Impact of Organic Matter from Stormwater on Water Quality in an Urban River

Improved step-feed de-nitrification progress combined with biological fluidized bed was introduced in this study. The progress had good performance and capacity of de-nitrification and organic matter. The experiment result showed that the de-nitrification efficiency of the improved biological fluidized bed with step-feed process was higher than the fluidized bed A/O process under the same water quality and the operating conditions. When the influent proportion of each segment was equal, the system showed good nitrogen removal efficiency with the change of influent C/N ratio, HRT and sludge return ratio. The removal rate of TN reached up to 88.2%. It showed that the simultaneous nitrification and de-nitrification phenomenon happened in the aerobic zone. The nitrogen removal mechanism was also studied.

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A study of water quality in an urban river and potential improvement using a prototype instream aerator

Canadian Journal of Civil Engineering ◽

10.1139/l89-056 ◽

1989 ◽

Vol 16 (3) ◽

pp. 308-316 ◽

Cited By ~ 1

Author(s):

C. A. Town ◽

D. S. Mavinic ◽

B. Moore

Keyword(s):

Water Quality ◽

Dissolved Oxygen ◽

Data Base ◽

Chlorophyll A ◽

Late Summer ◽

Urban River ◽

Agricultural Activity ◽

Fish Kills ◽

Low Dissolved Oxygen ◽

Oxygen Levels

Urban encroachment and intensive agricultural activity within the Serpentine–Nicomekl watershed (near Vancouver, B.C.) have caused a series of fish (salmon) kills on the Serpentine River since 1980. Low dissolved oxygen was responsible for these kills. This field project investigated some of the dynamic chemical and biological relationships within the river, as well as the use of an instream aerator as a temporary, in situ, water quality improvement measure. Weekly sampling for a 6-month period during the latter half of 1985 established a solid data base for deriving and interpreting meaningful interrelationships. A strong correlation between chlorophyll a and dissolved oxygen levels before the algae die-off supported the hypothesis that algae blooms dying in the fall could create a serious oxygen demand. Because of these environmental conditions, the river is unable to sustain healthy dissolved oxygen levels during this period. As such, a prototype, 460 m artificial aeration line was designed, installed, and monitored to evaluate its potential for alleviating low dissolved oxygen conditions and improving overall water quality during the critical fall period.The instream aerator ran continuously for over 2 months, starting in September 1985. Despite better-than-expected weather conditions (i.e., cool, wet weather) and relatively high dissolved oxygen levels during the fall of 1985, the data base appeared to support the use of this prototype aeration unit as a means of "upgrading" a stretch of an urban river subject to periodic, low dissolved oxygen levels. As a result, a 2-year follow-up study and river monitoring was initiated. In both 1986 and 1987, late summer and early fall river conditions resulted in the potential for serious salmon kills, due to higher-than-normal river temperatures and very low dissolved oxygen. In both instances, the instream aerator prevented such fish kills in a key stretch of the river. Expansion of the system to include other critical stretches of the Serpentine and other urban river systems, near Vancouver, is being considered. Key words: algae, aerator, chlorophyll a, eutrophic, fish kills, instream aeration, river improvement, urban river.

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Effects of Fe addition on sediment P dynamics in a eutrophic lake

10.5194/egusphere-egu21-4941 ◽

2021 ◽

Author(s):

Melanie Münch ◽

Rianne van Kaam ◽

Karel As ◽

Stefan Peiffer ◽

Gerard ter Heerdt ◽

...

Keyword(s):

