Applying side-stream gas recirculation to promote anaerobic digestion of food waste under ammonia stress: Overlooked impact of gaseous atmospheres on microorganisms.

High ammonia concentrations can be toxic to microorganisms, leading to the accumulation of hydrogen (H) and acids in anaerobic digestion (AD) system. In this study, a side gas recycling strategy (SGR), coupled with a primary reactor and a small side-stream reactor, which recirculates biogas between primary reactor and side reactor was employed to mitigate ammonia inhibition. This approach enabled the mesophilic side-stream gas recirculation system (SMGR) and the thermophilic side-stream gas recirculation system (STGR) to ultimately withstand ammonia stress levels of 2.

Improved anaerobic digestion of food waste under ammonia stress by side-stream hydrogen domestication.

High ammonia concentration inhibits archaea's activity, causing the accumulation of H and acetate, which suppresses methane production in anaerobic digestion (AD). The study aimed to enhance microbial hydrogen metabolism through a side-stream hydrogen domestication (SHD) strategy, which involves applying hydrogen stimulation to a portion of the sludge separately. SHD maintained a stable methane yield of 407.

Analysis of factors influencing the energy efficiency in Chinese wastewater treatment plants through machine learning and SHapley Additive exPlanations.

Wastewater treatment plants (WWTPs) contribute significantly to the control of pollution in water. However, they are significant energy consumers. Identifying the factors influencing energy consumption is crucial for enhancing the energy efficiency of WWTPs.

Enhancing volatile fatty acids production from waste activated sludge: The role of pretreatment by -bis(carboxymethyl)-l-glutamate (GLDA).

N,N-bis(carboxymethyl)-l-glutamate (GLDA) is an eco-friendly chelating agent that effectively extracts multivalent metal ions from waste activated sludge (WAS) flocs, which could potentially alter their structure. However, the effect of GLDA on the production of volatile fatty acids (VFAs) from WAS is not well known. Here, we demonstrate that pretreatment with GLDA at a concentration of 200 mmol per kg VSS results in a significant increase of 142% in extractable extracellular polymeric substances and enhances the total VFAs yield by 64% compared to untreated samples.

Metaproteomics analysis of anaerobic digestion of food waste by the addition of calcium peroxide and magnetite.

Adding trace calcium peroxide and magnetite into a semi-continuous digester is a new method to effectively improve the anaerobic digestion of food waste. However, the microbial mechanism in this system has not been fully explored. Metaproteomics further revealed that the most active and significantly regulated genus had formed a good cooperative relationship with and in the system.

Ascorbic acid reduction pretreatment enhancing metal regulation to improve methane production from anaerobic digestion of waste activated sludge.

Conversion of waste activated sludge (WAS) to methane by anaerobic digestion (AD) is often limited by the slow rate of hydrolysis, and the presence of metal ions in sludge is regarded as a critical factor hindering sludge hydrolysis. This study developed a novel strategy to remove Fe from WAS by using ascorbic acid (VC) as a reducing agent under acidic conditions. The feasibility of reduction pretreatment in improving methane production of AD and its intrinsic mechanism were investigated.

Enhancement of anaerobic digestion of high salinity food waste by magnetite and potassium ions: Digestor performance, microbial and metabolomic analyses.

The study investigated the effectiveness of magnetite and potassium ions (K) in enhancing anaerobic digestion of high salinity food waste. Results indicated that both magnetite and K improved anaerobic digestion in high-salt environments, and their combination yielded even better results. The combination of magnetite and K promoted microorganism activity, and resulted in increased abundance of DMER64, Halobacteria and Methanosaeta.

Improving mesophilic anaerobic digestion of food waste by side-stream thermophilic reactor: Activation of methanogenic, key enzymes and metabolism.

Anaerobic digestion (AD) is a favorable way to convert organic pollutants, such as food waste (FW), into clean energy through microbial action. This work adopted a side-stream thermophilic anaerobic digestion (STA) strategy to improve a digestive system's efficiency and stability. Results showed that the STA strategy brought higher methane production as well as higher system stability.

The modified properties of sludge-based biochar with ferric sulfate and its effectiveness in promoting carbon release from particulate organic matter in rural household wastewater.

