Average Removal Rates Of COD Research Articles

A Research on the Efficiency of Hydrolysis-AICS in Sewage Treatment Plant in North-Cities

The general existing low temperature problem in winter of north-city sewage treatment plant in the process of waste water treatment seriously affect the efficiency of the work. The research objective of this paper is to conduct investigate in the application of AICS method in Jilin Province, a sewage treatment plant engineering example has been employed to monitor the effluent of the indicators of sewage treatment under the low temperature condition during the winter the winter low temperature under the condition of sewage treatment plant effluent of the indicators; to understand the operation situation of sewage treatment plant, and to study the efficiency of hydrolysis - AICS processing waste-water. The result shows that: hydrolysis - AICS process works well in low temperature condition, the per TN removal rate is 76.79%, average removal rate of NH3 - N is 85.76%, average TP removal rate was 93.4%, the average COD removal rate was 90.6%. The effluent meet the national level A discharge standard requirements of "urban sewage treatment plant pollutant discharge standard". And through the retrenchment of the second pond and other ancillary equipment, Hydrolysis-AICS process could efficiently reduce the costs. Besides, the advantages of Hydrolysis-AICS process also include occupying small area, and operating easily and simply. Therefore Hydrolysis-AICS process is very helpful to achieve the sewage discharging standard in the northern towns.

Pilot Scale Study on Advanced Treatment of Coking Wastewater with Biological Activated Carbon Technology

This paper reports about a pilot-scale feasibility study of Advanced Treatment of Coking Wastewater with Biological Activated Carbon technology based on the better experimental data of laboratory scale test .The self-designed of the Biological Activated Carbon Aerated tower was based on the optimal operating conditions of the results obtained from laboratory scale test.The removal efficiency to pollutants of efficient compound bacterium is estimated in biological activated carbon process through the variation of COD concentration, chromaticity, and Contrast the total ion chromatogram and UV absorbance spectrum of effluent and inflow.The results of the pilot-scale test show that BAC technology may be a suitable option for the advanced treatment of Coking Wastewater. the efficient degrading strains can reproduce on the activated carbon quickly.Concentrations of COD and chromaticity in outflow water were at a lower level (with COD about 60mg/L and chromaticity about 50 degree), the average COD removal rate greater than 50% and chromaticity removal rate greater than 70%.

Performance evaluation of enhanced SBR in simultaneous removal of nitrogen and phosphorous.

BackgroundSimultaneous nitrogen, phosphorous and COD removal in a pilot-scale enhanced Sequencing Batch Reactor (eSBR) was investigated.MethodsThe reactor consisted of a pre-anoxic zone and internal recycle and was fed with synthetic wastewater. The study was performed by operating the reactor in 6-hour cycles in three different operational modes during a time frame of 279 days.ResultsUnder the best operational conditions, the average removal rate of COD, TN, and TP were obtained as 93.52, 88.31, and 97.56%, respectively.ConclusionsA significant denitrifying phosphorus removal (more than 80%) occurred at run1 and 3 which started the cycle under anoxic condition.

An Engineering Practice of Industrial Wastewater Treatment with Fe/Cu Bimetallic Process

Fe/Cu bimetallic process was developed as a new industrial wastewater pretreatment method. It was difficult for an industrial park wastewater treatment plant in Shanghai to treat the wastewater with many refractory pollutants and match the improved discharge standards. The plant needed renovation and adopted Fe/Cu process as a core pretreatment technology. 60,000 tons of wastewater is treated in the plant every day and the average removal rate of COD, BOD, total phosphorous (TP) and color was 73%, 77%, 55% and 48% respectively before renovation. After renovation, the average removal rate of COD, BOD, total phosphorous (TP) and color was reached to 86%, 93%, 76% and 85%, respectively. The engineering practice shows that the removal rate of COD, color and TP in Fe/Cu tank reached 29.7%, 60% and 53.6%. The continuous operating data in two years shows that Fe/Cu process can effectively improve the biodegradability of wastewater and enhanced the subsequent biological treatment. The successful engineering practice indicts that the slag dropping quickly effectively avoid agglomeration and clogging of the Fe/Cu filler and the operating cost is very low.

