Raw Residue Research Articles

Three‐dimensional sound reproduction in vehicle based on data mining technique

SummaryThree‐dimensional (3D) audio reproduction technique is a hot topic since MPEG proposed a proposal for 3D audio standard in 2012. The present 3D reproduction method is not available in vehicle because the loudspeaker configuration does not meet the requirements of the methods. In this paper, we develop a regression model to reproduce sound pressure in vehicle using a data mining algorithm. A big sound pressure dataset is established based on acoustic theory. We analyze this dataset and propose a stepwise regression model training and testing on this dataset. Both the Mean Square Error and Root Mean Square Error are rather small, and all the residuals such as raw residuals, Pearson Residuals, Studentized residuals, and Standardize residuals are small as well. The experiments indicate that the proposed reproduction system accurately simulates the theoretical sound reproduction system.

Energy potential of vinasse derived from rum manufacturing

The purpose of this study is to analyse the energetic potential of the vinasse coming from the distillation of rum. 10 to 15 l of vinasse are obtained for each unit of alcohol. This is being used as fertilizer for the cultivation of sugar cane. Three samples are analysed for physical, chemical and fuel properties: raw vinasse, its distillate and residue. The results demonstrated that raw vinasse can be used as an additive to liquid fuels with a calorific value of approximately 792 kJ/kg and a boiling point above that of flammability, which flavours the non-formation of vapours. The amount of solid waste present could be detrimental to atomization inside furnaces or its flow through combustion chambers, so it must be pre-treated.

Variables Affecting Delignification of Corn Wastes Using Urea for Total Reducing Sugars Production.

In this work, a combination of mechanical and chemical pretreatments using urea on corn residues (leaves and stems) was evaluated to obtain total reducing sugars (TRSs). The residues were characterized via high-performance liquid chromatography (HPLC) to quantify biomass composition. During the mechanical pretreatment, the particle size of the biomass was reduced to 0.5, 1, and 2 mm. The chemical pretreatment was performed with urea solution at different concentrations (2, 5, and 10% w/v) and a fixed biomass-to-solvent ratio of 1:25 (g/mL) as well as stirring at 150 rpm for 20 h. The effect of temperature on the pretreatment results was evaluated by varying such operating variables in 30 and 50 °C. After both pretreatments, hydrolysis was carried out in an autoclave using sulfuric acid at 1% v/v at 121 °C for 1 h. The content of TRS was quantified using 3,5-dinitrosalicylic acid (DNS) method and biomass after pretreatment was characterized via Fourier transform infrared (FT-IR). For both leaves and stems, the HPLC technique reported the presence of 47.4 g of cellulose, 40.04 g of hemicellulose, and 26.38 g of lignin. It was found that the highest amount of TRS (36.50 g/L) was obtained with a urea concentration of 2% at 50 °C using a particle size of 0.5 mm. The production of TRS was significantly higher for pretreated biomass than that for raw corn residues, confirming the importance of both mechanical and chemical pretreatments to reach better delignification results.

Monosaccharides and carbon nanosphere obtained by acidic concentrated LiBr treatment of raw crop residues via optimizing the synthesis process

The by-product from acidic concentrated LiBr hydrolyzed (ALBH) crop residues, as ALBH biochar, showed great potential as adsorbent for removing heavy metal pollution. By optimizing the treatment conditions, this study indicated that 22.44% of cellulose was hydrolyzed to glucose, and the residues showed 86.96 mg/g of adsorption capacity to Cr(VI) after T6 treatment of elephant grass. With T3 treatment (5% solid ratio, 0.5 M HCl, at 140 °C for 150 min), the residues from treated elephant grass got 100 mg/g adsorption capability to Cr(VI). Meanwhile, the carbon sphere with uniform, dispersive and in diameter of ~100 nm was formed via the further dehydration and condensation reaction of saccharides. Among the raw feedstocks, the relative high content of cellulose (40.30%) caused elephant grass as the optimal option for carbon spheres production.

