Effect Of Lime Treatment Research Articles

Experimental study on strength characteristics and internal mineral changes of Lime-stabilized loess under High-Temperature

• Effect of lime treatment on compression and shear strength of loess were studied. • Tests were carried out at a wide temperature range (30 ∼ 300 °C) and 5 lime contents. • Treatment with lime improved the strength of loess at high-temperatures. • Multiple methods XRD, TGA, DSC reveal the mechanisms of the lime-loess reactions. In this study, lime-stabilized loess with five lime contents (0 %, 3.5 %, 7 %, 10.5 %, and 14 %) treated at four temperature levels (30 °C, 100 °C, 200 °C, and 300 °C) were tested for 48 h in a series of laboratory experiments to investigate the mechanical strength characteristics and internal mineral changes of lime-stabilized loess under high temperature. The unconfined compressive strength (UCS) tests and shear box test results show that the compressive and shear strengths of lime-stabilized loess are larger than those of plain loess, not only at room temperature but also at high temperatures. Under the same lime content, the mechanical strength of each sample was greatly improved after high-temperature treatment. As the heat-treatment temperature increased within the test temperature range, the compressive and shear strengths gradually improved. These mechanical strength test results prove that adopting lime-stabilized loess as the building material for structures vulnerable to high temperatures is feasible. When compressive and shear strengths were selected as the evaluation criteria for determining the lime content, the optimal lime content in this study was 7 %. X-ray diffraction and thermal analysis test results revealed that the strength enhancement of lime-stabilized loess is mainly derived from the lime slaking reaction, pozzolanic reaction, and crystallization reaction. High-temperature treatments can promote the reaction rates of these processes.

Evaluation of lime products for clubroot (Plasmodiophora brassicae) management in canola (Brassica napus) cropping systems

Clubroot, caused by Plasmodiophora brassicae, is an important soilborne disease of canola (Brassica napus) in Alberta, Canada. As clubroot prefers acidic soils, the application of lime to increase soil pH may reduce disease. Replicated field plot experiments were conducted to evaluate the efficacy of hydrated lime for clubroot management. In 2017, moderate (11.4 t ha−1) to high rates (12.7 t ha−1) of hydrated lime reduced the index of disease (ID) by 35–91% in a susceptible canola cultivar 8 weeks after seeding. In contrast, no effect of lime treatment was observed in the 2018 field trials, due to several environmental factors. A greenhouse study compared the efficacy of hydrated lime and limestone in reducing ID in susceptible and resistant canola cultivars, at different application rates and inoculum concentrations. In treatments that did not receive lime, ID was very high (92–100%) in the susceptible and low (9–13%) in the resistant canola. The application of hydrated lime at 4.7, 8.1, 11.4 and 14.8 t ha−1 eliminated visible symptoms in both cultivars, whereas limestone reduced the ID only at the two lowest inoculum concentrations. Root tissues from the same study were analyzed by quantitative PCR to measure P. brassicae proliferation in planta. Inoculum concentration and the type and rate of lime significantly affected the amount of P. brassicae DNA present in the root tissue. Repeated trials with less virulent inoculum indicated similar trends. Hydrated lime may represent a more effective tool than limestone to manage P. brassicae on canola in highly infested soils.

Differences of Giving Calcite And Dolomite to the Myselium Growth

White Oyster Mushroom (Pleurotus ostreatus (Jacq. Ex. Fr) Kummer) is a type of wood fungus that has a higher nutrient content than other types of mushrooms and is in great demand in Indonesia. For the growth of oyster mushroom mycelium, Calcite and dolomite are used. Dolomite and Calcite have the ability to accelerate mold growth. The purpose of this study was to determine the differences in the correct dose of Calcite and dolomite for the growth of mycelium white oyster mushrooms. This research was conducted at the Medan Oyster Mushroom Joint Venture, North Sumatra using F2 seeds from oyster mushrooms obtained from the research location. This study used an experimental method with 2 studies with research I (namely the effect of lime treatment) and research II (the effect of dolomite treatment) with 4 treatments and 6 replications respectively.10 grams of Calcite and 30 grams of dolomite is the optimum dose for the growth of white oyster mushroom mycelium

