Managing Change in an Environmentally Conscious Society: A Case Study, Gothenburg (Sweden)

1990 ◽  
Vol 22 (12) ◽  
pp. 45-56 ◽  
Author(s):  
P. Balmer ◽  
R. C. Frost
Keyword(s):  
Land Reclamation ◽  
Public Attitudes ◽  
Public Support ◽  
Treatment Plant ◽  
Digested Sludge ◽  
Environmentally Conscious ◽  
Managing Change ◽  
Underground Cavities ◽  
Anaerobically Digested Sludge

The treatment and disposal of sewage sludge in environmentally conscious societies is becoming increasingly problematical due, in large part, to public attitudes. Strategies have to be developed which either successfully defend existing routes or which manage changes that have public support. A case study of managing change at a large wastewater treatment plant, serving Gothenburg, Sweden, is presented. Three radically different alternatives to the current practice, of lime addition to dewatered raw sludge and disposal to land reclamation, were appraised to a common set of criteria and compared with the existing route. The options considered were incineration, drying of dewatered anaerobically digested sludge, and disposal of dewatered anaerobically digested sludge to underground cavities. An account is given of the public discussion meetings that were held at strategically important times, the views expressed at these being taken into account by GRYAAB's management board in their decision to opt for the disposal of sludge to underground cavities.

Characterization of raw sludge, chemically modified sludge and anaerobically digested sludge in Hong Kong

1998 ◽  
Vol 38 (2) ◽  
pp. 25-32 ◽  
Author(s):  
C. W. Chu ◽  
C. S. Poon ◽  
R. Y. H. Cheung
Keyword(s):  
Hong Kong ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Chemical Properties ◽  
Primary Treatment ◽  
Digested Sludge ◽  
Total N ◽  
Chemically Modified ◽  
Anaerobically Digested Sludge

Chemically Enhanced Primary Treatment (CEPT) or Chemically Assisted Primary Sedimentation (CAPS) is being employed at the new sewage work on Stonecutters Island as part of the Strategic Sewage Disposal Scheme (SSDS) in Hong Kong. CAPS involves the use of chemical coagulants (such as lime or ferric chloride) to induce coagulation or flocculation and let these finely-divided particles form large aggregates (floc) so that they can settle out within a reasonable period of time. In this study, five sludge samples collected from different sewage treatment plants in Hong Kong were physically and chemically characterized. They were chemically modified sludge from Stonecutters Island (CAPS) raw sludge from Tai Po and Yuen Long Sewage Treatment Plant (STP) (rTP & rYL) and anaerobically digested sludge from Tai Po and Yuen Long STP (dTP & dYL). It was found that CAPS sludge was better than other 4 sludge samples in terms of settleability and dewaterability. CAPS sludge contained significant higher amounts (p<0.01) of extractable compounds than other sludges (except NO3− for dTP, NH4+ and PO43− for dYL). The concentration of total N and P in CAPS sludge were significantly higher (p<0.01) than other sludges (except dYL). The concentrations of total Cu, Pb, Ni, Cd, Cr and K in the CAPS sludge were also significantly higher (p<0.01) than other sludge samples. Most of the metals (Cr, Pb, Cr and Zn) in CAPS sludge were associated with the organically-bounded phase. It is concluded that there are significant differences in both physical and chemical properties between the chemically modified sludge and biological treated sludges.

