Transport and changes of emerging contaminants in the amended soils by organic wastes

As the costs of fossil fuel and inorganic fertiliser increases and availability declines, there is an increasing requirement to recycle nutrient-rich organic wastes to land, as fertilisers. However, organic materials can also... [ view full abstract ]

As the costs of fossil fuel and inorganic fertiliser increases and availability declines, there is an increasing requirement to recycle nutrient-rich organic wastes to land, as fertilisers. However, organic materials can also contain potentially toxic constituents, and so application of organic materials to land has the potential to increase levels of contaminants in soils and cause harm to the environment. Therefore, the objective of this work is to trace the changes of emerging contaminants (e.g. antibiotic resistance genes (ARGs) and endocrine disrupting compounds (EDCs)) in the agricultural soils amended by different organic wastes (sewage sludge, compost and manure). The field experiment was conducted at the James Hutton Institute research station at Glensaugh, Aberdeenshire, UK. The organic fertilizer, control and treated soil samples were collected for EDCs and ARGs analysis over time. The predicted environmental concentration (PEC, calculated by the chemical content in organic wastes and the treating rate) of EDCs in in treated soils showed as following order: Sludge>Compost>Manure. These trends are in agreement with the measured EDC concentration in the differently amended soils, which suggested that the organic wastes introduced the chemical and increased/accumulated the contaminants in the treated soils. In all treatments, the relative abundance of most ARGs detected decreased over time, especially IntI1 and tet ARGs. However, the multiple applications of organic fertilisers resulted in higher ARGs in comparison to inorganic fertiliser (NPK), either by a lesser decrease of IntI1 and tet ARG or an increase of sul ARG.