Manganese Geochemistry in Loch Bradan,
South-West Scotland

Daniel B. Short

My M.Sc. research was conducted at the University of Edinburgh in Scotland and entitled "Manganese Geochemistry in Loch Bradan, South-West Scotland". The research was supervised by Dr. John Farmer, professor of environmental geochemistry (presently serving as editor in chief of the journal 'Science of the Total Environment'). John introduced me to the world of lake sediments and the geochemical stories that they hold. He currently heads the Global Environmental Change Research Group in the School of Geosciences.

The aim of this project was to gain an understanding occurrence, levels and the geochemical cycling of manganese (Mn) and iron (Fe) in the water, soil and sediment of a Scottish drinking water reservoir. Manganese is a naturally occurring element that is found in rock, soil and water. It usually occurs together with iron and high levels of these heavy metals are a problem for many UK water companies producing discolouration and an unpleasant taste to the water, as well as staining laundry and forming deposits in pipes. According to the World Health Organisation no convincing evidence of toxicity in humans associated with the consumption of manganese in drinking waters exists, although only limited studies are available.

The reservoir (55° 14' 33'' N, 4° 28'  51''  W) was the property of South-West water authority who had approached the university for help with their manganese problem. Field sampling for this project was carried out with the aid of Alex Kirika (CEH Edinburgh). The CEH provided us with several devices including a sediment-water interface sampler known as the Jenkin corer. Sediment and soil samples were digested in concentrated acid solution and analyzed for iron and manganese on a Pye-Unicam Atomic Absorption Spectrophotometer.


Jenkin Corer.

Abstract: Manganese concentrations in Loch Bradan, south-west Scotland frequently exceed the E.U., W.H.O. and Potable Water Standard limits (50 mg l-1). Waters containing manganese concentrations above this level become turbid and highly unacceptable from the aesthetic viewpoint of the customer. Loch Bradan is situated in an area of high rainfall on the margins of the Loch Doon granite intrusion. The catchment includes manganese rich rocks and organic soils. There is little if any manganese concentration gradient in Loch Bradan waters. Loch Bradan sediments show characteristic diagenetic surface (0-1 cm) enrichments of manganese in the region of 1-4 %. Soil manganese concentrations are less than 1/1000 th of those found in sediments. Input streams to Loch Bradan contain higher concentrations in sediments compared with the loch itself. Two of the streams contain the highest concentrations of manganese of all streams in the Loch Doon granite intrusion. The high manganese concentrations found in the Loch, stream waters and sediments are a result of natural climatological, topological and pedological conditions encountered in this area.


View over Loch Bradan.


Loch Bradan, Scotland.


This is one of the organic chemistry labs in the University of
Ediburgh's Joseph Black building. The fume hood at the far end
of the room is where I digested this projects sediment samples.

Publications Resulting from this Work:

Short, D.B. (1995) Manganese Geochemistry in Loch Bradan, South-West Scotland. M.Sc. thesis, The University of Edinburgh.