Attachment Of Microorganisms Research Articles

Root and rhizome traits of the common reed (Phragmites australis) in a constructed wetland for wastewater treatment

Belowground plant parts play an important role in wetland functioning but their biomass and structural traits have remained out of focus in constructed wetlands. We studied the biomass and structural traits of rhizomes and roots of Phragmites australis (Cav.) Steud. in the inflow and outflow parts of a newly established constructed wetland with subsurface horizontal flow (Slavošovice, Czech Republic). The rhizome biomass of P. australis increased until the 6th year after planting and reached about 1.5 and 2.0 kg.m−2 in the inflow and outflow parts of the bed, respectively. The average live root biomass was about 7% of the total live belowground biomass. Analysis of the rhizome branching pattern showed that in the 8th year after planting, the rhizome life span was definitely two years and most probably up to four years. The root structural traits showed that thicker and shorter roots were formed in the inflow part. As a result, there were differences in total root length, which reached 2.4 km m−2 in the inflow and 3.3 km m−2 in the outflow parts. This probably reflects a higher nutrient availability at the inflow rather than the toxicity of the discharged wastewater. The results of this study support previous arguments that the belowground parts of P. australis are an important carbon source in constructed wetlands, tolerate the anaerobic environment in the treatment bed well and provide a large surface area for the attachment of microorganisms.

3D Hierarchical Co8FeS8-FeCo2O4/N-CNTs@CF with an Enhanced Microorganisms-Anode Interface for Improving Microbial Fuel Cell Performance.

Microbial fuel cells (MFCs) are promising ecofriendly techniques for harvesting bioenergy from organic and inorganic matter. Currently, it is challenging to design MFC anodes with favorable microorganism attachment and fast extracellular electron transfer (EET) rate for high MFC performance. Here we prepared N-doped carbon nanotubes (NCNTs) on carbon felt (CF) and used it as a support for growing hierarchical Co8FeS8-FeCo2O4/NCNTs core-shell nanostructures (FeCo/NCNTs@CF). We observed improved wettability, specific areal capacitance, and diffusion coefficient, as well as small charge transfer resistance compared with bare CF. MFCs equipped with FeCo/NCNTs@CF displayed a power density of 3.04 W/m2 and COD removal amount of 221.0 mg/L/d, about 47.6 and 290.1% improvements compared with that of CF. Biofilm morphology and 16s rRNA gene sequence analysis proved that our anode facilitated the enrichment growth of exoelectrogens. Flavin secretion was also promoted on our hierarchical elelctrode, effectively driving the EET process. This work disclosed that hierarchical nanomaterials modified electrode with tailored physicochemical properties is a promising platform to simultaneously enhance exoelectrogen attachment and EET efficiency for MFCs.

Extracellular Polymeric Substances and Biocorrosion/Biofouling: Recent Advances and Future Perspectives.

Microbial cells secrete extracellular polymeric substances (EPS) to adhere to material surfaces, if they get in contact with solid materials such as metals. After phase equilibrium, microorganisms can adhere firmly to the metal surfaces causing metal dissolution and corrosion. Attachment and adhesion of microorganisms via EPS increase the possibility and the rate of metal corrosion. Many components of EPS are electrochemical and redox active, making them closely related to metal corrosion. Functional groups in EPS have specific adsorption ability, causing them to play a key role in biocorrosion. This review emphasizes EPS properties related to metal corrosion and protection and the underlying microbially influenced corrosion (MIC) mechanisms. Future perspectives regarding a comprehensive study of MIC mechanisms and green methodologies for corrosion protection are provided.

