Loss On Ignition Research Articles

Monitoring the Composting Process of Olive Oil Industry Waste: Benchtop FT-NIR vs. Miniaturized NIR Spectrometer

Miniaturized near-infrared (NIR) spectrometers are revolutionizing the agri-food industry thanks to their compact size and ultra-fast analysis capabilities. This work compares the analytical performance of a handheld NIR spectrometer and a benchtop FT-NIR for the determination of several parameters, namely, pH, electrical conductivity (EC25), C/N ratio, and organic matter as LOI (loss-on-ignition) in compost. Samples were collected at different stages of maturity from a full-scale facility that processes olive mill semi-solid residue together with olive tree pruning residue and animal manure. Using an FT-NIR spectrometer, satisfactory predictions (RPD > 2.0) were obtained with both partial least squares (PLS) and support vector machine (SVM) regression, SVM clearly being superior in the case of pH (RMSEP = 0.26; RPD = 3.8). The superior performance of the FT-NIR spectrometer in comparison with the handheld spectrometer was essentially due to the extended spectral range, especially for pH. In general, when analyzing intact samples with the miniaturized spectrometer, sample rotation decreased RMSEP values (~20%). Nevertheless, a fast and simple assessment of compost quality with reasonable prediction performance can also be achieved on intact samples by averaging static measurements acquired at different sample positions.

Paleoecological History of Maplecrest Fen, Catskill Mountains (NY, USA) From Deglaciation to the Industrial Age

ABSTRACTAimTo develop the palaeoecological and palaeoclimatic history of Maplecrest Fen, Greene County, NY.LocationCatskill Mountains, New York.Time Period13,500 calendar years to present (ybp, present = 1950).TaxonAngiosperms, gymnosperms and bryophytes.MethodsWe used pollen and spore analysis, macrofossil analysis, loss‐on‐ignition (LOI) and X‐ray fluorescence (XRF) analysis of a 7.8 m sediment core from the Fen along with AMS radiocarbon dates retrieved from the identified terrestrial macrofossils.ResultsLate‐glacial and Holocene vegetational change from ice withdrawal reveals the development of a shallow lake and then fen to the present. The boreal spruce (Picea), fir (Abies) and paper birch ((Betula papyrifera) pollen signature near the base of the core (Zone M2) suggest a Younger Dryas (YD) signal overtopping warmer Allerod aged basal sediments. The early Holocene white pine (Pinus strobus) is followed by increases in hemlock (Tsuga) and beech (Fagus), ushering in a moister climate. About 5200 ybp drought is indicated by the well‐known hemlock biostratigraphic decline in the Northeast. Drepanocladus moss and stonewort (Chara) shift to sedges (Carex) and violets (Viola) locally present. For the next 5000 years, the vegetation will remain relatively stable with lower temperatures suggested by the return of spruce and fir. Ragweed (Ambrosia) rise along with other weedy taxa marks European settlement near the top 50 cm of the core, along with a striking increase in anthropogenic lead, as seen using X‐ray fluorescence.Main ConclusionsDeglaciation began in the Catskills at a high elevation about 13,500 years ago and recession of ice from the Laurentide margin proceeded at about 0.1 km/year. Temperature shifts promoted changes in the boreal forest including warming and cooling, and drought and wetter intervals both appear in the Holocene history but do not appear to be easily forecast as climate continues to warm.

Investigation on a novel mixed collector for carbon recovery from coal gasification fine slag: Experimental insight and macro molecular simulations