Study on Biological Purification Effect on Tail Water from Sewage Treatment Plant at Small-Scaled Town, South Jiangsu

As a cost-effective technology, using biological treatment technology to treat tail water has been gradually promoted in and abroad. Biological treatment technology uses the organic combination of water ecosystem to remove the organic pollutants and pollutants such as N and P which cause water eutrophication. This paper takes Jiangyin City Xinqiao Town Sewage Treatment Plant as example to construct bio-ecological combined constructed wetlands system near natural river course to treat tail water from sewage treatment plant and investigates the removal efficiency of combination process for COD, ammonia, TN and TP in tail water. The research indicates that bio-ecological combined constructed wetlands system has good removal efficiency for pollutants in tail water. And the average removal rate of COD, ammonia, TN and TP are 29%, 31%, 18%, and 8%; the average effluent concentration of them are 35.54mg/L, 0.97mg/L, 10.77 mg/L, and 0.11 mg/L. The result exactly matches the first grade A standard of Urban Sewage Treatment Plant Pollutant Discharge Standard (GB18918-2002). It has great potential for tail water treatment and is suitable for rural regions. The research result provides both the data and theoretical basis for improvement of biological treatment technology of tail water from sewage treatment plant, and also provides direct theoretical basis and practical experience for promotion and research of wetlands ecosystem.

Study on the Impact of DO and Organic Matter on Aerobic Granular Sludge Treating Municipal Sewage

The experiment uses municipal sewage as the research object and runs SBR reactor in completely aerobic conditions. Through controlling different of DO concentration and COD concentration, we study spreading comparison. The results show that when DO concentration was 1mg/L, the removal effect of aerobic granular sludge process in SBR treating municipal sewage was best, the average removal rate of COD, ammonia nitrogen, total nitrogen and phosphorous was 90.12%,98.95%,87.65% and 83.74% respectively. When COD concentration of influent was about 400mg/L, the treatment effects of aerobic granular sludge for COD, ammonia nitrogen, total nitrogen and phosphorous were all better, the average removal rate was up to 92.33%,98.83%,88.17% and 80.25% respectively.

An Experimental Study on Compatible Solute Ectoine Dosing of High Salinity Wastewater

When the reactor is added with ectoine of concentrations of 0, 0.1, 1 and 10 mmol/L, the impacts on brine waste treatment efficiency are investigated. The results show that the outflow COD and ammonia nitrogen removal rates are the highest, when the ectoine concentration is 0.1 mmol/L. The brine waste treatment efficiency under addition of ectoine of 1 and 10 mmol/L is even worse than that without ectoine addition. It can be preliminarily determined that the best ectoine dosage is in between 0.1-1.0 mmol/L. When ectoine concentrations added in reactors are 0.2, 0.5, 0.8 and 1.0 mmol/L, the results show that the average reactor outflow COD and ammonia nitrogen removal rates are increased compared with those of reactor without adding ectoine. But when ectoine of 1.0 mmol/L is added, the outflow COD and ammonia nitrogen removal rates decrease. When ectoine dosage is 0.5 mmol/L, the reactor outflow COD and ammonia nitrogen values are the lowest, the removal rates are the highest, the average COD removal rate is 74.46%, and the average ammonium nitrogen removal rate is 54.97%. Compared with reactor without adding ectoine, COD and ammonium nitrogen removal rates are increased by 13.16% and 26.81%. Therefore, the best dosage of ectoine is 0.5 mmol/L.

Research on treatment of printing and dyeing wastewater by hybrid anaerobic baffled reactor

The printing and dyeing wastewater was treated by a pilot-scale hybrid anaerobic baffled reactor (HABR) which was modified from general anaerobic baffled reactor by adding combined packing in the upper part of each compartment and inert carrier at the bottom of the reactor. The start-up of the reactor, the performance of HABR in treating printing and dyeing wastewater, and the transformation of sulfate and removal of bivalent sulfur in the treatment were investigated. The results showed that less time was taken during the start-up in comparison with the general one, and higher COD removal efficiency and sufficient color removal rate were also obtained in the HABR. When the hydraulic retention time was 12–13 h and the sludge return ratio was 0.3, the average COD and color removal rates were 47% and 56%, respectively. The anaerobic bacteria community in each compartment developed well because of available substrates and specific environmental conditions. The results also showed that high reduction rate of SO42- was reached in the HABR, and the S2− transformed from SO42- could be removed by adding Fe2+ into the wastewater in order to reduce the inhibitory effect on the anaerobic bacteria and the odor.