Development of Orthodontic Resin with Antibacterial Property against Biofilm of Respiratory Pathogens

Orthodontic appliance made of resin is one of the main factors involving the shift of oral microbial community towards the source of pathogens by providing an extra site for adhesion and attachment of microorganisms to form biofilm associated with infections of multiple organs including respiratory tract. As a result, there is a demand for seeking of oral appliances with antimicrobial properties to reduce the risk of these infections. Here, vanillin (a principal flavoring agent with its antimicrobial property) has been incorporated to orthodontic resin and investigated the effect on biofilm formation of respiratory pathogens. The self-curing PMMA orthodontic resin samples (Siam Cement Group, Thailand) were fabricated depending on the percentage of vanillin adding (0.1% and 0.5% w/w vanillin). Resin without vanillin was used as a control. All samples were coated with sterile saliva collected from healthy volunteers. The bacterial biofilm formation assay was done by adding suspension (107 colony forming unit/mL) of Staphylococcus aureus ATCC 5638, Staphylococcus epidermidis ATCC 14990, Streptococcus pneumoniae ATCC 49619, and Pseudomonas aeruginosa ATCC 27853 to the samples and incubated in shaking incubator (120 r/min) for 120 min at 37 °C to allow the adhesion of the bacteria. Afterwards, non-adherent bacterial cells were washed out and Brain Heart Infusion broth was added and further incubated for 24 h to enable the biofilm formation. The amount of vital biofilm was quantified by Cell Counting Kit WST-8 (Dojindo Molecular Technologies, USA). It was found that the inclusion of vanillin to resin decreased the biofilm formation of S. aureus, S. epidermidis, and P. aeruginosa whereas no effect was observed on S. pneumoniae. Both the 0.1% and 0.5% vanillin concentrations could significantly inhibit the biofilm of S. aureus and P. aeruginosa whereas only 0.5% vanillin showed the inhibitory effect on S. epidermidis. Up to 40% biofilm reduction was noticed with S. epidermidis and P. aeruginosa while that of S. aureus was about 30%. In conclusion, the present data demonstrate that the development of orthodontic PMMA resin incorporated with vanillin may be a possible candidate for fabricating of oral appliance with antimicrobial property against respiratory pathogens. This suggests that it could be useful for the prevention or management of respiratory infection related to bacterial biofilm formed on oral appliances.

Thermal Spray Coatings for Protection Against Microbiologically Induced Corrosion: Recent Advances and Future Perspectives

Corrosion has been persisting as the most severe concern for steel structures in the marine environment. Due to the widespread occurrence of biofouling, apart from the electrochemical corrosion, microbiologically induced corrosion (MIC) is an important factor that triggers the deterioration of marine steel infrastructures. Traditional anti-corrosion coatings usually lack the antifouling function, attachment and colonization of marine microorganisms therefore in most cases accelerate the existing corrosion damage. Anti-corrosive coating fabricated by thermal spray has been extensively applied for the marine corrosion prevention, yet the anti-MIC coatings deposited by thermal spray technical route still keep elusive. Developing thermal-sprayed coatings with dual anti-corrosion and antifouling performances is the key to combating MIC. In this review, most recent advances in understanding biofouling and developing antifouling and anti-MIC techniques are surveyed. The formation and evolution of MIC and biofouling, and the effect of microbial biofilm on their occurrence are addressed briefly. Strategies involving the use of chemical methods, physical methods and biological methods to prevent MIC and biofouling are discussed. Selection and design of thermal spray coating materials with desired corrosion resistance and antifouling performances are reviewed. Current perspectives and future possibilities of thermal-sprayed marine coatings for long-term anti-MIC applications are also discussed.

A new modification method of metal substrates via candle soot to prepare effective anodes in air‐cathode microbial fuel cells

AbstractBACKGROUNDChoosing applicable anodes can effectively promote the performance of microbial fuel cells (MFCs). This study introduced a novel method to prepare effective metal‐based anodes modified by carbon nanoparticles (CNPs) derived from candle soot. The CNPs can be firmly coated on the metal and the modified metal surfaces show good hydrophilicity.RESULTSThis study used titanium mesh, stainless steel sheet and copper sheet as the anode's substrate, respectively. CNPs could improve the biocompatibility and electrochemical properties of these metals. The power generation performance of MFCs with CNP‐modified anodes has been dramatically enhanced, and the maximum power density is 616 mW m−2 in MFCs with CNP‐modified titanium mesh anode.CONCLUSIONAfter CNP modification, the rough surface and excellent biocompatibility could promote the attachment and growth of microorganisms, which may be the main reasons for the improvement of MFC performance. Besides, this method is suitable to modify different metal substrates. The results showed that the CNP‐coated metal anodes could improve the power output of MFCs compared to pure metal anodes. Therefore, this method has significant advantages in the practical application of MFCs. © 2021 Society of Chemical Industry (SCI).

