Academic literature on the topic 'Residue mixing'

(1) Background: Residue degradation plays a very important role in terrestrial ecosystems and residue mixing is the main factor affecting the degradation rates. However, in the agricultural systems, the effect of residue mixing on the degradation of pepper residues and the microbial community in pepper root residues is not clear. (2) Methods: In this study, we added different residues into soil by using double-layered nylon litterbags in culture bottles. The treatments including pepper root (P: Capsicum annuum L.), soybean [S: Glycine max (L.) Merr.] and maize (M: Zea mays L.) residue, as well as mixtures of soybean + pepper (SP), maize + pepper (MP), maize + soybean + pepper (MSP) mixtures. Litterbags were harvested after 7, 14, 28, and 56 days, respectively. Mass loss and nitrogen and phosphorus contents in pepper residue were quantified and bacterial and fungal community levels in pepper residues were analyzed using quantitative PCR and high throughput amplicon sequencing; (3) Results: The study showed that the mass loss and fungal community abundance of pepper root residue in mixtures were higher than P, except day 7. The phosphorus contents in MSP-P and MP-P were significantly lower than that for P at day 28 and day 56. Illumina MiSeq sequencing showed that the presence of maize residue significantly altered the microbial community composition of pepper root pepper. Day 56. (4) Conclusions: Our results suggest that residue mixing changed the microbial community abundance in pepper residue and promoted the degradation of pepper residues compared to pepper residue decomposition alone, especially for mixtures with soybean.

The actual problem of the oil refining industry is to improve the process of oxidation of heavy oil residues and the properties of oil bitumen. One way to solve the problem is to add modifiers. The addition of modifiers leads to an intensification of the oxidation process and an increase in the characteristics of the bituminous binders. The work aims to study the effect of adding rubber crumb on the process of vacuum residue oxidation and the properties of the obtained rubber-bitumen binders (RBB). The influence of the size of crumb rubber and its content, the mixing stage and oxidation modes on the properties of rubber-bitumen binders are determined. Vacuum residue from the Omsk oil refinery was used as a raw material, which was modified with crumb rubber with a dispersion of 0.6‒1.0 mm and less than 0.6 mm. The novelty of the research is the addition of crumb rubber to the vacuum residue and the oxidation process to obtain bitumen. The product of vacuum residue oxidation for 2 h at 260 °С with preliminary mixing of 2 wt.% crumb rubber with particle sizes less than 0.6 mm at 180 °С and additional mixing of 8 wt.% crumb rubber after oxidation corresponds to the brand of rubber-bitumen binder RBB 60/90. The rubber-bitumen binder is characterized by high elasticity and low Fraas point. Рrepared аsphalt concrete mixture based on RBB corresponded to type B according to physical and mechanical parameters. The complex shear modulus of the samples decreases with the temperature increase. Short-term aging resulted in increased shear modulus for all samples.

To investigate the effect of wave-induced mixing on the upper ocean structure, especially under typhoon conditions, an ocean-wave coupled model is used in this study. Two physical processes, wave-induced turbulence mixing and wave transport flux residue, are introduced. We select tropical cyclone (TC) Nepartak in the Northwest Pacific ocean as a TC example. The results show that during the TC period, the wave-induced turbulence mixing effectively increases the cooling area and cooling amplitude of the sea surface temperature (SST). The wave transport flux residue plays a positive role in reproducing the distribution of the SST cooling area. From the intercomparisons among experiments, it is also found that the wave-induced turbulence mixing has an important effect on the formation of mixed layer depth (MLD). The simulated maximum MLD is increased to 54 m and is only 1 m less than the observed value. The wave transport flux residue shows a dominant role in the mixed layer temperature (MLT) changing. The mean error of the MLT is reduced by 0.19 °C compared with the control experiment without wave mixing effects. The study shows that the effect of wave mixing should be included in the upper ocean structure modeling.

The innovative technology MELANGETM allows produce of the bitumen in one stage with the required properties, according to the technical request of the Customer, from the heavy oil residue basis on the use of physical and induced by them chemical processes. In this case, the main physical processes are heating and homogenization of various heavy residues upon heating, that is, mechanical mixing, almost to an ideal state, in parallel with the addition of a polymer capable of forming long spirals and chains in dispersed media. The experimental work was the basis for the trial production of bitumen according to the European standard BDS EN12591: 2009, which was successfully implemented using the MELANGETM technology at the LUKOIL Neftochim Burgas AD refinery (Burgas, Bulgaria). The heavy unreacted fluidized bed hydrocracking (VTB) residue of the Axens France H-oil process was used as feedstock. Based on the results of experimental work and the basis of confirmed data from the Customer, a patent of the Russian Federation No. 272118 " Method of producing road bitumen from a heavy residue" was issued. MELANGETM technology allows solving the problem of utilizing low-margin heavy oil residues, including unconverted residues from high conversion of oil residues, into high-margin products such as road bitumen and bituminous binders.

Abstract. To investigate how atmospheric aerosol particles interact with chemical composition of cloud droplets, a ground-based counterflow virtual impactor (GCVI) coupled with a real-time single-particle aerosol mass spectrometer (SPAMS) was used to assess the chemical composition and mixing state of individual cloud residue particles in the Nanling Mountains (1690 m a. s. l. ), southern China, in January 2016. The cloud residues were classified into nine particle types: aged elemental carbon (EC), potassium-rich (K-rich), amine, dust, Pb, Fe, organic carbon (OC), sodium-rich (Na-rich) and Other. The largest fraction of the total cloud residues was the aged EC type (49.3 %), followed by the K-rich type (33.9 %). Abundant aged EC cloud residues that mixed internally with inorganic salts were found in air masses from northerly polluted areas. The number fraction (NF) of the K-rich cloud residues increased within southwesterly air masses from fire activities in Southeast Asia. When air masses changed from northerly polluted areas to southwesterly ocean and livestock areas, the amine particles increased from 0.2 to 15.1 % of the total cloud residues. The dust, Fe, Pb, Na-rich and OC particle types had a low contribution (0.5–4.1 %) to the total cloud residues. Higher fraction of nitrate (88–89 %) was found in the dust and Na-rich cloud residues relative to sulfate (41–42 %) and ammonium (15–23 %). Higher intensity of nitrate was found in the cloud residues relative to the ambient particles. Compared with nonactivated particles, nitrate intensity decreased in all cloud residues except for dust type. To our knowledge, this study is the first report on in situ observation of the chemical composition and mixing state of individual cloud residue particles in China.

Vacuum residue of Jumboor crude oil above 773 K of specific gravity 1.105 and 6. I wt% sulfur , was treated with commercial pentane &hexane fractions for preparing deasphaltened oil (DAO) suitable for hydrodesulphurization process. Solvent deasphaltening was examined with mixing time 0.25 to 4 h and solvent to oil ratio 4 to 15 ml : 1g at different temperatures . The asphaltenes yield was decreased with increasing mixing time and increased with increasing solvent to oil ratio . Hexane deasphaltened oil hydrotreated on presulfided commercial cobalt-molybdenum alumina catalyst at specified operating conditions in a trickle bed reactor . The hydrotreating process applied at a range of temperatures varied from 623 to 698 K, liquid hourly space velocity (LHSV) from 0.7 to 2.2 h-1 ,H2/oil ratio about 300 liter/liter and hydrogen pressure was 4 Mpa . The results of hydrotreating process indicate high sulfur and metal removal with decreasing LHSV as well as high temperature applied . The kinetic of hydrodesulphurization and demetalization reactions followed 2nd and 1st order reactions respectively .

