Waste Particle Size Research Articles

DRY SLIDING BEHAVIOUR OF BORON WASTE REINFORCED EPOXY MATRIX COMPOSITES

The demand for utilization of boron wastes related to the generation of massive amounts in each year is on the rise. In order to meet this growing need and demand for fabrication of environmentally friendly products, epoxy matrix composites containing 60wt% of boron wastes was developed. The influence of boron waste addition and the particle size of boron waste on epoxy matrix composites on physico-mechanical and tribological properties were evaluated. It was found that, hardness, flexural modulus and wear resistance properties were increased with the incorporation of boron wastes. Wear resistance increased with increasing boron waste particle size. The lowest specific wear rate was achieved for the largest particle size added composites. The physico-mechanical properties as well as microstructure wear behavior correlation were evaluated comprehensively.

Fuel Gas Generation from Gasification of Sacha Inchi Shell using a Drop Tube Reactor

The optimal fuel gas production conditions for gasification of sacha inchi shell waste were studied with a drop tube reactor. This waste was derived from production of sacha inchi seed oil. Ultimate, proximate and heating value of raw material were analyzed by CHNS/O analyzer, thermogravimetric analysis (TGA) and bomb calorimeter, respectively. Waste particle size was 0.50 - 0.85 mm and the reactor temperature was varied from 700 to 900°C with the equivalent ratio of 0.20 - 0.50. To reduce undesired liquid product, the Ni/dolomite was used as primary catalyst. Solid residue was analyzed for elemental composition while liquid and gas products were analyzed by gas chromatography-mass spectrometry and portable gas analyzer, respectively. It was found that at optimal operating conditions (ER 0.20, 900°C), conversions of carbon to CO, CO2 and CH4 were approximately 30.63%, 14.50% and 6.27%, respectively. Similarly, the conversion of hydrogen to H2 and CH4 were approximately 26.94% and 15.40%, respectively, with the lower heating value at 2.27 MJ/m3 and cold gas efficiency of gasification process is nearly 40% whereas liquid and solid product were 4.55 % and 34.50%. Apparently, higher temperature had a positive effect on greater gas yield and lower liquid production. Furthermore, catalyst addition reduced liquid proportion and increased potential of CO and H2 production especially for Ni loading of 5% on calcined dolomite. The result showed that conversions of carbon to CO increased to 37.95% and conversion of hydrogen to H2 increased to 34.50%. In addition, liquid and solid production decreased to 2.87% and 14.10%, respectively. The feasibility of incorporating the catalytic process on this particular thermal waste conversion method was discussed.

Study of Permeability of Glass-Sand Soil

Abstract The drainage consolidation method has been efficiently used to deal with soft ground improvement. Nowadays, it has been suggested to use a new sand soil which is a composite of sand and recycled glass waste. The permeability performance of glass-sand soil was explored to judge the feasibility of glass-sand soil backfilled in the drainage consolidation of sand-drained ground. For comparison purposes, different mix proportions of recycled glass waste, fineness modulus, and glass particle size were analyzed to certify the impact on the permeability coefficient and the degree of consolidation. The numerical results show that adding a proper amount of recycled glass waste could promote the permeability performance of glass-sand soil, and the glasssand soil drain could be consolidated more quickly than a sand drain. Experiments showed that glass-sand soil with the a 20% mix of recycled glass waste reveals the optimum performance of permeability.

Simulating municipal solid waste incineration with a DEM/CFD method – Influences of waste properties, grate and furnace design

The current work presents an initial approach of using a particle based method (Discrete Element Method, DEM) to simulate municipal solid waste (MSW) incineration on grates. Therefore, an in-house DEM code has been coupled with FLUENT. Models have been formulated for drying, volatile release and char conversion. The volatiles released are converted in the furnace above the waste bed which has been calculated with FLUENT. A comparison of simulations with measurements in an existing MSW incineration plant of CO2, O2, H2O and temperatures above the bed is presented. Agreement is fair considering the measurement uncertainties and the complexity of the process. In a sensitivity study concerning the influence of waste composition (heating value, number of waste fractions), waste particle size distribution and radiative flux onto the waste bed on conversion has been carried out. Finally, the most common grate systems, backward stoking, forward stoking and roller grates have been compared briefly, including different types of furnace geometries above the bed. The results demonstrate that the approach developed gives new insight into the complex interaction of waste movement, waste conversion and gas phase combustion above the bed which can’t be obtained with other approaches, like continuum models for the waste bed.