CO2 fluxes from aquaculture ponds of a tropical wetland: Potential of multiple lime treatment in reduction of CO2 emission

Partial pressure of CO2 in water [pCO2(water)] and air-water CO2 flux were estimated in two aquaculture ponds (one received no lime treatment (NTP) and in the other lime treatment was performed (LTP) four times a year) every month throughout an annual cycle, situated in East Kolkata Wetlands, a Ramsar Site in eastern India. It was hypothesized that lime treatment can potentially lower the pCO2(water) in aquaculture ponds and hence make these aquatic bodies sinks for CO2. The results portrayed that NTP acted as a source of CO2 throughout the year (annual mean: 1929 ± 1397 μmol m−2 h−1), whereas, LTP acted as CO2 sinks post lime addition (monthly mean ranged from −366 ± 16 to −449 ± 32 μmol m−2 h−1), though the effect of lime addition was found to diminish by the next month and it acted as source for CO2 in the months when no lime treatment was done (LTP annual mean: 1010 ± 1617 μmol m−2 h−1). Lime treatment increased the pH level and reduced the turbidity which facilitated optimum photosynthesis and the productivity increased rapidly. Beyond the critical pH value of 8.9–9.0, the pCO2(water) values became under-saturated with respect to atmospheric CO2 concentration. The effect of lime treatment was not found to prevail in the following months as a steady source of sewage from the Kolkata metropolis which feeds these aquaculture constantly bring in a huge carbon source both in inorganic and organic form. As soon as the flocculation effect of the lime dies off, the water column starts becoming turbid again which aids in converting the system into a net heterotrophic one from a net autotrophic. Based on the results we could successfully accept our hypothesis that lime treatment can not only reduce the CO2 emission but also make the system a CO2 sink.

Effects of lime treatment on the geotechnical properties of dredged mud

The preloading method has been widely applied in land reclamation as a green and economical approach to ground improvement. To improve the consolidation behavior, the addition of lime generally improves soil performance. In this article, a modified oedometer equipped with a tactile pressure sensor and a bender–extender element is employed. The effects of lime treatment on the geotechnical properties of dredged mud are investigated; these properties include the coefficient of the earth pressure at rest (K0), settlement, drainage behavior, and evolution of the elastic wave velocity. The results reveal that the addition of lime not only influences the specimen’s deformation behavior but also influences its shear strength during and after loading. Combined with the evolution of the elastic wave velocity, the microstructural evolution of the specimen could be described and explained. It is concluded that a compressional wave is more sensitive to the change in the specimen’s void ratio and saturation. For K0, initially (<25 kPa), the higher the lime content is, the greater the K0 fluctuation is. Afterwards, the higher the lime content is, the smaller the K0 fluctuation is, and finally K0 slowly approaches approximately 0.2.

Effects of lime treatment on the hydraulic conductivity and microstructure of loess

Lime treatment of loess in foundation engineering modifies the soil structure, leading to changes in mechanical and hydraulic properties of soil, which in turn will affect the flow of water and transport of contaminants in the loess. In light of this, it is essential to identify the dominant effects of different lime treatments on hydraulic conductivity, and to ascertain the optimum lime treatment. For this purpose, we investigated the effects of dry density and lime content on changes in hydraulic conductivity and microstructure of loess in Yan’an City, China. The results indicate that hydraulic conductivity has a log negative correlation with dry density, and lime addition can result in a decrease of hydraulic conductivity of loess at the same dry density. Under a given degree of compaction, however, lime addition can lead to a decrease in dry density due to an increase in flocculation and aggregations. The significant decrease of dry density leads to an increase in hydraulic conductivity when lime content (in mass percentage) is lower than 3%. Nevertheless, when lime content is higher than 3%, the reactions between loess particles and lime will be intensified with an increase in lime content, and become the primary factors affecting pore characteristics. These reactions can further decrease the hydraulic conductivity of lime-treated loess, and the lowest hydraulic conductivity was obtained for lime-treated loess with 9% lime content. The excess lime (above 9% lime content) dramatically increased pore size, leading to a significant increase in hydraulic conductivity. Therefore, 9% is the optimum lime content for loess treatment, and the degree of compaction in engineering should be higher than 95%. In addition, statistical analysis of microstructure of lime-treated loess shows that the distribution trends of macro- and meso-pores coincided with that of saturated hydraulic conductivity, which indicates that lime content affects saturated hydraulic conductivity of lime-treated loess by changing the soil structure, especially the properties of pores larger than 8 µm.

