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Papers by Chirangano Mangwandi

Molecules/Molecules online/Molecules annual, Feb 24, 2024

ABSTRACT This work describes a novel method of producing multicomponent fertiliser granules using... more ABSTRACT This work describes a novel method of producing multicomponent fertiliser granules using high shear granulation. The granulation process was optimised using the response surface methodology technique. The variables used in the optimisation process include granulation time, batch size, impeller speed and binder concentration. Granulation time, binder concentration and interaction between the batch size and granulation time were found to be the main factors affecting the granule median size. The product yield is mainly influenced by granulation time and binder concentration. The interaction between the impeller speed and batch size also have a significant influence on the product yield. Product yield (2–4 mm) of approximately 60% could be obtained with high sphericity and granule strength (> 0.5 MPa). A low product recycle ratio of about 2:3 can be obtained at the optimised process conditions, compared to typical recycle rations of 6:1 which are obtained in typical fertiliser plants.

Journal of environmental management, Aug 1, 2024

Particuology, Sep 1, 2023

Materials

In this research, a novel composite material composed of Metal-Organic Framework material (MOF) a... more In this research, a novel composite material composed of Metal-Organic Framework material (MOF) and graphite oxide was synthesized and evaluated as a possible drug-loading vehicle. HKUST-1, a MOF material originally designed by the Hong Kong University of Science and Technology, was used as a model porous material. The aim was to synthesize a drug delivery vehicle for modifying the release kinetics and solubility of poorly soluble drugs (BSC Class II drugs); these are drugs that are known to have poor bioavailability due to their low solubility. We used ketoprofen, ibuprofen, and felodipine as models for BSC Class II drugs. The drugs were loaded onto composite materials through adsorption. The adsorption of these three drugs into the matrix of HKUST-1/GO (graphite oxide), HKUST-1, and graphite oxide was compared. The loading efficiency of the drugs onto the carrier was dependent on the drug molecule and the composition of the drug carrier. The inclusion of graphite oxide in the drug...

Water Practice and Technology

A face-centred central composite experimental design scheme was used to find experimental conditi... more A face-centred central composite experimental design scheme was used to find experimental conditions this would result in producing magnetic bleached teawaste (MBTW) adsorbent material to have the optimum hexavalent chromium (Cr(VI)) removal capacity. The effect of treatment conditions, namely temperature (200 °C, 350 °C, 500 °C), duration of the heat treatment (2 h, 3 h, 4 h), the concentration of the iron chloride (0.02 g/g, 0.055 g/g, 0.09 g/g) added was investigated. The results obtained showed that the pyrolysis temperature and the amount of iron chloride added during treatment had significant effects on the performance of MBTW material in removal of both total chromium and Cr(VI). Increasing temperature from 200 °C to 500 °C, both Cr(VI) and total Cr removal would decrease. The material with optimum removal of Cr(VI) was used for the detailed adsorption study. The results from the detailed adsorption study indicated that the MBTW material has an excellent Langmuir removal capa...

Global Research & Innovation in Plastics Sustainability, Feb 4, 2021

ESAI Environ 2020 Colloquium : 'Ireland's Water, Energy & Environment in a Climate & Biodiversity Emergency', 2020

Environmental Geochemistry and Health, 2022

Mercury (Hg) is extremely poisonous and can be absorbed through touch, inhalation, or consumption... more Mercury (Hg) is extremely poisonous and can be absorbed through touch, inhalation, or consumption. In the living environment, Hg in contaminated sediment can be transferred into grass by the direct absorption through the roots or shoots. The intake of Hg due to Hg emissions may pose a threat to living bodies especially to human beings. The present study aims to provide a novel insight about total mercury (THg) and methyl mercury (MeHg) in a riparian grass (Cynodon dactylon (L).Pers) and sediments during the discharging phase (summertime at 145 m water level) in Three Gorges Reservoir (TGR-China); where C. dactylon is a dominant perennial herb in the riparian zone. Yet, the potential risk of Hg contamination in the riparian ecosystem is not thoroughly assessed in the dam regulated reservoir. This study was conducted in the riparian zones of the reservoir formed by a mega dam (Three Gorge Dam) which regulates the water levels during the summer and winter period in the TGR. Our results showed that riparian sediments were acting as a sink for THg and MeHg. Insignificant correlation of THg and MeHg was found between the amphiphyte C. dactylon and its surrounding sediments in the TGR. Bioconcentration factors values for MeHg were found higher than 1 in all study locations in the riparian zones in TGR, which could be due to action of certain bacteria/purely chemical-based methylation on inorganic form of Hg. Additionally, translocation factor indices also highlighted that the amphiphyte C. dactylon was MeHg accumulator in riparian zones. These results suggested that since riparian sediment was found acting as the sink for THg and MeHg during discharging phase, MeHg contamination in the amphiphyte C. dactylon in riparian zones was not caused by the riparian sediments but by other factors, for instance, the anthropogenic activities in the TGR. Finally, this study leads to conclude that amphiphyte C. dactylon can be used as biomonitoring agent for Hg pollution in the TGR.