The need for biomass as an alternative source for energy purposes points toward oil palm fruit residues (Elaeis guineensis Jacq.) as an attractive solution. Oil palm industry residue, such as oil palm empty fruit bunch (EFB) composites and mesocarp fiber (PMF), have a high gross calorific value and could help countries meet their energy demands. However, information concerning physical, mechanical, and energy characteristics of agro-pellets made from mixtures of oil palm residue with pine sawdust, is not available. In this research, oil palm residues were mixed at ratios of 100:0, 80:20, 60:40, 40:60, 20:80, and 0:100 with pine sawdust, and were chemically analyzed. Agro-pellets from mixtures were tested on their physical and mechanical properties, and the relationship of these properties with the chemical composition of oil palm residue mixtures was determined. Normality distribution tests of the variables were performed using the Kolmogorov–Smirnov test. Normal variables were analyzed through one-way ANOVA tests. When differences were found, they were validated using the Tukey’s honestly significant difference (HSD) test and were considered statistically significant at p ≤ 0.05. Data not normally distributed were analyzed by the Kruskal–Wallis test. Bulk density, particle density, and gross calorific value of agro-pellets (from mixing 80:20 oil palm residues with pine sawdust) were statistically higher (p < 0.05) to agro-pellets of 100% oil palm residues. Adding pine sawdust to oil palm residues increases some mechanical agro-pellet properties. Addition of pine sawdust to oil palm residues acts to increase some mechanical properties of agro-pellets.

The use rate of the vegetable-residue is low which pollution-free processing does not reach the designated position. In order to resolve the problem of vegetable residues treatment, the research focus on transforming from vegetable-residue to feed for livestock and poultry combining with its characteristics of big water content and strong seasonality. Firstly, the vegetable cakes with about 45% moisture content were made of vegetable-residue by cleaning, beating, pressure filtration, batching, mixing, granulating, cooling and packaging. The orthogonal experiment method was used to optimize the addition amount of bentonite, wheat middling, powdered rice hulls, binder and corn protein powder into vegetables particle roughage of poultry and vegetables honeycomb roughage of livestock from vegetable cakes which selected the forming ratio as the indicator. The results showed that when the addition amount of bentonite was 20%, wheat middling was 20%, powdered rice hulls was 20%, corn protein powder was 5%, the vegetables particle roughage had the best forming ratio, while the addition amount of bentonite 12.5%, wheat middling 10%, powdered rice hulls 15%, corn protein powder 3%, binder 2%, the livestock vegetables honeycomb roughage had the best forming ratio. The results would provide the references for vegetable-residue industrial treatment.

The increased use of fossil fuels during the last centuries has caused elevated levels of carbon dioxide in the atmosphere. There is significant evidence that this is the cause of global warming. To mitigate the global warming, measures has to be taken to use renewable fuels and make processes more efficient. Catalytic gasification and downstream upgrading of synthesis gas is a promising technology for biofuel production, where previous research in black liquor gasification is currently expanding into a wider fuel feedstock. This work focuses on co-gasification of black liquor and by-products from other biofuel production technologies. The interesting by-products were crude glycerol from biodiesel production and spruce fermentation residue from ethanol production. The main goals were to study if the fuels can mix homogeneously and study the char reactivity. CO2 char gasification for mixtures of black liquor and glycerol or fermentation residue respectively was studied using thermogravimetric analysis (TGA) for four temperatures between 750°C and 900°C. The results show that glycerol can be mixed in all proportions with black liquor and indicate that the char reactivity is unchanged. The sustained char reactivity for blends is attributed to the volatility of glycerol. The fermentation residue does not produce a homogeneous mixture with black liquor and the char is less reactive. More studies should be performed to further elucidate the validity of the results.

Road slips are common in Northland Allochthon residual clay soil, and are commonly mitigated using deep soil mixing (DSM). A deficiency in laboratory investigations on Northland Allochthon residual clay and a need for a better understanding of the numerical modelling of DSM columns used to mitigate unstable slopes in this soil type is evident in literature, and has been highlighted by practitioners. This research has aimed to fill aspects of these deficiencies. Field testing and classification tests have provided insight into how the soil varies between sites and with depth, and how in situ testing methods compare to one another. Field testing has also demonstrated that soil property changes around DSM columns have been shown to exist through seismic flat plate dilatometer testing before and after column installation, which has not previously been proven using an in situ method. This is important for practitioners who use DSM to demonstrate the additional soil improvements provided by the columns. The testing of reconstituted soil is fundamental in examining soil behaviour, and this study is the first to examine the triaxial behaviour of reconstituted specimens of Northland Allochthon soil. Laboratory triaxial testing and oedometer testing have allowed for a normalized comparison of the intact strength of Northland Allochthon residual clay soil to its reconstituted state. This work provides an answer to the important question regarding the role of soil structure in this soil type. It was revealed that soil structure results in increased shear strength of the soil, and that this increase is primarily cohesive in nature. The near coincidence of the post-rupture strength of intact specimens with the critical state angle of internal shearing resistance provides support for its use in examining first time slope failures in this soil type. This is an important finding for practitioners, as it demonstrates the value of testing reconstituted specimens, which are much easier to obtain than high quality intact specimens. In addition, relationships between the plasticity index (PI) of the soil and certain soil parameters (and soil behaviour) have been demonstrated to be relevant and useful for this soil type. Soil properties acquired in this study were tabulated along with those from other field sites in Northland Allochthon soil. It was found that there is significant variation between field sites, likely due to varying degrees of weathering, which is an important consideration for practitioners dealing with this soil type. A brief examination of constitutive models for representation of Northland Allochthon residual clay soil have shown that several different models can sufficiently represent the behaviour of this soil. The Mohr-Coulomb model was selected for use in subsequent finite element numerical models. A case study of a road slip at a field site in Northland Allochthon residual clay soil, mitigated using DSM columns, revealed that the use of a pre-existing slip surface after first time failure leads to an improved match between observed field behaviour and the behaviour of the slope as exhibited in a numerical model. This type of failure mechanism has not been previously examined in this soil type, and this case study demonstrates it is a useful approach that should be considered when dealing with second time failure in Northland Allochthon slopes. This numerical model also introduces the replacement ratio method (RRM), a technique used to represent the three dimensional (3D) geometry of the DSM columns in the more commonly used two dimensional (2D) analysis. Examination of laterally loaded DSM columns in plan view, which has not previously been performed in the context of DSM columns, has illustrated how installation effects and column shape influence load displacement curves, and demonstrates the effects of soil arching. This analysis provides practitioners with evidence that improved soil property changes, found to occur around DSM columns, lead to improved DSM column performance. A simplified 3D numerical model of laterally loaded DSM columns, which builds on the ideas developed in the previous two 2D models, has been compared to an identical 2D model. It is shown that the commonly used RRM results in an overestimation of the resisting force provided by the columns as compared to the 3D model. However, this does not necessarily imply that the use of the RRM in an analysis will always result in a safe slope. The degree to which its use will affect the results will depend on the slope geometry, location of the DSM columns, and the type of analysis performed (i.e. factor of safety or deformation based). A modification to the RRM has been proposed. It is recommended that when the DSM column diameter and soil properties are similar to those used in this study, the MRRM developed in this study should be utilized. In circumstances where they differ, it is recommended that practitioners perform a sensitivity analysis using the MRRM developed here as a basis for modifying the RRM in order to determine the extent to which their results are influenced. If the influence is significant, the use of a 3D model should be considered.

La marée océanique a longtemps été considérée comme un phénomène haute fréquence dont la zone d'influence se limitait aux plateaux continentaux. Ainsi, la marée n'apparaissait pas susceptible d'interagir sur la circulation océanique grande échelle et in fine sur la dynamique basse fréquence du climat. Ce n'est qu'à la fin des années 1990, lorsque la mesure altimétrique et les solutions hydrodynamiques globales de marées ont atteint une précision centimétrique, qu'une connexion entre les marées et le climat est devenue envisageable. Dans cette perspective, l'objectif de cette étude est d'explorer quels sont les effets de la marée sur la circulation océanique grande échelle. Ces effets ont lieu à travers deux processus physiques essentiels liés à la marée : (i) sa dynamique fortement non-linéaire et (ii) la dissipation de son énergie en plein océan, sous la forme de mélange vertical ou de chaleur.
Pour examiner chacun de ces aspects, la méthode retenue consiste à paramétriser les effets de la marée dans un modèle tridimensionnel de circulation générale océanique (OGCM) dédié au climat : NEMO. Pour ce faire nous utilisons les sorties 'off line' d'un modèle hydrodynamique bidimensionnel dédié à la marée : MOG2D-G. Dans un premier temps nous déterminons et nous décrivons pour la première fois une carte de la circulation résiduelle de marée (CRM) mondiale générée par la dynamique non-linéaire de la marée. Cette CRM obtenue par l'intermédiaire de MOG2D-G est alors introduite sous la forme d'un forçage extérieur dans l'OGCM NEMO. Dans un second temps, nous examinons la dissipation de l'énergie des marées. Tout d'abord nous quantifions la fraction de l'énergie de marée qui est dissipée en chaleur, ceci afin de déterminer si, à l'instar du flux géothermal, elle est susceptible de jouer un rôle important sur la circulation abyssale. Après avoir écarté cette possibilité, nous considérons la fraction d'énergie de marée qui se dissipe localement en mélange vertical via les ondes internes : le "tidal mixing" (TM). Le TM résulte d'un transfert d'énergie du mode barotope vers les modes baroclines. Ce transfert est diagnostiqué grâce au modèle MOG2D-G et intégré dans NEMO par l'intermédiaire d'une paramétrisation du mélange turbulent vertical.
Nous concluons : (i) que l'effet des marées sur la circulation océanique grande échelle et in fine sur le climat ne peut être significatif qu'à travers le TM, (ii) que l'introduction du TM local dans les OGCM est essentielle pour représenter correctement le transport des masses d'eaux abyssales et (iii) qu'il est désormais crucial de considérer le TM engendré loin du site de génération des ondes internes

