The Impact of Wood Ash and Green Liquor Dregs Application on Ca, Cu, Zn and Cd Contents in Bark and Wood of Norway Spruce

Abstract

To counteract nutrient depletion and acidification of forest soils, recycling of waste products from the forest industry has been suggested. Spreading of these waste products will probably change the concentration and availability of Ca and heavy metals in forest soils and thereby the contents of these metals in trees. This field study aimed at examining the influence of pellets of wood ash (ash) or a mixture of wood ash and green liquor dregs (ash+GLD) on the contents of Ca, Cd, Cu and Zn in wood and bark of Norway spruce [Picea abies (L.) Karst.]. The waste products were spread in an amount of 3000 kg ha −1 in 1996 at a felling site in Sweden and in 1999 and 2002 young spruce trees, planted in 1995, were collected and wood and bark were analysed for Ca, Cd, Cu and Zn with AAS. Changes in the metal content of wood and bark of young spruce trees were found 3 and 6 years after spreading pellets of ash or ash+GLD compared with the control. The effect of the treatments on the metal contents of bark and wood differed and was larger after 3 years than after 6 years. Treatment with ash+GLD tended to have less effect on the metal contents of bark and wood than treatment with only ash. An increase in the contents of Cu and Zn in bark or wood, compared with the control, was only found for the ash treatment and only 3 years after application. Both the ash and ash+GLD treatment decreased the Cd content of the wood and/or bark after 3 years, and after 6 years it still was, or tended to be, lower than the control.

Separation, treatment and utilization of inorganic residues of chemical pulp mills

“…The Na and K salts in pulp mill residues are easily soluble, while Ca and Mg salts have limited solubility (Mahmoudkhani et al, 2004). GLD and lime mud also contain heavy metal constituents such as Cd, Cu and Zn, which are hazardous to the environment ( € Osterås et al, 2005). In Finland, an environmental permit is required for the use of the residues from Kraft mills as forest fertilizers.…”

Amelioration of soil acidity by the application of maize straw ash in mixed soil

“…This might be because maize straw ash acted as a source of Mn. Increases in foliar Cu and Zn for biomass ash treatment have been reported by Osteras et al (2005). (24) .…”

“…Increases in foliar Cu and Zn for biomass ash treatment have been reported by Osteras et al (2005). (24) . Available zinc content of the soil changed into double after the wood ash treatment (25) .…”

Wastes from pulp and paper mills - a review of generation and recycling alternatives

“…Zambrano et al [50] showed that the physical and chemical characteristics of the waste are useful for plants, and the research confirmed their potential use on degraded soils in Chile. In Sweden, Österås et al [51] concluded that in a long-term perspective the use of such wastes does not increase the accumulation of heavy metals in plants. Lu et al [52] showed that the phytotoxicity is not a problem for land application in Taiwan.…”