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 The effect of aerated rock filter geometry on the rate of nitrogen removal from facultative pond effluents

2011 ◽  
Vol 63 (5) ◽  
pp. 841-844 ◽  
Author(s):  
R. Hamdan ◽  
D. D. Mara
Keyword(s):  
Nitrogen Removal ◽  
Ammonium Nitrogen ◽  
Horizontal Flow ◽  
Vertical Flow ◽  
Stabilization Pond ◽  
Waste Stabilization Pond ◽  
Nitrate N ◽  
N Removal ◽  
Ammonium N ◽  
Waste Stabilization

Rock filters are an established technology for polishing waste stabilization pond effluents. However, they rapidly become anoxic and consequently do not remove ammonium-nitrogen. Horizontal-flow aerated rock filters (HFARF), developed to permit nitrification and hence ammonium-N removal, were compared with a novel vertical-flow aerated rock filter (VFARF). There were no differences in the removals of BOD5, TSS and TKN, but the VFARF consistently produced effluents with lower ammonium-N concentrations (<0.3 mg N/L) than the HFARF (0.8−1.5 mg N/L) and higher nitrate-N concentrations (24–29 mg N/L vs. 17–24 mg N/L).

scholarly journals Ammonium-Nitrogen (NH4+-N) Removal from Groundwater by a Dropping Nitrification Reactor: Characterization of NH4+-N Transformation and Bacterial Community in the Reactor

Water ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 599 ◽  
Author(s):  
Amit Kumar Maharjan ◽  
Tatsuru Kamei ◽  
Iswar Man Amatya ◽  
Kazuhiro Mori ◽  
Futaba Kazama ◽  
...  
Keyword(s):  
Atmospheric Oxygen ◽  
Low Cost ◽  
Ammonium Nitrogen ◽  
Nitrogen Transformation ◽  
Contaminated Groundwater ◽  
Nylon Thread ◽  
N Removal ◽  
Functional Bacteria ◽  
Synthetic Groundwater

A dropping nitrification reactor was proposed as a low-cost and energy-saving option for the removal of NH4+-N from contaminated groundwater. The objectives of this study were to investigate NH4+-N removal performance and the nitrogen removal pathway and to characterize the microbial communities in the reactor. Polyolefin sponge cubes (10 mm × 10 mm × 10 mm) were connected diagonally in a nylon thread to produce 1 m long dropping nitrification units. Synthetic groundwater containing 50 mg L−1 NH4+-N was added from the top of the hanging units at a flow rate of 4.32 L day−1 for 56 days. Nitrogen-oxidizing microorganisms in the reactor removed 50.8–68.7% of the NH4+-N in the groundwater, which was aerated with atmospheric oxygen as it flowed downwards through the sponge units. Nitrogen transformation and the functional bacteria contributing to it were stratified in the sponge units. Nitrosomonadales-like AOB predominated and transformed NH4+-N to NO2−-N in the upper part of the reactor. Nitrospirales-like NOB predominated and transformed NO2−-N to NO3−-N in the lower part of the reactor. The dropping nitrification reactor could be a promising technology for oxidizing NH4+-N in groundwater and other similar contaminated wastewaters.

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.

Performance evaluation of wastewater treatment using horizontal subsurface flow constructed wetlands optimized by micro-aeration and substrate selection

2015 ◽  
Vol 71 (9) ◽  
pp. 1317-1324 ◽  
Author(s):  
Fei Zhong ◽  
Juan Wu ◽  
Yanran Dai ◽  
Dongfang Xiang ◽  
Shuiping Cheng ◽  
...  
Keyword(s):  
Constructed Wetlands ◽  
Sewage Treatment ◽  
Subsurface Flow ◽  
Oxygen Demand ◽  
Ammonium Nitrogen ◽  
Domestic Sewage ◽  
Substrate Selection ◽  
N Removal ◽  
Horizontal Subsurface Flow ◽  
The Individual

The effects of micro-aeration and substrate selection on domestic sewage treatment performance were explored using three pairs (with or without micro-aeration) of horizontal subsurface flow (HSSF) constructed wetlands (CWs) filled with zeolite, ceramsite or quartz granules. The individual and combined effects of micro-aeration and substrate selection on the purification performance of the experimental-scale HSSF CWs were evaluated. The results showed that micro-aeration significantly increased the treatment efficiencies for chemical oxygen demand, total nitrogen, total phosphorus (TP), ortho-phosphate (PO43−-P) and ammonium nitrogen (NH4+-N) using HSSF CWs, while the substrate selection significantly affected the TP, PO43−-P and NH4+-N removal efficiencies (p < 0.05). A two-way analysis of variance (ANOVA) indicated that there was a significant interaction term (i.e. micro-aeration × substrate selection) for NH4+-N removal (p < 0.05). Among the three substrates, ceramsite was the best substrate for the treatment of domestic sewage using HSSF CWs. Therefore, the results of this study suggest that a ceramsite-filled HSSF CW with micro-aeration could be the optimal configuration for decentralized domestic sewage treatment.

