scholarly journals Full-Scale Municipal Sludge Pyrolysis in China: Design Fundaments, Environmental and Economic Assessments, and Future Perspectives

2021 ◽  
Author(s):  
Hongxi Luo ◽  
Fangwei Cheng ◽  
Bin Yu ◽  
Lei Hu ◽  
Junfa Zhang ◽  
...  
Keyword(s):  
Moisture Content ◽  
Economic Performance ◽  
Environmental Sustainability ◽  
Economic Assessment ◽  
System Size ◽  
Organic Content ◽  
Full Scale ◽  
Municipal Sludge ◽  
Thermochemical Process ◽  
Gas Consumption

The increasing amount of municipal sludge in China requires safe and effective management to protect human health and ensure environmental sustainability. Pyrolysis is a thermochemical process that that decompose organic matter at elevated temperature and under anaerobic conditions, and it has attracted an increasing attention in sludge treatment in the recent years. However, comprehensive environmental and economic assessment of sludge pyrolysis in China's context is rare, due to the small quantities of full-scale sludge pyrolysis plant. In this paper, we applied our design and operation parameters of full-scale sludge pyrolysis plants to generate the material and energy consumptions of the pyrolysis system under various of conditions, including sludge organic content and moisture content, system size, system energy distribution, and whether or not heat substitution is applied. Life cycle assessment and techno-economic assessment were then applied to investigate the environmental and economic performance of the system Our results demonstrate the significant environmental and economic impacts associated with sludge properties and system size. Generally, sludge with higher organic content and lower moisture content requires less natural gas consumption, which leads to a simultaneous improvement of the system environmental and economic performance. The system economic performance is more sensitive to the system size, and centralized sludge handling using a larger pyrolysis is more economic favorable. In the most ideal case, the average global warming potential and minimum sludge handling price of sludge pyrolysis could be as low as -32.5 kg CO2-Eq/t DS and 188.8 $/t DS, respectively. Based on these results, we discussed the pathways that could be taken to further optimize the environmental and economic performances of the pyrolysis system.

Evaluation of Municipal Sludge Drying and Dewatering with Respect to Sludge Volume Reduction

1990 ◽  
Vol 22 (12) ◽  
pp. 153-161 ◽  
Author(s):  
Maryla Smollen
Keyword(s):  
Moisture Content ◽  
Treatment Strategies ◽  
Vacuum Drying ◽  
Municipal Sludge ◽  
Moisture Retention ◽  
Sludge Dewatering ◽  
Sludge Treatment ◽  
Energy Inputs ◽  
Retention Characteristics ◽  
Sludge Drying

A number of parameters that influence sludge dewatering behaviour have been identified, but there is a lack of consensus which of these are of the greatest concern in sludge treatment strategies. Moisture retention characteristics were obtained from vacuum drying of centrifuged sludge samples to subdivide moisture into immobilised, physically and chemically bound fractions. Physically bound moisture is responsible for unsatisfactory dewatering by centrifugation. Polyelectrolyte releases some of the immobilised water, but simultaneously increases the physically bound moisture content which gives rise to large energy inputs during mechanical dewatering. Commonly used dewaterability measurements do not appear to be linked to moisture retention characteristics.

scholarly journals Study on the soil corrosivity towards the buried water supply pipelines in Madhyapur Thimi municipality, Bhaktapur

BIBECHANA ◽  
2014 ◽  
Vol 11 ◽  
pp. 94-102
Author(s):  
Kumar P Dahal ◽  
Dinesh KC ◽  
Jagadeesh Bhattarai
Keyword(s):  
Cast Iron ◽  
Moisture Content ◽  
Water Supply ◽  
Reduction Potential ◽  
Organic Content ◽  
Galvanized Steel ◽  
Soil Parameters ◽  
Simple Modification ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential

This research work is carried out to identify the corrosive nature of soils towards the buried-galvanized steel and cast iron pipelines buried in Sanothimi areas of Madhyapur Thimi municipality, Bhaktapur based on different soil parameters such as organic content, moisture content, pH, resistivity, oxidation-reduction potential, chloride and sulfate ions. The soil parameters of the collected soil samples from the study areas were analyzed using standard ASTM methods. Concentrations of these soil parameters measured in this study were found as: organic content (0.9- 7.9%), moisture content (8.0-36.7%), pH (6.8-7.7), resistivity (3900-16700 ohm.cm), oxidation-reduction potential (337-461 mV vs SHE), chloride (25-71 ppm) and sulfate (35-464 ppm) contents. These soil parameters gave an indication of “mildly corrosive” to “less corrosive” nature of soils on the galvanized steels and cast iron pipelines buried in the study areas. Based on the findings of the present studies, it can be advised to the related authorities or local people that simple modification of the soils by using cheapest non-conducting materials like gravel or sand around the buried water supply pipelines before undergrounding them in the study areas is very beneficial from the corrosion point of view to increase their life time. DOI: http://dx.doi.org/10.3126/bibechana.v11i0.10387 BIBECHANA 11(1) (2014) 94-102

Development of calibration algorithms for selected water content reflectometry probes for burned and non-burned organic soils of Alaska

2010 ◽  
Vol 19 (7) ◽  
pp. 961 ◽  
Author(s):  
Laura L. Bourgeau-Chavez ◽  
Gordon C. Garwood ◽  
Kevin Riordan ◽  
Benjamin W. Koziol ◽  
James Slawski
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Water Content ◽  
Soil Profile ◽  
Soil Moisture Content ◽  
Mineral Soil ◽  
Organic Soil ◽  
Organic Content ◽  
Organic Soils ◽  
Probe Type

