The Effect of Mineral-Based Mixtures Containing Coal Fly Ash and Sewage Sludge on Chlorophyll Fluorescence and Selected Morphological Parameters of Deciduous and Coniferous Trees

Abstract

Coal fly ash (CFA), which is generated in huge quantities in coal-fired power plants, is a problem worldwide. Mixtures with ash and sewage sludge alter morphological and biochemical characteristics of plants. In this experiment, the response of pine, spruce, beech and alder growing for four years to mineral mixtures based on coal fly ash and high salinity sewage sludge (SS) was studied. The four-year experiment determined the chlorophyll a fluorescence of the tested plants, their height and yield, the salinity level of the tested mixtures and their phytotoxicity. Mixtures of coal ash with sewage sludge proved to be more beneficial to plants than their separate application. After four years, among the studied species, the highest increase in height and biomass was recorded for European alder and Scots pine. These species were also characterized by high photosynthetic indices. Mixtures containing 29% SS created optimal conditions for the development of the studied tree species. Grey alder and ponderosa pine can be recommended for reclamation of degraded areas where CFA and SS mixtures are used.