Browsing by Author "Vegi, Maheswara Rao"

Now showing 1 - 7 of 7
  • Thumbnail Image
    Item
    Amendment of soil water retention and nutrients holding capacity by using Sugar Cane Bagasse
    (Enviro Research Publishers, 2019) Chacha, Mwita Solomon; Andrew, Banyikwa; Vegi, Maheswara Rao
    Sugarcane bagasse (SCB) is byproduct of sugarcane industry can be used as soil amendments to improve soil hydro, physical-chemical characteristics. It also provides reasonable economic means to recycle these in an environmentally friendly manner. The soil samples were studied for different soil characteristics collected from different sites of Dodoma city, Tanzania. Soil sample with poor water holding capacity selected and made into six treatments by different percentages of sugarcane bagasse 0, 2, 5, 10, 20 and 100% in triplicates for each treatment. The result showed that water holding capacity of the soil increased from 26.85 to 84.08 % representing 3.16 times. The soil of Dodoma have low organic matter (438.6 - 1126.6 mg/kg), and deficient in K+ (0.5 cmol/kg), Ca2+ (2.8 cmol/kg), Mg2+ (1.3 mg /kg), Na+ (1.03 cmol/kg) and cation exchange capacity (5 cmol/kg). The available K+ , Ca2+, Mg2+ contents of soil increased by 13.87, 22.79, 33.13 and 43.61% with the application of 2, 5, 10 and 20 % of sugarcane bagasse, respectively. Different levels of SCB positively influence the hydro, physico-chemical properties of soil. Utilization of SCB as organic fertilizer was found to save the water cost and chemical fertilizer along with minimizing environmental pollution. Application of 10% of sugarcane bagasse was found to be the standard dose to achieve important hydo, physico-chemical properties of soil to a required level.
  • Thumbnail Image
    Item
  • Thumbnail Image
    Item
    Chronostratigraphic studies of the Ootun area revealing the late holocene plume volcanism of the Oldoinyo Lengai, Ngorongoro, Tanzania
    (Hindawi, 2022) Makongoro, Mohamed Zengo; Vegi, Maheswara Rao; Vuai, Said Ali Hamad; Msabi, Michael Mwita
    Oldoinyo Lengai has been a subject of international attention for geoscientists because of its uniqueness. The mountain is the world’s only active natrocarbonatite volcano whose recent activities are well documented. However, little is known about its eruptive history during the Holocene. One way of uncovering past volcanic activities is through chronostratigraphic studies. A rare stratigraphic sequence in the Ootun area containing buried tephra beds and paleosols is presented in this article. The beds suggest that the nearby active Oldoinyo Lengai volcano experienced the main plume volcanism during the late Holocene. This work presents the lithology of the area, estimated deposition period, and elemental and mineralogical compositions of strata, and establishing similarities between ash properties and information from previously reported chemistry and eruptions of the Oldoinyo Lengai volcano. Energy dispersive X-ray fluorescence, X-ray diffractometry, and accelerated mass spectrometry techniques were used for elemental, mineralogical, and radiocarbon dating analyses. A 1.3-m vertical soil profile revealed three major strata: topsoil, tephra bed, and paleosols. The paleosols are presumed to have been topsoil of the Ootun area during the Holocene. Subsurface tephra layers were found to contain similar properties to the volcanic material of the Oldoinyo Lengai. Based on the experimental findings and literature data, the study reports the occurrence of two major plume eruption events from the Oldoinyo Lengai, which happened around the minimum (oldest) age of and 771 AD. This work is essentially important in demonstrating the relevance of the region’s tephra chronostratigraphic studies by revealing the prospect of collecting additional scientific data on past geological processes and paleoenvironmental conditions of northern Tanzania.
