Waste Lime Research Articles

Potential Recovery of Biogas from Lime Waste after Juice Extraction Using Solid–Liquid Extraction Process

A large percentage of fruit mass is left as waste after the consumption or processing of citrus fruits. The inappropriate disposal of these wastes directly leads to environmental and economic concerns. However, scientific investigations have demonstrated that citrus wastes, due to their high concentration in soluble sugars, can be a source of cellulosic biomass for biogas recovery. d-Limonene, the major constituent of essential oils present in citrus wastes, is however, known to hamper the conversion process of citrus wastes to biogas. With the aim of improving biogas production, a study on the pre-treatment of lime fruit waste to reduce the effect of d-limonene was carried out. The pre-treatment process was done using hexane as the solvent in a solid–liquid extraction process to leach out essential oils from lime wastes. Solid–liquid extraction was carried out in a Soxhlet apparatus with pulverized lime waste at 68 °C for 180 min; then the residue was washed and aerated. From the pre-treatment procedure, 21.3 mL of essential oil was recovered, indicating an oil yield of 3.8%. Substrates of untreated and pre-treated lime waste were digested in batches under mesophilic conditions for a period of 28 days. The biogas yield of each substrate was evaluated and the results compared. Substrate of untreated lime waste yielded 66.9 mL/g VS. biogas after the digestion period. In comparison, pre-treated lime waste gave a better biogas yield of 93.2 mL/g VS. after 28 days, indicating an improvement in biogas yield by about 40%. The findings of this research show that there is a viable recovery option of biogas from lime waste, and recommendations of this research can be further explored to develop an economically viable biogas plant process that efficiently utilizes citrus wastes. This would boost the drive of government towards alternative sources of energy and also fulfil two of the sustainable development goals presented by the United Nations.

Sequential In-Situ Carbonation Process for the Preparation of Hand Sheets with Waste Lime Mud

In the pulp and paper industry, the white liquor obtained from the causticizing green liquor in the smelting process mostly contains NaOH and Na2S. These chemicals are returned to the digester for reuse in the pulping process. The lime mud (LM) material is obtained from the reaction of the causticization process in paper industries. It is mainly composed of CaCO3; it appears with a green color with a high moisture content; and it has a small proportion of impurities such as non-process elements, for example Fe, Na, Mg, Al, Si, P, and S oxides and other toxic metals. This lime mud has poor whiteness with less efficiency due to its contaminated with impurities. The recycling or reutilizing process for lime mud and solid wastes are minimizing its toxic effect on the environment. The present study proposed to improve the whiteness of the waste lime mud by the calcination and hydration process at high temperatures and reutilizing it for hand sheets, making the process improve the paper brightness. In this study, we used a lime mud sample for calcination at 1000 °C and 1200 °C for 2 h and hydration at different times (3–24 h) with different temperatures (30–80 °C) and measured the powder whiteness and hand sheet brightness. The results indicated that after the calcination and hydration process, the lime mud sample whiteness was improved and that re-utilization with pulp for making hand sheets also can improve the paper brightness. It can be concluded that waste lime mud sample purification and the re-utilization process are more advantageous in paper industries.

Chemical stabilization of expansive soil using liming leather waste ash

ABSTRACT The expansive soils have presented various challenges for geotechnical and civil engineers due to their low bearing capacity and high swelling-shrinkage characteristics. This study examines liming leather waste as an expansive soil stabilizer in ash form which has very limited use elsewhere. The black cotton soil-ash mix was checked for consistency limits, compaction parameters, UCS, CBR, swell and swell pressure for different proportions of liming waste ash. It was observed that the plasticity index, swell and swell pressure of the soil show a substantial decrease upon addition of the waste ash whereas the UCS and CBR values show a marked increase with unsoaked and soaked CBR escalating by around 138% and 310% respectively. The addition of 6% to 8% liming waste ash produced most desirable soil properties. The test results are supported through XRD, SEM and EDX analysis which confirm the formation of cementitious silica gel in various forms.