Water content reflectometry is a method used by many commercial manufacturers of affordable sensors to electronically estimate soil moisture content. Field‐deployable and handheld water content reflectometry probes were used in a variety of organic soil‐profile types in Alaska. These probes were calibrated using 65 organic soil samples harvested from these burned and unburned, primarily moss‐dominated sites in the boreal forest. Probe output was compared with gravimetrically measured volumetric moisture content, to produce calibration algorithms for surface‐down‐inserted handheld probes in specific soil‐profile types, as well as field‐deployable horizontally inserted probes in specific organic soil horizons. General organic algorithms for each probe type were also developed. Calibrations are statistically compared to determine their suitability. The resulting calibrations showed good agreement with in situ validation and varied from the default mineral‐soil‐based calibrations by 20% or more. These results are of particular interest to researchers measuring soil moisture content with water content reflectometry probes in soils with high organic content.

scholarly journals Automatic Monitoring and Cutoff of Peanut Dryers

1984 ◽  
Vol 11 (2) ◽  
pp. 58-60 ◽  
Author(s):  
Paul D. Blankenship ◽  
James I. Davidson
Keyword(s):  
Weight Loss ◽  
Moisture Content ◽  
Automatic Monitoring ◽  
Full Scale ◽  
Test Results ◽  
Initial Weight ◽  
Moisture Control ◽  
Final Weight ◽  
Conventional Methods

Abstract A method for automatic cutoff of full-scale peanut dryers when peanuts approach a prescribed moisture content without periodic moisture sampling is described. Final weight is mathematically predicted from initial weight and moisture content. Peanut weight loss is monitored and dryer operation subsequently controlled through electronics. Six of 8 drying wagon loads of peanuts dried with the method were dried to a satisfactory moisture content at grading. Additional drying was required on 2 loads. Test results indicate that the method will require less labor, provide better moisture control, and reduce the danger of overdrying compared to conventional methods.

Effects of surfactants originating from reuse of greywater on capillary rise in the soil

2005 ◽  
Vol 52 (10-11) ◽  
pp. 157-166 ◽  
Author(s):  
A.W. Shafran ◽  
A. Gross ◽  
Z. Ronen ◽  
N. Weisbrod ◽  
E. Adar
Keyword(s):  
Moisture Content ◽  
Environmental Sustainability ◽  
Capillary Rise ◽  
Agricultural Productivity ◽  
Laundry Detergent ◽  
Domestic Wastewater ◽  
Water Repellent ◽  
Detergent Solution ◽  
Household Gardens ◽  
Irrigated Soils

Greywater is all domestic wastewater excluding toilet effluents. Detergents contain surfactants, which account for the highest concentration of organic chemicals in average domestic wastewater. Accumulation of surfactants in greywater-irrigated soils was determined in three household gardens. The effect of surfactants on capillary rise in loess and sand was then tested in the range of concentrations found in the garden soils. The capillary rise of freshwater in sieved oven-dried soil mixed with different concentrations of laundry detergent solution (10% w/w moisture content) was determined. In a second setup, the soil was mixed with freshwater and the rising solution contained different concentrations of detergent solution. The introduction of laundry solution to the soils caused a significant decrease in the capillary rise over the range of concentrations that is found in greywater-irrigated soils. The effect was more noticeable in the sand than in the loess. Interestingly, in the second setup, the capillary rise of the laundry solutions in the sand was almost similar to that of freshwater, whereas in the loess the capillary rise was significantly reduced. It is suggested that accumulation of surfactants in the soil might form water repellent soils that have a significant effect on agricultural productivity and environmental sustainability.

scholarly journals Monitoring accumulation sediment characteristics in full scale sewer physical model with urban wastewater

2017 ◽  
Vol 76 (1) ◽  
pp. 115-123 ◽  
Author(s):  
Manuel Regueiro-Picallo ◽  
Juan Naves ◽  
Jose Anta ◽  
Joaquín Suárez ◽  
Jerónimo Puertas
Keyword(s):  
Accumulation Rate ◽  
Sediment Accumulation ◽  
Treatment Plant ◽  
Organic Content ◽  
Full Scale ◽  
Scale Model ◽  
Experimental Conditions ◽  
Sediment Distribution ◽  
Wastewater Quality ◽  
Series Of Experiments

A series of experiments were carried out with real wastewater in a pilot flume located at A Coruña wastewater treatment plant (WWTP) (Spain). A full scale model was developed to test a circular (300 mm inner diameter) and an equivalent area egg-shaped plastic pipe under controlled experimental conditions (pipe slope 2–5‰, averaged discharge Q = 4 L/s). Velocity profiles and sediment accumulation in the pipe invert was daily measured. Within the 7–11 days, the average sediment accumulation rate found in the circular pipe was between 1.4 and 3.8 mm/d. The sediment height depended on the input wastewater sediment distribution and organic content. The egg-shaped pipe presented no sediment deposit for the same downstream boundary conditions, although biofilms were attached to the walls of both pipes. Besides, wastewater quality was monitored continuously and sediment composition was studied at the end of experiments. Two types of sediment were recorded: a granular bed deposit (ρ = 1,460 kg/m3, d50 = 202 μm) and wall biofilms (ρ = 1,190 kg/m3, d50 = 76 μm).

scholarly journals Influence of moisture content on estimating Young’s modulus of full-scale timber using stress wave velocity

2017 ◽  
Vol 63 (3) ◽  
pp. 225-235 ◽  
Author(s):  
Mariko Yamasaki ◽  
Chika Tsuzuki ◽  
Yasutoshi Sasaki ◽  
Yuji Onishi
Keyword(s):  
Moisture Content ◽  
Young’S Modulus ◽  
Wave Velocity ◽  
Stress Wave ◽  
Young's Modulus ◽  
Full Scale ◽  
Stress Wave Velocity
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