Treatment of Polluted River Water Using Surface Flow Constructed Wetlands in Xinyi River Floodplain

2011 ◽  
Vol 396-398 ◽  
pp. 1909-1913
Author(s):  
Jian Qiang Wu ◽  
Min Wang ◽  
Jian Wu ◽  
Hao Tang

Treatment of polluted river water with great variations of water quality using pilot-scale Surface Flow Constructed Wetland (SFW) was studied in this paper. The main results show that: When the influent concentrations of CODMn and NH4+-N were 11.69~60.00 mg•L-1 and 1.37~20.18 mg•L-1, the CODMn and NH4+-N removal rate of SFW which planted Lythrum salicaria, Canna indica, Typha latifolia and Scirpus locustris were 26.44%、40.12%、46.71%、28.23% and 64.27%、70.49%、66.78%、58.52%. Typha latifolia and Canna indica have stronger ability for purifying pollutants. Scirpus locustris has strongest ability of overhead flooding, it can resist inundation over 22 days and still live. Lythrum salicaria has lowest ability of overhead flooding, it only can resist inundation 7 days.

2013 ◽  
Vol 663 ◽  
pp. 1029-1032 ◽  
Author(s):  
Cheng Xin Qin ◽  
Gang He ◽  
Yu Huan Duan ◽  
Xiao Ping Pang ◽  
Zong Lian She

A lab-scale hybrid constructed wetland system was constructed to purify polluted river water. The system was composed of a first stage of the vertical subsurface flow filter, followed by a second stage of horizontal subsurface flow bed. Both beds used furnace slag with a size of 4-60 mm for the main layer. The system was continuously fed. Different depths of unsaturated layer (0 cm, 15 cm and 30 cm) in vertical filter were tested. The unsaturated layer of 30 cm in vertical filter presented the most effective ammonia removal of 89.1%, while lowest NO3--N removal rate of 74.1% for the system. High TN removal efficiencies (77.3%-81.0%) could be observed during operation of three depths. The removals of COD and TP were in the range of 97.1%-98.4% and 76.4%-88.9%, respectively.


2021 ◽  
Vol 13 (22) ◽  
pp. 12456
Author(s):  
Tao Wang ◽  
Liping Xiao ◽  
Hongbin Lu ◽  
Shaoyong Lu ◽  
Xiaoliang Zhao ◽  
...  

The quality of micropolluted water is unstable and its substrate concentration fluctuates greatly. The goal is to predict the concentration effect on the treatment of nitrogen in a river with an actual low C/N ratio for the proposed full-scale Xiaoyi River estuary wetland, so that the wetland project can operate stably and perform the water purification function effectively in the long term. Two pilot-scale multistage constructed wetland–pond (MCWP) systems (S1 and S2, respectively) based on actual engineering with the same “front ecological oxidation ponds, two-stage horizontal subsurface flow constructed wetlands and surface flow constructed wetlands (SFCWs) as the core and postsubmerged plant ponds” as the planned process were constructed to investigate the effect of different influent permanganate indexes (CODMn) and total nitrogen (TN) contents on nitrogen removal from micropolluted river water with a fixed C/N ratio from summer to winter in the field. The results indicate that the TN removal rate in the S1 and S2 systems was significant (19.56% and 34.84%, respectively). During the process of treating this micropolluted water with a fixed C/N ratio, the influent of S2 with a higher CODMn concentration was conducive to the removal of TN. The TN removal rate in S2 was significantly affected by the daily highest temperature. There was significant nitrogen removal efficiency in the SFCWs. The C/N ratio was a major determinant influencing the nitrogen removal rate in the SFCWs. The organic matter release phenomenon in SFCWs with high-density planting played an essential role in alleviating the lack of carbon sources in the influent. This research strongly supports the rule that there is seasonal nitrogen removal in the MCWPs under different influent substrate concentrations, which is of guiding significance for practical engineering.


2001 ◽  
Vol 1 (1) ◽  
pp. 89-96 ◽  
Author(s):  
S.R. Jing ◽  
Y.F. Lin ◽  
D.Y. Lee ◽  
T.W. Wang

The Erh-Ren River is located in southern Taiwan and is one of the most polluted rivers in Taiwan. A pilot-scale constructed wetlands (ERRCW) system containing a free surface flow wetland (FSF) followed by a subsurface flow wetland (SSF) was set up to treat the polluted river water. The system was designed to include solids removal. A removal efficiency of suspended solids (SS) in the ERRCW system that was greater than in a control system indicates that the existence of macrophytes in wetlands could enhance solids removal. The results of this study also showed that SS were removed mainly through the SSF in the ERRCW system. The poor removal of SS, or even an increase in SS, that occurred in the FSF was found to be caused by the growth of algae. Although the macrophytes reduced the penetration of sunlight into the water in the FSF portion of the ERRCW system, the residue of nutrients in water and a low flushing rate still induced the growth of algae on some open water surfaces. From this study, it may be concluded that the roles played by macrophytes in solids removal include providing barriers for filtration, reducing sunlight penetration, supplying oxygen to enhance biodegradation of organic solids, and absorbing nutrients to limit the growth of algae.


