Feasibility study of mechanically disintegrated sludge and recycle in the activated-sludge process

2002 ◽  
Vol 46 (10) ◽  
pp. 97-104 ◽  
Author(s):  
P. Camacho ◽  
V. Geaugey ◽  
P. Ginestet ◽  
E. Paul
Keyword(s):  
Activated Sludge ◽  
Mechanical Treatment ◽  
Aeration Tank ◽  
Urban Wastewater ◽  
Combined System ◽  
Action Mechanisms ◽  
First Pass ◽  
High Pressure Homogenizer ◽  
Biological Performance ◽  
Sludge Settling

The action mechanisms and performances of a combined system associating activated sludge and mechanical treatment (High Pressure Homogenizer) were evaluated for urban wastewater. Discontinuous experiments showed that the energy applied at the first pass was high enough to modify the sludge particulate fraction (high COD release) but without cell lysis. The applied shear forces led to a progressive cell break up (maximal COD release 90% total COD). Continuous experiments showed less than 20% reduction in sludge production (compared to a control run under the same loading conditions YTSS = 0.35 g TSS.g−1CODremoved through the application of mechanical treatment (stress frequency = 0.2 d−1). Recycling of mechanical treated sludge to the aeration tank induced a slight increase in effluent TSS, but the biological performance seemed to be maintained. Significant improvements in sludge settling characteristics were observed.

Minimization of sludge production in biological processes: an alternative solution for the problem of sludge disposal

2002 ◽  
Vol 46 (10) ◽  
pp. 63-70 ◽  
Author(s):  
S. Deleris ◽  
V. Geaugey ◽  
P. Camacho ◽  
H. Debellefontaine ◽  
E. Paul
Keyword(s):  
Biological Treatment ◽  
Reduction Process ◽  
Aeration Tank ◽  
Urban Wastewater ◽  
Combined System ◽  
Active Biomass ◽  
Sludge Disposal ◽  
Autotrophic Biomass ◽  
Sludge Settling ◽  
Sludge Production

A combined system associating activated sludge and ozonation was evaluated for the treatment of urban wastewater. Experiments have shown that 70% reduction in sludge production can be reached (compared to a reference system running in low loaded conditions Yobs = 0.28 g VSS.g COD-1) by applying an ozone dosage of 0.05 g O3/g VSStreated. Recycling of the ozonated sludge to the aeration tank induces a slight increase in effluent COD, but the biological treatment performance is maintained. Nitrification capabilities are not altered by the sludge reduction process and active biomass measurements revealed that autotrophic biomass seems to be less affected than the heterotrophs. Significant improvements in sludge settling characteristics are observed.

New combined system of biological process and intermittent ozonation for advanced wastewater treatment

1998 ◽  
Vol 38 (8-9) ◽  
pp. 145-153 ◽  
Author(s):  
T. Kamiya ◽  
J. Hirotsuji
Keyword(s):  
Biological Treatment ◽  
Biological Process ◽  
Waste Water Treatment ◽  
Aeration Tank ◽  
Excess Sludge ◽  
Combined System ◽  
Remarkable Effect ◽  
Effluent Quality ◽  
Treatment Processes ◽  
Sludge Settling

A new system combining both biological treatment and intermittent ozonation has been developed to reduce excess sludge production with a small amount of ozone. In this system, activated sludge in the aeration tank was circulated via intermittent ozonation. Experimental results have shown that 50% of the sludge generation was cut down with only 30% of the ozone dose required for continuous ozonation. Furthermore, the process had a remarkable effect on maintaining the sludge settling characteristics. The sludge ozonation was almost of little influence on the effluent quality though the slight degradation of effluent quality was observed in few cases. These facts suggested the effectiveness of the newly proposed system for saving costs and stabilizing treatment performance of biological waste water treatment processes.

Effects of potassium ion on sludge settling, dewatering and effluent properties

1998 ◽  
Vol 37 (4-5) ◽  
pp. 317-324 ◽  
Author(s):  
Sudhir N. Murthy ◽  
John T. Novak
Keyword(s):  
Activated Sludge ◽  
Field Studies ◽  
Potassium Ion ◽  
Potassium Ions ◽  
Nutrient Requirements ◽  
Sludge Dewatering ◽  
Capillary Suction ◽  
Sludge Flocs ◽  
Sludge Properties ◽  
Sludge Settling

Potassium ions appear to play an important role in determining the nature of activated sludge flocs. Relative to sodium, the concentration of potassium ions in most industrial activated sludge is typically low. Laboratory and field studies were conducted to examine the influence of potassium on activated sludge properties. The concentration of potassium affected the concentration of readily extractable (slime) proteins in the floc and the proteins in the surrounding solution. In laboratory tests, an increase in this cation's concentration beyond nutrient requirements impeded sludge dewatering properties as measured by capillary suction time (CST) and specific resistance to filtration (SRF) and associated with an increase in soluble protein. An increase in effluent total organic carbon and effluent turbidity was observed at higher concentrations of this ion. Conversely, an increase in concentration of potassium ion improved the settling properties of sludge with low equivalent monovalent to divalent cation ratio.

