scholarly journals Technology for Upgrading the Tailwater of Municipal Sewage Treatment Plants: The Efficacy and Mechanism of Microbial Coupling for Nitrogen and Carbon Removal

Water ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 2850
Author(s):  
Yinan Zhang ◽  
Shihuan Lu ◽  
Yuxin Fang ◽  
Kexin Yang ◽  
Jiafeng Ding ◽  
...  

The efficient removal of carbon (COD) and nitrogen (NH3-N) is vital to improving tailwater from municipal wastewater treatment plants. In this study, denitrification and decarburization bacteria with stable removal efficiencies were introduced into a membrane bioreactor (MBR) for 45 days of field experiments in a QJ Wastewater Treatment Plant (Hangzhou, China) to enhance carbon and nitrogen removal. After adding the decarbonization microorganisms into the denitrification reactor, COD removal increased from 31.2% to 80.2%, while compared to the same MBR with only denitrification microorganisms, the removal efficiency of NH3-N was greatly increased from 76.8% to 98.6%. The results of microbial analysis showed that the cooccurrence of Proteobacteria and Bacillus with high abundance and diverse bacteria, such as Chloroflexi, with autotrophic decarburization functions might account for the synchronous high removal efficiency for NH3-N and COD. This technology could provide a reference for industrial-scale wastewater treatment with the goal of simultaneous nitrogen and carbon removal.

2020 ◽  
Vol 15 (1) ◽  
pp. 160-169 ◽  
Author(s):  
Yeshi Cao ◽  
M. C. M. Van Loosdrecht ◽  
Glen. T. Daigger

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.


1996 ◽  
Vol 33 (12) ◽  
pp. 117-126 ◽  
Author(s):  
I. Purtschert ◽  
H. Siegrist ◽  
W. Gujer

In coordination with the EU-guidelines the large wastewater treatment plants in Switzerland have to be extended with enhanced nitrogen removal. Due to the existing plant configuration, the low COD/N ratio and dilute wastewater, denitrification supported by an external carbon source instead of extending the plant may be an interesting and cost effective solution for municipal wastewater treatment. At the wastewater treatment plant Zürich-Werdhölzli different experiments were performed with methanol addition to predenitrification from March to July 1994. The aim of this work was to evaluate the use of methanol as an alternative to plant extension to achieve a higher nitrogen removal efficiency. Therefore, two parallel denitrifying lanes were investigated, one served for methanol addition experiments and the other as a control. The effect of oxygen input into the anoxic zone due to influent, return sludge and mixing was investigated, too. The results show that nitrogen removal efficiency can be substantially increased as compared to the reference lane. The adaptation period for methanol degradation was only a few days and the process was relatively stable. Based on total nitrogen in the inflow, the average denitrification was 55% with methanol addition and 35% without methanol. The yield coefficient YCOD was 0.4 g CODX g−1 CODMe. Due to the small net growth rate of the methanol degraders the denitrification capacity is relatively low and nitrate peak loads cannot be fully denitrified. Hence, methanol as a carbon source requires more or less constant dosing. To prevent nitrate limitation, methanol addition should be controlled by the anoxic nitrate concentrations.


2015 ◽  
Vol 7 (4) ◽  
pp. 449-454 ◽  
Author(s):  
Ernesta Valeikaitė ◽  
Aušra Mažeikienė

In Lithuania centralized municipal wastewater treatment technologies are applied quite effectively, but there is little evidence of the functioning of individual small wastewater treatment plants. The paper presents the small device AT-6, in the city of Vilnius, and the treated sewage results (BDS7, nitrate, ammonium, total nitrogen, total phosphorus and phosphate concentrations). Studies have shown that treated sewage indicators based on ammonium and nitrate ion concentrations are good. These substances are 2–10 times less than it can be in drinking water according to HN 24: 2003. Concentration of phosphates in the treated sewage ranged from 3.57 to 9.33 mg/L and exceeded the indicators, which were compared. The phosphorus environmental aspect is not dangerous, because treated sewage is not discharged into surface water bodies. Dealing from the pattern of biological indicators and enzymatic activity, the quality of activated sludge is good. Treated sewage does not impair the natural state. Lietuvoje centralizuoto buitinių nuotekų valymo technologijos yra taikomos gana efektyviai, tačiau beveik nėra duomenų, kaip veikia maži individualaus buitinių nuotekų valymo įrenginiai. Straipsnyje analizuojami mažu buitinių nuotekų biologinio valymo įrenginiu AT-6 pasiekiami pagrindiniai išvalymo rodikliai (BDS7, nitratų azoto, amonio azoto, bendrojo azoto, bendrojo fosforo ir fosfatų fosforo koncentracijos). Nuotekų išvalymo laipsnis pagal amonio azoto ir nitratų azoto koncentracijas yra aukštas. Šių medžiagų yra 2–10 kartų mažiau, nei gali būti geriamajame vandenyje pagal HN 24:2003. Fosfatų fosforo (PO4-P) koncentracijos išvalytose nuotekose svyravo nuo 3,57 iki 9,33 mg/l ir viršijo rodiklius, su kuriais buvo lygintos. Šis fosforas aplinkosaugainiu aspektu yra nepavojingas, nes nuotekos nėra išleidžiamos į paviršinį vandens telkinį. Sprendžiant iš rastų biologinių indikatorių ir fermentinio aktyvumo, veikliojo dumblo kokybė yra gera. Išvalytos nuotekos nepablogina gamtos būklės.


