Research on the Treatment of Coal Chemical Wastewater by Activated Sludge Process with Fixed Biological Media Process and Strains

2012 ◽  
Vol 610-613 ◽  
pp. 2006-2011
Author(s):  
Chun Yan Xu ◽  
Hong Jun Han
Keyword(s):  
Activated Sludge ◽  
Stenotrophomonas Maltophilia ◽  
Coal Gasification ◽  
Total Phenol ◽  
Phenol Removal ◽  
Activated Sludge Process ◽  
Biological Media ◽  
Removal Rates ◽  
Term Operation ◽  
N Removal

Full scale two-stage activated sludge process (ASP) with fixed biological media was used to treat coal gasification wastewater. The ASP has operated for more than one year and COD, total phenol and NH4-N removal effects were illuminated. COD and total phenol removal rates were around 85% and 90% during long term operation. Effluent COD and total phenol of the first stage of the ASP had an abnormal increase and turned to normal after several weeks. Nitrification of the ASP increased slowly and NH4-N removal rates achieved 80% after 15 weeks. Stenotrophomonas maltophilia K279a is isolated from coal chemical industry wastewater. The optimum conditions for PO production are phenol 1000mg/L, temperature 30-34 and pH 7-7.5. The strain resists 980mg/L COD and 805mg/L phenols. The degradation rate of phenols reaches 97% in 48h. The results show that Stenotrophomonas maltophilia K279a can be applied to the aerobic process with high proportion of phenols

Improving nitrogen removal in predenitrification-nitrification biofilters

2004 ◽  
Vol 48 (11-12) ◽  
pp. 419-428 ◽  
Author(s):  
L. Larrea ◽  
A. Abad ◽  
J. Gayarre
Keyword(s):  
Dissolved Oxygen ◽  
Activated Sludge ◽  
Nitrogen Removal ◽  
Suspended Solids ◽  
Complete Removal ◽  
Cod Removal ◽  
Nitrification Rate ◽  
Removal Rates ◽  
N Removal ◽  
Activated Sludge Processes

The effect on NH4-N removal rates in nitrification biofilters of filtered biodegradable COD and particulate COD leaving predenitrification biofilters was studied in a lab scale plant configured with the separated system of biofilters for secondary nitrogen removal from urban wastewaters. Applying a typical COD load of 11 kg/m3.day to the predenitrification biofilter and maximizing its COD removal by adding nitrates or by operating an improved control of the internal recycle, only 60% removal of filtered biodegradable COD was found. This value corresponds to the complete removal of the readily biodegradable substrate (30% of influent filtered COD) and 36% of filtered slowly biodegradable substrate (50% of influent COD). The remaining 64% of the latter entered the nitrification biofilter, causing competition between heterotrophs and nitrifiers for dissolved oxygen in the inner layers of the biofilm. Consequently the nitrification rate had relatively low values (0.5 kgN/m3.d) at 14°C despite using dissolved oxygen levels of 6 mg/l. This behaviour may explain the lower nitrification rates obtained in some cases of nitrification biofilters compared to those in tertiary nitrification after activated sludge processes. The particulate COD entering the nitrification biofilter is associated with the suspended solids leaving the denitrification biofilter which are adsorbed by the external layers of the biofilm, increasing its thickness. The activity of the nitrifiers was affected because of a lack of oxygen when the thickness was left to grow considerably. Therefore no significant particulate COD effect is expected to occur as long as backwashing is carried out with the appropriate frequency.

l1-norm optimal control of N-removal in an activated sludge process

1999 ◽  
Vol 7 (1) ◽  
pp. 63-70 ◽  
Author(s):  
L.J.S. Lukasse ◽  
K.J. Keesman ◽  
G. van Straten
Keyword(s):  
Optimal Control ◽  
Activated Sludge ◽  
Activated Sludge Process ◽  
L1 Norm ◽  
N Removal

Optimal design activated sludge process by means of multi-objective optimization: case study in Benchmark Simulation Model 1 (BSM1)

