基于内外回流污泥形态参数的水质预报

Water Quality Prediction Based on Morphological Parameters of Inner and Outer Returned Sludge

水质监测是污水厂至关重要的环节。为快速、准确地获取实时水质数据,以内、外回流污泥为研究对象,通过显微镜图像结合软件分析,分别得到内、外回流污泥各自絮体的形态参数,并结合污水处理厂运行参数,采用偏最小二乘(PLS)法对内、外回流污泥絮体形态参数与好氧池出水水质指标(CODe、BODe、TNe和TPe)进行了回归分析,建立内回流污泥回归模型(PLS1模型)和外回流污泥回归模型(PLS2模型),通过分析两个回归模型中活性污泥絮体形态参数与出水水质指标之间的相关性,比较了两个回归模型的拟合效果和预测效果。试验结果表明:PLS2模型的拟合效果和预测效果要优于PLS1模型,该模型对好氧池出水中CODe、BODe、TNe和TPe的预测系数Q2分别为0.736、0.665、0.753、0.716;出水污染物浓度与内回流污泥絮体密实度参数呈正相关关系,而其与外回流污泥絮体密实度参数呈负相关关系。本试验建立了污水处理厂宏观系统与活性污泥絮体微观性质之间的相关关系,为污水处理厂的水质监测提供了一种新的方法。

The monitoring of water quality is an important part of wastewater treatment plants.In this study, the research object is inner and outer returned sludge.The morphological parameters of flocs are obtained by microscope pictures combined with software analysis.We utilize the partial least squares method to make regression analysis on the effluent of the aerobic tank and morphological parameters of inner and outer returned sludge, establish the inner returned sludge model(PLS1 model) and the outer returned sludge model(PLS2 model), analyze the correlation between morphological parameters of activated sludge flocs and effluent water quality indexes in the two models, and compare the fitting and prediction effect of the two models.The experimental results indicate that the fitting and prediction effect of PLS2 model is better than that of PLS1 model.In PLS2 model, the prediction coefficients of CODe、BODe、TNeand TPeof aerobic effluent are 0.736,0.665,0.753 and 0.716,respectively.The aerobic effluent concentration is positively correlated with the density parameter of inner returned sludge flocs, but negatively correlated with that of outer returned sludge flocs.This experiment establishes the relationship between the macro system of wastewater treatment plants and the micro properties of activated sludge, and thus provides a new method for monitoring the effluent parameters of wastewater treatment plants.