Статті в журналах з теми "SOIL-WATER CHARACTERISTICS CURE"

The objective of this paper is to investigate the influence of curing time on expansive soil as a construction material when treated with eco-cement stabilizer, as partly substituting the Portland cement. Standard consolidation samples were prepared from treated soils with 10 % cement (5% eco-cement and 5% Portland cement), reported to the dry unit weight of soil, and cured for 1, 7 and 14 days. After this period the soil samples were then socked in water and standard consolidation tests were performed on them. The compressibility characteristics, for the improved soil with 10% cement, Eoed, mv and Cv have shown a significant improvement during the first 7 days. After 7 days curing time the variation of compressibility characteristics is less pronounced.

Soil chemical stabilization is an effective yet comparatively economical ground improvement method which involves injecting or blending a binder into the existing soil to enhance the geotechnical properties (e.g. strength and stiffness) for load-bearing purposes. The technique is especially beneficial for road construction works on clayey soil of limited load-bearing capacity such as rural roads. It required thick road base is critical to ensure long-term stability and performance. An endeavour is therefore undertaken to examine the effectiveness of a proprietary fibre-mixed binder in stabilizing soils (sandy clay) nature to serve as road base material. Kaolin was mixed with sand as the base soil at ratios of 0, 25 and 50% sand addition. The fibre-mixed binder was added at dosages of 1.5, 2.5 and 3.5% as recommended by the proprietor. Standard compaction test was first carried out to determine the optimum water content for each kaolin-sand mix. Then left to cure for 1, 3, 7 and 28 days before subjected to the California Bearing Ratio (CBR) test. From the test results, it was found that 2.5% binder addition was sufficient to attain the minimum CBR requirement of 30% for supporting a conventional flexible pavement, as per JKR standard. However, the 100% clay sample required higher binder dosages. Clearly sand particles in the soil contributed to the formation of skeletal scaffolding of the soil matrix, bound and supported by the fibre-mixed binder for enhanced strength properties. This was evident in the compaction test where 50% sand addition reduced the optimum water content by almost half compared to the 100% clay. Moreover 3-day curing could adequately strengthen all samples to attain the minimum CBR requirement (JKR standard), irrespective of the binder dosage used. In conclusion, it could effectively strengthen sandy clay soils within 3 days with dosages as low as 2.5%.

Abstract Sands reinforced by hydraulic binders (cement) have constituted in recent decades a major asset for the expansion of several areas of engineering. The mechanical behavior of sand-cement mixtures has undergone some controversies studied on the Chlef sand. In this paper, we present an experimental study to investigate the mechanical behavior of a sandy soil reinforced by a hydraulic binder (cement), using the direct shear apparatus emphasizing on the shear strength characteristics and the vertical deformation variation of cemented reinforced sand. The parameters used in this study are mainly: relative density (Dr = 80%), normal stress (σn = 100, 200, 400 kPa), water content (3, 7 and 10%), cement content (2.5, 5, 7.5 and 10 %) and cure time (7, 14 and 28 days). The experimental results show that the mechanical characteristics in terms of internal cohesion (C) and internal frication angle (φ) give a better mechanical performance with the binder inclusion, and the cure conditions play an effective role on the improvement of the shear strength. This result also showed that 10% of the cement content gave us a maximum value of shear strength and an optimal influence on the mechanical characteristics. The addition of cement not only improves the shear strength of soil, but also provides diversity in the resistance against the deformations imposed load, which can be established by a dilatant character.

Abstract Sedimentary soil is made up of deposits that are the consequence of the weathering of rocks that have already been deposited elsewhere by various natural processes, including water, wind, and others. A location with sedimentary soil is the Bili-bili Dam in the South Sulawesi Province's Gowa Regency. Sedimentary soil at this location is quite abundant and has not been used in general, so it can be investigated for its use, namely stability against the influence of external forces on the carrying capacity of the sedimentary soil. Stabilizing the soil is one approach to boost its bearing capacity, particularly for sedimentary soil. The original soil is categorized as group A-4, or silty soil, according to the AASHTO classification system and as ML, or silt with low plasticity, according to the USCS classification system, based on the findings of physical characteristics testing. It has been demonstrated that the soil's cohesiveness and shear angle increase with the addition of fly ash. It has been demonstrated that adding fly ash stabilizing material to the sedimentary soil of the Bili-bili Dam and allowing it to cure increased the cohesion value from the initial soil cohesion value of 0.72 kg/cm2 to 1.70 kg/cm2 after 28 days. With a 20% fly ash mixture and a curing period of 28 days, the shear angle value increased from the initial soil shear angle value of 22 to 31; this is a 40% increase in the shear angle value.

DBD is an infectious disease by the Dengue virus, which is transmitted through the bite of Aedes aegypti mosquitoes. This disease's characteristics include sudden high fever accompanied by bleeding manifestations and the tendency to cause shock that can cause death. Until now, there is no cure for dengue fever or a vaccine. So the only way to prevent this disease is to break the chain of transmission. The main factor of dengue fever in Indonesia is the Aedes aegypti mosquito. Another way to avoid dengue fever is the correct 3M plus method, namely 1. Close, cover all places that can hold water, both inside and outside the house. 2. Drain, drain water reservoirs such as bathtubs, aquariums, and flower vases two times a week. The mosquito metamorphosis cycle, from egg to adult mosquito, lasts 8-10 days. 3. Bury. Bury all objects that can hold water, such as used cans or plastic containers. However, in the 3M movement, which has been renewed to 3M plus, this third M is no longer recommended because it can cause soil pollution

Soil hydraulic characteristics, especially the soil water retention curve and hydraulic conductivity, are essential for many agricultural, environmental, and engineering applications. Their measurement is time-consuming and thus costly. Hence, many researchers focused on methods enabling their indirect estimation. In this paper, Wösten’s continuous pedotransfer functions were applied to the data from a selected locality in the Czech Republic, Tišice. The available data set related to this locality consists of 140 measured soil water retention curves, and the information about the soil texture, bulk density ρ_d, and organic matter content determined at the same time. Own continuous pedotransfer functions were derived, following the methodology used in continuous pedotransfer functions. Two types of fitting, 4-parameters and 3-parameters, were tested. In 4-parameter fitting, all parameters of the van Genuchten’s equation, θ_s, θ_r, α, n, were optimized; in 3-parameter fitting, only three parameters, θ_r, α, n, were optimised while the measured value of θ_s was set as constant. Based on the results, it can be concluded that the general equations of Wösten’s pedotransfer functions are not very suitable to estimate the soil water retention curves for the locality Tišice in the Czech Republic. However, the parameters of the same Wösten’s equations, which were calculated only from the data for each particular locality, performed much better. The estimates can be improved if the value for the saturated soil water content θ_s is known, applied and not optimised (the case of 3-parameter fitting). It can be advantageous to estimate SWRC for a locality with no data available, using PTFs and the available basic soil properties. In addition, to measure some retention curves and/or some their parameters, like θ_s, can improve the accuracy of the SWRC estimation.

The special above-ground and underground dual structure in the karst area makes the capacity of surface water storage in this area poor. In water-limited ecosystems, soil moisture is the key to the survival of plants. Influenced by rainfall and soil texture, soil moisture variation characteristics of different vegetation types are different in slope land. Many researchers use rainfall simulation experiments to study the influence of soil water movement processes under rainfall patterns, but there are few studies under natural conditions. In this paper, wood trees, peach trees, flue-cured tobacco, and grassland were planted at the buffer zone boundary of Shibing, a World Heritage site, along different elevations in the depression of the research site. Peach trees and flue-cured tobacco were the main cash crops in the area. The soil layers of 0–0.15 m, 0.15–0.30 m, 0.30–0.45 m, 0.45–0.60 m, and 0.60–0.75 m were taken as research objects. Rainfall and soil moisture were monitored every ten minutes to study the variation of soil moisture of vegetation types under different rainfall patterns. Through the analysis of soil physicochemical properties and vegetation types, it was found that soil moisture changes were different in different land types. In general, shallow soil moisture (0~0.30 m) was more active in the wet season (CV > 10%) but tended to be stable in the dry season. The rainy season rainfall had the greatest influence on soil moisture change. The response level of soil moisture to rainfall of all vegetation types was grassland > peach trees > flue-cured tobacco. These results can provide ecological and economic suggestions for karst areas with large population distribution in China, so as to reduce the impact of rock desertification on this area.

