Evaluation of the impact of digestate formed during biogas production on the content of heavy metals in soil

Abstract

Article history: Received: February 2015 Received in the revised form: April 2015 Accepted: April 2015 The aim of the study was to identify and assess the impact of four diges- tive masses obtained from different organic substrates on the content of heavy metals in soil. The study utilized soil derived from fertilizer and equipment. Timothy grass was used as a test plant. The effect of a fertilizer on the analyzed mass was compared with the objects of reference, which were: a control object (without fertilization), fertilized objects with the use of ammonium nitrate, fresh pig slurry and mineral fertilizer YaraMila. Experiment was conducted in quadruplicate, consist- ing of the total of 76 objects. Based on the survey, it was found that the use of digestive for fertilizing purposes is justified because of its impact on various soil parameters and is comparable to the impact of traditional fertilizers such as manure, ammonium nitrate and mineral compound fertilizers. The use of the digestive did not cause greater accumulation of heavy metals in the soil, than it is in case of the use of ammonium nitrate fertilizer or fresh manure, which further confirms that these products are safe and can be applied alternatively with traditional fertilizers.