ION EXCHANGE IN THE TREATMENT OF CONCENTRATED WASTEWATER FROM DAIRY PLANTS WITH OBTAINING BIOLOGICALLY VALUABLE WASTE

Abstract

In this paper, research aimed to analyse the possibilities of ion exchange utilisation in the treatment of concentrated wastewater from dairy plants to obtain biologically valuable waste was conducted. It has been established that the ion exchange utilization has a complex effect on all components of the whey proteins  aggregation stability and ensures their extraction in the treatment processes. The results of the study showed that the highest values of phosphate and calcium ions removed are achieved by the sequential cationisation and anionisation technology under strongly acidic-oxidising environment - 99.1% and 94.7%, respectively. Moreover, this ion exchange technology and type of whey environment was found to have the highest change in total protein content, 84.6%. In order to analyse changes in the proteins aggregative stability in the ion exchange process, second-order potentiometric titration curves of the whey before and after ion exchange were drown, which characterise the relative changes in proteolytic equilibrium in the processes of concentrated dairy wastewater treatment. The results of the secondorder potentiometric titration curves analysis indicate that in the process of sequential cationisation and anionisation under a strongly acidic-oxidising environment, it is possible to ensure the extraction ofa product enriched with the protein fraction of α- lactalbumin in the amount of 70%, or approximately 1,26–1,6 kg/m3 and β-lactoglobulin in the amount of 65%, or approximately 2,93–3,25 kg/m3. The extracted proteins, together with phosphates and  calcium, can be obtained as eluates of a given composition as a biologically valuable waste product. Additionally, changes in the organic load (on centralised wastewater treatment systems) by COD in the process of whey ionisation (in local treatment cycles) were analysed. It was found that the level of organic load by COD decreases, particularly by 54.3%. This can provide the  following reduction in the consumption of expensive reagents in centralised wastewater treatment systems, as well as provide opportunities for the utilisation of traditional coagulation technologies for wastewater streams containing whey that were pre-treated locally by ion exchange. It is proposed to apply the obtained results in the further development of combined treatment schemes for the treatment of concentrated wastewaters from dairy plants with obtaining biologically valuable waste in the form of eluates of a given composition and residual whey with a reduced content of allergenic protein fractions.