scholarly journals Technical-economical analysis of selected decentralized technologies for municipal wastewater treatment in the city of Rome

2010 ◽  
Vol 62 (6) ◽  
pp. 1371-1378 ◽  
Author(s):  
Renato Gavasci ◽  
Agostina Chiavola ◽  
Massimo Spizzirri

Several wastewater treatment technologies were evaluated as alternative systems to the more traditional centralized continuous flow system to serve decentralized areas of the city of Rome (Italy). For instance, the following technologies were selected: (1) Constructed wetlands, (2) Membrane Biological Reactor, (3) Deep Shaft, (4) Sequencing Batch Reactor, and (5) Combined Filtration and UV-disinfection. Such systems were distinguished based on the limits they are potentially capable of accomplishing on the effluent. Consequently, the SBR and DS were grouped together for their capability to comply with the standards for the discharge into surface waters (according to the Italian D.Lgs. 152/06, Table 1, All. 5), whereas the MBR and tertiary system (Filtration + UVc-disinfection) were considered together as they should be able to allow effluent discharge into soil (according to the Italian D.Lgs. 152/06, Table 4, All. 5) and/or reuse (according to the Italian D.M. 185/03). Both groups of technologies were evaluated in comparison with the more common continuous flow treatment sequence consisting of a biological activated sludge tank followed by the secondary settlement, with final chlorination. CWs were studied separately as a solution for decentralized urban areas with limited population. After the analysis of the main technical features, an economical estimate was carried out taking into account the investment, operation and maintenance costs as a function of the plant's capacity. The analysis was based on real data provided by the Company who manages the entire water system of the City of Rome (Acea Ato 2 S.p.A.). A preliminary design of the treatment plants using some of the selected technologies was finally carried out.

2010 ◽  
Vol 2010 ◽  
pp. 1-10 ◽  
Author(s):  
Yong Qiu ◽  
Han-chang Shi ◽  
Miao He

Surface water environment in China was degraded rapidly in the last two decades, resulting in increasingly tighten criteria issued for municipal wastewater treatment plants (WWTPs). This paper reviewed the recent advances of process design and operational optimization for nutrients removal. Three major processes, as anaerobic-anoxic-oxic (AAO) process, oxidation ditch (OD), and sequencing batch reactor (SBR) occupied 65% of WWTPs amounts and 54% of treatment volumes of China in 2006. However conservative process designs and operational faults often impaired the process performances and energy efficiency. Therefore, typical processes were modified, combined, and innovated to meet the requirements of the diverse influent characteristics and lower energy consumptions. Furthermore, operational optimization techniques by modeling, simulation, and real-time control were also developed and applied in China to improve the process operation. Although great efforts had been contributed to improve the WWTPs performances in China, attentions should be continuously paid to the introduction, instruction, and implementation of advanced techniques. At last, the technical demands and appropriated techniques of WWTPs in China were briefly discussed.


Vestnik MGSU ◽  
2019 ◽  
pp. 589-602 ◽  
Author(s):  
Tran Ha Quan ◽  
Elena S. Gogina

Introduction. Vietnamese urban municipal wastewater treatment plants are mainly of aeration-type facilities. Nowadays, an aeration-type plant, the Sequencing Batch Reactor (SBR), is widely applied and possesses a number of advantages over traditional systems with suspended activated sludge. Advantages of the SBR are mainly concluded in simplicity of operation, occupied area and cost. There is a number of problems at the wastewater treatment plants; they are connected with supplying only a half of wastewater design amount for the treatment as well as with quality of the purified water that must satisfy requirements of the Vietnamese discharge standard, the Standard A. Therefore, reconstruction and modification of the SBR is the major challenger to ensure the sustained development of large Vietnamese cities and maintenance of ecological balance. Materials and methods. To enhance the efficiency of wastewater purification in the SBR, the experiments were set on reactor reconstruction and modification by two directions: (1) Technological method, i.e. applying the Biochip 25 biocarrier, and (2) Operation method, i.e. adding the anoxic phase in reactor operation cycle. Laboratory tests were conducted for each of the directions, including comparison of a typical reactor with the modified one. Results. The study resulted in obtaining an optimal amount of the BioChip biocarrier material (10 to 20 %) that increased efficiency of wastewater purification by 10 to 20 %. In addition to this, when creating an anoxic phase of the operation cycle, efficiency of nitrogen removal increased by 20 %. When the denitrification occurs under the anoxic conditions, it contributes to stabilization of ammonium nitrogen removal for daily nitrogen loading in reactor of 0.3 to 0.8 TKN kg/sludge kg. Conclusions. The suggested technology provides the quality of treated water corresponding with the Vietnamese Standard A requirements. At the present, it is planned to proceed with the experiment on the base of Vietnamese semi-industrial plant for research and appraisal of the SBR reconstruction and modification method. Acknowledgements. The authors are grateful to AKVA Control company in Samara for granted biocarrier Mutag BioChip 25 and to Associate Professor Tran Van Quang and his students, Nguyen Ngoc Phuong and Truong Quoc Dai, of Environment Protect Research Center, Danang University for support of the experiment.