The effectiveness of flotation for decarbonizing fine slag from coal gasification depends on the selection of appropriate collectors or surfactants. This study explored the synergistic effect of kerosene combined with cationic surfactants, including dodecyl trimethylammonium chloride, dodecylamine, and dodecylamine hydrochloride, on recovering residual carbonaceous material from coal gasification fine slag, using both MD and experimental simulations. The Scanning electron microscopy and X-ray spectroscopy revealed that the water molecules and oxygen-rich silicon glass beads dominated the slag surface, while the XPS analysis demonstrated that the functional groups containing oxygen on the residual carbon surface promote hydrogen bonding with water molecules in the flotation solution. The results suggested that the highest yield, along with optimal Loss on Ignition (LOI) and combustible recovery, was achieved at the 10−5 mol/L surfactant concentration. The MD simulations demonstrated that dodecylamine had the highest diffusion coefficient and adsorption capacity, explaining its superior interaction with residual carbon surfaces and its effectiveness in the decarbonization process. This approach contributed to the valorization and reuse of carbon generated by the waste of coal gasification fine slag.

Extreme hydroclimatic events and response of vegetation in the eastern QTP since 10 ka

Abstract Climate variations during the Holocene significantly impacted vegetation dynamics in the eastern Qinghai-Tibet Plateau (QTP). However, vegetation evolution in response to regional climatic trends and events during this interval remains controversial. Here, we present well-dated decadal-resolution loss on ignition (LOI) and grain size records from the Xing Co Lake on the eastern QTP. The records show an overall drying trend since 10 thousand years ago (ka), with multiple extreme precipitation events observed during 10 to 7 ka. An extreme drought event occurred at around 5.5 ka, after which the climate was drier and unstable with several drought events. In comparison with the hydroclimate, insolation, and El Niño Southern Oscillation records, our data show a close correspondence with the summer insolation differential between 30°N and 30°S and El Niño events on orbital-millennium timescales. This suggested that the increased rainfall during the early Holocene on the eastern QTP can be attributed to the high insolation differential between 30°N and 30°S and low El Niño events. Conversely, the drying trend in the late Holocene appears to correlate with a low insolation differential and high El Niño events. Whenever ice-rafted debris events occurred in the North Atlantic, there was a corresponding occurrence of drying events in the late Holocene in the Zoige Basin. This suggested that teleconnection between the precipitation on the eastern QTP and the North Atlantic climate exists in the Holocene. When compared to independent hydroclimatic and arboreal pollen (AP%) records on the eastern QTP, the evolutionary trends and events of AP% align closely with local hydroclimate changes. This suggested that arboreal coverage could rapidly respond to climate change during the Holocene, but further studies are needed.

Comparison of environmental impacts from pyrolysis, gasification, and combustion of oily sludge

Thermochemical treatment of oily sludge (OS) has been demonstrated to be an effective approach for resource and energy recovery. However, the migration and emission of potential pollutants have limited its further development. In this study, the environmental impacts, including aromatic compounds in liquid products, N-, S-, and Cl-containing pollutants in gaseous products, and residual organic matter and heavy metals in solid residues, during the pyrolysis, gasification, and combustion processes of OS are comparatively investigated. The results indicate that the aromatics in the liquid products obtained from pyrolysis and gasification are primarily hydrocarbons with 10, 14, and 16 carbon atoms, and the corresponding degree of unsaturation is between 7 and 16. By contrast, the aromatics produced during combustion are mainly hydrocarbons with 10–12 carbon atoms and an unsaturation degree of 7. The liquid products from gasification of OS contain aromatics with more carbon atoms and a higher degree of unsaturation, suggesting potential issues of recalcitrant aromatics and tar by-products during the gasification process. The release behaviors of N-, S-, and Cl-containing pollutants during the thermochemical treatment of OS are closely related to the specific thermochemical technology and treatment temperature. At 550 °C, these pollutants are gradually released from the OS. By contrast, at 950 °C, they are released over a narrow temperature range with significantly higher concentrations. Furthermore, compared with the peak concentrations of SO2 and HCl during thermochemical processing at 550 °C, these values increase by 1–2 orders of magnitude at 950 °C. With the increase in treatment temperature, the loss on ignition (LOI) of residues from pyrolysis or gasification of OS gradually decreases and stabilizes around 0.5 %. On the other hand, the LOI from combustion fluctuates around 1.0 %. In addition, the removal rates of total organic carbon in the residues from all three thermochemical processes exceed 98.89 %. However, the potential ecological risks associated with heavy metals in the residues from thermochemical treatment of OS also increase to some extent. Cr, Cu, and Zn are found to evaporate and escape into liquid and gaseous products, while Pb is retained in the residues. Notably, the residue from combustion poses the highest environmental risks among the three processes.