Salinity is a major constraint to crop production and also contributes to land degradation, particularly in arid and semiarid regions. Salinity has negative effects on soil microorganisms, reducing soil respiration, microbial biomass and microbial diversity. One of the main reasons for the negative impact of salinity is the low osmotic potential induced by high salt concentrations in the soil solution which reduces water uptake into cells and can cause water loss from cells. Some microorganisms can adapt to salinity by accumulation of osmolytes which is a significant metabolic burden. Rapidly decomposable plant residues contain high concentrations of easily available compounds which can be utilised by many soil microbes. Slowly decomposable residues on the other hand contain complex compounds which can only be utilised by few microbes, those capable of releasing specialised enzymes to break down these compounds. If salinity inhibits or kills some microbes, the decomposition of rapidly decomposable residues may be less affected than that of slowly decomposable residues because the loss of sensitive microbes can be compensated by a larger number of microbes with the former compared to the latter. If this is true, microbial activity after addition of slowly decomposable residues (high in lignin content and C/N ratio and low in water soluble carbon) should decrease more strongly with increasing salinity than after addition of rapidly decomposable residues. However, most previous studies on respiration in saline soils only used one or two types of plant residues (e.g. cereal or legume shoots). A further factor that may influence the impact of salinity on soil respiration is the frequency of residue addition. Frequent residue addition may provide soil microbes with a continuous supply of nutrients and therefore improve salinity tolerance compared to a single addition where easily available compounds are rapidly depleted. These two assumptions have not been systematically investigated. The aim of this project was to investigate the effect of the chemical composition of added residues, mixing of residues and addition frequency on soil respiration and microbial biomass in soils with different salinity. Three studies were carried out to address the aims in non-saline soil and naturally saline soils with different salinity levels. The aim of the first study was to investigate the impact of salinity on respiration in soil amended with residues differing in chemical composition (lignin concentration, water soluble organic carbon and C/N ratio). Three incubation experiments were conducted in this study. In the first experiment various residue types (shoots of wheat, canola, saltbush and kikuyu, saw dust, eucalyptus leaves) differing in C/N ratio, lignin and water extractable organic carbon concentration, were applied at 2% w/w to a non-saline soil (EC₁﹕₅, 0.1 dS m⁻¹) and three naturally saline soils with EC₁﹕₅ 1, 2.5 and 3.3 dS m⁻¹. Cumulative respiration decreased with increasing salinity but the negative effect of salinity was different among residues. Compared to non-saline soil, respiration was decreased by 20% at EC₁﹕₅ 0.3 dS m⁻¹ when slowly decomposable residues (saw dust or canola shoots) were added, but at EC₁﹕₅ 4 dS m⁻¹ when amended with a rapidly decomposable residue (saltbush). In the second experiment, the influence of residue C/N ratio and lignin content on soil respiration in saline soils was investigated. Two residues (canola and saw dust) with high C/N ratios but different lignin content were used. The C/N ratio was adjusted to between 20 and 80 by adding ammonium sulfate. Increasing salinity had smaller impact on cumulative respiration after addition of residues with C/N ratio 20 or 40 compared to residues with higher C/N ratio. In the third experiment, the effect of the concentration of water-soluble organic C (WEOC) of the residues was determined. WEOC was partially removed by leaching from two residues with high WEOC content (eucalypt leaves and saltbush shoots). Partial WEOC removal decreased cumulative respiration in saline soil compared to the original residues, but increased the negative effect of salinity on respiration only with saltbush shoots. The second study was conducted using the four soils from the first study (EC₁﹕₅, 0.1, 1, 2.5 and 3.3 dS m⁻¹) to compare the impact of single and multiple additions of residues that differ in decomposability on the response of soil respiration to increasing salinity. Two residues with distinct decomposability were used; kikuyu with 19 C/N ratio (rapidly decomposable) and canola with 82 C/N ratio (slowly decomposable). Both residues were added once or 2-4 times (on days 0, 14, 28 and 42) with a total addition of 10 g C kg⁻¹ soil and incubated for 56 days. Compared to a single addition, repeated addition of the rapidly decomposable residue reduced the negative effect of salinity on cumulative respiration, but this was not the case with slowly decomposable residues. The third study was carried out to investigate the effect of the proportion of rapidly and slowly decomposable residues in a mixture on the impact of salinity on soil respiration. This study included two experiments with two residues differing in decomposability (slowly decomposable saw dust and rapidly decomposable kikuyu grass). In the first experiment, both residues were added alone and in mixtures with different ratios into four soils having EC₁﹕₅ 0.1, 1.0, 2.5 and 3.3 dS m⁻¹. The addition of 25% of rapidly decomposable residues in mixture with slowly decomposable residues was sufficient to decrease the negative impact of salinity on cumulative respiration compared to the slowly decomposable residue alone. In the second experiment, three soils were used (EC₁﹕₅ 0.1, 1.0 and 2.5 dS m⁻¹), residues were added once or 3 times (on days 0, 14 and 28) to achieve a total of 10 g C kg⁻¹ soil either with sawdust alone, kikuyu alone or both where final proportion of kikuyu was 25%, but the order in which the residues were applied differed The negative effect of salinity on cumulative respiration was smaller when the rapidly decomposable residue was added early, that is when the soil contained small amounts of slowly decomposable residues. Salinity reduced soil respiration to a greater extent in treatments where rapidly decomposable residue was added to soil containing larger amounts of slowly decomposable residues. It is concluded that rapidly decomposable residues can alleviate salinity stress to soil microbes even if they make up only a small proportion of the residues added. By promoting greater microbial activity in saline soils and providing nutrients, rapidly decomposable residues could also improve plant growth through increased nutrient availability.
Thesis (Ph.D.) (Research by Publication) -- University of Adelaide, School of Agriculture, Food and Wine, 2015.

