黑臭水体沉积物中耗氧指标的垂向分布特征及其耗氧能力研究

Vertical distribution of oxygen-consuming indexes in black-odorous water body sediments and its oxygen-consuming ability

恢复溶解氧是黑臭水体治理的核心目标,内源沉积物的治理是黑臭水体整治的重要内容。但是黑臭水体沉积物耗氧能力的研究相对较少。以成都市两段黑臭水体为研究对象,分析了其沉积物中烧失量(LOI)、酸性挥发硫(AVS)、亚铁、氨氮等典型耗氧指标的垂向分布特征,研究了沉积物的耗氧能力。结果表明:黑臭水体沉积物中氨氮基本随深度的增加而升高;亚铁与深度的关系不明显;AVS大体表现出随深度增加先升高后降低的趋势;LOI大体呈现随深度增加先降低后升高的趋势。沉积物30min和24h的单位干泥耗氧量均与亚铁、LOI呈极显著正相关,是影响沉积物耗氧能力的最主要影响因子。因此,针对黑臭水体的治理,首先应该控制LOI和亚铁。

Recovery of dissolved oxygen is a main target for black-odorous water body remediation.Controlling of internal loadings in its sediments plays a vital role in the remediation.There were relatively few studies about sediments oxygen-consuming ability in black-odorous water bodies.In this study,two rivers in Chengdu were chosen as the research object.The vertical distribution characteristics of some typical oxygen-consuming indexes,such as lost of incineration(LOI),acid volatile sulphur(AVS),ferrous iron and ammonia nitrogen were analyzed.Further more,the sediment oxygen-sonsuming ability were studied.Results showed that:ammonia nitrogen increased with depth;ferrous iron had little relationship with depth;AVS increased first and decreased then with depth in general while LOI opposite.Oxygen-consuming demand per dry sludge of 30 min and 24 h had great significance with ferrous iron and LOI,respectively.In conclusion,LOI and ferrous iron were main factors that affected oxygen-consuming ability of sediments.Therefore,LOI and ferrous iron should be controlled first to treat black-odorous water body.