Biological treatment of high-pH and high-concentration black liquor of cotton pulp by an immediate aerobic-anaerobic-aerobic process

2009 ◽  
Vol 60 (12) ◽  
pp. 3275-3284 ◽  
Author(s):  
Miao Lihong ◽  
Li Furong ◽  
Wen Jinli
Keyword(s):  
Removal Rate ◽  
Black Liquor ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Laboratory Scale ◽  
The Novel ◽  
High Concentration ◽  
Treatment Unit ◽  
Alkaliphilic Bacteria ◽  
Aerobic Process

In this study, an immediate aerobic-anaerobic-aerobic (O/A/O) biological process was established for the treatment of black liquor of cotton pulp and was tested by both laboratory-scale batch experiment and pilot-scale continuous experiment. The effects of the hydraulic retention time (HRT) were studied, as were the alkaliphilic bacteria number, the culturing temperature and the concentration of black liquor on COD (chemical oxygen demand) removal. The total COD (CODtot) removal rate of the novel O/A/O process, for a black liquor with influent CODtot over 8,000 mg/L and pH above 12.8, was 68.7 ± 4% which is similar with that of the traditional acidic-anaerobic-aerobic process (64.9 ± 3%). The first aerobic stage based on alkaliphilic bacteria was the crucial part of the process, which was responsible for decreasing the influent pH from above 12 to an acceptable level for the following treatment unit. The average generation time of the alkaliphilic bacteria in the black liquor was about 36 minutes at 40°C in a batch aerobic activated sludge system. The efficiency of the first aerobic stage was affected greatly by the temperature. The CODtot removal at 55°C was much lower in comparison with the CODtot removal at 45°C or 50°C. Both the laboratory-scale batch experiments and the pilot-scale continuous experiment showed that the CODtot removal rate could reach about 65% for original black liquor with a pH of about 13.0 and a COD of 18,000–22,000 mg/L by the immediate O/A/O process. The first aerobic stage gave an average CODtot removal of 45.5% at 35°C (HRT = 72 h) at a volume loading rate of 3.4 kg COD m−3 d−1.

Hydrolysis of organic wastewater particles in laboratory scale and pilot scale biofilm reactors under anoxic and aerobic conditions

1998 ◽  
Vol 38 (8-9) ◽  
pp. 179-188 ◽  
Author(s):  
K. F. Janning ◽  
X. Le Tallec ◽  
P. Harremoës
Keyword(s):  
Organic Matter ◽  
Mass Balance ◽  
Particulate Organic Matter ◽  
Removal Rate ◽  
Pilot Scale ◽  
Laboratory Scale ◽  
Synthetic Wastewater ◽  
Aerobic Conditions ◽  
Biofilm Reactors ◽  
Hydrolysis Of

Hydrolysis and degradation of particulate organic matter has been isolated and investigated in laboratory scale and pilot scale biofilters. Wastewater was supplied to biofilm reactors in order to accumulate particulates from wastewater in the filter. When synthetic wastewater with no organic matter was supplied to the reactors, hydrolysis of the particulates was the only process occurring. Results from the laboratory scale experiments under aerobic conditions with pre-settled wastewater show that the initial removal rate is high: rV, O2 = 2.1 kg O2/(m3 d) though fast declining towards a much slower rate. A mass balance of carbon (TOC/TIC) shows that only 10% of the accumulated TOC was transformed to TIC during the 12 hour long experiment. The pilot scale hydrolysis experiment was performed in a new type of biofilm reactor - the B2A® biofilter that is characterised by a series of decreasing sized granular media (80-2.5 mm). When hydrolysis experiments were performed on the anoxic pilot biofilter with pre-screened wastewater particulates as carbon source, a rapid (rV, NO3=0.7 kg NO3-N/(m3 d)) and a slowler (rV, NO3 = 0.3 kg NO3-N/(m3 d)) removal rate were observed at an oxygen concentration of 3.5 mg O2/l. It was found that the pilot biofilter could retain significant amounts of particulate organic matter, reducing the porosity of the filter media of an average from 0.35 to 0.11. A mass balance of carbon shows that up to 40% of the total incoming TOC accumulates in the filter at high flow rates. Only up to 15% of the accumulated TOC was transformed to TIC during the 24 hour long experiment.

