Experimental Study on Activated Sludge Form Sewage Treatment of Different Oxygen Gradient Reactor

2011 ◽  
Vol 374-377 ◽  
pp. 1054-1058
Author(s):  
Xi Tian ◽  
De Jun Bian ◽  
Qing Kai Ren ◽  
Hong Qu ◽  
Li Guo Wan ◽  
...  

It used dissolved oxygen meter to detect dissolved different oxygen concentration within wastewater treatment reactor and analysed reasons for the formation of oxygen concentration gradient. In order to learn more about activated sludge form of different oxygen gradient in the reactor, biological microscope operated in characteristics of microfauna and activated sludge floc in the reactor has been studied. The results showed that Vorticella and Rotifera could grow normally in the high and low regional areas; there are more abundant micro-fauna species in the area of low oxygen, and the microfauna was more mature than those in the area of high oxygen; activated sludge was brown and floc size was small in the areas of high oxygen, activated sludge was black and floc size was big.

1997 ◽  
Vol 35 (6) ◽  
pp. 37-44 ◽  
Author(s):  
Boran Zhang ◽  
Kazuo Yamamoto ◽  
Shinichiro Ohgaki ◽  
Naoyuki Kamiko

Activated sludges taken from full-scale membrane separation processes, building wastewater reuse system (400m3/d), and two nightsoil treatment plants (50m3/d) as well as laboratory scale membrane separation bioreactor (0.062m3/d) were analyzed to characterize membrane separation activated sludge processes (MSAS). They were also compared with conventional activated sludges(CAS) taken from municipal wastewater treatment plants. Specific nitrification activity in MSAS processes averaged at 2.28gNH4-N/kgMLSS.h were higher than that in CAS processes averaged at 0.96gNH4-N/kgMLSS.h. The denitrification activity in both processes were in the range of 0.62-3.2gNO3-N/kgMLSS.h without organic addition and in the range of 4.25-6.4gNO3-N/kgMLSS.h with organic addition. The organic removal activity in nightsoil treatment process averaged at 123gCOD/kgMLSS.h which was significantly higher than others. Floc size distributions were measured by particle sedimentation technique and image analysis technique. Flocs in MSAS processes changed their sizes with MLSS concentration changes and were concentrated at small sizes at low MLSS concentration, mostly less than 60 μm. On the contrary, floc sizes in CAS processes have not much changed with MLSS concentration changes and they were distributed in large range. In addition, the effects of floc size on specific nitrification rate, denitrification rate with and without organic carbon addition were investigated. Specific nitrification rate was decreased as floc size increased. However, little effect of floc size on denitrification activity was observed.


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.


2018 ◽  
Vol 251 ◽  
pp. 06005 ◽  
Author(s):  
Nazira Dzhumagulova ◽  
Ilya Svetkov ◽  
Vladimir Smetanin ◽  
Nguyen Dinh Dap

The purpose of the present research was to enhance the efficiency of biological wastewater treatment through the direct impact on the metabolism of activated sludge. In the course of research, species and quantitative composition of biological community of activated sludge in aeration tanks during wastewater purification process was studied. Comparative analysis was carried out for linen production wastewater and household sewage. Possible application of biological treatment in linen production was evaluated. Proposals were developed on creation of controllable biological treatment facility. In this paper, biological methods are shown to be efficient for household sewage treatment. Comparative analysis was carried out for linen production wastewater and household sewage. Possible application of biological treatment in linen production was evaluated. Proposals were developed on creation of controllable biological treatment facility.


2017 ◽  
Vol 35 (1) ◽  
pp. 141-148 ◽  
Author(s):  
Michał Marzec

AbstractThe reliability of removal of selected contaminants in three technological solutions of the household sewage treatment plants was analysed in this paper. The reliability of the sewage treatment plant with activated sludge, sprinkled biological deposit and hybrid reactor (activated sludge and immersed trickling filter) was analyzed. The analysis was performed using the Weibull method for basic indicators of impurities, BOD5, COD and total suspended solids. The technological reliability of the active sludge treatment plant was 70% for BOD5, 87% for COD and 66% for total suspended solids. In the sewage treatment plant with a biological deposit, the reliability values determined were: 30% (BOD5), 60% (COD) and 67% (total suspended solids). In a treatment plant with a hybrid reactor, 30% of the BOD5and COD limit values were exceeded, while 30% of the total suspended solids were exceeded. The reliability levels are significantly lower than the acceptable levels proposed in the literature, which means that the wastewater discharged from the analysed wastewater treatment plants often exceeds the limit values of indicators specified in currently valid in Poland Regulation of the Minister of Environment for object to 2000 population equivalent.