2014 ◽  
Vol 69 (10) ◽  
pp. 2052-2058 ◽  
Author(s):  
Wenliang Chen ◽  
Chonghua Yao ◽  
Xiwu Lu
Keyword(s):  
Optimal Design ◽  
Activated Sludge ◽  
Simulation Model ◽  
Process Parameters ◽  
Activated Sludge Process ◽  
Multi Objective Optimization ◽  
Cost Index ◽  
Multi Objective ◽  
Performance Indexes ◽  
N Removal

Optimal design of activated sludge process (ASP) using multi-objective optimization was studied, and a benchmark process in Benchmark Simulation Model 1 (BSM1) was taken as a target process. The objectives of the study were to achieve four indexes of percentage of effluent violation (PEV), overall cost index (OCI), total volume and total suspended solids, making up four cases for comparative analysis. Models were solved by the non-dominated sorting genetic algorithm in MATLAB. Results show that: ineffective solutions can be rejected by adding constraints, and newly added objectives can affect the relationship between the existing objectives; taking Pareto solutions as process parameters, the performance indexes of PEV and OCI can be improved more than with the default process parameters of BSM1, especially for N removal and resistance against dynamic NH4+-N in influent. The results indicate that multi-objective optimization is a useful method for optimal design ASP.

Effect of Diatomite Additive on Biomass Respiratory Activity in Activated Sludge

2011 ◽  
Vol 347-353 ◽  
pp. 264-268
Author(s):  
Wen Qi Zhang ◽  
Pin Hua Rao
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Coal Gasification ◽  
Respiratory Activity ◽  
Pilot Scale ◽  
Activated Sludge Process ◽  
Total Phenols ◽  
Biomass Activity ◽  
Coal Gasification Wastewater ◽  
The Stability

Laboratory and pilot scale experiments indicated that the diatomite additive could improve the stability of activated sludge process and the efficiency of COD removal for coal gasification wastewater treatment. In this paper, the effect of diatomite additive on biomass respiratory activity was studied to investigate the enhancing mechanism. Experimental results showed that diatomite additive could enhance biomass activity obviously when the biomass activity was inhibited by the wastewater with total phenols concentration of 188.9 mg/L -501.2 mg/L. It could be concluded that the mechanism of diatomite enhancing biomass activity were its adsorption of phenols and concentration of DO.

scholarly journals Predictive control of an activated sludge process for long term operation

2016 ◽  
Vol 304 ◽  
pp. 1031-1044 ◽  
Author(s):  
Chiara Foscoliano ◽  
Stefania Del Vigo ◽  
Michela Mulas ◽  
Stefania Tronci
Keyword(s):  
Activated Sludge ◽  
Predictive Control ◽  
Activated Sludge Process ◽  
Term Operation

Removal of nitrogen from coal gasification and coke plant wastewaters in A/O submerged biofilm-activated sludge (SBF-AS) hybrid system

1996 ◽  
Vol 34 (10) ◽  
pp. 17-24 ◽  
Author(s):  
Liu Junxin ◽  
Wang Baozhen ◽  
Li Weiguang ◽  
Jin Chengji ◽  
Cao Xiangdong ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Hybrid System ◽  
Coal Gasification ◽  
Coke Plant ◽  
Ammonia Nitrogen ◽  
Nitrifying Bacteria ◽  
Loading Rates ◽  
N Removal ◽  
Oxic Zone ◽  
Aerobic Reactor

Experimental research involving both laboratory and full-scale studies has been carried out to evaluate the nitrification-denitrification process carried out in a submerged biofilm (in anoxic zone)-activated sludge (in oxic zone) (SBF-AS) hybrid system for nitrogen removal from coal gasification and coke plant wastewaters. The anoxic reactor in the system was packed with fibrous carriers fixed on plastic plates of circular form for the attached growth of submerged biofilm with facultative denitrifying bacteria as dominant species to carry out denitrification, and the activated sludge process was used in the aerobic reactor for nitrification. As the denitrifying and nitrifying bacteria live under anoxic and aerobic conditions respectively in the hybrid system, the process was tested under the conditions of high organic and ammonia loading rates and short hydraulic retention time(HRT). The experimental results show that ammonia nitrogen, NH3-N removal is between 94% and 99.9% and COD removal between 80% and 95%.

