Extraction and Purification of Phosphorus from the Ashes of Incinerated Biological Sewage Sludge

Phosphorus depletion represents a significant problem. Ash of incinerated biological sewage sludge (BSS) contains P, but the presence of heavy metals (e.g., Fe and Al) is the main issue. Based on chemical characterization by SEM-EDS, ED-XRF and ICP-OES techniques, the characteristics and P content of bottom ash (BA) and fly ash (FA) of incinerated BSS were very similar. On BA, P extraction carried out in counter- current with an S:L ratio of 1:10 and H2SO4 0.5 M led to better extraction yields than those of a similar test with H2SO4 1 M and an S:L ratio of 1:5 (93% vs. 86%). Comparing yields with H2SO4 0.5 M (S:L ratio of 1:10), the counter-current method gave better results than those of the crossflow method (93% vs. 83.9%), also improving the performance obtained with HCl in crossflow (93% vs. 89.3%). The results suggest that the purification of the acid extract from heavy metals with pH variation was impractical due to metal precipitation as phosphates. Extraction with H2SO4 and subsequent treatment with isoamyl alcohol represented the best option to extract and purify P, leading to 81% extraction yields of P with low amounts of metals.

Download Full-text

PHYSICAL-CHEMICAL CHARACTERIZATION OF SOILS TREATED WITH SEWAGE SLUDGE COMPOST

Mokslas - Lietuvos ateitis ◽

10.3846/mla.2010.097 ◽

2010 ◽

Vol 2 (5) ◽

pp. 87-92

Author(s):

Milda Radžiūtė ◽

Audronė Matusevičiūtė

Keyword(s):

Heavy Metals ◽

Water Treatment ◽

Sewage Sludge ◽

Organic Waste ◽

Organic Fertilizer ◽

Chemical Characterization ◽

Waste Dump ◽

Sludge Compost ◽

Sewage Sludge Compost

Sewage dump is the main organic waste component accumulating in water treatment companies, and therefore the utilization of dump remains a burning issue. Fertilization is the most popular and cheapest way of using sewage dump a part of which is intended for agriculture in most European countries for composting purposes. Sewage dump or its compost are suitable for fertilizing the upper layers of the soil in cases the concentration of heavy metals is not greater than sanitarian standards can tolerate. The examinations were carried out using different waste dump rates from Vilnius water treatment facility in willow (Salix viminalis) grown cultivated fields. The analysis of the soil was executed after one and two years following the fertilization process. The obtained results indicate that waste dump is a valuable organic fertilizer which contains small amounts of heavy metals. Separate heavy metals migrate from sewage sludge compost to plants differently. It was noted that the concentration of heavy metals in willows was greater (except for Pb and Cd) than that in the soil.

Download Full-text

Stabilization of Municipal Solid Waste Fly Ash, Obtained by Co-Combustion with Sewage Sludge, Mixed with Bottom Ash Derived by the Same Plant

Applied Sciences ◽

10.3390/app10176075 ◽

2020 ◽

Vol 10 (17) ◽

pp. 6075

Author(s):

Ahmad Assi ◽

Fabjola Bilo ◽

Alessandra Zanoletti ◽

Laura Borgese ◽

Laura Eleonora Depero ◽

...

Keyword(s):

Heavy Metals ◽

Fly Ash ◽

Sewage Sludge ◽

Municipal Solid Waste ◽

Solid Waste ◽

Coal Fly Ash ◽

Bottom Ash ◽

Solid Material ◽

Flue Gas Desulfurization ◽

Stabilization Method

This study presents an innovative stabilization method of fly ash derived from co-combustion of municipal solid waste and sewage sludge. Bottom ash, obtained from the same process, is used as a stabilizing agent. The stabilization method involved the use of two other components—flue gas desulfurization residues and coal fly ash. Leaching tests were performed on stabilized samples, aged in a laboratory at different times. The results reveal the reduction of the concentrations of heavy metals, particularly Zn and Pb about two orders of magnitude lower with respect to fly ash. The immobilization of heavy metals on the solid material mainly depends on three factors—the amount of used ash, the concentrations of Zn and Pb in as-received fly ash and the pH of the solution of the final materials. The inert powder, obtained after the stabilization, is a new eco-material, that is promising to be used as filler in new sustainable composite materials.

