Kasemsap Charuvan, Wantawin Chalermraj
The Joint Graduate School of Energy and Environment, King Mongkut's University of Technology Thonburi, Bangkok 10140, Thailand.
Bioresour Technol. 2007 Mar;98(5):1020-7. doi: 10.1016/j.biortech.2006.04.035. Epub 2006 Jun 21.
Polyhydroxyalkanoate (PHA), a biodegradable plastic, can be produced from excess activated sludge by utilizing intracellular glycogen and polyphosphate as energy sources under growth-limiting conditions. Activated sludge of 2%, 6%, and 8% polyphosphate with similar glycogen content of 33% was investigated for batch PHA production by varying the pH values from 6 to 8. Acetate applied at 1000 mg COD/L was almost exhausted within 80 min of anaerobic stage. The remaining glycogen in the sludge was higher at a lower pH because of less energy used for acetate uptake. Highest PHA content of 51% was obtained from sludge with an 8% polyphosphate content at pH 8. PHA production occurred rapidly within the first 20 min, with a productivity rate of 2.19 g PHA/L-h. The results in this study indicate that PHA production by using activated sludge is a promising alternative to a typical pure culture approach.
聚羟基脂肪酸酯（PHA）是一种可生物降解的塑料，在生长受限条件下，利用细胞内糖原和聚磷酸盐作为能源，可从过量活性污泥中生产得到。研究了聚磷酸盐含量分别为2%、6%和8%且糖原含量相似（均为33%）的活性污泥，通过将pH值从6变化到8来进行PHA的分批生产。在厌氧阶段80分钟内，以1000 mg COD/L施加的乙酸盐几乎耗尽。由于用于乙酸盐摄取的能量较少，较低pH值下污泥中剩余的糖原含量较高。在pH值为8时，从聚磷酸盐含量为8%的污泥中获得了最高51%的PHA含量。PHA在前20分钟内快速产生，生产率为2.19 g PHA/L·h。本研究结果表明，利用活性污泥生产PHA是一种很有前景的替代典型纯培养方法的途径。
