Analysis of Degradation by Aerobic Recharge for Concentrated Leachate

2014 ◽  
Vol 675-677 ◽  
pp. 483-488
Author(s):  
Jian Zhang ◽  
Ping Xian ◽  
Long Hui Yang ◽  
Long Hui Zhan ◽  
Guang Hui Bu

Concentrated leachate obtained from landfill leachate by membrane separation was treated using technique of aerobic recharge. Variation of effluent COD, NH3-N and pH in concentrated leachate during aerobic recharge was studied. The impact of hydraulic loading on the removal rate of COD and NH3-N was investigated. The results indicate that, after passing through the three stages of rapid declining, smooth declining and stabilization, the variation of effluent COD of the concentrated leachate versus time maintains in the range of 900~2000 mg/L, and the corresponding removal rate is 88%~92%. The variation of effluent NH3-N versus time indicates a trend that it climbs up initially and then declines. The effluent NH3-N starts from 700 mg/L. After 35 days, it declines down to 18 mg/L and maintains in the range of 93%~99% with a corresponding removal rate up to 98%. Aerobic recharge reduces the build up of organic acids in the early stage. After 10 days, the pH value of the leachate maintains in the range between 7.5 and 9.0. The COD removal rate decreases from 94.39% down to 75.75% when the hydraulic loading increases from 12.5 mL / (L·d) to 75mL / (L·d), indicating a strong trend. In the mean time, the NH3-N removal rate decreases from 98.14% down to 90.11%, indicating a weak tread.

2014 ◽  
Vol 1073-1076 ◽  
pp. 941-948
Author(s):  
Li Li Wang ◽  
Qian Yang

The research in this paper focuses on improving the COD removal rate of the coking wastewater and the NH3-N removal rate and thus diversifying measures to dispose microbial floras in wastewater from the coal chemical industry. The means of adding nutrients, acid treatment and coagulation sedimentation react synergistically to dispose the organic contaminants in the coking wastewater. We attempted to combine Saccharomyces cerevisiae, Torula yeast, tropical Candida mycoderma, etc. to exploit the respective advantages to the full and improve the disposal effect. According to the COD sample (27000-30000) and NH3-N (2500-3000) offered by the client company, the COD removal rate ranged from 24.2% to 31.8% in the mixed experiment group of Saccharomyces cerevisiae and Torula yeast, with NH3-N removal rate from 63.5% to 69.6%. Obviously, the NH3-N removal rate produced good effect. Meanwhile, the COD removal rate ranged form 35.3% to 41.8% in the experiment group only adjusting PH value and the NH3-N removal rate ranged from 40.2% to 50.2%. It is obvious that NH3-N removal rate is influenced by the amount of bacterial strain.


1998 ◽  
Vol 38 (8-9) ◽  
pp. 213-221 ◽  
Author(s):  
Mohamed F. Hamoda ◽  
Ibrahim A. Al-Ghusain

Performance data from a pilot-plant employing the four-stage aerated submerged fixed film (ASFF) process treating domestic wastewater were analyzed to examine the organic removal rates. The process has shown high BOD removal efficiencies (> 90%) over a wide range of hydraulic loading rates (0.04 to 0.68 m3/m2·d). It could also cope with high hydraulic and organic loadings with minimal loss in efficiency due to the large amount of immobilized biomass attained. The organic (BOD and COD) removal rate was influenced by the hydraulic loadings applied, but organic removal rates of up to 104 kg BOD/ m2·d were obtained at a hydraulic loading rate of 0.68 m3/m2·d. A Semi-empirical model for the bio-oxidation of organics in the ASFF process has been formulated and rate constants were calculated based on statistical analysis of pilot-plant data. The relationships obtained are very useful for analyzing the design and performance of the ASFF process and a variety of attached growth processes.


2014 ◽  
Vol 1044-1045 ◽  
pp. 215-218
Author(s):  
Xian Huan Qiu ◽  
Hai Yu ◽  
Peng Fei Deng

In the presence of acetic acid, the effects of pH, processing time, addition of Fe2+ and H2O2 on dye wastewater treatment were studied. Experimental results showed that in the presence of acetic acid, when the pH value was 4, the processing time was 30.0min, addition of ferrous sulfate was 4.8g/L, and addition of hydrogen peroxide was 56mL/L, the treatment effect was the best, COD removal rate reached 51.0%. Further studied of the effect of the presence of acetic acid on Fenton’s oxidation of dye wastewater, the results showed that without of acetic acid, the COD removal rate was higher than that with acetic acid. And the effect of Fenton's reagent on oxidation of dye substances was interfered by the presence of acetic acid.


