Removal of organics from wastewater using a novel biological hybrid system

2001 ◽  
Vol 43 (1) ◽  
pp. 321-326 ◽  
Author(s):  
H. A. Al-Sharekh ◽  
M. F. Hamoda
Keyword(s):  
Activated Sludge ◽  
Hybrid System ◽  
Treatment Plant ◽  
Minor Effect ◽  
Loading Rates ◽  
Innovative System ◽  
The Mean ◽  
Percentage Removal ◽  
Removal Efficiencies ◽  
A Minor

This paper summarizes the results obtained using the hybrid aerated submerged fixed-film (HASFF) process. HASFF is an innovative system comprising a four-compartment reactor having an array of fixed ceramic plates maintained under diffused aeration to support attached biomass, with activated sludge recycle to promote suspended growth in the reactor. Wastewater from a municipal treatment plant was fed to the reactor and its activated sludge was used for recycling in the hybrid system. Four pilot units were operated in the plant at various hydraulic retention times, HRTs (2, 4, 6 and 8 h), using primary-settled wastewater under organic loading rates up to 0.7 g BOD/gMLTVS · d. Data obtained showed that the overall BOD percentage removal efficiencies were consistently above 94.0% at all HRTs including the 2 hours while the COD percentage removal efficiencies ranged between 65.7–76%. The effluent's mean filtered BOD concentration ranged between 4.5–7.5 mg/l whereas the mean filtered COD concentration ranged between 70.0–89.6 mg/l. Increasing the hydraulic loading rate by four-folds from 0.08 to 0.32 m3/m2 · d had a minor effect on the unit's BOD and COD percentage removal efficiencies indicating a robust biological process that is resilient to hydraulic shock loads, thereby offering a viable upgrading option.

Behaviour of Alkylphenol Polyethoxylate Surfactants and of Nitrilotriacetate in Sewage Treatment

1987 ◽  
Vol 19 (3-4) ◽  
pp. 449-460 ◽  
Author(s):  
W. Giger ◽  
M. Ahel ◽  
M. Koch ◽  
H. U. Laubscher ◽  
C. Schaffner ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Sewage Treatment ◽  
Operating Conditions ◽  
Municipal Sewage ◽  
Sludge Treatment ◽  
Loading Rates ◽  
Treatment Conditions ◽  
Physico Chemical ◽  
Treated Sewage ◽  
Removal Efficiencies

Effluents and sludges from several municipal sewage treatment plants in Switzerland were analyzed for nonylphenol polyethoxylates (NPnEO, n=3-20), nonylphenol mono- and diethoxylate (NPlEO, NP2EO), corresponding nonylphenoxy carboxylic acids (NP1EC, NP2EC) and nonylphenol (NP). These chemicals derive from nonionic surfactants of the NPnEO-type, and specific analitical techniques were used to study their behaviour during mechanical-biological sewage and subsequent sludge treatment. The parent NPnEO-surfactants, with concentrations in raw and mechanically treated sewage from 400-2200 mg/m3, were relatively efficiently removed by the activated sludge treatment. The abundances of the different metabolites varied depending on treatment conditions. The refractory nature of NPl/2EO, NP and NPl/2EC was recognized. Both biotransformations and physico-chemical processes determine the behaviour and fate of nonylphenolic substances in sewage treatment. Nitrilotriacetate (NTA) was found in primary effluents at concentrations between 430 and 1390 mg/m3. The various treatment plants showed different removal efficiencies for NTA depending on the operating conditions. Activated sludge treatment with low sludge loading rates and nitrifying conditions removed NTA with efficiencies between 95 and 99%. High sludge loading caused a decrease in NTA removal efficiencies from 70% to 39%.

Simultaneous activated sludge wastewater treatment and odour control

2001 ◽  
Vol 44 (9) ◽  
pp. 189-196 ◽  
Author(s):  
P. Hardy ◽  
J.E. Burgess ◽  
S. Morton ◽  
R.M. Stuetz
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Treatment Process ◽  
Treatment Plant ◽  
Process Performance ◽  
Wastewater Treatment Process ◽  
Wet Scrubbing ◽  
Odour Control ◽  
Removal Efficiencies ◽  
Performance Results