Fly ash (FA) usually causes air and soil pollution due to wind erosion. However, most FA field surface stabilization technologies have long construction periods, poor curing effects, and secondary pollution. Therefore, there is an urgent need to develop an efficient and environmentally friendly curing technology. Polyacrylamide (PAM) is an environmental macromolecular chemical material for soil improvement, and Enzyme Induced Carbonate Precipitation (EICP) is a new friendly bio-reinforced soil technology. This study attempted to use chemical, biological, and chemical-biological composite treatment solutions to solidify FA, and the curing effect was evaluated by testing indicators, such as unconfined compressive strength (UCS), wind erosion rate (WER), and agglomerate particle size. The results showed that due to the viscosity increase in the treatment solution, with the increase in PAM concentration, the UCS of the cured samples increased first (from 41.3 kPa to 376.1 kPa) and then decreased slightly (from 376.1 kPa to 367.3 kPa), while the wind erosion rate of the cured samples decreased first (from 39.567 mg/(m2·min) to 3.014 mg/(m2·min)) and then increased slightly (from 3.014 mg/(m2·min) to 3.427 mg/(m2·min)). Scanning electron microscopy (SEM) indicated that the network structure formed by PAM between the FA particles improved the physical structure of the sample. On the other hand, PAM increased the nucleation sites for EICP. Due to the stable and dense spatial structure formed by the “bridging” effect of PAM and the cementation of CaCO3 crystals, the mechanical strength, wind erosion resistance, water stability, and frost resistance of the samples cured by PAM-EICP were increased significantly. The research will provide curing application experience and a theoretical basis for FA in wind erosion areas.

This study established a study framework to quantify the safety factors of unsaturated shallow slopes at different temperatures. This study is based on a non-isothermal soil water characteristic curve model quantifying the temperature-dependent hydraulic properties of soils. The hydraulic coupling analysis models HYDRUS 2D and The Slope Cube Module were used for finite element modeling. A slope stability analysis was performed based on the local factor of safety (LFS) theory. An increased temperature decreased the soil matric suction, suction stress, effective stress, and LFS, weakening the soil strength. Slope modeling analysis showed that soils were dominated by different water retention mechanisms before and after rainfall infiltration, and the trends caused by temperature changes also changed accordingly. This study provides insights into the relationship between soil mechanical properties and temperature, which is valuable for maintaining soil stability and preventing geological hazards.

This study was conducted to evaluate the strength and volume change characteristics of a sedimentary residual soil mixed with bentonite (S1) when treated with three different enzymes. In addition, three reference clays including bentonite, illite, and kaolinite were also treated with enzymes to study the effect on their strength characteristics. Soil samples prepared at the optimum moisture content (OMC) were sealed and cured for four months. After curing, reference clays were tested for unconfined compressive strength (UCS). For swell tests, the S1 soil samples were placed on porous stones, which were immersed in water to allow capillary soaking of the samples. S1 samples were allowed to dry at ambient temperature for shrinkage test until the rate of reduction in volume became negligible. On completion of swell tests, the samples were tested for UCS to determine the decrease in strength due to saturation. No increase in strength and decrease in volume change were observed for any of the enzymes and dosages. Field Emission Scanning Electron Microscope (FESEM) showed some dense packing of particles for treated samples, whereas X-ray diffraction (XRD) did not reveal any change; in fact, the pattern for untreated and treated soil samples were indistinguishable.

Low bearing capacity soils may pose serious construction concerns such as reduced bearing capacity and excessive hydro-associated volume changes. Proper soil remediation techniques must be planned and implemented before commencing any construction on low bearing capacity soils. Environmentally friendly soil stabilizers are gradually replacing traditional soil stabilizers with high carbon dioxide emissions such as lime and cement. This study investigated the use of an alternative pozzolanic mix of nano-additives (i.e., nano-silica and nano-alumina) and cement to reduce the usage of cement for achieving competent soil stabilization outcomes. A series of unconfined compressive strength (UCS), direct shear, and durability tests were conducted on marl specimens cured for 1, 7, and 28 days stabilized with nano-additives (0.1~1.5%), 3% cement, and combined 3% cement and nano-additives. The UCS and shear strength of stabilized marl increased with nano-additives up to a threshold nano-additive content of 1% which was further intensified with curing time. Nano-additive treated cemented marl specimens showed long durability under the water, while the cemented marl decomposed early. The microfabric inspection of stabilized marl specimens showed significant growth of calcium silicate hydrate (CSH) products within the micro fabric of nano-silica treated marl with reduced pore-spaces within aggregated particles. The results confirmed that nano-additives can replace cement partially to achieve multi-fold improvement in the strength characteristics of the marl.

Casein is often used as an eco-friendly wood adhesive. In this study, we used casein for soil cementation by mixing it with Jumunjin sand, sodium hydroxide (SH), and calcium hydroxide (CH) as a standard casein formula. The modified casein binder with different proportions of SH and CH was applied to improve water resistance. Furthermore, a blast furnace slag (BFS) was additionally mixed and reacted with alkalinity of modified casein binder. Thus, three types (standard, modified, and modified + BFS, referred to as STD, MOD, and MBS, hereafter) of casein binders were tested for durability and strength of casein-cemented sand. A piezoelectric sensor was installed within each sample to determine the curing time of the casein-cemented samples. The samples were air-cured at room temperature for seven days and some were repeatedly immersed in water thrice. Unconfined compression and jar slake tests were carried out to evaluate the strength and durability of the casein-cemented sand. Also, the microstructure was analyzed using a scanning electron microscope (SEM). We observed variations of peak conductance and corresponding frequency converged as the curing time increased. It was most significant for the MBS samples, which developed strength early. The unconfined compressive strength (UCS) of the air-cured samples was higher than those repeatedly immersed in water due to wash-off of the casein binder. The UCS of the dry MBS sample was 9900 kPa while that of the immersed sample was 430 kPa, which gradually decreased to 60 kPa upon repeated immersion. The samples with STD and MOD had no resistance to durability and showed cracks on the surface, while the MBS sample exhibited significantly improved durability and no cracks. We found that the MBS binder had a positively significant effect on the durability and strength of casein-cemented sand.

In this research, the time-dependent changes induced in charge characteristics of phosphoric acid and lime treated quartz-rich kaolinitic soil were investigated. Also, in order to study the relationship between the exchange capacity and the pore water chemistry, pH measurements was performed on cured samples. Based on the collected data, it was found that the pH of stabilized soils showed a tendency for reaching soil’s natural pH with increasing curing time. In addition, the increase in number of broken bonds around the edges of soil particles and also the formation of cementitious compounds that acquired negative charges contributed to achieving higher CECpvalues at longer curing periods. From engineering point of view, the lime treated samples revealed the highest degree of improvement with an approximately 16-fold strength increase in comparison to the natural soil over an 8 months curing period.

AbstractCyclospora cayetanensis, a coccidian parasite that causes protracted and relapsing gastroenteritis, has a short recorded history. At least 54 countries have documented C. cayetanensis infections and 13 of them have recorded cyclosporiasis outbreaks. Cyclospora cayetanensis infections are commonly reported in developing countries with low-socioeconomic levels or in endemic areas, although large outbreaks have also been documented in developed countries. The overall C. cayetanensis prevalence in humans worldwide is 3.55%. Among susceptible populations, the highest prevalence has been documented in immunocompetent individuals with diarrhea. Infections are markedly seasonal, occurring in the rainy season or summer. Cyclospora cayetanensis or Cyclospora-like organisms have also been detected in food, water, soil and some other animals. Detection methods based on oocyst morphology, staining and molecular testing have been developed. Treatment with trimethoprim–sulfamethoxazole (TMP–SMX) effectively cures C. cayetanensis infection, whereas ciprofloxacin is less effective than TMP–SMX, but is suitable for patients who cannot tolerate co-trimoxazole. Here, we review the biological characteristics, clinical features, epidemiology, detection methods and treatment of C. cayetanensis in humans, and assess some risk factors for infection with this pathogen.