Download Full-text

EXTRACTION OF HEAVY METALS IN A SEWAGE SLUDGE-TREATED LATOSOL

Southern Brazilian Journal of Chemistry - Southern Brazilian Journal of Chemistry, Volume 28, No. 28, 2020 ◽

10.48141/sbjchem.v13.n13.2005.17_2005.pdf ◽

2005 ◽

Vol 13 (13) ◽

pp. 13-25

Author(s):

Ana Tereza Jordao Pigozzo ◽

Jorge De Lucas Jr ◽

Ervim Lenzi ◽

Carlos Alberto Scapim ◽

Antonio Carlos Saraiva da Costa

Keyword(s):

Heavy Metals ◽

Sewage Sludge ◽

Exchange Capacity ◽

Soil Samples ◽

First Year ◽

Fertility Level ◽

Ph Variation ◽

Initial Ph ◽

Second Year ◽

Different Doses

The presence of heavy metals is one of the main hazards against the use of sewage sludge in agronomy. In a field experiment applications of sewage sludge in medium-textured Dark Red Latisol (DRL) were evaluated by the extraction of essential or non-essential metals with a DTPA extractor. The experimental design consisted of randomized blocks subdivided into sections of 6 treatments of sewage sludge (0, 6, 20, 40, 60 and 80 t ha-1) during the first year and (0, 6, 20, 40, 60 and 80 t ha-1) during the second year. The experiment had 4 replications and 5 soil collection periods (0, 30, 60, 90, and 120 days of sludge incorporation). Sewage sludge was applied at a mean depth of 0-20 cm. Soil sampling was undertaken during the periods of sludge incorporation so that the elements available in the soil in different doses could be evaluated Soil samples were analyzed as to fertility level. Concentrations of the metals Cu, Zn, Cd, Ni, Co, Pb, and Cr were determined by atomic absorption in DTPA extractor solution. Concentrations of Cd, Ni, Co, Pb, and Cr were not detected since values were lower than the detection limit of each. Application of sewage sludge increased Cation Exchange Capacity (CEC) and there was an initial pH variation, albeit the latter returned concentration to its original level. Owing to the repetition of applied sludge, Cu and Zn rates in soil samples gradually increased during the two agricultural years caused by an increase in the doses of applied sewage sludge.

Download Full-text

Sewage Sludge Bottom Ash Characteristics and Potential Application in Road Embankment

Sustainability ◽

10.3390/su12010039 ◽

2019 ◽

Vol 12 (1) ◽

pp. 39 ◽

Cited By ~ 1

Author(s):

Katarzyna Zabielska-Adamska

Keyword(s):

Heavy Metals ◽

Sewage Sludge ◽

Bottom Ash ◽

Construction Materials ◽

Municipal Sewage ◽

Municipal Sewage Sludge ◽

Natural Soil ◽

Incineration Plant ◽

Heavy Metal Concentrations ◽

Soil Solutions

The paper focuses on sustainability-related applications in civil engineering by using environmentally friendly, alternative construction materials. The paper presents geotechnical properties of thermally converted, municipal sewage sludge in a grate furnace in an incineration plant. Bottom ash and its mixture with sand have been tested to show that they can be considered as a substitute for natural soil built-in road embankments. The product of sewage sludge combustion and its combination with sand meet all code requirements for material suitable for road embankments. As a result of the 30% reduction of resistance to failure values after waste soaking, which causes relatively low California Bearing Ratio (CBR) values of soaked waste, waste should be built into places isolated from groundwater and precipitation. That is also indicated by the possibility of heavy metals leaching from the waste because such content is much higher than in uncontaminated soils, although leaching does not exceed the limits commonly quoted for natural soil solutions. Tested bottom ash as a product of combustion in a grate furnace is a more preferred material for earthworks than fly ash generated during incineration in a furnace with fluidized bed due to the particle size and heavy metal concentrations.

Download Full-text

Effect of Composted Sewage Sludge on Metals Leaching Behavior in Municipal Solid Waste Incineration Bottom Ash

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.295-298.418 ◽

2013 ◽

Vol 295-298 ◽

pp. 418-421

Author(s):

Hai Xia Zhang ◽

Takayuki Shimaoka

Keyword(s):

Heavy Metals ◽

Organic Matter ◽

Sewage Sludge ◽

Municipal Solid Waste ◽

Solid Waste ◽

Bottom Ash ◽

Waste Incineration ◽

Municipal Solid Waste Incineration ◽

Mswi Bottom Ash ◽

Composted Sewage Sludge

In order to study the effect of organic matter on the heavy metals leachability from municipal solid waste incineration (MSWI) bottom ash. In the project, the composted sewage sludge (CS) rich in organic matter was mixed with MSWI bottom ash in a certain proportion. e exudation test, determination of the leaching liquid pH, dissolved organic carbon and humus concentration, and the concentration of heavy metals. And the combination of CS and BA in organic compounds and metal content, calculate metal leaching rate. According to the experimental results, analysis of dissolved organic matter and humic acid concentrations and Cu and Cr leaching concentration, showed that when CS mixture ratio of 20%, organic matter and humic substances concentration and Cu and Cr leaching concentrations are highly linear correlation.