Characterization of Foundry Waste Sand Streams for Recycling Applications in Construction Industry

The local South African foundry industry discharges large volumes of waste sand each year, with estimates for silica and chromite sands of 250,000 and 25,000 tons, respectively. As a developing country, South Africa is moving toward a greener environment, so the management of industrial waste is an imperative area of study. In this work, we present the laboratory analysis results of the characteristics of three waste sand streams (molding, shot blast, and dust) and discuss the feasibility of reuse options in the construction industry (including concrete mix and cement manufacturing). The results reveal that each stream has its own characteristic properties. In addition, we determined the effect of the molding binder on waste sand, especially on the shakeout sand stream. The results also demonstrate that resin knock sand features much coarser grains and less clay, sulfate, and organic content than greensand. We found the chemistry of sand stream to have the same main constituents as cement kiln feed. With respect to recycling options, we determined that the shakeout stream can be reused in both concrete mix and cement manufacturing. However, special precautions should be taken regarding the clay content of sands originating from greensand foundries. Due to its finer grain size, dust streams can only be recycled in cement manufacturing. Lastly, we found that shot blast sand failed to comply with the requirements of any of the explored recycling options due to it high density, low silica content, and high metallic debris content. The effective beneficiation of sand may involve waste stream segregation and particle size classification since the recycling options we explored (concrete mix) mainly depend upon aggregate size and the impurities present (metallic debris).

The Effect of Particle size Distribution on Hydraulic Permeability in a Waste Mass

In the waste management hierarchy, the least preferable option is waste disposal. Nonetheless, disposal is an integral part of any waste management system. In a landfill, during waste degradation processes leachate is formed that can potentially cause clogging of bottom drainage layers. To ensure stability of landfill construction, the physical properties of its components have to be controlled. In a landfill, waste presents the largest structural element and often controls both the stability and integrity of the lining system. The hydrology of precipitation, evaporation, runoff and the hydraulic performance of the capping and liner materials are important controls of the moisture content. It is important to understand the hydrology of a landfill site as it affects sustainability of landfill leachate management system. The water balance also depends on waste characteristics and waste particle size distribution. Waste characteristics are closely related to the waste composition in a landfill. The aim of the study is to determine the hydraulic permeability in a landfill depending on the particle size distribution of municipal solid waste disposed. Samples were taken from a landfill operating for five years. The samples were sorted to obtain fractions with differing particle sizes. The largest fraction of the waste was within the size-range of 20–100mm. The permeability test was conducted using the column test. The paper presents the results of the test indicating higher permeability with larger waste particle size.

Chemical composition and methane potential of commercial food wastes

There is increasing interest in anaerobic digestion in the U.S. However, there is little information on the characterization of commercial food waste sources as well as the effect of waste particle size on methane yield. The objective of this research was to characterize four commercial food waste sources: (1) university dining hall waste, (2) waste resulting from prepared foods and leftover produce at a grocery store, (3) food waste from a hotel and convention center, and (4) food preparation waste from a restaurant. Each sample was tested in triplicate 8L batch anaerobic digesters after shredding and after shredding plus grinding. Average methane yields for the university dining, grocery store, hotel, and restaurant wastes were 363, 427, 492, and 403mL/dry g, respectively. Starch exhibited the most complete consumption and particle size did not significantly affect methane yields for any of the tested substrates. Lipids represented 59–70% of the methane potential of the fresh substrates.

