两种水质标准的再生水及补给后景观水对典型绿藻生长及生物质的影响

Effect of reclaimed water from two different water quality standards and their replenished landscape water on the growth and biomass of typical green algae

再生水回用于景观水体可以解决我国景观水体补水不足的问题,但也容易诱发水体富营养化.典型绿藻中的小球藻是水体富营养化的优势藻种,因此,了解影响小球藻新陈代谢的水质因素对控制富营养化非常重要.本研究以西安两处不同水质标准的再生水及其景观补水水体的水样对小球藻进行培养测定,采用冗余分析和显著性分析探究小球藻生长及生物质组分对水质指标响应程度.结果表明,再生水中氮、磷含量比景观水体高1.09%~12.5%,小球藻在杂用水水质标准和景观环境水质标准的再生水以及相应的补给后景观水中的比增长速率分别为0.469、0.438、0.362和0.289,而总生物质(脂质、多糖和蛋白质)的占比分别为49.98%、58.59%、76.59%和71.88%.通过冗余性分析发现TN和COD对小球藻的生长影响显著,总贡献率为57%;TN、COD和磷酸盐对微藻生化组成有显著影响,总贡献率为57.4%,显著性分析发现TN对藻类多糖的合成影响最显著,相关系数为0.669.基于此,可以采取化学混凝、生物种间竞争等方法降低再生水中营养物含量来有效控制水体富营养化.

The use of reclaimed water in landscape water can solve the problem of the insufficient water replenishment,but it is also easy to induce eutrophication.Chlorella vulgaris(C.vulgaris),a typical green alga is the dominant algal species in eutrophication water,thus,it is important to understand the water quality factors affecting the metabolism of C.vulgaris to control eutrophication.In this study,C.vulgaris was cultured with reclaimed water from two different water quality standards and their replenished landscape water in Xi'an,and the relevant indicators were also measured.Redundancy analysis and significance analyses were used to investigate the response degree of C.vulgaris growth and its biomass composition to water quality indicators.The results showed that the content of total nitrogen(TN)and total phosphorus in the reclaimed water was 1.09%~12.5%higher than that in landscape water.The specific growth rates of C.vulgaris in reclaimed water of water quality standard for urban miscellaneous use and for scenic environment use,and their corresponding replenished landscape water were 0.469,0.438,0.362 and 0.289,respectively,while the proportion of total biomass(lipids,polysaccharides and proteins)was 49.98%,58.59%,76.59%and 71.88%,respectively.The redundancy analysis showed that TN and COD had significant effects on the growth of C.vulgaris,with a total contribution of 57%,TN,COD and phosphate had significant effects on the biochemical composition of microalgae,with a total contribution of 57.4%.The significance analysis revealed that TN had the most significant effect on the synthesis of algal polysaccharides,and the correlation coefficient was 0.669.Based on this,chemical coagulation and biological interspecies competition can be adopted to reduce the nutrient loading in reclaimed water to effectively control the eutrophication.