Preliminary study of diesel biodegradation mechanism in the food waste composting process

1. 2012 International Conference on Environmental Quality Concern, Control and Conservation (EQC 2012) Preliminary study of diesel biodegradation mechanism in the food waste composting process Li-Hsien Chen1, Guan-Yu Chen1, Guo-Huei Wang1, Der-Shyan Sheu2, Chitsan Lin1 1 Department of Marine Environmental Engineering, National Kaohsiung Marine University. 2 Department of Marine Biotechnology, National Kaohsiung Marine University. Email: acermarcor@yahoo.com.tw 1 1 May 25-26, 2012

2. OUTLINE Research Background And Motivation Research Purposes Materials And Methods Results And Discussion Conclusions 2

3. Research Background • Oil pollution is a serious environmental problem in the past decades. According to the Taiwan EPA, there are 67 documented oil-related remediation sites in Kaohsiung. Source: Taiwan EPA (http://edw.epa.gov.tw/querySoilSite.aspx) 其中又以高雄市最為嚴重

4. Lin et al. (2012) reported an innovative mineral oil treatment technology. The other report that utilizing food waste thermophilic composting process to degrade 7,000 mg/kg of diesel contaminated soil in a scale of 10 tons. the diesel removal rate reached 90 % on Day 54. • The method has the following advantages: 1 2 3 4

5. Research Motivation • Food waste composting processes to degrade diesel will produce the intermediate VOCs (Volatile Organic Compounds), while VOCs with the composting process, resulting in different types of compounds. • However, we still don’t know mechanism. If we know the mechanism, then we can control the VOCs from compost.

6. Research Purposes • This study was divided into two parts: （A）The VOCs of food waste composting process by GC / MSD analysis • Use of the airbags sampling with GC / MS analysis. • Features: analysis of 101 kinds of voc compoundsat one time. （B） Exploring the diesel oil biodegradation mechanism in the food waste composting process.。 6

7. Materials And Methods

8. Experimental Framework VOC sample collection Food waste 70kg Analysis Compost pile sawdust 15kg Discussion Basic parameters monitoring mature compost 15kg Temperature pH Experimental pile Control pile Moisture content Oxygen content Add 1kgdiesel

9. Compost Operational Procedures Mixed Collection pool Crusher Machine Food waste weighing 70 kg was shredded to 1-cm particles. After mixed with 15 kg of sawdust (15%, w/w) and 15 kg of mature compost (15%, w/w). Water was added to maintain 50-60% moisture content. Temperature, moisture content,and pH were monitored during composting process.

10. Soil Gas Sampling Design Compost, Sampling tube • 在採樣前一天在堆肥內埋入採樣管。 • 利用Pump使負壓箱呈負壓狀態。 • 使堆肥氣體由外向採氣袋內部補充。

11. Sampling setup

12. Analysis Equipment

13. Analytical instruments Entech 7032 Auto sample Entech 7100 Cryogenic preconcentration Agilent 5975 MSD Agilent 7890 GAS Chromatography (GC)

14. Results And Discussion

15. The all VOCs of food waste composting processes to degrade diesel table

16. Total VOCschange during the compost process Temperature Rising Stage Thermophilic Stage Temperature Recovering Stage The initial of the composting produces the highest VOCs conc. , after rising stage shows a slow downward trend.

17. The VOCsof scaleduringTemperature Rising andThermophilic Stage (1)Bio-voc (2)Ketones (3)Aromatics ThermophilicStage Temperature Rising Stage (4)Cycloalkanes (5)Alkene (4)Alkanes (5)Amines (6)Sulfur • 高溫醱酵期溫度約維持20天左右，顯示添加柴油亦不會影響廚餘堆肥化程序之正常演進，亦證明本技術之可行性。

18. The composition of initial compost gases includes alkanes, alkene, naphthenic class, and the aromatics. The main source of VOCs at this stage is from low molecule weight compounds within the diesel constituents. During the diesel composting process (day 0 to day 8), bio-VOCs were observed all the time; these include 1R-.alpha.-pinene, beta.-pinene and D-limonene. After 1 day composting, the compost gas consists of alcoholsand carbonate ester. The contribution of alcohols and carbonate ester may be from the fermentation of more biodegradable food waste or alkanes in the diesel. The VOCs groups changes of food waste composting processes to degrade diesel On the 3th day, the compost gas emerges of thermophilicfermentation products these include ketones , aldehydes and sulfides. They may be from the alcohols and carbonate ester. Thermophilic Stage Thermophilic Stage Rising Rising Total Vocs conc. （ppm） Time （day） Time （day）

19. The VOCs compounds changes of food waste composting processes to degrade diesel Rising Thermophilic Stage Rising Thermophilic Stage After 1 day composting, the compost gas consists of Ethyl acetate and Ethyl alcohol. the compost gas emerges of thermophilic fermentation products these include Butannal, 3-methyl、2-Butanone. D-Limonene is the highest concentration of compound of BIO-VOC The composition of initial compounds is n-Octane、Methyl-cyclohexaneand Toluene Dimethyl sulfideis the most common compounds in the composting process. 負壓抽氣方式則能兼具有完熟時間短、控制臭味逸散 及操作成本大幅降低之優點。（張定生，2003 ）

20. The preliminary mechanismof diesel biodegradation • According to the above finding, we assume the mechanism as follows.

21. Conclusions

22. (1) (2) (3)

23. (4) (5) (6)

24. 簡報結束~ Thanks for your attention