PERMEABILITY OF DIFFERENT SIZE WASTE PARTICLES / SKIRTINGO DYDŽIO ATLIEKŲ DALELIŲ LAIDUMAS DRĖGMEI

The world and life style is changing, but the most popular disposal route for waste is landfill globally until now. We have to think about waste prevention and preparing for re-use or recycling firstly, according to the waste disposal hierarchy. Disposed waste to the landfill must be the last opportunity. In a landfill, during waste degradation processes leachate is formed that can potentially cause clogging of bottom drainage layers. To ensure stability of a landfill construction, the physical properties of its components have to be controlled. The hydrology of precipitation, evaporation, runoff and the hydraulic performance of the capping and liner materials are important controls of the moisture content. The water balance depends also on the waste characteristics and waste particle size distribution. The aim of this paper is to determine the hydraulic permeability in a landfill depending on the particle size distribution of municipal solid waste disposed. The lab experiment results were compared with the results calculated with DEGAS model. Samples were taken from a landfill operated for five years. The samples particle sizes are: >100 mm, 80 mm, 60 mm, 40 mm, 20 mm, 0.01 mm and <0.01 mm. The permeability test was conducted using the column test. The paper presents the results of experiment and DEGAS model water permeability with waste particle size. Gyvenimo būdas kiekvieną dieną keičiasi, bet vienas populiariausių būdų šalinti atliekas yra sąvartynai. Pagal atliekų šalinimo hierarchiją pirmiausia, jas šalindami, turėtumėme galvoti apie tai, kaip išvengti atliekų ir paruošti jas naudoti dar kartą. Šalinti atliekas sąvartynuose turėtų būti paskutinė galimybė. Sąvartyne vykstant biodegradacijai susiformuoja filtratas, kuris dėl sudėtingos sudėties lemia filtrato surinkimo sistemų kolmataciją. Siekdami užtikrinti stabilumą sąvartyne, turime smulkinti ar suslėgti atliekas. Kritulių, garavimo kontroliavimas yra svarbus, užtikrinant tam tikrą komunalinių atliekų drėgnumą. Vandens balansas atliekų masėje taip pat priklauso nuo atliekų savybių ir atliekų dalelių dydžio. Šio darbo tikslas yra nustatyti vandens laidumą sąvartyne priklausomai nuo komunalinių atliekų dalelių dydžio pasiskirstymo. Laboratorinio eksperimento metu gauti rezultatai buvo palyginti su DEGAS modeliu gautais rezultatais. Tyrimui mėginiai buvo paimti iš sąvartyno, kurio amžius yra penkeri metai. Mėginių dalelių dydžiai yra: >100 mm, 80 mm, 60 mm, 40 mm, 20 mm, 0,01 mm ir <0,01 mm. Laidumo tyrimas buvo atliktas taikant kolonėlės testą. Straipsnyje pateikiami eksperimento metu ir taikant DEGAS modelį apskaičiuoti vandens laidumo rezultatai, esant skirtingo dydžio atliekų dalelėms.

Lightweight Material Made with Gypsum and EPS Waste with Enhanced Mechanical Strength

AbstractHuge volumes of expanded polystyrene (EPS) waste are landfilled every year, increasing the damage that the environment is suffering. The production of a lightweight construction material made with gypsum and EPS waste is an alternative method to reduce EPS waste landfilling. However, this material has a very low mechanical strength, not meeting the minimum requirement for compressive strength. Therefore, the aim of this research work is to study the reinforcement of this lightweight material by incorporating different additives (latex, binding additive, plasticizers) and fibers (glass fiber and polypropylene fiber). Detailed consideration is given to the particle size of EPS waste; therefore, reinforced composites have been designed for fine EPS waste (1–2 mm) and coarse EPS waste (2–4 mm). The characteristics of these composites were defined and tested by fixing the consistency at a good workability and then studying their density, Shore C surface hardness, flexural and compressive strength, and ...

Influence of green solvent extraction on carotenoid yield from shrimp (Pandalus borealis) processing waste

In this work, sunflower oil (SF) and methyl ester of sunflower oil (ME-SF) were introduced as two green solvents for extracting astaxanthin (ASX) from shrimp processing waste. The effects of temperature (25, 45, 70°C), solvent to waste ratio (3, 6, 9), waste particle size (0.6 and 2.5mm) and moisture content (0% and 86.8%) as well as stirrer speed (120, 200, 400rpm) were studied during the process. In all the experiments, ASX yields from extraction with ME-SF were higher than with SF. For both solvents, the highest ASX content using a short extraction time was achieved at a temperature of 70°C, a solvent to waste ratio of 9 and a stirrer speed of 400rpm while the waste particle size and moisture content were 0.6mm and 86.8%, respectively. ME-SF and SF seem promising solvents extracting respectively about 80% and 60% of the total ASX extracted by organic solvents.

