In-situ biological denitrification using pretreated maize stalks as carbon source for nitrate-contaminated groundwater remediation

2016 ◽  
Vol 17 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Tongyan Li ◽  
Wenqi Li ◽  
Chuanping Feng ◽  
Weiwu Hu
Keyword(s):  
Carbon Source ◽  
Removal Efficiency ◽  
Groundwater Remediation ◽  
Nitrate Removal ◽  
Contaminated Groundwater ◽  
Contaminated Water ◽  
Groundwater Treatment ◽  
Alternative Carbon Source ◽  
Maize Stalks

A simulation apparatus of in-situ groundwater remediation (SAIR) that used maize stalks pretreated with sodium hydroxide (MSSH) as a carbon source was designed for nitrate-contaminated groundwater treatment. Two experiments, RA and RB, were constructed in this SAIR. The removal performance of SAIR fed with real nitrate contaminated water was investigated under static and dynamic conditions. In the static remediation experiment, good removal efficiency (>95% for nitrate, 89% for total nitrogen) was observed in both experiments. However, nitrate removal efficiency did not differ greatly between RA and RB at a hydraulic retention time (HRT) of 15 d. Overall, these results indicate that MSSH has potential for use as an alternative carbon source for denitrification.

scholarly journals Feasibility of Remediation Lead, Nickel, Zinc, Copper and Cadmium Contaminated Groundwater by Calcium Sulfide

2021 ◽  
Author(s):  
Chin-Yuan Huang ◽  
Pei-Cheng Cheng ◽  
Jih-Hsing Chang ◽  
Yu-Chih Wan ◽  
Xiang-Min Hong ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Removal Efficiency ◽  
Groundwater Remediation ◽  
Contaminated Groundwater ◽  
Lead Removal ◽  
In Situ Stabilization ◽  
Nickel Zinc ◽  
Heavy Metals Contamination ◽  
Lead Nickel

Heavy metals contamination in groundwater often occurs in various industrial processes. Stud-ies have confirmed that polysulfide could reduce hexavalent chromium to trivalent chromium, achieving the effect of in-situ stabilization. For other heavy metals contamination in groundwa-ter, whether polysulfide also had a stabilizing ability to achieve in-situ remediation. This re-search focused on heavy metals except for chromium that often contaminated in groundwater, including lead, nickel, zinc, copper, and cadmium to explore the feasibility of using calcium polysulfide (CaSx) as an in-situ stabilization technology for these heavy metals contamination groundwater. Results showed that CaSx had a great removal efficiency for heavy metals lead, nickel, zinc, copper, and cadmium. However, for nickel, zinc, copper and cadmium, when CaSx was added excessively, complexes would be formed, causing the result of re-dissolve and this would also reduce the removal efficiency. Since it is difficult to accurately control the dosage of agents for in-situ groundwater remediation, the concentration of re-dissolved nickel, zinc, cop-per, and cadmium may not be able to meet the groundwater control standards. CaSx had high lead removal efficiency, and it would not cause re-dissolution due to excessive CaSx dosing. CaSx can be used as an in-situ stabilization technique for lead contaminated groundwater.

Comparison of denitrification performances using PLA/starch with different mass ratios as carbon source

2015 ◽  
Vol 71 (7) ◽  
pp. 1019-1025 ◽  
Author(s):  
Chuanfu Wu ◽  
Danqi Tang ◽  
Qunhui Wang ◽  
Juan Wang ◽  
Jianguo Liu ◽  
...  
Keyword(s):  
Carbon Source ◽  
Groundwater Remediation ◽  
Nitrate Concentration ◽  
Starch Content ◽  
Nitrate Removal ◽  
Carbon Sources ◽  
National Standard ◽  
Biofilm Carrier ◽  
Carbon Release ◽  
Biological Nitrate Removal

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.

scholarly journals Feasibility of Remediation Lead, Nickel, Zinc, Copper, and Cadmium-Contaminated Groundwater by Calcium Sulfide

Water ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2266
Author(s):  
Chin-Yuan Huang ◽  
Pei-Cheng Cheng ◽  
Jih-Hsing Chang ◽  
Yu-Chih Wan ◽  
Xiang-Min Hong ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Metal Contamination ◽  
Removal Rate ◽  
Contaminated Groundwater ◽  
Lead Removal ◽  
In Situ Stabilization ◽  
Nickel Zinc ◽  
Calcium Polysulfide ◽  
Lead Nickel

