Virginia Tech, Blacksburg, Virginia, USA.
Hampton Roads Sanitation District, Virginia Beach, Virginia, USA.
Water Environ Res. 2024 Aug;96(8):e11108. doi: 10.1002/wer.11108.
1,4-Dioxane is a probable human carcinogen and a persistent aquatic contaminant. Cometabolic biodegradation of 1,4-dioxane is a promising low-cost and effective treatment technology; however, further demonstration is needed for treating landfill leachate. This technology was tested in two full-scale moving bed biofilm reactors (MBBRs) treating raw landfill leachate with tetrahydrofuran selected as the cometabolite. The raw leachate contained on average 82 μg/L of 1,4-dioxane and before testing the MBBRs removed an average of 38% and 42% of 1,4-dioxane, respectively. First, tetrahydrofuran was added to MBBR 1, and 1,4-dioxane removal was improved to an average of 73%, with the control MBBR removing an average of 37% of 1,4-dioxane. During this period, an optimal dose of 2 mg/L of tetrahydrofuran was identified. Tetrahydrofuran was then fed to both MBBRs, where the 1,4-dioxane removal was on average 73% and 80%. Cometabolic treatment at the landfill significantly reduced the concentration of 1,4-dioxane received from the landfill at a downstream wastewater treatment and indirect potable reuse facility, reducing the load of 1,4-dioxane from 44% to 24% after the study. PRACTITIONER POINTS: Cometabolic degradation of leachate 1,4-dioxane with THF in MBBRs is a feasible treatment technology and a low-cost technique when retrofitting existing biological treatment facilities. The MBBRs can be operated at a range of temperatures, require no operational changes beyond THF addition, and operate best at a mass ratio of THF to 1,4-dioxane of 24. Source control of 1,4-dioxane significantly reduces the concentration of 1,4-dioxane in downstream wastewater treatment plants and potable reuse facilities.
1,4-二恶烷是一种可能的人类致癌物和持久性水生污染物。共代谢生物降解 1,4-二恶烷是一种很有前途的低成本、有效处理技术；然而，对于处理垃圾渗滤液还需要进一步的论证。该技术在两个全规模移动床生物膜反应器（MBBR）中进行了测试，以四氢呋喃作为共代谢物处理原始垃圾渗滤液。原始渗滤液中平均含有 82μg/L 的 1,4-二恶烷，在测试 MBBR 之前，分别平均去除了 38%和 42%的 1,4-二恶烷。首先，将四氢呋喃添加到 MBBR1 中，1,4-二恶烷去除率提高到平均 73%，而对照 MBBR 平均去除 1,4-二恶烷的 37%。在此期间，确定了最佳剂量为 2mg/L 的四氢呋喃。然后将四氢呋喃供给两个 MBBR，1,4-二恶烷的去除率平均为 73%和 80%。在垃圾填埋场进行共代谢处理后，显著降低了下游废水处理和间接饮用水再利用设施中从垃圾填埋场接收的 1,4-二恶烷浓度，研究后将 1,4-二恶烷的负荷从 44%降低到 24%。实践要点：在 MBBR 中使用 THF 共代谢降解渗滤液中的 1,4-二恶烷是一种可行的处理技术，也是改造现有生物处理设施的低成本技术。MBBR 可以在一定温度范围内运行，除添加 THF 外无需进行任何操作更改，最佳 THF 与 1,4-二恶烷的质量比为 24。1,4-二恶烷的源头控制显著降低了下游废水处理厂和饮用水再利用设施中 1,4-二恶烷的浓度。
