Effect of natural and modified zeolite addition on anaerobic digestion of piggery waste

2003 ◽  
Vol 48 (6) ◽  
pp. 263-269 ◽  
Author(s):  
Z. Milán ◽  
P. Villa ◽  
E. Sánchez ◽  
S. Montalvo ◽  
R. Borja ◽  
...  
Keyword(s):  
Natural Zeolite ◽  
Organic Load ◽  
Second Phase ◽  
Modified Zeolite ◽  
Waste Solid ◽  
Modified Zeolites ◽  
Two Phases ◽  
Gas Volume ◽  
Potential Biodegradability

The effect of natural and modified zeolites on the anaerobic degradation of acetate and methanol was evaluated by the determination of specific methane productivity (SMP) in batch minidigesters of 50 mL at doses of 0.01, 0.05 and 0.1 g of zeolite/g of VSS. The effects of the different zeolite concentrations were determined by the results of the SMP. A kinetic characterization with data of accumulated methane gas volume was also carried out. In the second phase of the study, the effects of natural and nickel zeolite concentrations were tested with piggery waste in laboratory scale digesters of 2.5 L operating at semi continuous mode, by increasing the organic load applied from 0.2 to 22.0 g TCOD/d corresponding to organic loading rates (OLR) of 0.1-8.8 g TCOD/l.d. A greater effect of modified zeolite on SMP was observed, with an increase of 8.5 times with magnesium zeolite, 4.4 times with cobalt zeolite and 2.8 times with nickel zeolite. Two phases were defined in the kinetic study and an increase of more than 2 times the apparent constant of digesters with modified zeolites was observed in the second phase when compared to unmodified natural zeolite. Modified natural zeolite addition to digesters can allow an increase in the potential biodegradability of piggery waste solid fraction and/or a considerable reduction of digestion volume.

scholarly journals Fluoride ion adsorption from wastewater using magnesium(II), aluminum(III) and titanium(IV) modified natural zeolite: kinetics, thermodynamics, and mechanistic aspects of adsorption

2017 ◽  
Vol 8 (4) ◽  
pp. 479-489 ◽  
Author(s):  
Zhijun Ma ◽  
Qi Zhang ◽  
Xingyuan Weng ◽  
Changye Mang ◽  
Liwei Si ◽  
...  
Keyword(s):  
Natural Zeolite ◽  
Adsorption Process ◽  
Fluoride Ion ◽  
Ion Adsorption ◽  
Order Model ◽  
Fluoride Ions ◽  
Modified Zeolite ◽  
Fluoride Adsorption ◽  
Pseudo Second Order ◽  
Modified Zeolites

Abstract Natural zeolite was modified using metal ions, including magnesium(II), aluminum(III) and titanium(IV). The modified zeolite was then used as an adsorbent for the investigation of the adsorption kinetics, isotherms, and thermodynamic parameters of fluoride ions in wastewater at various pHs and temperatures. The kinetics and thermodynamics for the removal of the fluoride ions onto the modified zeolite have also been investigated. The fluoride ion adsorption capacity of the three types of modified zeolites exhibited an increase, then decrease, with rising pH. The fluoride adsorption capacity of the modified zeolites decreased with an increase in temperature. The pseudo-second-order model is more suitable for describing the adsorption kinetic data than the pseudo-first-order model for modified zeolite and the adsorption process of the fluoride ions reveals pseudo-second-order kinetic behavior, respectively. It was found that the adsorption equilibrium data fit the Freundlich isothermal equation better than that of the Langmuir isothermal and Dubinin–Radushkevich (D–R) isothermal equations. Thermodynamic analysis suggests that the negative values of ΔG0 and ΔH0 further indicate that the fluoride adsorption process is both spontaneous and exothermic. The results of competitive adsorption tests suggest that the modified metal zeolite materials adsorb fluoride ions with high selectivity.

scholarly journals Potentials for commercial production of biogas from domestic food waste generated in Benin Metropolis, Nigeria

2016 ◽  
Vol 20 (2) ◽  
pp. 369-373
Author(s):  
E.P. Akhator ◽  
D.I. Igbinomwanhia ◽  
A.I. Obanor
Keyword(s):  
Solid Waste ◽  
Food Waste ◽  
Solid Waste Management ◽  
Biogas Production ◽  
Second Phase ◽  
Biodegradable Waste ◽  
Daily Food ◽  
Two Phases

