scholarly journals Effect of coagulation and sonication on the dissolved air flotation (DAF) process for thickening of biological sludge in wastewater treatment

2020 ◽  
Vol 7 (1) ◽  
pp. 59-65 ◽  
Author(s):  
Ali Atamaleki ◽  
Mohammad Bagher Miranzadeh ◽  
Gholam Reza Mostafaii ◽  
Hosein Akbari ◽  
Leila Iranshahi ◽  
...  

Background: Dissolved air floatation (DAF) is one of the methods has been used for the sludge thickening in wastewater treatment plants. This study aimed to investigate the effects of coagulation and sonication processes as additional configurations on the efficiency of a lab-scale DAF process for thickening of the biological sludge of an industrial wastewater treatment plant in Kashan, Iran. Methods: The required amounts of sludge samples were collected from a wastewater treatment plant and kept at temperature of 4°C. Variables, such as pressure (3, 5, and 7 atm), flotation time (5 and 10 minutes), ultrasonic irradiation power (0, 75, and 150 W), and presence/absence of Fe-based coagulant were considered on a sequencing batch reactor (SBR) included coagulation, flotation, and sonication processes, respectively. Results: The use of ultrasonic waves led to an insignificant increase in the DAF efficiency (P>0.05), however, the application of coagulant significantly increased the thickening efficiency (P<0.05). The maximum efficiency of the process was achieved at flotation time of 5 min, pressure of 3 atm, and sonication power of 75 W. Conclusion: According to the results, DAF has a proper efficiency for thickening of biological sludge. Coagulation compared to sonication has a greater effect on the efficiency of the process.

2012 ◽  
Vol 66 (8) ◽  
pp. 1684-1690 ◽  
Author(s):  
Russell Yap ◽  
Michael Holmes ◽  
William Peirson ◽  
Michael Whittaker ◽  
Richard Stuetz ◽  
...  

Dissolved air flotation (DAF) incorporating filtration (DAFF) is used at the Bolivar wastewater treatment plant (WWTP) to polish lagoon effluent for reuse. Elevated algal populations are frequently experienced and can lead to increased coagulant requirements and process control issues. Streaming current detectors (SCDs) and a charge demand analyser (CDA) were used to monitor the full-scale plant. This was followed by an optimisation study using a pilot plant with a CDA. It was found that the normal operational charge demand range for DAF at Bolivar was between −46 and −40 μeq L−1. Decreasing the pH of coagulation reduced coagulant consumption and facilitated more sensitive CDA responses to changes in alum dose.


2008 ◽  
Vol 58 (10) ◽  
pp. 1971-1976 ◽  
Author(s):  
J. S. Albuquerque ◽  
J. C. Domingos ◽  
G. L. Sant'Anna ◽  
M. Dezotti

Biosolids production in the activated sludge process generates an additional cost to wastewater treatment plants due to the growing requirements for sludge treatment and disposal. This work focuses on the application of ozonation to reduce sludge production in an industrial wastewater treatment plant. The results show that ozonation was able to promote cell wall rupture, releasing intracellular matter into the liquid medium. This effect was observed by the increase in concentrations of DNA (1.14 to 7.83 mg/L) and proteins (0.5 to 45.602 mg/L) in the liquid phase, when ozonation was applied during 10 min, using 30 mg/L of ozone. Reduction of sludge production was assessed by calculating the observed sludge yield coefficient (Y) in bench-scale continuous experiments conducted with varying proportions of ozonated sludge in the recycle stream and recycle ratios. Reduction of sludge production ranged from 14 to 39%, depending on the experimental conditions. The best result in terms of sludge excess reduction was achieved when 20% of the recycle sludge was ozonated and the recycle ratio was 0.67.


2020 ◽  
Vol 15 (2) ◽  
pp. 142-151
Author(s):  
Peter Lukac ◽  
Lubos Jurik

Abstract:Phosphorus is a major substance that is needed especially for agricultural production or for the industry. At the same time it is an important component of wastewater. At present, the waste management priority is recycling and this requirement is also transferred to wastewater treatment plants. Substances in wastewater can be recovered and utilized. In Europe (in Germany and Austria already legally binding), access to phosphorus-containing sewage treatment is changing. This paper dealt with the issue of phosphorus on the sewage treatment plant in Nitra. There are several industrial areas in Nitra where record major producers in phosphorus production in sewage. The new wastewater treatment plant is built as a mechanicalbiological wastewater treatment plant with simultaneous nitrification and denitrification, sludge regeneration, an anaerobic zone for biological phosphorus removal at the beginning of the process and chemical phosphorus precipitation. The sludge management is anaerobic sludge stabilization with heating and mechanical dewatering of stabilized sludge and gas management. The aim of the work was to document the phosphorus balance in all parts of the wastewater treatment plant - from the inflow of raw water to the outflow of purified water and the production of excess sludge. Balancing quantities in the wastewater treatment plant treatment processes provide information where efficient phosphorus recovery could be possible. The mean daily value of P tot is approximately 122.3 kg/day of these two sources. The mean daily value of P tot is approximately 122.3 kg/day of these two sources. There are also two outflows - drainage of cleaned water to the recipient - the river Nitra - 9.9 kg Ptot/day and Ptot content in sewage sludge - about 120.3 kg Ptot/day - total 130.2 kg Ptot/day.


