基于建材污染物逸出能力的散发速率预测模型及关键因素研究

Volatile organic compounds (VOCs) emitted durably from the building materials could pollute the indoor air quality (IAQ), and cause harmful effect to human’s health. Emission chamber tests are often conducted to characterize VOCs emission from building materials and consumer products to develop low-emission products. Meanwhile, several predicting models have been constructed. Generally, predictive models can be categorized into two groups. The first group consists of empirical models, which lack a physical basis and time-consuming. On the contrary, the second group of models is based on valid mass-transfer mechanisms with model parameters that have a clear physical meaning. However, the model parameters should be obtained by fitting other models to emission chamber test data, and the process of solving the control equations is very complex. Therefore, it is meaningful to build a model that not only could simply reflect and illustrate the emitting ability of VOCs from building materials, but also could accurately predict VOCs emission rate. Lots of studies indicated that the material characters and environmental conditions could affect VOCs emissions from building materials. Therefore, we classify impact factors as promoting elements and impeding elements innovatively. By combining the mass-transfer emission models and the mass balance equation in environmental chamber, a predicting model could be established based on promoting factor (a) and impeding factor (b). Furthermore, the relationships between parameters of materials、contaminants、 environmental conditions and a、b are also studied based on emitting tests of building materials and regression analysis. By principle component analysis, a quantitative model could be established between A、B and the key parameters, which could predict the emission rate of building materials accurately and evaluate the emitting ability of different materials. This research achievements could provide theoretical and technological guidance for the production technique of building materials and the source control of indoor pollution, which could promote the progress of improving indoor air quality.

室内建材持续散发VOCs造成的室内环境污染严重影响人们的生活和身心健康。针对传统的VOCs散发经验模型缺少物理基础，而传质模型因过于复杂方程难解的问题，为了简单直观反映材料污染物的逸出能力，本项目在实验数据基础上，创新性地将影响污染物散发的因素归结为逸出因素和阻隔因素，结合污染物对流传质过程与质量平衡理论，建立基于逸出因子a和阻隔因子b的污染物散发规律模型。同时根据环境舱实验和回归分析方法，研究逸出因子a、阻隔因子b与材料特性、污染物特性及环境条件等参数的关系，通过主成分分析建立a和b与关键因素间的定量关系模型，可实现对室内建材污染物散发快速准确预测和逸出能力的评价，为指导室内建材生产工艺和实现室内污染源头控制提供重要依据，对推动室内空气质量提升具有重要意义。

室内建材释放的挥发性有机化合物是室内空气污染的主要来源。目前国内外对室内建材VOCs散发预测研究模型主要包括经验模型和传质模型等，但相关模型或者太过复杂、参数难以求解，或者缺乏明确的物理意义，限制了预测模型的应用。本项目基于环境舱法对典型室内建材甲醛和VOCs等污染物散发进行研究，建立了基于逸出因子和阻隔因子的污染物散发速率预测模型，并将模型化为最简形式，建立了基于污染物短期散发预测长期散发的简单高精度预测方法，预测精度达80%以上。引入X射线三维断层扫描技术（XRT）分析材料三维结构，将其与SEM和MIP耦合，从多尺度综合表征了室内建材内部三维结构特征，获得了孔隙结构参数，建立了建材内部污染物扩散通道网络模型。根据建立的基于逸出因子和阻隔因子的污染物散发速率预测模型和材料多尺度三维表征方法，研究了材料结构和环境因素对污染物散发的影响，并建立了逸出因子和阻隔因子与材料结构参数和相对湿度、换气率等环境参数之间的关系模型。