The effect of salinity on trimethoprim adsorption by activated sludge extracellular polymeric substances at trace concentration.

The saline wastewater produced in industrial activities and seawater use would flow into wastewater treatment plants and affect the characteristic of extracellular polymeric substance (EPS) of activated sludge, which could potentially impact the removal of antibiotics via adsorption. Nonetheless, the effect of salinity on trimethoprim adsorption by activated sludge extracellular polymeric substances at trace concentration and the underlying mechanism remain largely unknown. In this study, the effect of salinity on the adsorption removal of a typical antibiotic, i.

The erythromycin sorption removal at environmentally relevant concentration based on molecular imprinted polymer: Performance and mechanism.

The antibiotic pollution emerged in different environments has raised a great concern. Adsorption is an effective method to solve the problem. However, conventional adsorbents are not always efficient for antibiotic removal with interferences.

The contradictory roles of tightly bound and loosely bound extracellular polymeric substances of activated sludge in trimethoprim adsorption process.

Extracellular polymeric substances (EPS) of activated sludge are a mixture of high molecular weight polymers secreted by microorganisms, which have the double structure of tightly-bound EPS (TB-EPS) in inner layer and loosely-bound EPS (LB-EPS) in outer layer. The characteristic of LB- and TB-EPS were different, which would affect their adsorption of antibiotics. However, the adsorption process of antibiotics on LB- and TB-EPS was still unclear yet.

Insight into the role of different extracellular polymeric substances components on trimethoprim adsorption by activated sludge.

Adsorption is the primary mechanism of antibiotic removal in wastewater treatment plants, wherein the extracellular polymeric substances (EPS) of the activated sludge play an important role. Due to their complex characteristics, the effect of EPS components on antibiotic adsorption is unknown. Therefore, in this study, the role of main components of EPS in antibiotic adsorption was explored using enzymatic treatment.

Exploring the feasibility of nitrous oxide reduction and polyhydroxyalkanoates production simultaneously by mixed microbial cultures.

Nitrous oxide (NO), as a powerful greenhouse gas, has drawn increasing attention in recent years and different strategies for NO reduction were explored. In this study, a novel strategy for valuable polyhydroxyalkanoates (PHA) production coupling with NO reduction by mixed microbial cultures (MMC) using different substrates was evaluated. Results revealed that NO was an effective electron acceptor for PHA production.

The inhibitory effect of in situ extracellular polymeric substances on trimethoprim adsorption by activated sludge.

The extracellular polymeric substances (EPS) of activated sludge are a mixture of high molecular weight polymers secreted by microorganisms, which are mainly composed of proteins, polysaccharides and humic substances. It is widely accepted that EPS have a good adsorption ability for pollutants with different functional groups. However, recent studies showed the EPS had an inhibitory effect on pollutant sorption, which is contradictory to previous viewpoint.

Lysyl oxidase-like 2 promotes esophageal squamous cell carcinoma cell migration independent of catalytic activity.

Lysyl oxidase-like 2 (LOXL2) is a member of the lysyl oxidase (LOX) family that contributes to tumor cell metastasis. Our previous data identified two splice variants of LOXL2 (i.e.

Quantitatively ranking the influencing factors of ammonia volatilization from paddy soils by grey relational entropy.

Ammonia (NH) volatilization from paddy soils is a main source of atmospheric NH and the magnitude is affected by many factors. Because of the complex field condition, it is difficult to identify the relative importance of individual factor on NH volatilization process in different locations and at different times. In this study, the grey relational entropy method was used to evaluate the relative impact of four main factors (i.

Formation of microbial products by activated sludge in the presence of a metabolic uncoupler o-chlorophenol in long-term operated sequencing batch reactors.

Metabolic uncouplers are widely used for reducing excess sludge in biological wastewater treatment systems. However, the formation of microbial products, such as extracellular polymeric substances, polyhydroxyalkanoate and soluble microbial products by activated sludge in the presence of metabolic uncouplers remains unrevealed. In this study, the impacts of a metabolic uncoupler o-chlorophenol (oCP) on the reduction of activated sludge yield and formation of microbial products in laboratory-scale sequencing batch reactors (SBRs) were evaluated for a long-term operation.

