Research Progress: Reduction of Excess Sludge by Ozone in the Sewage Biotreatment Process

2012 ◽  
Vol 610-613 ◽  
pp. 2410-2415
Author(s):  
Ya Feng Nie ◽  
Cai Hong Lu ◽  
Bo Liu ◽  
Xiu Wen Qu ◽  
Xiao Bo Bai

The principle for the reduction of excess sludge by the ozone in the sewage treatment plants (STPs) was introduced and the change of characteristics of the ozonated sludge was analyzed in this paper. Furthermore, the effects of ozonation of activated sludge on the biotical treatment process in the STP were summarized. At last, the applications of this kind of technology in the worldwide range were enumerated and some further research directions were suggested.

1990 ◽  
Vol 22 (7-8) ◽  
pp. 113-121
Author(s):  
W. Maier

In view of the new effluent standards in West Germany, including nitrification and phosphorus elimination, many of the existing sewage treatment plants will have to be rebuilt or expanded. Another demand which will have to be dealt with in the near future is denitrification. Under consideration of the large BOD5-loads which were taken into account when designing the plants, many of them nitrify during the summer or can be easily converted to operate with nitrification. Principles for planning the upgrading of such plants have been laid down in order to achieve the required effluent concentrations. The application of these principles is demonstrated with examples of upgraded plants.


2009 ◽  
Vol 59 (4) ◽  
pp. 779-786 ◽  
Author(s):  
Gopal Chandra Ghosh ◽  
Takashi Okuda ◽  
Naoyuki Yamashita ◽  
Hiroaki Tanaka

The occurrence and elimination of seventeen antibiotics (three macrolides: azithromycin, clarithromycin and roxithromycin; five quinolones: ciprofloxacin, enrofloxacin, levofloxacin, nalidixic acid and norfloxacin; five sulfonamides: sulfadimethoxine, sulfadimizine, sulfamerazine, sulfamethoxazole and sulfamonomethoxine; and others: tetracycline, lincomycin, salinomycin and trimethoprim) were investigated at four full-scale sewage treatment plants in Japan. The highest concentration was recorded for clarithromycin (1,129 to 4,820 ng/L) in influent, followed by azithromycin (160 to 1,347 ng/L), levofloxacin (255 to 587 ng/L) and norfloxacin (155 to 486 ng/L). A vary inconsistence picture was obtained with negative to over 90% removal. Nalidixic acid (53 to100%) exhibited higher removal efficiency followed by norfloxacin (75 to 95%), levofloxacin (40 to 90%), ciprofloxacin (60 to 83%) and enrofloxacin (38 to 74%). Among macrolides, clarithromycin (50 to 88%) and azithromycin (34 to 86%) showed relatively higher removal efficiency than roxithromycin (−32 to 59%). For most of the antibiotics removal efficiency was higher in A2O and AO based secondary treatment process than CAS process. The effect of the antibiotics on bacterial ammonia oxidation determined by oxygen uptake rate presented that there was no significant effect below 0.05 mg/L of each antibiotics. Even at the same concentration, antibiotics in mixed condition had higher inhibition effects than individuals.


RSC Advances ◽  
2017 ◽  
Vol 7 (66) ◽  
pp. 41727-41737 ◽  
Author(s):  
Hebin Liang ◽  
Dongdong Ye ◽  
Lixin Luo

Activated sludge is essential for the biological wastewater treatment process and the identification of active microbes enlarges awareness of their ecological functions in this system.


1994 ◽  
Vol 30 (6) ◽  
pp. 181-184 ◽  
Author(s):  
Bernd Dorias ◽  
Peter Baumann

National and international regulations require a minimum nitrogen removal efficiency of 70% in most public sewage treatment plants. Unlike in activated sludge plants, selective denitrification in trickling filters was not possible until now. Therefore the aim was to employ trickling filter plants for selective denitrification, using innovative technology that involved minimum capital expenditure. For selective denitrification, it is necessary to prevent as much as possible the transfer of oxygen into the trickling filter while feeding the nitrate to be removed, a process similar to upstream denitrification in the activated sludge process. In a test operation conducted in several sewage treatment plants for over a year, the new process with selective denitrification in a covered trickling filter has given successful results. The denitrification efficiency of this system is comparable to that of upstream denitrification in the activated sludge process. Thus, selective denitrification in the trickling filter is a practical alternative to other nitrogen removal processes, while maintaining the established advantages offered by the trickling filter process.