Municipal waste sludge digestion in an autothermal aerobic sequencing batch reactor

2008 ◽  
Vol 58 (6) ◽  
pp. 1237-1243
Author(s):  
Gregor D. Zupanèiè ◽  
Viktor Grilc ◽  
Milenko Roš ◽  
Nataša Uranjek-Ževart
Keyword(s):  
Batch Reactor ◽  
Oxygen Demand ◽  
Batch Process ◽  
Pilot Scale ◽  
Laboratory Scale ◽  
Pure Oxygen ◽  
Sludge Digestion ◽  
Scale Size ◽  
Aeration System ◽  
Maximum Temperatures

An autothermal aerobic sequencing batch process for sludge digestion and “class A” biosolids production was developed. The process was tested in laboratory and pilot scale size up to 150 PE, which can be considered a full scale size in some cases. In this process the maximum temperatures of 61.2°C and 60.2°C were achieved in laboratory scale in pilot scale equipment, respectively. The degradation efficiency of total chemical oxygen demand of sludge was between 50 and 70%. Similar results were achieved using pure oxygen in laboratory scale and oxygen/air mixture 1:1 by volume. The reactor scale greatly affects the achievement of thermophilic temperature. In smaller sizes the convective heat losses are the prevailing heat sink and the process is unable to produce enough heat to reach thermophilic temperature. Larger systems produce excess heat and can be installed with less intense aeration systems. The limit of air aeration system is at the size of about 500 PE.

Multistage treatment wetland for treatment of reject waters from digested sludge dewatering

2013 ◽  
Vol 68 (6) ◽  
pp. 1223-1232 ◽  
Author(s):  
M. Gajewska ◽  
H. Obarska-Pempkowiak
Keyword(s):  
High Efficiency ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Nitrogen Compounds ◽  
High Concentration ◽  
Treatment Wetland ◽  
Sludge Dewatering ◽  
Digested Sludge ◽  
Reed Beds ◽  
Colloidal Fraction

The paper presents the influence of sewage composition on treatment in pilot-scale facility for reject waters (RW) from sewage sludge centrifugation. The facility consisted of mechanical (two tanks with 10 d retention each) and biological parts composed of three subsurface flow reed beds working in batch. Two years of monitoring of the facility proved high efficiency removal of predominant pollutants: chemical oxygen demand (COD) 75–80%, biochemical oxygen demand (BOD) 82.2–95.5% and total nitrogen 78.7–93.9% for low ratio of BOD5/COD in discharged RW. The differences in efficiency removal were correlated with the composition of organics and nitrogen compounds rather than with concentrations. It was assumed that high concentration of colloidal fraction of Org-N and COD in discharged RW led to a decrease in efficiency removal.

Treatment of Refinery Wastewater with Isolated Biological Aerated Filters: A Pilot-Scale Study

2012 ◽  
Vol 610-613 ◽  
pp. 2332-2341
Author(s):  
Jian Guang Huang ◽  
Li Zhong ◽  
Wen Yu Xie
Keyword(s):  
Waste Water ◽  
Waste Water Treatment ◽  
Oxygen Demand ◽  
Volume Ratio ◽  
Pilot Scale ◽  
Mean Value ◽  
Operating Conditions ◽  
Water Volume ◽  
High Concentration ◽  
Set Up