Multi-proxy reconstruction of climate changes from the Medieval Climate Anomaly to the Little Ice Age in Southeast China

Exploring climate fluctuations across geological eras provides crucial historical context for addressing contemporary global climate challenges. This research leverages multi-proxies records analytical techniques, including pollen and charcoal analysis, X-ray fluorescence (XRF), and assessments of humification degree and loss on ignition (LOI), alongside paleoclimate simulations based on an alpine peat bog in Jiangxi Province, Southeast China. The study aims to provide a comprehensive review of vegetation evolution, climatic shifts, East Asian summer monsoon (EASM) intensity, and the potential drivers behind EASM behavior over the past two millennia. Our findings reveal a significant transition in precipitation and temperature patterns from the Medieval Climate Anomaly (MCA, 960–1420 CE) to the Little Ice Age (LIA, 1420–1850 CE). A distinct pattern emerges, highlighting particularly wet periods occurring between 960–1050 CE, 1190–1250 CE, and 1350–1400 CE, as well as significant droughts during 1430–1550 CE, 1590–1650 CE, 1680–1720 CE, and 1750–1800 CE. When compared to our temperature reconstruction series and precipitation data, a clear correlation emerges—wet phases align with warmer period characteristic of the MCA. Based on our simulation results, we suggest that ENSO oscillations and the Indo-Pacific warm pool played a substantial role in driving climate dynamics from the MCA to the LIA.

Methods for Measuring Organic Carbon Content in Carbonate Soils (Review)

In world practice, the measurement of the mass fraction of carbon of organic compounds (Corg) in soils containing carbonates is carried out in various ways. An analysis of methods that allow solving this problem was carried out, including the latest approaches: thermogravimetry, differential scanning calorimetry, spectroscopy. It has been shown that the presence of CaCO3 does not prevent the use of the dichromatometric method (Tyurin, Walkley-Black) for determining Corg. The disadvantages of the method boil down to the laboriousness of the analysis, the need for constant presence of the operator, incomplete oxidation of organic compounds and environmental pollution. The method of measuring soil mass loss-on-ignition (LOI) is economical and rapid, but it gives an overestimated Corg content, which is associated with the inadequacy of the conversion factor of 1.724, the presence of adsorbed and chemically bound water, as well as mineral components decomposing at T = 105–550°С. The most relevant solution for finding Corg in carbonate soils is to use an analyzer and a calcimeter, although the accuracy of Corg measurements in the presence of carbonates is significantly reduced due to the quadratic summation of the errors of the two methods. The high cost of the device, maintenance, verification and repair limit its widespread use in soil laboratories. To measure the content of soil carbonates, it is possible to use both gravimetric (LOI) and volumetric (calcimeter) methods. The use of the latter is preferable for soils with a predominance of CaCO3 in carbonate composition. Preliminary removal of carbonates from soil samples is labor-intensive and can lead to partial loss of Corg due to acid extraction. The high cost of instruments and the lack of libraries of soil spectra hinder the development of vis-NIR and MIR spectroscopy as an alternative to “wet” chemistry methods. Continuing comparative studies will improve the understanding of the spatial patterns of distribution of carbon in soil organic compounds.