Lab-scale tests were used to determine the amount of H2S that can be treated using a range of different activated sludges. Static vessels were used to study the effects of different H2S concentrations (5, 25, 50 and 75 ppm). The data indicated that odour control may be carried out using certain types of sludge, but sludge type, e.g. carbonaceous, nitrifying, with or without coagulant, affects removal efficiency. The presence of the biomass resulted in greater H2S removal than the use of wet scrubbing and the adverse effects on mixed liquor were negligible. A pilot plant was used to study the removal efficiencies of activated sludge diffusion using a typical wastewater treatment plant H2S concentration and investigated the effects that the diffusion of H2S had on the process performance. Results indicated that the levels of H2S produced by other unit processes on a wastewater treatment site (approximately 5 ppm) can be treated using activated sludge diffusion without compromising the performance of the wastewater treatment process. The only effects on the activated sludge plant observed were: (1) nitrification was interrupted briefly as H2S diffusion commenced and (2) the species' diversity in the sludge decreased.

scholarly journals Coke oven wastewater treatment by two activated sludge systems

2013 ◽  
Vol 8 (1) ◽  
pp. 16-22
Keyword(s):  
Organic Matter ◽  
Wastewater Treatment ◽  
Activated Sludge ◽  
Nutrient Removal ◽  
Municipal Wastewater ◽  
Treatment Plant ◽  
Coke Oven ◽  
Synthetic Wastewater ◽  
Removal Efficiencies ◽  
Activated Sludge Systems

In this study two bench scale activated sludge systems were used, a CSTR and an SBR for the treatment of coke – oven wastewater. Both reactors were inoculated with activated sludge from a municipal wastewater treatment plant. At the first stages of operation, reactors were feed by a mixture of municipal wastewater and synthetic wastewater. Full acclimatization of the microorganisms to synthetic wastewater was achieved in 60 days. The operation of the reactors was divided into three distinct periods. The first period was characterized by the treatment of high organic but non-toxic synthetic wastewater. During this period COD and BOD5 removal efficiencies reached 95 and 98% respectively, in both reactors. Nutrient removal was better in the SBR reactor rather than in the CSTR. In the second period phenol was added in concentrations up to 300 mg l-1. Degradation of phenol started about the 20th day after its introduction to the reactors. In this period no effects of phenol to nutrient removal were observed, whereas the removal efficiency of organic matter in both reactors was slightly decreased. During the third period phenol concentrations of the influent were gradually increased to 1000 mg l-1, while cyanide and thiocyanite were added to the influent composition to concentrations reaching concentrations of 20 and 250 mg l-1 respectively. The composition of the influent of this period was a full assimilation of coke oven wastewater. Introduction of increased phenol concentrations along with cyanide compounds initiated irreversible effects on the activated sludge microfauna of the CSTR causing inherent problems to the treatment process, while SBR showed greater capacity to withstand and degrade toxic compounds. The beginning of this period was characterized by decreased settleability of the suspended solids as well as decrease of organic matter and nutrient removal efficiencies. Monitoring of the effluent characteristics during this period reported over 90% for organic load, 85% of nutrient removal and over 90% of phenol and cyanide removal in SBR, while the removal efficiencies for the CSTR were 75, 65 and 80% respectively.

A Comparative Study of Biopolymers from a Conventional and an Advanced Activated Sludge Treatment Plant

1994 ◽  
Vol 29 (7) ◽  
pp. 137-141 ◽  
Author(s):  
B. Frølund ◽  
K. Keiding ◽  
P. H. Nielsen
Keyword(s):  
Activated Sludge ◽  
Treatment Plant ◽  
Ion Exchange Resin ◽  
Size Exclusion ◽  
Chemical Compositions ◽  
Sludge Treatment ◽  
Traditional Treatment ◽  
Hydrophobic Compounds ◽  
Exclusion Chromatography ◽  
A Minor

Biopolymer characteristics from a traditional and an advanced activated sludge treatment plant performing biological N and P removal were compared. The biopolymers were extracted using an ion exchange resin (DOWEX in Na-form). Differences between chemical compositions of the total sludges were observed by measuring protein, polysaccharide and uronic acids whereas differences in the same compounds were not found in the extracted biopolymers. High Pressure Size Exclusion Chromatography was performed on the two biopolymer matrixes and differences were found in the biopolymer matrixes. Biopolymers from the advanced treatment plant contained two fractions of large and hydrophobic compounds which contributed to a major fraction of the chromatogram area. These peaks could only to a minor extent be found in the extracted biopolymers from the traditional treatment plant.

