The use of sewage sludge in the production of ceramic floor tiles

Abstract

Scientists proved that municipal sewage sludge contains many dangerous pathogens, toxic heavy metals, endocrine disruptors, drains, storm water runoff, hospitals, and industrial plants. Sewage sludge represents an extremely high ecological hazard to the environment. Due to the increasing amount of sludge generated from the wastewater treatments plants a strong demand for environmentally and effective safe reuse has arisen. One potential use of that waste is its incorporation in the production of ceramic tiles. The main aim of present work was to study the possibility of usage of this hazardous waste in floor ceramic tiles industry. A dried sludge waste was added in percentages from 5% up to 35% to a standard floor tile mix, molded, pressed uniaxially at 30 MPa and then fired at temperatures reaching 1150°C for 15 min soaking time. The properties of both green and fired tiles were investigated as function of percent waste added. The vitrification parameters, which are linear firing shrinkage, water absorption, apparent porosity, and mechanical property, were determined and compared with ISO standards. Fired samples of the proposed mixtures were investigated by scanning electron microscope (SEM). It was possible to obtain tiles that abided by ISO standards for maximum addition of 7% sludge fired at 1150°C (for water absorption < 10%), and 10% sludge or 5% sludge for tiles fired at 1150°C and 1100°C, respectively (for water absorption > 10%), which are recommended for both their economic and environmental benefits.

Effect of use residual sludge from watertreatment plants as a partial substitute forclay for refractory bricks production

“…The mineralogical composition of both sludge: LPTAI and LPTAP, indicate the majority presence of quartz (40-50%), with presence of kaolinite, moscovite and albite phases; which coincides with the mineralogical characterizations reported in the literature [25,28,29]. It is interesting to highlight the presence of the nacrite phase in the mineralogy result in table 2, this phase is associated with the mineral group of the phyllosilicates (serpentines), which has not been mentioned in previous works reported in the region.…”

“…Other studies, as [25] evaluated the use of sewage sludge in the production of ceramic floor tiles, obtaining that was possible to produce tiles that abided by ISO standards for water absorption <10% with a maximum addition of 7% sludge, fired at 1150 °C; while additions of 5-10% sludge, fired at 1100 °C and 1150 °C, respectively, increased water absorption to more than 10%.…”

Potencial De Aprovechamiento De Lodos Industriales en La Fabricación De Pegante Cerámico Gris Para Pisos

“…The municipal sludges of the WWTP are mostly composed of organic matter, silicon oxides and aluminum oxides, which is consistent with what was reported by Amin (11) that found that the municipal sludge generated in Cairo, Egypto had a content high organic matter according to reports of losses due to ignition (65%). It should be noted that the reports of specific FRX results for industrial sludge of different productive activities linked to this research are limited, which is why the results of the most documented industries were contrasted, in this case it was the metalworking or also called galvanic productive sector.…”

Recycling of glass waste in ceramics—part I: physical, mechanical and thermal properties

“…The increase in the various solid waste residues in the cities particularly those do not decompose easily neither in nature, nor by weathering factors for thousands of years such as wastes of glass bottle that created the growth of both ground and air populations. The recycling of these wastes is an important environmental and economical alternative solution [3][4][5][6][7][8][9][10][11][12]. This will make that it is possible to reach some important objectives related to the storage of wastes, conserving limited supplies of natural raw materials and consequently, safeguarding the environment [3,4].…”