1997 ◽  
Vol 36 (2-3) ◽  
pp. 263-270 ◽  
Author(s):  
Cheng-Nan Chang ◽  
Jih-Gaw Lin ◽  
Allen C. Chao ◽  
Bo-Chuan Cho ◽  
Ruey-Fang Yu

Acrylonitrile and styrene are used as the raw materials for manufacturing acrylic fiber, thus they are often found as pollutants in the petrochemical wastewater. This study utilizes ozone to decompose the organic nitrogen contained in acrylonitrile and styrene, and the oxidation process was monitored using on-line measurements of oxidation-reduction potential (ORP) and pH. The efficiency of organic nitrogen decomposition was also estimated based on the COD, organic nitrogen, TOC, ammonia-N, nitrite, and nitrate measurements. Both the initial pH and alkalinity are observed to affect the degradation rate of organic nitrogen. The acrylonitrile sample with the lowest initial pH value (i.e., 4.0) has a shorter t1/2 of 18.9 min and that for samples of the highest initial pH (i.e., 11) was 34 min. The alkalinity of one acrylonitrile sample was boosted by adding 500 mg/l CaCO3, to simulate the field ABS (Acrylonitrile-Butadiene-Styrene) wastewater effluent. It was observed that within a short ozone contact time, the acrylonitrile sample spiked with 500 mg/l CaCO3 had the highest COD decomposition rate of 0.411 min−1, or 1.3 times more than that for samples without addition of CaCO3. Results of the ozonation process can be fitted with a modified Nernst equation for the various pH conditions. Additionally, the ozone treated synthetic ABS sample shows a faster COD removal rate in the subsequent biological process than those samples without ozone treatment.


2011 ◽  
Vol 255-260 ◽  
pp. 2797-2801
Author(s):  
Chen Yao ◽  
Chun Juan Gan ◽  
Jian Zhou

Effect of environment factors such as initial pH value, dissolved oxygen (DO) and temperature on phosphorus removal efficiency of phosphate reduction system was discussed in treating pickled mustard tube wastewater. Results indicate that environment factors have significant influence on dephosphorization efficiency. And, the impact of DO on phosphate reduction is mainly by affecting the distribution of micro-environment inner biofilm, manifest as phosphate removal rate decreased with a fall in DO concentration, while overhigh DO can lead to detachment of biofilm, thus causing the increase of effluent COD concentration, and so DO need to be controlled in the range of 6 mg/L. Moreover, a higher temperature is more beneficial to phosphorus removal by PRB. Unfortunately, exorbitant temperature can result in mass rearing of Leuconostoc characterized with poor flocculability in reactor, and that cause turbidity in effluent appeared as a rise in COD of effluent. Hence, the optimal temperature is found to be about 30°C.


2014 ◽  
Vol 644-650 ◽  
pp. 5419-5422
Author(s):  
Jin Xiang Fu ◽  
Hong Mei Li ◽  
Peng Fei Yu ◽  
Kai Zhao

This research adopts the important iron electrolysis, removal of the wastewater of high COD, SS, phosphorus pretreatment experiment. Discusses the different iron dosing quantity, iron carbon ratio, and pH value, reaction time on the COD and turbidity, the influence of the phosphorus removal effect. Studies show that iron important electrochemical test in brewery wastewater treatment static optimal processing conditions for: water pH value is 4, 5% dosage of iron filings, 60 min temperature response, COD removal rate was 52.31%. When the iron carbon ratio of 2:1, removing effect is good, can reach 54.53%.