  • Thumbnail Image
    Item
    Defluoridation of aqueous solution using raw and surface modified biosorbents prepared from adansonia digitata fruit pericarp
    (Taylor & Francis, 2021) Mihayo, David; Vegi, Maheswara Rao; Vuai, Said Ali Hamad
    In some parts of Tanzania, there are higher fluoride concentrations in water bodies that affect public health. This work reports on water defluoridation using bio-sorbents prepared from Adansonia digitata fruit pericarp which is an agricultural waste. The raw and surface modified Adansonia digitata fruit pericarps were prepared, characterized, and used for defluoridation of the aqueous solution. The surface-modified adsorbent has better physical and chemical characteristics for bio-sorption. FT-IR spectra of adsorbents revealed that carboxyl, hydroxyls, carbonyls, and halogen groups are present on the adsorbent. The maximum removal efficiencies of raw and surface-modified bio-sorbents were 67.61 and 91.91% respectively which means surface modified bio-sorbent is effective for the removal of fluoride. Maximum adsorption efficiency was achieved with an initial concentration of 27.50 mg/L, the final concentrations of fluoride after adsorption were 8.907 and 2.225 mg/L for RADFP and SMADFP respectively. The adsorption capacity, q0 of RADFP and SMADFP are 0.2475 and 0.3173 mg/g, respectively. The values adsorption intensity, n is 1.3988 for RADFP and 1.1714 for SMADFP which lies between 1 and 10 indicating a favorable adsorption process. The adsorption data fitted well with the Freundlich adsorption model and Pseudo second order kinetics. Therefore, the surface-modified Adansonia digitata fruit pericarp is a potential bio-sorbent for the removal of fluoride ions from water
  • Thumbnail Image
    Item
    Defluoridation of drinking water using coalesced and un-coalesced mica
    (Springer, 2020) Hussei, Idd Ally; Vegi, Maheswara Rao
    This is a sorption study that focused on the use of mica clay mineral grouped into mica untreated, activated mica at 800 °C, mica impregnated separately with iron and aluminium for defluoridation of water. In this study, characterization of adsorbent was done by using XRF and XRD and quantification of fluoride by using fluoride ion selective electrode. Characterization of adsorbent showed the presence of SiO2, CaO, P2O5, Fe2O3 and Al2O3 in the adsorbent. XRD exhibited higher composition of illite, calcite, quartz and albite. Batch experiments were conducted by using a homogeneous mixture of water having 16 mg/L of fluoride. The removal efficiencies of mica alone, activated mica at 800 °C, mica impregnated with iron and mica impregnated with aluminium were found to be 76.02%, 90.21%, 94.40% and 96.88%, respectively. Activated mica and coalesced mica are better adsorbents than mica alone. The optimized pHs were 7.3, 4.4, 7.5, doses of 10, 9 and 8 g, contact time of 40, 35 and 30 min for activated mica, mica impregnated with iron and mica impregnated with aluminium, respectively. The adsorption process obeyed Freundlich model for mica impregnated with aluminium indicating monolayer mechanism, whereas activated mica and mica impregnated with iron agreed with both Freundlich and Langmuir models indicating both monolayer homogeneous and heterogeneous surface conditions. From the kinetic perspective, the fluoride adsorptive reaction followed the pseudo-second-order model. Therefore, activated and modified mica are alternative adsorbents for defluoridation of water.
  • Thumbnail Image
    Item
    Geochemical, mineralogical, and geomorphological characterization of ash materials as a tracer for the origin of shifting sands near Oldupai Gorge, Ngorongoro, Tanzania
    (Hindawi, 2022) Makongoro, Mohamed Zengo; Vegi, Maheswara Rao; Vuai, Said Ali Hamad; Msabi, Michael Mwita
    Shifting sand (SS) is a single dune-shaped mass of black ash material moving across western Ngorongoro in northern Tanzania. The moving sand has become an important tourist destination for several decades. Despite being part of the important geosites at the Ngorongoro Conservation Area, the nature, origin, and behaviors demonstrated by SS remain poorly understood. This work contributes toward understanding the nature and identification of the possible origin of the SS through the correlation of geochemical, mineralogical, and geomorphological data of ash material from four selected locations in the study area. To achieve this goal, elemental, mineralogical, and morphological characterization of ash samples was performed by energy-dispersive X-ray fluorescence, polarized petrographic microscopy, automated sieve shaker, and binocular microscopy techniques, respectively. Correlation studies were based on magnesian-ferriferous associations, similarities in mineralogy, particle size, shape, and distribution patterns of ash materials, and weather data. There are close similarities in the chemical compositions among ash samples of SS, Ootun area, and Oldoinyo Lengai. Augite and magnetite minerals appear only in samples of SS, Ootun area, and Oldoinyo Lengai, while hornblende appears only in the samples from the Ngorongoro crater. Oldoinyo Lengai rock petrography revealed significant amounts of augite minerals. Blocky and elongated-shaped ash particles dominate the samples from SS, Ootun area, and Oldoinyo Lengai. The particle size of ash materials decreases westwards across the study site. The distribution patterns of ash material align with the west-south-west wind direction. Based on these findings, the study concludes that SS and Ootun ash could be tephra depositions resulting from past volcanic eruptions of Oldoinyo Lengai.
  • Thumbnail Image
    Item
    An investigation on effectiveness of grafted potato starch as an adsorbent for hard water treatment
    (Hindawi, 2020) Mgombezi, Desderia; Vegi, Maheswara Rao
    Water is essential for the life of all living organisms. But water with very high hardness (Ca2+ and Mg2+) is harmful to health. In addition, hard water clogs the pipes in the industries. ) is study was conducted to investigate the effectiveness of grafted potato starch as an adsorbent for hard water treatment. Four samples of well water from Nzuguni, Ng’hong’hona, Kisasa, and Swaswa of Dodoma municipal were analyzed by the EDTA titrimetric method. The results showed the highest hardness of 547 mg/L in the water sample of Ng’hong’hona from which hardness was removed. The maximum percentage removal of 74.50% was achieved at 80 minutes of optimum contact time. The optimum adsorbent dose is 3.5 g at which 80.7% of removal was achieved. The optimum temperature was 80°C at which 75.8% of removal achieved. An increase in pH increased the percentage of removal up to a pH of 12 with 71.1%. The data obtained showed that the adsorption process fitted Langmuir type II isothermal model and pseudo-secondorder kinetic model with correlation coefficients of 0.9994 and 0.9940, respectively. Grafted potato starch has shown higher efficiency in hardness removal, and hence, this adsorbent is highly recommended for the treatment of hard water.