A strategy in wastewater treatment process for significant reduction of excess sludge production

2002 ◽  
Vol 45 (12) ◽  
pp. 127-134 ◽  
Author(s):  
N. Shiota ◽  
A. Akashi ◽  
S. Hasegawa
Keyword(s):  
Wastewater Treatment ◽  
Treatment Process ◽  
Pilot Scale ◽  
Aeration Tank ◽  
Excess Sludge ◽  
Wastewater Treatment Process ◽  
Conventional Activated Sludge ◽  
New Process ◽  
Treatment Step ◽  
Sludge Production

A novel wastewater treatment process (S-TE PROCESS®) with significantly reduced production of excess sludge has been developed. The process consists of two different stages, one for a biological wastewater treatment and the other for a thermophilic aerobic digestion of the resulting sludge. A portion of return sludge from the wastewater treatment step is injected into a thermophilic aerobic sludge digester (TASD), in which the injected sludge is solubilized by the action of thermophilic aerobic bacteria. The solubilized sludge is returned to the aeration tank in the wastewater treatment step for its further degradation. Pilot-scale facilities of the S-TE process and the conventional activated sludge process as a control, both treating the same industrial wastewater, were comparatively operated for totally 270 days. As a result, 93% reduction in overall excess sludge production was achieved in the S-TE operation. The SS solubilization rate in TASD was stable at around 30%. Only a slight increase in the effluent SS and TOC concentrations was observed compared with those of the control facility. Otherwise the removal efficiency of TOC was approximately 95% for both plants. A full-scale plant treating domestic sewage was operated for three years, showing 75% reduction of overall excess sludge production. It was concluded that the new process was feasible.

An innovative approach to reduce excess sludge production in the activated sludge process

1994 ◽  
Vol 30 (9) ◽  
pp. 11-20 ◽  
Author(s):  
H. Yasui ◽  
M. Shibata
Keyword(s):  
Activated Sludge ◽  
Biomass Concentration ◽  
Experimental Period ◽  
Aeration Tank ◽  
Activated Sludge Process ◽  
Biological Degradation ◽  
Excess Sludge ◽  
Conventional Activated Sludge ◽  
New Process ◽  
Sludge Production

A new process has been developed to reduce excess sludge production, in which both excess sludge digestion and wastewater treatment are conducted simultaneously in the same aeration tank. The ozonation enhances biological degradation of the activated sludge, which is decomposed in a subsequent biological treatment. A considerable amount of biomass is mineralized biologically in proportion to the amount of recirculated biomass from the ozonation stage to the biological stage. It was observed that the amount of excess sludge is reduced to nearly zero when 1.2 kg/m3-aeration tank volume of biomass is recirculated in a day from the biological stage to the ozonation stage at a BOD loading of 1.0 kg/m3/d. A biomass concentration of 4200 mg/L was maintained at 1.0 kg-BOD/m3/d without drawing excess sludge for 6 weeks of experimental period under ozone dose of 0.05 g-O3/g-SS and recirculation rate at 0.3 d−1. Only a limited difference in the effluent quality was observed between the new process and the conventional activated sludge process.

Biological wastewater treatment by a bioreactor with repeated coupling of aerobes and anaerobes aiming at on-site reduction of excess sludge

2006 ◽  
Vol 53 (9) ◽  
pp. 71-77 ◽  
Author(s):  
Anfeng Yu ◽  
Quan Feng ◽  
Zehua Liu ◽  
Yunan Zhou ◽  
Xin-Hui Xing
Keyword(s):  
Wastewater Treatment ◽  
Treatment Process ◽  
Removal Rate ◽  
Settling Tank ◽  
Technological Innovations ◽  
Biological Wastewater Treatment ◽  
Excess Sludge ◽  
Wastewater Treatment Process ◽  
Complex Microbial Community ◽  
Continuous Running

Activated sludge has been widely used in wastewater treatment throughout the world. However, the biggest disadvantage of this method is the by-production of excess sludge in a large amount, resulting in difficulties in operation and high costs for wastewater treatment. Technological innovations for wastewater treatment capable of reducing excess sludge have thus become research topics of interest in recent years. In our present research, we developed a new biological wastewater treatment process by repeated coupling of aerobes and anaerobes (rCAA) to reduce the excess sludge during the treatment of wastewater. During 460-day continuous running, COD (300–700 mg/L) and TOC (100–350 mg/L) were effectively removed, of which the removal rate was above 80 and 90%, respectively. SS in the effluent was 13 mg/L on average in the rCAA bioreactor without a settling tank. The on-site reduction of the excess sludge in the rCAA might be contributed by several mechanisms. The degradation of the grown aerobes after moving into the anaerobic regions was considered to be one of the most important factors. Besides, the repeatedly coupling of aerobes and anaerobes could also result in a complex microbial community with more metazoans and decoupling of the microbial anabolism and catabolism.

