Effect of electro-stimulated Bacillus subtilis and Lactobacillus casei on ensiling quality, anti-nutrients, and bacterial community of mulberry leaf silage.

Background: There are few studies on the effects of electrically stimulated bacteria on anti-nutritional factors and microbial communities in mulberry leaf silage. This study aimed to examine the impact of the combined use of electrically stimulated Bacillus subtilis (EB) and Lactobacillus casei (LC) on the quality and degradation of anti-nutritional factors in mulberry leaf silage.

Results: The results revealed that the synergistic effect of EB and LC significantly enhanced the nutritional value of mulberry leaves, as evidenced by the promotion of lactic acid synthesis, the reduction of anti-nutritional factors, and the augmentation of lactic acid bacteria following a 60-day silage period.

Electrical stress and acid orange 7 synergistically clear the blockage of electron flow in the methanogenesis of low-strength wastewater.

Energy recovery from low-strength wastewater through anaerobic methanogenesis is constrained by limited substrate availability. The development of efficient methanogenic communities is critical but challenging. Here we develop a strategy to acclimate methanogenic communities using conductive carrier (CC), electrical stress (ES), and Acid Orange 7 (AO7) in a modified biofilter.

Effluent quality prediction of the sewage treatment based on a hybrid neural network model: Comparison and application.

The accurate prediction and assessment of effluent quality in wastewater treatment plants (WWTPs) are paramount for the efficacy of sewage treatment processes. Neural network models have exhibited promise in enhancing prediction accuracy by simulating and analyzing diverse influent parameters. In this study, a back propagation neural network hybrid model based on a tent chaotic map and sparrow search algorithm (Tent_BP_SSA) was developed to predict the effluent quality of sewage treatment processes.

Insight into the mechanism of nutrients removal and response regulation of denitrifying phosphorus removal system under calcium ion stress.

The influent quality is an important factor affecting the nutrients removal and operational stability of denitrifying phosphorus removal (DPR) system. This study investigated the effects of calcium ion (Ca) on the nutrients removal, nitrogen oxide (NO) release, microbial community, and quorum sensing in DPR system. Results showed that high accumulation of Ca had a significant impact on the carbon footprint of DPR system.

Effects of nano metal oxide particles on denitrifying phosphorus removal system: Potential stress mechanism and recovery strategy.

The accumulation of nano metal oxide particles (NMOPs) in municipal sewage treatment systems harms the microbial community and its metabolism in activated sludge system, resulting in the degradation of its pollutants removal performance. In this work, the stress effect of NMOPs on the denitrifying phosphorus removal system was systematically investigated in terms of pollutants removal performance, key enzyme activities, microbial community diversity and abundances, and intracellular metabolites. Among the ZnO NPs, TiO NPs, CeO NPs, and CuO NPs, the ZnO NPs showed the most significant impacts with the chemical oxygen demand, total phosphorus, and nitrate nitrogen removal ratio decreased from above 90 % to 66.

Modeling and optimizing of an actual municipal sewage plant: A comparison of diverse multi-objective optimization methods.

The activated sludge process of an actual municipal sewage treatment plant was systematically modeled, calibrated, and verified in this study. Identified multi-objective optimization (MOO) methods were employed to optimize the process parameters of the validated model, and the optimal MOO algorithm was obtained by comparing Pareto solution sets. The optimization model consisted of three key evaluation indicators (objective functions), which are the average effluent quality (AEQ), overall cost index (OCI), and total volume (TV) of the biochemical tank, along with 12 more process parameters (decision variables).

An integrated process for struvite recovery and nutrient removal from ship domestic sewage.

Marine pollution caused by the untreated and substandard discharge of ship domestic sewage has received widespread attention. A novel integrated process for struvite recovery and nutrient removal from ship domestic sewage (SRNR-SDS) based on seawater magnesium source was developed in this study. Removal efficiencies of the total nitrogen (TN) and total phosphorus (TP) for the activated sludge unit in SRNR-SDS process were approximately 67.

Stability, aggregation, and sedimentation behaviors of typical nano metal oxide particles in aqueous environment.

The wide use of nano metal oxide particles (NMOPs) brings about their inevitable release into the water environment, affecting the environment and human health. Therefore, the stability, aggregation, and sedimentation process of four typical NMOPs (ZnO NPs, CeO NPs, TiO NPs, and CuO NPs) were investigated in artificial water and real municipal sewage to reveal their complicated behavior. Results showed that NMOPs aggregated at the pH of zero-charge point, and their hydrodynamic diameters and aggregation rates could reach the maximum values.

Interactions between bacteria and eukaryotic microorganisms and their response to soil properties and heavy metal exchangeability nearby a coal-fired power plant.

Persistent heavy metal (HM) contaminated soil provides special habitat for microorganisms, HM stress and complex abiotic factors bring great uncertainty for the development of bacteria and eukaryotic microbes. Despite numerous studies about HMs' effect on soil microorganisms, the key factors affecting microbial communities in severe HM contaminated soil and their interactions are still not definite. In this study, the effect of HM fractions and soil properties on the interaction between bacterial communities and eukaryotic microorganisms was studied by high-throughput Illumina sequencing and simplified continuous extraction of HM in severe HM contaminated soil.

Simultaneous denitrification and phosphorus removal: A review on the functional strains and activated sludge processes.

Eutrophication has attracted extensive attention owing to its harmful effects to the organisms and aquatic environment. Studies on the functional microorganisms with the ability of simultaneously nitrogen (N) and phosphorus (P) removal is of great significance for alleviating eutrophication. Thus far, several strains from various genera have been reported to accomplish simultaneous N and P removal, which is primarily observed in Bacillus, Pseudomonas, Paracoccus, and Arthrobacter.