The scarcity of carbon sources presents a significant challenge for the bio-treatment of rural domestic wastewater (RDW). This paper presented an innovative approach to address this issue by investigating the supplementary carbon source through in-situ degradation of particulate organic matter (POM) facilitated by ferric sulfate modified sludge-based biochar (SBC). To prepare SBC, five different contents of ferric sulfate (0%, 10%, 20%, 25%, and 33.

Conductive materials enhance microbial salt-tolerance in anaerobic digestion of food waste: Microbial response and metagenomics analysis.

Previous studies have shown that high salinity environments can inhibit anaerobic digestion (AD) of food waste (FW). Finding ways to alleviate salt inhibition is important for the disposal of the growing amount of FW. We selected three common conductive materials (powdered activated carbon, magnetite, and graphite) to understand their performance and individual mechanisms that relieve salinity inhibition.

Effect of granular activated carbon and chloroform on chain elongation with simple substrate ethanol and acetate.

Chain elongation is a promising technology for production of medium-chain fatty acids (MCFAs). Granular activated carbon (GAC) is commonly used in anaerobic fermentation. Low level CHCl can inhibit methanogenesis and homoacetogenesis at the same time.

Gestational exposure to perfluoroalkyl substances is associated with placental DNA methylation and birth size.

DNA methylation is one potential mechanism for the effects of gestational exposure to perfluoroalkyl substances (PFASs) on fetal growth. We investigated 180 pregnant women who participated in a cohort study conducted in Tangshan City, Northern China, and determined the concentrations of 11 PFASs and the methylation of two genes related to fetal growth [insulin-like growth factor 2 (IGF2) and nuclear receptor subfamily 3 group C member 1 (NR3C1)] and one surrogate marker for global methylation [long interspersed nuclear element-1 (LINE-1)] in placenta tissue. Multiple linear regression analysis was performed to examine the associations of log transformed PFASs with the DNA methylation and birth size.

Ammonia Recovery from Wastewater as a Fuel: Effects of Supporting Electrolyte on Ammonium Permeation through a Cation-Exchange Membrane.

Electrodeionization (EDI) is used to recover ammonia from wastewater as a fuel, but how its performance for ammonia recovery is affected by the supporting electrolyte is not very clear. This study involved experimental tests and theoretical calculations on NH recovery, NH permeation, and NH and Na interacting with the functional groups in a cation exchange membrane (CEM) using NaSO as the supporting electrolyte. The results demonstrated that a low concentration (≤0.

Exposure to perfluoroalkyl substances was associated with estrogen homeostasis in pregnant women.

Previous studies have suggested that perfluoroalkyl substances (PFASs) can act as endocrine disruptors, but few studies have investigated the effects of serum PFASs on estrogen homeostasis during pregnancy. The present study included 557 pregnant women in Tangshan City, North China, and determined 11 serum PFASs in the early term of pregnancy and three typical estrogens (estrone (E), estradiol (E) and estriol (E)) in the early (n = 557), middle (n = 339), and late (n = 286) terms of pregnancy. Sociodemographic factors and diet information were obtained by structured questionnaires.

Mechanical Properties of Al Foams Subjected to Compression by a Cone-Shaped Indenter.

Indentation tests and numerical simulations were conducted to investigate the effects of the indenter parameters (diameter and cone angle) and the relative density of Aluminum (Al) foams on the deformation mechanism of closed-cell Al foams, load response, and energy-absorbing capability. The results demonstrated that the densification occurred below the indenter, and cell tearing and bending occurred on both sides of the indenter, while the lateral plastic deformation insignificantly took place during the indentation tests. The load response and absorbed energy per unit volume dramatically increased with the cone angle of the indenter and the relative density of Al foams.

Serum perfluoroalkyl substances in relation to lipid metabolism in Chinese pregnant women.

Laboratory and epidemiologic studies suggested that exposure to perfluoroalkyl substances (PFASs) could affect lipid metabolisms, but data remain limited for pregnant women. A total of 436 pregnant women were selected in Tangshan City, North China. Serum levels of 11 PFASs were determined in the early term of pregnancy.

