The Effect of Metallic and Ionic Species on the Performance of a Biological Effluent Treatment System

1977 ◽  
Vol 12 (1) ◽  
pp. 191-212
Author(s):  
B. Volesky ◽  
Q. Samak ◽  
P. Waller
Keyword(s):  
Activated Sludge ◽  
Inorganic Ions ◽  
Industrial Effluents ◽  
Original Data ◽  
Ionic Species ◽  
Threshold Concentration ◽  
Effluent Treatment ◽  
Organic Load ◽  
Metallic Ions ◽  
Activated Sludge Systems

Abstract Review of the available results appearing in the recent literature is presented focusing particularly upon the effects of metallic ions such as Cr, Cu, Zn, Cd, Hg, V, Zn, Ni and Co. Some original data involving the effects of Na are presented and discussed. Development of parameters used in evaluating the influence of toxic or inhibitory species on the mixed microbial population of an activated sludge system is of crucial importance and different techniques employed such as BOD-COD-TOC-removal rates, Oxygen Uptake Rate, and others are discussed, showing relative inadequacy of currently applied assays. From the data available, certain trends can be discerned. There is a definite threshold concentration for each metallic ion, depending on the organic load of the feed. In the order of increasing toxicity to activated sludge systems reflected in lower BOD removals the following metals have been listed as inhibiting factors at concentrations starting from 1 ppm applied on a continuous basis: hexavalent chromium, cobalt, zinc, cadmium, trivalent chromium, copper and nickel. Metals in combination have not been reported to exhibit any significantly different effects as compared to those observed with individually introduced metallic ions. Tolerance of some activated sludge systems to shock loadings by various inorganic ions and metals is reviewed. The conclusions are of particular importance for estimating the performance of biox systems handling industrial effluents which are likely to contain toxic components of inorganic or metallic nature.

Oxygen transfer in activated sludge – new insights and potentials for cost saving

2011 ◽  
Vol 63 (12) ◽  
pp. 3034-3038 ◽  
Author(s):  
J. Henkel ◽  
P. Cornel ◽  
M. Wagner
Keyword(s):  
Activated Sludge ◽  
Nutrient Removal ◽  
Oxygen Transfer ◽  
Transfer Rate ◽  
Oxygen Transfer Rate ◽  
Organic Load ◽  
Current Opinion ◽  
Conventional Activated Sludge ◽  
Current State ◽  
Activated Sludge Systems

The α-factor has the greatest impact on the calculation of the required standard oxygen transfer rate (SOTR) in activated sludge systems equipped with submerged aeration systems. Knowing the dependencies of the α-factor leads to a better design of the aeration devices and, consequently, to a more efficient use of aeration energy. Applying the current state of knowledge about oxygen transfer leads to the conclusion that, in contrast to current opinion, simultaneous aerobic stabilization requires the same SOTR as conventional activated sludge systems with advanced nutrient removal, even though a higher organic load is degraded.

Paper mill effluent treatment using biofiltration

1994 ◽  
Vol 29 (10-11) ◽  
pp. 217-222 ◽  
Author(s):  
J. M. Rovel ◽  
J. P. Trudel ◽  
P. Lavallée ◽  
I. Schroeter
Keyword(s):  
North America ◽  
Flow Rate ◽  
Industrial Effluents ◽  
Paper Mill ◽  
Pulp And Paper ◽  
Effluent Treatment ◽  
Paper Mills ◽  
Paper Mill Effluent ◽  
Sudden Load ◽  
Activated Sludge Systems

The results achieved on industrial effluents from four different paper mills, ranging from highly diluted effluents from units for the production of fine papers using bleached cellulose, to much more concentrated effluents from an integrated pulp and paper plant, show the potential and advantages of the Biofor process. Implemented as a complement to or replacement for activated sludge systems, the BioforR process, which dispenses with the clarification step and offers excellent resistance to sudden load and flow rate variations, is particularly well suited to the needs of this industry. This explains the rapid success already achieved in Europe and expected soon in North America.

scholarly journals Treatment of wastewater from the dairy industry with Moringa Oleífera using two different methods

2021 ◽  
Vol 10 (7) ◽  
pp. e21710716514
Author(s):  
Alana Lopes Junho ◽  
Ivan Felipe Silva dos Santos ◽  
Athos Moisés Lopes Silva ◽  
Regina Mambeli Barros ◽  
Danielle Ornaghi Sant'Anna ◽  
...  
Keyword(s):  
Moringa Oleifera ◽  
Saline Solution ◽  
Dairy Industry ◽  
Industrial Effluents ◽  
Effluent Treatment ◽  
Organic Load ◽  
Dairy Foods ◽  
Jar Test ◽  
Crude Sample ◽  
Natural Coagulants