In this study, effects of metakaolin and lime on the microstructural characteristics, unconfined compressive strength (UCS), shrinkage, suction, and shear resistance of laterite were investigated. Soil samples treated with 5 wt% of lime (LaL) or 4 wt% metakaolin and 5 wt% of lime (LaLM) were prepared. Samples with an optimal water content of 32% were compacted and cured for 180 days, followed by saturation and dehydration until the desirable water content of the samples was attained. Then, the UCS, shrinkage, and suction and shear resistance of the samples at a normal stress of 200 kPa were determined. In addition, scanning electron microscopy imaging as well as mercury intrusion porosimetry tests were performed to examine the microstructural changes. Results indicate that the shrinkage of treated soil samples is significantly improved in comparison with that of the untreated soil samples. Lime effectively improves the UCS and shearing resistance of laterite. Moreover, metakaolin is composed of amorphous silicon and aluminium oxides and shared edge-face structures on the microscopic scale; hence, it can considerably capture calcium ions from a lime solution, generating cementitious hydrates in the interaggregates of laterite. Results also revealed that the combination of 5 wt% of lime and 4 wt% of metakaolin can improve the UCS and shearing resistance, but the linear shrinkage is particularly restrained, significantly decreasing by 4 times compared with that of the lime-treated soil sample and by 8 times compared with that of the untreated soil sample. The study results demonstrate that metakaolin and lime can be effectively used to improve laterite in lieu of the conventional lime treatment for mitigating geotechnical engineering disasters.

Using sewage sludge as temporary cover for landfills is one of the most effective methods to dispose sludge. The mechanical properties of solidified sludge usually meet the requirements for temporary landfill cover, but its low permeability can cause problems due to formation of perched leachate. This study focused on the effect of solidification and remolding on hydraulic conductivity of sludge and conducted permeability tests on sludge solidified by using either ordinary Portland cement (OPC) or sulphoaluminate cement (SAC). The related pore structure and aggregate size distribution were analyzed later by the mercury intrusion pressure (MIP) method and soil water characteristic cure (SWCC) method. The experiment results show that the hydraulic conductivity of solidified sludge was in the range of 10−7∼10−6 cm/s. When sludge is solidified with an SAC dosage >40% and remolded after curing for 7 days, its hydraulic conductivity increases sufficiently to the order of 10−4 cm/s. The trend for solidified sludge exhibited a power function relation between the logarithmic hydraulic conductivity and the proportion of macropores. Overall, it can be concluded that the increase of hydraulic conductivity is attributed to the development of an aggregate structure, with water being transmitted mainly through the interaggregate pores; therefore, the sludge could be used as temporary landfill cover.

Rapid settlement assessment in new reclaimed land is important to follow-up engineering construction. Vacuum-surcharge preloading combined with prefabricated vertical drains (PVDs) is a high-efficient and widely used reclaimed soil-reinforced method. This work focuses on micro-macro mechanism of vacuum and surcharge preloading, and the settlement characteristics of subsoil subjected to vacuum-surcharge pressure are discussed. The surcharge preloading is applied to soil particles directly by vertical stress, and the effective stress increases directly by direct contact among particles. However, vacuum pressure increases the effective stress and decreases the pore pressure at the same time. In new reclaimed land, the proposed method is working on the assumption that the new reclaimed land full of water with particles arranging in a loose state of simple cube (SC) way before treatment, while a dense state of terse tetrahedron (TH) way, a stable structure of soil, after treatment. An approach for calculating the final settlement of new reclamation land is derived in two-dimensional (2D) and three-dimensional (3D) perspective, respectively. Meanwhile, this method has been preliminarily applied to two case histories reported in the literature. Results show that 2D estimation method might be more useful for the preliminary assessment of settlement under a combined vacuum and surcharge preloading in new reclaimed land.

Geologic carbon sequestration (GCS) has been pursued as a feasible strategy to store the large amount of CO2 to curb its emission to the atmosphere in an effort to mitigate the greenhouse effects. CO2 hydrate, which can form when the pressure and temperature satisfy its stability condition, can provide a self-trapping mechanism for an offshore CO2 geologic storage. For example, direct sequestration of CO2 in the form of hydrate crystals can be achieved in the storage aquifer under the seafloor. Besides, the formation of CO2 hydrates in an upper layer of the CO2 storage zone can potentially provide a secondary caprock. These applications, however, require a thorough understanding of the formation and dissociation of CO2 hydrates in porous media, which are largely unknown yet. In this manuscript, a laboratory study on the formation and dissociation of CO2 hydrates in two different environments, a two- (CO2-water) or three-phase (CO2-water in glass beads) condition, is presented. Based on the experimental results, it can be anticipated that the pressure and temperature change will be negligible when the formation of CO2 hydrate is induced for GCS in the actual soil/rock layers. Besides, the formation of CO2 hydrate in porous media may be faster, compared to the two-phase bulk condition that has been typically used in many laboratory studies, as solid grains help accelerate the hydrate formation by providing nucleus sites of crystals. Further elaborations on the role of solid grains would bring a clear path for the feasible application in the subsea area.

Fractures are developed in carbonate rock areas, and the fracture water flow significantly influences the heat exchange between buried pipes and the rock mass by induing heat convection, providing the carbonate rock area a strong heat exchange capacity and preferable conditions for shallow geothermal development and utilization. In this paper, the calculation method of heat exchange capacity of buried pipes based on fracture distribution characteristics is proposed and deduced, featuring such advantages as quick speed and low cost. Taking an actual project in carbonate rock area as an example, the heat exchange capacity of buried pipes was obtained by the following two methods: in-situ thermal response test and calculation based on fracture distribution characteristics. In the thermal response test, the initial ground temperatures of the two test holes were 15.18 °C and 12.72 °C. By fitting the linear equation of time and average temperature with a linear thermal source model, the heat exchange capacities were 57.21 W/m and 58.22 W/m, the thermal conductivities were 3.56 W/(m·K) and 2.32 W/(m·K), the thermal diffusivities were 1.71 × 10−6 m2/s and 1.12 × 10−6 m2/s, and the volume specific heat capacity was 2.08 × 106 J (m3·K). The test results indicated that the thermal property parameters of rock and soil mass were higher than those of other areas, with obvious wide-range distribution characteristics. Through the statistical analysis of outcrop fracture characteristics, combined with the cube law to calculate the fracture water flow and convective heat transfer, an alternative method for the calculation and optimization of buried pipe heat transfer in fractured rock mass area is also proposed in this paper. According to the measured fracture distribution characteristics of the field outcrop, the heat exchange capacities of the two holes were 57.26 W/m and 58.56 W/m, which were basically consistent with the thermal response test values and verified the reliability of the calculation method of heat exchange capacity of buried pipes based on fracture distribution characteristics.

In order to effectively utilize aluminum industrial waste—red mud and bauxite tailings mud—and reduce the adverse impact of waste on the environment and occupation of land resources, a red mud–bauxite tailings mud foam lightweight soil was developed based on the existing research results. Experiments were conducted to investigate the mechanical properties and microscopic characteristics of the developed materials with different proportions of red mud and bauxite tailings mud. Results show that with the increase in red mud content, the wet density and fluidity of the synthetic sample was increased. With 16% red mud content, the water stability coefficient of the synthetic sample reached its maximum of 0.826, as well as the unconfined compressive strength (UCS) of the sample cured for 28 d (1.056 MPa). SEM images reveal that some wastes of the sample without red mud were agglomerated, the peripheral hydration products were less wrapped, and when the amount of red mud was 16%, the hydration products tightly wrapped the waste particles and increased the structural compactness. The final concentration of alkali leaching of samples increased with the addition of red mud. The maximum concentration of alkali leaching was 384 mg/L for the group with the addition of red mud of 16%. Based on the obtained mechanical strength and alkali release analysis, the sample B24R16 was selected as the optimum among all tested groups. This study explored a way to reuse aluminum industrial waste, and the results are expected to be applied to roadbed and mining filling.

