Abstract

Presence of organic compounds from cosmetics, detergents or pharmaceuticals found in wastewater is mainly a consequence of human activity. In wastewater treatment plants (WWTPs) removal of these pollutants takes place as secondary treatment in the aeration tank. An important parameter in this treatment is hydraulic retention time, which represents the treatment period in the aeration tank, recommended for most systems of 4 to 8 h. Also, several mathematical models were developed to determine the fate and removal efficiency of organic compounds in WWTPs. One of the most used is the SimpleTreat model (“9-box” model) which was created by the National Institute of Public Health and Environment in Netherlands (RIVM). The model considers 9 compartments or boxes in which the primary settler, aeration tank and secondary clarifier of a WWTP are contained separately. Each basin has a liquid (water) and a solid phase (suspended solids) in which the pollutant may be dissolved and/or adsorbed, respectively. Estimations of the organic compound concentration values may be determined in each WWTP basin and also discharged via effluent. All values are expressed in percentage from compound nominal concentration in influent representing the removal efficiency. This study presents estimations with the SimpleTreat model of the removal efficiency of six organic compounds found in products as: cosmetics—Tonalide (AHTN), decamethylcyclopentasiloxane (D5) and edetic acid (EDTA); detergents—benzalkonium chloride (BAC) and pharmaceuticals—Permethrin (PMT) and Atenolol (A). Depending on their chemical properties, these compounds may be found in influent mostly dissolved in the liquid phase or mostly adsorbed on the surface of the suspended solids. The removal efficiency is evaluated after 2, 5, and 10 h of retention in the aeration tank.

中文翻译：

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水力停留时间对废水中有机污染物去除的影响

摘要

在废水中发现的来自化妆品、洗涤剂或药物的有机化合物主要是人类活动的结果。在污水处理厂 (WWTP) 中，这些污染物的去除在曝气池中作为二级处理进行。该处理中的一个重要参数是水力停留时间，它代表曝气池中的处理时间，建议大多数系统为 4 到 8 小时。此外，还开发了几个数学模型来确定污水处理厂中有机化合物的归宿和去除效率。最常用的模型之一是荷兰国家公共卫生与环境研究所 (RIVM) 创建的 SimpleTreat 模型（“9 盒”模型）。该模型考虑了 9 个隔间或盒子，其中主要定居者，污水处理厂的曝气池和二沉池是分开的。每个盆地具有液体（水）和固相（悬浮固体），其中污染物可以分别溶解和/或吸附。可以在每个 WWTP 流域中确定有机化合物浓度值的估计值，也可以通过污水排放。所有值均以代表去除效率的进水化合物标称浓度的百分比表示。本研究使用 SimpleTreat 模型对产品中发现的六种有机化合物的去除效率进行了估计，这些有机化合物包括：化妆品 — Tonalide (AHTN)、十甲基环五硅氧烷 (D5) 和依地酸 (EDTA)；洗涤剂——苯扎氯铵 (BAC) 和药物——氯菊酯 (PMT) 和阿替洛尔 (A)。根据它们的化学性质，这些化合物可能存在于进水中，大部分溶解在液相中或大部分吸附在悬浮固体的表面上。在曝气池中停留 2、5 和 10 小时后评估去除效率。