An investigation into studying of the activated sludge foaming potential by using physicochemical parameters

2002 ◽  
Vol 46 (1-2) ◽  
pp. 525-528 ◽  
Author(s):  
K. Hladikova ◽  
I. Ruzickova ◽  
P. Klucova ◽  
J. Wanner
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Physicochemical Parameters ◽  
Wastewater Treatment Plants ◽  
Physicochemical Characteristics ◽  
Full Scale ◽  
Aeration Tank ◽  
Foam Formation ◽  
Individual Parameter

This paper examines how the physicochemical characteristics of the solids are related to foam formation and describes how the foaming potential of full-scale plants can be assessed. The relations among activated sludge and biological foam hydrophobicity, scum index, aeration tank cover and filamentous population are evaluated. Individual parameter comparison reveals the scumming intensity can be estimated only on the assumption that foams is already established. None of the above mentioned characteristics can be reliably used to predict the foaming episodes at wastewater treatment plants.

Effect of important operational parameters on performance of coarse pore filtration activated sludge process

2002 ◽  
Vol 46 (9) ◽  
pp. 229-236 ◽  
Author(s):  
M.R. Alavi Moghaddam ◽  
H. Satoh ◽  
T. Mino
Keyword(s):  
Activated Sludge ◽  
Aeration Tank ◽  
Activated Sludge Process ◽  
Operational Parameters ◽  
Solid Retention Time ◽  
Effluent Quality ◽  
Membrane Pores ◽  
Filtration Membrane ◽  
Operation Pressure ◽  
Filter Clogging

A coarse pore filter can be applied inside the aeration tank instead of sedimentation tank for liquid separation from the sludge. It has pores, which are irregular in shape, and much bigger than micro-filtration membrane pores in size. The objective of the study was to investigate the effect of important operational parameters such as flux, aeration intensity, and solid retention time (SRT) on the performance of the coarse pore filtration activated sludge process. The effect of these parameters was studied in laboratory scale experiments. It was found that the flux had a significant role in the effluent quality of this system. The effluent SS and turbidity were not changed significantly at different aeration intensities. Three SRTs, 10, 30 and longer days (without excess sludge) were used for three reactors to check the effect of this parameter on the system performance. The results of the reactors with SRTs about 10 and 30 days have shown very good effluent quality without any filter clogging for more than 4 months operation. For the reactor with long SRT, the filter clogging was observed after about 80 days of operation, which caused the increase of the operation pressure and deterioration in the effluent quality for a few days.

Calibrating a side-stream membrane bioreactor using Activated Sludge Model No. 1

2005 ◽  
Vol 52 (10-11) ◽  
pp. 359-367 ◽  
Author(s):  
T. Jiang ◽  
X. Liu ◽  
M.D. Kennedy ◽  
J.C. Schippers ◽  
P.A. Vanrolleghem
Keyword(s):  
Activated Sludge ◽  
Biological Behaviour ◽  
Activated Sludge Model ◽  
Effluent Quality ◽  
Side Stream ◽  
Steady State Operation ◽  
Autotrophic Biomass ◽  
Biological Performance ◽  
Activated Sludge Processes ◽  
Influent Wastewater

Membrane bioreactors (MBRs) are attracting global interest but the mathematical modeling of the biological performance of MBRs remains very limited. This study focuses on the modeling of a side-stream MBR system using the Activated Sludge Model No. 1 (ASM1), and compares the results with the modeling of traditional activated sludge processes. ASM1 parameters relevant for the long-term biological behaviour in MBR systems were calibrated (i.e. YH = 0.72gCOD/gCOD, YA = 0.25gCOD/gN, bH = 0.25d−1, bA = 0.080d−1 and fP = 0.06), and generally agreed with the parameters in traditional activated sludge processes, with the exception that a higher autotrophic biomass decay rate was observed in the MBR. Influent wastewater characterization was proven to be a critical step in model calibration, and special care should be taken in characterizing the inert particulate COD (XI) concentration in the MBR influent. It appeared that the chemical–biological method was superior to the physical–chemical method. A sensitivity analysis for steady-state operation and DO dynamics suggested that the biological performance of the MBR system (the sludge concentration, effluent quality and the DO dynamics) are very sensitive to the parameters (i.e. YH, YA, bH, bA μmaxH and μmaxA), and influent wastewater components (XI, Ss, Xs and SNH).

