Sulfate reduction and mixotrophic sulfide-utilization denitrification integrated biofilm process for sulfate-laden wastewater treatment and sulfur recovery

2015 ◽  
Vol 71 (12) ◽  
pp. 1852-1858 ◽  
Author(s):  
Wei Li ◽  
Xiao Liang ◽  
Jianguo Lin ◽  
Binxia Cao ◽  
Ping Guo ◽  
...  

A novel and integrated biofilm process – the sulfate reduction (SR) and mixotrophic (MR) sulfide-utilization denitrification process (SMSD) – was recently proposed for sulfate treatment and sulfur recovery. The process consisted of two bioreactors: a 5.1 L anaerobic upflow reactor for SR, and a 3.5 L anaerobic upflow reactor for MR desulfurization–denitrification. The experiment was conducted for 370 days to evaluate the performance of SMSD at various sulfate concentrations and hydraulic retention times. The process successfully achieved sulfate, organics and nitrogen compound removal efficiencies of 94.1, 97.7 and 99.1%, respectively. Sulfate was predominantly converted to element sulfur, while nitrate and nitrite were finally converted to nitrogen gas. In SR, with the help of high pH and sponge cubes with various bacteria, 97.5% of sulfide conversion efficiency and 540 mgS/L of sulfide were obtained. In MR, sulfide was removed up to 100% and was partially oxidized to sulfur. The extent of heterotrophic denitrification, which ranged from 35.8 to 59.8%, depended on the categories of electron acceptors.

2006 ◽  
Vol 6 (2) ◽  
pp. 125-130
Author(s):  
C.-H. Hung ◽  
K.-H. Tsai ◽  
Y.-K. Su ◽  
C.-M. Liang ◽  
M.-H. Su ◽  
...  

Due to the extensive application of artificial nitrogen-based fertilizers on land, groundwater from the central part of Taiwan faces problems of increasing concentrations of nitrate, which were measured to be well above 30 mg/L all year round. For meeting the 10 mg/L nitrate standard, optimal operations for a heterotrophic denitrification pilot plant designed for drinking water treatment was investigated. Ethanol and phosphate were added for bacteria growing on anthracite to convert nitrate to nitrogen gas. Results showed that presence of high dissolved oxygen (around 4 mg/L) in the source water did not have a significantly negative effect on nitrogen removal. When operated under a C/N ratio of 1.88, which was recommended in the literature, nitrate removal efficiency was measured to be around 70%, sometimes up to 90%. However, the reactor often underwent severe clogging problems. When operated under C/N ratio of 1.0, denitrification efficiency decreased significantly to 30%. Finally, when operated under C/N ratio of 1.5, the nitrate content of the influent was almost completely reduced at the first one-third part of the bioreactor with an overall removal efficiency of 89–91%. Another advantage for operating with a C/N ratio of 1.5 is that only one-third of the biosolids was produced compared to a C/N value of 1.88.


2015 ◽  
Vol 47 (1) ◽  
pp. 128-136
Author(s):  
Lizhu Hou ◽  
Xue Xu ◽  
Yiran Song ◽  
Chuanping Feng

To enhance denitrification performance of soil infiltration, a soil infiltration system incorporated with heterotrophic denitrification (TSISHD) for urban runoff treatment was developed. Sawdust and grass powders were added in the anaerobic stage (ANS) to provide organic carbon sources for the denitrification process, and the reduction environment was improved by iron addition in the ANS. Aerobic respiration and nitrification primarily occurred in the upper aerobic stage (AES), which removed 86.68% of the chemical oxygen demand (COD) and 91.80% of the NH+4-N. Moreover, heterotrophic denitrification occurred in the bottom ANS when added sawdust and grass powders were used as a carbon source. Overall, the TSISHD showed remarkable removal efficiencies of 88.29%, 82.50%, 92.05%, and 78.10% for COD, NO−3-N, NH+4-N, and total phosphorus, respectively, and the corresponding effluent concentrations met the national quality standard of China for class V surface water. The removal efficiencies were significantly higher than those of the previous soil infiltration systems without inoculated microbes. The developed system has the potential to treat urban runoff.


2019 ◽  
Vol 80 (4) ◽  
pp. 634-643 ◽  
Author(s):  
Dandan Zhang ◽  
Li Cui ◽  
Rayan M. A. Madani ◽  
Hui Wang ◽  
Hao Zhu ◽  
...  