Organic matter and nutrient content within putting green root zones in Tennessee

AbstractOrganic matter and soil nutrient accumulation within putting green root zones affects surface quality and performance. Research was conducted to explore differences in organic matter and nutrient content within creeping bentgrass (CBG; Agrostis stolonifera L.) and ultradwarf bermudagrass [UDBG; C. dactylon (L.) Pers. × C. transvaalensis Burtt‐Davy] putting greens. Sampling was conducted from January 30 to February 23, 2023, on 22 putting greens (11 CBG and 11 UDBG) in Tennessee. Forty cores (1.91‐cm diameter by 10‐cm depth) were randomly collected from each putting green and analyzed for total organic material (TOM; undisturbed cores) by profile depth (0–2 cm, 2–4 cm, and 4–6 cm), TOM throughout a 10‐cm core, soil organic matter (SOM; passed through sieve with 2 mm openings) throughout a 10‐cm core, and nutrient content. All organic matter measurements were determined via loss‐on‐ignition (LOI) testing, whereas nutrient content was determined by Mehlich‐3 extraction. LOI testing at 440°C resulted in greater TOM values than 360°C; however, values from both temperatures were closely related (R2 = 0.99). TOM values from UDBG greens were greater than those recorded on CBG at all profile depths. Greens established via no‐till conversion contained more TOM than those planted in a constructed sand‐matrix root zone. While TOM and SOM were associated (R2 = 0.62), removing verdure for SOM assessments reduced the amount of organic material in each sample by 38% and increased variability. Nutrient contents were lower than sufficiency level of available nutrients benchmarks but exceeded minimum levels for sustainable nutrition.

Permeability and self-healing behavior of alkali activated geopolymers for well cementing applications

Geopolymers, also identified as alkali-activated materials (AAM), are alternative well-cementing materials with a lower carbon footprint than traditional ordinary Portland cement (OPC). Geopolymers are formed by combining an aluminosilicate precursor, such as fly ash (FA), with an alkaline activator solution. Among their merits is an ability to self-heal after becoming damaged, which can be exploited to restore permeability, sealing ability, zonal isolation, and well integrity in wells that suffer from cracking, fracturing, or debonding in their annular cement sheaths and abandonment plugs.This study investigates the self-healing ability of various alkali-activated Class F fly ash-based geopolymers. Liquid sodium hydroxide (LSH), liquid sodium silicate (LSS), and solid sodium silicate (SSS) were used as activators for the preparation of geopolymer specimens, while Class H OPC was used as the control material. Permeability was characterized using pressure transmission tests (PTT). The tested samples were of different compositions, curing ages (7-day and 28-day), damage stages (pristine, damaged after freeze-thaw cycling, self-healed after post-damage curing), and damage severity (low, medium, and high). Fourier-transform infrared-spectroscopy (FTIR) and loss on ignition (LOI) tests were performed to examine the geopolymer reaction over time, in an attempt to relate the various permeability results to the geopolymerization process. The experimental results show that geopolymers possess low permeability, comparable to – or lower than – OPC, and that effective permeability restoration occurs in geopolymers, even after high degrees of damage. The implication of this work is that geopolymers are promising alternative barrier materials to OPC with a superior ability to guarantee low barrier permeability and appropriate zonal isolation, keys to wellbore integrity over the entire lifecycle of wells, even if those wells suffer from damage.

Carbon removal flotation performance and economic analysis of different coal fly ash using waste fried oil as a collector

Collector consumption in flotation is significant, and petrochemicals like kerosene, being non-renewable and expensive, are commonly used collectors; therefore, finding suitable alternatives to reduce costs is essential. Waste fried oil (WFO) possesses properties similar to those of kerosene, making it a viable substitute for flotation processes. In this study, the flotation performance was analyzed and economic analysis of WFO as a collector was performed for circulating fluidized bed furnace fly ash (CFBFA) and pulverized coal furnace fly ash (PCFFA). The interaction mechanism between WFO and fly ash was analyzed using contact angle, Fourier-transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS) tests. The findings revealed that the optimal WFO dosage for coal fly ash closely correlates with the combustion technology used to obtain it. The study also established well-fitted curves for the loss on ignition (LOI) of CFBFA and PCFFA with changes in WFO dosage. FTIR and XPS analyses revealed that the interaction of WFO carbon chains with nonpolar regions on the surface of unburned carbon in coal fly ash resulted in an increase in hydrophobic carbon chain groups on the surface of unburned carbon, and the combination of oxygen-containing groups in WFO with the hydrophilic sites on the surface of unburned carbon were the main reasons for the enhancement of hydrophobicity of unburned carbon particles. Moreover, the economic analysis revealed that flotation of 1 t of CFBFA and PCFFA with WFO can yield profits of 1.91 USD and 1.11 USD more, respectively, compared with kerosene, which has practical applications in industry.

