scholarly journals Global Internal Recirculation Alternative Operation to Reduce Nitrogen and Ammonia Limit Violations and Pumping Energy Costs in Wastewater Treatment Plants

Processes ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 1606
Author(s):  
Ignacio Santín ◽  
Ramon Vilanova ◽  
Carles Pedret ◽  
Marian Barbu

The internal recirculation plays an important role in different areas of the biological treatment of wastewater treatment plants because it has a great influence on the concentration of pollutants, especially nutrients. A usual manipulation of the internal recirculation flow rate is based on the target of controlling the nitrate concentration in the last anoxic tank. This work proposes an alternative for the manipulation of the internal recirculation flow rate instead of nitrate control, with the objective of avoiding limit violations of nitrogen and ammonia concentrations and reducing operational costs. A fuzzy controller is proposed to achieve it based on the effects of the internal recirculation flow rate in different areas of the biological treatment. The proposed manipulation of the internal recirculation flow rate is compared to the application of the usual nitrate control in an already established and published operation strategy by using the internationally known benchmark simulation model no. 2 as a working scenario. The results show improvements with reductions of 59.40% in ammonia limit violations, 2.35% in total nitrogen limit violations, and 38% in pumping energy costs.

1993 ◽  
Vol 28 (10) ◽  
pp. 33-41
Author(s):  
Jes la Cour Jansen ◽  
Bodil Mose Pedersen ◽  
Erik Moldt

Influent and effluent data from about 120 small wastewater treatment plants (100 - 2000 PE) have been collected and processed. Seven different types of plants are represented. The effluent quality and the treatment efficiency have been evaluated. The most common type of plant is mechanical/biological treatment plants. Some of them are nitrifying and some are also extended for chemical precipitation of phosphorus. Constructed wetlands and biological sandfilters are also represented among the small wastewater treatment plants.


2013 ◽  
Vol 68 (9) ◽  
pp. 1932-1939 ◽  
Author(s):  
Vera L. Barbosa ◽  
Richard M. Stuetz

Odours from wastewater treatment plants are comprised of a mixture of various gases with hydrogen sulphide (H2S) often being the dominant constituent. Activated sludge diffusion (ASD) as a biotreatment system for odour abatement has been conducted for over 30 years but has limited broad application due to disagreement in the literature regarding the effect that ASD may have on wastewater treatment performance. The effects of continuous H2S diffusion at 25 ppmv, with weekly peaks of approximately 100 ppmv, on H2S removal efficiency and wastewater treatment performance was evaluated over a 2-month period using an activated sludge pilot plant. H2S removal averaged 100% during diffusion at 25 ppmv, and 98.9% during the 100 ppmv peak periods. A significant increase in mixed liquor volatile suspended solids concentration (P < 0.01) was observed during H2S diffusion, which may be due to an increase in H2S-degrading microorganisms. There was no adverse effect of H2S on nitrification throughout the ASD trials. Ammonia (NH3) removal was slightly better in the test receiving H2S diffusion (87.6%) than in the control (85.4%). H2S diffusion appeared to improve robustness of the AS biomass to operational upsets.


Author(s):  
Ahmad I. Abbas ◽  
Mohammad D. Qandil ◽  
Muhannad R. Al-Haddad ◽  
Mandana S. Saravani ◽  
Ryoichi S. Amano

Wastewater treatment plants (WWTPs) are a significant energy consumer, yet there are several opportunities of implementing on-site power generation systems. Within the treatment process, the high flow rate of effluent is produced and discharged to a nearby water body by gravity. Thus, hydro turbines can be utilized to generate power in such application due to a difference in elevation and high flow rate. This paper presents a case study of introducing a hydro turbine in wastewater treatment plant in Wisconsin and evaluating the power output in addition to determining the energy savings. The wastewater treatment plant considered in this study has an effluent flow rate of 190 MGD (million gallons per day) and elevation difference of 3 meters (10 feet) between the final stage of treatment and the discharge point. Based on the aforementioned parameters; hubless rim-drive Kaplan type hydro turbine (RDT) is the optimal choice to be used in such application. The RDT is designed and optimized by using in-house code. A computational fluid dynamics (CFD) software is applied to evaluate the performance of the proposed model, and the system is simulated through HOMER software to validate the results generated by the CFD. The expected savings is estimated to be 1,564 MWh/year.


