Wood Ashes from Grate-Fired Heat and Power Plants: Evaluation of Nutrient and Heavy Metal Contents
Ashes from biomass heat (and power) plants that apply untreated woody biofuels may be suitable for use as fertilizers if certain requirements regarding pollutant and nutrient contents are met. The aim of this study was to examine if both bottom and cyclone ashes from 17 Bavarian heating plants and o...
Main Authors: | , , |
---|---|
Format: | Article |
Language: | English |
Published: |
MDPI AG
2021-05-01
|
Series: | Sustainability |
Subjects: | |
Online Access: | https://www.mdpi.com/2071-1050/13/10/5482 |
id |
doaj-5eeeb0460b84435a840b41fccee5ef3e |
---|---|
record_format |
Article |
spelling |
doaj-5eeeb0460b84435a840b41fccee5ef3e2021-05-31T23:59:10ZengMDPI AGSustainability2071-10502021-05-01135482548210.3390/su13105482Wood Ashes from Grate-Fired Heat and Power Plants: Evaluation of Nutrient and Heavy Metal ContentsHans Bachmaier0Daniel Kuptz1Hans Hartmann2Technology and Support Centre in the Centre of Excellence for Renewable Resources (TFZ), Schulgasse 18, 94315 Straubing, GermanyTechnology and Support Centre in the Centre of Excellence for Renewable Resources (TFZ), Schulgasse 18, 94315 Straubing, GermanyTechnology and Support Centre in the Centre of Excellence for Renewable Resources (TFZ), Schulgasse 18, 94315 Straubing, GermanyAshes from biomass heat (and power) plants that apply untreated woody biofuels may be suitable for use as fertilizers if certain requirements regarding pollutant and nutrient contents are met. The aim of this study was to examine if both bottom and cyclone ashes from 17 Bavarian heating plants and one ash collection depot are suitable as fertilizers (<i>n</i> = 50). The range and average values of relevant nutrients and pollutants in the ashes were analyzed and evaluated for conformity with the German Fertilizer Ordinance (DüMV). Approximately 30% of the bottom ashes directly complied with the heavy metal limits of the Fertilizer Ordinance. The limits were exceeded for chromium(VI) (62%), cadmium (12%) and lead (4%). If chromium(VI) could be reduced by suitable treatment, 85% of the bottom ashes would comply with the required limit values. Cyclone ashes were high in cadmium, lead, and zinc. The analysis of the main nutrients showed high values for potassium and calcium in bottom ashes, but also relevant amounts of phosphorus, making them suitable as fertilizers if pollutant limits are met. Quality assurance systems should be applied at biomass heating plants to improve ash quality if wood ashes are used as fertilizers in agriculture.https://www.mdpi.com/2071-1050/13/10/5482wood ashfertilizerheat and power plantsheavy metalsnutrientsGerman fertilizer legislation |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Hans Bachmaier Daniel Kuptz Hans Hartmann |
spellingShingle |
Hans Bachmaier Daniel Kuptz Hans Hartmann Wood Ashes from Grate-Fired Heat and Power Plants: Evaluation of Nutrient and Heavy Metal Contents Sustainability wood ash fertilizer heat and power plants heavy metals nutrients German fertilizer legislation |
author_facet |
Hans Bachmaier Daniel Kuptz Hans Hartmann |
author_sort |
Hans Bachmaier |
title |
Wood Ashes from Grate-Fired Heat and Power Plants: Evaluation of Nutrient and Heavy Metal Contents |
title_short |
Wood Ashes from Grate-Fired Heat and Power Plants: Evaluation of Nutrient and Heavy Metal Contents |
title_full |
Wood Ashes from Grate-Fired Heat and Power Plants: Evaluation of Nutrient and Heavy Metal Contents |
title_fullStr |
Wood Ashes from Grate-Fired Heat and Power Plants: Evaluation of Nutrient and Heavy Metal Contents |
title_full_unstemmed |
Wood Ashes from Grate-Fired Heat and Power Plants: Evaluation of Nutrient and Heavy Metal Contents |
title_sort |
wood ashes from grate-fired heat and power plants: evaluation of nutrient and heavy metal contents |
publisher |
MDPI AG |
series |
Sustainability |
issn |
2071-1050 |
publishDate |
2021-05-01 |
description |
Ashes from biomass heat (and power) plants that apply untreated woody biofuels may be suitable for use as fertilizers if certain requirements regarding pollutant and nutrient contents are met. The aim of this study was to examine if both bottom and cyclone ashes from 17 Bavarian heating plants and one ash collection depot are suitable as fertilizers (<i>n</i> = 50). The range and average values of relevant nutrients and pollutants in the ashes were analyzed and evaluated for conformity with the German Fertilizer Ordinance (DüMV). Approximately 30% of the bottom ashes directly complied with the heavy metal limits of the Fertilizer Ordinance. The limits were exceeded for chromium(VI) (62%), cadmium (12%) and lead (4%). If chromium(VI) could be reduced by suitable treatment, 85% of the bottom ashes would comply with the required limit values. Cyclone ashes were high in cadmium, lead, and zinc. The analysis of the main nutrients showed high values for potassium and calcium in bottom ashes, but also relevant amounts of phosphorus, making them suitable as fertilizers if pollutant limits are met. Quality assurance systems should be applied at biomass heating plants to improve ash quality if wood ashes are used as fertilizers in agriculture. |
topic |
wood ash fertilizer heat and power plants heavy metals nutrients German fertilizer legislation |
url |
https://www.mdpi.com/2071-1050/13/10/5482 |
work_keys_str_mv |
AT hansbachmaier woodashesfromgratefiredheatandpowerplantsevaluationofnutrientandheavymetalcontents AT danielkuptz woodashesfromgratefiredheatandpowerplantsevaluationofnutrientandheavymetalcontents AT hanshartmann woodashesfromgratefiredheatandpowerplantsevaluationofnutrientandheavymetalcontents |
_version_ |
1721415993933168640 |