Chemical Characterization of Organic Residues in Agroindustrial and Urban Waste using Energy Dispersive X-ray Fluorescence Spectrometry

Treated and reused industrial residues and urban waste are depicted as potential alternative sources for agricultural use. In this context, the objective of this study was to determine the chemical element concentrations in organic residues from the Medium-High Uruguay Region of the Rio Grande do Sul, using energy dispersive x-ray fluorescence spectrometry (EDXRF). The organic compounds analyzed were meat agroindustry sludge, organic composites from agribusiness meat, and organic compounds from urban waste (particle sizes: >4.75 mm, <4.75 mm to >2.00 mm, and <2.00 mm). The results showed that chemical elements found in greater concentrations were calcium, silicon, iron, aluminum, phosphorus, sulphur, and potassium. Thus, the EDXRF technique proves to be efficient for characterizing organic compounds and that these residues are appropriate as alternative sources of organic fertilizer that can be applied in an efficient and safe manner in agricultural systems.

Influence of FRP Waste on the Properties of Unsaturated Polyester Resin Based Artificial Marble

There is a lot of glass fiber reinforced plastic (FRP) waste every year. Its low utilization rate and serious secondary pollution cause many problems. In this paper, FRP waste was added to enhance unsaturated polyester resin based artificial marble. The effects of FRP waste content and its particle size on the mechanical properties of artificial marble were discussed. Results show that the FRP waste content and its particle size are closely related to the mechanical properties of artificial marble. The artificial marble with FRP waste particle size of less than 0.075 mm and content of 12.5 wt % got the best mechanical properties, whose flexural strength was 23.72 MPa and compressive strength was 79.13 MPa, increased by 75.8 % and 128.1 %, respectively, compared with the strength of artificial marble with no FRP waste.

주방용 오물분쇄기로 처리된 음식물류 폐기물의 혐기성 수소 발효

Abstract >> This study was conducted to evaluate the characteristics of mesophilic fermentative H 2 productionfrom food waste which was treated by food waste disposer. It was found that H 2 yield and lag phase were affectedby particle size of food waste. The H 2 yield decreased with increasing particle size while lag phase increased.The maximum H 2 yield was found 0.584±0.03 mol H 2 /mol hexose at particle size smaller than 0.30 mm. TheH 2 production rate was also affected by chemical composition of food waste. The H 2 production rate linearly decreased with increasing proteins to carbohydrates ratio(P/C ratio) where the maximum value was 0.031±0.006mol H 2 /mol hexose·h at 0.17. Key words : Food waste(음식물류 폐기물), Anaerobic H 2 fermentation(혐기성 수소 발효), Food waste disposer(주방용 오물분쇄기), Particle size(입자 크기), Proteins to Carbohydrates ratio(단백질/탄 수화 물 비 ) † Corresponding author : chaeyoung@suwon.ac.kr [ 접수일 : 2014.10.12 수정일 : 2014.10.28 게재확정일 : 2014.10.31 ]Copyright ⓒ 2014 KHNES 1. 서 론

Influence of Particle Size of Municipal Solid Waste Amendments and Presence or Absence of Eisenia fetida on Soil Greenhouse Gases Emission

We investigated in the laboratory the influence of a municipal solid waste applied to soil at two different particle sizes (<2 and <0.5 mm) and the presence or absence of the Eisenia fetida earthworm on soil carbon dioxide (CO2) and nitrous oxide (N2O) fluxes, as well as on the changes in chemical [ammonium nitrogen (NH4+-N), nitrate nitrogen (NO3—N), soluble carbon (C), and soluble carbohydrates] and biochemical (dehydrogenase activity) properties of the soil. The presence of Eisenia fetida caused an increase in the emission of both gases (CO2 and N2O) in municipal solid waste (MSW)–amended soils due to the enhanced soil microbial activity and the degradation of the exogenous organic matter. Soil gas fluxes were influenced by the particle size of the organic waste added. The lowest particle size (<0.5 mm) increased the contact surface of the organic amendment, facilitating the accessibility to the microorganisms, enhancing soil biological activity, and the mineralization of the organic matter.

