludge (WAS), especially zinc ions, have an inhibitory effect on the anaerobic digestion. However, the effects of zinc ions on digester performance, antibiotic resistance genes (ARGs) reduction, and the microbial community involved in the anaerobic mesophilic co-digestion (AcoD) of WAS and food waste (FW) have not been fully characterized. Therefore, batch trials and continuous stirred tank reactors were used under different zinc-ion concentrations.

Changes in activity and microbial community composition of Anammox-HAP granules during long-term preservation under different conditions.

Preservation of anammox granular sludge is important for anammox technology applications. Although previous studies have explored preservation methods, their long-term effects on microbial communities and functional genes remain underexplored. This study investigated the long-term preservation of anammox-hydroxyapatite (HAP) granules with storage durations of up to six years and examined the effects of different preservation methods.

Pure water and resource recovery from municipal wastewater using high-rate activated sludge, reverse osmosis, and mainstream anammox: A pilot scale study.

In response to the escalating global water scarcity and the high energy consumption associated with traditional wastewater treatment plants, there is a growing demand for transformative wastewater treatment processes that promise greater efficiency and sustainability. This study presents an innovative approach for municipal wastewater treatment that integrates high-rate activated sludge with membrane bio-reactor (HRAS-MBR), reverse osmosis (RO) and partial nitrification-anammox (PN/A). With an influent of 8.

Synergic treatment of domestic wastewater and food waste in an anaerobic membrane bioreactor demo plant: Process performance, energy consumption, and greenhouse gas emissions.

Ambient operation and large-scale demonstration have limited the implementation and evaluation of anaerobic membrane bioreactors (AnMBRs) for low-strength wastewater treatment. Here, we studied these issues at an AnMBR demo plant that treats domestic wastewater and food waste together at ambient temperatures (7-28 °C). At varied hydraulic retention times (HRTs, 8-42 h), the AnMBR achieved a COD removal efficiency and biogas production of 80.

Synergetic association of hydroxyapatite-mediated biofilm and suspended sludge enhances resilience of partial nitrification/anammox (PN/A) system treating high-strength anaerobic membrane bioreactor (AnMBR) permeate.

A single-stage partial nitrification/anammox (PN/A) system with biocarriers was used to treat the permeate from an anaerobic membrane reactor (AnMBR) processing organic fraction of municipal solid wastes. The suitable Ca/P ratio and high pH in the AnMBR permeate facilitated hydroxyapatite (HAP) formation, enhancing the biofilm attachment and the settleability of suspended sludge. This maintained sufficient biomass and a stable microbial structure after flushing to mitigate the free nitrous acid inhibition.

Biokinetic and microbial insights into regulatory mechanisms of long-chain fatty acid degradation during food waste-lipid co-digestion within anaerobic membrane bioreactor.

This study investigated the effects of varying lipid ratios on the anaerobic co-digestion of high-lipid food waste (FW) in a mesophilic anaerobic membrane bioreactor (AnMBR). At a lipid concentration of 5 %, optimal biogas production (3.84 L/L/d) and lipid removal efficiency (78 %) were achieved; however, increasing lipid concentrations resulted in significant accumulations of long-chain fatty acids (LCFAs) and volatile fatty acids (VFAs).

Nondestructive and three-dimensional visualization by identifying elements using synchrotron radiation microscale X-ray CT reveals microbial and cavity distributions in anaerobic granular sludge.

Unlabelled: We developed a nondestructive three-dimensional microbial visualization method utilizing synchrotron radiation X-ray microscale computed tomography to better understand the relationship between microorganisms and their surrounding habitats. The method was tested and optimized using a mixture of axenic and . The osmium-thiocarbohydrazide-osmium method was used to stain all the microbial cells, and gold hybridization was used to detect specific phylogenetic microbial groups.

Recovery of ammonia nitrogen from simulated reject water by bipolar membrane electrodialysis.

Ammonia monohydrate (NH·HO) is an important chemical widely used in industrial, agricultural, and pharmaceutical fields. Reject water is used as the raw material in self-built bipolar membrane electrodialysis (BMED) to produce NH·HO. The effects of electrode materials, membrane stack structure, and operating conditions (current density, initial concentrations of the reject water, and initial volume ratio) on the BMED process were investigated, and the economic costs were analyzed.

Enhanced sludge granulation and stable performance of an anammox expanded granular sludge bed (EGSB) reactor through the utilization of hydroxyapatite (HAP) particles.

The reuse of hydroxyapatite particles (HAPs) as a granulation activator for anammox sludge was explored to address the remaining issues of time-consuming and unstable granular structure in anammox granulation. During the granulation, nitrogen removal capacity from 2.8 to 13.

Metatranscriptomics-guided genome-scale metabolic reconstruction reveals the carbon flux and trophic interaction in methanogenic communities.

Background: Despite rapid advances in genomic-resolved metagenomics and remarkable explosion of metagenome-assembled genomes (MAGs), the function of uncultivated anaerobic lineages and their interactions in carbon mineralization remain largely uncertain, which has profound implications in biotechnology and biogeochemistry.

Results: In this study, we combined long-read sequencing and metatranscriptomics-guided metabolic reconstruction to provide a genome-wide perspective of carbon mineralization flow from polymers to methane in an anaerobic bioreactor. Our results showed that incorporating long reads resulted in a substantial improvement in the quality of metagenomic assemblies, enabling the effective recovery of 132 high-quality genomes meeting stringent criteria of minimum information about a metagenome-assembled genome (MIMAG).

A soft-sensor approach for predicting an indicator virus removal efficiency of a pilot-scale anaerobic membrane bioreactor (AnMBR).

The anaerobic membrane bioreactor (AnMBR) is a promising technology for not only water reclamation but also virus removal; however, the virus removal efficiency of AnMBR has not been fully investigated. Additionally, the removal efficiency estimation requires datasets of virus concentration in influent and effluent, but its monitoring is not easy to perform for practical operation because the virus quantification process is generally time-consuming and requires specialized equipment and trained personnel. Therefore, in this study, we aimed to identify the key, monitorable variables in AnMBR and establish the data-driven models using the selected variables to predict virus removal efficiency.