Investigation of the Treatment of Wastewater Using Activated Sludge Process

2012 ◽  
Vol 260-261 ◽  
pp. 969-976
Author(s):  
Ayo Samuel Afolabi ◽  
Oluwagbenga Johnson ◽  
Ambali Saka Abdulkareem ◽  
Bada Samson Oluwaseyi

The treatment of wastewater with activated sludge process has been received with a great attention for decades. However, the effective application of this field is not as widely spread. In this study, the treatment of wastewater was investigated, and samples were collected and ascertained. The process operation was monitored and major observation and findings were noted. Consistent pH of 7.4 was almost maintained. High nutrients removal efficiency was sustained with low concentration of nitrates and phosphates in effluent wastewater. Suspended solids removal was satisfactory, although undesired spike of 19 mg/l and three undesired values beyond >15mg/l were measured. The micronutrient metals such as Al and Zn were found to be high with highest concentration of 113600 mg/kg and 940 mg/kg. The maximum concentration of 300 mg/kg and 332 mg/kg of Mn and Cr respectively were recorded.

2020 ◽  
Vol 12 (17) ◽  
pp. 7196 ◽  
Author(s):  
Salvatore Falco ◽  
Giuseppe Brunetti ◽  
Giovanna Grossi ◽  
Mario Maiolo ◽  
Michele Turco ◽  
...  

At the outlet of the Vermicelli catchment—a peri-urban area located in the campus of University of Calabria (Cosenza, Southern Italy)—a sedimentation tank is located, aiming at collecting the basin surface runoff and improve its quality. First, experimental results of the treatment effects are here presented and analyzed. In addition, a monitoring campaign was conducted in order to characterize the particles transported by surface runoff and to determine the treatment efficiency of the tank. The analysis showed the presence of a pollutant load in the surface runoff of the Vermicelli basin and provided information on its particle-size distribution (PSD). Results were considered in terms of the treatment efficiency of the sedimentation tank, showing a good overall removal efficiency value, together with a high variability of the removal sedimentation efficiency. This variability is mainly due to the different grain size of the suspended solids and the characteristics of the rainfall event.


2000 ◽  
Vol 41 (4-5) ◽  
pp. 245-251 ◽  
Author(s):  
P. Castilla ◽  
M. Meraz ◽  
O. Monroy ◽  
A. Noyola

Low concentration synthetic and municipal wastewaters were treated at HRT as short as 3 and 0.6 h respectively in an anaerobic inverse fluidized bed. Both bioreactors showed gas hold up due to the liquid downflow pattern of the prototype. The bioreactor operated at 3 h had a removal efficiency of 83%, specific activity of 4.5 kg CODremoved/kg IVS (d and the gas hold up varied from 23 to 55%. The reactor treating municipal wastewater had a removal efficiency of 44% when operating at 0.6 h, the specific activity was 4.2 kg CODremoved/kg IVS (d and no biogas was detected apparently because an important fraction was dissolved in the liquid phase. The biomass concentration was 13.8 and 1.1 kg IVS/m3 for synthetic and municipal wastewater and the SEM microphotographs showed a bacterial diversity for the first run and only cocci cells for the second run. The system does not remove suspended solids, so a polishing postreatment to improve water quality has to be implemented.


1988 ◽  
Vol 20 (4-5) ◽  
pp. 143-152 ◽  
Author(s):  
M. Tendaj-Xavier ◽  
J. Hultgren

Bromma sewage treatment plant is the second largest plant in Stockholm with a design flow of 160,000 m3/d. The wastewater is treated mechanically, chemically by pre-precipitation with ferrous sulphate, and biologically by the activated sludge process. The requirements for the plant are 8 mg BOD7/l, 0.4 mg P/l and 2 mg NH4+-N/l. The requirement for ammonia refers to the period July-October. In order to meet those rather stringent requirements, the biological step was expanded 3 years ago with 6 new sedimentation tanks. The 6 new tanks have the same area as the 6 old ones but they have only a depth of 3.7 m compared with the depth of the old tanks, 5.7 m. Experience from the first years of operation of the new tanks is that these tanks are more sensitive and less efficient than the older ones. It seems that the effluent suspended solids concentration from the old tanks is less influenced by rapid flow variations than the concentration in the effluent from the new secondary sedimentation tanks. During the nitrification period denitrification takes place to some degree in the secondary sedimentation tanks. This may cause loss of solids and it has been observed that the deeper old tanks usually produce an effluent of better quality and seem to be less influenced by denitrification than the new ones.