Effect of C/N ratio and aeration rate on performance of internal cycle MBR with synthetic wastewater

Effect of C/N ratio and aeration rate on performance of continuously operated internal circulation membrane bioreactor (ICMBR) was investigated thoroughly using synthetic domestic wastewater. The results show that COD and total nitrogen (TN) removal efficiencies were improved with the increase of C/N ratio under certain conditions (T = 25 °C, MLSS = 10 g/L, aeration rate was 0.15 m3/h, influent NH3-N concentration was 20 mg/L, influent NO3--N concentration was 100 mg/L, and HRT = 12 h). Meanwhile, a steady ammonia nitrogen (AN) removal rate (~80%) was obtained when C/N ratio increased from 2:1 to 6:1. Furthermore, when C/N ratio was 6:1 and aeration rate was 0.15 m3/h, average removal rates of COD, AN, and TN reached 98.5, 97.4, and 52.6%, respectively. Additionally, the improvement in activity of denitrifying bacteria could increase TN removal rate at a lower aeration rate. Under the optimal operation parameters (C/N ratio of 6:1 and aeration rate of 0.05 m3/h), the high average removal efficiencies of COD (96.0%), AN (96.4%), and TN (81.0%) were obtained by ICMBR. Finally, the membrane fouling was unobvious during this experiment process.

Polluted River Water Treatment Using Multi-Soil-Layering System (MSL) in Different Surface Loads

For a better application of multi-soil-layering (MSL) system to treat polluted river water flowing into Dianchi Lake in different surface loads, six systems are set on the river bank of New Yunliang River for a four-month-experiment. The surface loads are set as 800L/m2•d, 1000 L/m2•d, 1500 L/m2•d, 2000 L/m2•d, 3000 L/m2•d and 4000 L/m2•d, respectively. When the surface load is 1000L/m2•d, the average removal rate of COD, TN, NH4+-N and TP are 74.8%, 28.9%, 88.5% and 87.0% respectively; when the surface load is 1500 L/m2•d, the average removing rate of COD, TN, NH4+-N and TP are 72.4%, 20.2%, 83.9% and 84.1% respectively. The surface load has a big influence on the removal of COD, NH4+-N and TP. Due to insufficient denitrification, the removing rate of TN is comparatively low. With a view to the removing effect and load reduction and the long-term operation conditions of the system, the most appropriate surface load is between 1000~1500 L/m2•d.

The Application of A/O Treating Mixing Pharmaceutical Wastewater

A/O was applied to treat the mixing pharmaceutical wastewater. After 1.5 months, SV could reach 20%~27% stably, the sludge biofloccus shows filemot and a good precipitation performance. The removal rate of COD can basically reach 70%, the removal rate of NH3-N could increase into 60%, the A/O system started successfully. When A/O system run stably, the average removal rate of COD and NH3-N could reach 75% and 55%, respectively.

Enhanced performance of bio-cathode microbial fuel cells with the applying of transient-state operation modes

To enhance the MFC's denitrification performance, this study investigated three different external circuits/operation modes of the MFC: alternative charging and discharging (ACD), intermittent charging (IC) and constant external resistance (R). Results showed that the ACD and IC modes offered larger output currents as well as higher nitrate and COD removal rates than the steady R mode. The best performance was achieved with the ACD mode. At the initial [COD]=~1200 mg/L and [NO3(-)]=~140 mg/L, the ACD mode delivered an average power density of 0.91 W/m(3), an average nitrate removal rate of 15.5mg/(Ld) and an average COD removal rate of 137 mg/(Ld), 268%, 207% and 168% respectively greater than those by the R mode. The enhancement by the ACD and IC modes was more pronounced at lower nitrate and COD concentrations and/or with the lack of stirring of electrolyte solutions.

Pengaruh Kecepatan Aliran Terhadap Kandungan COD Pada Pengolahan Air Limbah Kecap Secara Aerobic/Aaerobic

Removal rate of COD varies with COD volume loading, aeration time and or flow rate of incoming waste water. Anaerobic process showed that the higher flow rate was continued the lower COD removal was yielded, whereas the aerobic pointed out that COD removal was obtained higher and higher as the flow rate was increased. Although coagulant was not used for this treatment, the experiment appeared to indicate a good result where average COD removal rate for Q1• Qz. Qjand Q4 are 93.8, 93.2, 91.0, and 92.4 % respectively.