A pilot scale biochemical treatment system containing three isolated biological aerated filters, one oil-separation pool and one secondary sedimentation tank was set up and used for high concentration organic waste water treatment. Effect of different operating conditions on Chemical Oxygen Demand (CODCr), sulphides, hydroxybenzene and oil degradation was investigated. And the ways of sulphides removal were also explored. While CODCr, the concentrations of sulphides, hydroxybenzene and oil in the waste water are no more than 1500 mg/L, 800 mg/L, 15 mg/L and 150mg/L, respectively, the system can run stably and the total removal of these pollutants is 88.8%, 98.8%, 96.8% and 91.0% accordingly though hydraulic retention time (HRT) varies from 7.95 hr to 15.90 hr and the air/water volume ratio (AWVR) varies from 12 to 8. Most of the sulphides are removed by Biodegradation with Isolated Biological Aerated Filters. Most of the pollutants are removed in the 1st BAF and about 96.5% by mean value of sulphides transforme into elemental sulfur and only about 2.7% by mean value of sulphides transforme into sulphates.

scholarly journals Polishing of Chemical Oxygen Demand (COD) Using Moving Bed Bio-Reactor

2015 ◽  
Vol 773-774 ◽  
pp. 1281-1285
Author(s):  
Jamal Ali Kawan ◽  
Rakmi Abd-Rahman ◽  
Othman bin Jaafar ◽  
Fatihah Suja
Keyword(s):  
Chemical Oxygen Demand ◽  
Municipal Wastewater ◽  
Removal Rate ◽  
Research Work ◽  
Real Life ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Biofilm Reactor ◽  
Moving Bed ◽  
Building Engineering

The pilot-scale experiment in moving bed biofilm reactor (MBBR) with a capacity of 433 L was carried out for this study with real life situations, it was decided that the complete research work must be done under as realistic conditions as possible,i.e.with real municipal wastewater, chemical free and with local commercially available products such as carriers for biofilm reactor. The reactor was start-up in 30/9/2013 up to date, Effluent from clarifier of STP used as influence of MBBR for polishing. MBBR is using continues down flow to polish effluent municipal wastewater from a faculty of new building engineering community in UKM to get the water free from main pollutant parameters, for reuse in the irrigation or discharge to the river. Laboratory experiments will conduct with different hydraulic retention time (HRT), filling ratio of plastic (Enviro Multi Media) in the MBBR about 5%. Aerobic reactors used the majority of the decaying organic material. An average removal rate of 41.75%, 32.85%, 24.80% and 35.77% of initial chemical oxygen demand (COD) were achieved under a HRT of 24hr, 12hr, 6hr and 2hr, respectively. The model simulated results showed good agreements with experimental results. The model could be employed in the design of a full-scale MBBR process for simultaneous removal of organic carbon from effluent STP.

Comparison on Permanganate and Ozone as Pre-Oxidation Agents

2014 ◽  
Vol 955-959 ◽  
pp. 3408-3413 ◽  
Author(s):  
Hong Wei Sun
Keyword(s):  
Drinking Water ◽  
Treatment Process ◽  
Removal Rate ◽  
Oxygen Demand ◽  
Drinking Water Treatment ◽  
Pilot Scale ◽  
Turbidity Removal ◽  
Trihalomethane Formation Potential ◽  
Water Treatment Process ◽  
Oxidation Reactor

Comparative study on permanganate and ozone as pre-oxidation agents were performed on pilot scale with traditional drinking water treatment process, chemical oxygen demand (COD), total organic carbon (TOC), UV254, turbidity, trihalomethane formation potential (THMFP) were examined at each reactor’s effluent. The results show that at pre-oxidation reactor, the total organic remained stable after by the two agents, while for UV254, pre-ozonation has a removal rate of 34%, comparing that of 17% by permanganate. At the sedimentation process, 0.4 mg/L permanganate improves the removal rate of turbidity and COD by 0.99 % and 8.4%, respectively; while a positive COD removal of 11.8 % was achieved by 0.9 mg/L pre-ozonation, and an average of-10.08% turbidity removal was achieved at applied dosage (0.5, 0,9 and 1.5 mg/L), which can be made up for in the followed sand filtration reactor. Both permanganate and pre-ozonation show higher removal rate of THMFP for the finished water.