EFFECT OF KAOLIN ADDITION INTO METAKAOLIN GEOPOLYMER COMPOSITE

Industrially produced metakaolin may contain raw kaolin residues. Therefore, the aim of this work was to determine the impact of kaolin remains on the metakaolin and the final geopolymer quality. A series of mixtures based on metakaolin (Mefisto L05 by CLUZ Nove Straseci, Czech Republic) was prepared with the 0-60 wt% gradual addition of raw kaolin, and the mechanical strength of the final geopolymer products was tested. It was found that up to a 20 wt. % amount of kaolin in metakaolin does not weaken the geopolymer’s performance. Moreover, a geopolymer made of metakaolin with 2-4 wt% of kaolin showed slightly better mechanical properties than the geopolymers made from metakaolin itself.

Fluorochemicals biodegradation as a potential source of trifluoroacetic acid (TFA) to the environment

The anthropogenic release of trifluoroacetic acid (TFA) into the environmental media is not limited to photochemical oxidation of CFC alternatives and industrial emissions. Biological degradation of some fluorochemicals is expected to be a potential TFA source. For the first time, we assess if the potential precursors [6:2 fluorotelomer alcohol (6:2 FTOH), 4:2 fluorotelomer alcohol (4:2 FTOH), acrinathrin, trifluralin, and 2-(trifluoromethyl)acrylic acid (TFMAA)] can be biologically degraded to TFA. Results show that 6:2 FTOH was terminally transformed to 5:3 polyfluorinated acid (5:3 FTCA; 12.5 mol%), perfluorohexanoic acid (PFHxA; 2.0 mol%), perfluoropentanoic acid (PFPeA; 1.6 mol%), perfluorobutyric acid (PFBA; 1.7 mol%), and TFA (2.3 mol%) by day 32 in the landfill soil microbial culture system. 4:2 FTOH could remove multiple –CF2 groups by microorganisms and produce PFPeA (2.6 mol%), PFBA (17.4 mol%), TFA (7.8 mol%). We also quantified the degradation products of TFMAA as PFBA (1.3 mol%) and TFA (6.3 mol%).Furthermore, we basically analyzed the biodegradation contribution of short-chain FTOH as raw material residuals in commercial products to the TFA burden in the environmental media. We estimate global emission of 3.9–47.3 tonnes of TFA in the period from 1961 to 2019, and project 3.8–46.4 tonnes to be emitted from 2020 to 2040 via the pathway of 4:2 and 6:2 FTOH biodegradation (0.6–7.1 and 0.6–7.0 tonnes in China, respectively). Direct evidence of the experiments indicates that biodegradation of fluorochemicals is an overlooked source of TFA and there are still some unspecified mechanisms of TFA production pathways.

Analysis on the Changes of Functional Groups after Coal Dust Explosion at Different Concentrations Based on FTIR and XRD

ABSTRACT In this study, experiments were performed on coal dust explosion (CDE) at different concentrations by using a 20 L spherical explosion device. Besides, the raw coal and solid residues of CDE were subjected to FTIR and XRD analyses. The aims are to investigate the changes of functional groups after CDE at different concentrations, the relationship between functional group consumption rate and explosion characteristic parameters, and the changes of inorganic minerals. The results show that during the CDE, various functional groups are consumed to varying degrees. Among the groups, the consumption of oxygen-containing functional groups is the most, followed by those of hydroxyl groups and aliphatic hydrocarbons, and that of aromatic hydrocarbons is the least. When the coal dust concentration is greater than 200 g/m3, the functional group consumption rate exceeds 50%; when the coal dust concentration exceeds 500 g/m3, the functional group consumption rate exceeds 90%. The total consumption of functional groups is positively correlated with the explosion pressure P m, the growth rate of explosion pressure (dp/dt)m, the flame propagation velocity V F and the impulse I during the CDE experiments. Compared with raw coal, solid residues of CDE possess an increased content of minerals. The absorption peak area of minerals reaches a maximum of 10.28 (about 10 times of that for the raw coal) under the concentration of 700 g/m3. The main mineral components vary before and after the CDE. The main mineral components in the raw coal are quartz and kaolinite, while the main mineral components in the solid residues after CDE are quartz, calcium zeolite, wollastonite and magnesium oxide.

