scholarly journals ALTERNATIVES OF DOMESTIC WASTEWATER SLUDGE DRYING PROCESSES FOR ENERGY RECOVERY : A REVIEW

2021 ◽  
Vol 20 (3) ◽  
pp. 44
Author(s):  
S. Camera ◽  
T. Pineda-Vásquez ◽  
F. M. Bianchi ◽  
L. S. Martins ◽  
E. Virmond ◽  
...  
Keyword(s):  
Moisture Content ◽  
New Technologies ◽  
Wastewater Treatment Plants ◽  
Chemical Properties ◽  
Domestic Wastewater ◽  
Combustion Products ◽  
Wastewater Sludge ◽  
Moisture Content Level ◽  
Conventional Drying ◽  
Sludge Drying

As communities grow, cities need to increase their capacity to collect and treat domestic wastewater. The need of larger domestic wastewater treatment plants and proper disposal of its solid waste has attracted the scientific community to research about new technologies that will use those systems and waste as a way to generate energy. The moisture content of a fuel effects the combustion products and the energy released by the reaction.  Therefore, in order to make biomass to be a viable fuel option, the technological and scientific challenges of the drying process of wastewater sludge must be faced and overcome so the lowest moisture content level is achieved. Conventional drying processes as for example, direct and indirect thermal drying, are commonly used. However, other processes using renewable energy as for example solar drying are also being studied by the scientist around the world. Moisture content, physical-chemical properties as for example, heating values, composition, ash fusibility are all relevant properties taken into consideration when choosing a fuel for a specific application. The herein review is intended to present some existing domestic wastewater drying processes, alternative ways of improving the efficiency of those processes.

scholarly journals Energy Content Of The Domestic Wastewater Sludge Dried In The Thermal Dryer

2018 ◽  
Vol 225 ◽  
pp. 03008
Author(s):  
M.S. Zakaria ◽  
Suhaimi Hassan ◽  
M.N. Faizairi
Keyword(s):  
Moisture Content ◽  
Energy Content ◽  
Initial Moisture Content ◽  
Domestic Wastewater ◽  
Wastewater Sludge ◽  
Screw Conveyor ◽  
Heating Value ◽  
Operating Condition ◽  
Short Period ◽  
Disposal Problem

Domestic Wastewater Sludge (DWS) is considered as one of the largest contributor waste in Malaysia. Converting this waste as an alternative fuel can eliminate the disposal problem and reduce the environmental issue that causes by this waste. However, the initial moisture content in DWS is around 90% and in order to convert this waste into useful solid fuel, the moisture content of this waste must be reduced to 20% and below. Thermal dryer is one of the efficient dryer for the DWS that is capable of drying the huge volume of DWS in a short period of time. This study focused on the energy usage by the thermal dryer with several operating condition and the effect to the Higher Heating Value (HHV) of DWS. Based on the study, the higher heating value of DWS obtained from the experimental of thermal dryer found to be comparable with the results obtained from other biomass types which is around 9-15.86 MJ/kg. After analysis and comparison of the energy from the dried DWS and energy consumed by the dryer, the best operating condition of the thermal dryer was at 275 kW of power rating with speed of 30 and 10 rpm (revolution per minute) of the screw conveyor in the feeder and dryer respectively.

Characteristics of Sludge Moisture Content Variation in Sludge Drying Reed Beds

2015 ◽  
Vol 768 ◽  
pp. 515-519
Author(s):  
Xin Nan Deng ◽  
Yu Bo Cui ◽  
Wei Gao ◽  
Rui Chen
Keyword(s):  
Moisture Content ◽  
Pilot Scale ◽  
Coarse Sand ◽  
Reed Beds ◽  
Conventional Drying ◽  
The Media ◽  
The Difference ◽  
Reed Bed ◽  
Sludge Drying ◽  
Media Layer

Sludge moisture content was investigated at different stages during the test. Pilot-scale sludge drying bed and sludge drying reed beds had the same size of 3 m×1 m×1.3 m, and the bed height consisted of a 65 cm media layer and a 65 cm extra height. The media layer is filled with slag (20 cm), gravel (20 cm), coarse sand (5 cm) and quartz sand (24.5 cm) from the bottom in turn. Unit 1 was a conventional sludge drying bed, unit 2 was a sludge drying reed bed. Unit 1 and unit 2 had ventilation pipes which were mounted on the drainage pipes. Unit 3 was a sludge drying reed bed without ventilation pipe. The waste activated sludge was feed into the three units periodically during the experiment. The experiment investigated the sludge moisture content. At the end of the operation, the sludge moisture content in three units decreased by 18.52%, 22.37%, and 20.68%, respectively. It was found that the dewatering effect of the sludge drying reed bed was better than the conventional drying bed. The effect of plant growth on sludge dewatering is greater than the ventilation, but the difference was not significant.

