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.

Sludge Reduction in Anaerobic-Anoxic-Oxic System by Lysis-Cryptic Growth Using Ultrasound Pretreatment

2014 ◽  
Vol 955-959 ◽  
pp. 2687-2691 ◽  
Author(s):  
Zhao Hui Meng ◽  
Wan Qian Guo ◽  
Shan Shan Yang ◽  
Shui Li Yu
Keyword(s):  
Nutrient Removal ◽  
Biological Treatment ◽  
Oxygen Demand ◽  
Cod Removal ◽  
Sludge Reduction ◽  
Excess Sludge ◽  
Reduction Effect ◽  
Excess Sludge Reduction ◽  
Biological Treatment System ◽  
Ultrasound Pretreatment

In this study, sludge reduction by ultrasound combining anaerobic-anoxic-oxic system (AAO) was developed and examined. Compared with AAO process, 38.07, 46.07 and 50.98% of excess sludge reduction could be obtained by ultrasonic combining AAO system (sludge return ratios of 40%, 60%, and 80%). When the sludge return ratio is 60%, ultrasound combining AAO system can achieve the best sludge reduction effect. Chemical oxygen demand (COD) removal rates of ultrasound combining AAO system were 88.21, 89.77, and 90.31%, respectively. The introduction of sludge disruption by ultrasound pretreatment did not affect the COD removal ability of the AAO system, whereas increased in the COD removal efficiency. This combined biological treatment system could realize sludge reduction and improve nutrient removal efficiencies.

Sludge as source of energy and revenue

2004 ◽  
Vol 50 (9) ◽  
pp. 197-204 ◽  
Author(s):  
T.I. Onyeche
Keyword(s):  
Wastewater Treatment Plants ◽  
Biogas Production ◽  
Oxygen Demand ◽  
Economic Benefits ◽  
Sludge Reduction ◽  
Sludge Dewatering ◽  
Sludge Treatment ◽  
Extra Energy ◽  
Treatment And Disposal ◽  
Low Pressures

Sludge is a residue/product from wastewater treatment plants and contains most of the contaminants released during human activities. Some stringent environmental regulations on sludge treatment and disposal exist in many countries. This has resulted in increasing interest in sludge treatment methods that encourage sludge reduction and improvement in biogas production during anaerobic digestion processes. This work demonstrates the first exploitation of valuable energy from homogenised sludge at technical scale with mass reduction. The optimal combination of sludge homogenisation at relatively low pressures using a modified high-pressure homogeniser led to the success of this unique project. Results showed that about 30% more energy could be obtained from thickened and disrupted sludge than from untreated samples. The energy produced was higher than that invested during disruption and digestion processes. About 23% sludge reduction was also observed with no increase in chemical oxygen demand. This new process can produce extra energy for local electrification and heating the digester while the sludge reduction provides economic benefits. Concentration of sludge causes reduction in investment cost on digester as well as reduction in operational time for sludge dewatering.

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.

The Characteristics of Community Wastewater Biological Treatment Processes in Taiwan

1986 ◽  
Vol 18 (7-8) ◽  
pp. 289-296
Author(s):  
C. F. Ouyang ◽  
T. J. Wan
Keyword(s):  
Biological Treatment ◽  
Wastewater Treatment Plants ◽  
Oxygen Demand ◽  
Field Investigation ◽  
Oxidation Ditch ◽  
Trickling Filter ◽  
Rotating Biological Contactor ◽  
Treatment Processes ◽  
Treatment Characteristics ◽  
Sludge Thickening

This study investigated and compared the treatment characteristics of three different kinds of biological wastewater treatment plants (including rotating biological contactor, trickling filter and oxidation ditch) which are currently operated in Taiwan. The field investigation of this study concentrated on the following items: the performance of biological oxygen demand (BOD) and suspended solids (SS) removal; the sludge yield rate of BOD removal; the settleability of sludge solids; the properties of sludge thickening; the power consumption and land area requirement per unit volume of wastewater. Finally, based on the results of the field investigation, a comparison of the treatment characteristics of the three different biological treatment processes was evaluated.

scholarly journals Full-scale performance of selected starch-based biodegradable polymers in sludge dewatering and recommendation for applications

2017 ◽  
Vol 77 (1) ◽  
pp. 7-16 ◽  
Author(s):  
Kuangxin Zhou ◽  
Johan Stüber ◽  
Rabea-Luisa Schubert ◽  
Christian Kabbe ◽  
Matthias Barjenbruch
Keyword(s):  
Biodegradable Polymers ◽  
Wastewater Treatment Plants ◽  
Pilot Scale ◽  
Full Scale ◽  
Municipal Sewage ◽  
Municipal Sewage Sludge ◽  
Operational Parameters ◽  
Sludge Dewatering ◽  
Dewatered Sludge ◽  
Green Polymers

Abstract Agricultural reuse of dewatered sludge is a valid route for sludge valorization for small and mid-size wastewater treatment plants (WWTPs) due to the direct utilization of nutrients. A more stringent of German fertilizer ordinance requires the degradation of 20% of the synthetic additives like polymeric substance within two years, which came into force on 1 January 2017. This study assessed the use of starch-based polymers for full-scale dewatering of municipal sewage sludge. The laboratory-scale and pilot-scale trials paved the way for full-scale trials at three WWTPs in Germany. The general feasibility of applying starch-based ‘green’ polymers in full-scale centrifugation was demonstrated. Depending on the sludge type and the process used, the substitution potential was up to 70%. Substitution of 20–30% of the polyacrylamide (PAM)-based polymer was shown to achieve similar total solids (TS) of the dewatered sludge. Optimization of operational parameters as well as machinery set up in WWTPs is recommended in order to improve the shear stability force of sludge flocs and to achieve higher substitution potential. This study suggests that starch-based biodegradable polymers have great potential as alternatives to synthetic polymers in sludge dewatering.