Treatment of Dye Waste Water using Moving Bed Biofilm Reactor and Granular Activated Carbon with Neem Leaf Powder

In recent days, the waste productions from industries are increased and direct discharge of wastes causes various pollution to the environment. Wastewater treatment in textile and dye industry mainly involves treatment of highly colored wastewater containing variety of dyes in different concentrations. The dyeing industries using different types of pigments and dyes of various concentration during their several production steps. These industries discharge a wastewater which contains organic substance, high colour with high COD and low concentration of BOD. This dye waste water are directly discharge in to the streams and thus contaminate the groundwater. To treat the wastewater, which is discharge from the dyeing industries a simple physio-chemical treatment is not sufficient for the removal of pollutants. So that a biological treatment followed with a physio-chemical treatment have been required. In this study, the experiment was carried out to reduce the organic substance, high colour, COD, BOD, and Heavy metals from dye wastewater using the laboratory scale Moving Bed Biofilm Reactor followed with Granular activated Carbon bed (GAC with NLP-MBBR) with Neem leaf powder. A various thick granular activated carbon bed was used for adsorption technique and for biological treatment of wastewater. The GAC with 8cm thick is layered followed by Ennore sand with 3 grades with 4cm thick equally. Then the MBBR was operated continuously with various retention times. The polypropylene type bio balls were used for microorganism attachment in MBBR. The outlet water from the MBBR are treated using membrane process. Membrane process using moving membranes reduces the pH, organic contents, heavy metals, COD, BOD, turbidity etc., The final effluent water is suitable for Irrigation.

Fabrication of Porous Aluminum Coating by Cored Wire Arc Spray for Anchoring Antifouling Hydrogel Layer.

Biofouling has been persisting as a worldwide problem due to the difficulties in finding efficient environment-friendly antifouling coatings for long-term applications. Developing novel coatings with desired antifouling properties has been one of the research goals for surface coating community. Recently hydrogel coating was proposed to serve as antifouling layer, for it offers the advantages of the ease of incorporating green biocides, and resisting attachment of microorganisms by its soft surface. Yet poor adhesion of the hydrogel on steel surfaces is a big concern. In this study, porous matrix aluminum coatings were fabricated by cored wire arc spray, and the sizes of the pores in the aluminum (Al) coatings were controlled by altering the size of the cored powder of sodium chloride. Silicone hydrogel was further deposited on the porous coating. The hydrogel penetrated into the open pores of the porous Al coatings, and the porous Al structure significantly enhanced the adhesion of the hydrogel. In addition, hydrogel coating exhibited very encouraging antifouling properties.

Coupling room-temperature phosphorescence carbon dots onto active layer for highly efficient photodynamic antibacterial chemotherapy and enhanced membrane properties

