Ifeanyichukwu Edeh
The need to ensure that biodiesel have comparative advantage over the conventional diesel is probably responsible for the quest to reduce the cost of feedstock by investigating lipids from waste biological source like activated sludge. Usually, lipids are analysed using instruments such as gas chromatography (GC) and high performance liquid chromatography (HPLC). Unfortunately, these instruments are very expensive and are scarcely available in the developing countries. Thus, the current investigation was geared towards developing a method for the use of thin layer chromatography in determining the lipid composition in activated sludge. Upon optimization of the operating parameters, the results show that chloroform/methanol were good lipid carrier solvents, lipids were most visible using a destructive method with 5 % sulphuric acid in ethanol at 180 oC for 10 min. Petroleum ether/diethyl ether/acetic acid (80/20/1, v/v/v) and chloroform/methanol/28 % ammonia (65/25/5, v/v/v) impacted appreciably on the separation of neutral and phospholipids, respectively and plates activation was necessary for effective lipid separation. The neutral lipid classes identified were sterol, wax ester, acylglycerol, fatty acid, and the phospholipids were phosphatidylethanolamine, phosphatidylcholine, phosphatidylinositol and lysophosphatidylcholine. With this method, the lipid in activated sludge can easily be profiled, indicating a great potential for biodiesel, renewable diesel and oleochemical production.
Activated Sludge; Lipid; Thin Layer Chromatography; Extraction; Oleochemicals