Utilization of fly ash and waste lime from pulp and paper mills in the Argon Oxygen Decarburization process

Fly ash and waste lime are solid wastes generated in pulp and paper mills. Due to high CaO contents, these secondary lime materials can be potentially utilized in the steelmaking process to partially replace primary lime. In this study, fly ash and waste lime from Swedish pulp and paper mills were made into briquettes and for the first time utilized as slag formers to replace primary lime in a pilot-scale Argon Oxygen Decarburization (AOD) stainless steelmaking process. The purpose was to evaluate how these CaO-containing materials could affect the AOD process and the steel quality. The results show that the S, P and CaO contents in the fly ash and waste lime are important concerns for metallurgical application. Firstly, due to lower CaO contents (61.5% CaO in fly ash and 90.6% CaO in waste lime versus 95.2% CaO in primary lime), utilization of these secondary lime materials could lead to higher slag amounts in the AOD converter. Secondly, due to higher S and P contents (0.40% S and 0.26% P2O5 in fly ash, 0.11% S and 0.75% P2O5 in waste lime versus 0.08% S and 0.01% P2O5 in primary lime), utilization of these secondary lime materials could increase the S and P contents in the steel. The S content in the steel can be controlled during the reduction and desulfurization stages; however, the P content in the steel increases with an increased use of these secondary lime materials. Thirdly, the metallurgical performance of fly ash and waste lime is as good as primary lime when considering the aspects that: (a) utilization of fly ash and waste lime doesn’t have negative effects on the decarburization stage nor on the reduction stage during the AOD process; and (b) fly ash and waste lime are as efficient desulfurization agents as primary lime. In future industrial applications, the alkali content and the variations of chemical compositions (especially with respect to S, P and CaO) of these secondary lime materials need to be carefully controlled to ensure a sound metallurgical operation.

Optimization by mixture design approach

Purpose The purpose of this study is to fit an appropriate mathematical model to express response variables as functions of the proportions of the mixture components. One purpose of statistical modeling in a mixture experiment is to model the blending surface such that predictions of the response for any mixture component, singly or in combination, can be made empirically. Testing of the model adequacy will also be an important part of the statistical procedure. Design/methodology/approach A series of mortar using air lime, marble and ceramic sanitary waste aggregates were prepared for statistically designed combinations. The combinations were designed based on the mixture-design concept of design of experiments; this mortar is often used as a filler material in restoration projects. The aim of this work is to find an optimal composition of a paste for the manufacture of air lime mortar with ceramic and marble waste. This investigation aims to recommend mix design for air lime-based mortar, by optimizing the input combination for different properties, and to predict properties such as mechanical strength, thermogravimetric and x-ray diffraction analysis with a high degree of accuracy, based on a statistical analysis of experimental data. Findings This paper discusses those mortar properties that architects, contractors and owners consider important. For each of these properties, the influence of ceramic and marble waste in the air lime mortar is explored. The flexibility of lime-based mortars with waste materials to meet a wide range of needs in both new construction and restoration of masonry projects is demonstrated. Originality/value The objective of the present investigation is to recommend mixture design for air lime mortar with waste, by optimizing the input combination for different properties, and to predict properties such as compressive strength, flexural strength with a high degree of accuracy, based on the statistical analysis of experimental data. The authors conducted a mixture design study that takes into account dependent parameters such as the constituents of our air lime-based mortar where we have determined an experiment matrix to which we have connected the two responses, namely, compressive and flexural strength. By introducing the desirability criteria of these two responses, using JMP software, we were able to obtain a mixture optimal for air lime mortar with ceramic and marble waste.

Durability Performance of Binary and Ternary Blend Self Compacting Concrete using Waste Marble Powder and Lime Powder

Investigation practicing waste marble powder and lime powder as cement supplements in Self-compacting concrete (SCC) has obtained positive outcomes newly. In this research, waste marble powder (MW) and waste lime powder (LW) with the different combinations used in the design of SCC by replacement of cement 0, 10, 15 and 20%. In addition, 5% H2SO4 and 5% MgSO4 practiced for durability study and evaluate the effect of Sulfate attack and acid attack on filler content of mix after 28, 56, and 90 days curing of SCC sample. The results of the visual assessment and weight loss revealed that the increase in the amount of LW would enhance the performance of concrete, while the inclusion of LW and MW in SCC has shown positive results in terms of resistance against acid and sulfate attack. The mixtures with ternary binders of OPC, MW, and LW experienced the lowest strength loss after exposure to high concentrations of sulfate attack compared to unblended SCC.

