Long-term response of periphyton and macrophytes to reduced municipal nutrient loading to the Bow River (Alberta, Canada)

2002 ◽  
Vol 59 (6) ◽  
pp. 987-1001 ◽  
Author(s):  
Al Sosiak
Keyword(s):  
Nutrient Removal ◽  
Aquatic Macrophytes ◽  
Municipal Wastewater ◽  
Nutrient Loading ◽  
Wastewater Treatment Plants ◽  
Phosphorus Loading ◽  
Potamogeton Pectinatus ◽  
Municipal Wastewater Treatment ◽  
Dissolved Phosphorus ◽  
Nitrite Nitrate

The biomass of periphyton and aquatic macrophytes (Potamogeton vaginatus and Potamogeton pectinatus) in the Bow River was sampled over 16 years to assess the response of these plants to improved phosphorus (1982–1983) and nitrogen removal (1987–1990) at Calgary's two municipal wastewater treatment plants. These improvements in treatment reduced total phosphorus loading to the Bow River by 80%, total ammonia loading by 53%, and nitrite + nitrate loading by 50%. No change in periphytic biomass was detected after enhanced phosphorus removal where total dissolved phosphorus (TDP) in river water remained relatively high (10–33 μg·L–1). However, periphytic biomass declined at sites further downstream with TDP < 10 μg·L–1. Regression analysis predicted that nuisance periphyton biomass (>150 mg·m–2) occurred at TDP > 6.4 μg·L–1 (95% confidence interval: 1.9–7.6 μg·L–1). Macrophyte biomass was inversely correlated with discharge and was lower during high-discharge years. Biomass also declined following enhanced nutrient removal, with the greatest decrease following reduced nitrogen discharge. These results provide the first evidence for a response of periphyton and aquatic macrophytes to enhanced nutrient removal from municipal wastewater.

Expenditure on the operation of municipal wastewater treatment plants for nutrient removal

2000 ◽  
Vol 41 (9) ◽  
pp. 281-289 ◽  
Author(s):  
O. Nowak
Keyword(s):  
Nutrient Removal ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
General Scheme ◽  
Operating Costs ◽  
Municipal Wastewater Treatment ◽  
Wastewater Purification ◽  
Labour Costs ◽  
Municipal Wastewater Treatment Plants ◽  
P Removal

Operating costs of Austrian municipal treatment plants are evaluated for 1989/90 and for 1997, respectively. The results indicate that presently the expenses which can be directly connected to wastewater purification, i.e. energy and chemicals for P removal, comprise only about 20% of the total operating costs. Today, in Austria like in other EU countries, the predominating factor is “labour costs”, even at nutrient removal plants. A general scheme for estimating operating costs is presented that can be applied to WWTPs in other parts of the world. In this scheme the important factors relevant to the operating costs are integrated.

Benchmarks for the energy demand of nutrient removal plants

2003 ◽  
Vol 47 (12) ◽  
pp. 125-132 ◽  
Author(s):  
O. Nowak
Keyword(s):  
Nutrient Removal ◽  
Energy Demand ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Electrical Energy ◽  
Anaerobic Sludge ◽  
Operational Experience ◽  
Municipal Wastewater Treatment ◽  
Sludge Digestion ◽  
Municipal Wastewater Treatment Plants

The energy demand of municipal wastewater treatment plants for nutrient removal equipped with primary clarifiers, activated sludge system, anaerobic sludge digestion, and CHP is evaluated theoretically, on the basis of COD balances. Operational experience from energy-efficient Austrian treatment plants confirms that the demand on external electrical energy can be kept as low as 5 to 10 kWh/(pe.a) depending on the N:COD ratio in the raw wastewater. A low N:COD ratio helps to keep not only the effluent nitrogen load low, but also the energy demand. Measures to minimise the energy demand at treatment plants and to reduce the nitrogen load are discussed.

scholarly journals The bottlenecks and causes, and potential solutions for municipal sewage treatment in China

2020 ◽  
Vol 15 (1) ◽  
pp. 160-169 ◽  
Author(s):  
Yeshi Cao ◽  
M. C. M. Van Loosdrecht ◽  
Glen. T. Daigger
Keyword(s):  
Wastewater Treatment ◽  
Nutrient Removal ◽  
Urban Areas ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Sewage Treatment ◽  
Integrated Design ◽  
Cost Effective ◽  
Municipal Sewage ◽  
Municipal Wastewater Treatment

Abstract Since about the 1990s China has achieved remarkable progress in urban sanitation. The country has built very extensive infrastructure for wastewater treatment, with 94.5% treatment coverage in urban areas and legally mandated nation-wide full nutrient removal implemented. However, municipal wastewater treatment plants (WWTPs) in China are still confronted with issues rooted in the unique sewage characteristics. This study compares energy recovery, cost of nutrient removal and sludge production between Chinese municipal WWTPs and those in countries with longer wastewater treatment traditions, and highlights the cause-effect relationships between Chinese sewage characteristics – high inorganic suspended solids (ISS) loads, and low COD and C/N ratio, and municipal WWTP process performance in China. Integrated design and operation guidelines for municipal WWTPs are imperative in relation to the unique sewage characteristics in China. Cost-effective measures and solutions are proposed in the paper, and the potential benefits of improving the sustainability of municipal WWTPs in China are estimated.

scholarly journals Response of macrobenthic communities to changes in water quality in a subtropical, microtidal estuary (Oso Bay, Texas)

2020 ◽  
Vol 1 ◽  
Author(s):  
Kevin de Santiago ◽  
Terence A. Palmer ◽  
Michael S. Wetz ◽  
Jennifer Beseres Pollack
Keyword(s):  
Wastewater Treatment ◽  
Municipal Wastewater ◽  
Nutrient Loading ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Municipal Wastewater Treatment ◽  
Spatial Changes ◽  
Municipal Wastewater Treatment Plants ◽  
Highly Correlated ◽  
Limited Water Exchange

