scholarly journals Pilot-Scale Airlift Bioreactor with Function-Enhanced Microbes for the Reduction of Refinery Excess Sludge

2021 ◽  
Vol 18 (13) ◽  
pp. 6742
Author(s):  
Hongyan Mu ◽  
Min Zhang ◽  
Shanshan Sun ◽  
Zhaozheng Song ◽  
Yijing Luo ◽  
...  
Keyword(s):  
Removal Rate ◽  
Oxygen Demand ◽  
Standard Addition ◽  
Pilot Scale ◽  
Airlift Bioreactor ◽  
Sludge Reduction ◽  
Low Carbon ◽  
Excess Sludge ◽  
Emission Standard ◽  
And Function

A pilot-scale airlift bioreactor (ALBR) system was built and operated continuously for refinery excess sludge (RES) reduction. Combined ALBR and function-enhanced microbes (composed of photosynthetic bacteria and yeast) were integrated into the system. The pilot-scale ALBR was operated for 62 days, and the start-up time was 7 d. Continuous operation showed that the sludge reduction efficiency was more than 56.22%, and the water quality of the effluent was satisfactory. This study focused on investigating the effects of hydraulic retention time (HRT) on the stability of the system and the effect of sludge reduction. Under different HRT conditions of 40, 26.7, 20, and 16 h, the sludge reduction rates reached 56.22%, 73.24%, 74.09%, and 69.64%, respectively. The removal rates of chemical oxygen demand (COD) and total nitrogen (TN) decreased with decreasing HRT, whereas the removal rate of NH4+-N increased. The removal rate of total phosphorus (TP) was approximately 30%. Results indicate that the ALBR and function-enhanced microbe system can reduce sludge and treat sewage simultaneously, and the effluent is up to the national emission standard. Addition of function-enhanced microbes can promote the degradation of petroleum hydrocarbon substances in the sludge, especially alkanes with low carbon numbers. This study suggests that the optimal HRT for the system is 16 h. The total operation cost of the ALBR combined with the function-enhanced microbe system can be reduced by 50% compared with the cost of direct treatment of the RES system.

A new oxic-settling-anaerobic (NOSA®) activated sludge process for minimizing excess sludge in secondary biological treatment plants: a pilot-scale evaluation of the absorption–biodegradation process

2013 ◽  
Vol 68 (3) ◽  
pp. 530-536 ◽  
Author(s):  
Ke Wu ◽  
Shi-yu Li ◽  
Feng Jiang ◽  
Jun Wang ◽  
Guang-li Liu ◽  
...  
Keyword(s):  
Biological Treatment ◽  
Wastewater Treatment Plants ◽  
Pilot Trial ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Sludge Reduction ◽  
Excess Sludge ◽  
Sludge Dewatering ◽  
New Process ◽  
Biodegradation Process

This study compared the sludge reduction performance of a new oxic-settling-anaerobic (NOSA) process with that of a conventional adsorption–biodegradation process. A 50 m3/d pilot trial system with two different process configurations was operated for 6 months. The NOSA process functioned effectively in removing both chemical oxygen demand and nitrogen with the efficiencies of 86 and 92.5%, respectively, which reduced approximately 40% of the excess sludge. In this research, 0.77 kg volatile suspended solids/d sludge vanished in the anaerobic tank, which accounted for 58.9% of the total sludge loss in the NOSA process. Economic calculation suggests that the new process can dramatically upgrade the sludge reduction in wastewater treatment plants without a digestion device, and the investment for fundamental upgrading can be recovered in 5–6 years by cutting the costs of excess sludge dewatering and disposal treatment.

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.

Comparison between ozonation and the OSA process: analysis of excess sludge reduction and biomass activity in two different pilot plants

2012 ◽  
Vol 66 (1) ◽  
pp. 185-192 ◽  
Author(s):  
Michele Torregrossa ◽  
Gaetano Di Bella ◽  
Daniele Di Trapani
Keyword(s):  
Municipal Wastewater ◽  
Process Analysis ◽  
Treatment Plant ◽  
Pilot Scale ◽  
Anaerobic Sludge ◽  
Sludge Reduction ◽  
Excess Sludge ◽  
Biomass Activity ◽  
Excess Sludge Reduction ◽  
Ozone Contactor

The excess biomass produced during biological treatment of municipal wastewater represents a major issue worldwide, as its disposal implies environmental, economic and social impacts. Therefore, there has been a growing interest in developing technologies to reduce sludge production. The main proposed strategies can be categorized according to the place inside the wastewater treatment plant (WWTP) where the reduction takes place. In particular, sludge minimization can be achieved in the wastewater line as well as in the sludge line. This paper presents the results of two pilot scale systems, to evaluate their feasibility for sludge reduction and to understand their effect on biomass activity: (1) a pilot plant with an ozone contactor in the return activated sludge (RAS) stream for the exposition of sludge to a low ozone dosage; and (2) an oxic-settling-anaerobic (OSA) process with high retention time in the anaerobic sludge holding tank have been studied. The results showed that both technologies enabled significant excess sludge reduction but produced a slight decrease of biomass respiratory activity.

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.

scholarly journals Correlation between the uncoupling metabolism induced by 2,4,6-trichlorophenol and sludge toxicity in sequence batch reactors

2020 ◽  
Vol 82 (10) ◽  
pp. 1971-1981
Author(s):  
Xiurong Chen ◽  
Quanling Lu ◽  
Shanshan Wang ◽  
Xiaoli Sun ◽  
Qiuyue Li ◽  
...  
Keyword(s):  
Suspended Solids ◽  
Removal Rate ◽  
Polyacrylamide Gel Electrophoresis ◽  
Oxygen Demand ◽  
Cod Removal ◽  
Batch Reactors ◽  
Sludge Reduction ◽  
Intracellular Proteins ◽  
Operation Period ◽  
Cod Removal Rate

Abstract The correlation between sludge reduction induced by 2,4,6-trichlorophenol (2,4,6-TCP) as an uncoupler and sludge toxicity was investigated in sequence batch reactors over a 100-d operation period. The influent concentrations of 2,4,6-TCP tested were 10 mg/L, 30 mg/L, and 50 mg/L. Sludge reduction, chemical oxygen demand (COD) removal rate, and sludge toxicity were measured. The results showed that from 30 to 80 d, when the COD removal rate was at an acceptable level, the sludge reduction levels for the 10 mg/L, 30 mg/L, and 50 mg/L groups were 9.7%, 31.6%, and 41.5%, respectively, and the average sludge toxicity values were 24.2%, 38.0%, and 53.0%, respectively. Sludge reduction was positively correlated with sludge toxicity. The two-dimensional polyacrylamide gel electrophoresis/results showed that extracellular and intracellular proteins secreted by the activated sludge during uncoupling metabolism were positively correlated with sludge toxicity. Taking the COD removal rate, sludge reduction, and sludge toxicity into consideration, the optimal influent concentration of the uncoupler 2,4,6-TCP was 30 mg/L when the initial mixed liquid suspended solids of sludge was 2,500 mg/L.

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