2013 ◽  
Vol 807-809 ◽  
pp. 694-698
Author(s):  
Rong Xin Huang ◽  
Zhen Xing Wang ◽  
Gang Liu ◽  
Qi Jin Luo

In order to guarantee the reliability and security of reclaiming water, research on the removal efficiency of the environmental endocrine chemicals (EDCs) --the Phthalate Esters (PAEs) in conventional secondary activated sludge and wastewater reclamation and reuse process was undergoing at Harbin wastewater treatment plant (WWTP). The wastewater samples were colleted from every unit effluent of WWTP. The results showed that contamination of EDCs were presented in municipal wastewater at Harbin and the concentrations of the four PAEs were 21.01μg/L for Di-n-butyl Phthalate (DBP); 9.63μg/L for Di-n-octyl Phthalate (DnOP); 4.56μg/L for Diethyl Phthalate (DEP); 1.96μg/L for Dimethyl Phthalate (DMP) respectively in the influent. The conventional activated sludge has good removal efficiencies performance on DMP, DEP and DBP. With the increasing of molecular weight and branch chains of PAEs contaminations, the removal rate of the four PAEs in the conventional activated sludge process decreased from 99.82%(DMP),90.60%(DEP),90.10%(DBP) to the only 45.13% removal rate for DnOP, which was mostly removed from primary treatment but no from secondary activated sludge process; Coagulation-air flotation plus filtration process was not a feasible way to remove PAEs from reclaiming treatment units.


2012 ◽  
Vol 610-613 ◽  
pp. 331-336
Author(s):  
Yuan Hua Xie ◽  
Tong Zhu ◽  
Xiao Jiang Liu ◽  
Hui Liu ◽  
Jin Han

An anoxic-oxic activated sludge process (AOASP) was carried out to degrade nonylphenol polyethoxylates (NPEOs). The carbon source in influent was replaced stepwise by a mixture of nonylphenol decaethoxylate (M-NP10EO). The 2nd-derivative UV-spectrometry was applied to determine the total amount of M-NP10EO in water samples. Chemical oxygen demand (COD) removal efficiency achieves about 85% under the highest M-NP10EO loading rate, and M-NP10EO removal efficiency is about 80%. Denaturing gradient gel electrophoresis (DGGE) results of activated sludges show that the microbe species decrease but gradually stabilize with the increase of M-NP10EO concentration in influent. Fluorescence in situ hybridization (FISH) results of activated sludges showe that the dominant microflora under the highest M-NP10EO loading rate is β-Proteobacteria (35%), followed by α-Proteobacteria (15%), γ-Proteobacteria (5%) and Actinobateria (4%).


Author(s):  
Niaz Ahmed Memon ◽  
Nisar Ahmed ◽  
Nusrat Jalbani ◽  
Tahira Ayaz ◽  
Razia Bagum ◽  
...  

This study was conducted for the treatment of tannery wastewater and to develop simple design criteria under local conditions. BOD5, COD, total Cr, SO4 2-, S2-, SS, TDS and TS of the influent and effluent were measured to find process efficiency at various mixed liquor volatile suspended solids (MLVSS), dissolved oxygen (DO) and hydraulic detention time. Results of the study demonstrated that an efficiency of above parameters 93.0%, 92.5%, 94.9%, 62.6%, 98.2%, 87.9%, 82.1% and 82.4%, respectively, could be obtained if the activated sludge process (ASP) is operated at the MLVSS concentration of 3500-4500 mg/L, (DO) concentration of 4.1-5.5 mg/L keeping an aeration time of 12 h. 


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