基于水华风险控制的再生水景观水体水力停留时间阈值研究

再生水景观利用是解决城市景观用水短缺的有效途径之一。但较高氮磷浓度的再生水进入流动性较差的景观水体中极易发生水华现象。在现有再生水排放标准下，水力停留时间的调控是控制景观水体中微藻生物量的有效手段。根据微藻生长模型和水质动力学模型，提出了基于水力停留时间调控的景观水体水华控制方法及其阈值确定方法。通过计算，得到再生水氮、磷浓度执行GB 18918—2002《城镇污水处理厂污染物排放标准》A标准(总氮15 mg/L,总磷0.5 mg/L)对应的水力停留时间阈值为2.477 d;执行DB11/890—2012北京市《城镇污水处理厂水污染物排放标准》A(总氮10 mg/L,总磷0.2 mg/L)对应的水力停留时间阈值为5.034 d;执行昆明市地方标准DB5301/T43—2020《城镇污水处理厂主要污染物排放限值》A级(总氮5 mg/L,总磷0.05 mg/L)对应的水力停留时间阈值为21.659 d, B级(总氮10 mg/L,总磷0.3 mg/L)对应的水力停留时间阈值为3.783 d, C级(总氮15 mg/L,总磷0.4 mg/L)对应的水力停留时间阈值为2.811 d;执行91/...

REGULATION OF HYDRAULIC RETENTION TIME THRESHOLD OF RECLAIMED WATER LANDSCAPE FOR BLOOM CONTROL

Utilization of reclaimed water landscape is one of the effective ways to solve the shortage of urban landscape water. However, reclaimed water with a high concentration of nitrogen and phosphorus enters the landscape water with poor mobility, which is prone to water bloom. Under the existing reclaimed water discharge standard, the regulation of hydraulic retention time is an effective means to control microalgae biomass in landscape water. In this study, based on the microalgae growth model and the water quality dynamical model, a method for controlling the water bloom of landscape water and its threshold determination based on regulation of hydraulic retention time were proposed. Through calculation, the threshold value of hydraulic retention time corresponding to the national standard GB 18918-2002 (TN=15 mg/L, TP=0.5 mg/L) was 2.477 d; corresponding to the discharge standard (DB11/800-2012) level A (TN=10 mg/L, TP=0.2 mg/L) of water pollutants for urban sewage treatment plants in Beijing was 5.033 d; corresponding to the discharge standard (DB5301/T43-2020) level A of Kunming sewage treatment plants (TN=5 mg/L, TP=0.05 mg/L) was 21.655 d; corresponding to the discharge standard (DB5301/T43-2020) level B of Kunming sewage treatment plants (TN=10 mg/L, TP=0.3 mg/L) was 3.783 d; corresponding to the discharge standard (DB5301/T43-2020) level C of Kunming sewage treatment plants (TN=15 mg/L, TP=0.4 mg/L) was 2.811 d; corresponding to the standard of EU urban sewage treatment (91/271/ZEC) (TN=15 mg/L, TP=2 mg/L) was 1.475 d. If the hydraulic retention time of the landscape water body is less than the corresponding threshold, the water blooms in the landscape water body can be effectively controlled.