Sludge accumulation in polishing ponds treating anaerobically digested wastewater

2002 ◽  
Vol 45 (1) ◽  
pp. 75-81 ◽  
Author(s):  
P. Cavalcanti ◽  
A. van Haandel ◽  
G. Lettinga
Keyword(s):  
Pilot Scale ◽  
Important Conclusion ◽  
Solids Concentration ◽  
Volatile Solids ◽  
Useful Life ◽  
One Year ◽  
Uasb Reactors ◽  
Very High ◽  
Sludge Accumulation

When ponds are used for wastewater treatment, settleable solids will form a steadily growing bottom sludge layer, which reduces their effective volume. Eventually this sludge must be removed to ensure that the pond maintains the required retention time to keep performing properly. The settleable solids may either be present in the influent or they are formed during the treatment as a result of algal flocculation. An experimental investigation was carried out to evaluate bottom sludge accumulation in a polishing pond used for treatment of UASB effluent. The mass and composition of the bottom sludge formed in a polishing pond was evaluated after the pilot scale pond had been in operation for 1 year and about 60 m3 of digested wastewater had been treated per m3 of pond. The bottom sludge mass represented a solids accumulation of 70 g per m3 of digested wastewater. About half of these solids were the result of settling of influent solids in the first part of the pond, while the other half was attributable to settling of algae, formed in the pond. It is concluded that the bottom sludge growth in a polishing pond is so low, that desludging during the useful life span of the pond will most likely not be necessary. This leads to the important conclusion that excess sludge discharge from UASB reactors (a major factor in operational costs) may be omitted, if a polishing pond is used for post-treatment. The bottom sludge had a high volatile solids concentration (58%) and the macronutrient fractions were also high (3.9% N and 1.1% P of the TSS mass). The bottom sludge was stable and could be dried directly without problems. The hygienic quality of the bottom sludge was very poor: about half the influent helminth eggs during one year of operation were found in the bottom sludge and the faecal coliform concentration was very high.

Experimental and modeling evaluation of upward and downward velocities in the coaxial flotation column

2001 ◽  
Vol 43 (8) ◽  
pp. 195-201 ◽  
Author(s):  
K. Park ◽  
J.-M. Cho ◽  
J. Oh ◽  
K. Chung
Keyword(s):  
Removal Efficiency ◽  
Pilot Scale ◽  
Coaxial Cylinder ◽  
Treated Water ◽  
Flotation Column ◽  
Solids Loading ◽  
Solids Concentration ◽  
Upward Velocity ◽  
Solids Removal

This study was conducted to show the influence of upward velocity in the inner column and downward velocity in the outer column of the coaxial cylinder-type flotation column on the solids removal efficiency, solids concentration in the treated water, and so on. The SIMPLE (Semi-Implicit Method for Pressure Linked Equation) solution was applied to the coaxial flotation column to simulate the velocity vectors of the elements of water flowing in the column. The effects of solids loading and residence time in the agglomerate separation zone on the solids removal efficiency were also tested. In the pilot scale coaxial DAF column experiments with solids concentration of 1,000–2,000 mg of SS per liter and solids loading less than 350 kg/m2/day, approximately 90% of the solids removal efficiencies were obtained using the upward velocity of up to 110 cm/min in the contact zone of the inner column and the downward velocity of up to 30 cm/min in the outer column. In the simulation, similar results were observed as in the experiments. The solids loading in the excess of 350 kg/m2/day caused the instability of the sludge float layer and aggravated the quality of the treated water.

A pilot-scale evaluation of aerobic–anoxic sludge digestion

1990 ◽  
Vol 17 (1) ◽  
pp. 68-78 ◽  
Author(s):  
C. C. Peddie ◽  
D. S. Mavinic
Keyword(s):  
Pilot Scale ◽  
Intermittent Aeration ◽  
Scale Evaluation ◽  
Digestion Process ◽  
Batch Tests ◽  
Sludge Digestion ◽  
Volatile Solids ◽  
Mode Of Operation ◽  
Experimental Runs