Desulfurization Performances of Activated Coke Prepared from Fine Blue-Coke

Activated coke was prepared by CO2 activation using solid waste fine blue-coke as main raw material and coal direct liquefaction residue (DCLR) as binder. The activated coke was characterized by BET, XRD, and infrared analysis. The flue gas desulfurization experiment was carried out with a fixed bed reactor and activated coke as the adsorbent. The experimental results show that coal direct liquefaction residue pyrolysis process will produce a large number of cohesive colloids, further increasing the strength of the activated coke. BET analysis shows that there is abundant microporous structure in the activated coke, infrared analysis shows that the activated coke contains abundant surface functional groups, and XRD shows that the crystallization degree of the activated coke is high. At lower temperature, SO2 and O2 have competitive adsorption on the surface of activated coke, if the concentration of water vapor is too high, a water film will be formed on the surface of activated coke, which will hinder the adsorption of SO2 by activated coke. The initial concentration of SO2 is 700 ppm, the adsorption temperature is 80 °C, the oxygen concentration is 9%, and the concentration of water vapor is 8%. The removal of SO2 by activated coke is better, and the desulfurization rate reaches 97%.

Full-scale of composting process of biogas residues from corn stover anaerobic digestion: Physical-chemical, biology parameters and maturity indexes during whole process

Recycling of biogas residues from corn stover anaerobic digestion is crucial for the development of biogas industry. Full-scale composting process is the feasible way to convert biogas residues to fertilizer. The aim of the study was to explore the feasibility of full-scale composting process to dispose biogas residue to fertilizer, and to evaluate the quality of the compost. The results showed the biogas residues could rapidly reach the thermophilic stage and last at least 20 days, NH4+-N, TOC and C/N decreased along with the composting process, while TP, TK and NO3–-N showed an opposite trend. Germination index(GI) and seedling growth index showed that raw biogas residues was toxic for plant, but the GI and seedling growth index were increased during the composting process, except for the cooling stage sample. Anaerolineaceae and Limnochordaceae were the main bacteria involved in the composting process, and Chaetomium was the most important fungus.

Characterization and Determination of Briquette Fuel Prepared from Five Variety of Corn Cob

Corn cob residue is significant potential for mere energy resource. From perspective of cost and air pollution management, exploitation of the residue fits appropriate into the strategy of sustainable development and environmentally friend. However, combusting of agricultural by-product without changing their physical nature is considered as insufficient and inefficient utilization to meet energy demand. Utilizing them in their natural form causes extensive heat loss and minimum of amount of heat energy can be recovered. Moreover raw corn cob residue has low density material and heating values when directly employed as fuel. So, converting it into a higher value energy resource is important issue. Corn cob was carbonized in carbonization technology with very limited supply of air. On drum part, about twelve holes were provided to follow up activity and boost carbonization process thereby to reduce charring time and increases conversion efficiency. After carbonization, carbonized corncob was withdrawn from reactor and charred products collected. The carbonized corn cob was crushed and grinded to fine particles in order to prepare briquette from five varieties. The briquettes were then removed from the mold and sun-dried in open air to maintain their mass. Briquette property and they calorific value were investigated employing standard methods. Thus, calorific value or HHV of BH-661, BH-541, Local, Shone and Limmu briquette were 28.58, 28.57, 27.60, 29.67 and 28.49 MJ/Kg respectively.