Geology, mineralogy, geochemistry and genesis of volcano-sedimentary hosted Lake Abiyata diatomite in central main Ethiopian Rift

The Abiyata Diatomite deposit is located in the Main Ethiopian Rift, which is characterized by strong extensional tectonics. The deposit is mostly made up of diatomaceous earth, which is a sedimentary rock made up of the fossilized remnants of diatoms, which are tiny algae. Diatomite's geological, geochemical, and mineralogical features, as well as its formation, are discussed in this research. To characterize diatomite from Abiyata, chemical, mineralogical, technological, and micro paleontological examinations were conducted on samples collected from outcrops and stream sections. The XRD characteristic peaks of diatomite demonstrate that it is primarily made up of Opal A silica, however certain crystalline phases were discovered in adequate amounts. Quartz and feldspar were the predominant crystalline phases, with lesser amounts of Calcite, Cristobalite, Illite, Mordinite, Wairakite, Halloysite, Clinoaptilolite, Adularia, and Tridymite. From SEM photomicrographs diatomites are primarily formed of benthic freshwater diatom species such as Staurosirella pinnata, Staurosira construens, Pseudostaurosira brevistriata, Epithemia Sorex and surirella pinnata. Diatom species, sedimentary profile sections and mineralogical data suggest that diatomite was deposited in lacustrine-type freshwater shallow lake environment. Chemical data obtained from 10 diatomite samples show that while silica is the bodybuilding material for diatomite. i.e., Silica (SiO2), 76.9 %; Alumina (Al2O3), 3.49 %; Sodium Oxide (Na2O), 1.52 %; Potassium Oxide (K2O), 1.107 %; Iron Oxide (Fe2O3), 1.1 %; Loss on ignition (LOI) 13.7 and other oxides are below 1 %. Studies from technological properties like physical tests, chemistry, and mineralogy and micropaleontology of Abiyata diatomite suggest that calcined diatomite can be used for waste treatment processes in the filter aid industry and as filler material.

Soil carbon storage under different types of arid land use in Algeria

This study aims to assess the amount of organic carbon stored in soils, as it is an intention of knowing the sustainable soil management, by using two common methods for determining soil organic matter (SOM), namely oxidation with acidified wet dichromate (Walkley–Black method-WB) and loss on ignition (LOI). The study was carried with soil samples collected from a depth of 0 to 30 cm in the Saharan arid region of Ghardaïa (Algeria), with different land uses: agricultural, forest and pastoral. The results obtained from the LOI and WB methods were subjected to statistical analysis, and the relations between both methods were tested to investigate their relationship. The mean percentage of SOM values were 1.86, 2.42, 1.54 by using LOI, but, lower values of 0.34, 0.33, 0.36 were determined by using WB method, for agricultural, forest and pastoral soils respectively. A weak linear relationship between the two analytical procedures was obtained (R2 of 0.19 and 0.13 for agricultural and forest soils), while a medium relationship (R2 = 0.65) was found for pastoral soils when using linear adjustment. However, the opposite behaviour was found when we use the logarithmic adjustment. The study outcomes indicated discrepancies in the measurements of SOM values between the two methods, been higher those estimated with LOI. Finally, in order to identify the best methodology to measure soil organic matter in arid soils, more research is required in these extreme arid regions as they are a gap in world soil organic matter maps.

