过氧化钙片剂联合脱氮菌剂对黑臭水体的修复效果

Effect of Calcium Peroxide Tablets Combined with Nitrogen Removal Bacterial Agent on Remediation of Black and Odorous Water

以生物炭为填充材料,通过聚乙烯醇(PVA)包埋过氧化钙(CaO_(2))制备了一种具有缓释氧效果的CaO_(2)片剂(CPT),并应用于黑臭水体增氧。对比了3种CaO_(2)投加方式对泥水体系的影响,同时考察了CPT与异养硝化-好氧反硝化菌剂BT1联用对黑臭水体的修复效果。结果表明:相较于粉末覆盖和悬浊液底泥注射,CPT可显著延长供氧周期,并有效缓解了释氧过程对水体pH的冲击。在CPT的作用下,底泥生物降解能力较初始最高可提升3.88倍,40 d时上覆水TP去除率达到90.6%,底泥中钙结合态磷的占比提升至31%。CPT与BT1联用加速了上覆水中NH_(4)^(+)-N和TN的去除,底泥有机质和总可转化态氮的去除率分别提升至12.2%和17.6%,底泥AOA_amoA基因和AOB_amoA基因拷贝数最高分别达到了初始底泥的2.72和10.92倍。在CPT的影响下,底泥nirS基因拷贝数总体呈上升趋势,同时BT1的投加使底泥nirK基因拷贝数在第10天时显著增至4.54×10^(5) copies/g,促进了实验前期反硝化反应的进行。

Calcium peroxide tablets(CPT) with slow-release oxygen function was prepared by embedding calcium peroxide(CaO_(2)) in polyvinyl alcohol(PVA) with biochar as packing medium, and was applied to supply oxygen for black and odorous water. The effects of three CaO_(2) dosing strategies on sediment-water system were compared, and the remediation performance of CPT combined with heterotrophic nitrifying and aerobic denitrifying bacteria agent BT1 on black and odorous water was investigated. Compared with powder coating and suspension sediment injection, CPT could significantly prolong the oxygen supply time and effectively alleviate the impact of oxygen release process on the water pH. Under the action of CPT, the biodegradation capacity of the sediment was increased by up to 3.88 times compared with the initial level. On day 40, the TP removal rate in overlying water reached 90.6%,and the proportion of calcium-bound phosphorus in sediment was increased to 31%. CPT combined with BT1 accelerated the removal of NH_(4)^(+)-N and TN in overlying water, and the removal rates of organic matter and total transferable nitrogen in sediment were increased to 12.2% and 17.6%, respectively. The copy numbers of AOA_amoA and AOB_amoA genes in sediment reached 2.72 and 10.92 times of that in the initial sediment, respectively. The influence of CPT led to an overall increase trend of nirS gene copy number. In addition, the addition of BT1 significantly increased the nirK gene copy number in sediment to 4.54×10^(5) copies/g on day 10, which promoted the denitrification in the early stage of the experiment.