Metal contamination in groundwater often occurs in various industrial processes. Studies have confirmed that polysulfide could reduce hexavalent chromium to trivalent chromium, achieving the effect of in situ stabilization. For other metal contamination in groundwater, whether polysulfide also had a stabilizing ability to achieve in situ remediation. This research focused on metals in addition to chromium that often contaminated groundwater, including lead, nickel, zinc, copper, and cadmium, to explore the feasibility of using calcium polysulfide (CaSx) as an in situ stabilization technology for these metals’ contamination of groundwater. Results showed that CaSx had a great removal efficiency for metals lead, nickel, zinc, copper, and cadmium. However, for nickel, zinc, copper, and cadmium, when CaSx was added excessively, complexes would be formed, causing the result of re-dissolution, in turn reducing the removal efficiency. As it is difficult to accurately control the dosage of agents for in situ groundwater remediation, the concentration of re-dissolved nickel, zinc, copper, and cadmium may not be able to meet the groundwater control standards. CaSx had high lead removal efficiency and for a concentration of 100 mg/L, the dose of calcium polysulfide was more than the amount of 1/1200 (volume ratio of CaSx to groundwater). In addition, the removal rate was almost 100% and it would not cause re-dissolution due to excessive CaSx dosing. CaSx can be used as an in situ stabilization technique for lead-contaminated groundwater.

Nitrate removal efficiency of a mixotrophic denitrification wall for nitrate-polluted groundwater in situ remediation

2017 ◽  
Vol 106 ◽  
pp. 523-531 ◽  
Author(s):  
Rui Li ◽  
Chuanping Feng ◽  
Beidou Xi ◽  
Nan Chen ◽  
Yu Jiang ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Nitrate Removal ◽  
In Situ Remediation ◽  
Denitrification Wall

scholarly journals Nitrogen Removal Ability and Characteristics of the Laboratory-Scale Tidal Flow Constructed Wetlands for Treating Ammonium-Nitrogen Contaminated Groundwater

Water ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1326
Author(s):  
Amit Kumar Maharjan ◽  
Kazuhiro Mori ◽  
Tadashi Toyama
Keyword(s):  
Constructed Wetlands ◽  
Tidal Flow ◽  
Ammonium Nitrogen ◽  
Laboratory Scale ◽  
Contaminated Groundwater ◽  
Groundwater Treatment ◽  
N Removal ◽  
Ammonium N ◽  
Effective Technology

Constructed wetlands (CWs) are an effective technology to remove organic compounds and nitrogen (N) from wastewaters and contaminated environmental waters. However, the feasibility of CWs for ammonium-N (NH4+-N)-contaminated groundwater treatment is unclear. In this study, zeolite-based laboratory-scale CW was operated as a tidal flow CW with a cycle consisting of 21-h flooded and 3-h rest, and used to treat NH4+-N (30 mg L−1) contaminated groundwater. In addition to NH4+-N, nitrite (NO2−-N) and nitrate (NO3−-N) were also not detected in the effluents from the tidal flow CW. The N removal constant remained high for a longer period of time compared to the continuous flow CW. The higher and more sustainable N removal of the tidal flow CW was due to the in-situ biological regeneration of zeolite NH4+-N adsorption capacity. Vegetation of common reeds in tidal flow zeolite-based CW enhanced nitrification and heterotrophic denitrification activities, and increased the functional genes of nitrification (AOB-amoA and nxrA) and denitrification (narG, nirK, nirS, and nosZ) by 2‒3 orders of magnitude, compared to CW without vegetation. The results suggest that the combination of zeolite substrate, tidal flow, and vegetation is key for the highly efficient and sustainable N removal from NH4+-N contaminated groundwater.

scholarly journals In SituBiodiesel Production from Fast-Growing and High Oil ContentChlorella pyrenoidosain Rice Straw Hydrolysate