АBSTRACT Introduction. For solving environment protection problems and reducing the volume of ‘polymer waste’, the study of biodegradability of polymer materials by means of their modification without impairing main performance is of practical importance. This is achievable by application of biodegradable natural additives. The radical solution is the development of polymer materials that are capable of retaining their performance throughout their service life only. Materials and methods. To modify compositions, APh-2 aminoalkylphenol-cured ED-20 epoxy diane resin was used. Liquid fraction of rubber tree oil (RTO) and Vietnam-produced soybean oil (SO) were used as the modifiers. Biodegradability of the materials was evaluated by Sturm’s method checking respirometric activity of soil in their presence. Resistance of the epoxy materials to microbiological putrefaction in soil was investigated by mass loss value. Thermal stability of the epoxy coatings was tested by simultaneous thermal analysis on Netzch-Gerätebau GmbH apparatus at the heating rate 10 °C/min when the temperature varying within the range of 25 °C to 600 °C. Water absorption was evaluated as per GOST 4650-2014 standard. Sol-gel analysis was implemented in boiling acetone in the Soxhlet apparatus. Abrasion hardness of epoxy materials was carried out on the IZV-1 vertical optical caliper. Hardness was checked by Barcol impressor. Frictional factor was determined by means of the CSM Instruments Tribometer automated friction machine. Results. Applying vegetable oils governs a significant growth of the abrasion resistance and enhancement of antifriction characteristics of epoxy materials. The vegetable oils exercise a plasticizing effect on epoxy compositions, accelerate processes of epoxy material biodegradation in soil and reduce their resistance to micromyces. Epoxy resin is characterized with high funginertness and its modification by the RTO results in enhancement of biodegradability when exposed to mouldy fungi. Conclusions. Applying the RTO as a modifier of the epoxy materials accelerates processes of their biodegradation in soil and decreases their resistance to micromyces. The higher biodegradation of vegetable oil-modified epoxy films takes place at complex exposure to bacteria and mycelian fungi as a part of soil microbiocenosis.

Freeze-thaw (FT) cycles and moisture susceptibility are important factors influencing the geotechnical characteristics of soil-aggregates. Given the lack of published information on the behavior of cement-bitumen emulsion-treated base (CBETB) under environmental conditions, especially freezing and thawing, this study investigated the effects of these additives on the CBETB performance. The primary goal was to evaluate the resistance of CBETB to moisture damage by performing FT, Marshall conditioning, and AASHTO T-283 tests and to evaluate the long-term stripping susceptibility of CBETB while also predicting the liquid antistripping additives to assess the mixture’s durability and workability. Specimens were stabilized with Portland cement (0%–6%), bitumen emulsion (0%–5%), and Portland cement-bitumen emulsion mixtures and cured for 7 days, and their short- and long-term performances were studied. Evaluation results of both the Marshall stability ratio and the tensile strength ratio show that the additions of additives increase the resistance of the mixtures to moisture damage. Results of durability tests performed for determining the resistance of compacted specimens to repeated FT cycles indicate that the specimen with the 4% cement-3% bitumen emulsion mixture significantly improves water absorption, volume changes, and weight losses. This indicates the effectiveness of this additive as a road base stabilizer with excellent engineering properties for cold regions.

Background: Melioidosis is caused by Burkholderia pseudomallei, a gram negative non-fermentative bacillus found in water and soil. Transmission to human is by contact and it causes disease mostly in the immunocompromised state. As melioidosis closely mimics tuberculosis it is often misdiagnosed and often empirically treated as tuberculosis. Increasing numbers of published cases among Bangladeshis and isolation of B. pseudomallei in the soil of Gazipur district has confirmed our country as a ‘definite country for melioidosis’.Methods: This study was carried out in the Department of Medicine, Bangladesh Institute of Research and Rehabilitation in Diabetes, Endocrine and Metabolic Disorders (BIRDEM) General Hospital, Dhaka, Bangladesh from September 2013 to September 2016. Adult patients with melioidosis confirmed by growth of B. pseudomallei from different specimens were included. Socio-demographic, clinical and laboratory characteristics were studied and treatment outcome was also documented.Results: Total 11 cases including 9 males were detected with melioidosis during the study period. All cases were diabetic. Mean age was 39.73 years. Eight cases were classified as endemic while 3 patients returned from overseas. Four patients’ (36.36%) home district was Tangail. Common presentations were fever (100%), cough (45.45%), dysuria (36.36%), cutaneous lesions (36.36 %) and septic shock (36.36%). The common sites involved were skin (36.36%), genitourinary tract (36.36%) and lung (36.36%) followed by joint (18.18%). Ten cases (90.9%) had neutrophilic leucocytosis with raised ESR/CRP in all cases. Culture of sixteen different specimens revealed growth of B. pseudomallei. In 6 a cases co-trimoxazole resistance was found in vitro. Common radiological findings showed lung involvement (36.36%) and organ abscess (18.18%). One patient was lost from follow up following discharge. Among the remaining 10 patients, 6 were declared cured, 1 patient improved and 3 patients died from septic shock. Ceftazidime/meropenem as initial therapy followed by a combination of doxycycline and trimethoprim-sulfamethoxazole or doxycycline and amoxicillin-clavulanic acid proved to be effective.Conclusion: Observation revealed that this disease, if remained untreated, can cause life threatening complications, even death. Therefore, suspicion of melioidosis should be considered in appropriate clinical scenario.Birdem Med J 2017; 7(1): 28-37

AbstractThe present study reviews previous published estimates as to the scale of food waste in the USA and its ecological toll (e.g., in terms of methane emissions and water usage to support the production of wasted food). The review further discusses recent public policy and private action designed to curb food waste or to apply wasted food toward hunger alleviation, biofuel production and soil nourishment. We further consider and expand upon previous estimates comparing the scale of food waste to the present scale of the US hunger problem. These estimates suggest that the recovery and redirection of an additional 15% of the present stock ofediblefood waste would meet 35% of the caloric needs of all Americans living in a food insecure household or very low food security household. Then, a modest to moderate proportional increase in edible food waste recovery could greatly reduce the US hunger problem in its present state. We estimate that the successful redirection of 15% of presently-wasted (edible) food in the USA would be sufficient to fully sustain 18.45 million individuals. Given available data, we cannot precisely assess the nutritional characteristics of this potential stock of food. The present study emphasizes the traditional and future importance of integrated public policy and private action at the municipal level, as food waste is typically disposed of or recovered at this level.

The maturity of fresh tobacco leaves affects the browning of leaves to differing degrees during the curing process, thus affecting the quality of cured tobacco leaves. In this study, tobacco leaves of increasing maturity (M1–M4) were selected. Dark-box experiments were performed to investigate the roasting characteristics and relationship between tobacco leaf maturity and browning and to determine their polyphenol oxidase (PPO) activities and qualities. We found that mature tobacco leaves (M3) had high substance accumulation, and the PPO activity decreased throughout the baking process. After 72 h of curing, the PPO activity in the M3 leaves was 81.22 U/g, which was significantly different from that in M1 and M2. On this basis, three different browning inhibitors (control: 10 mL of distilled water; T1:10 mL of 0.5% citric acid+0.5% polyphenol; and T2:10 mL 0.5% citric acid+0.5% salicylic acid) were sprayed onto the surface of M2 leaves before curing to observe their inhibitory effects. The T2-treated leaves showed inhibited PPO activity, and after baking for 72 h, the peroxidase enzyme (POD) content of the T2-treated leaves was higher, which effectively inhibited the enzymatic reaction. In conclusion, to reduce the browning ratio of tobacco leaves during the curing process, the harvested tobacco leaves should be allowed to reach full maturity when the values of Soil Plant Analysis Development (SPAD) chlorophyll meter ranged 9–13, and 0.5% citric acid+0.5% salicylic acid (T2) should be used as a browning inhibitor to produce tobacco with the highest sensory quality. The results of this study can help inhibit browning and maintaining the quality of the tobacco leaves during the curing process.

