无外加碳源SBBR脱氮工艺及其控制方法研究

为提高脱氮效果并实现利用内碳源进行反硝化,开展了SBBR（以好氧-缺氧方式运行）处理生活污水的脱氮研究.在好氧阶段,SBBR中的生物膜能创造缺氧微环境并吸收、储存碳,实现了同步硝化反硝化,降低了硝态氮的浓度;在缺氧阶段,可利用内碳源实现剩余硝态氮的反硝化.溶解氧浓度的大小对好氧时间、好氧剩余硝态氮浓度和缺氧反应时间有较大影响,因而可以利用在线检测的DO作为曝气量控制参数.DO、pH和ORP值的变化具有规律性,反映了生物脱氮过程中耗氧和供氧、产酸和产碱、氧化和还原过程的变化.为准确判断好氧和缺氧反应过程的终点,并减少控制的滞后时间,建议以pH值的＂氨谷＂和ORP的＂硝酸盐膝＂作为主控制特征点分别指示硝化和反硝化的终点,而以ORP的＂氨肘＂和pH值的＂硝酸盐峰＂作为参考或辅助控制特征点.

Nitrogen Removal without External Carbon Source in SBBR and Its Control

Aiming to improve the removal of nitrogen and denitrify without adding external carbon source, an aerobic/anoxic SBBR was used to treat domestic wastewater for nitrogen removal. In the aerobic phase, carrier biofilm adsorbs and stores carbon for good nitrification and denitrification and less residual nitrate in the SBBR. In the anoxic phase, without adding external carbon source, internal carbon source is used for denitrification. DO in the SBBR affects aerobic time, residual nitrate and anoxic time. Online DO can be used as control parameter for aeration amount. The variations of DO, ORP and pH are relevant to biological process for nitrogen removal in the SBBR. These variations correspond to consumption and supply of oxygen, change of acid and alkali, and process of redox. In order to judge the end of nitrification and denitrification effectively, and decrease time for controlling lag, the ammonia valley of pH and the nitrate knee of ORP are used as main controlling parameters for nitrification and denitrification respectively. The ammonia elbows of ORP and the nitrate apex of pH are used as assistant control parameters.