Abstract The effects of nitrite and nitrate on the integration of ammonium oxidization and sulfate reduction were investigated in a self-designed reactor with an effective volume of 5 L. An experimental study indicated that the ammonium oxidization and sulfate reduction efficiencies were increased in the presence of nitrite and nitrate. Studies showed that a decreasing proportion of N/S in the presence of NO2− at 30 mg·L−1 would lead to high removal efficiencies of NH4+-N and SO42–-S of up to 78.13% and 46.72%, respectively. On the other hand, NO3− was produced at approximately 26.89 mg·L−1. Proteobacteria, Chloroflexi, Bacteroidetes, Chlorobi, Acidobacteria, Planctomycetes and Nitrospirae were detected in the anaerobic cycle growth reactor. Proteobacteria was identified as the dominant functional bacteria removing nitrogen in the reactor. The nitritation reaction could promote the sulfate-reducing ammonium oxidation (SRAO) process. NH4+ was converted to NO2 and other intermediates, for which the electron acceptor was SO42−. These results showed that nitrogen was converted by the nitrification process, the denitrification process, and the traditional anammox process simultaneously with the SRAO process. The sulfur-based autotrophic denitration and denitrification in the reactor were caused by the influent nitrite and nitrate.


Water ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 389 ◽  
Author(s):  
Cheng Dong ◽  
Mengting Li ◽  
Lin-Lan Zhuang ◽  
Jian Zhang ◽  
Youhao Shen ◽  
...  

Subsurface flow constructed wetland (SSFCW) has been applied for wastewater treatment for several decades. In recent years, the combination of ferric-carbon micro-electrolysis (Fe/C-M/E) and SSFCW was proven to be an effective method of multifarious sewage treatment. However, Ferric substrate created a relatively reductive condition, decreased the oxidation efficiency of NH4+-N, and blocked the following denitrification process, which led to the low removal efficiencies of NH4+-N and total nitrogen (TN). In this study, partial aeration was introduced into the ferric-carbon micro-electrolysis SSFCW (Fe/C-M/E CW) system to solve the problem above. The water quality and nitrogen-related functional genes of bacteria on the surface of substrate were measured for mechanism exploration. The results showed that, the removal efficiencies of NH4+-N and total phosphorus (TP) in an aerated Fe/C-M/E CW system were 96.97% ± 6.06% and 84.62% ± 8.47%, much higher than 43.33% ± 11.27% and 60.16% ± 2.95% in the unaerated Fe/C-M/E CW systems. However, the TN removal in Fe/C-M/E CW system was not enhanced by aeration, which could be optimized by extending more anoxic section for denitrification.


1970 ◽  
Vol 7 (1) ◽  
pp. 121-126 ◽  
Author(s):  
Iswar Man Amatya ◽  
Bhagwan Ratna Kansakar ◽  
Vinod Tare ◽  
Liv Fiksdal

Nitrate removal in groundwater was carried out by biological method of denitrification process. The denitrification and without denitrification were performed in two different sets of reactors. Each reactor consists of two columns connected in series packed with over burnt bricks as media. The filtration rate varied from 5.3 to 52.6 m/day for denitrification process. The ammonia, nitrate and nitrite nitrogen concentrations were measured at inlet, intermediate ports and outlet. The temperature varied from 10 to 30°C at 2°C intervals. The results demonstrated that high amount of nitrate nitrogen removed in groundwater at denitrification process. The nitrate nitrogen removed by denitrification varied from 3.50 to 39.08 gm/m3/h at influent concentration from 6.32 to 111.04 gm/m3/h. Denitrification was found more significant above 16°C.Key words: Over burnt brick, Denitrification, Filtration rate and TemperatureJournal of the Institute of Engineering, Vol. 7, No. 1, July, 2009 pp. 121-126doi: 10.3126/jie.v7i1.2070 


2008 ◽  
Vol 58 (7) ◽  
pp. 1405-1413 ◽  
Author(s):  
Takahiro Yamashita ◽  
Ryoko Yamamoto-Ikemoto

Phosphorus removal and denitrification using iron and wood as electron donors were examined in a laboratory-scale biological filter reactor. Phosphorus removal and denitrification using iron and wood continued for 1,200 days of operation. Wood degradation by heterotrophic denitrification and iron oxidation by hydrogenotrophic denitrification occurred simultaneously. In the biofilm inside the wood, not only heterotrophic denitrification activity but also sulfate reduction and sulfur denitrification activities were recognized inside the wood, indicating that a sulfur oxidation-reduction cycle was established. Sulfate reduction and denitrification were accelerated with the addition of cellulose. Microbial communities of sulfate-reducing bacteria by PCR primer sets could be amplified in the biofilm in the reactors. The dissimilatory sulfite reductase gene and the 16S rRNA gene of six phylogenetic groups of SRB in the reactors were analyzed. Some SRB group-specific primers-amplification products were obtained inside the wood and around iron.


