Institute of Environmental Engineering, Wrocław University of Environmental and Life Sciences, 24 Grunwaldzki Sq., 50-363 Wrocław, Poland E-mail:
Water Sci Technol. 2020 May;81(9):1863-1869. doi: 10.2166/wst.2020.235.
Wastewater treatment in semi-natural systems, such as a hydroponic lagoon operating as the third stage of purification, is becoming more and more popular because of the efficiency of nutrient removal. Very often treatment processes in hydroponic ditches are supported by algal growth, which can cause an increase in the concentration of total suspended solids in the outflow from the wastewater treatment plant. The aim of this study was to analyse changes in the granulometric composition of particles in the hydroponic lagoon operating as the third stage of wastewater purification in a municipal wastewater treatment plant (WWTP) in Poland. Measurements of the particle sizes were made with the use of the laser diffraction method. The results showed that the size of the particles in the hydroponic lagoon varied from 0.01 to 1000 μm. Analyses of the average diameters D(3.2) and D(4.3) showed that particles have low reactivity but good sedimentation properties and their fractal dimensions are usually higher than 2.0, which indicated that they had well-developed surfaces. Most of the particles flowing out of the WWTP were probably algae or particles that could adsorb other pollutants onto their surfaces. The use of laser granulometry for particle identification might be useful in characterizing the total suspended solids as well as helping to develop cheaper and more efficient methods for its removal.
半自然系统中的废水处理，例如作为第三级净化的水培泻湖，由于其去除营养物的效率而变得越来越受欢迎。水培沟渠中的处理过程通常得到藻类生长的支持，这会导致污水处理厂流出物中总悬浮固体的浓度增加。本研究的目的是分析波兰市立污水处理厂（WWTP）中作为第三级废水净化的水培泻湖中颗粒的粒度组成变化。使用激光衍射法进行颗粒尺寸测量。结果表明，水培泻湖中颗粒的大小从 0.01 到 1000μm 不等。对平均直径 D(3.2)和 D(4.3)的分析表明，颗粒的反应性低，但沉降性能好，其分形维数通常高于 2.0，这表明它们具有发达的表面。从 WWTP 流出的大部分颗粒可能是藻类或能够在其表面吸附其他污染物的颗粒。激光粒度测定法用于颗粒识别可能有助于表征总悬浮固体，并有助于开发更廉价、更有效的去除方法。