Effects of lime treatments on marls

Marly clay was treated with calcitic and Mg-rich lime in order to determine the influence of the clay's high carbonate content on the stabilization effectiveness. The evolution of mineralogical and physical properties over the course of the treatment were studied using XRD, TEM, SEM, elemental analysis, TG, granulometry, and nitrogen sorption and correlated with the marly clay's improved geotechnical behaviour. Only a small portion of smectites and other clay minerals dissolved upon lime treatment. Changes in clay mineralogy had, thus, only very limited influence in the improvement of the material's plasticity and swelling behaviour, which was rather modified by an increase in particle size. This increase was primarily caused by aggregation induced by calcium silicate aluminium hydrate (C-(A)-S-H) formation, whereas flocculation had an only minor effect. After the initial improvement, disaggregation of clay particles occurred which resulted in a particle size decrease, most likely, caused by carbonation of C-(A)-S-H phases. These findings question the effectiveness of lime stabilization for marl using currently applied standard treatment protocols.

Effect of liming on soil nitrogen loss in runoff from a cultivated bamboo stand

Liming is an effective method of mitigating soil acidification. However, the effect of lime treatment on soil nitrogen (N) loss through runoff from fields remains unclear. A bamboo stand (<i>Phyllostachys praecox</i> C.) with high N content and severe acidification was selected to investigate the effect of liming on soil N loss through runoff. A laboratory experiment was conducted to determine the liming effect on N mineralization and pH using the recommended liming rate in field. Results showed that soil pH increased from 3.1 to 5.6 and soil nitrification rate significantly improved when a liming rate of 10 Mg ha⁻¹ (3.98 tn ac⁻¹) was applied in the field. The total dissolved N (TDN) concentration in the runoff ranged from 1.98 to 41.6 mg L⁻¹ in the nonliming treatment and from 1.98 to 33.3 mg L⁻¹ in the liming treatment. The event mean concentrations (EMCs) of TDN in the plots of the liming and nonliming treatments were 5.80 and 6.72 mg L⁻¹ (<i>p</i> &lt; 0.05), respectively. Total N loss through runoff was reduced by liming from 12.4 to 10.6 kg ha⁻¹ (11.0 to 9.44 lb ac⁻¹; <i>p</i> &lt; 0.05) at a rate of 14.5%. Runoff in the field mainly occurred in summer season, and N loss in nitrate (NO₃) form accounted for approximately 70% of TDN. The high N uptake by bamboo plants and increased ammonia (NH₃) volatilization may be attributed to the decline of TDN in the liming treatment compared with those in the nonliming treatment. Results indicated that a reasonable liming rate in an acid-cultivated land can benefit crop production and nutrient loss control.

Effect of alkaline treatment and storage qualities of maize flour

An attempt was made to study the effect of lime treatment, packaging materials and storage periods on biochemical qualities of CO1 and HQPM 7 maize varieties flour. The flours were treated with calcium hydroxide, packed in the two packaging materials viz., polyethylene bags (P1) and metalized polyester polypropylene laminated bags (P2) and its biochemical qualities were determined at 15 days storage intervals of 90 days storage. It was found that an increase in moisture content was noticed during storage but it was lesser in the lime treated flour compared to the untreated maize flour of both varieties. In P2 package, moisture content was significantly lower in compared to P1. The free fatty acid and peroxide value increased on storage but the changes were minimum in samples packaged in P2. Biochemical qualities of maize flour showed that lime treated maize flour can be stored for a longer period compared to untreated maize flour in the both the varieties.