Biofouling has become a concerning issue in developing thin-film composite (TFC) forward osmosis (FO) membranes. The attachment of microorganisms onto the TFC FO membrane surface seriously influenced the membrane life span, resulting in the increased operation and maintenance costs. Herein, room-temperature phosphorescence (RTP) carbon dots using isophthalic acid (IPA) as a carbon source (IPA-C-dots) and nanocomposites by conjugation of IPA-C-dots with polylysine (PLL) (IPA-C-dots/PLL) were synthesized. The TFC FO membranes were coupled with nothing, PLL and IPA-C-dots/PLL to prepare control membrane (Control-M), PLL one (PLL-M), and IPA-C-dots/PLL one (IPA-C-dots/PLL-M), respectively. Due to the excellent hydrophilicity and smoothness of the membrane surface, the IPA-C-dots/PLL-M shows much higher water permeability, lower structural parameter, and acceptable salt rejection, resulting in enhanced membrane properties. What is more, the static and dynamic bio-fouling resistant tests indicate IPA-C-dots/PLL-M possesses a significant anti-biofouling property. The reason for this observation lay in the coupled IPA-C-dots can generate singlet oxygen (1O2) through energy transfer from excited triplet state to dissolved triplet oxygen under light irradiation, which can be served as a photodynamic antibacterial chemotherapy reagent, bettering the biofouling resistance properties. The conjugation of RTP C-dots onto TFC FO membranes opened up a promising door for the high efficient inhibition of bacterial proliferation and the enhancement of membrane properties.

Low concentration of Tween-20 enhanced the adhesion and biofilm formation of Acidianus manzaensis YN-25 on chalcopyrite surface

Although Tween-20 was used as an important catalyst to increase chalcopyrite bioleaching rate by acidophiles, the effect of Tween-20 on initial adhesion and biofilm development of acidophiles on chalcopyrite has not been explored until now. Herein, the role of Tween-20 in early attachment behaviors and biofilm development by Acidianus manzaensis strain YN-25 were investigated by adhesion experiments, adhesion force measurement, visualization of biofilm assays and a series of analyses including extended Derjaguin Landau Verwey Overbeek (DLVO) theory, scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The bacterial adhesion experiments showed that 2 mg/L of Tween-20 increased the adhesion percentage (by 8%) of A. manzaensis YN-25. Tween-20 could promote the early adhesion of A. manzaensis YN-25 by changing the Lewis acid-base interaction and electrostatic force to increase total interaction energy and adhesion force. Besides, the functional groups on the surface of cells (carboxyl, hydroxyl and amino functional groups) contributed to the adhesion of A. manzaensis YN-25 on chalcopyrite. Furthermore, the promotion of biofilm formation by Tween-20 was mainly attributed to the reduction of S0 passivation layer formation and complexing more Fe3+ on chalcopyrite surface, contributing to the erosion of chalcopyrite and creating more corrosion pits. Live/dead staining showed low live/dead ratio (ranged from 0.35 to 1.32) during the biofilm development process. This report offers a better understanding of the effects of Tween-20 on attachment and biofilm development of acidophilic microorganisms and would lay a theoretical foundation for the better application of catalyst in bioleaching.

Influence mechanism of filling ratio on solid-phase denitrification with polycaprolactone as biofilm carrier

In this study, three up-flow fixed-bed bioreactors were constructed with three different filling ratios (filling volume/effective volume: 30%, 60% and 90%) of polycaprolactone (PCL). Above 98% of nitrate removal efficiency was achieved with low accumulations of nitrite and ammonium for each filling ratio. Low filling ratio of PCL had extensive folds and pores that favored the attachment and growth of microorganisms; however, excessive biomass restrained nitrate specific reduction rate (NaSRR). The most dominant genera were Comamonas (0.80–57.64%), Stenotrophomonas (2.59–54.39%), Acidovorax (7.32–23.55%), Allorhizobium-Neorhizobium-Pararhizobium-Rhizobium (0.30–19.74%) and Thermomonas (0.12–14.58%). Nitrate reductase (EC 1.7.99.4), nitrite reductase (EC 1.7.2.1) and nitric oxide reductase (EC 1.7.2.5) predicted by PICRUSt2 were abundant in high influent nitrate load (NaL). According to the analysis of carbon balance model, the utilization rate (η) of PCL showed a highly positive correlation with influent NaL, indicating reducing filling ratio or HRT might be an effective measure to save cost for nitrate removal.

Injectable Self-Healing Hydrogel via Biological Environment-Adaptive Supramolecular Assembly for Gastric Perforation Healing.