Цель исследования – оценить видовой состав грибов рода Fusarium, развивающихся по фитофторозу, а также уточнить источники и локализацию фузариоза в клубнях картофеля с учетом подобной сукцессии и фитосанитарной ситуации. Исследования проводили в лаборатории сектора фитопатологии кафедры защиты растений РГАУ – МСХА имени К.А. Тимирязева в 2021–2023 годах. Отобранные клубни сортов картофеля Ред Скарлетт и Адретта отмывали от почвы в водопроводной воде. Поверхностную стерилизацию проводили по соответствующей методике. Для этого клубни погружали в 2%-ный раствор гипохлорида натрия на пять минут, трижды промывали стерильной дистиллированной водой и высушивали стерильной фильтровальной бумагой. Из стерилизованных клубней извлекали их центральную часть и нарезали на кубики площадью 1 см2. Далее, исходя их варианта опыта, на кубик помещали фрагменты сосудистого кольца, глазков и перидермы. На образцы наносили 80 мкл суспензии изолята P. infestans 161, из коллекции РГАУ – МСХА имени К.А. Тимирязева (любезно предоставлен ВНИИКХ имени А.Г. Лорха в 2014 году) и инкубировали во влажной камере при температуре 20–23 °C и умеренном освещении в течение 10 суток. Варианты опыта включали в себя: 1) стерильный кубик и перидерму; 2) стерильный кубик и глазки; 3) стерильный кубик и сосудистое кольцо; 4) отрицательный контроль в виде стерильного кубика. Фитофтора создает точки проникновения возбудителей фузариоза в клубнях картофеля. Локализация грибов рода Fusarium в исследованных клубнях после их поражения фитофторозом связана с перидермой клубней картофеля. Виды рода Fusariumбыли идентифицированы с помощью сочетания морфологических, культуральных (строение колоний, мицелиев и конидий) и молекулярных (ПЦР и секвенирование) характеристик. Молекулярной идентификацией выявленных грибов рода Fusarium установлен комплекс трех видов: F. oxysporum, F. Proliferatum и F. solani. Этот факт необходимо учитывать при производстве и хранении продовольственного и семенного картофеля. The aim of the study is to evaluate the species composition of Fusarium fungi developing due to late blight, as well as to clarify the sources and localization of Fusariumin potato tubers, taking into account such succession and phytosanitary situation. The research was carried out in the laboratory of the Phytopathology sector of the Department of Plant Protection of the Russian State Agricultural Academy named after K. A. Timiryazev in 2021–2023. The selected tubers of the Red Scarlet and Adretta potato varieties were washed from the soil in tap water. Surface sterilization was carried out according to the appropriate method. To do this, the tubers were immersed in a 2% solution of sodium hypochloride for five minutes, washed three times with sterile distilled water and dried with sterile filter paper. The central part of the sterilized tubers was extracted and cut into cubes with an area of 1 cm2. Further, based on their version of the experiment, fragments of the vascular ring, eyes and periderm were placed on the cube. 80 µl of P. infestans 161 isolate suspension was applied to the samples, from the collection of the Russian State Agricultural Academy named after K.A. Timiryazev (courtesy of the Russian Potato Research Centre in 2014) and incubated in a humid chamber at a temperature of 20–23 °C and moderate lighting for 10 days. Experience options included: 1) sterile cube and periderm, 2) sterile cube and eyes, 3) sterile cube and vascular ring, 4) negative control in the form of a sterile cube. Phytophthora creates penetration points of Fusarium pathogens in potato tubers. Localization of Fusarium fungi in the studied tubers after their defeat by late blight is associated with the periderm of potato tubers. Fusarium species were identified using a combination of morphological, cultural (colony structure, mycelia and conidia) and molecular (PCR and sequencing) characteristics. Molecular identification of the identified fungi of the genus Fusarium revealed a complex of three species: F. oxysporum, F. Proliferatum and F. solani. This fact must be taken into account when producing and storing food and seed potatoes.

Fire trucks should be maximally adapted to the elimination of emergency situations, in particular, to provide the necessary intensity of supply of extinguishing agents, that is, to be multifunctional. Special requirements are imposed on fire-fighting vehicles: high cross-country ability and speed, the ability to transport one compartment, transport tools and equipment for grabbing, backfilling with soil, filling the edge of the fire with water or chemical solutions, and the like. Scientific research is aimed at developing ways to assess the effectiveness of new models of fire and rescue vehicles for compliance with the requirements of the Ministry of Emergency Situations of Ukraine, in particular, through comparative analysis with alternative samples, to determine the factors affecting the operation of a fire truck, to develop a method for adapting vehicles for emergency response, to improve their level of operational excellence and operational efficiency. To realize the purpose of the assessment tests, a test procedure was developed and an experimental model of a fire-fighting vehicle for emergency response was created. The obtained relationship between the number of revolutions of the crankshaft of the engine and the value of the dynamic torque in the transmission of the test fire vehicle in the case of a sharp engagement of the clutch in the vehicle starting modes can be represented graphically. It is proposed to compare different variants of fire engine designs to take this characteristic as an efficiency criterion. Experimental studies were carried out: starting a car from a place on a steep rise, followed by an increase in gears; overcoming a roadside ditch with flat walls 0.2–0.6 m deep and at an angle of 45° to its axis; running over with wheels of one side of a fire engine on a curb 140–150 mm high; entering a turn from straight-line movement to the minimum possible turning radius on an asphalt surface in II and III gears at a constant speed of 10-12 km/h. To confirm the validity of the accepted assumptions of the mathematical model, the accuracy of applications and the reliability of the results obtained, the adequacy of mathematical modeling was checked by comparing the test problems of statics and dynamics of the movement of fire trucks for emergency response. A fire truck for liquidation of emergency situations, modeled on the basis of the proposed adaptation method of the base chassis for the needs of extinguishing forest fires and the formation of a container module, makes it possible to increase the efficiency of its use according to the selected criteria by 18%. The use of the longitudinal flexibility of the container modules in comparison with the conventional body mount provides a reduction in fuel consumption when driving a fire truck up to 4%.