Production of polyhydroxyalkanoates and enrichment of associated microbes in bioreactors fed with rice winery wastewater at various organic loading rates.

This study aimed to explore the production of polyhydroxyalkanoates (PHA) and selection of PHA-accumulating microorganisms in bioreactors fed with rice winery wastewater at various organic loading rates (OLRs). The substrate utilization, sludge properties, PHA synthesis and microbial community structure of three sequencing batch reactors were monitored. The results show the highest PHA yield (0.

Enhanced indirect-to-direct inter-valley scattering in germanium under tensile strain for improving the population of electrons in direct valley.

A theoretical model is proposed to analyze the inter-valley electron transferring between direct Γ and indirect L valleys, which sheds light on the electron conduction dynamics in (0 0 1) tensile strained Ge. Inter-valley scattering is included to calculate average scattering time between Γ and L valleys based on a time-dependent Hamiltonian describing the electron-phonon interaction. Numerical results indicate that enhanced indirect-to-direct inter-valley scattering and reduced direct-to-indirect inter-valley scattering are reliable by introducing tensile strain in Ge material.

A modeling understanding on the phosphorous removal performances of AO and reversed AO processes in a full-scale wastewater treatment plant.

Reversed AO process (anoxic-anaerobic-aerobic) and conventional AO process (anaerobic-anoxic-aerobic) are widely used in many wastewater treatment plants (WWTPs) in Asia. However, at present, there are still no consistent results to figure out which process has better total phosphorous (TP) removal performance and the mechanism for this difference was not clear yet. In this study, the treatment performances of both processes were compared in the same full-scale WWTP and the TP removal dynamics was analyzed by a modeling method.

The enhanced effect of activated sludge attached to the roots of Pistia stratiotes on nutrient removal for secondary effluent.

Aquatic plants are widely used for treating wastewater treatment plant secondary effluent. During this process, some residual activated sludge in the secondary effluent is intercepted and attaches to the plant roots. However, the effect of the attached activated sludge on nutrient removal in secondary effluent has up to now been unknown.

Ezrin Ser66 phosphorylation regulates invasion and metastasis of esophageal squamous cell carcinoma cells by mediating filopodia formation.

Background: Ezrin, links the plasma membrane to the actin cytoskeleton, and plays an important role in the development and progression of human esophageal squamous cell carcinoma (ESCC). However, the roles of ezrin S66 phosphorylation in tumorigenesis of ESCC remain unclear.

Methods: Distribution of ezrin in membrane and cytosol fractions was examined by analysis of detergent-soluble/-insoluble fractions and cytosol/membrane fractionation.

Quantification and kinetic characterization of soluble microbial products from municipal wastewater treatment plants.

Soluble microbial products (SMP) formed by microorganisms in wastewater treatment plants (WWTPs) adversely affect final effluent quality and treatment efficiency. It is difficult to distinguish SMP from residual proteins, lipids and carbohydrates present in the influent that may persist during treatment. No method is currently available to determine quantitatively the extent to which SMP contribute to organic discharges from municipal WWTPs.

Optimizing municipal wastewater treatment plants using an improved multi-objective optimization method.

An improved multi-objective optimization (MOO) model was established and used for simultaneously optimizing the treatment cost and multiple effluent quality indexes (including effluent COD, NH4(+)-N, NO3(-)-N) of a municipal wastewater treatment plant (WWTP). Compared with previous models that were mainly based on the use of fixed decision factors and did not taken into account the treatment cost, this model introduces a relationship model based on back propagation algorithm to determine the set of decision factors according to the expected optimization targets. Thus, a more flexible and precise optimization of the treatment process was allowed.

Evaluating the impact of operational parameters on the formation of soluble microbial products (SMP) by activated sludge.