Evaluation of ozonation and cryptic growth for biosolids management in wastewater treatment

1999 ◽  
Vol 39 (10-11) ◽  
pp. 155-158 ◽  
Author(s):  
E. Egemen ◽  
J. Corpening ◽  
J. Padilla ◽  
R. Brennan ◽  
N. Nirmalakhandan
Keyword(s):  
Activated Sludge ◽  
Continuous Flow ◽  
Growth Conditions ◽  
Aeration Tank ◽  
Biomass Growth ◽  
Waste Sludge ◽  
Process Configuration ◽  
Activated Sludge System ◽  
Expensive Problems ◽  
Cryptic Growth

The ultimate disposal of biosolids has been and continues to be one of the most expensive problems faced by wastewater utilities. The objective of this research is to develop a process configuration for reducing the waste sludge generation in an activated sludge plant by promoting cryptic growth conditions (i.e., biomass growth on intracellular products). For this purpose, excess biosolids from a continuous flow activated sludge system were solubilized using ozone as the cell lysis agent, and then returned to the aeration tank. It is hypothesized that growth under such cryptic conditions will result in low net microbial yields, and hence, minimal net solids wastage. The results of these preliminary studies indicate that the proposed process configuration has the potential to reduce the waste sludge production by 40% to 60%.

Activated sludge population dynamics

1994 ◽  
Vol 30 (11) ◽  
pp. 159-169 ◽  
Author(s):  
Jiri Wanner
Keyword(s):  
Population Dynamics ◽  
Activated Sludge ◽  
Organic Pollution ◽  
Paper Briefly ◽  
Microbial Composition ◽  
Selection Mechanisms ◽  
Sludge Settling

The paper briefly surveys topics covered by the IAWQ Specialist Group on Activated Sludge Population Dynamics. The activated sludge population dynamics has been formulated as a branch of water science and technology concerned with phenomena governing the relationships between activated sludge microorganisms and their functions. The characterization of organic pollution fractions in wastewaters according to their rate of biodegradation has been discussed and the role of wastewater as an inoculum stressed. The characterization of activated sludge biomass has been evaluated from two viewpoints: grouping according to metabolic abilities and identification and classification of activated sludge microorganisms. The basic selection mechanisms influencing the microbial composition of activated sludge have been described. The problems with activated sludge settling and thickening properties have been mentioned as a typical example of applied population dynamics research.

scholarly journals ACTUALITY OF APPLICATION OF BIOGAS INSTALLATIONS IN RUSSIA AND ABROAD

2017 ◽  
Vol 12 (2) ◽  
pp. 71-74
Author(s):  
Булат Зиганшин ◽  
Bulat Ziganshin ◽  
Ильназ Кашапов ◽  
Ilnaz Kashapov ◽  
Ильнур Гайфуллин ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Power Plants ◽  
Biogas Production ◽  
Operating Experience ◽  
Farm Animals ◽  
National Program ◽  
Urban Wastewater ◽  
The World ◽  
Short Time ◽  
Made In

The first scientific developments in the field of biogas technologies were made in Russia more than 70 years ago. Since the 50th years one of the main directions was the anaerobic processing of activated sludge and sediments of urban wastewater. This method attracted attention in connection with the idea of obtaining biogas mainly from the manure of farm animals. Thanks to this in the middle of 50th years a number of pilot plants for biogas production were built in Zaporozhia, Belorussian, Georgian, Moldavian branches of All-Russian Institute of Agriculture Electrification, and also in Ekaterinburg. However, the operating experience of these installations was insignificant - one - two seasons. The problem of obtaining and using biogas is given great attention abroad. In a short time, in many countries around the world a whole industry for the production of biogas has emerged. The leader in the development of biogas industry is China. Since the middle of 1970, the National Program for the production of biogas from livestock wastes has been operating in this country. Currently, there are 10 million farm bioreactors. In addition, 40 000 biogas stations, 24 000 biogas treatment plants operate in China, which provides operation of 190 power plants.

Sign in / Sign up

Export Citation Format

Share Document