Organic matter decomposition in terrestrial system is of vital importance for nutrient cycling and ecosystem function. Soil microorganisms are the key drivers of decomposition which regulates the availability of inorganic nutrients through immobilisation and mineralisation. The size of the soil organic C pool is twice that of C in the atmosphere and more than twice of that in vegetation. Thus, organic matter decomposition in soil greatly influences the C flux between soil and the atmosphere. Therefore understanding factors influencing organic matter decomposition is important for climate change mitigation and soil fertility. In this thesis, the effects of residue mixing, removal of water-extractable organic C, clay subsoil addition to sandy soil and drying and rewetting on decomposition were investigated. Organic matter decomposition is influenced by both internal and environmental factors. Plant residues are an important source of soil organic C and decomposition of plant residues has been studied extensively. However, residues from different species or above- and below-ground residues are often mixed and less is known about factors influencing decomposition of residue mixtures. Shoot and root residues of three Australian native perennial grass species [Wallaby grass (Danthonia sp); Stipa sp and Kangaroo grass (Themeda triandra)] and barley (Hordeum vulgare L.) were mixed to create nine different residue mixtures (1:1 mixture). Soil respiration was measured over 18 days. Cumulative respiration in residue mixtures differed from the expected value (average of cumulative respiration of individual residues) in most cases with synergistic interactions occurring in 56 % of the mixtures (expected < measured value), antagonism in 22 % (expected > measured value). Synergism occurred when residues with relative similar decomposition rate were mixed, while antagonism occurred when the decomposition rate of individual residues differed strongly. Furthermore, a negative correlation was found between the change in microbial biomass C (MBC) and available N concentration between the start of the experiment and day 18 and cumulative respiration on day 18. The interaction with respect to cumulative respiration was not reflected in MBC and available N concentrations. Cumulative respiration and MBC concentration were greater in soil amended with residues with higher water-extractable organic C (WEOC) concentration, compared to those with lower WEOC concentration, either individually or as in mixtures. Between 2 and 30 % of organic C in residues is water-extractable and its importance in stimulating decomposition has been shown previously. Water-extractable organic C can be leached by heavy rainfall or irrigation, but little is known about the effect of addition of residues from which the WEOC was removed by extraction or leaching on microbial activity and biomass. Shoot residues of barley (Hordeum vulgare L.) were extracted five times for maximal removal of WEOC or were leached up to eight times to partially remove WEOC. Maximum WEOC removal decreased both soil respiration and MBC concentration in the first week, but MBC concentration at the end of the experiment was greater with extracted residues compared to the original residues. With leached residues, partial removal also reduced respiration rate in the first 10 days. However, MBC concentration was greatest with residue leached eight times, suggesting great substrates utilisation efficiency. In South Australia a large area of land is covered by sandy soils (3.2 million ha), with a heavy textured soil underneath, so called ‘duplex soil’. Due to the lack of binding sites for organic matter and nutrients and large pore size, sandy soils are often characterised by low organic matter content, low nutrient and water retention capacity and rapid organic matter decomposition. Addition of clay-rich subsoil to sandy soil has been shown to increase crop yield and water retention in sandy soils. Additionally, clay particles could bind organic matter. However, little is known about the effect of clay subsoil addition to sandy soil on soil respiration after addition of residue mixtures. Clay subsoil was added to a sandy top soil at 10 and 30 % (w/w). Residues of barley (Hordeum vulgare L.) and two native perennial grass species (Danthonia sp and Themeda triandra) were added individually or as 1:1 mixture. Increasing clay addition decreased cumulative respiration and extractable C concentration in soil with individual residues and mixtures. No interaction was observed in terms of cumulative respiration in sandy soil alone, but at addition of 10 % clay subsoil, antagonism occurred in two residue mixtures, and at 30 % clay addition synergism occurred in one of the mixtures. It can be concluded that clay soil addition to sandy soil does not only alter decomposition rate but also interactions in residue mixtures. In Mediterranean climate such as in South Australia long periods of dry and hot weather are interrupted by occasional rainfall or irrigation. Although the effect of drying and rewetting (DRW) has been studied extensively, the factors determining the respiration flush upon rewetting and total cumulative respiration are not fully understood. A sandy soil amended with different proportion of clay subsoil (0, 5, 10, 20, 30, and 40 %) was exposed to a single DRW event. Expressed per g soil, cumulative respiration in the constantly moist control (CM) decreased with increasing clay soil addition rate, but cumulative respiration in the DRW treatment did not vary among clay soil treatments. However, when expressed per g total organic C (TOC), cumulative respiration in the DRW treatment increased with increasing clay subsoil addition rate. Addition of clay subsoil increased water retention capacity during drying, thus microbial activity. The respiration flush one day after rewetting was greater than the respiration rate in CM only in treatments with 20-40 % clay addition rate. The response of respiration to DRW may be influenced by land management due to its effect on the soil organic C pool and differ between soil size fractions. An incubation experiment was conducted with soils collected from two plots with a long history of different management (wheat-fallow rotation and permanent pasture). The soils were sieved to 4-10 mm and <2 mm to obtain two size factions. There were five moisture treatments with the same length (48 days). The CM treatment was maintained at 50 % of maximum water-holding capacity (WHC) throughout. In the DRW treatments, the number of dry and moist days was equal but the number of DRW events ranged from one to four (1 to 4DRW). Cumulative respiration per g TOC at the end of the experiment was greater in the <2 mm than in the 4-10 mm fraction in both soils and was highest in CM and 1DRW. In wheat soil, cumulative respiration decreased from 1DRW to 3DRW, whereas it decreased only between 2 to 3DRW in pasture soil. Cumulative respiration in the second moist period was greater in 3DRW than in 2DRW (8 and 12 prior moist days) whereas cumulative respiration in the third moist period was greater in 4DRW than in 3DRW (12 and 16 prior moist days). It can be concluded that the response of respiration to drying and rewetting is more strongly influenced by management than size fraction. Cumulative respiration upon rewetting is influenced not only by the number of DRW cycles but also the number of moist days prior to rewetting. Three incubation experiments were carried out to assess the relationship between cumulative respiration per g TOC and the number of moist or dry days with the two soils used in the previous experiment. In the first experiment, the CM and DRW treatments had the same total length (10 days) with different proportions of moist and dry days in the DRW treatments. The second and third experiment had DRW cycles of dry and moist period of equal length with one cycle in Experiment 2 and two cycles in Experiment 3. Soil in the CM was maintained at 50 % of WHC throughout for all experiments. Total cumulative respiration per g TOC was greater in wheat than in pasture soil which can be explained by the greater proportion of particulate organic matter in the former. In the first experiment, cumulative respiration in the dry period was not influenced by the number of dry days, but cumulative respiration in moist period increased with number of moist days. Total cumulative respiration in the DRW cycle was negatively correlated with the number of dry days and positively correlated with the number of moist days. Cumulative respiration in DRW treatments was lower than in CM when the proportion of moist days was less than 50 % of the total length with the difference becoming greater with decreasing proportion of moist days. In both the second and the third experiment, total cumulative respiration increased with increasing number of days with a greater increase in CM than in DRW treatments. When subjected to two DRW cycles in the third experiment, total cumulative respiration in each DRW cycle was also positively correlated with the number of moist days with the slope greater in first than in the second DRW cycle. In conclusion, cumulative respiration in DRW cycles is mainly a function of the number or proportion of moist days and little influenced by soil management. An incubation experiment was conducted with the soil from the wheat-fallow rotation to determine the influence of number of dry and moist days and their distribution in two DRW cycles on respiration rate and cumulative respiration in each DRW cycle. The number of moist and dry days ranged in either the first or second DRW cycle between 10 and 35. The constantly moist treatments were maintained at 70 % of WHC throughout. Cumulative respiration in CM was greater than that in DRW treatments with the difference greater in treatments with varying number of dry days than those with varying number of moist days. Cumulative respiration in the dry period differed little among DRW treatments. The flush of respiration upon rewetting increased with number of prior dry days. Respiration rates in the moist period of the first cycle were higher than in the second cycle only up to 17 days, indicating that the effect of prior substrate utilisation in 5 moist days in the first cycle is limited to first 17 days in the moist period of second cycle. Cumulative respiration in the moist period increased with the number of prior dry or moist days with the increase greater in treatments varying in number of moist days than those varying in number of dry days. Cumulative respiration was greater when the number of moist or dry days varied in the first than in the second cycle. It is concluded that the number of dry days influences the size of the respiration flush after rewetting, while the number and distribution of moist days affect cumulative respiration. To summarise, the studies described in this thesis showed: • Cumulative respiration in residue mixtures relative to that of the individual residues depends on residue type and soil clay content. • Removal of WEOC from residues reduces initial respiration rates but not always cumulative respiration. • Addition of clay to sandy soil not only reduces cumulative respiration but also alters respiration in dry and moist periods of DRW cycles. • Cumulative respiration in DRW treatments is mainly influenced by the length of the moist period: (i) total length of the moist period determines total cumulative respiration at the end of the DRW treatments, and (ii) number of prior moist days influences respiration in the subsequent cycles.
Thesis (Ph.D.) -- University of Adelaide, School of Agriculture, Food and Wine, 2015

Thesis (M.S.)--University of Wisconsin--Madison, 2004.
Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 141-143).