AbstractThe influence of nutrient loading and other anthropogenic stressors is thought to be greater in low inflow, microtidal estuaries, where there is limited water exchange. This 11-month study compared spatial changes in macrofaunal communities adjacent to regions that varied in land cover in Oso Bay, Texas, an estuarine secondary bay with inflow dominated by hypersaline discharge, in addition to discharge from multiple municipal wastewater treatment plants. Macrofauna communities changed in composition with distance away from a wastewater treatment plant in Oso Bay, with the western region of the bay containing different communities than the head and the inlet of the bay. Ostracods were numerically dominant close to the wastewater discharge point. Macrobenthic community composition is most highly correlated with silicate concentrations in the water column. Silicate is negatively correlated with salinity and dissolved oxygen, and positively correlated with nutrients within the bay. Results are relevant for environmental management purposes by demonstrating that point-source discharges can still have ecological effects in hydrologically altered estuaries.

Removal of ibuprofen from wastewater: comparing biodegradation in conventional, membrane bioreactor, and biological nutrient removal treatment systems

2008 ◽  
Vol 57 (1) ◽  
pp. 1-8 ◽  
Author(s):  
T.M. Smook ◽  
H. Zho ◽  
R.G. Zytner
Keyword(s):  
Nutrient Removal ◽  
Rate Constants ◽  
Membrane Bioreactor ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Aerobic Biodegradation ◽  
Biological Nutrient Removal ◽  
Aeration Tank ◽  
Municipal Wastewater Treatment ◽  
Pharmaceutical Removal

Pharmaceuticals are continually being introduced into the influent of municipal wastewater treatment plants (WWTPs). Developing a better understanding of pharmaceutical removal mechanisms within the different treatment processes is vital in preventing downstream contamination of our water resources. In this study, ibuprofen, a popular over-the-counter pain reliever, was monitored by taking wastewater samples throughout the City of Guelph municipal WWTP. Greater than 95% of ibuprofen was found to be removed in the aeration tank, with aerobic biodegradation being the dominant mechanism. For comparison, first-order kinetics were used to quantify ibuprofen biodegradation in a conventional WWTP aeration tank and in a membrane bioreactor (MBR) pilot plant. The rate constants, kbiol, for the conventional tank and the MBR were determined to be (−6.8±3.3) L/g SS*d and (−8.4±4.0) L/g SS*d, respectively. These two rate constants were found to be statistically similar. Preliminary study of a biological nutrient removal pilot system also suggests that ibuprofen can be anaerobically degraded.

The Introduction of Nitrogen and Phosphorus Removal Technologies for Decreasing Pollution of the Elbe River in Czechoslovakia

1991 ◽  
Vol 24 (10) ◽  
pp. 205-209
Author(s):  
Jirí Wanner ◽  
Miroslav Kos
Keyword(s):  
Nutrient Removal ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Municipal Wastewater Treatment ◽  
Nitrogen And Phosphorus ◽  
Nitrogen And Phosphorus Removal ◽  
Removal Technologies ◽  
Municipal Wastewater Treatment Plants ◽  
Total Capacity ◽  
The Elbe River

A short state-of-the-art-review in nutrient removal technologies is given and problems connected with nutrient removal in the activated sludge process enumerated. The present level of BOD and nutrient load to the Elbe in the Czech Basin and possible means of improvement are discussed. Seven municipal wastewater treatment plants, planned to be built in 1990-2000, are briefly described. The total capacity of these plants represents about 280000 kg BOD5/d and 29000 kg TKN/d.

Removal of micropollutants in municipal wastewater treatment plants by powder-activated carbon

2012 ◽  
Vol 66 (10) ◽  
pp. 2115-2121 ◽  
Author(s):  
M. Boehler ◽  
B. Zwickenpflug ◽  
J. Hollender ◽  
T. Ternes ◽  
A. Joss ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Activated Carbon ◽  
Nutrient Removal ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Full Scale ◽  
Secondary Effluent ◽  
Municipal Wastewater Treatment ◽  
Powder Activated Carbon ◽  
Municipal Wastewater Treatment Plants

Micropollutants (MP) are only partly removed from municipal wastewater by nutrient removal plants and are seen increasingly as a threat to aquatic ecosystems and to the safety of drinking water resources. The addition of powder activated carbon (PAC) is a promising technology to complement municipal nutrient removal plants in order to achieve a significant reduction of MPs and ecotoxicity in receiving waters. This paper presents the salient outcomes of pilot- and full-scale applications of PAC addition in different flow schemes for micropollutant removal in municipal wastewater treatment plants (WWTPs). The sorption efficiency of PAC is reduced with increasing dissolved organic carbon (DOC). Adequate treatment of secondary effluent with 5–10 g DOC m−3 requires 10–20 g PAC m−3 of effluent. Counter-current use of PAC by recycling waste PAC from post-treatment in a contact tank with an additional clarifier to the biology tank improved the overall MP removal by 10 to 50% compared with effluent PAC application alone. A dosage of 15 g PAC m−3 to a full-scale flocculation sand filtration system and recycling the backwash water to the biology tank showed similar MP elimination. Due to an adequate mixing regime and the addition of adapted flocculants, a good retention of the fine fraction of the PAC in the deep-bed filter were observed (1–3 g TSS m−3; TSS: total suspended solids). With double use of PAC, only half of the PAC was required to reach MP removal efficiencies similar to the direct single dosage of PAC to the biology tank. Overall, the application of PAC in WWTPs seems to be an adequate and feasible technology for efficient MP elimination (&gt;80%) from wastewater comparable with post ozonation.

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