MARAPUR—a new process combination for the optimization of MBR

2008 ◽  
Vol 58 (11) ◽  
pp. 2101-2107
Author(s):  
F. Klegraf ◽  
J. Lahnsteiner
Keyword(s):  
Wastewater Treatment ◽  
Treatment Process ◽  
Cross Flow ◽  
Mesh Size ◽  
Main Process ◽  
Biological Wastewater Treatment ◽  
Wastewater Treatment Process ◽  
Effective Measure ◽  
New Process ◽  
Process Combination

The MARAPUR concept is a biological wastewater treatment process based on the MBR functional principle. The ultrafiltration of activated sludge takes place in pressure-driven hollow fiber membranes. The vertical membrane modules are installed compactly in a MEGAMODUL. The permeate extraction is accomplished in the cross-flow, which is supported by rinsing aeration. The main process advantages are high filtration performance, excellent operation reliability provided by wastewater fine sieving and reduced cleaning chemicals demand. Wastewater fine sieving with a mesh size of 0.25 mm is an effective measure against membrane clogging by hair and fibers.

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.

Characterization of membrane foulants in a pilot-scale tunnel construction wastewater treatment process

2014 ◽  
Vol 171 ◽  
pp. 384-388 ◽  
Author(s):  
Jae-Hyun Lee ◽  
Jong-Oh Kim ◽  
Se-Uk Jeong ◽  
Hyun Uk Cho ◽  
Kyung Hwa Cho ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Treatment Process ◽  
Pilot Scale ◽  
Tunnel Construction ◽  
Wastewater Treatment Process

A study on the effects of ozone dosage on dissolved-ozone flotation (DOF) process performance

2015 ◽  
Vol 71 (9) ◽  
pp. 1423-1428 ◽  
Author(s):  
Xin Jin ◽  
Pengkang Jin ◽  
Xiaochang Wang
Keyword(s):  
Organic Matter ◽  
Wastewater Treatment ◽  
Wastewater Treatment Plant ◽  
Treatment Process ◽  
Treatment Plant ◽  
Pilot Scale ◽  
Secondary Effluent ◽  
Process Performance ◽  
Wastewater Treatment Process ◽  
Organic Matter Removal

Dissolved-ozone flotation (DOF) is a tertiary wastewater treatment process, which combines ozonation and flotation. In this paper, a pilot-scale DOF system fed by secondary effluent from a wastewater treatment plant (WWTP) in China was used to study the effect of ozone dosage on the DOF process performance. The results show that an ozone dosage could affect the DOF performance to a large extent in terms of color and organic matter removal as well as disinfection performance. The optimal color and organic matter removal was achieved at an ozone dosage of 0.8 mg/l. For disinfection, significant improvement in performance could be achieved only when the organic matter removal was optimal. The optimal ozone dosage of at least 1.6 mg/l was put forward, in this case, in order to achieve the optimal color, turbidity, organic matter and disinfection performance.

scholarly journals Wastewater Treatment From Pharmaceutical Substances With Filamentous Fungi

2021 ◽  
Author(s):  
◽  
Brigita Daļecka
Keyword(s):  
Wastewater Treatment ◽  
Fluidized Bed ◽  
Filamentous Fungi ◽  
Municipal Wastewater ◽  
Treatment Process ◽  
Pilot Scale ◽  
Municipal Wastewater Treatment ◽  
Wastewater Treatment Process ◽  
Fungal Strains ◽  
Pharmaceutical Substances