On-site and in situ bioremediation of wood-preservative contaminated groundwater

2000 ◽  
Vol 42 (5-6) ◽  
pp. 371-376 ◽  
Author(s):  
J.A. Puhakka ◽  
K.T. Järvinen ◽  
J.H. Langwaldt ◽  
E.S. Melin ◽  
M.K. Männistö ◽  
...  
Keyword(s):  
Iron Oxidation ◽  
Wood Preservative ◽  
Pilot Scale ◽  
High Rate ◽  
Contaminated Groundwater ◽  
Groundwater Temperature ◽  
In Situ Bioremediation ◽  
Contaminated Aquifer ◽  
Fluidized Bed Process

This paper reviews ten years of research on on-site and in situ bioremediation of chlorophenol contaminated groundwater. Laboratory experiments on the development of a high-rate, fluidized-bed process resulted in a full-scale, pump-and-treat application which has operated for several years. The system operates at ambient groundwater temperature of 7 to 9°C at 2.7 d hydraulic retention time and chlorophenol removal efficiencies of 98.5 to 99.9%. The microbial ecology studies of the contaminated aquifer revealed a diverse chlorophenol-degrading community. In situ biodegradation of chlorophenols is controlled by oxygen availability, only. Laboratory and pilot-scale experiments showed the potential for in situ aquifer bioremediation with iron oxidation and precipitation as a potential problem.

Sulfur-anchored palm shell waste-based activated carbon for ultrahigh sorption of Hg(II) for in-situ groundwater treatment

2021 ◽  
pp. 125995
Author(s):  
So Yeon Yoon ◽  
Seok Byum Jang ◽  
Kien Tiek Wong ◽  
Hyeseong Kim ◽  
Min Ji Kim ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Groundwater Treatment ◽  
Palm Shell ◽  
Shell Waste

Assessment of clogging in constructed wetlands by saturated hydraulic conductivity measurements

2019 ◽  
Vol 79 (2) ◽  
pp. 314-322 ◽  
Author(s):  
F. Licciardello ◽  
R. Aiello ◽  
V. Alagna ◽  
M. Iovino ◽  
D. Ventura ◽  
...  
Keyword(s):  
Sensitivity Analysis ◽  
Hydraulic Conductivity ◽  
Constructed Wetlands ◽  
Spatial Scales ◽  
Pilot Scale ◽  
Laboratory Scale ◽  
Test Method ◽  
Conductivity Measurements ◽  
Multiple Spatial Scales ◽  
Ks Values

Abstract This study aims at defining a methodology to evaluate Ks reductions of gravel material constituting constructed wetland (CW) bed matrices. Several schemes and equations for the Lefranc's test were compared by using different gravel sizes and at multiple spatial scales. The falling-head test method was implemented by using two steel permeameters: one impervious (IMP) and one pervious (P) on one side. At laboratory scale, mean K values for a small size gravel (8–15 × 10−2 m) measured by the IMP and the P permeameters were equal to 19,466 m/d and 30,662 m/d, respectively. Mean Ks values for a big size gravel (10–25 × 10−2 m) measured by the IMP and the P permeameters were equal to 12,135 m/d and 20,866 m/d, respectively. Comparison of Ks values obtained by the two permeameters at laboratory scale as well as a sensitivity analysis and a calibration, lead to the modification of the standpipe equation, to evaluate also the temporal variation of the horizontal Ks. In particular, both permeameters allow the evaluation of the Ks decreasing after 4 years-operation and 1–1.5 years' operation of the plants at full scale (filled with the small size gravel) and at pilot scale (filled with the big size gravel), respectively.

scholarly journals Plant diversity increases N removal in constructed wetlands when multiple rather than single N processes are considered

2019 ◽  
Vol 29 (7) ◽  
Author(s):  
Yan Geng ◽  
Ying Ge ◽  
Bin Luo ◽  
Zhengxin Chen ◽  
Yong Min ◽  
...  
Keyword(s):  
Constructed Wetlands ◽  
Plant Diversity ◽  
N Removal
Sign in / Sign up

Export Citation Format

Share Document