Browsing by Author "Kundu, Mercy"

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Analysis of Macro- and Microplastics in Riverine, Riverbanks, and Irrigated Farms in Arusha, Tanzania
(Springer Nature Switzerland AG., 2021-11-16) Kundu, Mercy; Komakech, Hans; Lugomela, George
Microplastics and macroplastics have been reported in different urban rivers and agricultural soil across the globe. However, the interlink between them has not been previously assessed. The present study evaluated the relationship between macro- and microplastics in the surface water and sediments in riverine, riverbanks, and soils from irrigated farms in Arusha, Tanzania. Detached pieces from macroplastics and suspected particles of microplastics from the samples were analyzed using the total attenuated reflectance–Fourier transform infrared spectroscopy. Statistical analysis showed that the number of microplastics in the sediments was higher than those in the surface water and that in irrigated farms was of four times higher than those found in riverine. Besides, the numbers of microplastics and macroplastics in the irrigation farms were exponentially related, while the macroplastics from the riverbanks had an inverse relationship with the rivers' profile elevation. Macroplastics of polyethylene type dominated in the riverbanks and irrigated farms with an occurrence frequency of 100%, while polystyrene was abundant in all analyzed microplastics samples. In addition, those irrigation farms adjacent to canals had a significant number of microplastics and macroplastics than the distant farms. This study provides new information for the region and others that divert water from an urban river for irrigation.
Diversity and quantity of macro-and microplastics in irrigation farms sourcing water from an urban river: a case of Arusha Tanzania
(NM-AIST, 2021-10) Kundu, Mercy
Increased concentration of plastics in urban rivers and agricultural farms causes degradation of river system functionality and reduces the productivity of agricultural soils, respectively. This study assessed the quantity and types of macro-and microplastics found in dependent smallholder irrigation farms downstream of Arusha city in Tanzania. The microplastics' concentration from the sites was visualized using dissecting microscope 40X, enumerated and categorized based on the shape, color, and sizes for soil samples. Then the suspected materials’ spectral were determined using the Attenuated Total Reflectance- Fourier Transform Infrared (ATR-FTIR). Afterwards, the confirmations and identifications of the polymers' types from spectral were confirmed using SiMPle Software. The average microplastic from the water column was 0.57 ± 0.27 items L-1 , sediment 0.17± 0.07 items g-1, while in the irrigation farms ranged from 102 to 728 items with a mean of 0.69 ± 0.35 items g-1 . However, no international standards have been developed to ascertain the pollution level, but the reported values are unsafe to the environment. Other studies conducted in similar conditions reported mean values within the range of values found in this study and more. Polyethylene was the dominating type of macroplastics evaluated from riverbanks and irrigation farms with a frequency of occurrence 100 %, while polystyrene was abundant in all microplastics samples. Farms adjacent to the irrigation canal had a greater number of microplastics and macroplastics. Thus this study reveals urban rivers as the primary sources of plastics pollution in the irrigation farms situated in flood-prone zones.
Spatial occurrence and variation of the active pharmaceutical compounds in rivers and groundwater systems in Arusha City, Tanzania
(Elsevier, 2024-06-30) Kundu, Mercy; Komakech, Hans; Sang, Joseph
This study investigated the occurrence of 11 pharmaceutical compounds in the rivers and groundwater systems of Arusha City, Tanzania. Each suspected individual residue of active pharmaceutical compounds in water matrices, was pre-concentrated using solid-phase extraction techniques and, then quantified using a liquid chromatography-mass spectrometer mass spectrometer (LC-MS/MS). The concentrations varied across the assessed rivers and groundwater systems. High concentrations of caffeine 520 ng/L were detected in the station downwards of a wastewater stabilization pond, discharging its partially treated effluent into the river, followed by stations whose rivers flowed through informal areas. Sampled points' located near the river's water sources reported fewer compounds with values below the detection limit, such as amoxicillin, paracetamols, and doxycycline. Except for sulfamethoxazole (94 ng/L) in the borehole, most of the concentrations detected in rivers were ten times higher than in boreholes. In addition, in boreholes, more compounds were identified in the monitoring than in the domestic ones, and concentration varied with depth of deep boreholes (25 m) were less abundant than shallow wells of less than 10 m. In conclusion, pharmaceutical compounds were frequently detected in both rivers and groundwater systems within Arusha City suggesting the need for understanding of their fates and associated risks.