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Penglin Li ◽  
Xiaoling Miao ◽  
Rongxiu Li ◽  
Jianjiang Zhong
Keyword(s):  
Carbon Source ◽  
Rice Straw ◽  
Biomass Concentration ◽  
Chlorella Pyrenoidosa ◽  
Biodiesel Production ◽  
Microalgae Cultivation ◽  
Rice Straw Hydrolysate ◽  
Alternative Carbon Source ◽  
Methyl Ester Content

Rice straw hydrolysate was used as lignocellulose-based carbon source forChlorella pyrenoidosacultivation and the feasibility ofin situbiodiesel production was investigated. 13.7 g/L sugar was obtained by enzymatic hydrolyzation of rice straw.Chlorella pyrenoidosashowed a rapid growth in the rice straw hydrolysate medium, the maximum biomass concentration of 2.83 g/L was obtained in only 48 hours. The lipid content of the cells reached as high as 56.3%.In situtransesterification was performed for biodiesel production. The optimized condition was 1 g algal powder, 6 mLn-hexane, and 4 mL methanol with 0.5 M sulfuric acid at the temperature of 90°C in 2-hour reaction time, under which over 99% methyl ester content and about 95% biodiesel yield were obtained. The results suggested that the method has great potential in the production of biofuels with lignocellulose as an alternative carbon source for microalgae cultivation.

scholarly journals In situ Groundwater Treatment with Bioelectrochemical Systems (BES): Critical Review and Future Perspectives

2019 ◽  
Author(s):  
Daniele Cecconet ◽  
Fabrizio Sabba ◽  
Matyas Devecseri ◽  
Arianna Callegari ◽  
Andrea G. Capodaglio
Keyword(s):  
Groundwater Contamination ◽  
Groundwater Remediation ◽  
Scale Up ◽  
Bioelectrochemical Systems ◽  
Groundwater Treatment ◽  
The Past ◽  
Past Half Century ◽  
Past Half ◽  
Selection Of

Groundwater contamination is an ever-growing environmental issue, that has attracted much and undiminished attention for the past half century. Groundwater contamination originates from anthropogenic (e.g. hydrocarbons), natural compounds (e.g. nitrate and arsenic), or both; to tackle these contaminants different technologies have been tested during the years. Recently, bioelectrochemical systems (BESs) have emerged as a potential treatment for groundwater contamination, with in situ applications reported, that showed promising results. Nitrate and hydrocarbons (toluene, phenanthrene, benzene, BTEX and light PAHs) have been successfully removed, due to the interaction of microbial metabolism with poised electrodes, other than physical migration due to the electric field generated in BES. The selection of proper BESs relies on several factors and problems such as complexity of the groundwater, scale-up and energy requirements that need to be taken into account. Modelling efforts could help predict case scenarios and choose an ideal design and approach to solve these issues. In this review, we critically analyze in situ BES applications for groundwater remediation, focusing in particular on the different setups proposed, and we identify and discuss the existing research gaps in the field.

Behavior of solid carbon sources for biological denitrification in groundwater remediation

2012 ◽  
Vol 65 (9) ◽  
pp. 1696-1704 ◽  
Author(s):  
Jianmei Zhang ◽  
Chuanping Feng ◽  
Siqi Hong ◽  
Huiling Hao ◽  
Yingnan Yang
Keyword(s):  
Carbon Source ◽  
Wheat Straw ◽  
Groundwater Remediation ◽  
Nitrate Removal ◽  
Carbon Sources ◽  
Batch Experiments ◽  
Denitrification Activity ◽  
Leaching Experiments ◽  
Potential Carbon ◽  
Stimulation Of

The present study was conducted to compare the behavior of wheat straw, sawdust and biodegradable plastic (BP) as potential carbon sources for denitrification in groundwater remediation. The results showed that a greater amount of nitrogen compounds were released from wheat straw and sawdust than from BP in leaching experiments. In batch experiments, BP showed higher nitrate removal efficiency and longer service life than wheat straw and sawdust, which illustrated that BP is the most appropriate carbon source for stimulation of denitrification activity. In column experiments, BP was able to support complete denitrification at influent nitrate concentrations of 50, 60, 70, 80, and 90 mg NO3−-N/L, showing corresponding denitrification rates of 0.12, 0.14, 0.17, 0.19, and 0.22 mg NO3−-N.L−1.d−1.g−1, respectively. These findings indicate that BP is applicable for use as a carbon source for nitrate-polluted groundwater remediation.

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