scholarly journals Sludge Stabilization Process, Drying Depth and Polymeric Material Addition: Implication on Nitrogen Content, Selected Chemical Properties and Land Requirement in Sand Drying Beds

Energies ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 6753
Author(s):  
Taruvinga Badza ◽  
Eyob H. Tesfamariam ◽  
Craig Cogger
Keyword(s):  
Polymeric Material ◽  
Wastewater Treatment Plants ◽  
Chemical Properties ◽  
Polymeric Materials ◽  
Nutrient Content ◽  
Land Area ◽  
N Content ◽  
Total N ◽  
Sludge Drying ◽  
Land Size

Drying beds are a simple and economical means to dewater municipal sludge and are widely used in places with a suitable climate for air-drying. However, research-based information on drying thickness/drying depth effects on nutrient content and land size requirements for sludge drying is scarce. In this study, aerobically digested (AeD), and anaerobically digested without polymer (AnDP0) and with polymer (AnDP1) sludge types were dried in sand drying beds at 5, 10, 15, 20 and 25 cm depths in South Africa. Measured nitrogen (N) fractions and other parameters were more strongly influenced by sludge types than by drying depth. Total N content followed the order of AeD > AnDP1 > AnDP0. Polymeric material addition tended to increase total and inorganic N content and reduce the length of sludge drying period and land size requirement. The study showed that larger land size is required to dry sludge at shallower depths, even though the sludge dried more quickly. Drying sludge at 15 cm was the best option across sludge types in winter, taking an average land area between 261 and 383 m2 over the fewest days of sludge drying, whereas in spring, drying at 20 to 25 cm depth was most favorable. The findings suggest that drying bed management can be based on land area requirements with little concern for biosolid quality changes. For wastewater treatment plants relying on drying in beds, adding polymeric materials may be beneficial where land area for drying beds is limited, but not otherwise. Therefore, land availability is critical in decision making for sustainable sludge drying thickness.

scholarly journals Computational modeling of biosludge drying

2021 ◽  
Vol 9 (8) ◽  
pp. 219-232
Author(s):  
Nayara Vilela Avelar ◽  
Ana Augusta Passos Rezende ◽  
Antonio Marcos de Oliveira Siqueira ◽  
Cláudio Mudadu Silva ◽  
Angélica de Cássia Oliveira Carneiro
Keyword(s):  
Moisture Content ◽  
Initial Moisture Content ◽  
Wastewater Sludge ◽  
Moisture Distribution ◽  
Drying Process ◽  
Urban Wastewater ◽  
Complex Process ◽  
Simulated Temperature ◽  
Sludge Drying ◽  
Good Agreement

Considerable increases in industrial and urban wastewater sludge generation in recent years require proper treatment, such as thermal drying, and disposal. The sludge drying is a complex process involving simultaneous and coupled heat and mass transfer, which can be modeled by taking into account mass and heat balances, and assuming that water diffuses according to kinetic laws. This research implemented a simulation model for biosludge drying processes to predict the temperature and moisture distribution inside the biosludge, using the COMSOL Multiphysics® simulation program v5.2. A parametric analysis was carried out to determine the effect of initial moisture content on biosludge final temperature and moisture reduction. The simulated temperature and moisture content were experimentally validated and good agreement was observed between the simulation and experimental results. This model is a useful tool to optimize the drying process and develop better strategies for the control of the system.

scholarly journals Fuel Characterization Study and Simulation of Dewatered Domestic Wastewater Sludge Gasification Using ASPEN Plus

2019 ◽  
Vol 2 (3) ◽  
pp. 954-963
Author(s):  
Aboubaker AbdallaIbrahim Ali ◽  
Hüseyin Akilli
Keyword(s):  
Moisture Content ◽  
Initial Moisture Content ◽  
Domestic Wastewater ◽  
Aspen Plus ◽  
Proximate Analysis ◽  
Wastewater Sludge ◽  
Heating Value ◽  
High Heating Value ◽  
High Heating ◽  
Fuel Characterization

Dewatered domestic wastewater sludge (DDWS) is one of the largest contributors of waste material in the world, and it immediately elevates local environmental problems, especially in the urban area. The conversion of this material into a usable form of green energy, such as syngas through gasification, can be a vital solution. Hence, this method not only solves the environmental issues related to DDWS disposal but also participates as an energy source. To achieve this goal, the essential fuel characterization, which includes initial moisture content, high heating value, ultimate analysis, and proximate analysis, were carried out to assess the potential energy in DDWS. Due to the high expenses of the successful design of the gasifier reactor, and there are no efficient methods to predict the gasification performance, the model of the DDWS gasification process using ASPEN Plus software was developed. As ASPEN Plus software does not contain a built-in gasifier reactor model, a combination of various reactors is used to simulate the gasification processes. These processes were divided out into two stages. In the first stage, DDWS was decomposed into its element by specifying yield distribution. By using Gibbs free energy minimization approach, the gasification reactions were modeled. The current model was validated with the previously published work. From the characterization findings, DDWS showed high initial moisture content 84.64% and potential energy with 16.84 MJ/kg high heating value. The proximate analysis based on the dry base of DDWS exhibited that more than 55.42 % of their mass is composed of volatile materials, and ash content is found to be less than 25.79%.