2004 ◽  
Vol 50 (11) ◽  
pp. 135-141 ◽  
Author(s):  
S.H. McMurray ◽  
R.L. Meyer ◽  
R.J. Zeng ◽  
Z. Yuan ◽  
J. Keller

The denitrification process, namely the reduction of nitrate (NO3−) to nitrogen gas (N2), often cannot be simply modelled as a single step process. For a more complete and comprehensive model the intermediates, particularly nitrite (NO2−) and nitrous oxide (N2O), need to be investigated. This paper demonstrates the integration of titrimetric measurements and off-gas analysis with on-line nitrite plus nitrate (NOx−) biosensors, highlighting the necessity of measuring process intermediates with high time-scale resolution to study and understand the kinetics of denitrification. Investigation of activated sludge from a full-scale treatment plant showed a significant accumulation of NO2−, which appeared to impact on the overall denitrification rate measured as NOx− reduction or N2 production. A different sludge obtained from a lab-scale bioreactor produced N2O instead of N2 as the end product of denitrification. The two examples both illustrate the complexity of denitrification and stress the need for the more versatile and detailed measurement procedures, as presented in this paper.


2014 ◽  
Vol 12 (2) ◽  
pp. 683-693
Author(s):  
Nouceiba Adouani ◽  
Lionel Limousy ◽  
Thomas Lendormi ◽  
Eberhard O. Voit ◽  
Olivier Sire

Abstract Matching experimental and theoretical approaches have often been fruitful in the investigation of complex biological processes. Here we develop a novel non-conventional model for the denitrification of waste water. Earlier models of the denitrification process were compiled by the International Association on Water Quality group. The Activated Sludge Models 1–3, which are the most frequently used all over the world, are presently not adapted towards the integration of both nitrous and nitric oxide emissions during the denitrification process. In the present work, a Generalized Mass Action model, based on Biochemical Systems Theory, was designed to simulate the nitrate reduction observed in specific experimental conditions. The model was implemented and analysed with the software package PLAS. Data from a representative experiment were chosen (T=10°C, pH=7, C/N=3, with acetate as carbon source) to simulate greenhouse NO and N2O gas emissions, in order to test hypotheses about the corresponding bacterial metabolic pathways. The results show that the reduction of nitrate and nitrite is kinetically limiting and that nitrate reduction is limited by diffusion and support that distinct microbial subpopulations are involved in the denitrification pathway, which has consequences for NO emissions.


Science ◽  
2016 ◽  
Vol 351 (6274) ◽  
pp. 703-707 ◽  
Author(s):  
S. Scheller ◽  
H. Yu ◽  
G. L. Chadwick ◽  
S. E. McGlynn ◽  
V. J. Orphan

2013 ◽  
Vol 316-317 ◽  
pp. 854-859
Author(s):  
Yu Chuan Cai ◽  
Yong Jian Liu ◽  
Xiang Fang Li ◽  
Yan Zun Li ◽  
Xiao Lin Zhang ◽  
...  

Nowadays most heavy oil reservoirs are developed by thermal recovery methods, such as steam huff - puff and steam flooding. At the late stage of heavy oil steam drive, because of steam overlap in the upper reservoir formation, steam channeling can easily occur in production well. The research has shown that development effect of steam - nitrogen compound drive is not as good as consideration after steam channeling. But by injecting water slug can decrease the effect of steam channeling. For increasing water phase saturation in high permeability channel, steam and nitrogen gas relative permeability will decrease. As result, it will enlarge the reservoir vertical producing degree, and at the same time take full advantage of the oil displacement effect of steam - nitrogen compound drive. Through the numerical simulation, the study found that, steam - water - nitrogen compound drive technology can achieve better recovery degree using high hot water temperature and shorter injection time.


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