One-dimensional consolidation of lime-treated dredged harbour sediments

Dunkirk marine sediments can be used as an alternative roadbed material, and a full-scale test road using this has been successfully built at Dunkirk harbour in France. In this context, the long-term deformation behaviour of Dunkirk sediments is of crucial importance in the evaluation of roadbed deformation. The standard oedometer tests were carried out to plot the e-logσ′ and e-logt curves, which were used to determine the compression index (Cc), swelling index (Cs) and coefficient of secondary compression Cα during loading and unloading. The effect of lime treatment on primary and secondary compression behaviour was investigated. The soil structure influences greatly the yield consolidation stress σy′, which is increased with lime content. Both σy′–ey (void ratio at σy′) and Cc–Cs relations are analysed. It is observed that σy′ is connected with ey by a power function and Cc/Cs varies between 0.013 and 0.1. Cα remains low at consolidation stress σ′ < σy′ and reaches a peak at σ′ = (1 – 4) σy′ followed by a decrease in Cα. Lime addition induces the peak Cα moving towards a larger consolidation stress of 5σy′. Based on the Cα–lg(t/tp) curves, it is interesting to note that t = 20tp (end-of-primary consolidation time) is suggested as a sufficient consolidation time to study the secondary compression behaviour of marine sediments. The Cα/Cc ratios of various clays including Dunkirk sediments show that Cα/Cc changes mainly in the range of 0.02–0.05. However, the Cα/Cc ratio is different for lime-treated sediments (Cα/Cc* = 0.0164) and untreated sediments (Cα/Cc* = 0.0432). Two separate zones in Cα–Cs* plot are clearly observed for untreated and treated sediments with boundary line of Cα = 0.0433Cs* – 0.0008.

Effect of lime treatment on geotechnical properties of Dunkirk sediments in France

The increasing cost associated with high-quality materials has lead to the need for sediments to be treated and then used in road construction in the context of durable development. Therefore, the modification and stabilisation of Dunkirk marine sediments by using lime is necessary to study for their potential use in road construction. Based on the physical characteristics of untreated sediments, a series of laboratory tests to investigate the geotechnical properties of untreated sediments and lime-treated sediments, such as unconfined compressive strength tests, standard oedometer tests, direct shear tests and triaxial tests, were performed. Lime was added in percentages of 3% and 6%, by weight of dry sediments. The test results show a significant improvement in unconfined compressive strength and shear strength due to the addition of lime. From the strain–stress relationship of compressive strength tests, it can be found that the failure mode of solidified sediments develops gradually from plastic failure to brittle failure, while the failure strength increases and the failure strain decreases with lime content. Compared with untreated sediments, the shear strength parameters of solidified sediments determined by direct shear tests, such as internal friction angle and cohesion, are increased owing to the pozzolanic reaction between lime and clay minerals. Using the oedometer apparatus, it is observed that after lime treatment, the preconsolidation pressure, the coefficient of consolidation and the compression index are increased, while the swelling index is decreased. The characteristics of the deviator stress–axial strain relation and the pore water pressure distribution under different confining stresses are compared with untreated and treated sediments, and the effect of lime content on cohesion and internal friction angle determined by triaxial tests is discussed.

Effect of Accelerated Loading on the Compressibility Characteristics of Lime-Treated Semiarid Soils

AbstractDetermination of consolidation properties of compacted lime-treated cohesive clays by the one-dimensional fixed-ring oedometer consolidation method with conventional load increment duration may not be appropriate due to immediate pozzolanic reactions, which occur in the presence of lime. An attempt has thus been made to study the effect of accelerated loading on the compressibility characteristics of two different cohesive clays originating from diversified terrains of Saudi Arabia, before and after treating them with lime. In order to study the extent of improvement on the strength characteristics upon lime treatment, a series of unconfined compression strength tests are also carried out. The effect of lime treatment on the elastic moduli has also been studied. It is observed that, prior to any treatment, the final equilibrium void ratio values increase with the increase in duration of loading for the soils. The addition of lime significantly affects the compressibility behavior of both the soils...