Sludge minimization by disintegration at different wastewater treatment plants

2008 ◽  
Vol 3 (1) ◽  
Author(s):  
Luchien Luning ◽  
Paul Roeleveld ◽  
Victor W.M. Claessen
Keyword(s):  
Organic Matter ◽  
Wastewater Treatment ◽  
Anaerobic Digestion ◽  
Sewage Sludge ◽  
New Technologies ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Biological Degradation ◽  
Ongoing Research ◽  
Sludge Minimization

In recent years new technologies have been developed to improve the biological degradation of sewage sludge by anaerobic digestion. The paper describes the results of a demonstration of ultrasonic disintegration on the Dutch Wastewater Treatment Plant (WWTP) Land van Cuijk. The effect on the degradation of organic matter is presented, together with the effect on the dewatering characteristics. Recommendations are presented for establishing research conditions in which the effect of sludge disintegration can be determined in a more direct way that is less sensitive to changing conditions in the operation of the WWTP. These recommendations have been implemented in the ongoing research in the Netherlands supported by the National Institute for wastewater research (STOWA).

Bottlenecks in the Implementation of On-Site Wastewater Treatment Plants on a Large Scale in The Netherlands

1990 ◽  
Vol 22 (3-4) ◽  
pp. 291-298
Author(s):  
Frits A. Fastenau ◽  
Jaap H. J. M. van der Graaf ◽  
Gerard Martijnse
Keyword(s):  
Wastewater Treatment ◽  
The Netherlands ◽  
Large Scale ◽  
Wastewater Treatment Plants ◽  
Housing Stock ◽  
Research Work ◽  
Field Research ◽  
Domestic Wastewater ◽  
Research Programme ◽  
Definition Of

More than 95 % of the total housing stock in the Netherlands is connected to central sewerage systems and in most cases the wastewater is treated biologically. As connection to central sewerage systems has reached its economic limits, interest in on-site treatment of the domestic wastewater of the remaining premises is increasing. A large scale research programme into on-site wastewater treatment up to population equivalents of 200 persons has therefore been initiated by the Dutch Ministry of Housing, Physical Planning and Environment. Intensive field-research work did establish that the technological features of most on-site biological treatment systems were satisfactory. A large scale implementation of these systems is however obstructed in different extents by problems of an organisational, financial and/or juridical nature and management difficulties. At present research is carried out to identify these bottlenecks and to analyse possible solutions. Some preliminary results are given which involve the following ‘bottlenecks':-legislation: absence of co-ordination and absence of a definition of ‘surface water';-absence of subsidies;-ownership: divisions in task-setting of Municipalities and Waterboards; divisions involved with cost-sharing;-inspection; operational control and maintenance; organisation of management;-discharge permits;-pollution levy;-sludge disposal. Final decisions and practical elaboration of policies towards on-site treatment will have to be formulated in a broad discussion with all the authorities and interest groups involved.

scholarly journals Possibilities of Decreasing Hygroscopicity of Resonance Wood Used in Piano Soundboards Using Thermal Treatment

2021 ◽  
Vol 11 (2) ◽  
pp. 475
Author(s):  
Petr Zatloukal ◽  
Pavlína Suchomelová ◽  
Jakub Dömény ◽  
Tadeáš Doskočil ◽  
Ginevra Manzo ◽  
...  
Keyword(s):  
Moisture Content ◽  
Conversion Efficiency ◽  
Dynamic Modulus ◽  
Moisture Sorption ◽  
Acoustical Properties ◽  
Longitudinal Dynamic ◽  
Moisture Content Level ◽  
Longitudinal Sound Velocity ◽  
Tan Δ ◽  
Resonance Wood