Dairy foods represent a large market, grossing more than $125 billion per year worldwide. Dairy effluent has high organic load and therefore must be treated before disposing in the water bodies. Natural coagulants represent a good option for effluent treatment, among which is the Moringa Oleífera (MO) seed. In this sense, the present work experimentally evaluates the effluent treatment efficiency of the dairy industrial effluents using coagulants based on the MO seed, also discussing environmental and economic potentialities of seed planting. Evaluation was carried out by use of the MO seed both directly (comminuted) and in saline solution by Jar Test essay. The COD clarification and removal efficiency of the crude sample was evaluated for different initial turbidity and coagulant volume scenarios. The results showed a high turbidity reduction efficiency (between 97 and 99%) in most of the tests by the direct use of MO seeds. The cropped area required for this application in a dairy industry with processing of 10 m³ of milk per day was 1775 m². The use of MO seed in saline solution did not achieve the same efficiency, indicating the need to optimize the test parameters. The results might to base more extensive discussions of potentialities and limitations of the use of MO seed as a potential coagulant.

scholarly journals Treatment efficiency and sludge characteristics in conventional and suspended PVA gel beads activated sludge treating phenol containing wastewater

2018 ◽  
Vol 20 (1) ◽  
pp. 42-48 ◽  
Keyword(s):  
Activated Sludge ◽  
Removal Rate ◽  
Synthetic Wastewater ◽  
Organic Load ◽  
Phenol Removal ◽  
Treatment Efficiency ◽  
Good Efficiency ◽  
Gel Beads ◽  
Pva Gel ◽  
Activated Sludge Systems

Protozoa play a significant role in activated sludge systems, since they graze on dispersed bacteria, supporting a healthy food web in the activated sludge artificial ecosystem. However, operational parameters and influent properties are the most important factors affecting the composition of activated sludge microfauna. The objective of this study was the assessment of the treatment efficiency and the protozoan populations in activated sludge systems with and without the addition of polyvinyl alcohol (PVA) gel beads while treating wastewater in the presence of phenol. Six activated sludge reactors - 3 of them supplied with PVA gel beads –were used for the treatment of synthetic wastewater influent containing phenol at concentrations up to 10 mg/L. During the treatment of synthetic wastewater, dominance of the sessile species was observed mainly in the reactors supplied with PVA beads. Physicochemical analyses of the effluent indicated good efficiency of reactors supplied with PVA beads in removing nutrients and organic load. Introduction of phenol in the influent at a concentration of 5 mg/L did not affect significantly the operation of the reactors and the composition and abundance of activated sludge microfauna, while a high phenol removal rate was observed. The increase of influent phenol concentration to 10 mg/L resulted to the formation of foam on the surface of the reactors and the presence of Zoogleasp, while an increase was observed in the abundance of crawling species in activated sludge and PVA supplied reactors respectively.

Variation in Sludge Settleability with Temperature

1980 ◽  
Vol 15 (1) ◽  
pp. 73-82 ◽  
Author(s):  
J.G. Henry ◽  
E.E. Salenieks
Keyword(s):  
Activated Sludge ◽  
Effect Of Temperature ◽  
Organic Load ◽  
Limiting Factor ◽  
Appreciable Effect ◽  
Loading Rates ◽  
Bench Scale ◽  
Filamentous Bulking ◽  
Filamentous Microorganisms ◽  
Sludge Settleability

Abstract This study examined the effect of temperature on the settleabi1ity of activated sludge at various organic loading rates. Five completely mixed, bench-scale, activated sludge plants, operating under similar conditions at 5, 10 and 19°C, were continuously fed diluted, settled sewage supplemented with carbohydrate (sucrose). Hydraulic loading rates, MLSS and pH were maintained at constant levels during the experiments to eliminate these factors are variables. Dissolved oxygen was kept in excess of 3 mg/1 so that it would not be a limiting factor. Sludge Volume Indices (SVI ) and zone settling velocities were used to indicate changes in sludge settleability. Microscopic examination of the activated sludge indicated significant differences in the morphological features of filamentous microorganisms present at the two temperature extremes. At 19°C, the predominant forms were characterized by long curving trichomes, occasionally falsely branching, containing short cylindrical cells. At 5 °C, much smaller straight filaments, composed of long, narrow, rod-shaped cells appeared to be the principal microorganisms responsible for bulking. Various other filamentous forms were always present at each of the temperatures studied. Stirred sludge settling tests of moderately bulking sludges generally exhibited much higher settling velocities and lower SVI's than unstirred bulking samples. However, extremely filamentous bulking sludge exhibited comparable stirred and unstirred settling velocity and SVI values. The standard SVI test was found to be an inadequate indicator of the extent of bulking when trying to correlate the SVI failures from bench-scale performance with the results from continuous units. Lower temperature had no appreciable effect on COD removal efficiency as long as bulking did not cause a loss of solids in the effluent. However, results suggested that less than half the organic load could be accepted at 5°C, that could be handled at 19°C, before filamentous bulking occurred. A plot of loading versus temperature for various SVI's provided a visual indication of the safe loading limit below which bulking was unlikely to occur. The study clearly demonstrated that temperature can have a significant effect on sludge settleability.