Carbonization of Plant Residues Decreased their Capability of Reducing Hexavalent Chromium in Soils

The mechanism of Cr(VI) immobilization in soils by organic substances are not well understood. In the present study, two crop residues (maize stalk and peanut shell) and their biochars obtained at various pyrolysis temperatures were prepared to investigate their influences on the immobilization of Cr(VI) in two contaminated soils via an incubation test and a bioassay. The results showed that Cr(VI) immobilization in soils was ascribed to dominant reduction (52–99%) coupled with secondary surface adsorption (1.2–48%) by organic substances. The maximum reduction capacity (Ym, 238 mg/kg) was found in an acidic brown soil with maize stalk amendment, secondly, with peanut shell amendment (Ym, 231 mg/kg). Their biochars presented a weaker capacity in reducing Cr(VI) to Cr(III) of soils than raw crop residues since carbonization accelerated the decomposition of oxygen-containing functional groups of organic substances. Soil properties, mainly soil pH, were negatively related to Cr(VI) reduction in soils remarkably, while concomitant anions in soils mainly the phosphate could compete with Cr(VI) for surfaces of soil particles and decrease Cr(VI) adsorption and subsequent reduction. The bioassay in pots with wheat seedlings further validated that maize stalk was a better organic substance for Cr(VI) immobilization and subsequent decrease of its bioavailability in contaminated soils than its biochar according to the results of wheat biomass and Cr contents in shoots and roots. Accordingly, to develop a cost-effective method for immobilizing Cr(VI) in contaminated soils, the raw maize stalk is more advantageous than the carbonaceous counterparts because no pyrolysis is required for the application.

Promotion effect with dispersed Fe-Ni-S catalyst to facilitate hydrogenolysis of lignite and heavy residue

Nickel sulfide is regarded as one of the most promising substitutes for the best-performing disposable molybdenum catalyst in the hydrogenolysis of lignite and heavy residue, but its practical application is hindered severely by insufficient catalytic activity and a prohibitively large dosage. Herein, we report that the issues of activity and cost of nickel sulfide can be addressed simultaneously by employing a combination of iron incorporation and a dispersing strategy via oil-soluble ligands. Motivated by first-principles calculations where iron incorporation in nickel sulfide would lead to a better activity towards the rate-limiting step of hydrogenolysis compared with nickel sulfide alone, we successfully prepared a well-dispersed Fe-Ni-S catalyst by coordinating active metal salts with carboxylate ligands and a subsequent essential sulfurization. The synthesized Fe-Ni-S catalyst outperformed not only the monometallic nickel catalyst but also the commercial molybdenum catalyst in the hydrogenolysis of lignite and heavy residue, and exhibited a high conversion efficiency, hydrogen consumption, hydrogen/carbon product atomic ratio, and dispersibility of solid residues, with an economic nickel dosage of as low as ~250 μg·g−1. Structural changes of raw coal and solid residues further confirmed the role of the Fe-Ni-S catalyst in facilitating the hydrogenolysis of lignite and heavy residue.

Multipath extraction and mitigation for high-rate multi-GNSS precise point positioning

Multipath effect on carrier-phase observation is one of the bottlenecks for mm-level applications when using precise point positioning (PPP). Hence, we extract the multipath directly from raw carrier-phase residuals of GPS, GLONASS, Galileo, and BDS, by using PPP technique. Although the residuals for one frequency assimilate the errors from other frequencies, which is caused by error adjustment by the least squares estimator, the primary component of residuals is multipath. The results indicate that the residuals between frequencies have a significant linear negative correlation and synchronous time lag for each system. Besides BDS Geostationary Earth Orbit satellites, the residuals for other satellites can establish accurate mathematic relationship between the frequencies. For GLONASS, the residuals of R1 frequency recovered from R2 frequency with the mathematical relationship are better than 0.1 mm accuracy, which means the effect of inter-frequency bias can be neglected. These regularities double-reduce the complexity of data processing. Based on the multipath distribution, we propose a modified Multipath Hemispherical Map model (M-MHM), which constructs grids from residuals and is divided into three equal-elevation angle parts with an optimal resolution 0.2° × 0.2° × 1° from numerous experiments. In addition, the multipath manifests great consistency among satellites for GPS, GLONASS, and Galileo systems when elevation angles are higher than 15°, while is more satellite dependent for BDS. Although GPS L1 frequency is identical to Galileo E1, the model still has some systematic bias between GPS and Galileo. Compared with sidereal filtering and original MHM model, the M-MHM brings the highest improvement in both residual variance reduction and positioning accuracy. The positioning accuracy is on average 12% improvement compared to MHM and 29% improvement compared to SF. For four systems combined solutions with the M-MHM model, can reach an accuracy of 0.75, 0.55, and 2.08 cm in the east, north, and up components.