1989 ◽  
Vol 21 (3) ◽  
pp. 119-124 ◽  
Author(s):  
T. Omura ◽  
M. Onuma ◽  
J. Aizawa ◽  
T. Umita ◽  
T. Yagi

The removal of coliform bacteria, enterococcus bacteria, and coliphages in two sewage treatment plants, one using the activated sludge process and the other using a high-rate trickling filter, was investigated over a period of one year. Coliform and enterococcus bacteria were removed with equal efficiency by the two plants, but coliphages were removed more efficiently by the activated sludge process. Experiments on the mechanism of removal revealed that it was mainly due to adsorption on the activated sludge and on the slime in the trickling filter. Die-off of the micro-organisms seemed to play a minor role in the reduction in counts. The treated sewage was disinfected by chlorination prior to discharge into the receiving water. No coliforms were detected in the chlorinated effluents when they had chlorine residuals in the range of 0 to 1.521 mg/l. However, enterococci were detected when chlorine residuals dropped below 0.598 mg/l. Coliphages proved to be the most resistant organisms and they were generally detected throughout the range of chlorine residuals encountered.


1990 ◽  
Vol 22 (7-8) ◽  
pp. 161-170
Author(s):  
I. Sekoulov ◽  
R. Addicks ◽  
J. Oles

Enlargement and/or upgrading of already existing sewage treatment plants will bring problems to design and operation. However, this can be solved even in some complicated configuration of the treatment system, as will be demonstrated. Having an activated sludge system for BOD removal (first stage) followed by a trickling filter for nitrification (second stage), denitrification of the effluent without an external H donator is hard to achieve. In domestic sewage treatment, denitrification is usually carried out with BOD as carbon source. Additionally to the principal question of pre- or post denitrification and the related effects on the effluent quality (BOD, COD, NH4) pre-denitrification in the given case would be highly ineffective and uneconomical (large hydraulic loads). The paper presents a system using thickened sludge from the activated sludge sedimentation as H donator. The sludge has been successfully used to denitrify the trickling filter effluent. For the design of the post-denitrification stage, the necessary volume of sludge could be determined together with the volume of the denitrification reactor. Results of the pilot-plant studies are presented.


2010 ◽  
Vol 62 (3) ◽  
pp. 701-707 ◽  
Author(s):  
M. Majewsky ◽  
T. Gallé ◽  
L. Zwank ◽  
K. Fischer

The influence of activated sludge quality on the co-metabolic biodegradation of three aminopolycarboxyl acids was investigated for a variety of Luxembourg sewage treatment plants. A combination of biodegradation experiments and respirometric techniques are presented as a reliable approach for the estimation of biokinetics and biological xenobiotic degradation rates that allow for identification of governing parameters such as microbial activity and active biomass. Results showed that biokinetics and degradation rates vary greatly between different plants. The fraction of active biomass on the total suspended solids ranged between 16.9 and 53.7%. Xenobiotic biodegradation rates correlated with microbial activity suggesting a relationship with WWTP performance for carbon and nutrient removal. The biokinetic information can be used to increase the prediction accuracy of xenobiotics removal by individual WWTPs.


2017 ◽  
Vol 12 (4) ◽  
pp. 917-926 ◽  
Author(s):  
C. A. L. Chernicharo ◽  
E. M. F Brandt ◽  
T. Bressani-Ribeiro ◽  
V. R. Melo ◽  
F. J. Bianchetti ◽  
...  

Abstract This study aimed at developing a simple tool for improving the management of gaseous emissions in UASB-based sewage treatment plants (STPs), considering different scenarios for the management of sludge, biogas and gaseous emissions (especially sulfide and methane). For small STPs (<10,000 inhab.), simple alternatives for the use of biogas were considered (e.g. for excess sludge hygienization and household usages). For medium- (>10,000; <100,000) and large-scale (>100,000 inhab.) STPs, other biogas uses were considered, such as in sludge dryers, boilers or combined heat and power engines for electricity generation and heat recovery. All these possibilities were grouped in an interactive spreadsheet containing an extensive database of factors that affect gaseous emissions and energy balance in STPs. The tool can be important for decision makers choosing the best gaseous emissions management practices in UASB-based STPs. Carbon footprint should be the main decision factor when evaluating alternatives for the management of gaseous emissions.


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