School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, China; Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, China.
School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, China; Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, China.
Environ Pollut. 2019 Dec;255(Pt 2):112989. doi: 10.1016/j.envpol.2019.112989. Epub 2019 Aug 1.
Large-area hypoxia of urban landscape water often causes the emissions of harmful gases in summer, which not only reduces its sensory effects, but also brings a potential threat to aquatic ecosystem and human health. This study explored the dose effects of calcium peroxide (CaO) on inhibiting harmful gases emissions and restoring the scenic effect (including visual sense and olfactory sense) of anoxic/anaerobic landscape water system. The results indicated that the emissions of HS, CO and CH from the anoxic/anaerobic water system were obviously inhibited in the reactors with CaO additions and the effect was positively correlated with the CaO dose. Meanwhile, the concentrations of total chemical oxygen demand (TCOD) and soluble sulfide (S), and turbidity in the overlying water (the water-layer above the sediment-water interface) were also decreased in the reactors dosed with CaO. The reason was ascribed to the improvement of the anoxic/anaerobic condition in the water system and the increase of the species richness, bacteria count and aerobic microorganism abundance in sediment. Furthermore, 0.12 kg-CaO m-sediment was selected as the optimal dose, which was based on considering the inhibiting effect of the harmful gases emissions, comprehensive influence and costs. Compared with control check (CK, the reactor without adding CaO), the optimal dose of CaO could reduce 75.10% CH, 81.02% CO and 100% HS in gases, and decrease 81.52% S, 42.85% TCOD and 84.01% turbidity in the overlying water. In conclusion, all the dosages of CaO could improve the anoxic condition of water system and 0.12 kg-CaO m-sediment was the optimal dose in inhibiting harmful gases emissions, which could keep an excellent water quality in this simulation experiment. Therefore, this study may provide a feasible method and the optimal dose for inhibiting the emissions of harmful gases and restoring the scenic effect in the similar anoxic/anaerobic landscape water.
大面积的城市景观水缺氧通常会导致夏季有害气体的排放，这不仅降低了其感官效果，还对水生态系统和人类健康带来潜在威胁。本研究探索了过氧钙（CaO）对抑制缺氧/厌氧景观水系统有害气体排放和恢复景观效果（包括视觉和嗅觉）的剂量效应。结果表明，添加 CaO 的反应器中，缺氧/厌氧水系统中的 HS、CO 和 CH 排放明显受到抑制，且效果与 CaO 剂量呈正相关。同时，添加 CaO 的反应器中，水层（底泥-水界面以上的水层）中总化学需氧量（TCOD）和可溶性硫化物（S）以及浊度的浓度也降低了。这归因于水系统缺氧/厌氧条件的改善以及底泥中物种丰富度、细菌计数和需氧微生物丰度的增加。此外，基于有害气体排放抑制效果、综合影响和成本考虑，选择 0.12 kg-CaO m-底泥为最佳剂量。与对照（未添加 CaO 的反应器）相比，CaO 的最佳剂量可减少气体中 75.10%的 CH、81.02%的 CO 和 100%的 HS，以及水层中 81.52%的 S、42.85%的 TCOD 和 84.01%的浊度。总之，所有 CaO 剂量均可改善水系统的缺氧条件，0.12 kg-CaO m-底泥是抑制有害气体排放的最佳剂量，可在模拟实验中保持优异的水质。因此，本研究可为类似缺氧/厌氧景观水系统中有害气体排放的抑制和景观效果的恢复提供可行的方法和最佳剂量。