Degradation of antibiotics and inactivation of antibiotic resistance genes (ARGs) in Cephalosporin C fermentation residues using ionizing radiation, ozonation and thermal treatment

In present work, the degradation of antibiotic and inactivation of antibiotic resistance genes (ARGs) in cephalosporin C fermentation (CEPF) residues were performed using ionizing radiation, ozonation and thermal treatment. The results showed that the three treatment methods could degrade cephalosporin C effectively, with the removal efficiency of 85.5% for radiation at dose of 100 kGy, 79.9% for ozonation at dosage of 5.2 g O3/L, and 71.9% and 87.3% for thermal treatment at 60 °C and 90 °C for 4 h. The cephalosporin resistance gene tolC was detected in the raw CEPF residues, and its abundance was decrease 74.2% by radiation, 64.6% by ozonation and 26.9%–37.1% by thermal treatment respectively. The presence of protein, glucose and acetate in the CEPF residues had inhibitive influence on the degradation of cephalosporin C by ionizing radiation, and the effect was more significant when the antibiotic concentration was lower. The total content of COD, polysaccharides and protein changed slightly after radiation and thermal treatment, while they were decreased greatly by ozonation. The primary techno-economic analysis showed that the operational cost of ionizing radiation by electron beam at 50 kGy ($5.2/m3) was comparable to thermal treatment ($4.3–7.9/m3), which was more economical than ozonation ($14.6/m3).

Soil amendment with nanoresidues from water treatment increases P adsorption in saline soils

Soil salinity is a major food issue in Egypt because salinity modifies P nutrient availability for crop plants. Residues from wastewater treatment can be added to soils for fertilization, but there is actually little knowledge on the effect of nanoresidues on P availability. Here, we mixed nanoresidues, obtained by grinding raw residues of water treatment, with soils of increasing salinity. We studied P adsorption and nanoresidue morphology. Results show that the addition of 0.5% of nanoresidues increases P adsorption from 9.43 to 93.46 µg g−1 for non-saline soils and from 12.02 to 153.85 µg g−1 for saline soils. Accordingly, the P Freundlich constant (KF) increased from 64.60 to 515.94 mL g−1 in the saline soil. Fourier transform infrared and X-ray diffraction data suggest that ligand exchange and precipitation are the main mechanisms.

Recovery of iron rich residues from integrated steel making process by hydrated lime/molasses pressurised cold agglomeration

This study aimed at verifying the technical feasibility of recovering and reusing several iron-rich residues from the steel production process through the production of briquettes that could potentially be reintroduced as a ferrous source into the converters during the transformation of hot metal into liquid steel. An experimental investigation was carried out on a pilot-scale briquetting plant that implements a pressurised cold agglomeration; 8 mixtures, with contents varying between 60 and 66% Basic Oxygen Furnace (BOF) slag and a maximum of 27% of stock-house dusts and process sludges were tested. In the context of the circular economy, beet molasses was added in varying amounts as a binder, along with cheaper hydrated lime. Experimental results showed how each mixture of recycled materials was able to make briquettes with a high average crushing resistance (73.3 daN for the best mixture, indicated as 2b mix). The X-ray powder patterns, chemical and scanning electron microscopy (SEM) characterization of 2b mix briquettes revealed clean raw residues as well as the presence of limited amount of unwanted compounds such as phosphorus and sulphur, due to the molasses used. By adopting a replacement ratio of 1 between commercial and 2b mix briquettes, a possible safe use of 2b mix briquettes in BOF converters has been estimated. As a lesson, although other investigations need to be carried out (i.e., the reduction disintegration index assessment), briquetting has proven to be effective. It must be intended as an integration rather than a replacement of the input materials generally used in the BOF converter.