Serum Bisphenol A, glucose homeostasis, and gestational diabetes mellitus in Chinese pregnant women: a prospective study.

Lab studies have suggested that exposure to Bisphenol A (BPA) could disturb glucose homeostasis, but epidemiologic studies are limited and show inconsistent results for pregnant women. For this, 535 pregnant women were selected from a pregnant women cohort established in Tangshan City in North China between 2013 and 2014. Serum concentrations of BPA were measured in the early term of pregnancy, and fasting glucose and insulin levels were repeatedly measured in each of three terms of pregnancy (early, middle, and late).

Serum phytosterols associate with T helper 1 cytokine concentration in pregnant women.

The dietary phytosterols have been demonstrated to modulate CD4 T-cell polarization in cells, animals, and humans. However, T helper (Th)1/Th2 dichotomy has rarely been correlated with phytosterols during pregnancy. The present study investigated associations between the serum cytokines and serum phytosterols in 100 pregnant women at 34- to 37-week gestation and their offspring.

Energy-Efficient Single-Stage Nitrite Shunt Denitrification with Saline Sewage through Concise Dissolved Oxygen (DO) Supply: Process Performance and Microbial Communities.

Single-stage nitrite shunt denitrification (through nitrite rather than nitrate) with low dissolved oxygen (DO) supply is a better alternative in terms of energy-efficiency, short-footprint, and low C/N-ratio requirement. This study investigates the optimal DO level with temperature effect, with saline sewage at the fixed hydraulic and solids retention times of 8 h and 8 d, respectively. Moreover, 16S rRNA gene sequencing analysis corresponding with total nitrogen (TN) and chemical oxygen demand (COD) removals in each operating condition were performed.

Increasing ammonia recovery from high-level ammonium wastewater via adding sodium sulfate to prevent nitrogen generation in the cathode.

The high-level ammonium-nitrogen (NH-N) is a contaminant for aqueous environment but a potential hydrogen fuel. This study investigated an approach of increasing ammonia recovery via adding sodium sulfate of 0-1.5 M to prevent from nitrogen generation.

Distribution and human health risk assessment of antibiotic residues in large-scale drinking water sources in Chongqing area of the Yangtze River.

Antibiotic contamination in drinking water sources has been increasingly prominent in recent years. The water quality in the Chongqing area is not only essential for the local people but also is crucial for the downstream of Yangzi River. To understand the level of antibiotic contamination in the large-scale drinking water sources, this study measured antibiotic residues in nine large-scale drinking water sources (five urban drinking water sources and four township drinking water sources) in Chongqing area of the Yangtze River.

Tuning Water Slip Behavior in Nanochannels Using Self-Assembled Monolayers.

Water slip at solid surfaces is important for a wide range of micro-/nanofluidic applications. While it is known that water slip behavior depends on surface functionalization, how it impacts the molecular level dynamics and mass transport at the interface is still not thoroughly understood. In this paper, we use nonequilibrium molecular dynamics simulations to investigate the slip behavior of water confined between gold surfaces functionalized by self-assembled monolayer (SAM) molecules with different polar functional groups.

PFOS, PFOA, estrogen homeostasis, and birth size in Chinese infants.

Laboratory studies have suggested that perfluoroalkyl substances (PFASs) could affect fetal growth by disrupting estrogen homeostasis, but there are limited data for human. For this, 424 mother-infant pairs were selected from a cohort established in Hebei Province of North China in 2013. Two typical PFASs, perfluorooctyl sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA), and three typical estrogens, estrone (E), β-estradiol (E), and estriol (E), were measured in cord serum.

Factors associated with exposure of pregnant women to perfluoroalkyl acids in North China and health risk assessment.

Perfluoroalkyl acids (PFAAs) have been frequently found in blood of pregnant women, but the predictors and potential health risk have not been well studied in China. We recruited 534 pregnant women in Tangshan City of Hebei Province in North China between 2013 and 2014 and measured five PFAAs in serum during their early term of pregnancy, including perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS), perfluorohexane sulfonic acid (PFHxS), perfluoro‑n‑undecanoic acid (PFUdA), and perfluorononanoic acid (PFNA). We explored the factors associated with the levels of serum PFAAs and assessed associated health risks.