This article presents the possibilities of decreasing moisture sorption properties via thermal modification of Norway spruce wood in musical instruments. The 202 resonance wood specimens that were used to produce piano soundboards have been conditioned and divided into three density groups. The first specimen group had natural untreated properties, the second was thermally treated at 180 °C, and the third group was treated at 200 °C. All specimens were isothermally conditioned at 20 °C with relative humidity values of 40, 60, and 80%. The equilibrium moisture content (EMC), swelling, and acoustical properties, such as the longitudinal dynamic modulus (E’L), bending dynamic modulus (Eb), damping coefficient (tan δ), acoustic conversion efficiency (ACEL), and relative acoustic conversion efficiency (RACEL) were evaluated on every moisture content level. Treatment at 180 °C caused the EMC to decrease by 36% and the volume swelling to decrease by 9.9%. Treatment at 200 °C decreased the EMC by 42% and the swelling by 39.6%. The 180 °C treatment decreased the value of the longitudinal sound velocity by 1.6%, whereas the treatment at 200 °C increased the velocity by 2.1%. The acoustical properties EL′, Eb, ACEL, and RACEL were lower due to the higher moisture content of the samples, and only the tanδ increased. Although both treatments significantly affected the swelling and EMC, the treatment at 180 °C did not significantly affect the acoustical properties.

scholarly journals Effect of Addition of Green Coffee Parchment on Structural, Qualitative and Chemical Properties of Gluten-Free Bread

Foods ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 5
Author(s):  
Paola Littardi ◽  
Massimiliano Rinaldi ◽  
Maria Grimaldi ◽  
Antonella Cavazza ◽  
Emma Chiavaro
Keyword(s):  
Moisture Content ◽  
Oxidative Stability ◽  
Water Activity ◽  
Chemical Properties ◽  
Antioxidant Compounds ◽  
Total Phenol Content ◽  
Green Coffee ◽  
Gluten Free ◽  
Wet Processing ◽  
Total Antioxidant

Green coffee parchment (GCP) is becoming interesting, due to the diffusion of wet processing in which coffee parchment is collected separately; it is one of the less studied coffee by-products, but it is reported to be rich in phenolic compounds and dietary fiber. The addition of GCP (355–500 μm) at 2 % to gluten-free breads was investigated in terms of physical properties (volume, moisture content, water activity, crumb grain, texture, and color), total antioxidant capacity (TAC) and total phenol content during three days of storage. Moreover, the effects of GCP on sensorial characteristics, 5-hydroxymethylfurfural (HMF), and oxidative stability was evaluated. From the sensorial analysis, bread with 2% addition resulted in being acceptable for consumers with no significant differences from the control, while 4% of GCP was discarded by consumers, as it resulted in being too bitter. Moreover, GCP at 2% addition did not modify volume, moisture content, and water activity. On the contrary, GCP deeply affected the color with a darker aspect that was appreciated by consumers. Regarding texture, 2% of GCP did not affect hardness, cohesiveness, and staling process during storage. Interestingly, 2% of GCP significantly improved the TAC and oxidative stability of the bread; in accordance with these results, 2% of GCP reduced the HMF content, thanks to its antioxidant compounds.

scholarly journals Efficiency and Technological Reliability of Contaminant Removal in Household WWTPs with Activated Sludge

2021 ◽  
Vol 11 (4) ◽  
pp. 1889 ◽  
Author(s):  
Agnieszka Micek ◽  
Krzysztof Jóźwiakowski ◽  
Michał Marzec ◽  
Agnieszka Listosz ◽  
Tadeusz Grabowski
Keyword(s):  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Pollutant Removal ◽  
Treated Wastewater ◽  
Contaminant Removal ◽  
Nitrogen And Phosphorus ◽  
Wastewater Samples ◽  
Polish Law

The results of research on the efficiency and technological reliability of domestic wastewater purification in two household wastewater treatment plants (WWTPs) with activated sludge are presented in this paper. The studied facilities were located in the territory of the Roztocze National Park (Poland). The mean wastewater flow rate in the WWTPs was 1.0 and 1.6 m3/day. In 2017–2019, 20 series of analyses were done, and 40 wastewater samples were taken. On the basis of the received results, the efficiency of basic pollutant removal was determined. The technological reliability of the tested facilities was specified using the Weibull method. The average removal efficiencies for the biochemical oxygen demand in 5 days (BOD5) and chemical oxygen demand (COD) were 66–83% and 62–65%, respectively. Much lower effects were obtained for total suspended solids (TSS) and amounted to 17–48%, while the efficiency of total phosphorus (TP) and total nitrogen (TN) removal did not exceed 34%. The analyzed systems were characterized by the reliability of TSS, BOD5, and COD removal at the level of 76–96%. However, the reliability of TN and TP elimination was less than 5%. Thus, in the case of biogenic compounds, the analyzed systems did not guarantee that the quality of treated wastewater would meet the requirements of the Polish law during any period of operation. This disqualifies the discussed technological solution in terms of its wide application in protected areas and near lakes, where the requirements for nitrogen and phosphorus removal are high.

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