Browsing by Author "Abdulhameed, Adamu"

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Microwave synthesis of Carboxymethylcellulose (CMC) from Rice Husk
(IOSR Journal of Applied Chemistry, 2019-12-07) Abdulhameed, Adamu; Mbuvi, Harun M.; Changamu, Evans O.; Maingi, Francis M.
Carboxymethylcellulose is an important non-toxic cellulose derivative which plays vital roles in paper coating, pharmaceuticals, food, detergents, and others. Research work involving the extraction of cellulose from agricultural biomass and its modification cellulose using a microwave has been reported, but not much work has been done on the rice husk, thus helping in managing associated waste. In this study, cellulose extracted from rice husks was used as the raw material for the synthesis of food-grade carboxymethylcellulose (CMC). In the process of the synthesis of carboxymethylcellulose from rice husk, cellulose was carried out by alkalization, an etherification process, using sodium hydroxide (NaOH) and monochloroacetic acid (MCA). Characterizations of CMC products was carried out by Fourier Transform Infrared (FTIR) spectroscopy and Xray Diffraction (XRD). The reaction conditions optimized include power (microwave), sodium hydroxide concentration, amount of monochloroacetic acid and reaction time. The degree of substitution (DS) was determined using a potentiometric titration method and the maximum DS of 0.79 was obtained when 30% NaOH was used.
Physical-Chemical Characterization of Soils in Selected Potato Growing Areas of Molo, Nakuru County Kenya
(SSRG International Journal of Agriculture & Environmental Science, 2020-08-07) Maingi, Francis M.; Mbuvi, Harun Mbatha; Abdulhameed, Adamu
Characterization of soils in selected potato growing farms of Molo, Nakuru County in Kenya was compelled by the decline in potatoes acreage yields observed in the study area over the years. In the pursuit of reasons behind the decline, this study determined levels of some key soil fertility indices in soil samples obtained from selected farms. Four farms that have been in intensive potatoes farming were used. The soil was randomly collected from a depth of 0-10 cm separately for all the investigated sites. Collected site-wise samples were air-dried, ground, and passed through a 2 mm sieve and stored in plastic containers ready for analysis. Analytical techniques employed were Walkley black for carbon, Kjeldahl for nitrogen, standard wet chem soil analysis, saturation method for water porosity, glass electrode determined soil pH, bulk density, particle density, water holding capacity were determined by methods of Keen box. The mean levels of essential soil fertility indices obtained were; soils pH (5.46 ± 0.43), soil bulk density (g/cm3) (1.03 ± 0.01), particle density (2.51 ± 0.08), water holding capacity (%) (36.07 ± 2.57), porosity (0.59 ± 0.01), exchangeable cations (uS/cm) (83.63 ± 14.22), cation exchange capacity (meq/100g) (18.48 ± 0.89), organic carbon (%) (3.50 ± 0.24), total nitrogen (%) (0.17 ± 0.03). Mean micro and macronutrients available (mg/Kg) were; phosphorous (7.11 ± 2.77), potassium (100.27± 8.32), calcium (198.2 ± 35.1), magnesium (20.97 ±4.28), manganese (15.26 ± 1.12), sulphur (2.31 ± 1.88), copper (0.59 ± 0.12), boron (0.38 ± 0.07), zinc (12.96 ± 2.04), sodium (8.61 ± 0.51), iron (147.92 ± 4.10). These findings reveal the extent of some fertility indices depletion in the soils and will form a base for decreased acreage yield of potatoes in this region. The results further form the baseline for future research on the working acreage of key soil fertility indices required for remediation.
Pyro-processed Coconut Fibre for Removal of Lead Ions from Aqueous Solution
(American Journal of Chemistry and Pharmacy, 2026-05-25) Kasimu, Titus M.; Maingi, Francis M.; Mbuvi, Harun M.; Ng’ang’a, Margaret M.; Abdulhameed, Adamu
Approximately 80% of the population in developing countries lacks access to clean, safe water. A major source of water contamination is heavy metal ions, which pose great risks to human health. This is expected to increase with the projected population and industrial growth if immediate remediation is not taken. Current operational methods for removing the heavy metal ions in wastewater include: chemical coagulation, ion exchange, electrochemical methods, adsorption using activated carbon, natural zeolite, membrane process, ultra-filtration, among others, which are uneconomical due to high costs and unaffordable to low-income earners. Coconut fibres are locally available agricultural waste that can be converted by activation into adsorbents for water remediation due to their fineness and large surface area. This study reports the synthesis and characterization of coconut fibre charcoal (CFC) and activated coconut fibre charcoal (ACFC) to remediate water contaminated with Pb2+ ions. This involved burning dry coconut fibre in a limited amount of air to obtain coconut fibre charcoal followed by dissolving fine powder of charcoal in 2 M phosphoric acid for 24 hours at a temperature of 25 ºC to obtain activated coconut fibre charcoal. The adsorbents were characterized using FT-IR and SEM. Batch sorption studies were carried out while varying parameters of contact time, shaking speed, temperature, adsorbent dose, pH, and initial concentration of metal ions in solution. Residue Pb2+ ion concentrations were determined using atomic absorption spectroscopy (AAS). The FT-IR results showed absorption peaks at 1423 cm-1 and 840 cm-1 attributed to symmetric –COO- stretch and -OH deformation in ACFC adsorbent, these peaks shifted to 1384 cm-1 and 813 cm-1 while PO4- aromatic strain vibration in ACFC disappeared upon saturation of ACFC with Pb2+ ions respectively. SEM analysis showed pores of different sizes and shapes in ACFC compared to a rigid, concrete, and smooth surface upon saturation with Pb2+ ions. Adsorption data for Pb2+ ions best fitted into the Freundlich model with maximum adsorption capacities of 32.09 mg lead/g activated coconut fibre charcoal. The results from this study suggest that coconut fibre charcoal and activated coconut fibre charcoal are potential adsorbents of Pb2+ions.