Characterization mixtures of thick gypsum with addition of treated waste from laminated plasterboards

nvironmental protection involves the reuse of construction and demolition waste. In order to improve recycling, waste from laminated plasterboards is used in the cement and laminated gypsum boards manufacture.This article analyzes the use of ground and burnt laminated plasterboard (BLG) waste mixed with thick gypsum (TG). Physical-mechanical characterization of superficial hardness and mechanical strength has been performed on different batches of plaster powder materials with different BLG waste particle sizes to determine its suitability. Coarse particle sizes were preferred in order to reduce the waste treatment. From all the mixtures studied, the one with the best results was TG + 5% BLG1.25 which forms a material of higher superficial hardness and strength. The results obtained in the study have proved suitable products for building use (both as renders and as prefabricated elements) enabling for a reduction in the consumption of natural resources.

Determination of specific gravity of municipal solid waste

This investigation was conducted to evaluate experimental determination of specific gravity (Gs) of municipal solid waste (MSW). Water pycnometry, typically used for testing soils was adapted for testing MSW using a large flask with 2000mL capacity and specimens with 100–350g masses. Tests were conducted on manufactured waste samples prepared using US waste constituent components; fresh wastes obtained prior and subsequent to compaction at an MSW landfill; and wastes obtained from various depths at the same landfill. Factors that influence specific gravity were investigated including waste particle size, compaction, and combined decomposition and stress history. The measured average specific gravities were 1.377 and 1.530 for as-prepared/uncompacted and compacted manufactured wastes, respectively; 1.072 and 1.258 for uncompacted and compacted fresh wastes, respectively; and 2.201 for old wastes. The average organic content and degree of decomposition were 77.2% and 0%, respectively for fresh wastes and 22.8% and 88.3%, respectively for old wastes. The Gs increased with decreasing particle size, compaction, and increasing waste age. For fresh wastes, reductions in particle size and compaction caused occluded intraparticle pores to be exposed and waste particles to be deformed resulting in increases in specific gravity. For old wastes, the high Gs resulted from loss of biodegradable components that have low Gs as well as potential access to previously occluded pores and deformation of particles due to both degradation processes and applied mechanical stresses. The Gs was correlated to the degree of decomposition with a linear relationship. Unlike soils, the Gs for MSW was not unique, but varied in a landfill environment due both to physical/mechanical processes and biochemical processes. Specific gravity testing is recommended to be conducted not only using representative waste composition, but also using representative compaction, stress, and degradation states.

Study on Formation Mechanism of Dumping Piles on Dumping Area Stability

Dumping areas represent a stable hazard. To clarify the formation mechanism of dumping piles on dumping area stability, an investigation in open pit mine was performed. Moreover, experiments with gravel were conducted based on the research site conditions. The geological conditions, dumping operation, and waste particle size distribution were investigated in the Heidaigou open pit mine. Particle size distribution, dumping height, dumping volume, and floor inclination were varied to examine their effects on a single pile formation. The design of blasting can be modified to make the particle size of waste smaller. The volume of the bucket does not have a pronounced effect on dumping pile repose angle, capacity of dumping pile, and dumping area stability. The smaller the floor inclination, the better it is. Two measures are proposed to increase the kinetic force of friction between waste material and floor surface. The interval distance, dumping volume and dumping height were also varied to examine the interaction between the formations of multiple piles. The dumping width should be decided through optimization efficiency of bulldozer and dumping device in bucket wheel excavator-belt-stacker dumping operation and dragline dumping operation. Moreover, the volume of the bucket does not have a pronounced interaction effect. In the dumping operation, the work amount of bulldozer decreases as dumping pile increases. The design of the dumping operation must consider the total efficiency of ground leveling operation and forming dumping the area.