Study on Spray on Degradation of TNT-RDX Explosives Wastewater by Synergetic Ozonation

TNT-RDX wastewater is hard to biodegrade and highly toxic. The self-made reactor was used to degrade the wastewater, spray and the conditions of droplet diameter, number of nozzle, spray height were clearly observed. The results show that the average COD removal rate of TNT-RDX wastewater was 69.6%.The spray conditions can improve the dispersion of the wastewater and increase the use of the residual ozone in gas phase. Keywords: Spray; TNT-RDX wastewater; ozone; UV; GAC

Study on Rural Sanitary Sewage Treatment in Compound Purifying Tank

In the present work, a novel compound purifying tank was adopted in the rural sanitary sewage treatment. The cultivation and acclimation of biological film could be completed in a short start-up by aerobic precoating. According to the running results,the average COD removal rate reached 59.62%,and the removal efficiency of TP was 33.4%.For the denitrogenation,the removal rates were not remarkable (21.7 to NH4+-N,21.9 to TN),but the large removal quantity of NH4+-N and TN were abtained as 8.58mg/L and 9.12mg/L,respectively. The study suggests that the compound purifying tank is a potential alternative for rural sanitary sewage treatment.

Kinetic Analysis on Rotating Biological Contactor Treatment of Organic Matter

This paper adopts a 3-stage rotating biological contactor (RBC), studies kinetic analysis on RBC treatment of organic matter .Water temperature 25 °C and hydraulic retention time (HRT) 5h , COD concentration of influent varies from about 400 to 700mg / L, the average COD removal rate is 85% . According to Monod and Michaelis-Menten formula, organic matter removal kinetics equation in the first stage of RBC can be catched. When DO≥2mg/L, organic matter removal kinetic equation: U1=7.02S1/( S1+640.70), DO<2mg/L, organic matter removal kinetic equation: U2=35.97S2/( S2+4848.92) .Where U is substrate removal rate of unit area of disc, S is the organic matter concentration of substrate. Some reference values of the equation are very useful for practical application of RBC.

A Study on Advanced Treatment for Coking Wastewater with Biological Activated Carbon Based on Efficient Degrading Flora

The removal efficiency of degrading flora which has been constructed is investigated in biological carbon process through the variation of COD and chromaticity. The results show that the efficient degrading strains can reproduce on the activated carbon quickly；the biological activated carbon reactor，in which degrading flora to coking waste water are inoculated，is adopted to carry out the treatment of wastewater，in such a way the COD and chromaticity in outflow water can remain at a lower level (with COD about 50mg/L and chromaticity about 50 degree). The average COD removal rate is 71% and the chromaticity removal ratio is 95%.

Influence of C/N Ratio on SND and Microbiological Analysis in Catching Bed Biofilm Reactor Using Acrylic Resin Fiber as Carrier Materials in Civil Engineering

In this study, effect of C/N ratio on denitrification were investigated using four sets of parallel catching bed reactors, which were using acrylic resin fiber (ARF) as carrier materials. The results indicate that this process which was used in wastewater treatment of civil engineering can get better COD and nitrogen removing performance. NH4+-N removal rate reduced with the increasing of C/N ratio, and the average removal rate of COD and the total nitrogen (TN) increased when C/N ratio is increased. When C/N ratio exceeded 12, TN removal rate has no obvious growing. Meanwhile, fluorescent in situ hybridization (FISH) analysis indicated that the biomass in the biofilm were much richer than which in the suspension, and the ammonia oxidizing bacteria have a easy access to be dominant bacterial community in lower C/N ratio.

Experimental Study on the Treatment of Low Concentration Domestic Sewage in a Zeolite Biological Aerated Filter

The present paper describes the performance and the feasibility of the zeolite biological aerated filter applied to treat the low concentration sewage as recalaimed water reuse as cooling tower make-up water in the thermal power plant. The result showed that average removal rate of COD, turbidity and ammonia was 79%, 86% and 50% respectively, under the conditions of hydraulic loading L=4.4m3/m2•h, gas-water ratio=2:1, HRT=0.63h, t=8.5~14.5oC and backwashing in 48 hours. The average concentration of COD, turbidity and ammonia in effluent was 13.0mg/l, 4.2NTU and 1.95mg/l, respectively. The effluent quality met the water quality standards of the reuse of urban recycling water-water quality standard for industrial uses GB/T19923-2005.

The Study of Operation and Dynamic on the Modified A<sup>2</sup> / O Process

Based on recent experimental data in the Guangrao Wastewater Treatment Plant, the performance and dynamics of modified A2 / O process was summarized. The results shows that: the average removal rate of COD is 73.7%, and COD is mainly removed in pre-anoxic pool; the average removal rate of TN is 64.2%, and TN is mainly removed in pre-anoxic and aerobic pool; the average removal rate of TP is 79.48%, and phosphorus release happens in the pre-anoxic pool and phosphorus uptake happens in anoxic and aerobic pools. Based on the material balance and the results, the dynamic equation of degradation for pollutants in each stage is established, and the predicted and actual values are compared, the results show that the dynamic equations are fit for the Guangrao Wastewater Treatment Plant.