碩士
國立嘉義大學
森林暨自然資源研究所
94
The demand for wood products has been increasing for recent years, resulting in much more wood wastes. Bark can be regarded as an utilization indicator of overall wood wastes. Bark from some species contains abundant lignin and poly-phenols such as tannin, which can be used for making bio-based adhesives and eliminating free formaldehyde emission. In addition, in order to make the most of wood waste, various types of particleboard can be produced by mixing bark and wood particle in different ratios. In this study, wood particle/bark mixtures were made in different ratios. Several types of particleboard were produced, according to the following parameters：glue content, bark/wood particle size, bark mixed ratio and additive(e.g. furfural) . To evaluate the feasibility of the mass production of particleboard made of radiata pine bark/ wood particle, density (D), moisture content (MC), internal bond strength (IB), bending strength (BS), thickness swelling (TS), and the free formaldehyde emission were investigated. The results showed that the compression ratio of the particle board is inversely correlated with the proportion of the bark mixed in the boards. The density of single-layered particleboard ranged from 0.63 to 0.65 g/cm3 and the moisture content ranged from 7.99 to 9.02%. The thickness swelling increased as the glue content and bark size decreased. Increased bark proportion also resulted in increased thickness swelling. Free formaldehyde emission decreased as bark mixed ratio increased and glue content decreased. The amount of free formaldehyde from most of our boards meets the requirement described in the E1 criterion from CNS 2215 standards for normal particleboard. Internal bond strength decreased as glue content decreased and bark size got finer; increased bark proportion also resulted in decreased internal bond strength. The modulus of elasticity was slightly increased when the board manufactured under mixing 5% bark, but decreased when the board manufactured under mixing over decreased 10% of bark. The modulus of elasticity also decreased as glue content and bark size got finer. The modulus of rupture was slightly increased when the board manufactured under mixing 5% bark (－60＋100 mesh), but it decreased when the board manufactured under mixing over 10% of bark. The modulus of rupture also decreased as glue content and bark size got finer. The mechanical strength of the board could be improved by increasing the furfural additives according to the increased bark proportion. After being tested with CNS 2215 standards for normal particle board, all the boards manufactured in the study did not meet the MOE standard, and a small number of the boards did not meet the type 8 criterion; however, most of our boards are of a quality higher than type 8 criterion, some of them even having a quality higher than type 13 criterion.

碩士
國立交通大學
環境工程所
90
Although water treatment residual (WTR) contains no hazardous chemicals, the increasing volume generated from water treatment has reached unmanageable level. The soil excavated from the ground before construction, essentially clay, is another big problem in this island. Currently, landfill disposal is the main waste management method for these two waste soils, which is not a practical solution because of high cost of transportation and the scarcity in land. Due to the nature of WTR and excavation soil (ES), recycling and reuse in construction materials has become a more popular way of treating them. In this study, sintering processes were attempted to make the waste soils into building brick and artificial aggregate. First, the chemical compositions of WTR and ES were analyzed using ICP-AES and the mineralogical composition was determined with X-ray diffraction. The chemical composition of ES was similar to clay. WTR had more Al2O3 and less SiO2 than ES. The compression strength result suggested that sintering temperature was critical in brick-making. Various amount of WTR was added to ES before sintering, and the sintering behaviors of the products from different sintering conditions were monitored. When sintered at 1050℃, the brick from samples containing 30% WTR could reach around 200 kg/cm2 compression strength. Bricks made from mixtures containing 15% WTR could reach 100 kg/cm2 compression strength when sintered at 950℃. The specific gravities of artificial aggregates sintered at 1000℃, 1050℃, and 1100℃ were all less than 2 kg/cm3. Results of specific gravity, water absorption, and compression strength suggested that WTR artificial aggregate could meet the general requirement for lightweight aggregates.

ABSTRACT This study investigates the effectiveness of chlorine as the disinfectant employed in the wastewater treatment plants operated by Lepelle Northern Water and generally within most municipal wastewater treatment works. The literature review reveals that much of the chlorine demand is ultimately wasted, since reactions competing with the disinfection process results in the formation of chloramines and other by-products not related to chlorine’s primary purpose of inactivating micro-organisms in the water. The investigation focused on the following aspects:  The impact of chlorine and wastewater contact time and chlorine residual concentration on micro-organism inactivation while reducing chlorine dose and aiming not to meet chlorine demand.  The impact of mixing on the effective disinfection of effluent at the point of chlorination. Literature shows that although various alternatives to chlorine are available, chlorine remains user-friendly and the cost-effective option for the disinfection of wastewater. The formation of chlorine residual in sewage effluent for inactivation of bacteria and prevention of regrowth is not as necessary as it is in drinking water systems where the chlorine residual has to be maintained throughout the distribution system. It is therefore a wasteful exercise to satisfy the chlorine demand in wastewater (sewage) effluent discharged into water courses. It is also worth noting that the only purpose of chlorine in wastewater effluent disinfection is to inactivate microorganisms. There is no need to prevent the recontamination of water since the effluent in most municipal sewage treatment plants are immediately discharged into a water course and the chlorine residual in the effluent must not be detected since it is toxic to aquatic life. This study therefore examines the potential disinfection effectiveness of chlorine without meeting chlorine demand or reaching breakpoint chlorination and mixing at the point of chlorination. The results obtained from a full-scale wastewater treatment plant effluent quality monitoring programme were used as baseline information and reference for this study. By comparing the observed micro-organism (that is; E. coli) inactivation in the full-scale chlorine systems with E. coli inactivation determined under laboratory conditions, it is conclusive in the literature that chlorination in practice appears to be much less effective than could be expected under laboratory conditions. In the literature, one study shows that suboptimal hydraulics of full-scale systems are known to reduce the efficacy of inactivation in practice. However, this study indicates that when mixing is applied at the point of chlorination, significant and comparable inactivation can be achieved at a full-scale and at a laboratory scale. This was confirmed in another study which reported rapid initial E. coli inactivation upon contact with free chlorine. Therefore, when a specific optimal mixing regime is determined and applied at the point of chlorination, effective E. coli inactivation in the water is achieved irrespective of the kinetics applicable either at a laboratory scale or in a full-scale system. This study examines the potential disinfection effectiveness of chlorine without meeting chlorine demand or reaching breakpoint chlorination and mixing at the point of chlorination. The results obtained shows that E. coli inactivation occur at two rates, an initial rapid kill followed by a slower kill. For each applied chlorine dose, the highest inactivation rate was obtained during the first one minute of contact time, which could be due to the presence of free chlorine residual that had not yet reacted with chlorine demanding substances (organics and chemicals). The subsequent slower kill can possibly be attributed to the formation of less potent combined chlorine residual as a result of reactions between free chlorine residual and chlorine demanding substances (mainly NH3). This study revealed that rapid mixing of chlorine with wastewater may achieve the required degree of disinfection by using less chlorine, and this will result in significant savings in chlorine dosing. This proposition was confirmed in this study by tests conducted in a full-scale investigation, where the chlorine dosage required to inactivate E. coli at the Burgersfort WWTW effluent was reduced by 50% from the mode of 6.43 mg/l before mixing to the mode of 3.0 mg/l after mixing. For effective chlorination, a disinfection system must be designed within wastewater treatment works for the wastewater to flow turbulently throughout a chlorine contact chamber and/or dosing point in order to achieve complete mixing within 1 minute of contact time. The mixing allows the maximum dispersal of the free chlorine in the wastewater and contact between chlorine and the microorganisms in the effluent. This ensures effective inactivation before the free chlorine reacts with other impurities present in wastewater that demand chlorine.

