Department of Chemistry, Tongji University, 1239 Siping Road, Shanghai 200092, PR China.
J Hazard Mater. 2013 Oct 15;261:63-71. doi: 10.1016/j.jhazmat.2013.07.002. Epub 2013 Jul 10.
We attempted catalytic wet air oxidation (CWAO) of nanofiltration (NF)-reject using Pd based catalyst viz., Pd/activated charcoal (AC) and PdCl2 with the objective of degradation of refractory organic pollutants. Refractory organic pollutants in NF-reject before and after WAO and CWAO were confirmed by GC-MS analysis. Experiments were conducted to investigate the effects of temperature, catalyst dosage and air partial pressure on the rate of removal of total organic carbon (TOC). The reaction kinetics can be conveniently described by considering two-stage first order kinetics. The use of Pd/AC afforded 85% TOC removal, the corresponding rate constant (k) was 2.90 ± 0.075 × 10(-3)min(-1) (Pd/AC, 100mg/L; T, 473.15K; Pair, 0.69 MPa). On the other hand, 75% TOC was removed with k=2.31 ± 0.075 × 10(-3)min(-1) using Pd(2+) catalyst (Pd(2+), 16.66 mg/L; T, 473.15K; Pair, 0.69 MPa). The observed rate of mineralization under Pd-catalyzed conditions was significantly higher than that of the uncatalyzed oxidation (41%) under the similar experimental conditions. Catalyst stability experiments were performed and TEM, SEM, XRD, Raman and XPS characterization data collected. Despite some morphological transformation of support, Pd catalyst was stable under CWAO conditions.
我们尝试使用钯基催化剂（即 Pd/活性炭（AC）和 PdCl2）进行纳滤（NF）反渗透液的催化湿式空气氧化（CWAO），以降解难处理的有机污染物。WAO 和 CWAO 前后 NF 反渗透液中的难处理有机污染物通过 GC-MS 分析得到确认。实验研究了温度、催化剂用量和空气分压对总有机碳（TOC）去除率的影响。通过考虑两段一级动力学，可以方便地描述反应动力学。使用 Pd/AC 可达到 85%的 TOC 去除率，相应的速率常数（k）为 2.90±0.075×10(-3)min(-1)（Pd/AC，100mg/L；T，473.15K；Pair，0.69 MPa）。另一方面，使用 Pd(2+)催化剂（Pd(2+)，16.66mg/L；T，473.15K；Pair，0.69 MPa）可去除 75%的 TOC，k=2.31±0.075×10(-3)min(-1)。在 Pd 催化条件下观察到的矿化率明显高于相似实验条件下无催化氧化（41%）的矿化率。进行了催化剂稳定性实验，并收集了 TEM、SEM、XRD、拉曼和 XPS 特征数据。尽管载体存在一些形态转化，但 Pd 催化剂在 CWAO 条件下稳定。