A survey study on arsenic speciation in coal fly ash and insights into the role of coal combustion conditions

Coal fly ashes (CFAs) are the low-density byproducts of the coal combustion process. Improper or uncontrolled CFA disposal poses significant environmental and health concerns due to the potential leaching of toxic heavy metals such as arsenic (As). Previous studies have investigated the content and speciation of As in different CFA samples, yet systematic information on As speciation in CFA with representative coal source and combustion conditions is still missing. Based on a recent survey study on the typical coal sources and combustion conditions across the U.S., this study selected 19 representative CFA samples to systematically investigate As speciation and potential correlations with these parameters. The composition, morphology, mineralogy, and As speciation of these CFA samples were characterized by complementary analytical, microscopic, and spectroscopic techniques. Synchrotron X-ray spectroscopy and microscopy analyses revealed the dominant As oxidation state to be As(V) and with strong associations to Ca, with the exception of 3 samples that had 19–51% As(III), likely due to the use of selective catalytic reduction (SCR) process. Principal component analysis was conducted to identify potential correlations of As concentration and oxidation state with parameters such as major element content, loss on ignition (LOI), average particle size, coal source, and combustion condition. Al2O3 and FeO content were found to capture a majority of the variability. Results from this study provide fundamental basis for understanding the correlations between coal source, combustion conditions, CFA characteristics, and As speciation, and providing insights for downstream beneficial utilization or disposal management.

Chemical characterization of green liquor dregs from 16 Swedish pulp and paper mills between 2017 and 2019

Green liquor dregs (GLD) is an alkaline by-product from the pulp and paper industry with a pH between 10 and 14. Today most of the produced GLD in Sweden is landfilled. As a fine-grained alkaline material, it might be possible to use it for acid-generating mining waste remediation. To increase the utilization, quality characteristics and environmental performance need to be determined. In this study samples were collected 5 times from 16 mills during a period of 2.5 years, and were characterized by analyzing dry matter content, loss on ignition (LOI) 550 °C and LOI 950 °C, elemental analysis, pH, electrical conductivity, and calorific value. The results were then evaluated using multivariate statistics (PCA) as well as being compared to other studies and Swedish till. The results show that even if GLD is heterogenous (both within a mill and between different mills) trends can be seen for samples from most mills. When samples do stand out, it is predominately related to the same four mills. Most of the studied parameters showed characteristics favorable for use as a remediant; however, TOC, sulfur, and some of the elements require further study. In general, this study concludes that GLD can be a viable option for the remediation of small orphaned sulfidic mining sites and thus worthy of further studies on the interaction between GLD and acidic mining waste.Overall, GLD can be a good alternative for cost-effective remediation of smaller orphaned mining sites. It is readily available in large quantities, has the qualities needed for remediation of many orphaned acidic mining sites, and can often be locally sourced near the mining site. The use of GLD for mining site remediation is likely also a more sustainable method compared to traditional remediation methods.

Evaluation of low-cost carbon/metal electrodes as cathodes and anodes in sediment microbial fuel cells

In the present study, influence of different anode and cathode materials including carbon felt, carbon cloth, and several metal electrodes with or without carbon cloth covering on sediment microbial fuel cell (SMFC) performance was investigated. Results suggested that stainless steel poorly performed as cathode electrode whereas it exhibited reasonable performance as anode. In SMFCs with carbon felt cathode, anodes including 400 series stainless steel mesh and 300 series stainless steel plate, both covered with carbon cloth, led to higher maximum power densities of 88 and 87 mW/m−2, respectively, compared with carbon felt, carbon cloth, 400 series stainless steel mesh, 300 series stainless steel mesh covered with carbon cloth, and copper plate covered with carbon cloth (power densities of 40, 74, 53, 68, and 47 mW/m−2, respectively). They also resulted in higher loss on ignition (LOI) removals of 9.4 % and 8.7 %, respectively. Cyclic voltammetry results showed that stainless steel plate covered with carbon cloth produced the highest redox current that was two times that of the carbon cloth. In addition, electrochemical impedance spectroscopy indicated lower charge transfer resistance in the SMFC with anodes including 400 series stainless steel mesh (20.6 Ω) and 300 series stainless steel plate (25.7 Ω), both covered with carbon cloth, compared to other anode materials. These findings suggest that stainless steel electrodes covered with carbon cloth provide SMFCs with improved electrochemical characteristics that enhance their electricity production and organic matter removal.