Construction of double tube granular sludge microbial fuel cell and its characteristics and mechanism of azo dye degradation.

Microbial fuel cells (MFCs) can obtain electrical energy from extensive organic matter and complete wastewater treatment at the same time. The principal purpose of the research is to find a solution to the biodegradation of X-3B in a double tube MFC with graphite fiber brush as the anode and carbon cloth as the cathode. The anaerobic, aerobic, and electrochemical processes in the MFC were investigated.

Efficient methane production from waste activated sludge and Fenton-like pretreated rice straw in an integrated bio-electrochemical system.

Integrated microbial electrolysis cell-anaerobic digestion (MEC-AD) systems have demonstrated potential advantages for methane production in the presence of small amounts of residual inhibitors. In this study, a series of tests were conducted to analyse the acidification and methanogenesis performance of pretreated rice straw (RS) in anaerobic digestion (AD) and MEC-AD systems after the addition of Fenton-like reagents. The results indicated that the short-chain acids (SCFAs) accumulations reached 2284.

Interactions between cerium dioxide nanoparticles and humic acid: Influence of light intensities and molecular weight fractions.

Cerium dioxide nanoparticles (CeO NPs) are ubiquitous in the water environment due to the extensive commercial applications. The complexity of heterogeneous humic acid (HA) plays a significant role in affecting the physicochemical properties of CeO NPs in aqueous environments. However, the effects of light intensities and HA fractions on the interaction mechanism between CeO NPs and HA are poorly understood.

Aggregation behavior of zinc oxide nanoparticles and their biotoxicity to Daphnia magna: Influence of humic acid and sodium alginate.

The widespread applications of zinc oxide nanoparticles (ZnO NPs) have raised increasing concerns due to their adverse environmental effects. The ubiquitous natural organic matter in natural aqueous environments can interact with ZnO NPs, thereby affecting their aggregation, sedimentation and biotoxicity. Here, we systematically investigated the effects of humic acid (HA) and sodium alginate (SA) on the aggregation behavior of ZnO NPs and their biotoxicity to Daphnia magna.

Methane production in a bioelectrochemistry integrated anaerobic reactor with layered nickel foam electrodes.

Towards the regulation and enhancement of inter-species electron transfer in sludge anaerobic digestion system, microbial electrolysis technology has become one of the effective ways to accelerate both fermentation and methanogenesis. In this study, the reactor performances and microbial activities related to biocathode formation are evaluated when the role of biocathode is regulated by series of layered cathodes. The results show the abundance of the cathodic methanogens decreased when enlarges the cathode area due to the lower current density.

Alkaline aided thermophiles pretreatment of waste activated sludge to increase short chain fatty acids production: Microbial community evolution by alkaline on hydrolysis and fermentation.

Adding alkaline into an anaerobic waste activated sludge (WAS) fermentation with thermophilic bacteria pretreatment could efficiently improve short-chain fatty acids (SCFAs) accumulation to 3550 ± 120 mg COD/L. The acidification rate in combined test was 21.2%, while that was 15.

Potassium ferrate addition as an alternative pre-treatment to enhance short-chain fatty acids production from waste activated sludge.

A potentially practical technology based on ferrate (VI), i.e. potassium ferrate (PF), pretreatment integrated into waste activated sludge (WAS) anaerobic fermentation has been presented to greatly enhance short-chain fatty acids (SCFAs) production with a shortened fermentation time.

Computational and experimental analysis of organic degradation positively regulated by bioelectrochemistry in an anaerobic bioreactor system.

Methane production was tested in membrane-less microbial electrolysis cells (MECs) under closed-circuit (R) and open-circuit (R) conditions, using glucose as a substrate, to understand the regulatory effects of bioelectrochemistry in anaerobic digestion systems. A dynamic model was built to simulate methane productions and microbial dynamics of functional populations, which were colonized in groups R and R during the start-up stage. The experiment results showed significantly greater methane production in R than R, the average methane production of R was 0.

Clarification of phosphorus fractions and phosphorus release enhancement mechanism related to pH during waste activated sludge treatment.

This study aimed to clarify phosphorus (P) fractions in waste activated sludge (WAS) and explore release performance and enhancement mechanism of different P species related to pH. Results showed that inorganic P (IP) was the major P fraction in raw sludge (87.86% of total solid P), and non-apatite inorganic P (NAIP), the most labile P forms, occupied 81.

Lignocellulosic saccharification by a newly isolated bacterium, Ruminiclostridium thermocellum M3 and cellular cellulase activities for high ratio of glucose to cellobiose.

Background: Lignocellulosic biomass is one of earth's most abundant resources, and it has great potential for biofuel production because it is renewable and has carbon-neutral characteristics. Lignocellulose is mainly composed of carbohydrate polymers (cellulose and hemicellulose), which contain approximately 75 % fermentable sugars for biofuel fermentation. However, saccharification by cellulases is always the main bottleneck for commercialization.

Microbial network for waste activated sludge cascade utilization in an integrated system of microbial electrolysis and anaerobic fermentation.

Background: Bioelectrochemical systems have been considered a promising novel technology that shows an enhanced energy recovery, as well as generation of value-added products. A number of recent studies suggested that an enhancement of carbon conversion and biogas production can be achieved in an integrated system of microbial electrolysis cell (MEC) and anaerobic digestion (AD) for waste activated sludge (WAS). Microbial communities in integrated system would build a thorough energetic and metabolic interaction network regarding fermentation communities and electrode respiring communities.