2016 ◽  
Vol 287 ◽  
pp. 62-73 ◽  
Author(s):  
Tanveer Saeed ◽  
Biprojit Paul ◽  
Rumana Afrin ◽  
Abdullah Al-Muyeed ◽  
Guangzhi Sun

2006 ◽  
Vol 76 (1) ◽  
pp. 90-97 ◽  
Author(s):  
X. Ruan ◽  
Y. Xue ◽  
J. Wu ◽  
L. Ni ◽  
M. Sun ◽  
...  

2013 ◽  
Vol 295-298 ◽  
pp. 1039-1044 ◽  
Author(s):  
Jian Lei Gao ◽  
Bing Nan Lv ◽  
Yi Xin Yan ◽  
Jian Ping Wu

The pilot-scale Anoxic-Anaerobic-Microaerobic-Aerobic (A2O2) biological nitrogen removal process was used to treat the wastewater from nitrogenous fertilizer production with C/N ratio of 1~2. Batch tests were conducted to investigate the patial nitrification using the activated sludge from the microaerobic tank rich in nitrite bacteria as the experimental object. Results showed that 95% removal efficiency of NH3-N could be obtained with the HRT of 30 h. The SVI affected the NH3-N removal rate and the optimal SVI was 106 mL/g. The ORP was well correlated with the logarithm of NH3-N concentration with the linear regression equation of y=-57.233x+3.308. Moreover, the kinetic model for partial nitrification was determined as v=4.762s/(9.86+s).


2007 ◽  
Vol 56 (3) ◽  
pp. 199-205 ◽  
Author(s):  
D. Paredes ◽  
M.E. Vélez ◽  
P. Kuschk ◽  
R.A. Mueller

Constructed wetlands are used for the treatment of wastewater containing metals. In order to clarify the role of plants, flow and the impact of organic matter, an investigation of three factors, each at two different levels, was carried out in small-scale model wetlands. The evaluated factors and levels were: type of flow (subsurface and surface); presence of plants (planted with Typha latifolia and unplanted) and addition of organic matter (with and without). Eight different experimental units were run for a year. The units were fed with synthetic wastewater containing chromium (VI) (1.5 mg L−1), zinc (1.5 mg L−1), macro, micronutrients and organic matter (to those units in which this factor was being investigated). Subsurface flow wetlands showed a significantly higher rate of chromium removal in comparison with surface flow systems (97 and 60 mg m−2 d−1, respectively). Planted systems removed significantly more chromium compared to unplanted systems (85 and 76 mg m−2 d−1, respectively), and the addition of organic matter increased the removal rate in a comparison with the units without it (88 and 69 mg m−2 d−1, respectively). Similar results were found for zinc; however, the addition of organic matter made no significant difference to zinc removal.


2013 ◽  
Vol 448-453 ◽  
pp. 604-607 ◽  
Author(s):  
Hong Jie Sun ◽  
Xin Nan Deng ◽  
Rui Chen

Research was conducted on pilot-scale, two-stage batch-flow constructed wetland systems for domestic wastewater treatment. Synthetic domestic wastewater was treated in a pre-acidification reactor with a hydraulic retention time (HRT) of 3 hours and the average removal rate of chemical oxygen demand (COD) and ammonia-nitrogen (NH4-N) reached 30% and 13.6%, respectively. The first-stage constructed wetland operated with up-flow and batch feed and drain. One cycle was 12h, including 6h feed and 6h drain. With HRT of 3 days, the effluent COD concentrations fluctuated from 32.5 mg/L to 103.4 mg/L, removal rates varied from 60% to 88%; effluent NH4-N concentrations were in the range of 4.8 mg/L to 10.8 mg/L, removal rates varied from 50% to 70%. The second-stage constructed wetland operated with down-flow, which one cycle was 24h, including 12h feed and 12h drain. With HRT of 1 day, effluent COD concentrations varied from 15.7 mg/L to 48.7 mg/L, removal averaged 53.2%; effluent NH4-N concentrations ranged from 0 mg/L to 0.4 mg/L, average removal exceeded 99%. The spatial variation of COD and NH4-N in the first-stage constructed wetland demonstrated that entrainment of air during draining of constructed wetland could strengthen the removal of COD and NH4-N. Temperature had no significant effect on COD degradation while obviously affected the removal of NH4-N.


2013 ◽  
Vol 726-731 ◽  
pp. 3501-3505 ◽  
Author(s):  
Zhi Gang Zhao ◽  
Yong Xiang Zhang ◽  
Shuo Jia Peng ◽  
Zhi Yuan Li ◽  
Wei Yao Li

Surface flow wetland with Reed planted in it was employed to treat micro-polluted water in Xinkai river, and effects of temperature, hydraulic retention time and growth of plants on the performance of surface flow wetland were studied. The results showed that COD removal of surface flow wetland was influenced by growth of plants and temperature, hydraulic retention time affected the performance of surface flow wetland obviously. NH4+-N removal of surface flow wetland was excellent and stable. Most of the area of the wetland system was under anaerobic or anoxic, Concentration of NO2--N and NO3--N in effluent stayed low. The denitrification was fully conducted but nitrification became a constraining factor. TP removal performance of surface flow wetland was ordinary. When Temperature was greater than 16°C, the hydraulic retention time was greater than the 3d and plants grew well, removal efficiencies of CODNH4+-N and TP were 22.45%,70.10% and 55.80% with concentration below 30.21mg/L1.82mg/L and 0.36mg/L, and the standards of Surface Water Grade V were satisfied.


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