Soluble microbial products (SMP) are the major component of the residual organic fraction in biological wastewater treatment effluent. The impact of process parameters on SMP production by specific groups of bacteria is currently unknown. In this work, SMP production by activated sludge at different substrate concentrations, dissolved oxygen (DO) levels and temperatures, was evaluated by experimental and modeling approaches.

Characterization of autotrophic and heterotrophic soluble microbial product (SMP) fractions from activated sludge.

Soluble microbial products (SMP) generated by microbial populations can adversely affect the efficiency of biological wastewater treatment systems and secondary effluent quality. In this work, both experimental and modeling approaches were used to investigate the formation of SMP by both heterotrophic and autotrophic bacteria. Strategies to control and reduce SMP in activated sludge systems were thus evaluated.

Formation of distinct soluble microbial products by activated sludge: kinetic analysis and quantitative determination.

Soluble microbial products (SMP) released by microorganisms in bioreactors are classified into two distinct groups according to their different chemical and degradation kinetics: utilization-associated products (UAP) and biomass-associated products (BAP). SMP are responsible for effluent chemical oxygen demand or for membrane fouling of membrane bioreactor. Here an effective and convenient approach, other than the complicated chemical methods or complex models, is developed to quantify the formation of UAP and BAP together with their kinetics in activated sludge process.

Heterotrophs grown on the soluble microbial products (SMP) released by autotrophs are responsible for the nitrogen loss in nitrifying granular sludge.

In this work, nitrogen loss in the nitrite oxidation step of the nitrification process in an aerobic-granule-based reactor was characterized with both experimental and modeling approaches. Experimental results showed that soluble microbial products (SMP) were released from the nitrite-oxidizing granules and were utilized as a carbon source by the heterotrophs for denitrification. This was verified by the fluorescence in situ hybridization (FISH) analysis.

Evaluation on factors influencing the heterotrophic growth on the soluble microbial products of autotrophs.

In this work, the heterotrophic growth on the microbial products of autotrophs and the effecting factors were evaluated with both experimental and modeling approaches. Fluorescence in situ hybridization (FISH) analysis illustrated that ammonia oxidizers (AOB), nitrite oxidizers (NOB), and heterotrophs accounted for about 65%, 20%, and 15% of the total bacteria, respectively. The mathematical evaluation of experimental data reported in literature indicated that heterotrophic growth in nitrifying biofilm (30-50%) and granules (30%) was significantly higher than that of nitrifying sludge (15%).

Formation of soluble microbial products by activated sludge under anoxic conditions.

In this work, both experimental and modeling approaches are used to explore the formation of soluble microbial products (SMP) by activated sludge under anoxic conditions. With substrate consumption, the SMP concentration increases gradually. Utilization associated products (UAP) are the main fraction of SMP when substrate is present; whereas biomass associated products (BAP) are the major content of SMP as substrate is completely consumed.

Microbial and physicochemical characteristics of compact anaerobic ammonium-oxidizing granules in an upflow anaerobic sludge blanket reactor.

Anaerobic ammonium oxidation (anammox) is a promising new process to treat high-strength nitrogenous wastewater. Due to the low growth rate of anaerobic ammonium-oxidizing bacteria, efficient biomass retention is essential for reactor operation. Therefore, we studied the settling ability and community composition of the anaerobic ammonium-oxidizing granules, which were cultivated in an upflow anaerobic sludge blanket (UASB) reactor seeded with aerobic granules.

Fractionating soluble microbial products in the activated sludge process.

Soluble microbial products (SMP) are the pool of organic compounds originating from microbial growth and decay, and are usually the major component of the soluble organic matters in effluents from biological treatment processes. In this work, SMP in activated sludge were characterized, fractionized, and quantified using integrated chemical analysis and mathematical approach. The utilization-associated products (UAP) in SMP, produced in the substrate-utilization process, were found to be carbonaceous compounds with a molecular weight (MW) lower than 290 kDa which were quantified separately from biomass-associated products (BAP).