Vermiculite-Lizardite Industrial Wastes Promote Plant Growth in a Peat Soil Affected by a Cu/Ni Smelter: a Case Study at the Kola Peninsula, Russia

Some industrial barren areas are extreme habitats created by the deposition of airborne pollutants from non-ferrous smelters. One of such barrens exists in the vicinities of the Cu/Ni smelter, located at the Kola Peninsula, Murmansk region, Russia. This study aimed at evaluating in laboratory conditions the efficiency of various vermiculite-lizardite wastes (industrial wastes of local origin) as soil amendments for plant growth promotion. Peat topsoil (0–20 cm) was collected in the vicinity of the Cu/Ni smelter. Total soil concentrations were 1612, 1481, and 63 mg kg−1 for Ni, Cu, and Co, respectively, and soil pH was 4.3. Soils were amended with lime waste and different types of vermiculite-lizardite wastes (coarse, fine, and thermo-activated at 700 °C), leaving one soil untreated. Weekly wetting-drying cycles, performed during 1 month, allowed amendments to react in the soil. All soils were cultivated with Lolium perenne L. for 21 days under controlled conditions. The plant growth was not influenced by high soil Cu concentration, while Ni and Co caused phytotoxicity. A mix of 10% (w/w) of different vermiculite-lizardite wastes with 10% (w/w) of lime improved the plant growth. Thermo-activated waste showed the best results for promoting plant growth and reducing foliar Ni concentrations from 1022 to 88–117 mg kg−1. However, the plants presented Ni phytotoxicity even in the amended soils and this requires further studies to find a way to reduce it.

Waste anthropogenic minerals in the circular economy

The article presents the possibility of using calcareous wastes to produce alternative sorbents for flue gas desulphurization. Calcareous wastes from chemical plants produced during the propylene oxide production process were used. In order to assess the potential of stored waste, they were subjected to comprehensive physical and chemical tests: the chemical, morphological, structural, fractional composition and reactivity were determined. Due to the nature of its formation, lime waste was subjected to electromagnetic activation to improve its sorption properties. The impact of activation on physico-chemical properties was also determined. The verification of the tests carried out on a micro scale was the flue gas desulphurisation test performed on a real object using the activation technology in an electromagnetic mill. The aim of the test was to obtain similar results of flue gas desulphurisation with the use of a waste sorbent for the lime milk used in this method.

Physico-mechanical characterization of sintered glass-ceramics fabricated from iron oxide added waste soda lime glasses

This study aims to highlight the sinter-crystallization behavior and mechanical properties of the glass-ceramics prepared from modified soda lime waste glass. To this purpose, different amounts of iron oxide (Fe2O3) (5-15 weight ratio) were added to the soda lime waste glass. The obtained mixtures were then melted and transformed into the glass-ceramics after a one-step sinter/crystallization heat treatment. According to the obtained results, wollastonite (CaO.SiO2) and diopside (CaO.MgO.2SiO2) precipitated in the sintered specimens, simultaneously or separately, depending on the content of iron oxide. On the basis of dilatometry analysis and the Huggins-Sun measurements, addition of iron oxide into the glass composition and its further addition increased the number of non-bridging oxygens and consequently decreased the glass viscosity. The glass-ceramics sintered at 850 °C showed the negligible water absorption and considerable content of the precipitated crystalline phases. Among them, the glass-ceramic Base-10F (containing 10 weight ratio of iron oxide) was considered as the most promising specimen due to its high mechanical strength (96 MPa), Vickers micro-hardness (491 VHN) and near zero water absorption.

Hydrogen and Methane Production Under Conditions of Anaerobic Digestion of Key-Lime and Cabbage Wastes

In this article, the results of key lime fruit (Citrus aurantifolia) wastes and cabbage (Brassica L.) wastes anaerobic digestion are presented. Anaerobic digestion of the wastes was performed in batch process, neutral pH (key-lime 7.47 and cabbage 7.67) and substrate concentration of Volatile Suspended Solids (VSS) 10 gVSS/L. One of the aims of this research was to check the availability of these substrates to be the source of methane and hydrogen. Key lime wastes produced 32 times more methane than raw cabbage. However, hydrogen production from cabbage was 149 times higher than key lime. The percentage of methane production in cabbage was up to 81% and in key lime was up to 75%. This research showed from the substrates comparison that efficient hydrogen production is less dependent on low pKa, pH than on total solids of the substrates.

