曝二氧化碳气体对近具刺链带藻在高氨氮废水中生长的影响

养猪废水中丰富的氨氮可为微藻生长提供充足的养分,但是高质量浓度的氨氮会抑制微藻生长。以近具刺链带藻为对象,考查微藻在不同质量浓度的氨氮废水中的生长情况,同时探讨曝二氧化碳气体对微藻在高氨氮废水中生长的影响。结果表明,当初始氨氮的质量浓度为350~900 mg·L^-1时,近具刺链带藻的生长受到明显抑制,培养7 d后,各处理微藻的生物量仅增加0.08~0.13 g·L^-1。对不同质量浓度的氨氮废水进行曝二氧化碳气体处理后,微藻的生长情况明显改善,各处理的生物量增加了0.32~0.47 g·L^-1。未曝气处理的废水pH值呈下降趋势,7 d后下降了约0.50;而曝气条件下废水的pH值呈先增加后下降趋势,第1天到第2天上升了约1.50,从第2天开始至第7天,下降了约0.40。试验条件下氨氮的去除率在3.76%~20.10%。研究结果证实,过高质量浓度的氨氮确实会抑制微藻的生长,但通过曝二氧化碳气体的形式可以改善微藻在高质量浓度氨氮废水中的生长情况。

Effect of aeration with carbon dioxide on growth of Desmodesmus sp. CHX1 in wastewater with high concentration of ammonium nitrogen

The piggery wastewater can provide sufficient nutrient for the growth of microalgae. However, high concentration of ammonium nitrogen in the piggery wastewater may inhibit the growth of microalgae. In order to solve this problem, the inhibition of ammonia on Desmodesmus sp. CHX1 growth was investigated in the wastewater with initial ammonium concentration of 350-900 mg·L^-1, as well as the elimination effects of aeration with carbon dioxide. Results showed that the growth of Desmodesmus sp. CHX1 was inhibited by ammonia, with the increment of biomass of only 0.08-0.13 g·L^-1 after 7 days of culturing. Aeration with carbon dioxide could alleviate the inhibition of ammonia, with biomass increment of 0.32-0.47 g·L^-1. Decreasing trends of pH were observed in the wastewater without aeration, with the reduction of 0.5. While the pH in the aeration condition increased by 1.50 first and then decreased by 0.40. The ammonium was removed by 3.76%-20.10% in the experiment conditions. These results demonstrated that high concentration of ammonium nitrogen inhibited the growth of Desmodesmus sp. CHX1. Aeration with carbon dioxide could improve the growth of Desmodesmus sp. CHX1 in the wastewater with high concentration of ammonium nitrogen.