The work reported in this paper investigated the potentials of commercial biogas production from biodegradable waste in Benin metropolis. The study was carried out in two phases. The first phase involved characterization of solid waste generated and determination of the quantity of potential feed stock for biogas production in Benin metropolis and the second phase was determination of the amount of biogas obtainable from biodegradable waste. The results from the study showed that an average daily generation rate of 0.358kg per person per day (ppd.) of solid waste is generated in study area. Food waste accounted for about 78.49% of the generated solid waste representing 0.281kg per person per day (ppd.) and a total daily food waste generation of 305.075tonnes. Based on this value for food waste the obtainable biogas was estimated to be 28,836.91m3 of biogas in Benin metropolis per day. This volume of biogas can provide cooking gas for about 24,076.91 families per month in Benin metropolis or alternatively can be utilised to generate about 49.023MW of electricity per day.Keywords: Solid waste management, food waste, anaerobic digestion, biogas

scholarly journals Preparation and application of modified zeolites as adsorbents in wastewater treatment

2018 ◽  
Vol 2017 (3) ◽  
pp. 621-635 ◽  
Author(s):  
Jiahui Shi ◽  
Zixuan Yang ◽  
Hongliang Dai ◽  
Xiwu Lu ◽  
Lihong Peng ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Wastewater Treatment ◽  
Constructed Wetlands ◽  
Natural Zeolite ◽  
Review Paper ◽  
Large Specific Surface Area ◽  
Modified Zeolite ◽  
Modified Zeolites ◽  
Surface Modified ◽  
Modification Treatment

Abstract Natural zeolite has been recognized as a useful adsorbent for wastewater treatment for removing cations. Natural zeolite is a kind of porous material with large specific surface area but limited adsorption capacity. In recent years, emphasis has been given to prepare the surface modified zeolite using various procedures to enhance the potential of zeolite for pollutants. Modification treatment for zeolite can greatly change surface chemistry and pore structure. The article describes various modification methods of zeolite, and introduces the removal mechanisms of common pollutants such as ammonium, phosphorus and heavy metals. In addition, this review paper intends to present feasibility of applying modified zeolite to constructed wetlands which will be beneficial to achieve higher removal effect.

scholarly journals INFLUENCE OF THE NATURE OF THE MODIFIER ON THE SORPTION PROPERTIES OF SHANKANAI ZEOLITE

2021 ◽  
Vol 3 ◽  
pp. 36-46
Author(s):  
R.А. Kaiynbayeva ◽  
◽  
N.N. Kojabekova ◽  
G.Sh. Sultanbayeva ◽  
А.А. Аgatayeva ◽  
...  
Keyword(s):  
Hydrochloric Acid ◽  
Cation Exchange ◽  
Natural Zeolite ◽  
Physicochemical Analysis ◽  
Sorption Properties ◽  
Zeolite A ◽  
Optimal Temperature ◽  
Modified Zeolite ◽  
Modified Zeolites ◽  
Sorption Characteristics

Sorbents modified with hydrochloric acid and chitosan based on the Shankanai bridge formation zeolite were obtained, and the effect of drying temperature on the sorption properties of sorbents was studied. It was found that 25 °C is the optimal temperature for obtaining acid-modified zeolite. A chitosan-modified sorbent with good sorption characteristics can be obtained at 25 °C with cation-exchange (COE 68.05 mg-eq/g) and 70°C with anion-exchange (SEC 70.16 mg-eq/g) properties. Physicochemical analysis of modified zeolites showed an increase in the size of voids and channels on the surface of acid-modified zeolite, and when modified with chitosan, the latter is crosslinked with the surface of natural zeolite.

Effect of Hydrogen Peroxide on soil Organic Matter

1931 ◽  
Vol 21 (2) ◽  
pp. 251-261 ◽  
Author(s):  
W. McLean
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Second Phase ◽  
Carbon And Nitrogen ◽  
Carbohydrate Complex ◽  
Carbon Compounds ◽  
Carbon Nitrogen Ratio ◽  
Nitrogen Ratio ◽  
Two Phases

1. Six per cent. peroxide is found to be unsuitable as a reagent for the determination of the “degree of humification” of soil organic matter, as it oxidises not only compounds containing carbon and nitrogen but also a varying amount of a substance containing carbon but no nitrogen, this amount depending on the volume of reagent used and the total amount of carbon originally present in the quantity of soil employed.2. There are apparently two phases in the attack of peroxide on soil organic matter. In the first phase, material containing carbon and nitrogen is oxidised, whilst in the second phase the material oxidised consists solely of nitrogen-free carbon compounds.3. By the use of 3 per cent. peroxide (2 per cent, or less may be preferable for some soils) the attack on soil organic matter can be restricted to the first phase. The material thus oxidised appears to be built up by the association of a protein complex with a carbohydrate complex of high carbon content. Its carbon-nitrogen ratio is about 10:1.

