基于臭氧对建材挥发性有机物作用的人居环境新风量快速计算方法

Ventilation is commonly used as a basic means to supply outdoor air to indoor environment to dilute volatile organic compound (VOC) concentrations and achieve better indoor air quality. Occupants are traditionally considered as the main source for indoor pollutants. However, VOCs that emitted from building materials could the leading source for pollution in low-occupant-density indoor environment, e.g., offices and residential buildings. This proposal focuses on the two major variables that may affect the gas-phase VOC concentrations, i.e., ventilation rate and ozone-initiated reactions, and proposes to present a new pack of rapid methods to predict ventilation rate while considering ozone chemistry as follows: 1) to develop a method to prioritize the VOCs presented initially in the building materials; 2) to develop decoupled/coupled method to cover gas-phase reactions and surface reactions with ozone. Furthermore, sensitivity analysis will be performed for the steady-state model and threshold analysis will be conducted for the unsteady-state model; 3) to summarize a rapid method to estimate gas-phase VOC concentrations for both uniform and ununiformed environment based on the sensitivity and threshold analysis; 4) to propose a model to predict the apparent initial formaldehyde concentration in the material-phase while interacting with ozone, the model will be validated by experimental study; 5) to develop a rapid method to determine ventilation rate based on indoor exposures to gas-phase VOCs with the influence of ozone; 6) to propose a data structure for a building material emission database that could be used to predict ventilation rate for offices and residential buildings based on the ventilation rate determination method proposed in this research.

新风是稀释室内污染物最主要的手段。传统新风量计算思路认为人是室内主要污染源，而办公建筑等人居环境中主导污染物是建材、家具散发的挥发性有机物（VOC），传统方法存在健康风险。本项目旨在研究影响室内VOC浓度和人体暴露的两大敏感因素——新风量与臭氧引发的反应，拟完成：1、提出建材VOC散发优先控制目标筛选方法；2、建立臭氧与目标VOC单相、异相反应独立/耦合模型，进而对稳态、非稳态条件下主要关键参数分别进行敏感性和临界值分析；3、提出均匀/非均匀环境臭氧作用下建材散发VOC气相浓度的快速估计法；4、提出臭氧对典型建材甲醛初始（表观）可散发浓度的影响评价模型并进行实验验证；5、建立新风量指标快速计算方法，进行实验验证并提出适用于新风量预测的建材、家具VOC散发数据库数据构成。以此建立基于臭氧对建材散发VOC作用的人居环境新风量快速计算方法体系，为我国人居环境新风量指标确定提供理论技术支撑。

装饰装修材料、家具等散发的挥发性有机物（VOCs）是人居环境中主要的污染物，现代新风量理论在如何科学量化VOC引起的通风需求上一直在进行探索。与此同时，近年来大气环境中臭氧的背景浓度也常处于高污染态势。由于臭氧具有强氧化性，其进去室内后不仅会通过气相反应改变空气中部分由材料散发的VOC等污染物的浓度，也会通过气相及与材料表面的异相反应产生其他二次污染物，改成室内空气污染物的组分。由此进一步引发的通风需求变化规律是新风量理论中亟待解决的科学问题。本项目通过理论分析和实验研究，从以下五个方面展开探索：① 基于单一污染物指标和组合式指标，建立了室内建材VOC目标污染物的筛选方法，以加拿大国家研究院（NRC）建材散发数据库散发数据为基础，获得了建议优先控制散发量的VOC污染物清单；② 建立了臭氧与目标VOC气相、异相反应的耦合模型。理论分析了目标污染物、典型建材与臭氧在常见室内环境场景下反应后导致的气相浓度变化规律。评估了臭氧引发的反应对优先控制散发量的VOC污染物清单的组成、排序等的影响；③ 开展了低/高浓度臭氧（<10 ppbv、100 ppbv及300 ppbv）在板材、人造革等十种常见室内材料表面的沉积速度实验；④ 开展了低/高浓度臭氧对典型建材甲醛、苯系物、TVOC等一、二次污染物散发率的影响；⑤ 从工程指标角度，讨论并评估了由臭氧引发的反应对室内新风需求的影响程度、人员设计密度和人均设计空间的矛盾、低密人群建筑与高密人群建筑的划分，等新风量指标寻优过程中的关键因素。在上述研究工作基础上，本项目最终形成了：① 室内建材优先控制散发率的VOC清单数据库；② 常见室内材料——臭氧沉积速度数据库；③ 常见室内材料——臭氧引发反应的一、二次污染物数据库；④ 我国住宅、公共建筑等两类民用建筑室内空气污染物（含臭氧）的检测/监测文献汇编数据库，等四类室内空气品质基础数据库，上述成果可为后续我国人居环境新风量理论和指标的确定提供参考依据。