scholarly journals Assessment of the performance of intermittent planted filters in treating urban wastewater under arid climate

2021 ◽  
Author(s):  
Hiba Tlili ◽  
Mahmoud Bali ◽  
Rachid Boukchina
Keyword(s):  
Removal Rate ◽  
Energy Requirement ◽  
Low Cost ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Ammonium Nitrogen ◽  
Quality Parameters ◽  
Urban Wastewater ◽  
Hydraulic Load

Abstract Intermittent planted filters are extensive biological purification techniques aimed at oxidizing and decontaminating urban wastewater at a low cost and with minimum environmental impacts. The main purpose of this study was to evaluate the performances of intermittent planted filters in treating urban wastewater under arid conditions of southern Tunisia. The experimental study was carried out on a pilot scale plant comprising five constructed gravel-sand basins. Screened urban wastewater effluent was intermittently applied with a daily hydraulic load of 400 L/m2. Several water quality parameters were monitored at the inlet and outlet of this treatment plant. The average removal rate were 94.8%, 92.3%, 99.3%, 89.9% and 93.3% for chemical and biological oxygen demand, total suspended solids, ammonium nitrogen and orthophosphate, respectively. Additionally, results demonstrated that this treatment system is capable to remove 3.67, 3.22 and 2.44 log units of total and faecal coliforms, and faecal streptococci, respectively. Results showed that Phragmites australis allowed the development of biofilm in the sand filter beds, improving their purification efficiency. Furthermore, no bio-sludge production, no mechanical aeration, low energy requirement (0.02 kW/m2) and green aesthetic ambience are the additional particular strengths of the proposed pilot-plant.

Evaluation of phosphorus removal in anaerobic-anoxic-aerobic system - via polyhydroxyalkonoates measurements

1998 ◽  
Vol 38 (1) ◽  
pp. 107-114 ◽  
Author(s):  
S. H. Chuang ◽  
C. F. Ouyang ◽  
H. C. Yuang ◽  
S. J. You
Keyword(s):  
Uptake Rate ◽  
Phosphorus Removal ◽  
Loading Condition ◽  
Phosphorus Uptake ◽  
Pilot Scale ◽  
Phosphorus Release ◽  
Biological Phosphorus Removal ◽  
Organic Loading ◽  
High Concentration ◽  
Aerobic Process

Accumulating and utilizing PHAs (polyhydroxyalkanoates), i.e. a major carbon reserve of polyphosphate accumulating organisms (PAOs), is a prerequisite for phosphorus removal in an enhanced biological phosphorus removal (EBPR) system. To evaluate phosphorus removal, this study investigates the behavior of PHAs in a hybrid anaerobic-anoxic-aerobic process, operating under various sludge retention times (5, 10, 12 and 15 days) and dissolved oxygen conditions (0.5, 1.0 and 2.0 mg/l in aerobic stage). PHAs and phosphorus measurements in the pilot-scale experiments demonstrate that the PHAs content of sludge closely relates to phosphorus release and uptake behavios under anaerobic and aerobic conditions, respectively. The aerobic specific-phosphorus-uptake-rate is directly proportional to PHAs content of sludge in the anoxic stage. When the process is under a high organic loading condition, the sludge exhibits a large amount of PHAs having accumulated in the anoxic stage and a high phosphorus uptake rate in the subsequent aerobic stage. However, experimental results confirm that anoxic phosphorus release, leading to a high concentration of phosphorus flow into the aerobic stage, causes deficient phosphorus removal under a high organic loading condition. Moreover, a low PHAs content of sludge causes incomplete phosphorus removal; the phenomenon occurs when the process is under a low organic loading condition. Based on the results presented herein, we can conclude that the organic loading should be carefully controlled for phosphorus removal in the anaerobic-anoxic-aerobic process.

