Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
J Environ Sci (China). 2012;24(12):2060-7. doi: 10.1016/s1001-0742(11)60998-4.
A microwave-H2O2 process for sludge pretreatment exhibited high efficiencies of releasing organics, nitrogen, and phosphorus, but large quantities of H2O2 residues were detected. A uniform design method was thus employed in this study to further optimize H2O2 dosage by investigating effects of pH and H2O2 dosage on the amount of H2O2 residue and releases of organics, nitrogen, and phosphorus. A regression model was established with pH and H2O2 dosage as the independent variables, and H2O2 residue and releases of organics, nitrogen, and phosphorus as the dependent variables. In the optimized microwave-H2O2 process, the pH value of the sludge was firstly adjusted to 11.0, then the sludge was heated to 80 degrees C and H2O2 was dosed at a H2O2:mixed liquor suspended solids (MLSS) ratio of 0.2, and the sludge was finally heated to 100 degrees C by microwave irradiation. Compared to the microwave-H2O2 process without optimization, the H2O2 dosage and the utilization rate of H2O2 in the optimized microwave-H2O2 process were reduced by 80% and greatly improved by 3.87 times, respectively, when the H2O2:MLSS dosage ratio was decreased from 1.0 to 0.2, resulting in nearly the same release rate of soluble chemical oxygen demand in the microwave-H2O2 process without optimization at H2O2:MLSS ratio of 0.5.
一种微波-H2O2 污泥预处理工艺具有高效释放有机物、氮和磷的特点，但检测到大量的 H2O2 残留。因此，本研究采用均匀设计方法，通过考察 pH 值和 H2O2 用量对 H2O2 残留量和有机物、氮和磷释放量的影响，进一步优化 H2O2 用量。建立了以 pH 值和 H2O2 用量为自变量，H2O2 残留量和有机物、氮和磷释放量为因变量的回归模型。在优化的微波-H2O2 工艺中，首先将污泥的 pH 值调节至 11.0，然后将污泥加热至 80°C，并以 H2O2:混合液悬浮固体（MLSS）比 0.2 的比例投加 H2O2，最后通过微波辐射将污泥加热至 100°C。与未经优化的微波-H2O2 工艺相比，当 H2O2:MLSS 比值从 1.0 降低到 0.2 时，优化的微波-H2O2 工艺中 H2O2 的用量和 H2O2 的利用率分别降低了 80%和提高了 3.87 倍，当 H2O2:MLSS 比值为 0.5 时，微波-H2O2 工艺中可溶性化学需氧量的释放率几乎相同。