2014 ◽  
Vol 69 (9) ◽  
pp. 1926-1931 ◽  
Author(s):  
F. Hassard ◽  
E. Cartmell ◽  
J. Biddle ◽  
T. Stephenson

The impact of organic loading rate (OLR) on carbonaceous materials and ammonia removal was assessed in bench scale rotating media biofilm reactors treating real wastewater. Media composition influences biofilm structure and therefore performance. Here, plastic mesh, reticulated coarse foam and fine foam media were operated concurrently at OLRs of 15, 35 and 60 g sCOD m−2d−1 in three bench scale shaft mounted advanced reactor technology (SMART) reactors. The sCOD removal rate increased with loading from 6 to 25 g sCOD m−2d−1 (P < 0.001). At 35 g BOD5m−2d−1, more than double the arbitrary OLR limit of normal nitrifying conditions (15 g BOD5m−2d−1); the removal efficiency of NH4-N was 82 ± 5, 27 ± 19 and 39 ± 8% for the mesh, coarse foam and fine foam media, respectively. Increasing the OLR to 35 gm−2d−1 decreased NH4-N removal efficiency to 38 ± 6, 21 ± 4 and 21 ± 6%, respectively. The mesh media achieved the highest stable NH4+-N removal rate of 6.5 ± 1.6 gm−2d−1 at a sCOD loading of 35 g sCOD m−2d−1. Viable bacterial numbers decreased with increasing OLR from 2 × 1010–4 × 109 cells per ml of biofilm from the low to high loading, suggesting an accumulation of inert non-viable biomass with higher OLR. Increasing the OLR in permeable media is of practical benefit for high rate carbonaceous materials and ammonia removal in the pretreatment of wastewater.


2001 ◽  
Vol 43 (11) ◽  
pp. 51-58 ◽  
Author(s):  
P. C. Male ◽  
W. A. Pretoruis

Wastewater high in phenolic content (948 mg/l) and dissolved solids (5.4 g/l) had to be treated to remove most of the organic material and toxic compounds. A laboratory scale High Pressure (3 bar) Bioreactor (HPB) was developed and operated to treat the wastewater using a ceramic ultra filtration membrane as biomass separator. The performance of the system was compared to a normal activated sludge plant (ASP) using sludge settling for separation. The HPB was more stable than the ASP, which twice became unstable with a resulting biomass loss. Both reactors removed 90% of the chemical oxygen demand (COD) loading, reducing the phenol concentration below 20 mg/l. The maximum COD removal rate of the HPB was 28 kg/m3.d compared to 15 kg/m3.d of the ASP, while the HPB achieved 16-32 times better oxygen transfer than the ASP. It was concluded that the HPB was the preferred treatment system compared to the ASP, when treating high strength inhibitory wastewaters, due to its stable operating performance and high COD removal rate.


2011 ◽  
Vol 356-360 ◽  
pp. 291-297 ◽  
Author(s):  
Jun Wen Li ◽  
Xin Li ◽  
Xiao Hui Xu ◽  
Dong Bing Wang

In the experiment that the disposal of low temperature and low turbidity water, we observed the influence of some factors ,such as the acting time of ultrasound, ultrasonic power, amount of coagulant and the PH value of system, in disposing the organic matters of low temperature and low turbidity water. The experimental results show that the water samples which were disposed by ultrasound acting firstly and then by coagulation precipitate processing are best. When ultrasonic acting is 9 min, ultrasonic power transferred to 25 W, the amount of coagulant polyferric sulphate is 12 mg/L and the system pH is 7, the maximum of COD removal rate will up to 87.2%.


2011 ◽  
Vol 396-398 ◽  
pp. 1918-1922 ◽  
Author(s):  
Li Ping Wan ◽  
Ying Feng Meng ◽  
Gao Li ◽  
Hua Zhou

Due to great variety additives and disposal difficulty, chemical method, biochemical method and solidification are adopted to treat fracturing wastewater in oil field. These processes easily bring about shortcomings, including high cost and secondary pollution. Studied on the treatment of fracturing wastewater of 4# well in Sichuan Oilfield by modified bentonite loading TiO2-Ag2O composite catalyst, COD removal rate is determined for different condition of pH value of solution, adding content of TiO2, inflating volume and light application time. The optimal condition is obtained as follows: pH value of solution is 3, adding content of TiO2 is 0.4-0.5%, inflating volume is 15L/min and light application time is 3h. Under this condition, COD removal rate of fracturing wastewater is 58.1%. The composite catalyst performance is stable and without secondary pollution. It is reusable by high temperature activation, so it can reduce wastewater treatment cost, and should be widely applied.


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