中文关键词
粗放型绿色屋顶稳定污泥生物炭双基质层矿化反硝化 英文关键词green roofsstabilized sludgebiochardual-substrate structuremineralizationdenitrification |
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中文摘要 |
基质材料是影响粗放型绿色屋顶降雨出水水质的重要因素.采用污水厂稳定污泥作为基质主要营养成分,配合改良材料生物炭、双层基质结构,构建5个绿色屋顶中试设施,通过1a的现场实验,考察设施出水水质控制效果.结果表明将3%稳定污泥添加进粗放型绿色屋顶基质中,出水总氮(TN)和硝氮(NO3--N)的年平均质量浓度为3.27mg·L-1和1.61mg·L-1,在上海当地降雨与气温条件下稳定污泥的使用不会导致TN和NO3--N大量淋失;为改善使用污水厂稳定污泥作为营养基质的设施的出水水质,添加生物炭作为基质改良成分,出水中TN和NO3--N年平均质量浓度下降至2.16mg·L-1和1.38mg·L-1,吸附层的设置可降低出水总磷(TP)和化学需氧量(COD)浓度;对各中试设施系统进行TN平衡分析表明,经过一个汛期的使用,基质中存留的TN占到初始量的55%以上,污泥作为营养基质可以满足植物较长时间的生长需求.添加生物炭后基质存留TN减少和出水NO3--N浓度降低,分别与落干期期间矿化作用、降雨期间反硝化作用增强有关.从污染物质量负荷的角度出发,污泥不是营养物质N的污染源,是P的污染源.添加生物炭并设置双层结构能有效降低设施TN和COD出水负荷. |
英文摘要 |
Substrate type is an important factor affecting the quality of water deriving from rainfall onto extensively green roofed areas. Here, stabilized sludge was used as the main nutrient component of the substrate combined with biochar and a dual-substrate structure. Five green roof pilot facilities were constructed, and the effect of control measures on effluent quality was analyzed. The results showed that the stabilized sludge dosage was 3%, and the annual average mass concentrations of total nitrogen (TN) and nitrate nitrogen (NO3--N) were 3.27 mg·L-1 and 1.61 mg·L-1. The use of stabilized sludge as a nutrient component under real rainfall and temperature conditions in Shanghai did not cause significant leaching of TN and NO3--N. In order to further improve the quality of the effluent, biochar was used as an amendment measure. As a result, the concentrations of TN and NO3--N in the effluent were decreased to 2.16 mg·L-1 and 1.38 mg·L-1, respectively. Using an adsorption layer of pumice can alleviate the leaching of total phosphorus (TP) and chemical oxygen demand (COD). For the total nitrogen budget of each pilot facility, the retained TN was about 55% of the original TN after one year of operation. Thus, stabilized sludge could be used as a nutrient substrate to meet the long-term requirements of plants. In the substrate with biochar, the retained TN in the substrate and the NO3--N concentration in the effluent was decreased, which was related to the mineralization of organics during dry periods and the enhancement of denitrification during rainfall periods. Stabilized sludge was not a polluting source of N but was a source of P. Using biochar and a dual-substrate structure can effectively reduce the TN and COD load of the tested green roof facilities. |
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https://www.hjkx.ac.cn/hjkx/ch/reader/create_pdf.aspx?file_no=20190825&flag=1&journal_id=hjkx&year_id=2019