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.

Using excess sludge as carbon source for enhanced nitrogen removal and sludge reduction with hydrolysis technology

2010 ◽  
Vol 62 (7) ◽  
pp. 1536-1543 ◽  
Author(s):  
Yong-Qing Gao ◽  
Yong-Zhen Peng ◽  
Jing-Yu Zhang ◽  
Jian-Long Wang ◽  
Liu Ye
Keyword(s):  
Carbon Source ◽  
Nitrogen Removal ◽  
Wastewater Treatment Plants ◽  
Reduction Rate ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Batch Reactors ◽  
Sludge Reduction ◽  
Zero Order Kinetics ◽  
Soluble Chemical Oxygen Demand

In order to improve the nitrogen removal efficiency and to achieve the sludge reduction in traditional wastewater treatment plants, a combined hydrolysis-anoxic-oxic (H-A-O) pilot-scaled reactor was used in this study to investigate the possibility and validity of using excess activated sludge (EAS) fermentation liquids to enhance the nitrogen removal. The results clearly showed that sludge acidification rate in fermentation reactor can reach to 43.2%. The percentages of acetic acid, propionic acid and butyric acid in the fermentation liquids were 68.4, 25.3 and 6.3%, respectively, while those in domestic wastewater were 73.0, 12.2 and 13.8%, respectively. Bioavailability of soluble chemical oxygen demand (SCOD) from fermentation liquids and domestic wastewater were investigated in batch reactors with nitrate as the electron accepter as well. The corresponding specific denitrification rates were 0.15 g NO3−-N/g VSS d−1 and 0.09 g NO3−-N/g VSS d−1. When the substances were enough, the denitrification reaction appeared to follow the zero-order kinetics. The results also showed that, when the H-A-O pilot-scaled reactor was operated continuously and sludge fermentation liquids were applied as additional carbon source in the A-O reactor, the removal efficiencies of SCOD, NH4+-N and total nitrogen (TN) were higher than 90, 95 and 79%, respectively. EAS reduction rate in this system was able to reach 40.4%, and the sludge VSS/SS ratio decreased from 0.82 to 0.59 after hydrolysis step.

A Novel Method for Biological Treatment of Bleached Kraft Mill Wastewaters

1994 ◽  
Vol 29 (5-6) ◽  
pp. 295-301 ◽  
Author(s):  
Andrew Strehler ◽  
Thomas Welander
Keyword(s):  
Biological Treatment ◽  
Oxygen Demand ◽  
Alkaline Treatment ◽  
Pilot Scale ◽  
Cod Removal ◽  
Kraft Mill Effluent ◽  
Kraft Mill ◽  
Temperature Levels ◽  
C 50 ◽  
Suspended Carrier

Removal of adsorbable organic halogen (AOX) and chemical oxygen demand (COD) from bleached kraft mill effluent was investigated in laboratory and pilot scale aerobic suspended carrier reactors and abiotic thermo-alkaline reactors. Laboratory treatment focused on determination of loading capacity of the suspended carrier process and operation of the process at elevated temperature and pH values in order to combine abiotic thermo-alkaline dechlorination and biological treatment in one reactor. At pH 7, 37°C and hydraulic retention times (HRTs) longer than 3.5 hours, a maximum COD removal of 55% was achieved in the suspended carrier process. The COD conversion rate at the minimum HRT was 2.6 kg COD/(m3*d). The suspended carrier treatment was operated successfully at pH 9.0 and 45°C and at pH 7.0 and 50°C with over 50 percent COD removal with a HRT of four hours. The AOX removal achieved at pH 9 and 45°C (50%) was significantly higher than the removal at pH 7 and 37°C (39%), most certainly because of an increased abiotic dechlorination at the higher pH and temperature levels. Sequential thermo-alkaline and biological treatment were studied on a pilot scale. Tbermo-alkaline treatment at pH 10, 54°C and a HRT of two hours followed by biological treatment at pH 8, 35°C and a HRT of four hours, removed almost 80% of AOX and 50% of COD from the kraft mill effluent.

Biological sludge solubilisation for reduction of excess sludge production in wastewater treatment process

2006 ◽  
Vol 54 (5) ◽  
pp. 51-58 ◽  
Author(s):  
T. Yamaguchi ◽  
Y. Yao ◽  
Y. Kihara
Keyword(s):  
Wastewater Treatment ◽  
Biological Treatment ◽  
Wastewater Treatment Plants ◽  
Experimental Period ◽  
Excess Sludge ◽  
Wastewater Treatment Process ◽  
Biological Sludge ◽  
Scale Experiment ◽  
Sludge Production

A novel sludge disintegration system (JFE-SD system) was developed for the reduction of excess sludge production in wastewater treatment plants. Chemical and biological treatments were applied to disintegrate excess sludge. At the first step, to enhance biological disintegration, the sludge was pretreated with alkali. At the second step, the sludge was disintegrated by biological treatment. Many kinds of sludge degrading microorganisms integrated the sludge. The efficiency of the new sludge disintegration system was confirmed in a full-scale experiment. The JFE-SD system reduced excess sludge production by approximately 50% during the experimental period. The quality of effluent was kept at quite a good level. Economic analysis revealed that this system could significantly decrease the excess sludge treatment cost.

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