Total nitrogen removal from high-strength ammonia recycle stream using a single submerged attached growth bioreactor

2007 ◽  
Vol 55 (8-9) ◽  
pp. 59-65 ◽  
Author(s):  
A. Onnis-Hayden ◽  
P.B. Pedros ◽  
J. Reade
Keyword(s):  
Total Nitrogen ◽  
Nitrogen Removal ◽  
Removal Rate ◽  
Treatment Plant ◽  
High Strength ◽  
Nitrogen Loading ◽  
Digested Sludge ◽  
Attached Growth ◽  
Anaerobically Digested Sludge ◽  
Total Nitrogen Removal

An experimental study investigating the nitrogen removal efficiency from the recycle stream generated in the dewatering facility of the anaerobically digested sludge at the Deer Island wastewater treatment plant (WWTP) in Boston was conducted using a single submerged attached growth bioreactor (SAGB), designed for simultaneous nitrification and denitrification. The applied nitrogen loading to the reactor ranged from 0.7 to 2.27 kg-N/m3·d, and the corresponding total nitrogen (TN) removal rate ranged from 0.38 to 1.8 kg-N/m3·d. The observed nitrification rates varied from 0.42 kg-N/m3·d to 1.45 kg-N/m3·d with an ammonia load of 0.5 kg-N/m3·d and 1.8 kg-N/m3·d, respectively. An average nitrification efficiency of 91% was achieved throughout the experiment. Denitrification efficiency varied from 55%, obtained without any addition of carbon source, to 95% when methanol was added in order to obtain a methanol/nitrate ratio of about 3 kg methanol/kg NO3−-N.

scholarly journals Integrated Membrane Process for the Treatment and Reuse of Residual Table Olive Fermentation Brine and Anaerobically Digested Sludge Centrate

Membranes ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 253
Author(s):  
Carlos Carbonell-Alcaina ◽  
Jose Luis Soler-Cabezas ◽  
Amparo Bes-Piá ◽  
María Cinta Vincent-Vela ◽  
Jose Antonio Mendoza-Roca ◽  
...  
Keyword(s):  
Organic Matter ◽  
Municipal Wastewater ◽  
Forward Osmosis ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Transmembrane Pressure ◽  
Municipal Wastewater Treatment ◽  
Digested Sludge ◽  
Anaerobically Digested Sludge ◽  
Table Olive

Management of wastewater is a major challenge nowadays, due to increasing water demand, growing population and more stringent regulations on water quality. Wastewaters from food conservation are especially difficult to treat, since they have high salinity and high organic matter concentration. The aim of this work is the treatment of the effluent from a table olive fermentation process (FTOP) with the aim of reusing it once the organic matter is separated. The process proposed in this work consists of the following membrane-based technologies: Ultrafiltration (UF) (UP005, Microdyn Nadir), Forward Osmosis (FO) (Osmen2521, Hydration Technology Innovation) and Nanofiltration (NF) (NF245, Dow). The FO process was implemented to reduce the salinity entering the NF process, using the FTOP as draw solution and, at the same time, to concentrate the centrate produced in the sludge treatment of a municipal wastewater treatment plant with the aim of obtaining a stream enriched in nutrients. The UF step achieved the elimination of 50% of the chemical oxygen demand of the FTOP. The UF permeate was pumped to the FO system reducing the volume of the anaerobically digested sludge centrate (ADSC) by a factor of 3 in 6.5 h. Finally, the ultrafiltrated FTOP diluted by FO was subjected to NF. The transmembrane pressure needed in the NF stage was 40% lower than that required if the ultrafiltration permeate was directly nanofiltered. By means of the integrated process, the concentration of organic matter and phenolic compounds in the FTOP decreased by 97%. Therefore, the proposed process was able to obtain a treated brine that could be reused in other processes and simultaneously to concentrate a stream, such as the ADSC.

Effect of daylight on regrowth of bacteria in anaerobically digested sludge

2010 ◽  
Vol 62 (2) ◽  
pp. 364-369 ◽  
Author(s):  
İrep Gözen ◽  
Banu Örmeci
Keyword(s):  
Clostridium Perfringens ◽  
Treatment Plant ◽  
Storage Period ◽  
Total Coliform ◽  
The Other ◽  
Masking Effect ◽  
Digested Sludge ◽  
Sludge Cake ◽  
Anaerobically Digested Sludge ◽  
Presence And Absence