scholarly journals Optimized steps in determination of malondialdehyde (MDA) standards on diagnostic of lipid peroxidation

2018 ◽  
Vol 30 (2) ◽  
pp. 136
Author(s):  
Prima Nanda Fauziah ◽  
Ani Melani Maskoen ◽  
Tri Yuliati ◽  
Erlina Widiarsih
Keyword(s):  
Lipid Peroxidation ◽  
High Sensitivity ◽  
Thiobarbituric Acid ◽  
Oxidation Products ◽  
Second Phase ◽  
Thiobarbituric Acid Reactive Substances ◽  
Acetic Acid Medium ◽  
Standard Curve ◽  
Two Phases

Introduction: Lipid peroxidation, one of the known indices of oxidative stress, is documented in various diseases. Secondary oxidation products such as malondialdehyde (MDA) is commonly measured to observe lipid peroxidation. In this study, a spectrophotometric method was evaluated to measure thiobarbituric acid reactive substances (TBARS) with high sensitivity. This study was aimed to optimisation standard of MDA using tetraethoxypropane (TEP) 97% (FW=220.3). Methods: The method is based upon the reaction of malondialdehyde (MDA) and TBA in the glacial acetic acid medium. MDA is a known biomarker of oxidative status in a biological system. This research consists of two phases: first, making a stock of TEP, and the second phase was testing the concentration of TEP for finding the standard curve of MDA before used in diagnostic of lipid peroxidation. Results: Result showed the concentration 1,875-60 uM of TEP could form a precise standard curve. Conclusion: This concentration of TEP can be used as a reference as the standard of control in diagnostic of lipid peroxidation using TBARS method.

Polishing process effect on the image of dispersed precipitates

1984 ◽  
Vol 42 ◽  
pp. 534-535
Author(s):  
C.T. Hu ◽  
C.W. Allen
Keyword(s):  
Matrix Material ◽  
Specimen Preparation ◽  
Second Phase ◽  
Precipitate Particle ◽  
Polishing Process ◽  
Second Phase Particles ◽  
The Matrix ◽  
Surface Profiles ◽  
Thinning Process

One important problem in determination of precipitate particle size is the effect of preferential thinning during TEM specimen preparation. Figure 1a schematically represents the original polydispersed Ni3Al precipitates in the Ni rich matrix. The three possible type surface profiles of TEM specimens, which result after electrolytic thinning process are illustrated in Figure 1b. c. & d. These various surface profiles could be produced by using different polishing electrolytes and conditions (i.e. temperature and electric current). The matrix-preferential-etching process causes the matrix material to be attacked much more rapidly than the second phase particles. Figure 1b indicated the result. The nonpreferential and precipitate-preferential-etching results are shown in Figures 1c and 1d respectively.

Determination of creep mechanisms in various silicon carbides via TEM

1986 ◽  
Vol 44 ◽  
pp. 484-487
Author(s):  
C. H. Carter ◽  
J. E. Lane ◽  
J. Bentley ◽  
R. F. Davis
Keyword(s):  
Heat Exchangers ◽  
Sintered Material ◽  
Polycrystalline Material ◽  
Chemical Vapor ◽  
Graphite Substrate ◽  
Second Phase ◽  
Reaction Bonding ◽  
Creep Mechanisms ◽  
Porous Sic

Silicon carbide (SiC) is the generic name for a material which is produced and fabricated by a number of processing routes. One of the three SiC materials investigated at NCSU is Norton Company's NC-430, which is produced by reaction-bonding of Si vapor with a porous SiC host which also contains free C. The Si combines with the free C to form additional SiC and a second phase of free Si. Chemical vapor deposition (CVD) of CH3SiCI3 onto a graphite substrate was employed to produce the second SiC investigated. This process yielded a theoretically dense polycrystalline material with highly oriented grains. The third SiC was a pressureless sintered material (SOHIO Hexoloy) which contains B and excess C as sintering additives. These materials are candidates for applications such as components for gas turbine, adiabatic diesel and sterling engines, recouperators and heat exchangers.