Abstract The book is intended as a handbook providing detailed instructions for the correct conducting of jar tests, which are needed for the optimisation of the coagulation/flocculation process. It contains the essential theoretical background of coagulation/flocculation, including a description of the influence of different parameters on the coagulation efficiency of various impurities (e.g. pH value and type/dose of coagulant), and floc properties and their separation (e.g. mixing intensity, mixing time, but also type/concentration of coagulant and impurities). The principle of jar tests is explained and parameters possible to optimize (i.e. coagulation pH, coagulant dose, flocculation aid dose, mixing intensity and mixing time) are discussed. Laboratory equipment for jar tests is proposed, including mixers and instructions for calculating a mixing intensity (necessarily expressed by the global shear rate/velocity gradient G). Mixing intensities for various purposes are recommended. Detailed practical instructions of how to perform jar tests follow, including a determination of the dose of reagents for pH adjustment and coagulant dose, dosing sequence, floc separation after jar tests by sedimentation and/or centrifugation simulating sand filtration, sampling, measuring necessary parameters (pH, coagulant residuals, alkalinity, residual impurity concentrations etc.), data recording, data processing and jar test evaluation (with specific examples). The handbook also contains a supplementary part with tables for conversion of the molar to mass concentration (and vice versa) of coagulants, and instructions for diluting coagulants and reagents for pH adjustment. ISBN: 9781789062687 (paperback) ISBN: 9781789062694 (eBook) ISBN: 9781789062700 (ePUB)

AbstractSustainable materials and additive manufacturing have the potential to increase material efficiency and minimize waste in the building process. One of the most promising materials is salt (sodium chloride). It is highly available as a residue of desalination and potash production processes and attracts attention due to its material properties (storage of humidity and heat). This research presents an investigation and evaluation of using salt as an alternative material in additive manufacturing. Thus, the focus of the study was on small-scale 3D printing with paste extrusion. Experimental studies of different salt mixtures with different binders, printing properties and other parameters were analyzed in three stages. In the first phase (P1) the mixing ratio of salt and potential binders (clay, gypsum, cement and starch) was defined; in the phase two (P2) the most promising mixture was selected, modified by additives and investigated by 3D image scan measurements; and in the last third phase (P3) the potential applications of salt in additive manufacturing were presented. As the research shows, the salt in material extrusion processes can substitute the main material by up to 70%, is successfully manipulated with different additives (to improve the workability of the printing mortar) and is highly dependent on the printer`s settings. For future full-scale 3D printing with salt many steps still have to be taken. However, incorporating salt in additive manufacturing showed a potential of saving material resources, addressing environmental issues and initiating new construction processes.

ABSTRACT Formation of the Central European tektites, known as moldavites, has been associated with a large meteorite impact in southern Germany 14.8 m.y. ago. The geochemical link between moldavites and their source materials, and the processes of their possible chemical differentiation still remain uncertain. Some differences in chemical composition between moldavites and sediments of corresponding age from the surroundings of the Ries crater could be explained by a hypothesis according to which biomass covering the pre-impact area contributed to the source materials. In a comparison of the geochemical compositions of a large representative set of moldavites and suitable Ries sediments, enrichment in elements K, Ca, Mg, and Mn and depletion of Na in moldavites, similar to redistribution of these elements during their transfer from soil to plants, could indicate the unconventional biogenic component in moldavite source materials. Simple mixing calculations of the most suitable Ries sediments and a model biogenic component represented by burned biomass residue are presented. The plausibility of the estimated biomass contribution considering reconstructions of the middle Miocene paleoenvironment in the pre-impact Ries area is discussed. No significant vapor fractionation is required to explain the observed variability of moldavite chemical composition.

A number of excellent descriptions of the techniques related to peptide chain assembly have already been published. These processes are also described in the operator manuals supplied by the peptide synthesis instrument manufacturers. Accordingly, the treatment of the subject presented here has been kept brief in order to provide more space in this volume for those topics not covered in detail in other publications of this type. The protocols have been written as they would be carried out using a manual peptide synthesis vessel. Whilst it is appreciated that most scientists preparing peptides will be using automated peptide synthesizers, it is not possible, given the wide variation in operating procedures, to describe how such methods may be applied to individual instruments. Particular emphasis has been given here to those operations which are typically carried out off-instrument, such as first residue attachment and peptide-resin cleavage. The operations described in this chapter can be carried out in a purpose-built peptide synthesis vessel or in a sintered glass funnel fitted with a three-way stopcock. The operation of the system is extremely simple: solvents are added from the top of the vessel, ensuring any resin adhering to the sides is rinsed down into the resin bed; the resin bed is agitated by setting the tap to position 1 to allow flow of nitrogen to the reaction vessel; solvents and reagents are removed by setting the tap to position 2 to connect the vessel to the vacuum. The use of such vessels has previously been described in detail. Peptide synthesis resins are extremely fragile and the beads, if wrongly handled, can easily fracture, leading to the generation of fines which can block reaction vessel filter-frits and solvent lines. It is particularly important that the correct method is used for mixing the resin and soluble reactants. Polystyrene-based supports are best agitated by bubbling an inert gas through the resin bed, or by shaking or vortexing the reaction vessel. Whilst all of these approaches are employed in commercial synthesizers, gas-bubbling and shaking are the most appropriate for use in manual synthesis.

A great deal of information is known about the solvent character of CO2 with a wide range of polymers and copolymers based on well-characterized and systematic solubility studies that are available in the literature (Kirby and McHugh, 1999). Nevertheless, the prediction of polymer solubility in CO2, or any solvent for that matter, presents a formidable challenge since contemporary equations of state are still not facile enough to describe the unique characteristics of a long-chain polymer in solution. The difficulty resides in accounting for the intra- and intersegmental interactions of the many segments of the polymer connected to a single backbone relative to the small number of segments in a solvent molecule. An additional challenge exists to describe the density dependence of the intermolecular potential functions used in the calculations since SCF–polymer solutions (SCF, supercritical fluid) can be highly compressible mixtures. In this brief review, the solvent character of CO2 is described using the principles of molecular thermodynamics and also using a select number of phase behavior studies to reveal the impact of polymer architecture on solubility. To form a stable polymer–SCF solvent solution at a given temperature and pressure, the Gibbs energy, shown in eq. 7.1, must be negative and at a minimum. . . . ΔGmix = ΔHmix − T ΔSmix (7:1) . . . where ΔHmix and ΔSmix are the change of enthalpy and entropy, respectively, on mixing (Prausnitz et al., 1986). Enthalpic interactions depend predominantly on solution density and on polymer segment–segment, solvent–solvent, and polymer segment–solvent interaction energies. The value of ΔSmix depends on both the combinatorial entropy of mixing and the noncombinatorial contribution associated with the volume change on mixing, a so-called equation-of-state effect (Patterson, 1982). The combinatorial entropy always promotes the mixing of a polymer with a solvent. However, the noncombinatorial contribution can have a negative impact on mixing as a result of monomer–monomer interactions that arise due to the connectivity of the segments in the backbone of the polymer chain.

This paper reports the geometrical optimization of an effervescent atomizer used in the combustion of used recycled oils. The objective was to obtain stable flames while minimizing the emission levels. A test facility was designed and constructed, which included: a furnace rated at a thermal input of 300 kW and a swirl generator as a part of the burner setup for the application of the effervescent atomizer. Other auxiliary facilities were also included, such as: cooling system, air supplies and pre-heating gas burner. Combustion tests were carried out with used recycled oil having a viscosity of 46 mm2/s (50°C) and a higher heating value of 44.6 MJ/kg. Results included qualitative observations of the ignition and flame stabilization, emission concentrations and LDA velocity measurements of the flow field produced by the swirl generator with and without flame. The results show a good performance of the swirl generator in the process of fuel/air mixing inside the furnace, which results in very low emission levels. The various tests carried out with different geometric configurations of the burning facility clearly suggest that the high velocity and penetration of the spray require an adequate design of the swirl generator and the nozzle orifice, in order to obtain a good air/fuel mixture inside the furnace.

Co-utilization of coal and lignocellulosic biomass has the potential to reduce greenhouse gases emission from energy production. As a fundamental step of typically thermochemical co-utilization (e.g., co-combustion, co-gasification), co-pyrolysis of coal and lignocellulosic biomass has remarkable effect on the conversation of the further step. Thermal behavior and kinetic analysis are prerequisite for predicting co-pyrolysis performance and modeling co-gasification and co-combustion processes. In this paper, co-pyrolysis behavior of a Chinese bituminous coal blended with lignocellulosic agricultural residue (wheat straw collected from north of China) and model compound (cellulose) were explored via thermogravimetric analyzer. Bituminous coal and lignocellulosic agricultural residue were heated from ambient temperature to 900 °C under different heating rates (10, 20, 40 °C·min−1) with various mass mixing ratios (coal/lignocellulosic agricultural residue ratios of 100, 75/25, 50/50, 25/75 and 0). Activation energy were calculate via iso-conversional method (eg. Kissinger-Akahira-Sunose, Flynn-Wall-Ozawa and Starink methods). The results indicated that pyrolysis rate of coal was accelerated by wheat straw under all mixing conditions. Cellulose promoted the pyrolysis rate of coal under equal or lesser than 50% mass ratio. Some signs about positive or passive synergistic effect were found in char yield. Char yields were lower than that calculated from individual samples for bituminous coal and wheat straw. With the increasing of cellulose mass ratio, the positive synergies on char yields were reduced, resulting in passive synergistic effect especially under higher coal/cellulose mass ratio (25/75). Nonlinearity performance was observed from the distribution of activation energy.

