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Optimization of synthetic domestic wastewater treatment performance in anoxic/aerobic sequencing batch reactor with zeolite addition

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JOURNAL OF ENVIRONMENTAL ScIENcE AND HEALTH PART A-TOXIc/HAZARDOUS SUBSTANcES & ENVIRONMENTAL ENGINEERING 2023年第6期58卷 525-537页

作者： Gurtekin, Engin Firat Univ Dept Environm Engn Elazig Turkiye

In this study, treatment performance was investigated based on chemical oxygen demand (cOD), ammonium nitrogen (NH4+-N), total inorganic nitrogen (TIN) and simultaneous nitrification and denitrification (SND) parameters in a zeolite-added anoxic/aerobic sequencing batch reactor. Response surface methodology (RSM) was used to model treatment performance, determine the impact of operating conditions, and optimize them. The effect of zeolite size, dosage and cOD/NH4+-N (c/N) ratio as operating parameters were evaluated in the central composite design (ccD). Variance analysis (ANOVA) results of the quadratic model, high coefficients of determination and low values of the root mean square error (RMSE) for dependent variables indicated the validity of the model in predicting experimental results. The desirability function showed that optimum conditions were 0.80 mm for zeolite size, 3.05 g/L for zeolite dosage and 9.8 for c/N. Under these conditions, the maximum cOD, NH4+-N, TIN removal efficiencies and SND efficiency were 92.85%, 93.3%, 77.33% and 82.96%, respectively. The results of the study showed that the most effective independent variable on dependent variables was the c/N ratio.

关键词： Anoxic aerobic c N ratio response surface methodology (RSM) simultaneous nitrification and denitrification (SND) zeolite

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corrosion Behavior of Mg-Zn-RE Alloys (RE = Gd, Y, Nd)

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JOURNAL OF MATERIALS ENGINEERING AND PERFORMANcE 2023年第6期32卷 2840-2852页

作者： Kumar, Arun S. Rajesh, K. R. Jayaraj, Jithu Raghu, K. G. Srinivasan, A. CSIR Natl Inst Interdisciplinary Sci & Technol Thiruvananthapuram 695019 Kerala India Acad Sci & Innovat Res AcSIR Ghaziabad 201002 India

The effect of different rare earth elements (Gd, Y, Nd) with similar atomic percentage on the corrosion behavior of Mg-1.52Zn (at.%) was investigated. The secondary phases and corrosion film formed on the surface of the alloys during immersion in aqueous Nacl solution affects the corrosion behavior of the alloy. The electrochemical, weight loss and hydrogen evolution tests revealed that corrosion rate of Mg-1.52Zn-0.15Gd was the highest and the corrosion rate of other three alloys were almost similar. The discrete second phases in Mg-1.52Zn-0.15Gd acted as severe cathodes to the matrix and accelerated the micro-galvanic corrosion whereas network shaped and uniformly distributed phases in Mg-1.52Zn-0.15Nd alloy effectively retarded corrosion. The immediate formation of Nd2O3 in the corrosion film of Mg-1.52Zn-0.15Nd alloy also contributed in improved corrosion resistance. Dominant presence of Y2O3 in Mg-1.52Zn-0.16Yalloy contributed to its better corrosion resistance.

关键词： B magnesium c rare earths corrosion

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Principles for quorum sensing-based exogeneous denitrifier enhancement of nitrogen removal in biofilm: a review

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cRITIcAL REVIEWS IN ENVIRONMENTAL ScIENcE AND TEcHNOLOGY 2023年第14期53卷 1404-1429页

作者： Zhu, Ying-nan Wang, Jinfeng Liu, Qiuju Jin, Ying Ding, Lili Ren, Hongqiang Nanjing Univ Sch Environm State Key Lab Pollut Control & Resource Reuse Nanjing Peoples R China