Evaluation of Purification Efficiency of Activated Sludge Treatment Plants for Pulp and Paper Industry Wastewaters in Finland

1990 ◽  
Vol 22 (9) ◽  
pp. 199-206
Author(s):  
J. Junna ◽  
J. Rintala
Keyword(s):  
Activated Sludge ◽  
Suspended Solids ◽  
Paper Industry ◽  
Pulp And Paper Industry ◽  
Pulp And Paper ◽  
Pulp Mills ◽  
Sludge Treatment ◽  
Actual Performance ◽  
Loading Rates ◽  
Removal Efficiencies

Since 1984, when the first activated sludge treatment plant (ASTP) was built to treat pulp and paper industry wastewaters in Finland, twenty more plants have been introduced by 1989. An evaluation was undertaken to find out the actual performance of the ASTPs in BOD7, CODc r and phosphorus removal. The evaluation included all the 12 ASTPs in operation in the pulp and paper industry at the beginning of 1987. The highest average BOD7 removals were about 90 % at pulp mills as well as paper and board mills. CODc r removal was generally higher at paper and board mills (about 40-70 %) than at pulp mills (about 25-55 %). Phosphorus was added to wastewater in most plants. In some ASTPs, phosphorus concentrations were lowered by 20-40 % compared with wastewater from the mill. In some plants phosphorus load on the recipient was higher than the load coming from the mill. In treated wastewater, correlations between suspended solids and BOD7, CODc r, phosphorus and nitrogen were significant in most plants. This indicated that low removal efficiencies resulted from poor suspended solids removal in the secondary clarification. Volumetric and sludge CODc r loading rates could not explain removal efficiencies when all plants were included in the comparison. In plants treating chemical pulping effluents, higher removal efficiencies were normally achieved with lower loading rates. When the plants were studied separately, the influence of loading rate was generally significant.

scholarly journals Arcobacter cryaerophilusand thermophilic campylobacters in a sewage treatment plant in Italy: two secondary treatments compared

1993 ◽  
Vol 110 (3) ◽  
pp. 633-639 ◽  
Author(s):  
S Stampi ◽  
O Varoli ◽  
F Zanetti ◽  
G De Luca
Keyword(s):  
Activated Sludge ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Most Probable Number ◽  
Tertiary Treatment ◽  
Probable Number ◽  
Urban Sewage ◽  
Thermophilic Campylobacter ◽  
The Mean

SUMMARYMicroaerophilic organisms were monitored in sewage effluent undergoing two secondary treatments: air and oxygen-activated sludge. The mean numbers ofArcobacter cryaerophilusand thermophilic campylobacters detected in incoming sewage were 5639/100 ml and 1720/100 ml respectively.Secondary treatment in air tanks reduced the population ofA. cryaerophilusby 97.1% and of thermophilic campylobacters by 99.08%, whereas treatment in oxygen tanks reduced the bacteria 97.8% and 99.63% respectively, showing that oxygen-activated sludge treatment was more effective. Subsequent tertiary treatment with 2 p.p.m. chlorine dioxide evidenced the removal ofA. cryaerophilusto 99.9% and eliminated thermophilic campylobacters.Campylobacter jejuniandC. coliconstituted 54.1% and 45.9% of 74 thermophilic campylobacter strains isolated. In air-activated sludge effluentC. jejuniwas found more often, thus appearing more sensitive to oxygen.The most probable number assay used for detection of campylobacters, blood medium for enrichment and blood-free medium for plating, also appeared to be fit forA. cryaerophilus, the high density of which in urban sewage may be due to inflows from slaughterhouses.

scholarly journals Ammonia and Phosphorous removal in municipal wastewater treatment plant with extended aeration.

2013 ◽  
Vol 1 (1) ◽  
pp. 47-53
Keyword(s):  
Activated Sludge ◽  
Municipal Wastewater ◽  
Combined Treatment ◽  
Cell Formation ◽  
Treatment Plant ◽  
Mean Value ◽  
Aeration Tank ◽  
Municipal Wastewater Treatment ◽  
Denitrification Kinetics ◽  
The Mean

Samples were taken from Metamorphosis/Attica combined treatment plant for municipal wastewater and septage, which treats about 12000 m3 d-1 of municipal wastewater and 8000 m3 d-1 of septage, and analyzed for solids, COD, ammonia, nitrate, orthophosphate, polyphosphate and total phosphorus. Ammonia is almost completely eliminated within the plant. Orthophosphates show a removal of about 28%, while total phosphorus is removed by about 15%. The mean value of the ratio (phosphorus eliminated)/(COD eliminated) in mg g-1 is 8. Assuming suspended-growth nitrification and denitrification kinetics as proposed in literature, the percentage of nitrifiers in the activated sludge population is estimated at 1.1%. Assuming that phosphorus removal in the aeration tank is proportional to cell formation, which in turn is proportional to substrate elimination, the phosphorus content of the activated sludge is estimated at 0.031 gP (gVSS)-1.