Abstract Droplet evaporation is a complex phase change process with a wide range of cooling applications, such as spray cooling and dropwise hotspot cooling in microelectronics, to name a few. The hybrid nanofluid droplet evaporation and its residue effects on evaporation of the subsequent hybrid nanofluid droplet is investigated in this research. Silver-graphene (Ag-GNP) hybrid nanofluid exhibiting synergistic thermal properties is investigated and prepared by dispersing silver nanoparticles along with graphene nanoplatelets in water at 0.1% volume fraction and with different mixing ratios, followed by ultrasonication. The evaporation rate and wetting characteristics of a 3 μl volume of Ag-GNP hybrid nanofluid droplet on a copper surface were studied using an optical tensiometer. Once dried, the nanoporous structure of the residue surface was examined using a scanning electron microscope, while the surface roughness was measured using an optical profiler. Experiments were continued to further investigate the evaporation rate and wetting effects of the subsequent Ag-GNP hybrid nanofluid droplet over the residue surface. The results showed improved wetting characteristics, with 88% reduction in initial static contact angle and 163–196% enhancement in evaporation rate of the subsequent Ag-GNP hybrid nanofluid droplets over the residue surfaces as compared to the copper surface.

Combustion emission is one of the most important issues in the design of industries. Todays’ strict environmental standards have limited the productions of CO, NOx, SOx, and other hazardous pollutants from the related industries. In this work, we study a typical oil refinery incinerator, which is used to burn waste gases residue produced during bitumen production process. The waste gas mainly includes a mixture including N2, H2O-vapor, and O2 species. Additionally, there are significant amounts of CO species and CxHy droplets in the waste gas composition. The measurements show that the CO emission becomes so crucial in high flow rate of feeding waste gas to the incinerator. Here, we numerically simulate the combustion process in this incinerator by solving the full turbulent reacting flow equations. In this regard, we use the finite-volume method to solve the RANS equations. For turbulence modeling purposes, we use the two-equation k-ε model along with standard wall functions. The non-premixed combustion is simulated by solving the mixture fraction equations for both fuel and waste gas streams. The interaction between turbulence and combustion is properly considered in the current modeling. We use the P1 method to solve the radiation transfer equation in emitting and absorbing medium of combustion gasses. The WSGG model is used to consider the absorption coefficient variation. The set of governing equations are solved using a SIMPLE-based algorithm. The current solutions provide good knowledge about the mixing pattern of flue gas and air-fuel streams in the incinerator. The improper mixing in the incinerator suggests we present a new design to re-design the waste gas inlet to the incinerator. Our simulation shows that the new design would result in substantial improvement in mixing process of these two streams. We find that this new design would effectively reduce the CO ppm at the exit of incinerator’s stack.

A novel combustion technique, based on the Double Cone Burner, has been developed and tested. NOx emissions down to very low levels are reached without the usual strong dilution of the fuel for MBtu syngases from oxygen blown gasification of coal or residual oil. A limited amount of dilution is necessary in order to prevent ignition during the mixing of fuel and combustion air. The relevant properties of the fuel are reviewed in relation to the goal of achieving premixed combustion. The basic considerations lead to a fuel injection strategy which is completely different from that for natural gas. A high speed premixing system is necessary due to the very short chemical reaction times of MBtu fuel. Fuel must be prevented from forming ignitable mixtures inside the burner for reliability reasons. A suitable fuel injection method, which can be easily added to the ABB double cone burner, is described. In common with the design of the standard EV burner, the MBtu EV burner with this fuel injection method is inherently safe against flashback. Three dimensional flow field and combustion modelling is used to investigate the mixing patterns and the location of the reaction front. Two burner test facilities, one operating at ambient and the other at full gas turbine pressure, have been used for the evaluation of different burner designs. The full pressure tests were carried out with the original gas turbine burner size and geometry. Combing the presented numerical predictive capabilities and the experimental test facilities, burner performance can be reliably assessed for a wide range of MBtu and LBtu fuels (residue oil gasification, waste gasification, coal gasification etc.). The atmospheric tests of the burner show NOx values below 2 ppm at an equivalence ratio equal to full load gas turbine operation. The NOx increase with pressure was found to be very high. Nevertheless, NOx levels of 25 vppmd (@ 15% O2) have been measured at full gas turbine pressure. Implemented into ABB’s recently introduced gas turbine GT13E2 the new combustion technique will allow a more straightforward IGCC plant configuration without air extraction from the gas turbine to be used.

Abstract Severe fixed Coke in the industrial residue fluid catalytic cracking (RFCC) riser reactor often results in the reduction of product yield and unplanned unit shutdown. It is difficult to simultaneously depict physical and chemical formation of fixed coke near wall due to no approach and coking model. In this paper, the complex gas-solid-liquid three phase flow, mixing and cracking reaction are in agreement with the industrial data by 3D reactive simulation with multiphase Eulerian granular model coupling with the vaporization empirical correlation and the energy-minimization multi-scale (EMMS) drag and mass transfer models. A new coking index is developed to predict the formation possibility of fixed coke based on the 3D accurate simulation. The variations of coking profiles at different diameter of oil droplet are investigated. The results indicate that the fixed coke formation can be well depicted by the coking index. The predicted of fixed coke in the feed injection zone is same with the actual positions in industrial unit, which mainly located near the walls of the 0.5∼3.0m height above the feed nozzles and the circumferential between adjacent nozzles. The feed oil droplet size can improve the formation possibility of fixed coke.

In this paper we report the results of pilot tests of flocculation/precipitation setup for dust-suppressor (DS) and transuranic elements (TUE) removal from wastewaters of Chernobyl Nuclear Power Plant (ChNPP), including those of the Object “Shelter”. Tests were performed on the pilot unit (PU), which included service tank, precipitation tank, and accumulation tank, 300 dm3 each, connected with pipelines with dosing and pumping equipment, and throttle valves providing controlled dosing, mixing, precipitation and mechanical filtration of radioactive wastewaters under different conditions. The reagent compositions used in pilot tests were based on coagulant POLYPACS-30 LF (aluminum polyoxychloride), synthetic cationic flocculants Besfloc K6634, K510CA, K6732 («Kolon Life Science, Inc», South Korea) varying in molecular weight and charge density, and natural cationic flocculant «Chitofloc» (Institute of Chemistry FEBRAS, Russia). The following wastewater parameters were controlled during the pilot tests: pH, dry residue, oxygen consumption, total α- and β-activity, isotope composition, optical density and DS content. The precipitation setup demonstrated lower efficiency DS removal from evaporator concentrates due to high ionic strength suppressing the electrostatic interactions between coagulants/flocculants and oppositely charged colloids of DS and TUE. The residual DS concentration was below 1 mg/L that corresponds to decontamination factor above 300 for the drainage water samples tested. The chitosan-based “Chitofloc” flocculant appeared to be the reagent which was the least sensitive to negative effect of ionic strength; however, the decontamination factor in DS removal was not higher than 5 due to suppressing of electrostatic interactions in high salinity media. Analysis of α-activity of water samples after flocculation/mechanical filtration revealed that TUE were not detected in the drainage water samples with DS content reduced to 2 mg/L that corresponds to TRU decontamination factor above 10000 and confirms immobilization of TUE in DS precipitate.

