The nitrogen removal potential of predenitrification systems in sensitive coastal areas

1995 ◽  
Vol 32 (7) ◽  
pp. 135-142
Author(s):  
E. Görgün ◽  
N. Artan ◽  
D. Orhon ◽  
R. Tasli
Keyword(s):  
Water Quality ◽  
Wastewater Treatment ◽  
Nitrogen Removal ◽  
Retention Time ◽  
Treatment Process ◽  
Hydraulic Retention Time ◽  
Domestic Sewage ◽  
Coastal Areas ◽  
Careful Evaluation ◽  
Denitrification Kinetics

Effective nitrogen removal is now required to protect water quality in sensitive coastal areas. This involves a much more difficult treatment process than for conventional domestic sewage as wastewater quantity and quality exhibits severe fluctuations in touristic zones. Activated sludge is currently the most widely used wastewater treatment and may be upgraded as a predenitrification system for nitrogen removal. Interpretation of nitrification and denitrification kinetics reveal a number of useful correlations between significant parameters such as sludge age, C/N ratio, hydraulic retention time, total influent COD. Nitrogen removal potential of predenitrification may be optimized by careful evaluation of wastewater character and the kinetic correlations.

A dispersed-ozone flotation (DOF) separator for tertiary wastewater treatment

2006 ◽  
Vol 53 (9) ◽  
pp. 151-157 ◽  
Author(s):  
P.K. Jin ◽  
X.C. Wang ◽  
G. Hu
Keyword(s):  
Water Quality ◽  
Wastewater Treatment ◽  
Treatment Process ◽  
Hydraulic Retention Time ◽  
Quality Standards ◽  
Tertiary Treatment ◽  
Chlorine Disinfection ◽  
Very High ◽  
Total Bacteria ◽  
Better Than

A dispersed-ozone flotation (DOF) separator was devised for a pilot study of tertiary wastewater treatment for re-use purposes. As a compact device combining coagulation, ozonation and flotation in an integrated unit, the DOF separator achieved a very high removal of SS, TOC, UV254 and colour, as well as effective inactivation of coliform and total bacteria within a short hydraulic retention time of 30 min. The finished water quality is comparable to or better than that by a conventional tertiary treatment process using coagulation, sedimentation, filtration and chlorine disinfection, and meets the quality standards for non-drinkable domestic reuse.

scholarly journals ANALYSIS OF A WETLAND SYSTEM IN THE POST-TREATMENT OF WASTEWATER

2014 ◽  
Vol 3 (1) ◽  
Author(s):  
Carlos Eduardo Zacarkim ◽  
Luciano Caetano De Oliveira ◽  
Nayara Symanski ◽  
Fernando Rodolfo Espinoza Quinõnes ◽  
Soraya Moreno Palácio ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Retention Time ◽  
Treatment Process ◽  
Hydraulic Retention Time ◽  
Low Cost ◽  
Surface Flow ◽  
Wastewater Treatment Process ◽  
Wetland System ◽  
Simple Technology ◽  
Conventional Systems

The study was based on a surface flow wetland system, using the macrophyte Eicchornia crassipes. The use of wetlands as an alternative in the wastewater treatment process has been employed due to the handling and simple technology, addition to the low cost compared to conventional systems. Three hydraulic retention times, they are 4, 6 and 8 days were analyzed. In general the system showed significant results in relation to removals of nutrients for all TRH reviews, where the hydraulic retention time of 6 days achieved the best performance. The proposed system achieved 79.91% reductions for COD, 83.51% of Total Phosphorus, Total Nitrogen 67.93%, 87.7% chromium and 52% Sulfur.

scholarly journals Real Wastewater Treatment Using a Moving Bed and Wastewater-Borne Algal–Bacterial Consortia with a Short Hydraulic Retention Time

Processes ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 116
Author(s):  
Donghan Kang ◽  
Keugtae Kim
Keyword(s):  
Organic Matter ◽  
Wastewater Treatment ◽  
Nitrogen Removal ◽  
Retention Time ◽  
Nutrient Removal ◽  
Hydraulic Retention Time ◽  
Phosphate Removal ◽  
Moving Bed ◽  
Bacterial Consortia ◽  
Moving Media

Algal–bacterial consortium is a promising technology, combined with wastewater treatment plants, because algae produce molecular oxygen for nitrification and organic removal and reduce carbon dioxide emissions. However, algal–bacterial consortia based on suspended growth require a relatively long hydraulic retention time (HRT) of 4 d to 6 d for removal of organic matter and nutrients. For the algal–bacterial consortia in a photobioreactor (PBR) containing a moving bed, the organic matter and nutrient removal and the community structure of algal–bacterial consortia were investigated to determine the performance under a relatively short HRT of 2.5 d. Moving media containing algal–bacterial consortia enhanced the photosynthetic oxygen concentration (0.2 mg dissolved oxygen (DO)·L−1 to 5.9 mg DO·L−1), biochemical oxygen demand removal (88.0% to 97.2%), ammoniacal nitrogen removal (33.8% to 95.3%), total nitrogen removal (61.6% to 87.7%), total phosphate removal (66.4% to 88.7%), algal growth (149.3 mg algae·L−1 to 285.4 mg algae·L−1), and settleability (algae removal efficiency of 20.6% to 71.2%) compared with those of a PBR without moving media (SPBR). Although biomass uptake was the main mechanism for nutrient removal in the SPBR, both biomass uptake and denitrification were the main mechanisms in the PBR with moving media (MBPBR). The bacterial community also changed under the moving media condition. This study shows that moving media might be an essential parameter for PBRs with a short HRT to enhance nutrient removal and settleability.

