2026-09-24T12:46:28Zhttps://bura.brunel.ac.uk/oai/request

oai:bura.brunel.ac.uk:2438/65872014-11-01T12:55:40Zcom_2438_23com_2438_58col_2438_3672col_2438_200

Jones, JG Hall, Grahame 2012-07-30T13:25:39Z 2012-07-30T13:25:39Z 1981 http://bura.brunel.ac.uk/handle/2438/6587 This thesis was submitted for the degree of Doctor of Philosophy and was awarded by Brunel University. Nitrification became the dominant nitrogen transformation in a number of lakes which accumulated ammonium, in hypolimnetic water, under aerobic conditions. The timing and duration of this activity varied between lakes but was characterized by decreasing ammonium, and increasing nitrate, concentrations. In Grasmere lake this phase was found to be due to the activity of planktonic chemolithotrophic nitrifying bacteria. The observed nitrate concentration increased during this phase and accounted for up to 15% of the total oxygen deficit of the hypolimnion. At similar in situ temperatures nitrification rates and nitrifying bacterial populations were greater in oxidised sediments than in the water column. Littoral sediments were more important than profundal sediments as sites of nitrification due to higher temperatures and the persistance of oxidising conditions to greater depths into these deposits. Within the littoral zone the physical characteristics of the sediment were important with organic rich deposits sustaining greater rates of nitrification than sandy sediments. Nitrate reduction was the primary determining factor of nitrate concentrations in sediment interstitial waters. Some observations on the culture of chemolithotrophic nitrifying bacteria from lakewater were discussed. Reviews of the methodology for nitrification research and nitrification in the lacustrine environment are presented. Submitted by Carolyn Bailey (carolyn.bailey@brunel.ac.uk) on 2012-07-30T13:24:49Z No. of bitstreams: 1 FullTextThesis.pdf: 12627646 bytes, checksum: 8c749ecb00c367fda84b0b15dcb8b777 (MD5) Approved for entry into archive by Carolyn Bailey(carolyn.bailey@brunel.ac.uk) on 2012-07-30T13:25:39Z (GMT) No. of bitstreams: 1 FullTextThesis.pdf: 12627646 bytes, checksum: 8c749ecb00c367fda84b0b15dcb8b777 (MD5) Made available in DSpace on 2012-07-30T13:25:39Z (GMT). No. of bitstreams: 1 FullTextThesis.pdf: 12627646 bytes, checksum: 8c749ecb00c367fda84b0b15dcb8b777 (MD5) The Department of the Environment, contract number D.G.R.480/32. en http://bura.brunel.ac.uk/bitstream/2438/6587/1/FullTextThesis.pdf English Lake District Nitrification Lacustrine environment Nitrate concentration Sediment A study of nitrification in lakes of the English Lake District Thesis