Effect of High Strength Food Wastes on Anaerobic Co-digestion of Sewage Sludge

Chemical, physical, morphological, and mineralogical analysis of sewage sludge originating from a waste water treatment plant in Patras, Greece, is presented in the paper. The sewage sludge is firstly dried at 70°C, then oven-burned at 700°C for two hours and milled. The thermally treated material is analyzed using XRF and XRD, the particle size distribution is determined by a laser diffraction method. A potential use of sewage sludge in blended cements is investigated on the basis of the measurement of mechanical and basic physical properties of pastes containing the sludge in an amount of up to 60% of the mass of cement. Experimental results show that the thermal treatment of pre-dried sewage sludge and its grinding provides a material that can be successfully applied as a partial replacement of Portland cement. At a production of blended cements for high strength concrete, an up to 20% cement replacement level can be recommended.

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Biotechnology of intensive aerobic conversion of sewage sludge and food waste into fertilizer

Water Science & Technology ◽

10.2166/wst.2004.0631 ◽

2004 ◽

Vol 49 (10) ◽

pp. 147-154 ◽

Cited By ~ 8

Author(s):

J.-Y. Wang ◽

O. Stabnikova ◽

S.T.-L. Tay ◽

V. Ivanov ◽

J.-H. Tay

Keyword(s):

Sewage Sludge ◽

Organic Carbon ◽

Food Waste ◽

Bacterial Culture ◽

Food Wastes ◽

Coenzyme F420 ◽

Plant Seeds ◽

Volatile Solids ◽

Anaerobic Biomass ◽

Closed Reactor

Biotechnology for intensive aerobic bioconversion of sewage sludge and food waste into fertilizer was developed. The wastes were treated in a closed reactor under controlled aeration, stirring, pH, and temperature at 60¡C, after addition of starter bacterial culture Bacillus thermoamylovorans. The biodegradation of sewage sludge was studied by decrease of volatile solids (VS), content of organic carbon and autofluorescence of coenzyme F420. The degradation of anaerobic biomass was faster than biodegradation of total organic matter. The best fertilizer was obtained when sewage sludge was thermally pre-treated, mixed with food waste, chalk, and artificial bulking agent. The content of volatile solid and the content of organic carbon decreased at 24.8% and 13.5% of total solids, respectively, during ten days of bioconversion. The fertilizer was a powder with moisture content of 5%. It was stable, and not toxic for the germination of plant seeds. Addition of 1.0 to 1.5% of this fertilizer to the subsoil increased the growth of different plants tested by 113 to 164%. The biotechnology can be applied in larger scale for the recycling of sewage sludge and food wastes in Singapore.

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Production of High Performance Haydite from Sewage Sludge

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.113-116.1097 ◽

2010 ◽

Vol 113-116 ◽

pp. 1097-1100

Author(s):

Zhen Wen Zhang ◽

Jun Zhe Liu ◽

Zhi Min He ◽

Hai Hua Zhou

Keyword(s):

Sewage Sludge ◽

Water Absorption ◽

Metal Content ◽

High Performance ◽

High Strength ◽

Microstructure Analysis ◽

Preheat Temperature ◽

Optimum Parameters ◽

Particle Strength ◽

Leaching Procedure

Using sewage sludge to manufacture green high performance haydite was investigated. Sewage sludge was blended with fly ash and river silt, made into raw haydite pellets and sintered. The haydite properties of different mix proportions and sinter parameters were studied. Then microstructure analysis and toxicity characteristic leaching procedure (TCLP) were performed. Results show that reducing sludge percentage of raw pellets decreases water absorption, also makes particle strength and apparent density raise. Increasing preheat temperature enhances particle strength and density while reduces water absorption. Sintered with optimum parameters, density grade of sludge haydite is 700, water absorption is 0.6%, and cylinder compressive strength is 6.6MPa. Microstructure analysis shows enamel surface and internal fine porous structure make haydite lightweight, high strength and low water absorption. And TCLP results show traces of heavy metal content are found in sludge haydite.

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Food wastes and sewage sludge as feedstock for an urban biorefinery producing biofuels and added‐value bioproducts

Journal of Chemical Technology & Biotechnology ◽

10.1002/jctb.6096 ◽

2019 ◽

Vol 95 (2) ◽

pp. 328-338 ◽

Cited By ~ 18

Author(s):

Federico Battista ◽

Nicola Frison ◽

Paolo Pavan ◽

Cristina Cavinato ◽

Marco Gottardo ◽

...

Keyword(s):

Sewage Sludge ◽

Added Value ◽

Food Wastes

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Sludge Melting Process with Hazardous Asbestos Wastes

Water Science & Technology ◽

10.2166/wst.1991.0659 ◽

1991 ◽

Vol 23 (10-12) ◽

pp. 2029-2037 ◽

Cited By ~ 3

Author(s):

S. Sakai ◽

H. Takatsuki ◽

M. Hiraoka ◽

T. Tsunemi

Keyword(s):

Sewage Sludge ◽

Construction Materials ◽

High Strength ◽

Melting Process ◽

Melting Behavior ◽

X Ray Diffraction ◽

Asbestos Cement ◽

Plant Experiment ◽

By Products ◽

Temperature Melting

Sewage sludge melting has been developed and operated in full-scale plants for sludge processing and utilization of the by-products as construction materials. Hazardous asbestos wastes should be disposed of properly so not to lead to environmental pollution. The co-melting process for sewage sludge and asbestos wastes is discussed based on the basic melting behavior of asbestos and the laboratory plant experiment. Microscopic observation and X-ray diffraction analysis showed that asbestos forms could be changed physically and chemically by the high temperature melting. The disappearance of asbestos fibrous forms and chemical changes of its composition in the melted slag are not always concluded to be non-toxic, but considering that the melted slag is a rock-like material with high strength, the melting is acceptable as a method of hazardous asbestos waste disposal. Laboratory scale experiments have been conducted on co-melting disposal of sprayed-on chrysotile asbestos waste and a mixture of lime-added and polymer-added sewage sludge. It was possible to maintain the temperatures around 1600 °C and to discharge slag smoothly. It is also expected that asbestos cement wastes will contribute to the adjustment materials of basicity (CaO/SiO2) in the polymer-added sludge melting.

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