On the Problem of “Two-Phase” Activated Sludge

1991 ◽  
Vol 24 (7) ◽  
pp. 59-64 ◽  
Author(s):  
R. W. Szetela
Keyword(s):  
Activated Sludge ◽  
Single Phase ◽  
Phase System ◽  
Two Phase ◽  
Wastewater Treatment Process ◽  
Sludge Stabilization ◽  
Technological Advantage ◽  
In Series ◽  
State Models ◽  
Activated Sludge Systems

Steady-state models are presented to describe the wastewater treatment process in two activated sludge systems. One of these makes use of a single complete-mix reactor; the other one involves two complete-mix reactors arranged in series. The in-series system is equivalent to what is known as the “two-phase” activated sludge, a concept which is now being launched throughout Poland in conjunction with the PROMLECZ technology under implementation. Analysis of the mathematical models has revealed the following: (1) treatment efficiency, excess sludge production, energy consumption, and the degree of sludge stabilization are identical in the two systems; (2) there exists a technological equivalence of “two-phase” sludge with “single-phase” sludge; (3) the “two-phase” system has no technological advantage over the “single-phase” system.

The Use of Anoxic Selectors for the Control of Low F/M Activated Sludge Bulking

1989 ◽  
Vol 21 (6-7) ◽  
pp. 609-619 ◽  
Author(s):  
Y.-J. Shao ◽  
David Jenkins
Keyword(s):  
Organic Matter ◽  
Activated Sludge ◽  
Pilot Plant ◽  
Detention Time ◽  
Substrate Removal ◽  
Batch System ◽  
Sludge Bulking ◽  
N Removal ◽  
Soluble Substrate ◽  
Activated Sludge Systems

Laboratory and pilot plant experiments on anoxic selector activated sludge systems were conducted on two wastewaters in some cases supplemented with nitrate, acetate or glucose. To prevent bulking sufficient anoxic selector detention time and nitrate levels must be available to reduce selector effluent soluble COD to below 100 mg/l and to reduce readily metabolizable organic matter to virtually zero (< 1 mg/l). Soluble COD/NO3-N removal stoichiometry is in the range 6.0-6.7. Selector systems have elevated soluble substrate removal and denitrification rates compared to CSTR systems. These rates are not affected greatly by temperature (20-25°C) for CSTR sludges but are for selector sludges. Upon exhaustion of nitrate in a selector soluble COD leaks out of the activated sludge in significant amounts. Thiothrix sp. and type 021N denitrify only to NO2 and at much slower rates than Zoogloearamigera does to N2. A sequencing batch system provides an optimistic estimate of the SVI that can be obtained by an anoxic selector system.

The Efficiency of a Biological Activated Sludge Effluent Treatment Plant with Extended Aeration

1988 ◽  
Vol 20 (1) ◽  
pp. 65-72 ◽  
Author(s):  
Rurik Skogman ◽  
Reino Lammi
Keyword(s):  
Activated Sludge ◽  
Suspended Solids ◽  
Treatment Plant ◽  
Forest Products ◽  
Effluent Treatment ◽  
Chlorinated Phenols ◽  
Forest Products Industry ◽  
Effluent Treatment Plant ◽  
Closed Systems ◽  
Treating Effluent

The requirements imposed on the Finnish forest products industry by the water authorities have focused on the reduction of BOD and suspended solids in the wastewaters. The industry has tried to comply with these requirements, first through internal measures such as process changes and closed systems. When these have not been sufficient, external treatment has been resorted to. The Wilh. Schauman Company in Jakobstad has chosen activated sludge with extended aeration from among the available methods for treating effluent. The plant has operated since the beginning of 1986 with extremely good results. In addition to the reduction of BOD and suspended solids, there has been a marked decrease of chlorinated phenols. Chlorinated substances with higher molecular weight are also removed during the process.

Quantification of the kinetic differences between communities isolated from completely mixed activated sludge systems operated with or without a selector using a novel respirometric method

1994 ◽  
Vol 30 (11) ◽  
pp. 255-261 ◽  
Author(s):  
Barth F. Smets ◽  
Timothy G. Ellis ◽  
Stephanie Brau ◽  
Richard W. Sanders ◽  
C. P. Leslie Grady
Keyword(s):  
Oxygen Consumption ◽  
Activated Sludge ◽  
Physiological Changes ◽  
Biodegradation Kinetics ◽  
Substrate Removal ◽  
Biomass Yields ◽  
Selection For ◽  
Single Oxygen ◽  
Activated Sludge Systems

This study quantified the kinetic differences in microbial communities isolated from completely mixed activated sludge (CMAS) systems that were operated either with or without an aerobic selector preceding the main reactor. A new respirometric method was employed that allowed the determination of biodegradation kinetics from single oxygen consumption curves, thereby minimizing physiological changes to the examined communities during the assay. Results indicated that increased values for Ks and μmax for acetate, phenol, and 4-chlorophenol degradation were measured in the CMAS system operated with a selector. The biomass yields on acetate, phenol, and 4-chlorophenol were very similar in both systems. These findings indicate that the operation of CMAS systems with aerobic selectors may result in the selection for degrading populations with higher Ks and μmax values for both biogenic and xenobiotic organic compounds, and that substrate storage in the selector only partially contributes to increased substrate removal rates.

Sign in / Sign up

Export Citation Format

Share Document