The ever-increasing concern about the widespread occurrence of pharmaceutical substances in the aquatic environment has been recognized as an emerging environmental issue, as it can cause undesirable effects on the ecosystem and human health. The current wastewater treatment methods are not designed to treat municipal wastewater from the contamination of various pharmaceutical substances. As a result, pharmaceuticals can enter the environment and pose a threat to life forms. Therefore, it is important to enhance the classical wastewater treatment process in order to meet the challenges by advancing the technologies. Currently, the biological treatment method with filamentous fungi has been considered a promising, cost-effective, and environmentally friendly method for removing pharmaceutical substances from municipal wastewater. Thesis “Wastewater Treatment from Pharmaceutical Substances with Filamentous Fungi” demonstrates the potential application of fungi in removing pharmaceutical substances and their expedience to incorporate into the classical municipal wastewater treatment process. The investigation focused on selecting suitable fungal strains that could adapt without adjusting physico-chemical parameters and compete with the microbial community in the municipal wastewater. Further, the Thesis investigated whether fungal strains could reduce nutrients and pharmaceutical substances in lab-scale and pilot-scale setup and the mechanisms of pharmaceutical substance removal. The research consists of two main stages. In the first stage, the batch-scale experiments were carried out under laboratory conditions, finding out the most suitable fungal strains for the removal of pharmaceutical substances from wastewater. The results demonstrated that fungi compete with each other, since higher removal efficiency was observed if the fungi were grown individually. Batch-scale experiments showed that Trametes versicolor (a laboratory strain) and Aspergillus luchuensis (an environmental isolate from a municipal wastewater treatment plant) can be promising strains for removing pharmaceutical substances in a non-sterile municipal wastewater treatment without the adjustment of pH level. Therefore, these strains were used for further study. In the second stage, the pilot-scale system with a fungal fluidized bed pelleted bioreactor was developed. The results demonstrated a high potential to remove phosphorus from municipal wastewater efficiently and successfully under a batch scale experiment with non-sterile municipal wastewater, while the results from the fluidized bed bioreactor did not demonstrate any significant decrease of phosphorus. Additionally, the fluidized pelleted bioreactor was optimized to perceive bioaugmentation as a strategy with the frequent addition of fungal biomass. The results from the optimization process showed that bioaugmentation is a relatively efficient approach to build on fungi in the fluidized pelleted bioreactor. Furthermore, the results from the AI-based platform with modeling study showed that optimization of bioaugmentation with fungi increases the removal efficiency of pharmaceutical substances from non-sterile municipal wastewater. The author of this study showed that both the literature review and the results from the batch and pilot-scale experiments provided new knowledge that can be used for future investigations of wastewater treatment with fungi. The Thesis will help to improve and better understand the possible application of fungi in the municipal wastewater treatment process.

Fate of oestrogenic compounds and identification of oestrogenicity in a wastewater treatment process

2006 ◽  
Vol 53 (11) ◽  
pp. 51-63 ◽  
Author(s):  
N. Nakada ◽  
M. Yasojima ◽  
Y. Okayasu ◽  
K. Komori ◽  
H. Tanaka ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Column Chromatography ◽  
Treatment Process ◽  
Wastewater Treatment Plants ◽  
Instrumental Analysis ◽  
Aeration Tank ◽  
Wastewater Treatment Process ◽  
Vitro Assay ◽  
Wastewater Samples

Understanding of the fate of oestrogen and oestrogenic compounds is important in improving the removal efficiency for oestrogens in wastewater treatment plants (WWTPs). In this study an attempt was made to clarify the fate of oestrogen, oestrogen sulphates, and oestrogenic compounds (synthetic oestrogen, nonylphenol and its relatives) by an instrumental analysis, and the fate of oestrogenicity by an in vitro assay. The investigation was conducted in an activated sludge WWTP in winter and summer, focusing on identification of the primary substances that induce oestrogenicity. Wastewater samples were analysed by employing the silica-gel fractionation technique in conjunction with two-step column chromatography. The results revealed that, in winter, the WWTP efficiencies for the removal of nitrogen and oestrogens decreased and the oestrone level increased with the progress of the treatment. Oestrone and oestrogenic substances are likely to circulate between the aeration tank and the final sedimentation tank. In summer, however, these compounds were effectively removed in the WWTP. The results of the column chromatography coupled with the bioassay suggested that E1 and E2 are the predominant contributors to the oestrogenicity in the influent, return sludge and effluent of the WWTP. The measurement by the instrumental analysis supported these findings.

Sign in / Sign up

Export Citation Format

Share Document