Synthesis and characterization of cellulose phosphate-based superabsorbent hydrogels from rice husk under microwave heating
(Science Direct, 2025-06-07) Abdulhameed, Adamu; Mbuvi, Harun; Changamu, Evans; Githinji, Irene; Maingi, Francis M.
The current study deals with the synthesis and characterization of superabsorbent hydrogels from rice husk cellulose. Rice husks are slow decomposing waste from the milling of rice with an estimated composition of cellulose (50 %), lignin (25–30 %), silica (15–20 %), and moisture (10–15 %). The aim of using it as a source of cellulose was to provide an alternative use of the otherwise incinerated waste product that is abundantly available in rice producing countries like Kenya. Cellulose-based hydrogels continue to attract interest because of their biocompatibility and biodegradability for which they have found use in several fields including drug release, packaging films, agriculture, among others. The cellulose was extracted from rice husk and crosslinked with phosphoric acid under microwave oven heating. The products were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, x-ray diffraction and x-ray fluorescence. Four parameters namely, heating time, microwave oven power out-put, percent swelling and the amount of cross-linker required for complete reaction were optimized for the synthesis of superabsorbent hydrogels. The optimum percentage swelling was found to be 877 %, heating time of 3 minutes, microwave oven power output of 420 watts (level 6 on the microwave oven dial), 10 mL of cross-linker when 2 g cellulose was used. The efficacy of the hydrogel in maize growing was determined by planting maize in pots in a greenhouse under varied hydrogel dose treatments and measuring growth and yield parameters over a period of twelve weeks. The values of plant growth and yield parameters were found to increase with hydrogel dose with the best results being observed among maize plants grown under the hydrogel dose of 5 g per pot. It was observed that the maize plants in pots treated with hydrogel continued to thrive while those in pots without any hydrogel dried off as expected when rains fail. These results are significant in that they demonstrate that rice husk cellulose-based hydrogels are efficacious in maize growing in a greenhouse.
Synthesis of Silicon Nitride from Rice Husk and Sugarcane Bagasse Ashes
(Journal of Water technology and Treatment methods, 2018-01-22) Abdulhameed, Adamu; Mbuvi, Harun M.; Changamu, Evans O; Maingi, Francis M.
Silicon nitride (Si3N4) SNA, SNB, SNC and SND were synthesized by hydrothermal process at temperature of 100oC, 150oC, 200oC and 300oC using Rice Husk Ash (RHA) and Sugarcane Bagasse Ash (SBA) respectively. The percentage of silica ranges from 90.10 to 94.19 with minute impurities.Based on their infrared spectra, for SNA absorption band at 470.6 cm-1 is attributed to Si-N (stretching), which were also observed with SNB, SNC and SND, a weak band at 671.2 cm-1 which is characteristic of a silicon nitride Si-N-Si stretching vibration was observed, for SNC, peak at 574 cm-1 attribute to α-silicon nitride, as temperature increases the spectrum becomes sharper. X-ray diffraction pattern indicates that SNA material contained 64.6% α-phase and 27.8% β-phase silicon nitride. Therefore, rice husks and sugarcane bagasse have great potential as a raw material for producing Si3N4, by the hydrothermal method
Thermodynamic, Kinetic and Equilibrium Studies of Pb (II) Ions Adsorption Using Ordinary Clay/Rice Husk Ash Based Geopolymers
(IOSR Journal of Applied Chemistry, 2018-08-08) Maingi, Francis M.; Ng’ang’a, M. M.; Mwangi, H.; Mbuvi, H. M.; Abdulhameed, Adamu
One key global challenge is the existing disparity in water distribution resulting to millions of people lacking access to safe clean water. It is currently assessed that 1.1 billion individuals on the planet lacks access to improved quality water supplies. This is aggravated by the looming climate change and increased pollution threats posed by industrialization and population growth. Use of adsorbents for water treatment is preferable due to simplicity of the technique and cheap materials involved. Geopolymers can be easily synthesized hydrothermally using alumina and silica and possess amorphous surface for use as adsorbents. Clay minerals have been reported to contain alumina and silica and previous research show that rice husk ash as well contain substantial amounts of silica. Geopolymers can be easily synthesized hydrothermally using alumina and silica and possess amorphous surface that is useful for adsorption. Hence this work reports information on adsorption of Pb (II) using geopolymers GP-1, GP-2 and GP-3 synthesized with SiO2/Al2O3 ratios of 4.16, 4.18 and 8.29 respectively. Adsorption of metal ions was found to increase from 70.54%± 0.43 to 90.23% ± 0.04 with increase in Si/Al ratio from 4.16 to 8.29 in geopolymers. Equilibrium studies unveiled that experimental data for adsorption of Pb (II) ions best fitted in modified Langmuir Freundlich model. The adsorption capacities of 27.0, 79.58 and 209.9mg/g were obtained for GP-1, GP-2 and GP-3 respectively. Adsorption thermodynamics showed the process corresponded on spontaneous physiosorption activated by increase in temperature. Kinetic study on adsorption of Pb (II) ions onto clay based geopolymers was a Pseudo second order. This information may facilitate the development of optimized procedures for wastewater treatment, thus providing an alternative solution to environmental menace caused by heavy metal pollutants.