Insights into the migration mechanism of extracellular antibiotic resistance genes during struvite recovery using synthetic wastewater.

In recent, the complexation of extracellular antibiotic resistance genes (eARGs) with environmental particles has been getting significant concerns, since eARGs can consequently disseminate, propagate and pose ecological risks to the environment. This study focused on eARGs complexing with struvite (MgNHPO·6HO) particles in struvite recovery by using synthetic wastewater. The adsorption capacities of eARGs by struvite crystals with different morphologies were firstly examined.

A novel strategy for improving ammonia resistance of acidogenesis using domesticated sludge combined with nZVI addition in an ambient anaerobic digestion system.

High ammonia stress, which inhibited the performance and stability of anaerobic digestion (AD) systems, is considered a bottleneck problem. To improve the performance of ambient acidogenic AD system under high ammonia stress, three different strategies were developed, including native sludge with nano zero valent iron (nZVI) addition (S), domesticated sludge enriched with homoacetogens with no additive (S) and domesticated sludge with nZVI addition (S). All groups were operated at ambient temperature (24 ± 1 °C).

Ethanol-mediated Anaerobic Digestion: Functional Bacteria and Metabolic Pathways.

Ethanol-mediated Anaerobic digestion (Ethanol-AD) is a biological process that converts organic waste into biogas, predominantly composed of methane (CH₄), hydrogen (H₂), and carbon dioxide (CO₂), through the breakdown of complex organic materials while ethanol is an intermediate metabolite. Ethanol improves the digestion of complex organic waste by serving as an electron precursor for interspecies electron transfer, leading to enhanced biogas production. It further serves as a substrate for acetogens or syntrophic bacteria, while mean its oxidation leads to acetate formation, which methanogens can then consume to generate methane.

A novel strategy for enhancing high solid anaerobic digestion of fecal slag and food waste using percolate recirculation and dosage of nano zero-valent iron.

To speed up reaching UN Sustainable Development Goal 6 for safe sanitation by 2030, integrating high-solid anaerobic digestion (HSAD) into decentralized systems could recycle fecal slag (FS) and food waste (FW), aiding a circular economy and toilet revolution. In this study, a percolate recirculation system and conductive material were used to improve mass transfer, stability, and enhance methane production in HSAD of FS and FW. This setup consists of a percolate tank and a digester tank, where nano-zero valent iron (nZVI) was dosed in the percolate tank (P) and the digester tank (P) and compared with a control with no additive (P).

Revolutionizing sanitation: Valorizing fecal slags through co-digesting food waste at high-solid content and dosing metallic nanomaterials for anaerobic digestion stability.

To achieve the UN Sustainable Development Goals (SDGs) and the China Toilet Revolution on a global scale, it is crucial to implement a decentralized sanitation management system in developing countries. Fecal slags (FS) generated from septic tanks of toilets pose a challenge for remote villages. This study sought to resourcefully utilize FS through co-digesting with food waste (FW) under high-solid anaerobic co-digestion (HSAD).

Multi-omics analysis unravels effects of salt and oil on substance transformation, microbial community, and transcriptional activity in food waste anaerobic digestion.

In this study, through quantitative detection of key substances and enzyme activities, an integrated analysis of 16S rRNA sequencing and metatranscriptomics revealed the mechanisms by which salt and oil influence the biotransformation process during anaerobic digestion (AD). The results demonstrated that a salt concentration of 6 g/L promoted lipid metabolism and hydrogenotrophic methanogenesis, while inhibiting the acetoclastic pathway. An oil concentration of 5 g/L facilitated the expression of key enzyme-encoding genes involved in β-oxidation of long-chain fatty acids, transcription, and acetoclastic methanogenesis.

Local environment, surface characteristics and stochastic processes shape the dynamics of urban dustbin surface microbiome.

Dustbins function as critical infrastructures for urban sanitation, creating a distinct breeding ground for microbial assemblages. However, there is no information regarding the dynamics of microbial communities and the underlying mechanism for community assembly on dustbin surfaces. Here, surface samples were collected from three sampling zones (business building, commercial street and residential community) with different types (kitchen waste, harmful waste, recyclables, and others) and materials (metallic and plastic); and distribution pattern and assembly of microbial communities were investigated by high-throughput sequencing.

Revisiting China's domestic greenhouse gas emission from wastewater treatment: A quantitative process life-cycle assessment.

The wastewater treatment industry could alleviate water pollution but consume a large amount of energy and resources. China has over 5000 centralized domestic wastewater treatment plants and produces an unignorable amount of greenhouse gases (GHG). By considering the wastewater treatment, wastewater discharge, and sludge disposal processes, and employing the modified process-based quantification method, this study quantifies wastewater treatment's on-site and off-site GHG emissions across China.

Synchronously recovering different nutrient ions from wastewater by using selective electrodialysis.

Digestive slurry normally contains various nutrient ions with high concentrations, including NH, PO, K, Mg, Ca and SO, which is a resource pool for nutrient recovery. In this study, a synchronously cationic and anionic selective electrodialysis (SCAE) was developed to recover anionic and cationic nutrient ions. Results showed that SCAE could synchronously recover more than 85.

Inoculating indoleacetic acid bacteria promotes the enrichment of halotolerant bacteria during secondary fermentation of composting.