Water Quality ◽

Organic Matter ◽

Surface Water ◽

Water Column ◽

Sediment Cores ◽

Surface Water Quality ◽

Water Interface ◽

Eutrophic Lakes ◽

Fe Addition

The decline of surface water quality due to excess phosphorus (P) input is a global problem of increasing urgency. Finding sustainable measures to restore the surface water quality of eutrophic lakes with respect to P, other than by decreasing P inputs, remains a challenge. The addition of iron (Fe) salts has been shown to be effective in removing dissolved phosphate from the water column of eutrophic lakes. However, the resulting changes in biogeochemical processes in sediments as well as the long-term effects of Fe additions on P dynamics in both sediments and the water column are not well understood.In this study, we assess the impact of past Fe additions on the sediment P biogeochemistry of Lake Terra Nova, a well-mixed shallow peat lake in the Netherlands. The Fe-treatment in 2010 efficiently reduced P release from the sediments to the surface waters for 6 years. Since then, the internal sediment P source in the lake has been increasing again with a growing trend over the years.In 2020, we sampled sediments at three locations in Terra Nova, of which one received two times more Fe during treatment than the other two. Sediment cores from all sites were sectioned under oxygen-free conditions. Both the porewaters and sediments were analysed for their chemical composition, with sequential extractions providing insight into the sediment forms of P and Fe. Additional sediment cores were incubated under oxic and anoxic conditions and the respective fluxes of P and Fe across the sediment water interface were measured.The results suggest that Fe and P dynamics in the lake sediments are strongly coupled. We also find that the P dynamics are sensitive to the amount of Fe supplied, even though enhanced burial of P in the sediment was not detected. The results of the sequential extraction procedure for P, which distinguishes P associated with humic acids and Fe oxides, as well as reduced flux of Fe(II) across the sediment water interface in the anoxic incubations, suggest a major role of organic matter in the interaction of Fe and P in these sediments.Further research will include investigations of the role of organic matter and sulphur in determining the success of Fe-treatment in sequestering P in lake sediments. Based on these data in combination with reactive transport modelling we aim to constrain conditions for successful lake restoration through Fe addition.

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New Patterns of Temporal and Spatial Variation in Water Quality of a Highly Artificialized Urban River-Course—a Case Study in the Tongzhou Section of the Beiyun River

Water ◽

10.3390/w10101446 ◽

2018 ◽

Vol 10 (10) ◽

pp. 1446 ◽

Cited By ~ 4

Author(s):

Juanhui Ren ◽

Ji Liang ◽

Bo Ren ◽

Xiuqing Zheng ◽

Chaofan Guo

Keyword(s):

Water Quality ◽

Management Practices ◽

Low Impact Development ◽

Urban River ◽

Quality Data ◽

Dominant Factor ◽

Water Runoff ◽

Reclaimed Wastewater ◽

Water Quality Data ◽

Impervious Area

This paper aims to gain a better understanding of urban river pollution through evaluation of water quality. Data for 10 parameters at eight sites of the Tongzhou Section of the Beiyun River (TSBR) are analyzed. Hierarchical cluster analysis, fuzzy comprehensive assessment, discriminant analysis and Spearman’s correlation analysis were used to estimate the water situation of each cluster and analyze its spatial-temporal variations. Principal component analysis/factor analysis were applied to extract and recognize the sources responsible for water-quality variations. The results showed that temporal variation is greater than spatial and sewage discharge is the dominant factor of the seasonal distribution. Moreover, during the rapid-flow period, water quality is polluted by a combination of organic matter, phosphorus, bio-chemical pollutants and nitrogen; during the gentle-flow period, water quality is influenced by domestic and industrial waste, the activities of algae, aquatic plants and phosphorus pollution. In regard to future improvement of water quality in TSBR, the control of reclaimed wastewater from adjacent factories should first be put in place, as well as other techniques, for example, an increase of the impervious area, low-impact development, and integrated management practices should also be proposed in managing storm water runoff.

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Analysis of water pollution and evaluation of purification measures in an urban river basin

Water Science & Technology ◽

10.2166/wst.1996.0297 ◽

1996 ◽

Vol 34 (12) ◽

pp. 33-40 ◽

Cited By ~ 4

Author(s):

Y. Hosoi ◽

Y. Kido ◽

H. Nagira ◽

H. Yoshida ◽

Y. Bouda

Keyword(s):

Water Quality ◽

River Water ◽

River Basin ◽

Urban Areas ◽

River Flow ◽

Sea Water ◽

Water Quality Management ◽

River Water Quality ◽

Urban River ◽

Pollutant Load

The inflow of pollutant load from urban areas and the stagnation of water due to sea water intrusion cause the deterioration of river water quality in tidal zone. In order to improve water quality, various measures such as the reduction of pollutant load by sewage systems, discharge control from sewage treatment plants considering river flow, nutrient removal by aquatic plants, and the dredging of bottom sediments have been examined. The choice of these measures depends on the situation of the river environment and finances. In this study, a field survey was carried out in a typical urban river basin, first. Secondly, on the basis of this survey, a mathematical model was formed to simulate flow and water quality. Several purification alternatives designed for the investigated river basin were comparatively evaluated from the viewpoint of the effect of water quality improvement and their cost. Finally, they were prioritized. Through this case study, a planning process of river water quality management was shown.

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