2007 ◽  
Vol 56 (7) ◽  
pp. 21-31 ◽  
Author(s):  
D. Brdjanovic ◽  
M. Mithaiwala ◽  
M.S. Moussa ◽  
G. Amy ◽  
M.C.M. van Loosdrecht

This paper presents results of a novel application of coupling the Activated Sludge Model No. 3 (ASM3) and the Anaerobic Digestion Model No.1 (ADM1) to assess a tropical wastewater treatment plant in a developing country (Surat, India). In general, the coupled model was very capable of predicting current plant operation. The model proved to be a useful tool in investigating various scenarios for optimising treatment performance under present conditions and examination of upgrade options to meet stricter and upcoming effluent discharge criteria regarding N removal. It appears that use of plant-wide modelling of wastewater treatment plants is a promising approach towards addressing often complex interactions within the plant itself. It can also create an enabling environment for the implementations of the novel side processes for treatment of nutrient-rich, side-streams (reject water) from sludge treatment.


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.


Proceedings ◽  
2018 ◽  
Vol 2 (11) ◽  
pp. 650 ◽  
Author(s):  
Ioanna Zerva ◽  
Ioanna Alexandropoulou ◽  
Maria Panopoulou ◽  
Paraschos Melidis ◽  
Spyridon Ntougias

Wastewater treatment plants (WWTPs) highly contribute to the transmission of antibiotic resistance genes (ARGs) in the environment. In this work, the diversity of ermF, ermB, sul1 and int1-enconding genes was examined in the influent, the mixed liquor and the effluent of a full-scale WWTP. Based on the clones analyzed, similar genotypes were recorded at all process stages. However, distinct genotypes of int1 were responsible for the expression of sul1 and ermF genes in Gammaproteobacteria and Bacteroidetes, respectively. Due to the detection of similar ARGs profiles throughout the biological process, it is concluded that additional treatment is needed for their retention.


2012 ◽  
Vol 428 ◽  
pp. 169-175
Author(s):  
Guo Kai Fu ◽  
Yi Yue Hu ◽  
Zhi Zhang

A reliable model for any wastewater treatment plant is essential in order to provide a tool for predicting its performance and to form a basis for controlling the operation of the process. This would minimize the operation costs and assess the stability of environmental balance. For the multi-variable, uncertainty, non-linear characteristics of the wastewater treatment system, a variable metric chaos optimization neural network (VMCNW) prediction model is established standing on the actual operation data in the wasterwater treatment system. The model overcomes several disadvantages of the conventional BP neural network. Namely:slow convergence, low accuracy and difficulty in finding the global optimum.The results of model calculation show that the predicted value can better match measured value,played a effect of simulating and predicting and be able to optimize the operation status. The establishment of the predicting model provide a simple and practical way for the operation and management in wastewater treatment plant,and have good research and engineering practical value.


2018 ◽  
Vol 85 (3) ◽  
pp. 379-383 ◽  
Author(s):  
Peter Leonard ◽  
Emma Tarpey ◽  
William Finnegan ◽  
Xinmin Zhan

This Research Communication describes an investigation into the viability of an Intermittently Aerated Sequencing Batch Reactor (IASBR) for the treatment of dairy processing wastewater at laboratory-scale. A number of operational parameters have been varied and the effect has been monitored in order to determine optimal conditions for maximising removal efficiencies. These operational parameters include Hydraulic Retention Time (HRT), Solids Retention Time (SRT), aeration rate and cycle length. Real dairy processing wastewater and synthetic wastewater have been treated using three laboratory-scale IASBR units in a temperature controlled room. When the operational conditions were established, the units were seeded using sludge from a municipal wastewater treatment plant for the first experiment, and sludge from a dairy processing factory for the second and third experiment. In experiment three, the reactors were fed on real wastewater from the wastewater treatment plant at this dairy processing factory. These laboratory-scale systems will be used to demonstrate over time that the IASBR system is a consistent, viable option for treatment of dairy processing wastewater in this sector. In this study, the capacity of a biological system to remove both nitrogen and phosphorus within one reactor will be demonstrated. The initial operational parameters for a pilot-scale IASBR system will be derived from the results of the study.


2018 ◽  
Vol 4 (12) ◽  
pp. 1988-1996 ◽  
Author(s):  
Yan He ◽  
Yishuang Zhu ◽  
Jinghan Chen ◽  
Minsheng Huang ◽  
Guohua Wang ◽  
...  

The tense deficiency of available land resources is becoming one of the bottlenecks in dealing with wastewater treatment plant (WWTP) management issues.


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