Simultaneous removal of nitrate and sulfate from greenhouse wastewater by constructed wetlands.
Simultaneous removal of nitrate and sulfate from greenhouse wastewater by constructed wetlands.
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DOI：
10.2134/jeq2012.0306
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发表时间：
2013-07
影响因子：
2.4
通讯作者：
N. Gruyer;M. Dorais;B. Alsanius;G. Zagury
中科院分区：
文献类型：
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作者：
N. Gruyer;M. Dorais;B. Alsanius;G. Zagury
本研究评估了富碳潜流人工湿地在降低温室废水中高浓度硝酸盐（NO）和硫酸盐（SO）的有效性。人工湿地填充火山灰，种植香蒲（），并补充如下：（i）人工湿地与蔗糖（CW+S），湿地单位与2克/升的蔗糖溶液从第1周至第28周;（ii）人工湿地与堆肥（CW+C），湿地单位补充堆肥和锯末的反应混合物;（iii）从第1周至第18周，具有堆肥且不含蔗糖的人工湿地（CW+CNS），以及从第19周至第28周，具有堆肥和2g/L蔗糖的人工湿地（CW+CS）;以及（iv）人工湿地（CW）。在CW+S、CW+C和CW+CS三种组合中，适宜的C：N比（7：3.4）和氧化还原电位（-53 ~39 mV）对NO的去除率为95 ~ 99%.碳源不是富碳人工湿地反硝化的限制因素。在CW+S和CW+CS中，溶解有机碳（DOC）/SO比为0.36和0.28导致高硫酸盐还原菌（SRB）计数和高SO去除率（98%），而DOC/SO比为0.02（CW）至0.11（CW+C，CW+CNS）时观察到低活性。在第19周，当CW+CS中通过添加蔗糖增加有机C含量时，SRB计数从2.80增加到5.11 log[CFU+1] mL，导致与CW+S中测量的水平相似的水平（4.69 log[CFU+1] mL）。因此，高硫酸盐还原发生后反硝化，表明低DOC（38-54毫克/升）是限制因素。在CW，DOC浓度（9-10毫克/升）太低，维持有效的反硝化，因此，硫酸盐还原。此外，CW+S和CW+CS处理的沃茨中观察到的高浓度溶解硫化物通过添加FeCl而消除。
This study evaluated the effectiveness of C-enriched subsurface-flow constructed wetlands in reducing high concentrations of nitrate (NO) and sulfate (SO) in greenhouse wastewaters. Constructed wetlands were filled with pozzolana, planted with common cattail (), and supplemented as follows: (i) constructed wetland with sucrose (CW+S), wetland units with 2 g L of sucrose solution from week 1 to 28; (ii) constructed wetland with compost (CW+C), wetland units supplemented with a reactive mixture of compost and sawdust; (iii) constructed wetland with compost and no sucrose (CW+CNS) from week 1 to 18, and constructed wetland with compost and sucrose (CW+CS) at 2 g L from week 19 to 28; and (iv) constructed wetland (CW). During 28 wk, the wetlands received a typical reconstituted greenhouse wastewater containing 500 mg L SO and 300 mg L NO. In CW+S, CW+C, and CW+CS, appropriate C:N ratio (7:3.4) and redox potential (-53 to 39 mV) for denitrification resulted in 95 to 99% NO removal. Carbon source was not a limiting factor for denitrification in C-enriched constructed wetlands. In CW+S and CW+CS, the dissolved organic carbon (DOC)/SO ratios of 0.36 and 0.28 resulted in high sulfate-reducing bacteria (SRB) counts and high SO removal (98%), whereas low activities were observed at DOC/SO ratios of 0.02 (CW) to 0.11 (CW+C, CW+CNS). On week 19, when organic C content was increased by sucrose addition in CW+CS, SRB counts increased from 2.80 to 5.11 log[CFU+1] mL, resulting in a level similar to the one measured in CW+S (4.69 log[CFU+1] mL). Consequently, high sulfate reduction occurred after denitrification, suggesting that low DOC (38-54 mg L) was the limiting factor. In CW, DOC concentration (9-10 mg L) was too low to sustain efficient denitrification and, therefore, sulfate reduction. Furthermore, the high concentration of dissolved sulfides observed in CW+S and CW+CS treated waters were eliminated by adding FeCl.