Accurate Detection and Quantization of Leaf- Diseases through Soft Computing

2018 ◽  
Vol 1 (1) ◽  
pp. 236-247
Author(s):  
Divya Srivastava ◽  
Rajitha B. ◽  
Suneeta Agarwal
Keyword(s):  
Machine Learning ◽  
Image Processing ◽  
Agricultural Production ◽  
Bacterial Blight ◽  
Early Stage ◽  
Second Phase ◽  
Computationally Efficient ◽  
Stage Of Disease ◽  
Accurate Detection ◽  
Two Phases

Diseases in leaves can cause the significant reduction in both quality and quantity of agricultural production. If early and accurate detection of disease/diseases in leaves can be automated, then the proper remedy can be taken timely. A simple and computationally efficient approach is presented in this paper for disease/diseases detection on leaves. Only detecting the disease is not beneficial without knowing the stage of disease thus the paper also determine the stage of disease/diseases by quantizing the affected of the leaves by using digital image processing and machine learning. Though there exists a variety of diseases on leaves, but the bacterial and fungal spots (Early Scorch, Late Scorch, and Leaf Spot) are the most prominent diseases found on leaves. Keeping this in mind the paper deals with the detection of Bacterial Blight and Fungal Spot both at an early stage (Early Scorch) and late stage (Late Scorch) on the variety of leaves. The proposed approach is divided into two phases, in the first phase, it identifies one or more disease/diseases existing on leaves. In the second phase, amount of area affected by the disease/diseases is calculated. The experimental results obtained showed 97% accuracy using the proposed approach.

Representação e simbolismo: artes visuais na fronteira Brasil/Bolívia

2020 ◽  
Vol 4 (3) ◽  
pp. 286
Author(s):  
Paulo César Antonini de Souza ◽  
Derick Trindade Bezerra
Keyword(s):  
Visual Arts ◽  
Social Order ◽  
Research Field ◽  
Border Region ◽  
Second Phase ◽  
Two Dimensional ◽  
Santa Cruz ◽  
Cultural Conditions ◽  
Two Phases ◽  
America Latina

ResumoTendo por campo de investigação o Festival da América do Sul Pantanal (FASP) em 2018, na cidade de Corumbá (Brasil), objetiva-se identificar a materialidade e conceitos que permeiam as manifestações artísticas bidimensionais nesta região de fronteira, a partir da percepção de artistas da Bolívia. A pesquisa se organizou em duas fases: na primeira foi realizado um levantamento em plataformas online de produções acadêmicas em artes visuais, com foco no trabalho bidimensional, utilizando os descritores “arte popular” e “estética latina” resultando em três artigos. Na segunda fase foram selecionados dois trabalhos de uma artista da Bolívia, participante da mostra “Conexão Santa Cruz”, realizada durante o FASP 2018, que foram analisados em seus níveis representacional e simbólico. Pela interpretação das imagens foi possível construir uma leitura sobre a perspectiva da artista a respeito de suas condições culturais dentro da ordenação social em que se encontra situada.Palavras-chave: Artes Visuais. Arte Popular. Arte Regional. América Latina. Representation and symbolism: visual arts on the Brazil/Bolivia frontierAbstractHaving as research field the Festival da América do Sul Pantanal (FASP) in 2018, in the city of Corumbá (Brazil), the objective is to identify the materiality and concepts that permeate the two-dimensional artistic manifestations in this border region, from the perception of artists from Bolivia. The research was organized in two phases: in the first, a survey was carried out on online platforms of academic productions in visual arts, focusing on two-dimensional work, using the descriptors “arte popular” and “estética latina” resulting in three articles. In the second phase, two works were selected by an artist from Bolivia, participating in the exhibition “Conexão Santa Cruz”, held during FASP 2018, which were analyzed at their representational and symbolic levels. Through the interpretation of the images, it was possible to construct a reading on the artist’s perspective regarding her cultural conditions within the social order in which she is located.Keywords: Visual Arts. Folk Art. Regional Art. Latin America.Representación y simbolismo: artes visuales en la frontera de Brasil/BoliviaResumenTeniendo como campo de investigación el Festival de Sudamérica Pantanal (FASP) en 2018, en la ciudad de Corumbá (Brasil), el objetivo es identificar la materialidad y conceptos que permean las manifestaciones artísticas bidimensionales en esta región fronteriza, desde la percepción de artistas de Bolivia. La investigación se organizó en dos fases: en la primera, se realizó una encuesta en plataformas online de producciones académicas en artes visuales, con foco en el trabajo bidimensional, utilizando los descriptores “arte popular” y “estética latina” dando como resultado tres artículos. En la segunda fase, dos obras fueron seleccionadas por un artista de Bolivia, participante de la exposición “Conexão Santa Cruz”, realizada durante FASP 2018, que fueron analizadas en sus niveles representativos y simbólicos. A través de la interpretación de las imágenes, fue posible construir una lectura sobre la perspectiva de la artista sobre sus condiciones culturales dentro del orden social en el que se ubica.Palabras clave: Artes Visuales. Arte Popular. Arte Regional. América Latina.

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