The quantity of municipal solid waste (MSW) generation is escalating at an alarming rate with every passing year alongside the modernization of our economy. Unfortunately, the majority of this waste remains uncollected or ends up in open dumping and followed by uncontrolled burning. Citing the deep-rooted consequences, open dumping should be absolutely abandoned and scientific interventions should be aggressively exercised to reclaim the municipal brownfields. The present research work undertook the judicial task of assessing the comparative feasibility of biomining and scientific capping as a technology selection for reclamation of about a decade old 120 million tons of waste chunk laying at Jawahar Nagar dump yard. Primary dump samples were collected from various locations, considering depth as a variable. While leachate and groundwater samples were collected from Malkaram lake and preinstalled borewells receptively. Additionally, the ambient air quality and noise level also been ascertained within the buffer zone. The blended representative solid sample was segregated using a 70 mm mesh size trommel into organic and inorganic fractions. The organic fraction was composted using a lab-scale aerobic static pile composting (ASPC) while the trommel reject was processed as refuse derived fuel (RDF). Evidently, the compost lagged quality and depicted nutrient deficiency. While the burning of RDF produced siloxane gas, significantly due to elevated silicon level in the primary waste. Furthermore, due to the prolonged leaching tenure and seasonal dilution, the concentration of legacy leachate was relatively weaker. Borewell samples collected from a depth of 20 feet also portrayed minor contamination up to 500 meters horizontal radius. The issue of leachability can solely be resolved with the capping of the existing dump and the end product quality derived from the biomining process is highly questionable. Thus, handling such large quantity capping is a befitting option over biomining for Jawahar Nagar dumpsite. INTRODUCTION Presently, in India due to rapid urbanization and industrialization, the generation of MSW has been increasing tremendously and also expected to continue a similar trend in the future (Scott, 1995; Bhat et al., 2017; Sethurajan et al., 2018; Sharma et al., 2018). Annually, the comprehensive urban MSW generation in India is more than 62 million tons. Metro cities are the mammoth contributor of the entire chunk and waste production had already reached an alarming figure of 50,000 tonnes/day. While the waste generation from the tier 2 cities is also rigorously escalating and presently contribute up to 20,000 tones/day (Sharma et al., 2018). A study conducted by the central pollution control board (CPCB) revealed MSW generation in India is increasing at a distressing rate of 5 % per annum with a sharp escalation in the quantities of domestic hazardous waste (Sharma et al., 2018). With major financial constraints, inefficacy of collection, treatment, and disposal incurs further reasons to worry. So far India has miserably failed to set up wholesome source segregation and collection method. Presently, the country spends more than 60% of its annual waste management budget only in collection. Besides, only 20% or less of the collected materials are scientifically handled and treated. Citing the statistics, it is evident that the majority of the MSW is simply gets dumped on the low laying grounds located somewhere on the outskirts of the cities. The precipitation, infiltration, surface water runoff, bird menace, rodent interference etc. triggers the vulnerability of waste and leads to mal odor, ground and surface water contamination, human and environmental health deterioration (Jayawardhana et al., 2016). Further, the perseverance of the inorganic and inert fractions leads to soil contamination, poses a fire threat, and also may incur carcinogenicity and acute toxicity among the animals (Mir et al., 2021). There are numerous techniques for the reclamation and remediation of the dumpsites, includes processes such as capping and closure, in-situ vitrification, sub-surface cut-off walls, and waste biomining (Chakrabarti and Dubey, 2015; Thakare and Nandi, 2016). Waste biomining is a stable way to get rid of the entire range of problems associated with open dumping and reclaim valuable land (Kaksonen et al., 2017). There are several instances including reclamation of Mumbai Gorai dump yard by IL & FS Environment, 70 – 80 years old 12,00,000 tons of dump clearance by Nagar Nigam Indore within a minute span of 3 years and many more. But the process of biomining is highly sensitive and case-specific. The success of the process solely depends on factors such as characteristics of the waste, efficacy of the effective microorganism culture, acceptability of the processed end product at the local market etc. (Jerez, 2017; Banerjee et al., 2017; Venkiteela, 2020). Contrarily, though the scientific capping is not an end-to-end solution but still advisable in the cases where the quantity of waste is gigantic, land scarcity is prevalent, no nearby industries to consume the end products etc. Mehta et al. (2018) have also supported the above claim based on the assessment of locations specific MSW dump reclamation case studies. While in another Nagpur-based case study conducted by Ashootosh et al. (2020) reported the superiority of the biominingprocess over simple land capping due to the favorability of the local conditions. Capping eliminates the environmental interference and thereby reduces biosphere contamination and leachate generation. Further, it captivates rodent and vector breeding and thereby curtails the spreading of communicable diseases and improves aesthetics. But right consolidation through compaction and execution is utmost necessary in the above case. As non-compaction and faulty sloping will easily lead to heavy settlement and slope failure (Berkun et al., 2005; Al-Ghouti et al., 2021). The present study has been pursued with the primary objective to run a techno-commercial assessment between scientific capping and biomining. While the secondary objective was to ascertain the level of contamination and propose mitigative measures. MATERIALS AND METHODStudy Area Spanning over 350 acres of a precious piece of land at the outskirts of Hyderabad city, Jawahar Nagar dumping yard was brutally utilized by the Greater Hyderabad Municipal Corporation (GHMC) for open dumping for a prolonged tenure of 10 years. It housed nearly 12 lakh metric tons of heterogeneous solid and domestic hazardous waste and continues polluting until 2015, until the Ramky group was offered to cap the legacy dumping and scientifically handle the site. The present study has been facilitated at Hyderabad Municipal Solid Waste Limited, formerly known as Jawahar Nagar dump yard to analyze and assess the feasibility of bio-mining as handling and management alternate to the existing practice of scientific capping. The epicenter of processing and disposal facility is lying approximately on the cross-section of 17°31'24.45"N and 78°35'23.37"E. As per the contract, the comprehensive legacy dumping to be capped in three phases over about 150 acres of area and Ramky has significantly entered the phase two of the operation only within a span of five years by successfully capping more than half of the legacy footprint. Sampling Methodology The waste pile was divided into three layers namely, base, middle, and top. A uniform amount of sample was collected from the successive layers of all five different corners which cover north, south, east, west, and central of the garbage pile. Sampling inspections were performed using a manual auger besides large samples were collected using a JCB excavator. The top six-inch layer of the pile was removed to avoid any contamination while collecting the samples and 5-10 kg of sample was collected from each of the locations. Further, intermediate and bottom layer samples were collected by digging a 500 mm diameter hole through the heap. A composite was prepared by a homogenized blending of all the fifteen grub samples. The blend was distributed into four equal quadrants and the top and bottom quadrants were eliminated diagonally while the left-over quadrants were mixed thoroughly. This process was repeated until a sample of the required bulk of 20 kg is obtained. Surface and subsurface water samples from borewell were collected in and around the facility. Piezometric monitoring borewells located near the landfills were utilized for the subsurface sample collection. While a rainwater pond turned leachate lake named Malkaram was determined as the primary source for leachate collection. Buffer samples were collected from Ambedkar Nagar, the nearby colony exiting at a distance of only 300 meters. Lab-scale Experimentation The representative sample was characterized for composition and further screened through a 70 mm mesh size trommel. The trommel permeate was considered as the organic fraction while the reject was mostly inorganics and inert. The organics were subjected to ASPC. The quantity of the air required is arrived using the method delineated below (Figure 1). MSW Pile size: 2m x 0.5m x 0.5m Volume of pile: 0.5 m3 Average Density of MSW: 620 Kg/m3 Weight of pile: 310 Kg Nitrogen required for matured compost: 9300 mg/kg dry : 9300 X 310 mg : 2.88 x 106 mg : 2.88 Kg Total air required: 2.88 x 100/76 [as Nitrogen in air is 76% by weight] : 3.79 Kg of dry air : 3.79/1.225 m3 [@ 15 deg C density of air 1.225 kg/m3] : 3.1 m3 This air is to be supplied for 100 min / day for 0.5 m pile Air flow rate required: 3.1 x 60/100 = 1.86 m3/h (for practical purpose a flowrate of 2 m3/h was maintained). The maturation period was considered as 28 days and post-maturation, the stabilized material was further cured for 24 hours and screened using 12 mm and 4 mm trommel respectively to obtain the desired product quality and particle size. Whereas, the trommel reject was evenly spreader on the copper trays and dried in an oven at 1050C for 2 hours. The dried material was micronized to the size of 50 mm or below using a scissor and inert such as glass, sand, stone etc. were segregated manually (Mohan and Joseph, 2020). Concurrently, a bench-scale capped landfill prototype was built using the below-mentioned procedure to evaluate the factors such as settlement and slope stability. A 30 mm thick low permeable soil was laid on the top of the waste, followed by a 60 mm layer of compacted clay liner (CCL). Each join between successive liner material was closely monitored. A 1.5 mm thick HDPE liner was placed on the top of the CCL. A 285 GSM geotextile membrane was placed as the successive above layer followed by a 15 mm thick drainage media layer. A further layer of geotextile membrane was placed on top of the drainage media for better stabilization, grip, and strength. The top vegetative soil layer of 45 mm thickness was laid off on top of the geotextile media and St. Augustine grass was rooted (Cortellazzo et al., 2020; Ashford et al., 2000). 2.4 Sample Analysis pH, Electrical Conductivity (EC) and Turbidity of the samples were analyzed using pH, EC-TDS, and Nephelometer of Mettler Toledo. The pH meter was calibrated with the buffer solution of 4.0, 7.0 & 9.12 at a controlled temperature. EC-TDS meter was calibrated with 0.1 M KCL having 12.8 mS/cm of conductivity. Nephelometer was calibrated with Formazine solution of 10 & 100 NTU. Total Dissolved Solids (TDS), (mg/L) was performed using the gravimetric method at 1800C in the oven. Titrimetric parameters such as Total Alkalinity as CaCO3 (mg/L), Total Hardness as CaCO3 (mg/L), Chloride as Cl- (mg/L), Calcium as Ca2+ (mg/L), Residual Free Chlorine (RFC), (mg/L) were analyzed using APHA (American Public Health Associations) method, 23rd Edition, 2017. Total Kjeldahl Nitrogen (mg/L) and Ammonical Nitrogen (mg/L) were performed through distillation followed by titration with H2SO4 as a titrant. Sulphide as S2- was done with the Iodometric method after distillation. Each titrimetric parameter was analyzed in triplicate after standardizing the titrant with required reagents and crossed checked by keeping a check standard. Sodium as Na (mg/L) and Potassium as K (mg/L) were performed using Flame Photometer. The photometer was calibrated with different standards from 10 to 100 (mg/L) standard solutions. The leachate sample was diluted enough to get the value within the standard range and cross-checked with check standards at the same time. Chemical Oxygen Demand (COD), (mg/L) was performed using the open reflux method for 2 hours at 1500C in COD Digestor. Biochemical Oxygen Demand (BOD), (mg/L) was performed using the alkali iodide azide method for 3 days. The samples were kept in a BOD incubator at 270C for 3 days. It was kept in duplicate to have a check on quality control. Sulphate was analyzed by the gravimetric method instead of turbidimetric or through UV-Visible spectrophotometer as its concentration was found more than 40 mg/L. Nitrate as NO3- was analyzed after filtration at 220-275 nm, while Hexavalent Chromium as Cr6+ was analyzed at 540 nm in the UV-Vis. Parameters like Cyanide as CN-, Fluoride as F-, and Phenolic Compounds were gone through a distillation process followed by UV-Vis. The distillation process ensures the removal of interferences presents either positive or negative. For the parameters like Total Iron or Ferric Iron, the samples were digested properly with the required reagents on the hot plate before analyzing in UV-Vis. For the metal analysis the water samples were digested at a temperature of 1000C using aqua regia as a media. The samples were digested to one-fourth of the volume on a hot plate. The recommended wavelengths as per APHA 3120 B were selected for each of the metals. The standard graph was plotted for each of the metals before analysis and crossed checked with the check standard at the same time. Parameters such as bulk density and particle size were performed through the certified beaker and sieve. The percentage of moisture content was estimated using the oven by keeping the compost sample for 2 hours at 1050C. C/N ratio was estimated through CHNS analyzer keeping sulfanilamide as a check standard. The analysis was performed by extracting the desired component in the desired solution prescribed in the method followed by converting the same from mg/L to mg/Kg. RESULTS AND DISCUSSION An exhaustive bench-study has been pursued and real-time samples were collected and analyzed for all possible parameters to determine the pros and cons attributed to both processes. The investigation begins by collecting the samples and concluded by impact assessment studies inclusive of the buffer zone. Both solid, liquid, and gaseous samples were precisely investigated to opt for the best solution. A detailed finding of the investigation is summarized below. Primarily, the representative solid sample was characterized through a manual separation process and the results are portrayed in Figure 1. Compost Characterization ASPC of the organic fraction has resulted in a recovery of 46.7% of the initial load. While 53.3% of the influent mass were inert and barely degradable fraction contributes to reject, the rest 4.1% is miscellaneous process loss. The processed compost was extensively analyzed including for metal contamination and the same is tabulated in Table 1. The value of C/N ratio, OC, TN, K2O, P2O5, and NPK evidently portrays the shortcoming in terms of nutrient availability. Though it is highly enriched in organic carbon and thus the same can be effectively utilized as a soil preconditioner. Ayilara et al. (2020) also reported a similar finding, where the city compost sourced from MSW lagged major plant nutrients. RDF Characterization Processed trommel rejects constitute cloth, rexine, leather, jute, paper, plastics, coir and other inert contributed to RDF. The fraction of inert was as high as 37.2% of the overall RDF mass and it mostly constituted glass and sand. The combined weight of sand and glass fragments contributed 73.5% of the total inert, while the rest was stone and small brickbats. The higher level of silicon associated with the presence of glass and sand yielded siloxane and triggered the possibility of kiln corrosion. A detailed RDF analysis report is enclosed in Table 2. The values explicitly portray the quality of RDF is moderately lower and higher salts concentration is extremely prevalent. With relatively lower NCV and such high salt concentration, the above specimen will certainly pose a corrosion threat to the kiln and shall be either neglected as kiln feed or can be utilized after dilution with Grade III RDF quality. Further, such high ash generation will also induct high transportation and landfill charges. Leachate Characterization The Malkaram leachate lake is the end result of prolonged, slow, and steady mixing of the legacy leachate through the existing fissure cracks in the sheath rock bottom profile. Apparently, the concentration of leachate is significantly lower due to the dilution. Samples were analyzed in triplicates and the mean value is tabulated here in Table 3. The metal concertation and rest of the parameter values are well within the secondary treatment influent range, except for TDS. Thus, a modular aerobic biological treatment unit such as moving bed biofilm bioreactor (MBBR) or membrane bioreactor (MBR) would be a well-suited pick. However, a reverse osmosis (RO) system needs to be installed to get rid of the high TDS content. The permeate of RO can be reused back into the system. Whereas, the reject can be converted into dried powder through forced evaporation mechanisms. The higher concentration of salts in RDF collaterally justifies the elevated TDS level in leachate. In a leachate impact assessment study performed by El-Salam and Abu-Zuid (2015) the reported BOD/COD ratio of 0.69 is greater than double the value of 0.301 reported in Table 3. Though the difference in both the values are quite high, it is relatable and justifiable by the huge age difference of the source waste. The primarily characterized data is of a fresh leachate generated from regular MSW, while the later one is from a decade old waste that barely has any unstabilized organic content. Groundwater Contamination The obvious reason for downward leachate infiltration and osmotic movement facilitates groundwater contamination. Both surface and subsurface water samples were collected within the dump yard and the buffer zone and analyzed using the standard methods. The results are portrayed in Table 4. The slightly alkaline pH of the borewell sample is an indication of the ongoing anaerobic process. The dissolved oxygen value of 3.5 mg/L further validates the correlation. Higher TDS and hardness values are self-indicative of elevated salt concentration in source waste. Eventually, the same interfered with the RDF quality. Positively in the case of all the parameters, a successive decrement in pollution concentration has been spotted from dump ground towards the buffer zone. In a similar study conducted by Singh et al. (2016) at Varanasi, Uttar Pradesh the reported concentration of the parameters is significantly higher than reported in Table 4. The basic reason behind variation is the dissimilarities of the local soil profile. The sandy and clay loam soil profile of Varanasi allows a greater rate of percolation and infiltration. While the bottom sheath rock profile at Jawahar Nagar permits the only a minute to little percolation rate. The difference in percolation rate is directly correlated to the concentration levels in this case. Contrarily, Kurakalva et al. (2016) have reported much-elevated pollutant concertation both in ground and surface water for a study conducted at the same site in 2016. The higher concentration is relatable to the fact of the non-closure of the open dump back then. Capping activity had at Jawahar Nagar gained its pace 2018 onwards and capping for the primary section of 70 acres got concluded only during mid of 2019. Due to the decrement in runoff and percolation, the quality of both surface and subsurface water has improved drastically. Impact Assessment The odor and groundwater contamination are two of the primary issues that triggered a massive public agitation initially. The root causes of both the issues are identified as rainwater percolation and anaerobic digestion respectively. Eventually, the completion of the capping process would resolve both the problems effectively. Other non-tangential impacts include nausea; headache; irritation of the eye, nasal cavity, and throat; diarrhoeal diseases; vector-borne disease, cattle toxicity etc. Scientific capping can easily cater as the wholesome solution for all (Cortellazzo et al., 2020). Yu et al. (2018) had performed an extensive study to comprehend the relativity of respiratory sickness and MSW borne air pollution. The study made a couple of dreadful revelations such as gases released due to the anaerobic digestion of MSW such as methane, hydrogen sulphide, and ammonia incur detrimental impact on Lysozyme and secretory immunoglobulin A (SIgA). While SO2 was reported as the lung capacity and functionality reducer. Further, a gender-specific study executed by the same research group revealed, air pollution impacts more severely on male children than the female and retards immune functions. Presently, the area of 351 acres has been developed as Asia’s one of the largest state of the art municipal solid waste processing and disposal facility by Ramky Enviro Engineers Limited. This ensured zero dumping and no further environmental interventions. As legal compliance, the facility monitors the quality of groundwater and ambient air quality in and around the facility on monthly basis to assure the biosafety. The variation in concentration of various monitoring parameters between 2012 to 2020 is summarized in Figure 2. The concentration of each of the parameters are showcased in ppm and a standard equipment error was settled at 3% for respirable dust sampler and multi-gas analyzer (Taheri et al., 2014). Despite all parameter values have gradually increased except for methane, the facility still managed to maintain them well under the regulatory limits. The decrement in methane concentration is directly correlated to the practice of aerobic composting and aeration-based secondary treatment that prevented the formation of the anaerobic atmosphere and henceforth methane generation. While for the rest of the parameters the increment in values is quite substantial and predictable due to the sudden escalation in MSW generation in the past decade in correlation with Gross domestic product (GDP) enhancement. The observed and interpreted impacts due to the elevated pollutant level are in-line with the georeferenced findings reported by Deshmukh and Aher (2016) based on a study conducted at Sangamner, Maharashtra. CONCLUSION The study critically analyzed and investigated every techno-environmental and socio-economic aspect correlated to open dumping. The bench-scale experimentation revealed the efficiency of the single liner scientific capping is fair enough to eliminate any further rainwater infiltration, however, it has no control over the generation of leachate due to the inherent moisture. Internal moisture related issue was anyhow compensated with pertinent compaction prior to dispose of the waste. Contrarily, both the products derived through the biomining process namely, compost and RDF lagged quality due to scantier nutrient content and higher salt and silicon content respectively. Besides, impact assessment studies concede the pollutant concentration in groundwater in and around the plant has drastically diminished post-July 2019 due to the partial completion of waste capping. It also abetted lowering the dust and odor issues relatively in the surrounding. ACKNOWLEDGMENT The authors would like to sincerely acknowledge GHMC, Hyderabad Integrated Municipal Solid Waste Limited, and Ramky Enviro Engineers Limited for enabling us to pursue the sample collection and other necessary onsite activities. Further, the authors would like to register profound acknowledgment to EPTRI for supporting us with the essential experimental facilities. REFERENCES Sharma, A., Gupta, A.K., Ganguly, R. (2018), Impact of open dumping of municipal solid waste on soil properties in mountainous region. 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AbstractFertilization can be optimized and managed during the flue-cured tobacco growing period by studying the response of soil and microbial biomass stoichiometric characteristics to fertilization. In this study, we investigated the effect of compound fertilizers combined with microbial fertilizer treatments on the stoichiometric characteristics of the rhizosphere soil and the limitations of microbial resources during the flue-cured tobacco growing period. The results indicated that soil and microbial C:N:P varied greatly with the growing period. The effect of sampling time was usually greater than that of fertilization treatment, and microbial C:N:P did not vary with the soil resource stoichiometric ratio. The microbial metabolism of the tobacco-growing soil was limited by phosphorus after extending the growing period, and phosphorus limitation gradually increased from the root extension to the maturation periods but decreased at harvest. The rhizosphere soil microbial nitrogen and phosphorus limitations were mainly affected by soil water content, soil pH, microbial biomass carbon, and the ratio of microbial biomass carbon to microbial biomass phosphorus. Applying microbial fertilizer reduced phosphorus limitation. Therefore, applying microbial fertilizer regulated the limitation of microbial resources by affecting the soil and microbial biomass C:N:P in flue-cured tobacco rhizosphere soils.