Inhibitory effect of high calcium concentration on municipal solid waste leachate treatment by the activated sludge process

2017 ◽  
Vol 35 (5) ◽  
pp. 508-514 ◽  
Author(s):  
Yi Xia ◽  
Pin Jing He ◽  
Hong Xia Pu ◽  
Fan Lü ◽  
Li Ming Shao ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Removal Rate ◽  
Inhibitory Effect ◽  
Ammonia Nitrogen ◽  
Control Treatment ◽  
Activated Sludge Process ◽  
Leachate Treatment ◽  
N Removal ◽  
High Calcium ◽  
High Calcium Concentration

This research focused on the inhibitory effects of Ca on the aerobic biological treatment of landfill leachate containing extremely high Ca concentrations. When the Ca concentration in leachate to be treated was more than 4500 mg l−1, the total organic carbon removal rate was significantly reduced and the processing time to achieve the same removal efficiency was 1.4 times that in the control treatment without added Ca. In contrast, the total nitrogen and ammonia nitrogen (NH4+–N) removal efficiencies were positively related to the Ca concentration, increasing from 65.2% to 81.2% and from 69.2% to 83.7%, respectively, when the dosage of added Ca increased from zero to 8000 mg l−1. During aerobic treatment, the reductions of solution Ca concentration were in the range of 1003–2274 mg l−1 and were matched with increases in the Ca content in the residual sludge. The inhibition threshold of Ca in the leachate treated by the activated sludge process appeared to be 4500 mg l−1, which could be realized by controlling the influent Ca concentration and using an appropriate sludge return ratio in the activated sludge process.

Continuous village sewage treatment by vermifiltration and activated sludge process

2009 ◽  
Vol 60 (11) ◽  
pp. 3001-3010 ◽  
Author(s):  
Yin-Sheng Li ◽  
Yi-Qun Xiao ◽  
Jiang-Ping Qiu ◽  
Yi-Qi Dai ◽  
Paul Robin
Keyword(s):  
Activated Sludge ◽  
Sewage Treatment ◽  
Filter Material ◽  
Activated Sludge Process ◽  
Practical Application ◽  
Short Term ◽  
Organic Input ◽  
Term Operation ◽  
One Year

Rural sewage treatment is now paid more and more attention in China. Vermifiltration technology could be one of the practical options under the review of previous studies. It showed good removal rates of contaminants on small to pilot scales for short-term tests. However, the impacts of season, temperature or other unknown factors are usually not taken into account. In this study, a larger vermifilter was designed to treat the sewage on village scale for long-term operation. Filter material composition was optimized by a half year experimentation. The treatment effects of vermifiltration were also compared with traditional activated sludge process for the same influent sewage. The results showed that the designed vermifiltration system could continuously treat the sewage produced by more than 100 inhabitants per day. COD, BOD5 and SS concentration in outflow were rather stable despite the fluctuation of hydraulic loading rate and organic input during one year test. It can also remove N and P to some extent. A suspending design of vermifilter bed cause adequate oxygen content in outflow of vermifilter. The comparative test showed that the treatment efficacy of vermifiltration was similar as activated sludge process. Generally, this vermifiltration system has practical application value for village sewage treatment.

The Application of Fluidized Carrier in Reconstruction Project of Sewage Plant

2012 ◽  
Vol 518-523 ◽  
pp. 3212-3215
Author(s):  
Bing Wang ◽  
Guo Hui Feng ◽  
Ya Feng Li
Keyword(s):  
Activated Sludge ◽  
Cod Removal ◽  
Secondary Treatment ◽  
Activated Sludge Process ◽  
Effluent Quality ◽  
Design Standard ◽  
Sewage Plant ◽  
N Removal ◽  
Reconstruction Project

The traditional activated sludge process was transformed into A2O process with fluidized carriers. This technology was applied in reconstruction project of sewage plant. There was no need of altering civil construction. The effluent COD removal reached 95%. NH4+-N removal reached 92.2%. TN of effluent was less than 15 mg/L and TP was less than 1 mg/L. The process run stable and the effluent quality after secondary treatment could reach design standard.

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