Reduction of Ammonia, Hydrogen Sulfide, and Short‐Chain Fatty Acids Emission during the Sewage Sludge Composting

Abstract

The effect of mature compost (MC) used as a bulking agent on ammonia, hydrogen sulfide, and short-chain fatty acids emission reduction during sewage sludge (SS) composting process was studied in this paper. Three types of mixtures, single SS, SS þ wood chips (SS þ WC), and SS þ MC, were composted in a laboratory reactor. Among the different treatments, decrement rates of NH 3 emission (based on initial TN) from SS to SS þ MC and SS þ WC to SS þ MC were 63 and 59%, respectively. The H 2 S concentration ranged from 0.759 to 1.140 mg m À3 for SS, from 0.075 to 0.455 mg m À3 for SS þ WC, and from 0.075 to 0.425 mg m À3 for SS þ MC and the short-chain fatty acids (C 2 -C 5 ) concentration ranged from 0.10 to 1.00 ppm for SS, from 0.10 to 1.50 ppm for SS þ WC, and from 0.10 to 0.80 ppm for SS þ MC. In addition, the temperature apparently, as well as the thermophilic stage, was also elevated by bulking agent addition, especially by the MC addition. The denaturing gradient gel electrophoresis analysis indicated that there was more diversity of the bacterial community during the SS þ MC process. According to these results, MC was a suitable bulking agent for reduction ammonia, hydrogen sulfide, and short-chain fatty acids emission during the SS composting.

The effect of the composting time on the gaseous emissions and the compost stability in a full-scale sewage sludge composting plant

“…Comparing to what has been observed in other RS composting studies (Rosenfeld et al, 2004;Pagans et al, 2006), similar maximum concentrations were found when material temperature was nearly 60ºC, whereas similar minimum concentrations were measured when material temperature dropped to mesophilic conditions. On the other hand, for the curing phase of pile 2 -which was always in mesophilic conditions-the maximum and minimum values registered in the gaseous emissions were 20 ppmv and 0.5 ppmv, respectively, which are lower than what has been found in similar works (Rosenfeld et al, 2004;Chen and Xin-Wu, 2010). There is a great difference between the emission rates observed in piles 1 and 2, indicating that ammonia emission is dependent on material's temperature, what fits…”

Characterization of the Gaseous and Odour Emissions from the Composting of Conventional Sewage Sludge

“…However, [42] evaluated the OEFs of different substrates in a 300 L aerated pilot-scale reactor, reporting an OEF of 9.35 × 10 8 ou•Mg −1 DM-SS for SS composting and [24] obtained an OEF of 9.45 × 10 7 ou•Mg −1 DM-SS in a full-scale sewage sludge composting plant. For SS composting, different ranges of target pollutants and odour concentrations can be found in literature depending on the characteristics of the feedstocks or the composting process itself [43][44][45]. Figure 4 shows the daily odour emission rates (OER) obtained during the SS composting process, together with the average temperature of the reactor and the specific airflow.…”

Improving Soil Fertility and Nutrient Dynamics with Leachate Attributes from Sewage Sludge by Impoundment and Co‐Composting

“…Even though the application of sewage sludge in the farm land recycles the essential nutrients, their continuous direct application may result in accumulation of potential toxic elements. [23][24][25] Nonetheless, it is widely accepted that around 35-40% of sewage-sludge-derived-compost guaranteed for healthy soil conditioning and serving as economical fertilizer for selective plant species without risk of contamination. [26] Considering these two scenarios of sludge application in agriculture, it is imperative to assess the profound impact of transport of nutrients, as well as potential immobilization of toxic compounds from such recirculating leachate in the porous media due to the possible physicochemical interactions.…”

“…Even though the application of sewage sludge in the farm land recycles the essential nutrients, their continuous direct application may result in accumulation of potential toxic elements. [ 23–25 ] Nonetheless, it is widely accepted that around 35–40% of sewage‐sludge‐derived‐compost guaranteed for healthy soil conditioning and serving as economical fertilizer for selective plant species without risk of contamination. [ 26 ]…”