Multivariate Monitoring of Wastewater Treatment Processes in Pulp and Paper211 Industry. Acta Polytechnica Scandinavica, Chemical Technology Series No. 264

摘要

The objective of this thesis was to study factors affecting the treatment211u001eefficiency in pulp and paper mills activated sludge plants. Another objective was 211u001eto develop a process monitoring system based on statistical multivariate methods. 211u001eA short review of activated sludge plants within pulp and paper industry and 211u001ebasic theory of multivariate data analysis is given at the beginning. The effects 211u001eof pulp and paper mill effluents and their treatment with the activated sludge 211u001eprocess are discussed in the first experimental part. The process and control 211u001eparameters of the process are studied in the next chapters. Effluent quality and 211u001esludge settling ability are studied with PLS (Partial Least Squares) models. The 211u001emain process parameters affecting each effluent quality parameter are selected 211u001eand the parameters were modeled separately. Lack of relevant information is 211u001ediscussed and a new monitoring parameter, ATP pool, is introduced. The objective 211u001eof this luminometric assay study is to provide an easy to measure quantity that 211u001ewould quickly give a sufficiently accurate estimate of the amount of biologically 211u001eactive sludge. The experimental data determined in laboratory and mill conditions 211u001eare presented. Finally, the prinicipal idea of a monitoring system is introduced 211u001eand evaluated by using experimental data measured at three pulp and paper mills. 211u001eThe goal is to develop a process monitoring system, that would detect the 211u001eaproaching process drift, e.g., bulking state, on its early stage and by this 211u001emanner enable right control actions in time.