Monitoring of biopile composting of oily sludge

Abstract

This paper describes a bioreactor set-up used to simulate degradation of petroleum hydrocarbons in a static biopile. The largescale test was performed in a 28 m 3 custom-designed reactor. Oily sludge (40% by weight, having 7% dry matter [DM], and hydrocarbons C 10 -C 40 160,000 mg kg -1 DM) was mixed with organic-rich amendments -mature oil-compost (40%) and garden waste compost (20%). Within the reactor, the temperature and soil gases were monitored continuously during 370 days via 24 measurement points. Also, moisture content was continuously recorded and airflow through compost mix occasionally measured. Three-dimensional ordinary kriging spatial models were created to describe the dynamic variations of temperature, air distribution, and hydrocarbon concentration. There were large temperature differences in horizontal and vertical sections during initial months of composting only. Water content of the mixture was uneven by layers, referring on relocation of moisture due to aeration and condensation. The air distribution through the whole reactor varied largely despite of continuous aeration, while the concentration of O 2 was never reduced less than 1-2% on average. The results showed that composting of sludge using force-aerated static biopile technology was justified during the first 3-4 months, after which the masses could be re-mixed and heaped for further maturation in low-tech compost windrows. After 370 days of treatment, the content of hydrocarbons (C 10 -C 40 ) in the compost mixture was reduced by 68.7%.

Ex-Situ Remediation Technologies for Environmental Pollutants: A Critical Perspective

“…When a 27 m 3 biopile was operated for 22 weeks, it was able to remove 80 % TPH at full-scale (Iturbe et al 2007 ). A 28 m 3 pneumatically-aerated bioreactor set up in static biopile amended with manure oil compost (40 %) and garden waste compost (20 %) successfully removed 68.7 % petroleum hydrocarbons within 3-4 months treatment time (Kriipsalu and Nammari 2010 ). Seabra et al ( 2006 ) demonstrated that it was possible to remediate even crude oil-contaminated clayey soils (39,442 mg/kg TPH concentration) to acceptable levels by rice hull amendments and periodic pile mixings within 16 weeks.…”

The Characteristics of Shallow Groundwater in Petroleum Contaminated Site and the Assessment of Efficiency of Biopile by Off-gas Analysis

“…계에 심각한 영향을 준다 (Jo et al, 2010 (Coulon et al, 2010;Lin et al, 2010;Kriipsalu and Nammari, 2010;Beškoski et al, 2011;Wang et al, 2012 …”

Bioremediation of clayey soil contaminated with crude oil: comparison of dynamic and static biopiles in lab-scale

“…The main difference relates to the aeration system. In static biopile, aeration is forced through a net of perforated pipes installed on the bottom, connected to a blower, vacuum pump or an exhaust-driven wind (Jorgensen al., 2000;Li et al, 2004;Kriipsalu, et al 2009). In dynamic biopile, aeration is achieved through periodic soil tillage, similar to the procedure applied to the composting windrows (Lopes, et al, 2011).…”

“…To use this type of biopile one needs to move machinery and equipment more intensively (Lopes et al, 2011). The main restriction regarding static biopiles is uneven spatial distribution of heat, moisture and therefore the ideal conditions for microbial activity within the soil mass does not occur evenly, creating hotspots where contamination persists (Kriipsalu et al 2009). Indeed, the forced ventilation enhances losses of water and heat inside the biopiles (Kodres, 1998, Li et al 2004Kriipsalu al.…”