实验室甲醛废液处理

Treatment of Formaldehyde-Polluted Wastewater from Laboratories

根据尿素与甲醛缩合原理与活性炭吸附原理，采用尿素缩合法与活性炭吸附法处理模拟甲醛废液，比较两方法的可行性与经济性后，最终选择尿素缩合法为处理方案，并用实验室实际废液验证该方法。通过正交实验，研究了尿素用量、反应温度以及反应时间与甲醛去除率的关系。结果表明，在pH=2．0，100mL模拟甲醛废液（浓度约为1g／L）中加入8．0g尿素，在30℃的条件下，静置40min进行缩合处理，模拟甲醛废液浓度降至2μg／L，远低于到国家一级排放标准（1．0mg／L），最终去除率可达到99．99％。用此方案处理实验室的实际甲醛废液，检测结果为去除率达到99．99％以上，残余浓度为3．0～5．0mg／L，符合国家排放标准（5．0mg／L）。

Based on the principle of degrading formaldehyde by urea and the principle of adsorption by activated carbon, the two methods, urea degradation and activated carbon adsorption, were compared on feasibility and economy. The first method was adopted and testified using laboratory wastewater. The effects of urea mass, temperature and reaction time on formaldehyde removal rate in simulated wastewater were studied by orthogonal experiments. Best removal rate （99.99 % ） for treatment of 100 mL wastewater （containing 1 g formaldehyde） is acquired at pH 4.0 -4.5, activated carbon 12 g, degraded for 40 minutes at 25 ℃, with the final concentration at 2 μg/L, complying with national top standard for discharge（ 1.0 mg/L）. When applied into laboratory wastewater, formaldehyde is removed by 99.99% , with residue of 3.0 -5.0 mg/L, reaching national discharge standard （5.0 mg/L）.