Afforestation is an important and effective way to curb wind-sand hazards in the Alxa Desert. However, over-afforestation makes soil drying occur frequently. The formation of a soil drying layer is seriously restricting the effectiveness of vegetation construction and regional ecological stability. To clarify the process of soil desiccation in Haloxylon ammodendron plantations and determine the suitable planting years, a typical H. ammodendron plantation in this area was selected as the research object, and the soil moisture variation characteristics of this sand-fixing vegetation region with vegetation age were analyzed. The analysis results on soil water supply, consumption, and balance showed that the soil water storage in 0–400 cm soil layer of H. ammodendron plantation varies significantly in different ages. The soil water storage in 0–11 years old was the largest, and the soil water supply was greater than the soil water consumption. The soil water storage in profile increased with the increase of precipitation, the soil water storage of H. ammodendron at 11–22 years old increased first and then decreased with precipitation, and the inflexion existed in 16.5 years old. The soil water consumption of H. ammodendron plantation at 22–46 years old was greater than that of soil water supplement, and the soil moisture appeared negative balance continuously. Therefore, to prevent further deterioration of soil moisture ecological environment in the H. ammodendron plantation and to promote the sustainable development of afforestation in desert areas, thinning measures are suggested when the growth period reaches 16.5 years. The research results could provide scientific basis for afforestation and soil dry layer regulation in the Alxa desert.