This study investigated the regrowth of total coliform, Salmonella, and Clostridium perfringens in anaerobically digested sludge after centrifuge dewatering in the presence and absence of daylight. Sludge cake and centrate samples were collected from a treatment plant, and half of the samples was stored in daylight and the other half was stored in dark for three weeks. The bacteria levels in the cake and centrate samples were measured periodically throughout the storage period, and all three bacteria showed substantial regrowth. Presence of daylight increased the regrowth of Salmonella both in sludge cake and centrate, and increased the regrowth of total coliform in centrate. Salmonella exhibited the highest regrowth rate in cake among the three bacteria tested both in the presence and absence of light. Daylight did not appear to have a significant impact on the regrowth of Clostridium perfringens in cake and centrate, and on the regrowth of total coliform in cake. This might, however, be caused by the masking effect of the higher initial numbers of these bacteria in the samples. There is need for more research to thoroughly understand the effect of daylight on the regrowth of sludge bacteria.

scholarly journals Thermal Hydrolysis of Sewage Sludge: A Case Study of a WWTP in Burgos, Spain

2021 ◽  
Vol 11 (3) ◽  
pp. 964
Author(s):  
José García-Cascallana ◽  
Xiomar Gómez Barrios ◽  
E. Judith Martinez
Keyword(s):  
Treatment Plant ◽  
Electricity Production ◽  
Thermal Hydrolysis ◽  
Mass Balances ◽  
Digested Sludge ◽  
Hydrolysis Process ◽  
Base Scenario ◽  
Mesophilic Digestion ◽  
Hydrolysis Of

An evaluation of the energy and economic performance of thermal hydrolysis technologies is carried out on a theoretical basis. The wastewater treatment plant (WWTP) of Burgos (Spain) was the base scenario of this evaluation. Energy and mass balances were established considering the registered data of primary and secondary thickened sludge in the WWTP for 2011 to 2016. These balances were analysed considering five different scenarios, taking as Scenario 1, the plant operating with conventional mesophilic digestion. The scenarios considered commercially available technologies. The best results were obtained when hydrolysis was applied to digested sludge and sludge from the Solidstream® process. These two scenarios showed the best performance regarding volatile solid removal and lower demand for live steam, achieving a higher amount of biogas available for valorisation using combined heat and power (CHP) units. The main advantage of the hydrolysis process is the decrease in the volume of digesters and the amount of dewatered sludge needing final disposal. The Solidstream® process allowed a 35% increase in biogas available for engines and a 23% increase in electricity production.

Reduction of the content of organic micropollutants in digested sludge by a post-aeration process - a full-scale demonstration

2000 ◽  
Vol 42 (9) ◽  
pp. 111-118 ◽  
Author(s):  
L. Knudsen ◽  
G. H. Kristensen ◽  
P. E. Jørgensen ◽  
S.-E. Jepsen
Keyword(s):  
Treatment Plant ◽  
Full Scale ◽  
Wastewater Sludge ◽  
Biological Degradation ◽  
Organic Micropollutants ◽  
Digested Sludge ◽  
Limit Values ◽  
Anaerobically Digested Sludge ◽  
Aeration Process ◽  
First Time

Surplus wastewater sludge reused for agricultural purposes must observe certain limit values with respect to different xenobiotic substances. The latest revision of the statutory order in Denmark includes for the first time a list of limit values on organic micropollutants in sludge. Four groups of micropollutants are included in the list (LAS, PAH, NPE, and DEHP). The limit values will be revised in June 2000, at which time up to 50% of the sludge used for agricultural purposes, will not comply with the standards. It has been observed that the level of organic micropollutants is much higher in anaerobically digested sludge than in aerobically stabilised sludge. This indicates that the organic micropollutants in question can be partly or fully degraded under aerobic conditions but not under anaerobic conditions. The observations have formed the basis of the development of a post-aeration process for biological degradation of organic micropollutants in anaerobically digested sludge with the aim of enabling continued reuse of the sludge for agricultural purposes. The process is presented in this paper together with a description of a full scale demonstration experience on a Danish wastewater treatment plant © 1999, IAWQ. Published by Elsevier Science Ltd.