Developing effective internal wound dressing materials is important for postoperative tissue regeneration while remains a challenge due to the poor biological environment-adaptability of conventional materials. Here, we report an example of injectable self-healing hydrogel based on gastric environment-adaptive supramolecular assembly, and have explored its application for gastric perforation healing. By leveraging the gastric environment-modulated supramolecular interactions, the self-assembled hydrogel network is orchestrated with sensitive thermo-responsibility, injectability, printability and rapid self-healing capability. The hydrogel dressing can effectively inhibit the attachment of microorganisms and demonstrates outstanding antibiofouling property. In vivo rat model further demonstrates the as-prepared hydrogel dressing simplifies the surgical procedures, reduces postoperative complications as well as enhances the healing process of gastric perforation compared with the conventional treatment. This work provides useful insights into the development of biological environment-adaptive functional materials for various biomedical applications.

Modelling formation and removal of biofilms in secondary dairy raw materials

Introduction. Microorganisms of dairy raw materials tend to adhere to the surfaces of processing equipment and form sustainable biofilms, which is a serious issue in the dairy industry. The goal of the present work was to investigate formation of biofilms on a glass surface in static model conditions, and removal of such biofilms by cleaning.
 Study objects and methods. The study objects were the permeates of skim milk, sweet whey and acid whey, as well as the biofilms formed and washings from glass slides. Biofilms were removed from the glass with detergents used in the dairy industry. Standard methods of determining microbiological and physicochemical properties were used to characterize the permeates. The biofilm structure and morphology of microorganisms participating in biofilm formation were investigated with a light spectroscopy. The efficiency of biofilm removal in a cleaning process was quantified with optical density of washings.
 Results and discussion. Biofilms in whey permeates formed slower compared to those in skimmed milk permeate during the first 24 h. Yeasts contributed significantly to the biofilm microflora in acid whey permeate throughout 5 days of biofilm growth. Well adhered biofilm layers were the most stable in skimmed milk permeate. The highest growth of both well and poorly adhered biofilm layers was observed in sweet whey permeate after 3–5 days. It was established that the primary attachment of microorganisms to a glass surface occurred within 8 h, mature multicultural biofilms formed within 48 h, and their partial destruction occurred within 72 h.
 Conclusion. The research results can be used to improve the cleaning equipment procedures in processing secondary dairy raw materials.

Understanding microbial infections using microarray technology

Human microbial infections are symbiotic processes between pathogens and humans that often lead to human disease and death. Microbial infections involve the attachment, growth, and survival of microorganisms on human skin, inside the body, or inside specific cells. Microbial infections can be localized to one body region or migrate to secondary body locations utilizing various transport mechanisms. Understanding host-pathogen interactions related to the expression of essential genes during and after infection can lead to valuable information for biologists and clinicians. Microarray technologies allow researchers to perform genomic characterization experiments rapidly and efficiently. Microarray experiments support the resolution of underlying molecular events that play a role in normal and aberrant physiologic activities in living systems. Microarray technology, coupled with bioinformatics analysis, generates comprehensive insights into relevant genes, proteins, and protein-protein interactions. This review article explores recent microarray research studies from select protozoan and bacterial pathogens to illustrate how researchers utilize microarray technology to examine microbial infection aspects. Microarray studies of pathogen and host genomes at various stages of the infection process will generate a more precise understanding of pathogenic life cycles and pathogen survival strategies. Detailed knowledge of the genes involved in the microbial infection process will lead to discovering disease biomarkers and potent therapeutic solutions.