Integrating selective flocculation techniques for enhanced efficiency in manufacturing processes: A novel approach through artificial neural network modeling

The use of medium and low-grade iron ore is gradually becoming more important due to the depletion of high-grade iron ore reserves and stringent environmental acts/rules. Slimes from iron ore washing were discarded in tailing dams; however, there is currently consideration for recovering iron values from ultra-fines as well. There are enormous fine dumps that are still unutilised. Hence, this study attempt to delve the optimization of iron ore slimes an indeed requirement for manufacturing and design in industries. Leveraging a flocculation process, coupled with the implementation of an Artificial Neural Network (ANN) predictive model, the Kiriburu processing plant serves as the primary source for iron ore slime samples. Chemical analyses of the collected iron samples reveal a composition featuring 58.24 % iron content, 3.47 % Al2O3, 4.72 % SiO2, and 5.18 % LOI (Loss on Ignition). The investigation explores the performance of the flocculation technique under varying pH levels, different pulp densities, and diverse flocculant dosages. Furthermore, the varying parameters selected are pH from 6 to 11, pulp density from 1 % to 15 %, and flocculant dose from 0.03 to 0.27 mg/g. The study's findings showcase a substantial improvement in the Fe grade of iron ore, escalating from 58.24 % to 66.12 %, with an impressive recovery rate of 82.54 % achieved using a flocculant dosage of 0.09 mg/g at pH 10. Additionally, a performance assessment of the selective flocculation method for iron ore slimes is conducted using an ANN predictive model, with recovery as the pivotal parameter. The input parameters for this model encompass pH, pulp density, and flocculant dosages. Employing a three-layer ANN model with a 3–3–1 architecture and utilizing feed-forward back propagation, the study demonstrates a close alignment between predicted values and experimental data, confirming the model's effectiveness for practical manufacturing applications. Information regarding the potential applications of the model's iron ore slime beneficiation efficacy for the manufacturing sector should be considered. This could entail lower waste, more effectiveness, or cost savings. Emphasise any possible ramifications for sustainability or the environment that would make the study pertinent in a larger perspective.

Advancing circular economy: A study of drinking water sludge for potential uses

The high demand for drinking water has increased the by-products from treatment plants, notably during coagulation-flocculation, leading to substantial sludges' accumulation. This study aims to focus on the characterization of drinking water treatment sludge (DWTS) batches from the three last years and statically studying it's uniformity, as exploring potential repurposing options. The samples were characterized using X-Ray Fluorescence (XRF), X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TGA), Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES), Loss On Ignition (LOI), and Granulometric analysis. The results evinced that DWTS have a sandy nature, the organic fraction takes third of the DWTS’ chemical composition, the amount of Al2O3 + SiO2 + Fe2O3 is slightly different, with 55.84, 57.47, and 56.14 % for DWTS21, DWTS22, and DWTS23 respectively, as per ANOVA results, which exhibited the consistency sludge composition among the samples, providing valuable insights into repurposing DWTS, and contributing to sustainable and eco-friendly practices in the construction industry especially DWTS21, which presents higher content of CaO with 2.95 %.

