基于协同反硝化脱氮的光伏废水处理

以光伏废水为研究对象，利用启动成功的协同反硝化反应器，在进水F-浓度为800mg/L，NO₃^--N为350mg/L的条件下，控制进水C/N为0.7左右，实现反硝化过程无需酸碱调控，TN去除率为90%以上，TN去除速率为2.0~2.5kg/（m³·d）.除氟试验表明，通过投加CaO初步除氟能将F-浓度降低至800mg/L，同时将pH提升至7.68，满足协同反硝化的pH范围（7.5~8.5）要求；二次除氟能有效降低废水中残余的F-及协同反硝化生成的SO₄^2-.针对多数含F-浓度超过800mg/L的光伏废水，可采用先初步除氟、协同反硝化脱氮，最终二次除氟、除硫酸盐的工艺路线.相比于完全异养反硝化脱氮处理光伏废水，采用协同反硝化可节约脱氮成本0.82元/t.

Photovoltaic wastewater treatment based on a combined heterotrophic and sulfur-based autotrophic denitrification technology

Photovoltaic wastewater was used as the influent of a combined heterotrophic and sulfur-based autotrophic denitrification reactor. When the influent F^- concentration was 800mg/L, NO₃^--N concentration was 350mg/L, TOC/N was 0.7, the nitrogen removal rate and denitrification efficiency of the reactor reached 2.0~2.5kg/(m³·d) and 90% above without pH adjustment. Defluorination experiments indicated that F^- concentration of photovoltaic wastewater was decreased to 800mg/L by adding calcium oxide. Meanwhile, the pH of the wastewater was raised to 7.68, which met the pH(7.5~8.5) requirement of the combined denitrification. The remaining F^- and generated SO₄^2- in combined denitrification were removed effectively by secondary defluorination. Photovoltaic wastewater containing high F^- concentration (800mg/L above) could be treated by preliminary defluorination, combined denitrification and secondary defluorination. In terms of the cost of denitrification in photovoltaic wastewater treatment, the combined denitrification could save 0.82yuan/t compared with unit cost of the heterotrophic denitrification.