scholarly journals REMOVAL OF ORGANIC MATTERS FROM PIGGERY WASTEWATER IN ANAEROBIC MOVING BED BIOFILM REACTOR (MBBR)

2020 ◽  
Vol 58 (3A) ◽  
pp. 211
Author(s):  
Quan Truong Nguyen ◽  
Quan Truong Nguyen ◽  
Ha Thi Nguyen
Keyword(s):  
Treatment Plant ◽  
Biofilm Reactor ◽  
Cod Removal ◽  
Organic Loading ◽  
Moving Bed Biofilm Reactor ◽  
Piggery Wastewater ◽  
Organic Matters ◽  
Moving Bed ◽  
Loading Rates ◽  
Removal Efficiencies

The objective of this study is to investigate the performance of Anaerobic Moving Bed Biofilm Reactor (MBBR) on the removal of organic matters (using COD and TSS values) in piggery wastewater using two kinds of carrier: Polyurethane (PU) and Polyethylene (PE) - Different organic loading rates (OLRs) varying from 4 to 10 gCOD/l/day with controlled temperature 37±2oC, pH 7.0-7.5 were investigated. The seeded sludge was collected at the anaerobic tank of the wastewater treatment plant of the Sabeco Beer Manufacturing Plant (Nam Tu Liem district, Hanoi) and grown in the MBBR for 15 days. For porous PU material, the COD and TSS removal efficiencies achieved 69.7 and 67.3% and 54.9 and 65.5% at OLR 4 and 6 gCOD/l/day, respectively.  Whereas for wheel shape PE material, it was found that the COD removal efficiencies were slightly higher with OLR of 6  gCOD/l/day (71%%), even with higher OLR at 10 gCOD/l.day, the COD removal efficiency didn‘t seem to significantly increase (73.3 %). For TSS removal, in comparison between PU and PE, the later found slightly better with the same OLRs of 4 and 6 gCOD/l/day, reaching 63.2 and 67 %, respectively. However, TSS removal efficiencies were found to be higher with PE carrier at higher OLR, reaching 72% at 10 gCOD/l/day.

Treatment of bleaching effluent in sequential activated sludge and nitrification systems

1999 ◽  
Vol 40 (1) ◽  
pp. 269-274
Author(s):  
U. Altınbaş ◽  
V. Eroǧlu ◽  
İ. Öztürk
Keyword(s):  
Activated Sludge ◽  
Removal Efficiency ◽  
Degradation Mechanisms ◽  
Organic Loading ◽  
Loading Rates ◽  
Toc Removal ◽  
Activated Sludge Reactor ◽  
Removal Efficiencies

Dechlorination and degradation mechanisms of bleaching effluent were studied in a sequential activated sludge and nitrification reactor. Effect of bleaching effluent on dechlorination performances was examined at various organic loading rates in the system. Released inorganic chlorine (ICl) was increased from 4.5 to 8.5 mg/l in the first stage activated sludge reactor while it was decreased from 10 to 2.5 mg/l in the subsequent nitrification reactor. Removal efficiencies of AOX were found as 15-33% and 5-25% in the activated sludge and the nitrification reactor respectively. TOC removal efficiencies achieved were 67-85% in the activated sludge reactor. The removal efficiency of NH4 achieved 94-98% in the nitrification reactor.

Influence of Testing Variables on the Concrete Compressive Strength

1975 ◽  
Vol 2 (4) ◽  
pp. 606-611
Author(s):  
T. Dale Rokosh ◽  
K. W. Nasser
Keyword(s):  
Compressive Strength ◽  
Compression Test ◽  
Minor Effect ◽  
Concrete Compressive Strength ◽  
Testing Laboratories ◽  
Concrete Mix ◽  
Commercial Testing ◽  
The Mean ◽  
A Minor ◽  
Good Rating

This study assessed the significance of testing variables due to casting, curing, and breaking standard concrete compression test cylinders in three Saskatoon, Saskatchewan commercial testing laboratories. Analysis of the results indicated that these variables have a minor effect on the results when the laboratories have a 'good' rating. Nonuniformity of the concrete mix itself seemed to have the greatest influence on the within-test variation and caused the mean compressive strength in each laboratory to differ by ±4% of the overall mean strength of the mix.

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