2013 ◽  
Vol 67 (5) ◽  
pp. 1051-1057 ◽  
Author(s):  
A. Sobańtka ◽  
H. Rechberger

Extended statistical entropy analysis (eSEA) is used to evaluate the nitrogen (N) budgets of 13 Austrian wastewater treatment plants (WWTPs). The eSEA results are then compared to the WWTPs specific N-removal rates. Among the five WWTPs that achieve a removal rate of 75% the eSEA detects significant differences in the N-performance. The main reason for this is that eSEA considers all N-species and seems to be more discriminating than the N-removal rate. Additionally, the energy consumption and the costs of the mechanical–biological treatment process are related to the N-performance according to the eSEA. The influence of the WWTP size on the energy- and cost-efficiency of the N-treatment is investigated. Results indicate that energy-efficiency does not necessarily coincide with cost-efficiency. It is shown that smaller WWTPs between 22,000 PE (population equivalents) and 50,000 PE can be operated as energy-efficiently as larger WWTPs between 100,000 and 1,000,000 PE. On average, the smaller plants operate less cost-efficiently than the large ones. This research offers a new method for the assessment of the N-performance of WWTPs, and suggests that small WWTPs are not necessarily less energy- and cost-efficient than large ones.


2018 ◽  
Vol 251 ◽  
pp. 03029 ◽  
Author(s):  
Tran Ha Quan ◽  
Elena Gogina ◽  
Tran Van Quang

All around the world, activated sludge is the classical and traditional biological wastewater treatment for municipal and industrial wastewater. With the development of social and technology, the concentration of pollutants has been increased, so the performance of the old wastewater treatment plants not guaranteed. Therefore, upgrade and reconstruction wastewater treatment system becomes the main task of protection environment, especially in the developing countries. Application biofilms in process biological wastewater treatment is one of technology method and it has many advantages. In the Sequencing Batch Reactor, the Mutag BioChip 25TM provides to the bacteria an optimal habitat at the surface area, increasing rate of Utilization of Substrates 20 – 30% and efficiency of organic matter removal from 10 – 15%.


2006 ◽  
Vol 54 (5) ◽  
pp. 51-58 ◽  
Author(s):  
T. Yamaguchi ◽  
Y. Yao ◽  
Y. Kihara

A novel sludge disintegration system (JFE-SD system) was developed for the reduction of excess sludge production in wastewater treatment plants. Chemical and biological treatments were applied to disintegrate excess sludge. At the first step, to enhance biological disintegration, the sludge was pretreated with alkali. At the second step, the sludge was disintegrated by biological treatment. Many kinds of sludge degrading microorganisms integrated the sludge. The efficiency of the new sludge disintegration system was confirmed in a full-scale experiment. The JFE-SD system reduced excess sludge production by approximately 50% during the experimental period. The quality of effluent was kept at quite a good level. Economic analysis revealed that this system could significantly decrease the excess sludge treatment cost.


2019 ◽  
pp. 243-250
Author(s):  
Regimantas Dauknys

This article presents the wastewater treatment in small settlements and rural areas ofLithuania, including descriptions of capacity and loading of wastewater treatment plants(WWTPs), types of treatment facilities, and development trends of biological treatmentfacilities. In 2000 Lithuania had 597 WWTPs with capacity up to 1000 m3/d, 95% of them arethe biological treatment plants. Today the most of these WWTPs are unloaded due to thetendency to centralise wastewater treatment in rural areas of Lithuania that were in the eightand ninth decades.In small settlements and rural areas of Lithuania the aeration facilities are predominant. In theeight and ninth decades practically only the activated sludge systems were built. The situationbegan to change in the last decade of the last century: the biological filters and soil filtrationfacilities with discharge into surface waters were applied more frequently, so the building ofaeration facilities started to decrease.


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