Horizontal variation in trace elements and soil characteristics at Siloam and Tshipise geothermal springs, Limpopo Province, South Africa

The Limpopo Province is the location of 31% of South Africa’s geothermal springs. The springs at Siloam and Tshipise are among those springs which fall into the ‘scalding category’ with average temperatures of 67.7°C and 54.6°C, respectively. The aim of this study was to determine the horizontal variation in trace element concentrations and soil indicators in surface soil associated with the geothermal springs at Siloam and Tshipise. Results show that, in general, the trace element concentrations present in the soil decrease with horizontal distance from the springs. Water and soil samples were collected from May to July 2014, with the soil sampled at 0–15 cm depth at 5 m intervals in the horizontal distance from the geothermal spring. The physicochemical parameters of the water were determined as well as the trace elements. The soil samples were digested using microwave digestion and trace elements were determined using an inductively coupled plasmamass spectrometer (ICP-MS). Soil indicators – pH, soil organic matter (SOM) and soil water retention (SWR) – were also determined. The resulting data were subjected to both descriptive and factor analyses. Results showed only one factor determining the variation in geothermal water, attributed to the rock–water interaction in the deep aquifer (geology); two factors were obtained for variation in soil indicators and trace element concentrations, attributed to spring geology and the soil pedogenesis. There was a strong correlation between the trace elements and soil indicators at the 95% confidence level. There is generally a positive correlation between the trace elements and soil indicators if the soil pH, SOM and SWR are high; in these instances most of the trace elements in the soil will also be relatively high. A two-factors-without-replication ANOVA (p ˂ 0.05) showed that there is a significant difference in trace element concentrations at different distances.Keywords: geothermal springs, trace metals, soil indicators, rock-water interactions, soil pedogenesi

Human health aspects related to the ingestion of geophagic clayey soils from the Free State and Limpopo provinces, South Africa

Published ArticleStudies were undertaken in the Limpopo and Free State Provinces of South Africa to understand the beliefs, perceptions and health implications associated with geophagia. Questionnaires administered to 225 geophagic females covered their demographic details, their reasons for ingesting geophagic clayey soils and their perceptions regarding associated health conditions and implications. Respondents ingested clayey soils for body cleansing, craving, nutrient supplementation and weight loss. Some respondents considered the soils harmful, and < 50% of respondents had some knowledge of the contents of soils they ingested. Medical reasons in support of geophagia included lack of knowledge on the health implications of the practice. Medical consequences associated with geophagia may have occurred as a result of a lack of knowledge of the health implications of the practice. A clear need for educating geophagic individuals regarding the health implications of geophagia is called for

Health status of learners of educational institutions within Selebi Phikwe Ni-Cu mine area, Botswana

Published ArticleHealth effects associated with Ni-Cu mining on learners living within the mining area at Selebi Phikwe were investigated through the administration of questionnaires. Results depicted learners suffering from a wide range of different symptoms and illnesses. 70% of the learners complained of coughs, 77% had influenza / common cold, and 80% had headaches. The repeated coughing, constant influenza / common cold and persistent headaches from which learners suffered, were very significantly higher than those at the control site; and incidences of their occurrence increased with closeness to the mining area. The unusual high occurrences of these ailments and illnesses coupled with associated diseases among learners were attributed to several environmental factors including contaminated particulate air matter (PAM) (rich in sulphur and heavy metals) linked to the mining and smelting of Ni-Cu

Mineral Constituents and Kaolinite Crystallinity of the <2 μm Fraction of Cretaceous-Paleogene/Neogene Kaolins from Eastern Dahomey and Niger Delta Basins, Nigeria

This study examines the mineral composition and kaolinite crystallinity of Cretaceous and Paleogene/Neogene kaolins from Nigeria based on X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy data of the <2 μm fraction. The purpose of this was to assess the minerals present, structural order, and possible industrial applications of the kaolins. A total of twenty-eight (28) samples comprising of fifteen (15) Cretaceous and thirteen (13) Paleogene/Neogene kaolins were analysed. The XRD results showed that both the Cretaceous and Paleogene/Neogene kaolins have kaolinite as the dominant phase followed by quartz with anatase, hematite, and goethite occurring in minor quantities. Based on the mineralogical composition, the Paleogene/Neogene deposits were classified as sandy kaolin and the Cretaceous deposits were classified as pure kaolin. The kaolinite structural order for the Cretaceous pure kaolin was higher than that obtained for the Paleogene/Neogene sandy kaolin with more quartz, iron, and titanium oxides. The economic consideration of the deposits showed that the sandy kaolin type can be used in pigment industrial applications whereas the pure kaolin type can be used in refractory, fiberglass, and ceramic industrial applications

Effect of firing on colour of clayey materials applied to traditional ceramics

Increasing demand for use of clayey material in the traditional ceramic industry whereby clayey materials are fired at < 1300 oC, motivated this work, which focused on understanding the effect of firing on colour of clayey materials from Botswana, Mozambique, Pakistan, Senegal and the United States of America (USA). The colours of raw, fired, chemically bleached and magnetically separated clay samples were observed as one of the determining criterion for their suitability for use in the ceramics industry. Except for one sample obtained from South Africa, all the other samples of clayey materials were found to be suitable for the fabrication of fine and coarse ceramic products. However, other indicative tests such as particle size determination, mineralogical and chemical compositions, clay shrinkage as well as clay plasticity should be performed before a final decision on the use of the clayey material is reached at. (Botswana Journal of Technology: 2003 12(1): 13-18