Low CO2 emission cements of waste glass activated by CaO and NaOH

Abstract The recycling of Silica soda lime waste glass (WG) as a precursor of low emissions alkaline cements activated with CaO and NaOH was investigated in pastes and mortars. The experimental factors were the WG surface area, curing temperature, Na2O %wt. and %CaO wt. %, each with 3 levels using an experimental design based on orthogonal arrays. The use of CaO favored the reactivity of the WG in combination with Na2O; the CaO reduced the demand for Na2O to create an alkaline environment that promoted the dissolution of WG and provided Ca2+ for the formation of cementitious hydrated calcium silicates. The mortars showed hydraulic behavior and increasing strengths greater than 15 and 29 MPa after 28 and 180 days, respectively. The formation of the calcium silicate hydrates intermixed with silica gel was evidenced by energy dispersive spectroscopy, with reaction products of Ca/Si ratios of 0.35–0.75 for pastes, while 29Si Nuclear magnetic resonance indicated the formation of chain structures with a predominance of Q2 signals. Waste glass is an abundant promising precursor for new green cements, which creates a sustainable and simpler route to revalorize large volumes of this urban and industrial waste.

Preparation of geopolymer insulating bricks from waste raw materials

Insulating geopolymer samples were prepared from cheap sources, namely, the powder residue from the production of clay bricks (clay bricks waste), slaked lime waste from acetylene production and waste aluminum trimmings from workshops. 0.5% caustic soda was used, together with slaked lime as alkaline activator. De-aluminated kaolin, a waste from the alum industry, was also added as binding agent to substitute part of the clay bricks waste. Hydrogen produced from reaction between aluminum and alkalis induced the formation of pores inside the geopolymer matrix. It was found that using 5% (by weight) aluminum trimmings and substituting 15% of clay bricks waste by de-aluminated kaolin was enough to raise the porosity above 50%, thus producing light bricks of densities in the 1000 kg.m−3 range. The compressive strength of these bricks was about 1.4 MPa and their thermal conductivity as low as 0.26 W.m−1.K−1.

Modeling CBR Value using RF and M5P Techniques

Two modeling techniques namely (i) Random forest (RF) and (ii) M5P model tree are used to model, soaked California bearing ratio (CBR) value of thermal power plant generated stabilized pond ash. Pond ash was stabilized with the help of commercially available lime and industrial waste lime sludge. CBR data generated from exhaustive experimental programme was used in the study. Variations in doses of stabilizer i.e. lime (L) and lime sludge (LS), curing duration (CP) and proctor test results density (MDD) & moisture (OMC) are considered as input variables. Experimentally observed CBR value was used as output variable. Performance of models was measured using standard statistical parameters. Although, both the model’s performance in predicting CBR value is satisfactory however from the statistical parameters it is evident that RF method perform better in comparison to M5P model. Sensitivity analyses identify CP as the most influencing factor that affects CBR value of the stabilized pond ash.

Potential of using Waste Lime Sludge from Sugar Refinery as Binder in the Production of Earthenware Ceramics

Potential of using Waste Lime Sludge from Sugar Refinery as Binder in the Production of Earthenware Ceramics

Investigation of tannery liming waste water using green synthesised iron oxide nano particles

ABSTRACTThe present study aimed that non-toxic, less expensive, easily available, safer to environment and previously unreported Eclipta prostrata leaf extract is used for the green synthesis of iron oxide nano particles. The iron oxide nanoparticles (NPs) were characterised by UV–visible, Fourier Transform Infrared Spectroscopy (FTIR), scanning electron microscopy (SEM) with energy dispersive X-ray analysis (EDX), X-ray diffraction (XRD) and transmission electron microscopy (TEM). Tannery effluents treated by photodegradation process and the removal efficiency of chemical oxygen demand (COD), biological oxygen demand (BOD) and sulphide were analysed. The maximum removal efficiency correlated with operating parameters was explained using response surface methodology with Boxmen Beckmen design.

Fruit waste management by pigment production and utilization of residual as bioadsorbent

Dry powder of fruit wastes including pomegranate, grapes, lime, apple, and papaya was used to examine their pigment extraction capability. Solvent combination of hexane and acetone (1:1) produced the maximum extraction for lime waste with a yield of 1.65%. Gas Chromatography and Mass Spectrometry analysis of the crude pigment of lime exhibited the abundance of compounds like chlorogenic acid, caffeic acid, and coumaric acid. Three major bands were obtained in Thin Layer Chromatography. Column Chromatographic purification using ethyl acetate and hexane mixture as eluting phase showed a retention factor of 0.62 for the major band. Nuclear Magnetic Resonance revealed the final structure of the compound as chlorogenic acid. Slight inhibition was exhibited by the compound against Escherichia coli. Adsorption of arsenate by residual fruit waste revealed the highest adsorption in grapes with 92% efficiency. This study enlightens an alternative approach of fruit waste management with the production of value-added products and its utilization of residue as bioadsorbent.