Evaluation of Bioaerosol Components, Generation Factors, and Airborne Transport Associated with Lime Treatment of Contaminated Sediment

Lime treatment has been used in contaminated sediment management activities for many purposes such as dewatering, improvement of physical properties, and reducing contaminant mobility. Exothermic volatilization of volatile organic compounds from lime-treated sediment is well known, but potential aerosolization of bioaerosol components has not been evaluated. A physical model of a contaminated sediment treatment and airborne transport process and an experimental protocol were developed to identify specific bioaerosol components (bacteria, fungi, cell structural components, and particles) that may be aerosolized and transported. Key reaction variables (amount of lime addition, rate of lime addition, mixing energy supplied) that may affect the aerosolization of bioaerosol components were evaluated. Lime treatment of a sediment contaminated with heavy metals, petroleum-based organics, and microorganisms increased the sediment pH and solids content. Lime treatment reduced the number of water-extractable bacteria and fungi in the sediment from approximately 106 colony-forming units (CFU) · mL-1 to less than the detection limit of 103 CFU • mL-1. This reduction was seen immediately for bacteria and within 21 days for fungi. Lime treatment immediately reduced the amount of endotoxin in the sediment, but the effects of lime treatment on β-D-glucan could not be determined. The temperature of the treated sediment was linearly related to the amount of lime added within the range of 0–25%. Bacteria were aerosolized during the treatment trials, but there was no culturable evidence of aerosolization of fungi, most likely because of either their particular growth stage or relatively larger particle size that reduced their aerosolization potential and their collection into the impingers. Nonbiological particles, endotoxin, and β-D-glucan were not detected in air samples during the treatment trials. The amount of lime added to the reaction beaker and the relative amount of mixing energy supplied to the reaction significantly affected the aerosolization ratio of bacteria (amount of aerosolized bacteria divided by the amount of bacteria in untreated sediment) from the reaction beaker. The rate of lime addition did not significantly affect the aerosolization ratio of bacteria. The aerosolization results suggest that exposure to bacteria is possible with sediment treatment activities, but the hazard level could not be determined because speciation of the aerosolized bacteria for pathogen identification was not performed, and health and safety standards and criteria for bioaerosol components have not been developed. Quantitative scaling analysis and whether the system represents actual environmental conditions were not studied.

Effects of single Ca(OH)2 doses on phosphorus concentration and macrophyte biomass of two boreal eutrophic lakes over 2 years

1. Two hardwater eutrophic lakes of central Alberta were subjected to single doses of Ca(OH)2 (74 or 107 mg L–1). The effects of lime treatment on phosphorus (P) precipitation, sediment P release, and macrophyte biomass were assessed for up to 2 years.2. In both lakes, sediment P release was reduced to 16 and 27%, respectively, of pre‐treatment values by the first winter following treatment. However, sediment P release returned to pre‐treatment values during the following year.3. In contrast to these short‐term effects, macrophyte biomass decreased by as much as 80% after lime application and remained there for at least 2 years.4. Our results indicate that a single dose of Ca(OH)2 may give short‐term (&lt; 1 year) control of P and long‐term control (&gt; 1 year) of macrophytes in hardwater eutrophic lakes of Alberta.

Characterization and lime treatment of olive mill wastewater

Seventeen olive mill wastewater (OMW) samples were characterized. For characterization of the samples, amount of total, fixed, volatile, suspended, volatile-suspended solids, COD, oil-grease, polyphenol, volatile phenol, nitrogen and reducing sugar were determined. Effects of lime treatment on the waste samples were investigated. Reduction of contents of the samples treated with the lime was described. The effect of the addition of lime on an artificial phenolic mixture was also examined.