Peat is a problematic soil which has a low shear strength characteristic. Addition of cement can improve the properties and strength of peat soil. This paper presents the findings of the shear characteristic of cement stabilized amorphous peat under consolidated undrained (CU) triaxial test. Three different natural moisture contents of peat which are 1210%, 803% and 380%, were stabilized using cement with water to additive (W/A) ratio of 2.0 and 3.0. CU triaxial test was conducted to the specimens after cured for 90 days. The shear parameters and characteristics were investigated towards the change of W/A ratio of the samples with different moisture contents. The result shows that the stabilized peat specimens exhibited ductile behavior and were sensitive to the over consolidation. The total and effective cohesion (ccu, c′) of the stabilized peat were found to be greater at W/A ratio of 2.0 compared to W/A ratio of 3.0, and greater at lower initial moisture content specimens. The total and effective friction angles (φcu, φ′) are ranged from 14o to 27o and 36o to 47o consecutively and found to be increased upon the increase of W/A ratio except for the specimens with moisture content 1210% and 803% in term of total friction angle.

Kuttanad region in Kerala, India, is a place that predominantly consists of soft soil formations with low shear strength and low water resistance rendering them problematic for construction purposes. Pavements constructed on such soft deposits have been subjected to structural rutting and the high erodibility of the in-situ soil necessitates the need to use suitable ground improvement techniques. The present environmental scenario demands the implementation of sustainable techniques for ground rejuvenation and effective stabilizers for enhancing engineering properties. This study investigates the amelioration of Kuttanad soft soil using chitosan as a soil amendment to improve its durability and erodibility characteristics. The untreated and chitosan-treated samples were exposed to 5 h of wetting cycle followed by 43 h of drying cycles until their failure. The unconfined compressive strength (UCS) of samples prepared with different dosages (0.5, 2, 4%) and cured for 14, 28, 60, and 90 days was evaluated at the onset and after each drying cycle to measure their durability index. Kuttanad soil was amended with 2% and cured for 90 days withstood five cycles with a UCS of more than 1,000 kPa. The drip erosion tests were used to check the erodibility performance for the aforementioned different dosages and curing periods. The 2% and 4% chitosan amended samples resisted the entire test duration of 10 min indicating the highest water erosion resistance. The findings of the current study evaluated through durability and erosion tests reinforced the effectiveness of chitosan as an effective biopolymer for soft soils subjected to constant water attack and can be easily implemented in places with such vulnerability. A typical earthen canal lining amended with chitosan reduced the carbon emissions by 8.74 and 7.44 times compared to conventional amendments like lime and cement in Carbon Footprint Analysis.

Cemented paste backfill (CPB) is fine-grained soil undergoing cementation. It is widely used in underground mining operations for ground support and mine waste (tailings) disposal. In the field, CPB may be placed in one layer (continuous filing), or multiple layers (discontinuous or sequential filling). Till today, no studies have addressed the effect of the different filling strategies on the response of CPB during cyclic events by using the shaking table technique. This manuscript presents new findings of investigating the effect of the different filling strategies of CPB on its geotechnical response to dynamic loading. CPB samples were prepared with different scenarios, including one Layered-CPB (discontinuous filling) sample at which each layer was cured to different curing time, and two unlayered-CPB (continuous filling) that were cured to 2.5 hrs and 4.0 hrs, respectively. All samples were exposed to same cyclic loading conditions using 1-D Shaking table. Geotechnical parameters or characteristics, including pore-water pressure, settlement, volumetric water content and liquefaction susceptibility were monitored or determined before, during, and after shaking. Obtained results indicate that Layered-CPB samples are resistant to liquefaction under the studied loading conditions, while the unlayered-CPB samples are prone to liquefaction under the studied conditions when they are cured to less than 4.0 hrs of curing time.

Expansive soil is a problematic soil which found in wide part of the world that has a high degree of sensitivity, nature of expansion and shrink behavior during water adding and removing this caused insufficient bearing capacity, excessive differential settlement and instability on excavation and embankment forming those conditions accelerate damage of building structure, road highway and dam. Attempt to undertake construction in such type of soil result will be bearing capacity failure, settlement problem. One of the well-known application of Lime and fly ash were improve Atterberg limits, compaction characteristics, bearing capacity and prevention of swelling problem of expansive clay that is why the main reason to select lime and fly ash in this project, both are good binding material to increase the cohesion force and shear strength of soil and assured to established rigid pavements and foundations. The mixing proportion of lime, fly ash and combination of lime and fly ash are (0%, 2 %, 4 % ), (10%, 15% ,20% ), (2 %+10 %, 2 % +15 %, 2 % +20 %) and (4 %+10 %, 4 % + 15 % , 4 %+ 20 %) with expansive soil respectively and then explored how much it modify the characteristics of soil like maximum dry density moisture content, consistency limits, FSI, UCS and CBR value which compare to untreated soil. Lime and fly ash treated soil carried out various tests Such as Moisture content test, consistency limit, compaction test, Unconfined Compression swelling index test and California bearing ratio test then after justify weather the bearing capacity of soil is good or not . Classification of soil was determined by conducting plasticity index and swelling index tests. Effect of lime and fly ash on soil index properties were assessed by conducting Atterberg limits test, strength of soil were assessed by conducting compaction test, UCS tests and CBR test and swelling properties were checked by conducting swelling index test. Expansive clay soil were mixed with lime, fly ash and combination of lime - fly ash by replacement process of soil and then cured for 7, 14 and 28 days.