Clay influence on lightweight brick’s properties: Investigating the impact of waste’s nature and amount as secondary variables

The present study aims to examine whether incorporating a specific proportion of a particular waste material consistently yields bricks with favorable properties, regardless of the raw clay type utilized. In this context, different mixtures were produced with a clay named AMD2 and 0 wt%, 5 wt% and 10 wt% addition of two wastes named argan nut shell and wheat straw. A first investigation of the used raw clay material revealed the presence of Quartz as a dominant mineral, along with Orthoclase, Illite, and Hematite. Furthermore, the elaborated bricks have been subjected to a physical, mechanical, and structural characterization including loss on ignition (LOI), linear shrinkage (LS), water absorption (WA), apparent porosity (AP), bulk density (BD), and compressive strength (CS). A comparison between the current study and a previous one using the same waste materials and identical proportions of addition but employing a different clay type revealed notable differences in outcomes. In the previous study, bricks fabricated with AMD1 clay and 5 wt% of argan nut shell displayed excellent characteristics. However, in the current investigation using AMD2 clay, bricks with the same waste addition ratio exhibited less favorable properties. Specifically, bricks made with AMD2 clay and 5 wt% argan nut shell showed a loss on ignition of 7.30 %, a linear shrinkage of 3.7 %, a water absorption of 23.3 %, an apparent porosity of 38.20 %, a bulk density of 1.64 g/cm3, and a compressive strength of 9.90 MPa. These outcomes indicated a water absorption above the specified limit and significantly higher apparent porosity compared to bricks produced with AMD1 and 5 wt% argan nut shell, which met standard specifications. This variation highlights how the mineral composition of clay significantly impacts brick properties, even when using the same waste materials and proportions, confirming the importance of considering the raw clay material's nature in bricks’ production, and thus emphasizing the need for a preliminary study before combining clay and wastes in order to achieve excellent results.

On-Site Determination of Soil Organic Carbon Content: A Photocatalytic Approach

This investigation presents a new approach for evaluating soil organic carbon (SOC) content in farming soils using a photocatalytic chemical oxygen demand (PeCOD) analyzer combined with geographic information system (GIS) technology for spatial analysis. Soil samples were collected at various sites throughout Canada and were analyzed using sieve analysis, followed by further SOC evaluation using three distinct techniques: loss on ignition (LOI), Walkley-Black, and PeCOD. The PeCOD system, which relies on the photochemical oxidation of organic carbon, showed an exciting correlation between its evaluations and SOC content, making it a prompt and reliable method to evaluate SOC. In this investigation, finer materials such as clayey soils (soil fractions of (<50 µm)) demonstrated high SOC content compared to coarser ones (soil fractions of (>75 µm)) and decreased SOC content with increased soil depth, generally below the 30 cm mark. It should be noted that this investigation revealed that other variables, such as land management practices, precipitation, and atmospheric temperature, have drastic effects on the formation and residence time of SOC. GIS georeferencing еnablеd mapping of the SOC distribution and identification of hotspot areas with high SOC content. The results of this study have implications for sustainable farming, climate change mitigation, and soil health operations by providing farmers with schemes that amplify carbon sequestration while simultaneously improving soil health.

Influence of Different Proportions of the Addition of Electrocoagulated Metal Sludge (EMS) Obtained from Oily Wastewater Treatment on the Properties of Laboratory Bricks

Electrochemical wastewater treatment technologies are increasingly being used in practice, and the combination of electrocoagulation with advanced oxidation processes has been shown to increase treatment efficiency. The treatment of oily wastewater produces electrocoagulated metal sludge (EMS). In this work, the possibility of using different ratios of EMS produced during oily wastewater treatment was investigated. EMS was dried conventionally in an oven at 105 °C and used as a partial substitute for clay in the manufacture of laboratory bricks. The main research objectives of this study were to examine the possibility and justification of introducing EMS in brick production. The results show that an increase in the proportion of EMS in the manufacturing of bricks leads to a deterioration in the quality of the bricks. Bricks with an addition of 1 wt% and 5 wt% EMS showed the best properties. The loss on ignition (LOI), compressive strength, boiling water absorption and initial water absorption were determined at 5.7%; 49 N/mm2, 16%, 14 g/min/200 cm2, 15% for modified bricks with 1 wt% EMS and 6.3%, 48 N/mm2, 20%, 15 g/min/200 cm2 for modified brick with 5 wt%.