2002 ◽  
Vol 46 (4-5) ◽  
pp. 117-124 ◽  
Author(s):  
W. Heine ◽  
I. Sekoulov ◽  
H. Burkhardt ◽  
L. Bergen ◽  
J. Behrendt

By the observation and evaluation of the microscopic picture of activated sludge samples it is possible to introduce another biological parameter additional to conventional physico-chemical parameters for the control of biological stages of waste water treatment plants. Considering the fact that parameters like floc size and floc size distribution, structure of the flocs (compact/open), shape of the flocs (round/irregular) allow perceptions of the adjusted operation conditions of the biological stages, evidence for changing operation conditions or threatening operation disturbances can be recognised. This recognition takes place at a very early phase, because the morphology of activated sludge flocs reacts very fast to changing conditions. An automatic image analysis of activated sludge floc pictures would enable the introduction of a new sum parameter to enhance operation control of aeration tanks. By a statistical evaluation of the processed sludge images several parameters can be used to describe the alteration of activated sludge flocs characteristics. With these biological parameters it is possible to detect altered operation conditions or threatening or existing operation problems at an early phase. Thus it is possible to plan suitable countermeasures. Furthermore, the microscopic picture is the only parameter, that gives important information about the structure of the activated sludge flocs and the biozenosis. In comparison with the mainly used physico-chemical parameters, that just give information about the inlet and outlet of the wastewater treatment plants, the microscopic picture is the only parameter that gives information about the biology of the wastewater treatment process. By means of this biological parameter an improved control and regulation of the biological stages of wastewater treatment plants can be obtained.


2021 ◽  
Author(s):  
Pabel Cervantes-Avilés ◽  
Ayman N. Saber ◽  
Abrahan Mora Polanco ◽  
Jurgen Mahlknecht ◽  
Germán Cuevas-Rodríguez

Abstract The imminent arrival of nanoparticles (NPs) to the wastewater treatment plants (WWTP) brings concern about their effects. In this work, the effects of titanium dioxide (TiO2) NPs in the removal of carbon, nitrogen, and phosphorus by activated sludge bioreactors during the treatment of synthetic, raw and filtered wastewater were evaluated. The floc size, compaction of sludge, and morphological interactions between sludge and NPs were also evaluated. The main effect was observed in the ammoniacal nitrogen removal, which was inhibited up to 22% for all types of wastewater in the presence of TiO2 NPs. While nitrite production deficiencies were observed for real wastewaters experiments, nitrate formation was mainly affected for synthetic wastewater. The removal of organic matter was affected by TiO2 NPs in lower level (up to 6%) than nitrogen removal, especially during treatment of raw wastewater. The removal of orthophosphate was improved in presence of NPs 34%, 16% and 55% for synthetic, raw, and filtered wastewater, respectively. The compaction of the sludge was also a positive effect, which enhanced as the concentration of NPs increased without alterations in the floc size for all types of wastewater. Based on TEM and STEM imaging, the main interaction of TiO2 NPs with activated sludge flocs was mainly the adsorption of NPs on the cell membrane. This means that NPs can disrupt the cell membrane during aerobic wastewater treatment. The effects of NPs on macronutrient removal depended on wastewater characteristics. The use of realistic matrices is highly encouraged for ecotoxicological experiments.


Author(s):  
J. Tauber ◽  
B. Flesch ◽  
V. Parravicini ◽  
K. Svardal ◽  
J. Krampe

Abstract Operational data over 2 years from three large Austrian wastewater treatment plants (WWTPs) with design capacities of 4 million, 950,000 and 110,000 population equivalent (PE) were examined. Salt peaks, due to thawing road salt were detected and quantified by electrical conductivity, temperature and chloride measurement in the inflow of the WWTPs. Daily NaCl inflow loads up to 1,147 t/d and PE-specific loads of 0.26–0.5 kg NaCl/(PE · y) were found. To mimic the plants' behaviour in a controlled environment, NaCl was dosed into the inflow of a laboratory-scale activated sludge plant. The influence of salt peaks on important activated sludge parameters such as sludge volume index, settling velocity and floc size were investigated. Influent and effluent were sampled extensively to calculate removal rates. Respiration measurements were performed to quantify activated sludge activity. Particle size distributions of the activated sludge floc sizes were measured using laser diffraction particle sizing and showed a decrease of the floc size by approximately two-thirds. The floc structure was examined and documented using light microscopy. At salt concentrations below 1 g/L, increased respiration was found for autotrophic biomass, and between 1 and 3 g NaCl/L respiration was inhibited by up to 30%.


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