We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
The merits of novel partial nitrification inhibitors: Enhancing nitrogen removal performance while suppressing the spread of resistance genes in partial nitrification-anammox system
AI summary Read the abstract
This study evaluated two novel inhibitors—hexadecyl trimethyl ammonium chloride (ATMAC) and acetaminophen (APAP)—for controlling nitrite-oxidizing bacteria in a partial nitrification-anammox wastewater treatment system over 150 days, achieving 81.74% total nitrogen removal. The inhibitors selectively suppressed unwanted bacterial genes without significantly enriching antibiotic resistance genes in biofilms, though resistance gene leakage into the water phase remained a concern, particularly on polyethylene and polyurethane microplastic carriers.
Hexadecyl trimethyl ammonium chloride (ATMAC) and acetaminophen (APAP) were two novel partial nitrification (PN) inhibitors that effectively suppressed the activity of nitrite-oxidizing bacteria (NOB). However, ATMAC and APAP were considered emerging contaminants, their long-term use as inhibitors may pose environmental risks that requires attention. This study investigated the long-term (150 days) effects of ATMAC and APAP on the nitrogen removal capacity of the partial nitrification-anammox (PNA) system. Microbial community succession and resistance genes (RGs) propagation were also examined on three carriers: polyethylene (PE) carriers of K1 (PEK1), PE microplastics (PE MPs), and polyurethane (PU) MPs. The optimal condition was observed with 0.5 mg/L ATMAC and 2 mg/L APAP, under which the system achieved 81.74% total nitrogen removal. This combination selectively suppressed NOB-associated genes while enriching those of ammonia-oxidizing bacteria and anaerobic ammonium-oxidizing bacteria. Notably, stress induced by 0.5 ATMAC and 2 APAP did not result in significant enrichment of RGs on the biofilm, suggesting a favorable trade-off between performance enhancement and resistance risk. However, the high abundance of RGs in the water phase of the PNA system indicated a potential risk of environmental leakage. Furthermore, among the detected RGs, mexF and qacH-02 (efflux pump genes) consistently maintained high abundance across all samples, representing the primary manifestation of microbial resistance to the inhibitors. In addition, the increase in mobile genetic elements alerted to the risk associated with RGs propagation when using inhibitors.
More Papers Like This
Phenacetin inhibited but acetaminophen stabilized partial nitrification/anammox system: Studies on microbial metabolism and resistance genes in biofilm and plastisphere
AI summary Read the abstract
Common pain relievers like acetaminophen (Tylenol) and phenacetin can end up in wastewater and affect the bacteria used to remove nitrogen pollution from water at treatment plants — this study found that low doses of acetaminophen kept these bacterial systems working well, while phenacetin disrupted them. The researchers also discovered that microplastics in these treatment systems act like magnets for antibiotic-resistance genes, soaking them up far more than other surfaces — a reminder that microplastic pollution may be helping drug-resistant bacteria spread through our water systems.
How anammox responds to the emerging contaminants: Status and mechanisms
AI summary Read the abstract
This review synthesizes research on how emerging contaminants including antibiotics, nanomaterials, heavy metals, and microplastics affect anammox bacteria used in wastewater nitrogen removal, identifying inhibition thresholds and possible recovery mechanisms.
Responses of performance, antibiotic resistance genes and bacterial communities of partial nitrification system to polyamide microplastics
AI summary Read the abstract
Short- and long-term exposure of a partial nitrification bioreactor to polyamide microplastics found that while overall treatment performance was minimally affected, chronic exposure elevated ammonia oxidation rates and shifted bacterial community composition, with enrichment of microplastic-colonizing taxa potentially altering nitrogen removal pathways over time.
Microplastics enhanced the resistant genes spread under disinfectant replacement exposure in partial nitrification-anammox systems
AI summary Read the abstract
Researchers investigated how alternating disinfectant exposure affects the spread of antibiotic resistance genes on microplastic biofilms in wastewater treatment systems. They found that switching between different disinfectants increased the risk of resistance gene transmission, with PET and polyethylene microplastics serving as vectors for both resistant bacteria and nitrogen-removing microorganisms. The study raises concerns that microplastics in wastewater systems may accelerate the spread of antimicrobial resistance under common disinfection practices.
Mechanisms of inhibition and recovery under multi-antibiotic stress in anammox: A critical review
AI summary Read the abstract
This review examines how antibiotics, alongside other emerging pollutants like microplastics and nanomaterials, inhibit the anammox process used in wastewater treatment for nitrogen removal. The researchers detail multiple mechanisms by which antibiotics disrupt these specialized bacteria, including damage to cell membranes, enzyme inhibition, and interference with key metabolic pathways. Understanding these mechanisms is important for developing strategies to maintain effective wastewater treatment in the face of increasing antibiotic contamination.
Research digests by email
When a large batch of papers lands in the Atlas, we read through it and send a short write-up of what stood out.