scholarly journals Degradation of high-concentration p-nitrophenol by Fenton oxidation

2020 ◽  
Vol 81 (10) ◽  
pp. 2260-2269
Author(s):  
Xiao Qing Lin ◽  
Wei Min Kong ◽  
Xiao Lin
Keyword(s):  
Degradation Rate ◽  
Removal Rate ◽  
Oxidative Degradation ◽  
Oxygen Demand ◽  
Fenton Oxidation ◽  
Utilization Efficiency ◽  
Molar Ratio ◽  
High Concentration ◽  
Initial Concentration ◽  
Toc Removal

Abstract This work aimed to degrade high-concentration p-nitrophenol (PNP) by Fenton oxidation. We studied various reaction parameters during Fenton oxidation, such as the iron dosage (as Fe2+), the initial concentration and temperature of PNP, and the dosage of hydrogen peroxide (H2O2), especially the influence of temperature on the PNP degradation rate and degree. Under the addition of the same molar ratio of H2O2/Fe2+ and H2O2 dosage according to the theoretical stoichiometry, the PNP degradation rate and the removal rate of total organic carbon (TOC) increased significantly with the increase in the initial PNP concentration. Moreover, the oxidative degradation effect was significantly affected by temperature. The increased reaction temperature not only significantly reduced the Fe2+ dosage, but also greatly promoted the removal rate of chemical oxygen demand (COD) and TOC, and improved the utilization efficiency of H2O2. For example, when the initial concentration of PNP was 4,000 mg·L−1, and the dosage of Fe2+ was 109 mg·L−1 (H2O2/Fe2+ = 200), the removal rates of COD and TOC at 85 °C reached 95% and 71% respectively. Both were higher than the 93% COD removal rate and 44% TOC removal rate when the dosage of Fe2+ was 1,092 mg·L−1 (H2O2/Fe2+ = 20) at room temperature.

COD and NH4-N Removal in Two-Stage Batch-Flow Constructed Wetland

2013 ◽  
Vol 448-453 ◽  
pp. 604-607 ◽  
Author(s):  
Hong Jie Sun ◽  
Xin Nan Deng ◽  
Rui Chen
Keyword(s):  
Constructed Wetland ◽  
Removal Rate ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Pilot Scale ◽  
Ammonia Nitrogen ◽  
Two Stage ◽  
Removal Rates ◽  
N Removal ◽  
Domestic Wastewater Treatment

Research was conducted on pilot-scale, two-stage batch-flow constructed wetland systems for domestic wastewater treatment. Synthetic domestic wastewater was treated in a pre-acidification reactor with a hydraulic retention time (HRT) of 3 hours and the average removal rate of chemical oxygen demand (COD) and ammonia-nitrogen (NH4-N) reached 30% and 13.6%, respectively. The first-stage constructed wetland operated with up-flow and batch feed and drain. One cycle was 12h, including 6h feed and 6h drain. With HRT of 3 days, the effluent COD concentrations fluctuated from 32.5 mg/L to 103.4 mg/L, removal rates varied from 60% to 88%; effluent NH4-N concentrations were in the range of 4.8 mg/L to 10.8 mg/L, removal rates varied from 50% to 70%. The second-stage constructed wetland operated with down-flow, which one cycle was 24h, including 12h feed and 12h drain. With HRT of 1 day, effluent COD concentrations varied from 15.7 mg/L to 48.7 mg/L, removal averaged 53.2%; effluent NH4-N concentrations ranged from 0 mg/L to 0.4 mg/L, average removal exceeded 99%. The spatial variation of COD and NH4-N in the first-stage constructed wetland demonstrated that entrainment of air during draining of constructed wetland could strengthen the removal of COD and NH4-N. Temperature had no significant effect on COD degradation while obviously affected the removal of NH4-N.

Sign in / Sign up

Export Citation Format

Share Document