Effect of Aging on Characteristics of Bitumen Modified with Waste Lime Sludge

Abstract The design of pavement must be carried out to make it capable of evenly transferring the wheel load to the subgrade soil without exceeding its bearing capacity. However, failure occurs before the design life because of structural defects shown by pavements, such as low skid resistance, fatigue, and rutting. Because low-temperature cracking is more predominant in cold-temperature regions, this aspect of failure is considered within the future scope of study. To address this concern, waste lime sludge was added to improve the properties of bitumen in the present research work. In order to examine the effect of aging, the rolling thin-film oven test was conducted to replicate the short-term aging process, and pressure aging vessel test was used to resemble long-term aging. The viscosity test, softening point test, and penetration test were carried out to assess the physical properties, whereas the dynamic shear rheometer test was conducted to investigate the rheological properties of aged and unaged bitumen binders. It is observed that sludge acts as an aging inhibitor. The complex modulus was enhanced as a result of addition of sludge up to 20 %, which also lowered the values of phase angle, depicting high resistance to permanent deformation. The rutting and fatigue resistances of the binder improved, and soft grade bitumen was converted to hard grade bitumen.

Impact of carbonatation lime addition on composting of vegetable oil refining sludge

The aim of the present work is to evaluate how the vegetable oil refining sludge produced by the agro-food industry could be composted using carbonatation lime and green waste as bulking agents. To achieve this goal, three windrows were prepared with different mixtures: windrow 1 contained oil sludge and green waste (20:10 on a wet mass basis) while windrow 2 contained oil sludge, green waste and carbonatation lime (20:10:10, on a wet mass basis). The composition of windrow 3 was: oil sludge, green waste and carbonatation lime (20:10:20, on a wet mass basis). The results showed that the use of carbonatation lime for composting vegetable oil refining sludge was able to regulate the high acidity of the sludge and thus to obtain an optimal pH value for the launching and maintenance of the composting process. The addition of carbonatation lime also gave better reduction of microbial activity without any negative effect on composting. The compost prepared with oil refining sludge (49% fresh mass), carbonatation lime (27%) and green waste (24%) exhibited the best quality with C/N ratio and pH values within the norm NFU44-051. These promising results could be a sustainable solution for the valorization of both oil refining sludge and sugar carbonatation lime.

Adsorptive Removal of Fluoride from Aqueous Solution by Biogenic Iron Permeated Activated Carbon Derived from Sweet Lime Waste

In this study, biogenic activated carbon were successfully synthesized from Citrus limetta pulp residue, and applied to remove fluoride from an aqueous solution. For the synthesis activated carbon of biosorbents, raw materials were heated in muffle furnace at two different temperatures i.e. (250 °C and 500 °C) and were noted as ACP-250 and ACP-500. The prepared biosorbents were characterized through scanning electron microscopy (SEM), Fourier transform infrared (FTIR), and X-ray diffraction (XRD). Batch adsorption studies were performed with varying temperature, dosage, pH, and various initial concentrations. Adsorption isotherms and the reaction kinetics were also analyzed in order to understand the adsorption mechanism. The results of this study shows that the maximum removal achieved was approximately (86 and 82) % of ACP-500 and ACP-250, respectively. The isotherm results show that the Langmuir isotherm model fitted better, with monolayer adsorption capacity of 12.6 mg/g of fluoride. However, for kinetic study, the pseudo-second-order kinetics fitted well. The synthesized materials at different temperature were highly effective for the removal of fluoride from water, with reusability of three to four times.

Utilization of Carbide Lime Waste as Base Catalyst for Biodiesel Production

Calcium rich solid base catalyst was synthesized from local waste carbide lime and its catalytic performance was evaluated via biodiesel production. Carbide lime waste was used to produce CLW-I and CLW-II solid base catalyst using different preparation methods. Characterization including base strength analysis, scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD) were investigated. Catalytic strength was examined by deploying the solid base catalysts for transesterification reaction of palm oil. Fourier Transform Infra-red (FTIR) was used to analyze the presence of ester group in biodiesel. The yield of biodiesel conversion was calculated based on the mass of biodiesel and glycerol. The highest biodiesel conversion rate of 75.30% was achieved by CLW-I solid base catalyst at 9% loading. The good catalytic performance of carbide lime waste derived solid base catalysts proves that it has high potential to replace the usage of conventional catalyst in the biodiesel industry.