New elements of water management

Modern water management goes presently through difficult processes of adaptation to new tatgetsstipulated by the needs of sustainable development. The process of change requires constantwidening of necessary knowledge and activitiy of engineers and scientists dealing with watermanagement. New targets require more itegrated actions, involving also new subject areas that areonly indirectly connected with traditional water management issues. To these belongs, forexample, management of raw materials, products and residuals, problems of soil pollution andresulting chemical contamination of agricultural products, presence of contaminants in food,influencing helth of population. Simultaneously, traditional goals of water management must bealso be fulfilled while costs of maintenance and renovation of oldering water supply and sanitarysystems increase parallel with age of constructions.Sustainable develpment postulates require actions towards preservation and gradual improvementof water quality in local and regional surface- and groundwater reservoirs in all regions,protection of agricultural soils, forests and other ecological systems such as weltands, medows,rivers and lakes that constitute a base for maintaining biological diversity and, simultaneously, forfood production and recreation of population in villages and cities. It may be notted that there is ageneral trend to widen the role of scientists and engineers dealing with water management toadress other, less typical areas, such as management of residuals, protection of rawmaterials andhealth protection of population. New understanding is growing among scientists and populationthat residuals, often classified as Agarbage=, Apollution:or Asolid weaste= may also constitutenew valuable resnources, it may be visualized by following symmetrical equation:Pollution = lost resources = pollutionBeginning with consideration of pollution problems one will arrive to the problem oflost naturalresources. Starting with a problem of inefective use and lost natural resources, one will arrve tothe problem of environmental pollution.

Heating rate effects on pyrolysis, gasification and combustion of olive waste

Pyrolysis, combustion and gasification of solid residues from olive oil processing were investigated. The raw solid residue (RS) contains moisture (21.5%) and residual oil (6.4%). Therefore, from RS, raw samples without water (RSWW) and without oil (RSWO) were produced. Thermal analyses of samples were performed at different heating rates over a temperature range of 150–1050 °C. Pyrolysis behavior of the sample was studied in an argon atmosphere, whereas the combustion and gasification studies were conducted in oxygen and steam atmospheres, respectively. The effects of heating rate on the reaction rate and gas evolution were analyzed. Thermal degradation of RS showed that nearly 90% of the conversion occurred at below 700 °C. Gases produced in the three processes mainly consisted of hydrogen, hydrocarbons and carbon oxides. Alcohols and sulfur compounds were also detected in the temperature range of 300 to 500 °C for pyrolysis. Activation energies were determined from non-isothermal multi-heating rate thermogravimetric measurements. The variation in gas evolution was observed between the samples during gasification.

Advanced Oxidation Processes to the Remediation of Liquid Residue from the Thermal Treatment of Oily Sludge

This work reports the remediation of a liquid residue derived from the thermal treatment of petrochemical residues by advanced oxidation processes. Firstly, degradation studies of phenol aqueous solutions by heterogeneous photocatalysis, Fenton, and photo-Fenton were conducted. Fenton processes showed a higher efficiency, mainly in the UVA photo-assisted mode (94% in 3 min), and henceforward it was chosen for the remediation of the residue. However, the high organic load of the raw residue (6,000 mg L-1 of chemical oxygen demand (COD)) limited the efficiency of the Fenton processes. Hence, the raw liquid residue was diluted with the scrubber residue, produced during the thermal treatment of the petrochemical residues, reducing the COD to values close to 2,000 mg L-1. The photo-Fenton treatment allowed the removal of approximately 95% of the COD load, decreasing the residual concentration of phenolic compounds from 213 to 0.5 mg L-1. At the same time, the concentration of BTEXs (benzene, toluene, ethylbenzene and xylene) were reduced to values lower than the limit of quantification (LOQ) of the chromatographic technique. Therefore, the photo-Fenton process is an efficient alternative to the remediation of residues with high complexity and with high COD values, like the ones obtained in the petrochemical industry.

RCEV heteroscedasticity test based on the studentized residuals

All the usual heteroscedasticity tests in the statistics and econometrics literature are based on raw residuals. Although the raw residuals are heteroscedastic, studentized residuals can still be homoscedastic. In this study, the version of Çelik’s RCEV heteroscedasticity test which is based on studentized residuals is introduced.