2012 ◽  
Vol 518-523 ◽  
pp. 2324-2327
Author(s):  
Jun Feng Wu ◽  
Hua Shu Ouyang ◽  
Xian Li Wang

To alleviate the water pollution, the original wastewater treatment process was transformed based on the existing structures. Anaerobic-anoxic-aerobic process (A2/O process) was used as the main process, instead of the original two-stage aeration process (AB process). Pretreatment process and advanced treatment process were strengthened. After transformation, the effluent quality could meet the first class of A standard of the "municipal wastewater treatment plant emission standards" (GB18918-2002) and all the quality indexes of the treated water met the requirements of discharge standard of sewage treatment. The original structures were fully used in this transformation, saving investment, which provided a practical reference for the transformation of the wastewater treatment plants.


2018 ◽  
Vol 45 ◽  
pp. 00054 ◽  
Author(s):  
Bozena Mrowiec

The aim of this paper was to review the literature data regarding the physico-chemical characteristic of plastic pollutants discharged with municipal sewage, the practical possibility of removing microplastic particles from wastewater during different treatment steps in WWTPs and the problem of surface water contamination within them. Microplastics (the size range of 1 nm to < 5 mm), have been recognized as an emerging threat, as well as an ecotoxicological and ecological risk for water ecosystems. Municipal wastewater treatment plants (WWTPs) are mentioned as the main point sources of microplastics in an aquatic environment. Microplastic particles can be effectively removed in the primary treatment zones via solids skimming and sludge settling processes. Different tertiary treatment processes such as: gravity sand filtration, discfilter, air flotation and membrane filtration provide substantial additional removal of microplastics, and the efficiency of wastewater treatment process can be at a removal level of 99.9%. Nevertheless, given the large volumes of effluent constantly discharged to receivers, even tertiary level WWTPs may constitute a considerable source of microplastics in the surface water.


1999 ◽  
Vol 40 (7) ◽  
pp. 55-65 ◽  
Author(s):  
Mohamed F. Hamoda ◽  
Ibrahim A. Al-Ghusain ◽  
Ahmed H. Hassan

Proper operation of municipal wastewater treatment plants is important in producing an effluent which meets quality requirements of regulatory agencies and in minimizing detrimental effects on the environment. This paper examined plant dynamics and modeling techniques with emphasis placed on the digital computing technology of Artificial Neural Networks (ANN). A backpropagation model was developed to model the municipal wastewater treatment plant at Ardiya, Kuwait City, Kuwait. Results obtained prove that Neural Networks present a versatile tool in modeling full-scale operational wastewater treatment plants and provide an alternative methodology for predicting the performance of treatment plants. The overall suspended solids (TSS) and organic pollutants (BOD) removal efficiencies achieved at Ardiya plant over a period of 16 months were 94.6 and 97.3 percent, respectively. Plant performance was adequately predicted using the backpropagation ANN model. The correlation coefficients between the predicted and actual effluent data using the best model was 0.72 for TSS compared to 0.74 for BOD. The best ANN structure does not necessarily mean the most number of hidden layers.


2021 ◽  
Vol 6 (4) ◽  
pp. 244-250
Author(s):  
Serhii Protsenko ◽  
◽  
Mykola Kizyeyev ◽  
Olha Novytska ◽  
◽  
...  

The possibility of increasing the efficiency of municipal wastewater treatment plant (WWTP) operation by changing the flow diagram of biological wastewater treatment in aeration tanks at minimum expenses for their reconstruction is shown in the paper on the example of one of the regional centres of Ukraine. The technology of nitri-denitrification of wastewater according to the flow diagram of the two-stage modified Ludzak-Ettinger process is offered for the considered conditions. The distribution of wastewater flows and internal nitrate recycling between the individual stages of this flow diagram has been optimized in order to minimize the residual content of total nitrogen in the treated effluents. Computer dynamic modelling of biochemical processes has proved the high efficiency and reliability of the flow diagram proposed by the authors.


Water ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 23 ◽  
Author(s):  
Magdalena Łój-Pilch ◽  
Anita Zakrzewska

Nowadays, risk management applies to every technical facility, branch of the economy, and industry. Due to the characteristics of the analyzed wastewater treatment plant and the specificity of the used processes, one must approach different areas individually. Municipal sewage treatment plants are technical facilities; they function as enterprises and are elements of larger systems—water distribution and sewage disposal. Due to their strategic importance for the environment and human beings, it is essential that they are covered by risk management systems. The basic stage of risk management is its assessment. On its basis, strategic decisions are made and new solutions are introduced. Constant monitoring of the operation of a treatment plant allows for assessment of whether actions taken are correct and whether they cause deterioration of the quality of sewage. In our work, we present a method of risk assessment based on historical data for an existing facility and obtained results.


2008 ◽  
Vol 57 (10) ◽  
pp. 1487-1493 ◽  
Author(s):  
S. Lindtner ◽  
H. Schaar ◽  
H. Kroiss

During a six-year period the Austrian Benchmarking System was developed. The main objectives of this benchmarking system are the development of process indicators, identification of best performance and determination of cost reduction potentials. Since 2004 this system is operated via an internet platform and automated to a large extent. Every year twenty to thirty treatment plants use the web-based access to this benchmarking platform. The benchmarking procedure comprises data acquisition, data evaluation including reporting and organised exchange of experience for the treatment plant managers. The process benchmarking method links the real costs with four defined main processes and two support processes. For wastewater treatment plants with a design capacity &gt;100,000 PE these processes are further split up into sub-processes. For each (sub-) process the operating costs are attributed to six cost elements. The specific total yearly costs and the yearly operating costs of all (sub-)processes are related to the measured mean yearly pollution load of the plant expressed in population equivalents (PE110: 110 gCOD/d corresponding to 60 g BOD5/d)). The specific capital costs are related to the design capacity (PE). The paper shows the benchmarking results of 6 Austrian plants with a design capacity &gt;100,000 PE representing approximately 30% of the Austrian municipal wastewater treatment plant capacity.


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