The inadequate removal of pharmaceuticals and other micropollutants in municipal wastewater treatment plants, as evidenced by their detection of these substances in the aquatic environment has led to the need for sustainable remediation strategies. Laccases possess a number of advantages including a broad substrate spectrum. To identify promoting or inhibitory effects of reaction partners in the remediation processes we tested not only single compounds—as has been described in most studies—but also mixtures of pollutants. The reaction of diclofenac (DCF) and flufenamic acid (FA), mediated by Trametes versicolor laccase resulted in the formation of products, which were more hydrophilic than the respective reactant (reactant concentration of 0.1 mM; laccase activity 0.5 U/ml). Analyses (HPLC, LC/MS) showed that the product 1a and 1b for DCF and FA, respectively, to be a para-benzoquinone imine derivative. The formation of 1a was enhanced by the addition of bisphenol A (BPA). After 6 days 97% more product was formed in the mixture of DCF and BPA compared with DCF tested alone. Product 1a was also detected in experiments with micropollutant-supplemented secondary effluent. Within 24 h 67% and 100% of DCF and BPA were transformed, respectively (25 U/ml). Experiments with a membrane reactor (volume 10 l; phosphate buffer, pH 7) were in good agreement with the results of the laboratory scale experiments (50 ml). EC50-values were also determined. The data support the use of laccases for the removal or detoxification of recalcitrant pollutants. Thus, the enzyme laccase may be a component of an additional environmentally friendly process for the treatment stage of wastewater remediation.
城市污
水处理厂对药物和其他微污染物的去除效果不佳,
水生环境中检测到这些物质就是证明,因此需要制定可持续的补救策略。
乳酸菌酶具有多种优势,包括广泛的底物谱。为了确定反应伙伴在修复过程中的促进或抑制作用,我们不仅测试了单一化合物(大多数研究中都有描述),还测试了污染物混合物。
双氯芬酸(DCF)和
氟非那酸(FA)在
金龟子
漆酶的介导下发生反应,生成的产物比相应的反应物更具亲
水性(反应物浓度为 0.1 mM;
漆酶活性为 0.5 U/ml )。分析(HPLC、LC/MS)表明,DCF 和 FA 的产物 1a 和 1b 分别是
对苯醌亚胺衍
生物。加入双
酚 A(
BPA)后,1a 的生成量增加。6 天后,在 DCF 和
BPA 的混合物中形成的产物比单独测试 DCF 多 97%。在使用添加了微量污染物的二级污
水的实验中也检测到了产物 1a。在 24 小时内,分别有 67% 和 100% 的 DCF 和
BPA 被转化(25 U/ml)。使用膜反应器(容积 10 升;
磷酸盐缓冲液,pH 值 7)进行的实验与实验室规模实验(50 毫升)的结果非常吻合。同时还测定了
EC50 值。这些数据支持使用
漆酶去除或解毒难降解的污染物。因此,
漆酶可以成为废
水处理阶段的另一种环境友好型工艺的组成部分。