PLoS ONE ◽  
2017 ◽  
Vol 12 (6) ◽  
pp. e0178837 ◽  
Author(s):  
Yunlong Yang ◽  
Linxiang Xie ◽  
Xin Tao ◽  
Kaihui Hu ◽  
Shaobin Huang

Membranes ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 421
Author(s):  
Dimitra C. Banti ◽  
Michail Tsangas ◽  
Petros Samaras ◽  
Antonis Zorpas

Membrane bioreactor (MBR) systems are connected to several advantages compared to the conventional activated sludge (CAS) units. This work aims to the examination of the life cycle environmental impact of an MBR against a CAS unit when treating municipal wastewater with similar influent loading (BOD = 400 mg/L) and giving similar high-quality effluent (BOD < 5 mg/L). The MBR unit contained a denitrification, an aeration and a membrane tank, whereas the CAS unit included an equalization, a denitrification, a nitrification, a sedimentation, a mixing, a flocculation tank and a drum filter. Several impact categories factors were calculated by implementing the Life Cycle Assessment (LCA) methodology, including acidification potential, eutrophication potential, global warming potential (GWP), ozone depletion potential and photochemical ozone creation potential of the plants throughout their life cycle. Real data from two wastewater treatment plants were used. The research focused on two parameters which constitute the main differences between the two treatment plants: The excess sludge removal life cycle contribution—where GWPMBR = 0.50 kg CO2-eq*FU−1 and GWPCAS = 2.67 kg CO2-eq*FU−1 without sludge removal—and the wastewater treatment plant life cycle contribution—where GWPMBR = 0.002 kg CO2-eq*FU−1 and GWPCAS = 0.14 kg CO2-eq*FU−1 without land area contribution. Finally, in all the examined cases the environmental superiority of the MBR process was found.


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.


2014 ◽  
Vol 1030-1032 ◽  
pp. 387-390
Author(s):  
Chun Di Gao ◽  
Shi Xin Fan ◽  
Er Long Jiao ◽  
Hao Li ◽  
Wei Xiao Wang

A novel alternating oxic-anoxic operation mode of shortcut nitrification-denitrification was developed in a sequencing batch reactor at ambient temperature. Operational parameters favorable for maintaining the shortcut nitrification-denitrification were investigated and optimized. The experiments showed that alternating oxic-anoxic shortcut nitrification-denitrification system was able to be an independent treatment process in domestic wastewater treatment. And the optimization approach was so efficient that the main pollutant discharge targets achieved Standard A of the first class in "Discharge standard of pollutants for municipal wastewater treatment plant". Moreover, the reliability of the operation strategy in this experimentation was proved, which indicated the excellent nitrogen removal performances.


2014 ◽  
Vol 49 (1) ◽  
pp. 23-31 ◽  
Author(s):  
Antonette Arvai ◽  
Gary Klecka ◽  
Saad Jasim ◽  
Henryk Melcer ◽  
Michael T. Laitta

The Great Lakes and their connecting channels form the largest fresh surface water system on earth. Over the past 10 years, focus on environmental monitoring has shifted to an array of recently discovered compounds known as ‘chemicals of emerging concern’ (CEC). These chemicals are found in products used daily in households, businesses, agriculture and industry, such as flame retardants, pharmaceuticals, personal care products, and pesticides. Wastewater treatment plants are among the important pathways by which CEC enter the Great Lakes, with concentrations highest in the vicinity of wastewater discharges. Treated sewage is often discharged into the nearshore waters, which also provide a source of drinking water to the public. In 2009–2011, the International Joint Commission addressed the need to assess the effectiveness of existing wastewater treatment technologies in the basin to remove CEC, as well as to gain insight on potential advanced technologies to improve their removal. This assessment encompassed three major activities, development of an inventory of municipal wastewater treatment plants that discharge in the basin; a survey of detailed operational data for selected wastewater facilities; and a comprehensive literature review and analysis of the effectiveness of various wastewater treatment technologies to remove chemicals of emerging concern.


2014 ◽  
Vol 9 (2) ◽  
pp. 235-242 ◽  
Author(s):  
S. Morling ◽  
A. Franquiz ◽  
J. Måhlgren ◽  
Å. Westlund

A biological wastewater treatment plant, Nynäshamn treating municipal wastewater and septic sludge operated with a combination of sequencing batch reactor (SBR) units and constructed wetland is presented in this paper. The plant has to treat low temperature wastewater in winter time, still with demands for a biological nitrogen removal. Treatment results from a 13 year operation period are presented. Special attention was given to the nutrient removal during low temperature conditions. The combination of a SBR system along with classical chemical precipitation and a polishing step based on ‘natural’ extensive treatment has been a sustainable way to keep the discharge levels low. The combined treatment with SBR and the wetland at the Nynäshamn plant has resulted in improved discharge levels typically as follows (annual mean values); BOD7 3 mg/l, to be compared with the formal consent value of &lt;15 mg/l, total P &lt; 0.1 mg/l, to be compared with the formal consent value of &lt;0.5 mg/l and total N 7 mg/l, to be compared with the formal consent value of &lt;15 mg/l. It is also important to underline that the change of process train has resulted in a substantial saving of the precipitant agent for phosphorus removal. The needed dosage is now 50% of the previous dose, before the implementation of the SBR-units.


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