A pilot-scale (300 L) evaluation of waste-activated sludge digestion by a cyclical aerobic–anoxic mode of operation was undertaken at ambient liquid temperatures (14–17 °C). Three experimental runs were conducted over a 2-year period. The first run compared the aerobic–anoxic process to a conventional, continuously aerated, digestion process. During the second run, the aerobic–anoxic digester was compared to a lime-supplemented conventional aerobic process. The third run compared two aerobic–anoxic digester units, operating at reduced (50 and 25% of normal) aeration rates during the aerobic period. In addition, basic data from batch tests are outlined and discussed. Results from the various experimental runs indicated numerous potential advantages for the aerobic–anoxic mode of digester operation. The main advantage was that turning the air on and off resulted in volatile solids reduction efficiencies similar to that in the continuously aerated systems. In addition to the potential for significant savings in aeration costs, another benefit of the intermittent aeration mode of operation involved improved supernatant quality of the final, settled effluent. Key words: aerobic digestion, anoxic, intermittent aeration, lime, pilot-scale, Redox potential, sludge, solids reduction.

Irvine Welsh

2021 ◽  
Author(s):  
Craig Lamont
Keyword(s):  
Short Story ◽  
Film Adaptation ◽  
The Novel ◽  
Work Experiences ◽  
Late 20Th Century ◽  
Narrative Skills ◽  
Useful Life ◽  
One Year ◽  
Marabou Stork ◽  
Very High

Irvine Welsh is one of the most revered writers of his generation and is globally renowned for his debut novel Trainspotting (1993) and the film adaptation that followed. Though his biography is sketchy—perhaps deliberately so—we can say with some certainty that he was raised in Leith and Muirhouse, Scotland, and that he gained useful life and work experiences in London during the late 1970s and 1980s. His year of birth in Edinburgh is mainly given as 1958, though some reports offer an earlier date. Upon returning to Scotland in the late 1980s, he completed an MBA at Heriot-Watt University (his thesis was based on creating equal opportunities for women), and soon became acquainted with writers such as Alan Warner, Duncan McLean, and Kevin Williamson. Trainspotting was once a series of diary entries that were published in parts from 1991 onward in small independent magazines like DOG and Rebel Inc. Draft sections were also printed in A Parcel of Rogues and Past Tense: Four Stories from a Novel. It was through this network that Welsh became known to the director of Secker & Warburg, who published Trainspotting in its entirety. Set in the late 1980s, the novel was a critique of capitalism, individualism, nationalism, and war. This sweat-lashed, dialect-driven journey into the self and the nation was met with very high critical regard and a good measure of disgust. The novel is said to have missed out on the Booker Prize shortlist for causing offense to female judges. One year later James Kelman’s How Late It Was, How Late won the same award, much to the bemusement of one or two judges, and so the pair have been entwined as controversial antiestablishment types ever since. For Welsh, his reputation as a writer of mind-bending literature was enhanced with The Acid House (1994) and Marabou Stork Nightmares (1995), both showcasing an impressive range of narrative skills. Danny Boyle’s film version of Trainspotting (1996) propelled Welsh into a stratosphere that few Scottish writers have enjoyed, and while three more books were published before the sequel to Trainspotting, Porno (2002), he is chiefly remembered for creating one of the great novels of the late 20th century with his debut. Welsh’s extensive novels, short story collections, and stage and screen plays have kept him at the forefront of the Scottish literary scene, though he has revived the Trainspotting case time and again, most recently with Skagboys (2012), The Blade Artist (2016), and Dead Men’s Trousers (2018).

scholarly journals Selected Indigenous Saccharomyces cerevisiae Strains as Profitable Strategy to Preserve Typical Traits of Primitivo Wine

Fermentation ◽  
2019 ◽  
Vol 5 (4) ◽  
pp. 87 ◽  
Author(s):  
Capece ◽  
Pietrafesa ◽  
Siesto ◽  
Romaniello ◽  
Condelli ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Pilot Scale ◽  
Sensory Characteristics ◽  
Spontaneous Fermentation ◽  
Wine Production ◽  
Grape Must ◽  
High Dominance ◽  
Very High ◽  
Grape Must Fermentation