Bacterial Cellulose from Food to Biomedical Products

Cellulose production of aerobic bacteria with its very unique physiochemical properties attracted many researchers. The biosynthetic of Bacterial Cellulose (BC) was produced by low-cost media recently. BC has been used as biomaterials and food ingredient these days. Moreover, the capacity of BC composite gives the numerous application opportunities in other fields. Bacterial Cellulose (BC) development is differentiated from suspension planktonic culture by their Extracellular Polymeric Substances (EPS), down-regulation of growth rate and up-down the expression of genes. The attachment of microorganisms is highly dependent on their cell membrane structures and growth medium. This is a very complicated phenomenon that optimal conditions defined the specific architecture. This architecture is made of microbial cells and EPS. Cell growth and cell communication mechanisms effect biofilm development and detachment. Understandings of development and architecture mechanisms and control strategies have a great impact on the management of BC formation with beneficial microorganisms. This mini-review paper presents the overview of outstanding findings from isolating and characterizing the diversity of bacteria to BC's future application, from food to biosensor products. The review would help future researchers in the sustainable production of BC, applications advantages and opportunities in food industry, biomaterial and biomedicine.

Pseudomonas putida as a potential biocontrol agent against Salmonella Java biofilm formation in the drinking water system of broiler houses

BackgroundEnvironmental biofilms can induce attachment and protection of other microorganisms including pathogens, but can also prevent them from invasion and colonization. This opens the possibility for so-called biocontrol strategies, wherein microorganisms are applied to control the presence of other microbes. The potential for both positive and negative interactions between microbes, however, raises the need for in depth characterization of the sociobiology of candidate biocontrol agents (BCAs). The inside of the drinking water system (DWS) of broiler houses is an interesting niche to apply BCAs, because contamination of these systems with pathogens plays an important role in the infection of broiler chickens and consequently humans. In this study, Pseudomonas putida, which is part of the natural microbiota in the DWS of broiler houses, was evaluated as BCA against the broiler pathogen Salmonella Java.ResultsTo study the interaction between these species, an in vitro model was developed simulating biofilm formation in the drinking water system of broilers. Dual-species biofilms of P. putida strains P1, P2, and P3 with S. Java were characterized by competitive interactions, independent of P. putida strain, S. Java inoculum density and application order. When equal inocula of S. Java and P. putida strains P1 or P3 were simultaneously applied, the interaction was characterized by mutual inhibition, whereas P. putida strain P2 showed an exploitation of S. Java. Lowering the inoculum density of S. Java changed the interaction with P. putida strain P3 also into an exploitation of S. Java. A further increase in S. Java inhibition was established by P. putida strain P3 forming a mature biofilm before applying S. Java.ConclusionsThis study provides the first results showing the potential of P. putida as BCA against S. Java in the broiler environment. Future work should include more complex microbial communities residing in the DWS, additional Salmonella strains as well as chemicals typically used to clean and disinfect the system.

In situ modelling of biofilm formation in a hydrothermal spring cave

Attachment of microorganisms to natural or artificial surfaces and the development of biofilms are complex processes which can be influenced by several factors. Nevertheless, our knowledge on biofilm formation in karstic environment is quite incomplete. The present study aimed to examine biofilm development for a year under controlled conditions in quasi-stagnant water of a hydrothermal spring cave located in the Buda Thermal Karst System (Hungary). Using a model system, we investigated how the structure of the biofilm is formed from the water and also how the growth rate of biofilm development takes place in this environment. Besides scanning electron microscopy, next-generation DNA sequencing was used to reveal the characteristic taxa and major shifts in the composition of the bacterial communities. Dynamic temporal changes were observed in the structure of bacterial communities. Bacterial richness and diversity increased during the biofilm formation, and 9–12 weeks were needed for the maturation. Increasing EPS production was also observed from the 9–12 weeks. The biofilm was different from the water that filled the cave pool, in terms of the taxonomic composition and metabolic potential of microorganisms. In these karstic environments, the formation of mature biofilm appears to take place relatively quickly, in a few months.