Bulking and Foaming Organism Control at Phoenix, AZ WWTP

1992 ◽  
Vol 26 (3-4) ◽  
pp. 461-472 ◽  
Author(s):  
O. E. Albertson ◽  
P. Hendricks
Keyword(s):  
Wastewater Treatment ◽  
Nitrogen Removal ◽  
Retention Time ◽  
Oxygen Transfer ◽  
Average Rate ◽  
Oxygen Transfer Efficiency ◽  
Solids Retention ◽  
Total Nitrogen Removal ◽  
The Cost ◽  
The City

A 1630 L/s activated sludge plant at Phoenix was limited to an average rate of 1050 L/s and operated, at 400-600 mg/L MLSS and 0.8-1.3 day solids retention time (SRT) due to bulking sludge and limited clarification capacity. Higher SRTs also produced uncontrolled Nocardia foaming and low dissolved oxygen due to partial nitrification. The City retained the services of a team of consultants to resolve these problems as well as to upgrade the plant to provide nitrification and total nitrogen removal. An anoxic selector design was implemented within the existing basin and the clarifiers were modified to improve inlet design and sludge transport. The modified advanced wastewater treatment (AWT) plant operating at 1450 L/s has averaged an effluent of 7.6 mg/L BOD5, 8.2 mg/L TSS, 1.3 mg/L NH4N, 4.1 mg/L NO3N and 2.9 mg/L TP. Oxygen transfer efficiency has increased about 80% in the nitrification-denitrification (NdeN) mode. The cost of modification/upgrading to AWT was approximately $730,000 and a 400 L/s increase in hydraulic capacity was realized. Upgrading costs were $5.63/m3 ($0.02/gal.)

Nitrogen removal from poultry slaughterhouse wastewater in anaerobic-anoxic-aerobic combined reactor: Integrated effect of recirculation rate and hydraulic retention time

2022 ◽  
Vol 303 ◽  
pp. 114162
Author(s):  
Carla Limberger Lopes ◽  
Tatiane Martins de Assis ◽  
Fernando Hermes Passig ◽  
Adriana Neres de Lima Model ◽  
Juliana Bortoli Rodrigues Mees ◽  
...  
Keyword(s):  
Nitrogen Removal ◽  
Retention Time ◽  
Hydraulic Retention Time ◽  
Slaughterhouse Wastewater ◽  
Recirculation Rate

scholarly journals Treatment Of Tofu Industry Wastewater Using Bioreactor Anaerobic-Aerobic And Bioball As Media With Variation Of Hidraulic Retention Time

REAKTOR ◽  
2019 ◽  
Vol 19 (1) ◽  
pp. 18-25
Author(s):  
Ariani Dwi Astuti ◽  
Dewi Intania Ayu
Keyword(s):  
Wastewater Treatment ◽  
Removal Efficiency ◽  
Retention Time ◽  
Hydraulic Retention Time ◽  
Negative Impact ◽  
Low Cost ◽  
Industrial Effluent ◽  
Organic Loading Rate ◽  
High Concentration ◽  
Small Industries

Tofu which is made by grinding soy bean, generates huge amount of wastewater and thus considered as one of the most polluted food-industrial effluent owing to its high values of organic contents. The small industries of tofu preparation process release the wastewater directly into the water body without being treated first. Prior to discharge this wastewater into the waterbody, the wastewater must be treated to reduce the possibility of negative impact and the contamination of the waterbody. For these small industries, the best alternative of wastewater treatment is one which has the following criteria: easy in operation, low cost operation, low volumes of sludge produced, and can be used in high concentration wastewater. In this research, bioreactor anaerobic-aerobic with media bioball is used. The highest removal efficiency of COD took place in anaerobic zones. Bioreactors were operated with the variations of retention time at 24 hours, 18 hours, and 12 hours. The COD removal efficiency for Hydraulic Retention Time (HRT) of 24 hours, 18 hours and 12 hours were found 90.3% (organic loading rate is 15.1 kg COD/m3.day), 84.4% and 76.3% respectively. The experiment showed that the longer of the hydraulic retention time (HRT), the higher the removal efficiency could be achieved. These occurred because a longer HRT will extend the contact time between wastewater and microorganisms attached. Therefore, microorganisms have a longer time to degrade organic matter in wastewater. Although the removal efficiency in these three-HRT was found high, the effluent of the reactor was still above the effluent standard based on regulation of Ministry of Environmental Permen LH No. 5/2014. Kinetics using Eckenfelder Equation results R2 equal to 0.9991, n equal to 0.293 and K equivalent to 7.3577 mg/L. Keywords: tofu wastewater, anaerobe, aerobe, bioball, wastewater, treatment, attached growth

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