Denitrifying bacteria play critical roles in enhancing biological biofilm denitrification for nitrogen removal in industrial and municipal wastewater treatment and groundwater remediation. Evidence intensively confirms that exogenous quorum sensing (QS) bacteria prompt biofilm formation and denitrification. Yet, exogenous bacteria forfeiting during bioaugmentation may occur despite of its priority effect and improved community function, because of open, intricate traits in wastewater treatment system. critical topics include regulating signal-based microecological structure, effectively assembling 3D biofilm, and regulating carbon and nitrogen metabolization of denitrifiers to reduce cO2 and N2O emissions. This review demonstrates classifications of denitrifiers and the vital role of QS in regulating biofilm denitrification. Furthermore, the ecological principles of microbial community construction with the addition of exogenous denitrifiers are summarized. Moreover, the effects of signaling molecules on carbon and nitrogen transcription and metabolization are discussed. In conclusion, technologies based on quorum sensing for enhanced denitrification have high application potential and challenges. Herein, we provide a guideline for enhancing nitrogen removal by exogenous quorum-sensing bacteria and synthetic biofilms design during upgrading of municipal wastewater treatment plants.

关键词： Quorum sensing (QS) AHLs denitrifying bacteria regulation of carbon and nitrogen metabolism c N Eakalak Khan and Lena Q Ma

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Effects of Zn injection into boric acid and lithium hydroxide solutions on the corrosion behaviors of 316LN stainless steel in simulated hot functional test high-temperature pressurized water

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cORROSION ScIENcE 2023年第1期215卷

作者： Peng, Liyuan Zhang, Ziyu Tan, Jibo Wu, Xinqiang Chinese Acad Sci Inst Met Res CAS Key Lab Nucl Mat & Safety Assessment Shenyang 110016 Peoples R China Univ Sci & Technol China Sch Mat Sci & Engn Hefei 230026 Peoples R China

The effects of Zn injection into boric acid and lithium hydroxide solutions on the corrosion behaviors of 316LN stainless steel (SS) in simulated hot functional test (HFT) high-temperature pressurized water at 573 K were investigated. Low concentration of lithium hydroxide solutions with 20-100 ppb Zn injection are recommended for Zn-injected HFT water chemistry and the beneficial effects of Zn injection into both HFT and primary coolant water chemistry are confirmed in view of the protective properties of the oxide films on 316LN SS. The Zn in-jection involved corrosion mechanism during HFT is discussed.

关键词： A 316LN SS B EIS High-temperature solubility c Zn High temperature corrosion

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Numerical, theoretical and experimental models of the static performance of timber beams reinforced with steel, basalt and glass pre-stressed bars

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cOMPOSITE STRUcTURES 2023年 305卷

作者： Wdowiak-Postulak, Agnieszka Kielce Univ Technol Fac Civil Engn & Architecture PL-25314 Kielce Poland

The paper presents a laboratory, theoretical and numerical study of four-point bending on forty-five ply glued and solid structural beams joined at wedge joints (quality class of structural lumber KS, KG) in the technical scale (82 x 162 x 3650 mm), on unreinforced beams, and beams reinforced with prestressed steel, basalt and glass rods, in a free-support scheme. The aim of the study was to determine the load-bending, load-stress relationships in glued and solid beams and to determine the effectiveness of the reinforcement used, together with the strength, load-bearing capacity and stiffness in both steel and 10 mm diameter composite pre-stressed beams. In the case of laminated beams reinforced with prestressed steel, the stiffness increased by 13.15 %, the load carrying capacity increased by 34.41 % and ductility increased by 13.16 %. For structural solid beams assembled at wedge joints reinforced with pre-stressed steel bars, stiffness increased by 8.11 %, load carrying capacity increased by 19.55 % and ductility increased by 13.86 %. For the glued laminated beams reinforced with pre-stressed basalt bar - the load capacity increased by 31.12 %, stiffness increased by 9.91 % and ductility increased by 9.87 %;while for the pre-stressed glass bar -load capacity increased by 29.04 %, stiffness increased by 9.70 % and ductility increased by 17.11 %. For the adopted design model of flexural beams strengthened with prestressed rods, the effectiveness of reinforcement with respect to stiffness was slightly higher than that ob-tained in laboratory tests. The numerical analysis is applicable to the design of various reinforcement schemes with particular reference to the configuration of wood quality classes.