Anaerobic co-digestion of food waste and dairy manure: Effects of food waste particle size and organic loading rate

This study was to comprehensively evaluate the effects of food waste particle size on co-digestion of food waste and dairy manure at organic loading rates increased stepwise from 0.67 to 3g/L/d of volatile solids (VS). Three anaerobic digesters were fed semi-continuously with equal VS amounts of food waste and dairy manure. Food waste was ground to 2.5mm (fine), 4mm (medium), and 8mm (coarse) for the three digesters, respectively. Methane production rate and specific methane yield were significantly higher in the digester with fine food waste. Digestate dewaterability was improved significantly by reducing food waste particle size. Specific methane yield was highest at the organic loading rate of 2g VS/L/d, being 0.63, 0.56, and 0.47LCH4/g VS with fine, medium, and coarse food waste, respectively. Methane production rate was highest (1.40–1.53LCH4/L/d) at the organic loading rate of 3gVS/L/d. The energy used to grind food waste was minor compared with the heating value of the methane produced.

Effects of key parameters in recycling of metals from petroleum refinery waste catalysts in bioleaching process

Environmental laws concerning spent catalysts disposal have become increasingly more severe in recent years. Due to the toxic nature of spent catalysts, their disposal can pollute the environment. The recovery of heavy metals decreases the environmental impact of the waste catalysts and the recycled product can be further used for industrial purposes. Bio-hydrometallurgical approaches, such as bioleaching, appear to offer good prospects for recovering valuable metals from spent refinery catalysts. Currently, identifying and modifying the parameters that influenced the efficiency of bioleaching is important for industrial sector. The biological system can be further improved through optimizing the bioleaching parameters, such as the nutrient culture media, amount of oxygen and carbon dioxide, pH, temperature, inoculum, metal resistance of microorganisms, chemistry of solid waste, particle size of solid waste, solid liquid ratio, bioleaching period, size of substrate, shaking speed, and also the development of more effective bioleaching microorganisms. In our previous review (Asghari et al. in J Ind Eng Chem 19:1069–1081, 2013), information available in the literature on the bioleaching fundamentals of spent catalysts with a focus on recent developments was reviewed in detail. In this study, the effects of most important factors that influence an efficient bioleaching process of spent refinery catalysts with the hope that these valuable and useful data can help determine the most efficient process will be discussed. The details of metals recovery with a focus on the effects of different variables in the bioleaching such as reaction time, pulp density, initial pH, particle size, nutrient concentration, temperature and buffer will also be presented.

The Impact of Biomass Cofiring on Volatile Flame Length

The physical characteristics and composition of biomass can vary significantly from coal and from one fuel to another, and these differences can impact the structure of the resulting pulverized fuel flame, particularly the volatile flame. The length and location of the volatile flame, which is the zone dominated by the combustion of volatiles, is important not only to flame stability and length but also to the formation of pollutants such as NOx. In this work, the effects of biomass volatile fraction and particle size on the length of the volatile flame were investigated for cofired flames of pulverized coal and wood waste. The volatile flame length was measured experimentally in a 35 kW combustion facility via axial measurements of CO and CO2 made along the centerline. Numerical simulations were employed to aid the interpretation of the impacts of wood waste cofiring on the volatile flame. The length of the volatile flame zone was found to be sensitive to the location of volatile matter release and the amount of volatile matter released within the volatile flame zone. Large biomass particles, with high axial momentum and long heating times, break through the fuel-rich volatile flame zone, releasing volatiles downstream into an oxygen-rich environment. The delayed release of volatiles reduces the amount of volatile fuel in the fuel-rich region, leading to shorter volatile flames, which in turn augments breakthrough of particles before complete release of volatiles. On the basis of CO and CO2 concentration measurements, cofired flames with 20 wt % wood waste and 80 wt % coal were found to have 21% shorter volatile flames compared with coal-only flames. Numerical simulations verified that volatile reactions take place past the end of the volatile flame. To reduce the amount of particles that pass through the volatile flame before complete devolatilization, the wood waste particle size was reduced. The resulting volatile flame was 27% longer for the 20 wt % cofired case compared with coal-only volatile flames. Increased volatile matter content, characteristic of biomass fuels, leads to an increased volatile flame length when all of the volatiles are released in the near-burner region.