Effect of dissolved oxygen on heterotrophic denitrification using poly(butylene succinate) as the carbon source and biofilm carrier

2014 ◽  
Vol 171 ◽  
pp. 152-158 ◽  
Author(s):  
Guozhi Luo ◽  
Li Li ◽  
Qian Liu ◽  
Guimei Xu ◽  
Hongxin Tan
2014 ◽  
Vol 665 ◽  
pp. 469-478
Author(s):  
Guo Zhi Luo ◽  
Wen Jing Sun ◽  
Qian Liu ◽  
Yu Hu ◽  
Hong Xin Tan

Biodegradable polymer pellets (BDPs) can act as biofilm carrier and as water insoluble carbon source for denitrification simultaneously, which is accessible only by enzymatic attack. It is expected that organic carbon source for heterotrophic denitrification by using BDPs will not be overdose or shortage. The current batch experiment was conducted to examine if the PBS would supply enough carbon source to the denitrification with high concentration nitrate. The initial nitrate nitrogen (NO3--N) concentrations were 100 mg NO3-N/l (T1), 300 mg NO3-N/l (T2) and 500 mg NO3-N/l (T3) respectively. The results showed that the initial nitrate concentrations have significant effects on the removal of nitrate nitrogen and total nitrogen (TN) using PBS as carbon source. The efficiencies of removal of nitrate and TN in T1 were almost 100%. The amounts of NO3--N and TN that were removed in T2 were 286.60±6.66 mg NO3-N/g PBS (in dry wt), which was significantly higher than that of T1 and T3. Accumulation of ammonium and nitrite were observed in T2 and T3. The morphological changes and the weight losses observed for PBS granules indicated that good degradation occurred in static denitrification environments. But the insufficient of carbon sources for denitrification in T2 and T3 was observed.


2016 ◽  
Vol 216 ◽  
pp. 1004-1013 ◽  
Author(s):  
Yun-Jie Ruan ◽  
Ya-Le Deng ◽  
Xi-Shan Guo ◽  
Michael B. Timmons ◽  
Hui-Feng Lu ◽  
...  

2015 ◽  
Vol 71 (7) ◽  
pp. 1019-1025 ◽  
Author(s):  
Chuanfu Wu ◽  
Danqi Tang ◽  
Qunhui Wang ◽  
Juan Wang ◽  
Jianguo Liu ◽  
...  

A suitable carbon source is significant for biological nitrate removal from groundwater. In this study, slow-release carbon sources containing polylactic acid (PLA) and starch at 8:2, 7:3, 6:4, 5:5, 4:6, and 3:7 ratios were prepared using a blending and fusing technique. The PLA/starch blend was then used as a solid carbon source for biological nitrate removal. The carbon release rate of PLA/starch was found to increase with increased starch content in leaching experiments. PLA/starch at 5:5 mass ratio was found to have the highest denitrification performance and organic carbon consumption efficiency in semi-continuous denitrification experiments, and was also revealed to support complete denitrification at 50 mg-N/L influent nitrate concentration in continuous experiments. The effluent nitrate concentration was <2 mg NO3–-N/L, which met the national standard (GB 14848-93) for groundwater. Scanning electron microscopy results further showed that the surface roughness of PLA/starch increased with prolonged experimental time, which may be conducive to microorganism attachment. Therefore, PLA/starch was a suitable carbon source and biofilm carrier for groundwater remediation.


Author(s):  
Qian Zhang ◽  
Xue Chen ◽  
Heng Wu ◽  
Wandong Luo ◽  
Xiangyang Liu ◽  
...  

In recent years, there is a trend of low C/N ratio in municipal domestic wastewater, which results in serious problems for nitrogen removal from wastewater. The addition of an external soluble carbon source has been the usual procedure to achieve denitrification. However, the disadvantage of this treatment process is the need of a closed, rather sophisticated and costly process control as well as the risk of overdosing. Solid-phase denitrification using biodegradable polymers as biofilm carrier and carbon source was considered as an attractive alternative for biological denitrification. The start-up time of the novel process using PCL (polycaprolactone) as biofilm carrier and carbon source was comparable with that of conventional process using ceramsite as biofilm carrier and acetate as carbon source. Further, the solid-phase denitrification process showed higher nitrogen removal efficiency under shorter hydraulic retention time (HRT) and low carbon to nitrogen (C/N) ratio since the biofilm was firmly attached to the clear pores on the surface of PCL carriers and in this process bacteria that could degrade PCL carriers to obtain electron donor for denitrification was found. In addition, solid-phase denitrification process had a stronger resistance of shock loading than that in conventional process. This study revealed, for the first time, that the physical properties of the biodegradable polymer played a vital role in denitrification, and the different microbial compositions of the two processes was the main reason for the different denitrification performances under low C/N ratio.


2013 ◽  
Vol 316-317 ◽  
pp. 625-628
Author(s):  
Jian Mei Zhang ◽  
Chuan Ping Feng ◽  
Si Qi Hong ◽  
Hui Ling Hao

The method of the heterotrophic denitrification remediation of nitrate-polluted groundwater involves the study of organic carbon sources as electron donor. The aim of the present study was to evaluate wheat straw for its ability to enhance denitrification in column experiments. The inlet concentration was 50.0 mgNO3--N/L and the column operated at the flow rate of 2.0 ml/min. The result showed that in the presence of wheat straw, highly reducing conditions were generated and complete removal of nitrate (>95%) was achieved, with less accumulation of nitrite. Consequently, wheat straw is an attractive carbon source for groundwater denitrification.


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