关键词： A Wood B Strength c Numerical analysis D Mechanical testing

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cryogenic mechanics and damage behaviors of carbon fiber reinforced polymer composites

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cOMPOSITES PART A-APPLIED ScIENcE AND MANUFAcTURING 2023年第1期169卷

作者： Li, Yuanchen Meng, Jinxin Luo, Junrong Wang, Panding Ma, Jia Zhao, Zeang Lei, Hongshuai Beijing Inst Technol Beijing Key Lab Lightweight Multifunct Composite M Beijing 100081 Peoples R China Shanghai Inst Aerosp Syst Engn Shanghai 201109 Peoples R China

carbon fiber reinforced polymer (cFRP) composites, which have excellent mechanical properties, are extensively employed under extreme service conditions such as cryogenic storage tanks. In this paper, a multi-scale model was developed to investigate the cryogenic mechanical performances of cFRP composites. An elastic-plastic damage law for epoxy resin was established based on experimental results, taking into account temperature dependencies. Microscopic models and macroscopic failure criteria were formulated to describe the cryogenic mechanical behavior, and in-situ cryogenic tests were conducted on laminates. Using this multiscale framework, the effects of the cryogenic environment on the mechanical properties and failure behaviors of cFRP composites were analyzed. According to the results, the characteristics of composites at low temperatures are embrittlement transformation and delamination damage. The predicted cryogenic properties and damage behaviors matched well with the in-situ test results. This study presents an efficient method for analyzing the structural performance and designing materials for cryogenic applications.

关键词： A Polymer-matrix composites (PMcs) c Damage mechanics D Mechanical testing cryogenic mechanical properties

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Kinetic and thermodynamic studies of novel acid phosphatase isolated and purified from carthamus oxyacantha seedlings

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INTERNATIONAL JOURNAL OF BIOLOGIcAL MAcROMOLEcULES 2023年第1期224卷 20-31页

作者： Zaman, Umber Khan, Shahid Ullah Hendi, Awatif A. Rehman, Khalil Ur Badshah, Syed Refat, Moamen S. Alsuhaibani, Amnah Mohammed Ullah, Kalim Wahab, Abdul Gomal Univ Inst Chem Sci Dera Ismail Khan Pakistan Khyber Med Univ KPK Women Med & Dent Coll Dept Biochem Peshawar Pakistan Natl Key Lab Crops Genet & Improvement Wuhan Peoples R China Princess Nourah bint Abdulrahman Univ Coll Sci Dept Phys POB 84428 Riyadh 11671 Saudi Arabia Taif Univ Coll Sci Dept Chem POB 11099 Taif 21944 Saudi Arabia Princess Nourah bint Abdulrahman Univ Coll Educ Dept Phys Sport Sci POB 84428 Riyadh 11671 Saudi Arabia Kohat Univ Sci & Technol Dept Zool Kohat Khyber Pakhtunk Pakistan Kohat Univ Sci & Technol Dept Pharm Kohat Khyber Pakhtunk Pakistan

Acid phosphatase (AcP) is a key enzyme in the regulation of phosphate feeding in plants. In this study, a new AcP from c. oxyacantha was isolated to homogeneity and biochemically described for the first time. Specific activity (283 nkat/mg) was found after 2573 times purification fold and (17 %) yield. Using SDS-PAGE under denaturing and nondenaturing conditions, AcP was isolated as a monomer with a molecular weight of 36 kDa. Lc-MS/MS confirmed the presence of this band, suggesting that c. oxycantha AcP is a monomer. The enzyme could also hydrolyze orthophosphate monoester with an optimal pH of 5.0 and a temperature of 50 degrees c. Ther-modynamic parameters were also determined (Ea, Delta H degrees, Delta G degrees, and Delta S degrees). AcP activity was further studied in the presence of cysteine, DTT, SDS, EDTA, beta-ME, Triton-X-100 H2O2, and PMSF. The enzyme had a Km of 0.167 mM and an Ea of 9 kcal/mol for p-nitrophenyl phosphate. The biochemical properties of the c. oxyacantha enzyme distinguish it from other plant acid phosphatases and give a basic understanding of AcP in c. oxyacantha. The results of this investigation also advance our knowledge about the biochemical significance of AcP in c. oxyacantha. Thermal stability over a wide pH and temperature range make it more suitable for use in harsh industrial environments. However, further structural and physiological studies are anticipated to completely comprehend its important aspects in oxyacantha species.