Wine production by inoculated fermentation with commercial Saccharomyces cerevisiae strains is an ordinary practice in modern winemaking in order to assure the final quality of wine, although this procedure results in the production of highly homogeneous wines. The use of indigenous selected starters represents a useful tool to control alcoholic grape must fermentation, safeguarding the typical sensory characteristics of wine produced from specific regions. In this study, we selected three indigenous S. cerevisiae strains among 16 indigenous strains previously isolated from the spontaneous fermentation of Primitivo grapes, which were collected from the vineyards of three different cellars. The three selected starters (one for each cellar) were tested during fermentations at pilot scale by performing in each cellar two trials: one with an indigenous starter (specific for the winery), and one with the commercial starter AWRI796 (common to all the cellars). Starter dominance ability and influence on aromatic quality of the wine were used as criteria to test the suitability of these indigenous starters to be used at the cellar scale. The results obtained in this study showed that the indigenous strains were characterized by very high dominance ability, and the aromatic quality of wine was strongly influenced both by the inoculated strain and the interaction strain/grape must.

Analisis Benchmarking Terhadap Kinerja Perusahaan Kontraktor Di Dinas Pupr Kota Blitar

REVITALISASI ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 56
Author(s):  
Dessy Kusuma Wardani ◽  
Edy Swasono
Keyword(s):  
Consumer Satisfaction ◽  
Success Factors ◽  
Successful Implementation ◽  
Company Performance ◽  
Community Satisfaction ◽  
Construction Work ◽  
Acquisition Rate ◽  
One Year ◽  
Construction Product

This study aims to identify the dominant factors of the successful implementation of benchmarking on the performance of contracting companies and test the significance of the application of benchmarking on the performance of contracting companies. The research sample was saturated samples of 65 qualified contractor companies. The method and type of research used were correlational methods of multiple regression analysis using SPPS. The results of the study concluded that 1.Benchmarking significantly influences the performance of contracting companies in the Blitar City DPUPR; 1. The ranking of success factors for the Blitar City contractor companies in the process of implementing benchmarking (1) planning, (2) data collection, (3) acception and action and (4) analysis; 2.Benchmarking has proven to significantly improve company performance as measured by increasing (1) Corporate Finance (2) Company productivity, (3) DPUPR Consumer Satisfaction, (4) Community Satisfaction, (5) Quality of the company's construction technical personnel, (6) Satisfaction employee work, (7) Project acquisition rate in one year, (8) Effective completion of construction work, (9) Construction product quality.

Health-related quality of life one year after surgical treatment of the type I chronic aortic dissection

2019 ◽  
Vol 38 (1) ◽  
Author(s):  
Oksana Kamenskaya ◽  
Asya Klinkova ◽  
Irina Loginova ◽  
Alexander Chernyavskiy ◽  
Dmitry Sirota ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Surgical Treatment ◽  
Aortic Dissection ◽  
Type I ◽  
Health Related Quality ◽  
Chronic Aortic Dissection ◽  
Related Quality ◽  
Health Related ◽  
One Year

Ground water quality of selected areas of Punjab and Sind Provinces, Pakistan: Chemical and microbiological aspects

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Ionic Concentration ◽  
Chloride Ions ◽  
Potassium Ions ◽  
Ammonium Ions ◽  
High Concentration ◽  
Phosphate Ions ◽  
Sodium Magnesium ◽  
Very High ◽  
Microbiological Aspects

The assessment of groundwater is essential for the estimation of suitability of water for safe use. An attempt has been made to study the groundwater of selected areas of Punjab (Sheikhupura & Sahiwal) and Sindh (Sindh, Jawar Dharki and Dharki), Pakistan. The results indicate that pH, color and odor were all within limits of WHO that is pH ranges 6.5–8.5, colorless and odorless, respectively. The high values of suspended solids were observed in the Sindh-1 and Dharki samples. Microbiologically only Sahiwal and Jawar Dharki were found fit for drinking purpose. Trace metals analysis of Sheikhupura-1 and Sindh-1 showed that values do not fall within limits of WHO for Iron. The ionic concentration analysis showed that high bicarbonate (HCO3-), ions are present in the samples of Sahiwal and Dharki; Sindh-1 and Jawar Dharki samples showed very high concentration for chloride ions, all samples were satisfactory level for sulphate (SO42-), sodium, magnesium and phosphate ions except samples of Sindh-1 and Jawar Dharki. High concentration of calcium and potassium ions was observed in samples of Sindh-1, while all other samples were found fit for drinking purposes in respect of nitrate, nitrite and ammonium ions. The high concentration of Fluoride was found only in Sheikhupura-2 samples.

Sign in / Sign up

Export Citation Format

Share Document