The secondary fermentation stage is critical for stabilizing composting products and producing various secondary metabolites. However, the low metabolic rate of mesophilic bacteria is regarded as the rate-limiting stage in composting process. In present study, two indoleacetic acid (IAA)-producing bacteria (Bacillus safensis 33C and Corynebacterium stationis subsp.

Screening the functions of modified rice straw biochar for adsorbing manganese from drinking water.

The seasonal out-of-limit of manganese ions (Mn) in the drinking water reservoirs is an intractable problem to water supply, which can pose a threat to the human health. In this study, the removal of Mn by using pristine (BC), pre-alkali (Pre-BC) and post-alkali (Post-BC) modified biochar originating from rice straw was investigated. The maximum adsorption capacities obtained for BC, Pre-BC, and Post-BC were 20.

Semi-solid anaerobic co-digestion of source-separated fecal slag and food waste: focusing on methane production, ecological risk assessment, and quality evaluation as fertilizer.

Toilet revolution is driven by the urgent need for solutions to improve sanitation and access to high-quality organic fertilizer for rural areas, which is tagged "resource recovery from human waste." This study provides a possible solution via semi-solid anaerobic co-digestion (Aco-D) of source-separated fecal slag (SFS) and food waste (FW) (3:1). A comprehensive investigation of Aco-D at different inoculum/substrate ratios (ISR) was conducted.

Morphological crystal adsorbing tetracyclines and its interaction with magnesium ion in the process of struvite crystallization by using synthetic wastewater.

Struvite (MgNHPO·6HO) crystallization is a promising method of phosphorus recovery from wastewater. As for digestive livestock wastewater, the extensive residues of antibiotics could induce struvite recovery to spread antibiotic resistance and thereafter pose ecological risks to the environment. In this study, struvite crystals with different morphologies were produced from synthetic swine wastewater, and tetracyclines (TCs) adsorbing capacities were investigated.

Quantification of DOM effects on tetracyclines transport during struvite recovery from swine wastewater.

Struvite (MgNHPO·6HO) recovered from livestock wastewater may impose a pharmacological threat to the environment, due to the extensive existence of antibiotics in the wastewater. In this study, tetracyclines (TCs) were selected as the typical antibiotics, and the individual processes of dissolved organic matters (DOM) evolution and their effects on TCs migration in struvite recovery from swine wastewater were discriminated and quantified. Results revealed that TCs transport was contributed by the adsorption of pure struvite crystals, struvite adsorbing DOM-TCs complex and DOM aggregation, which occupied 2.

Engineered biochars for recovering phosphate and ammonium from wastewater: A review.

Biochar has gained great scientific attention as a promising agent for agricultural and environmental applications. A variety of biochars with excellent properties such as high porosity, surface area and functional groups have been developed for nutrients recovery from wastewater. Compared to pristine biochar, engineered biochar with enlarged surface area and abundant functional groups has been prepared which shows a new type of carbon-based material with enhanced adsorption potential for nutrients in wastewater.

Dissolving the high-cost with acidity: A happy encounter between fluidized struvite crystallization and wastewater from activated carbon manufacture.

Production of wood-based activated carbon (WAC) generates large volume of highly acidic and phosphate-rich wastewater. Currently, the routine treatment (i.e.

Struvite crystallization induced the discrepant transports of antibiotics and antibiotic resistance genes in phosphorus recovery from swine wastewater.

Struvite (MgNHPO·6HO) crystallization is one of important methods of phosphorus recovery from wastewater. As to livestock wastewater, the high-strength occurrence of antibiotics and antibiotic resistance genes might induce struvite recovery to spread antibiotic resistance to the environment. However, limited information has been reported on the simultaneous transport of antibiotics and ARGs in struvite recovery.

Interactions among low-molecular-weight organics, heavy metals, and Fe(III) during coagulation of landfill leachate nanofiltration concentrate.

The generation of landfill leachate nanofiltration concentrate (LLNC) has been a dilemma for leachate treatment plants because it contains large amounts of refractory organics with low molecular weight (LMWO), as well as heavy metals (HMs), and is difficult to handle. The coagulation removal of LMWOs is a significant challenge, as is the removal of HMs bonded to LMWOs. In this study, coagulation through the dosing of FeCl was used to remove LMWOs and HMs from LLNC.

Fractionating various nutrient ions for resource recovery from swine wastewater using simultaneous anionic and cationic selective-electrodialysis.

Different from current nutrient recovery technologies of recovering one or two nutrient components (PO or NH) from wastewater, this study aimed to fractionate various nutrient anions and cations simultaneously, including PO, SO, NH, K, Mg and Ca, into several streams. The recovered streams could be further paired together to produce high-value products. A novel electrodialysis process was developed by integrating monovalent selective anion and cation exchange membranes into an electrodialysis stack.

Comparative study of heavy metal residues in struvite products recovered from swine wastewater using fluidised bed and stirred reactors.

Struvite (MgNHPO·6HO) crystallisation is a promising approach for phosphorus recovery from swine wastewater. Currently, intensive pig feeding has made heavy metals (HMs) extensive in swine wastewater; therefore, significant amounts of HMs have been detected in struvite recovery products. In this study, the HM residues in the struvite products recovered from stirred and fluidised bed reactors were investigated.