Effects of lime treatment on fractionation and extractabilities of heavy metals in sewage sludge

Many studies have focused on heavy metal characteristics in sewage sludges and sludge‐amended soils other than lime‐stabilized sewage sludge (LS). Thus, the aerobically digested sewage sludge cake (13.61% solids) sampled from the Min‐Sheng Wastewater Treatment Plant in Taipei City, Taiwan was lime‐stabilized for studying the effects of the lime treatment on fractionation and extractabilities of heavy metals (Cu, Pb, Cr, and Zn) in sewage sludge, using various extraction tests. For comparative objective, oven‐dry sewage sludge without liming (unlimed sludge (S)) was also studied. The results of this study revealed that the percentages of the metals extracted from lime‐stabilized sludge (pH = 12.05) and the amounts of the metals fractionated to the organically‐bound fraction (30% H2O2 + 0.02 M HNO3 (pH2), 85°C) in unlimed sludge were both in the order of Cu > Pb > Cr > Zn, meaning that the more the heavy metals (e.g., Cu) were fractionated to the organically‐bound forms in unlimed sludge, the more unstable they were in the sludge after lime‐stabilized. On the other hand, the metals (e.g., Zn) in lime‐stabilized sludge was more stable when they have less affinity for organics. Single extraction conducted at various pHs revealed that this effect was due to the irreversible dissolution of organics and some metals having a higher affinity for organics (e.g., Cu) at very high pH during processing and air drying of lime‐stabilized sludge. Therefore, examining the fractionation of heavy metals in sewage sludge is useful for expecting heavy metal stability in the sewage sludges after lime‐stabilized.

Sludges from cold regions lagoons

Accumulated solids associated with the operation of aerated and facultative lagoons in cold climates were investigated to determine (1) the rate and extent of solids accumulation, (2) the characteristics of the accumulated solids, (3) the potential for in situ stabilization of the accumulated solids, and (4) the effect of lime treatment upon the pathogenic population and subsequent solids drying on sand and soil beds. Accumulated sludges from the Logan and Corinne, Utah, facultative lagoons and the Palmer and Galena, Alaska, partial-mix aerated lagoons were studied. The rates of accumulation, determined by in situ measurement of the sludge layer in each lagoon, were found to vary with lagoon type and specific operational and environmental conditions.

Effects of liming on crayfish and fish in Sweden

The effects of lime treatment on crayfish (Astacus astacus and Pacifastacus leniusculus) populations in 17 lakes and fish populations in 47 lakes and 7 rivers within the trial period 1976–82 have been evaluated. An increase in the catch of crayfish per unit effort was observed in 7 lakes, although significantly in one lake only. The varying results in the other lakes indicate that factors other than pH may be of greater importance for the development of crayfish populations after liming. Recruitment of fish improved in waters where liming resulted in pH >5.5. In lakes with pH after treatment, there was a significant increase in the number of fish caught, from 12 to 34 per unit effort. Due to improved recruitment the individual average weight was smaller and hence the catch in weight per unit effort was about the same as before liming. After lime treatment in streams which resulted in a stable pH of >5.5, the abundance of juvenile salmonids increased to numbers found in non-acidified streams. In other streams acid spates reduced the positive influence of liming on the abundance of juvenile salmonids.

Effect of lime treatment on the resilent behaviour of fine-grained soils : Robnett, Q L; Thompson, M R US Transportation Research Board, Transportation Research Record 560, 1976, P11–20

Effect of lime treatment on the resilent behaviour of fine-grained soils : Robnett, Q L; Thompson, M R US Transportation Research Board, Transportation Research Record 560, 1976, P11–20

Lime-Heat Effects on Corn Nutrients, Effect of Lime Treatment on in Vitro Availability of Essential Amino Acids and Solubility of Protein Fractions in Corn

Lime-Heat Effects on Corn Nutrients, Effect of Lime Treatment on in Vitro Availability of Essential Amino Acids and Solubility of Protein Fractions in Corn