关键词： Isolation Purification Acid phosphatase c oxyacantha Seeds

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corrosion behaviour of the microbially modified surface of 5083 aluminium alloy

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cORROSION ScIENcE 2023年第Part1期210卷

作者： Nkoua, c. Josse, c. Proietti, A. Basseguy, R. Blanc, c. Univ Toulouse CNRS INP ENSIACETCIRIMAT 4 Allee Emile MonsoCS 44362 F-31030 Toulouse 4 France Univ Toulouse CNRS INP UPSINSAUAR Raimond Castaing 3 Rue Caroline Aigle F-31400 Toulouse France Univ Toulouse CNRS INP LGCUPS 4 Allee Emile MonsoCS 44362 F-31030 Toulouse 4 France

The influence of microorganism-induced surface modifications on the corrosion behaviour of 5083 H11 aluminium alloy was studied. Pre-immersion in natural seawater (between 15 days and 2 months) led to the growth of a dense oxy-hydroxyde layer on the AA5083 surface. This layer led to a decrease in the cathodic and corrosion current densities, and an increase in the passivity domain on the polarisation curves plotted in chloride-containing sulphate solution for pre-immersed samples compared to bare samples. This improvement in the corrosion behaviour of AA5083 depended on the alloy microstructure, and the sunlight exposure during the pre-immersion in natural seawater.

关键词： A aluminium intermetallics B polarization c pitting corrosion microbiological corrosion

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Nanosized Hf6Ta2O17 particles reinforced Hfc ceramic coating for high temperature applications

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JOURNAL OF THE EUROPEAN cERAMIc SOcIETY 2023年第8期43卷 3043-3052页

作者： Feng, Guanghui Yu, Yulan Yao, Xiyuan Wu, Xiaopeng Zhang, Hao Jia, Yujun Li, Hejun Northwestern Polytech Univ Shaanxi Key Lab Fiber Reinforced Light Composite M Xian 710072 Peoples R China

There is an urgent need for the thermal protection of carbon/carbon composites to increase their service span in aerospace field. As members of ultra-high temperature ceramics, Hfc and Zrc are thought to be alternative materials, but their poor oxidation behavior and fracture toughness at temperature over 2000 degrees c prevent them from taking full advantages. Herein, we synthesized nanosized Hf6Ta2O17 powders and introduced them into Hfc ceramic to tackle the above problems. Plasma-sprayed Hfc coatings with Hf6Ta2O17 varied from 0 to 15 mol.% (0, 1.25, 2.5, 5, 15) were exposed to an oxyacetylene torch with a heat flux of 2.38 MW/m2. The one with 2.5 mol.% Hf6Ta2O17 showed the best ablation resistance. Smaller doping was unable to effectively hinder oxygen diffusion given the inadequate compactness of the formed scale, conversely substantial humps and ruptures formed on the samples with higher amounts, acting as straightforward paths for oxygen.

关键词： Sol-gel Plasma spraying c c composites Ablation resistance

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A 3D finite element stochastic framework for the failure of tow-based discontinuous composites

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cOMPOSITES ScIENcE AND TEcHNOLOGY 2023年 232卷

作者： Alves, M. Martulli, L. M. Kerschbaum, M. Swolfs, Y. Sw, S. V. Lomov Pimenta, S. Imperial Coll London Mech Engn Dept MeComposites South Kensington Campus London SW7 2AZ England Toyota Motor Europe B-1930 Zaventem Belgium Katholieke Univ Leuven Dept Mat Engn Kasteelpark Arenberg 44 Bus B-2450 Leuven Belgium

Tow-Based Discontinuous composites (TBDcs) combine high manufacturability with good mechanical proper-ties. This work presents a novel 3D approach for the numerical modelling of TBDcs. The framework generates 3D orientation tensors by adding a stochastic component to the orientation tensors deterministically predicted by a process simulation. The actual TBDcs are thus idealised as Equivalent Laminates (ELs), resulting from these stochastic tensors. A physically based 3D failure criterion is presented for the prediction of failure initiation of the ELs. The consequent stiffness reduction is captured by a ply-discount method. The approach is validated for two TBDcs materials, with two different moulding conditions and different amounts of in-mould flow. The proposed approach accurately predicts the characteristic variability of these materials. As a consequence, the predicted strength was in good agreement with the experimental results of both materials tested.

关键词： A Short-fibre composites c Finite Element Analysis (FEA) Material modelling Multiscale modelling B Strength

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