Tag Archives: sewage sludge compost

696-707 E. Haiba, L. Nei, K. Herodes, M. Ivask and M. Lillenberg
On the degradation of metformin and carbamazepine residues in sewage sludge compost
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On the degradation of metformin and carbamazepine residues in sewage sludge compost

E. Haiba¹, L. Nei¹*, K. Herodes², M. Ivask¹ and M. Lillenberg³

¹University of Technology, Tartu College, Puiestee 78, EE51008 Tartu, Estonia
²University of Tartu, Institute of Chemistry, Ravila 14A, EE51010 Tartu, Estonia
³Estonian University of Life Sciences, Kreutzwaldi 58A, EE51014 Tartu, Estonia
*Correspondence: lembit.nei@ttu.ee

Abstract:

Recent decades have shown intensive studies devoted to the fate of pharmaceuticals in the environment. These studies have involved the development of analytical tools, determination of pharmaceuticals in different compartments, composting technologies, and plant uptake of pharmaceuticals. The presence of organic pollutants in sewage sludge, including pharmaceuticals, is a problem of major concern. The re-use of sewage sludge should be encouraged since it represents a long-term solution provided that the quality of the sludge re-used is compatible with public health and environmental protection requirements. Composting is a widely recognized way of making the soil application of sewage sludge safer.
In this study, the impact of sewage sludge composting on the degradation of metformin (MET), by far the most often prescribed antidiabetic drug worldwide, and carbamazepine (CBZ), a poorly biodegradable but widely used as an anticonvulsant drug to cure depression and seizures, were analysed. The anaerobically digested and dewatered sewage sludge samples were collected from municipal wastewater treatment plant. Composting experiments were performed under fixed conditions during 30 days. The results of the experiment showed that during a 1-month composting period more than 90% of MET residues degraded, but no degradation of CBZ took place during the composting period. The half-life of MET was 3 days for the compost mixture with the ratios of 1:3 and 1:2 (v:v). The results of this study show that composting maylead to the efficient degradation of MET, whereas for the elimination of CBZ from sewage sludge different means should be used.

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395–405 E. Haiba, L. Nei,, S. Kutti, M. Lillenberg, K. Herodes, M. Ivask, K. Kipper, R. Aro and A. Laaniste
Degradation of diclofenac and triclosan residues in sewage sludge compost
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Degradation of diclofenac and triclosan residues in sewage sludge compost

E. Haiba¹, L. Nei¹,*, S. Kutti¹, M. Lillenberg², K. Herodes³, M. Ivask¹, K. Kipper³, R. Aro³ and A. Laaniste³

¹ Tartu College, Tallinn University of Technology, Puiestee 78, EE51008 Tartu, Estonia
² Estonian University of Life Sciences, Kreutzwaldi 58A, EE51014 Tartu, Estonia
³ Institute of Chemistry, University of Tartu, Ravila 14A, EE51010 Tartu, Estonia
*Correspondence: lembit.nei@ttu.ee

Abstract:

Land application of sewage sludge compost is an important and efficient tool in the remediation of industrial landscapes and agricultural soils in Estonia. A number of studies have shown that, as a rule, pharmaceuticals and personal care products (PPCPs) are neither completely removed by sewage treatment, nor completely degraded in the environment. In this study, degradation rates of diclofenac sodium (DFC) and triclosan (TCS) were determined during sewage sludge composting. Anaerobically digested and dewatered sewage sludge was mixed with sawdust at two different ratios (1:2 and 1:3 sludge/sawdust, v:v). Then aerobic composting was carried out. These ratios were chosen on the basis of previous studies on sewage sludge composting with different bulking agents. The initial concentration of DFC and TCS was 2 mg kg-1 in relation to dry weight (dw). Low quantities of the studied pharmaceuticals were present in sewage sludge that was used for preparing the compost mixtures used in our experiments. The background concentrations of DFC and TCS were never equal to zero. The results showed that the difference between sewage sludge and bulking agent ratios (1:2 vs 1:3) in compost samples did not significantly affect temperature profiles during the experiment. The degradation of pharmaceuticals was more complete in the compost samples where the ratio of bulking agent was higher (1:3 by volume). The average degradation level (in all compost mixtures) was 95% for DFC and 68% for TCS. Pharmaceuticals entering into the soil may affect microbial activity, plant growth and development, and may have adverse effects on living organisms.

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