Recycling plastics is widely accepted as the most beneficial end use of plastic products. Consequently, many cities are turning towards single-stream recycling to make it easier for consumers to recycle and to increase the total amount of municipal solid waste (in particular, energy-dense plastic waste) that is diverted to recycling facilities. However, single-stream recycling Materials Recovery Facilities (MRFs) are now faced with sorting more diverse material flows with increased contamination from the mixing of recyclable and non-recyclable materials, leading to roughly 5–10% of the incoming material being sent to landfills. Converting the energy dense MRF waste material into solid recovery fuel (SRF) pellets creates an additional use for the products, diverts the material from the landfill, and displaces some fossil fuel use. However, there are some non-obvious energetic and environmental tradeoffs that require analysis to quantify. That is the intent of the research presented here. To analyze the potential of SRFs as viable alternative fuel sources, a first-order thermodynamic materials and energy balance was constructed using cement kilns as a test-bed. The proposed methodology allows for a range of traditional fuels to be compared with and without supplemental SRF. The SRF case can be benchmarked against the reference case, or conventional plastic end-of-life pathway, landfilling of the non-recycled plastic. The comparison includes transportation and processing steps required for each pathway, including any additional sorting needed for creating the SRF as well as the pelletization process itself. A robust methodology was created that allows for the MRF residue to be adjusted on a compositional basis because residue composition varies by season and location, which affects the analysis. Additionally, proximity to SRF conversion facilities and cement kilns will vary for each MRF and can impact the analysis so the methodology allows these factors to be adjusted. A test case was studied to compare the landfilling or combustion of MRF residue in a cement kiln at a rate of 0.9 metric tons per hour (7884 metric tons for a one year period). The analysis details the total energy consumed, landfill avoidance, amount of fuel displaced, and the total equivalent CO2 emissions of each scenario. The methodology successfully models the reference and SRF case and is robust enough to be used with a wide variety of potential SRF scenarios. A few parametric studies were performed on the transportation and landfill variables to determine their relative effect on results. It was found that additional transportation would have minimal effect of total energy consumption. When using SRF as a supplementary cement kiln fuel, the equivalent CO2 reductions are higher in scenarios with low methane capture efficiency at the landfill. Overall, it was found that using SRF as a supplementary fuel at cement kilns reduces the total fossil energy consumption and total equivalent CO2 reductions by 6% and 76%, respectively.

In this work carbon combustion efficiencies in circulating fluidized bed combustion (CFBC) when co-firing biomass and coal mixtures were studied. Experimental results were obtained from the combustion of two kind of coals with a forest residue (Pine bark) in a CBF pilot plant (0.3MWth) with 20-cm i.d. and 6.5-m height. The effect of operating conditions such as percentage of biomass in the feed, temperature, excess air, air velocity and percentage of secondary air on carbon combustion efficiency was studied. A mathematical model for the co-combustion of coal and biomass in a circulating fluidized bed boiler has been developed. The riser is divided in three zones with different hydrodynamic characteristics: bottom, splash and freeboard. The bottom bed has a constant voidage, determined by a modified two-phase theory. The solids are considered in perfect mixing and the gas in plug flow. The voidage in the splash region follows an exponential decay model. In the freeboard region, the solids and the gas are in plug flow, and a core-annulus structure is considered. Devolatilization of solid fuels is modeled with a particle reaction model which allows to determine the volatiles generation rate as a function of time and operating conditions. Kinetics of char combustion is modeled with the shrinking particle model with mixed control by chemical reaction and gas film diffusion, assuming that the ashes separate once formed. To consider that the char particles are a mixture of coal and biomass char particles, a weighted average combustion rate is defined taking into account the individual combustion rates. Population balances of char particles in the different regions were developed to calculate carbon concentrations. The developed model can predict the different gas concentrations along the riser, such as oxygen, SO2, CO, CH4, etc..., and the carbon combustion efficiency. The experimental results of carbon combustion efficiencies and gas emissions were compared with those predicted by the model and a good correlation was found for all the conditions used.

BZ25-1 oilfield is located in the southeast of Bohai bay which geographically lies between 119°00′ to 119°15′ east longitude and 38°10′ to 38°20′ north latitude. It has two oil blocks, including Shahejie (SHJ) waxy oil and Minghuazhen (MHZ) heavy oil, with six wellhead platforms WHPA∼WHPF and six submarine pipelines. Therein, the WHPC-WHPB and WHPB-SPM (Single Point Mooring) pipelines transport the mixture of the two produced crude oils. However, the mixing of the two oils will certainly bring out a change in their components and properties, which directly affects the safe operation of the submarine pipelines and offshore production facilities. Therefore, this paper compounds three kinds of MHZ/SHJ mixed oils with blending ratios of 1:1, 3:1 and 9:1, mainly studies how the components, rheological and thermophysical properties of the oil mixtures change with the blending ratio. The major objective of this study is to evaluate the compatibility of the two crude oils and provide a theoretical basis for the production optimization and risk elusion of the oilfield. The results of the study show that the components and properties of SHJ crude oil are quite different from those of MHZ oil, the flow behavior of SHJ oil is more sensitive to temperature. As MHZ oil in the compounds increases, the contents of asphaltene, resin, sulfur and carbon residue will increase except wax contents, their viscosities, densities and flash points will also increase, but their pour points, yield stresses, calorific values and other major thermophysical parameters will decrease. A blending ratio of 2∼7:1 for MHZ to SHJ crude oil can be concluded to make the properties of the compounds meet the safe and economic requirements of the subsea pipeline and offshore facility operations and ensure the compatibility of the mixed oils. In actuality, the field operations have confirmed that the recommended blending ratio is reasonable and practicable.

A comprehensive study of Mississippi Valley-type base-metal deposits across the Canadian Cordillera was done to compare and contrast their features. Extensive dissolution of host rocks is followed by multiple generations of dolomite cements from early, low-temperature, fine-grained to coarser, higher temperature types that overlap with Zn-Pb sulfide minerals; late-stage calcite occludes residual porosity. Dolomite is generally chemically stoichiometric, but ore-stage types are often rich in Fe (&amp;lt;1.3 weight per cent FeO) with small sphalerite inclusions. Sphalerite-hosted fluid inclusions record ranges for homogenization temperatures (77-214°C) and fluid salinity (1-28 weight per cent equiv. NaCl±CaCl2). These data suggest fluid mixing with no single fluid type related to all sulfide mineralization. In situ secondary ion mass spectrometry (SIMS) generated delta-18OVSMOW values for carbonate minerals (13-33 permille) reflect dolomite and calcite formation involving several fluids (seawater, basinal, meteoric) over a large temperature range at varying fluid-rock ratios. Sphalerite and pyrite SIMS delta-34SVCDT values vary (8-33 permille) but in single settings have small ranges (&amp;lt;2-3 permille) that suggest sulfur was reduced via thermochemical sulfate reduction from homogeneous sulfur reservoirs. Collectively, the data implicate several fluids in the mineralizing process and suggest mixing of a sulfur-poor, metal-bearing fluid with a metal-poor, sulfide-bearing fluid.

Cold-recycling treatments are gaining popularity in the United States because of their economic and environmental benefits. Curing is the most critical phase for these treatments. Curing is the process where emulsion breaks and water evaporates, leaving residual binder in the treated material. In this process, the cold-recycled mix gains strength. Sufficient strength is required before opening the cold-treated layer to traffic or placing an overlay. Otherwise, premature failure, related to insufficient strength and trapped moisture, would be expected. However, some challenges arise from the lack of relevant information and specifications to monitor treatment curing. This report presents the outcomes of a research project funded by the Illinois Department for Transportation to investigate the feasibility of using the nondestructive ground-penetrating radar (GPR) for density and moisture content estimation of cold-recycled treatments. Monitoring moisture content is an indicator of curing level; treated layers must meet a threshold of maximum allowable moisture content (2% in Illinois) to be considered sufficiently cured. The methodology followed in this report included GPR numerical simulations and GPR indoor and field tests for data sources. The data were used to correlate moisture content to dielectric properties calculated from GPR measurements. Two models were developed for moisture content estimation: the first is based on numerical simulations and the second is based on electromagnetic mixing theory and called the Al-Qadi-Cao-Abufares (ACA) model. The simulation model had an average error of 0.33% for moisture prediction for five different field projects. The ACA model had an average error of 2% for density prediction and an average root-mean-square error of less than 0.5% for moisture content prediction for both indoor and field tests. The ACA model is presented as part of a developed user-friendly tool that could be used in the future to continuously monitor curing of cold-recycled treatments.