Download Full-text

Combustion Melting Characterisation of Solid Fuel Obtained from Sewage Sludge

Energies ◽

10.3390/en14040805 ◽

2021 ◽

Vol 14 (4) ◽

pp. 805

Author(s):

Dongju Kim ◽

Dong-kyoo Park ◽

Yong-taek Lim ◽

Soo-nam Park ◽

Yeong-Su Park ◽

...

Keyword(s):

Heavy Metals ◽

Sewage Sludge ◽

Solid Fuel ◽

Bottom Ash ◽

Gas Analysis ◽

Fuel Pellet ◽

Heating Value ◽

Plant Experiment ◽

Measurement Experiment ◽

Metal Elution

Solid fuelization technology can increase the heating value of sewage sludge such that it can be utilised as a fossil fuel substitutes. Reducing landfilling of bottom and fly ash resulting from heavy metals contained in sewage sludge is challenging. Hence, combustion melting technology (CMT), which can discharge bottom ash in the form of slag, has been proposed herein as an alternative to the conventional incineration technology. However, further research is required to improve the flowability of slag. Applicability of CMT for the stable treatment of heavy metals in the ash generated during the energisation of sewage sludge solid fuel has been reviewed. The change in the degree of fluidity was identified via a laboratory-scale fluidity measurement experiment following changes in melting temperature, mixing ratio of sewage sludge and sawdust, and basicity. The pouring index (PI) of sewage sludge solid fuel (pellet) was maintained at a level of about 60% at a basicity index of 0.8. Based on the results, the slagging rates and volume reduction rates, exhaust gas analysis, and heavy metal elution characteristics under oxygen enrichment were derived from a 2 ton/day combustion melting pilot plant experiment; thereafter, the feasibility of combustion melting of sewage sludge solid fuel was determined.

Download Full-text

Co-Combustion of Municipal Sewage Sludge and Biomass in a Grate Fired Boiler for Phosphorus Recovery in Bottom Ash

Energies ◽

10.3390/en13071708 ◽

2020 ◽

Vol 13 (7) ◽

pp. 1708 ◽

Cited By ~ 2

Author(s):

Andreas Nordin ◽

Anna Strandberg ◽

Sana Elbashir ◽

Lars-Erik Åmand ◽

Nils Skoglund ◽

...

Keyword(s):

Heavy Metals ◽

European Union ◽

Sewage Sludge ◽

Fixed Bed ◽

Bottom Ash ◽

Phosphorus Recovery ◽

Fixed Bed Reactor ◽

Municipal Sewage ◽

Municipal Sewage Sludge ◽

Critical Element

Phosphorus has been identified as a critical element by the European Union and recycling efforts are increasingly common. An important phosphorus-containing waste stream for recycling is municipal sewage sludge (MSS), which is used directly as fertilizer to farmland. However, it contains pollutants such as heavy metals, pharmaceutical residues, polychlorinated bi-phenyls (PCBs) and nano-plastics. The interest in combustion of MSS is continuously growing, as it both reduces the volume as well as destroys the organic materials and could separate certain heavy metals from the produced ashes. This results in ashes with a potential for either direct use as fertilizer or as a suitable feedstock for upgrading processes. The aim of this study was to investigate co-combustion of MSS and biomass to create a phosphorus-rich bottom ash with a low heavy metal content. A laboratory-scale fixed-bed reactor in addition to an 8 MWth grate-boiler was used for the experimental work. The concentration of phosphorus and selected heavy metals in the bottom ashes were compared to European Union regulation on fertilizers, ash application to Swedish forests and Swedish regulations on sewage sludge application to farmland. Element concentrations were determined by ICP-AES complemented by analysis of spatial distribution with SEM-EDS and XRD analysis to determine crystalline compounds. The results show that most of the phosphorus was retained in the bottom ash, corresponding to 9–16 wt.% P2O5, while the concentration of cadmium, mercury, lead and zinc was below the limits of the regulations. However, copper, chromium and nickel concentrations exceeded these standards.

Download Full-text