A multiple extraction–centrifugation method for the recovery of viruses from waste water treatment plant effluents and sludges

1983 ◽  
Vol 29 (12) ◽  
pp. 1661-1670 ◽  
Author(s):  
Margaret A. Lewis ◽  
Michael W. Nath ◽  
J. C. Johnson
Keyword(s):  
Waste Water Treatment ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Waste Water Treatment Plant ◽  
Digested Sludge ◽  
Primary Sludge ◽  
Virus Adsorption ◽  
Monitoring Study ◽  
Anaerobically Digested Sludge ◽  
Virus Recovery

Absorption of 14C-labelled poliovirus-2 to sedimentable solids of primary sludge samples collected from a secondary treatment facility during a 6-month period averaged 94%; for anaerobically digested sludge, 99%. The extent of virus adsorption was influenced by the amount of solids. Maximal adsorption occurred at or above 0.5% solids with sludge diluted with deionized water and above 1.5% solids when diluted with the respective particle-free sludge supernatants. A Tris–HCl buffer containing NaCl, glycerol, and serum was found to efficiently elute poliovirus-2 from primary sludge solids. By means of re-extraction and concentration by centrifugation (the TEC procedure), the average recoveries of poliovirus-2 were 92–94% based upon either infectivity or radioactivity analyses. Similarly, recoveries were 90–92% for poliovirus-2 in digested sludge. Maximum elution was dependent upon all four TEC buffer components and the restriction of solids to≤ 1.0%. The procedure was found to be more efficient than glycine–NaOH and Freon procedures or elution with beef embryo extract. As adapted for effluents the procedure increased the yield and improved the consistency of virus recovery. The arithmetic mean titers obtained during a monitoring study for primary and digested sludge were 4.2 × 105 and 5.1 × 103 plaque-forming units (pfu)/L; for primary, secondary, and final effluents 2.3 × 105, 4.7 × 103, and 4.7 × 102 pfu/L, respectively.

scholarly journals Rheology and friction loss of raw and digested sewage sludge with high TSS concentrations: a case study

2018 ◽  
Vol 2017 (1) ◽  
pp. 276-286 ◽  
Author(s):  
K. Füreder ◽  
K. Svardal ◽  
J. Krampe ◽  
H. Kroiss
Keyword(s):  
Shear Stress ◽  
Sewage Sludge ◽  
Pilot Plant ◽  
Treatment Plant ◽  
Operating Conditions ◽  
Friction Loss ◽  
Rheological Parameters ◽  
Municipal Sewage Sludge ◽  
Digested Sludge

Abstract High total suspended solids (TSS) digestion of municipal sewage sludge reduces the required space and volume for digestion plants. However, an important consequence of high TSS is the major influence on sludge rheology. The present case study investigates the rheology of sludge from a 130 m3 high solids digestion pilot plant at Vienna's main wastewater treatment plant (4 M PE120). Raw sludge ranged from 6 to 8% TSS and digested sludge from 3.2 to 4.6%. TSS show an exponential impact on rheological parameters. Increasing raw sludge TSS from 6 to 8% at least doubles the shear stress and increases friction loss by a factor of three. However, under real operating conditions simulated at the pilot plant, there are additional impact factors. The mixing ratio between waste activated and primary sludge influences raw sludge rheology, while solids retention time and loss on ignition affects digested sludge rheology. Nevertheless, friction loss calculations based on a simple power law relationship between shear rate and shear stress proved to be applicable and sufficiently accurate for both raw and digested sludge with high TSS. Altogether, this case study underlines the relevance of comprehensive rheological considerations, measurements and calculations when designing high TSS sludge digestion.

Sign in / Sign up

Export Citation Format

Share Document