Ancillary palm oil fuel ash (POFA) in sequencing batch reactor for enhancing recalcitrant pollutants removal from domestic wastewater

Domestic wastewater has been generated massively along with rapid growth of population and economic. Biological treatment using sequencing batch reactor (SBR) augmented with palm oil fuel ash (POFA) was investigated for the first time. The performance of POFA in enhancing biological treatment of wastewater has not been tested. The porosity property of POFA can improve SBR efficiency by promoting growth of mixed liquor suspended solids (MLSS) and formation of larger flocs for settling and facilitating attachment of microorganisms and pollutants onto POFA surfaces. The properties of POFA were tested to identify morphological properties, particle size, surface area, chemical compositions. Four SBRs, namely SBR1, SBR2, SBR3 and SBR4 were provided with aeration rate of 1, 2, 3 and 4 L/min, respectively. Each reactor was augmented with different dosages of POFA. Optimum aeration rate and POFA concentration were identified by the performance of SBRs in removing chemical oxygen demand (COD), ammoniacal nitrogen (NH3–N) and colour from domestic wastewater. The results showed the most efficient COD (97.8%), NH3–N (99.4%) and colour (98.8%) removals were achieved at optimum POFA concentration of 4 g/L in SBR and aeration rate of 1 L/min. The study also found that higher aeration rate would contribute to the smaller specific size of flocs and decrease the pollutant removal efficiency.

An integrated green methodology for the continuous biological removal and fixation of arsenic from acid wastewater through the GAC-catalyzed As(III) oxidation

Herein we report the findings of an integrated green process for the continuous oxidation and biomineralization of the most toxic As(III) from acidic streams using a laboratory-scale airlift bioreactor operated at thermoacidophilic conditions and fed with Fe(II) as electron donor. As(III) oxidation catalyzed by granular activated carbon (GAC), biological Fe(II) oxidation and scorodite crystallization took place simultaneously in the reactor, allowing the treatment of influent solutions containing 0.65 g·L−1 As(III). At a hydraulic retention time of 2.2 days, a stable arsenite oxidation efficiency of 99% was achieved, while the removal of total arsenic was 93%. Scorodite was yielded as the main solid product whose physical characteristics such as average size (250 µm) and the developed crystalline structure allowed the easy harvesting from the reactor and reflected the high stability by the low arsenic release of 0.4 mg.L−1 after 60 days of leaching. The analysis of the microbial composition in the reactor suspension and the precipitates indicated the dominance of thermoacidophilic archaeon of the genus Acidianus. Similarly, the attachment of microorganisms to the precipitates observed by scanning electron microscopy, suggested that the precipitation in our system was biologically mediated. The simultaneous arsenic oxidation and removal through catalyzed oxidation and biological processes provide the basis for a new and cost effective green methodology for arsenic fixation from acid As(III)-containing wastewaters.

Higher nitrogen removal achieved in constructed wetland with polyethylene fillers and NaOH-heating pre-treated corn stalks for advanced treatment of low C/N sewage.

Advanced processing of low C/N sewage faces the carbon sources shortage, while quantities of agricultural biomass wastes need to be disposed. This study investigated the potential of quantitative modified biomass addition in constructed wetlands (CWs) filled with polyethylene fillers. Results showed that the lignin in NaOH-heating pretreated corn stalks (NH-CSs) was destroyed, and the wrinkles on the stalks increased and became more soft after pretreatment, which was more conducive to the utilization of carbon sources and attachment of microorganisms. Compared with glucose and sodium acetate, the denitrification with mixed carbon source (glucose and NH-CSs) had the highest effective utilization percentage (61.37%) and NH-CSs were expected to become stable and fast-release carbon sources. After adding 30g NH-CSs to the rear unit of CW with polyethylene fillers (CW-A), TN removal efficiency was increased by 18.21%, and the average removal efficiency of COD, NH4+-N, TN, and TP reached 54.83%, 89.95%, 64.11%, and 45.04%, respectively. Compared with the traditional CW (CW-B), CW-A had a significant denitrification advantage (P < 0.05), but the removal efficiency and effluent stability of phosphorus were inferior to CW-B. These results indicate that the biomass carbon sources such as corn stalks and polyethylene fillers have a good potential to improve the denitrification in CWs.