Małgorzata Kacprzak

Sewage sludge disposal strategies for sustainable development

ABSTRACT The main objective of the present review is to compare the existing sewage sludge management solutions in terms of their environmental sustainability. The most commonly used strategies, that include treatment and disposal has been favored within the present state‐of‐art, considering existing legislation (at European and national level), characterization, ecotoxicology, waste management and actual routs used currently in particular European countries. Selected decision making tools, namely End‐of‐waste criteria and Life Cycle Assessment has been proposed in order to appropriately assess the possible environmental, economic and technical evaluation of different systems. Therefore, some basic criteria for the best suitable option selection has been described, in the circular economy “from waste to resources” sense. The importance of sewage sludge as a valuable source of matter and energy has been appreciated, as well as a potential risk related to the application of those strategies. HighlightsEnvironmental sustainability in sewage sludge management.Investigation of eco‐innovations in wastewater treatment.Assessment of ecological consequences of sewage sludge disposal.

Improving the phytoremediation of heavy metals contaminated soil by use of sewage sludge

ABSTRACT Sewage sludge, in particular from the food industry, is characterized by fertilizing properties, due to the high content of organic matter and nutrients. The application of sewage sludge causes an improvement of soil parameters as well as increase in cation exchange capacity, and thus stronger binding of cations in the soil environment, which involves the immobilization of nutrients and greater resistance to contamination. In a field experiment sewage sludge has been used as an additive to the soil supporting the phytoremediation process of land contaminated with heavy metals (Cd, Zn, and Pb) using trees species: Scots pine (Pinus silvestris L.), Norway spruce (Picea abies L.), and oak (Quercus robur L.). The aim of the research was to determine how the application of sewage sludge into the soil surface improves the phytoremediation process. The conducted field experiment demonstrated that selected trees like Scots pine and Norway spruce, because of its excellent adaptability, can be used in the remediation of soil. Oak should not be used in the phytoremediation process of soils contaminated with high concentrations of trace elements in the soil, because a significant amount of heavy metals was accumulated in the leaves of oak causing a risk of recontamination.

The presence of contaminations in sewage sludge – The current situation

Abstract Sewage sludge/biosolids are by-wastes of municipal and industrial wastewater treatment. As sources of nutrients (C, N, P) they are widely used in intensive farming where large supplementation of organic matter to maintain fertility and enhance crop yields is needed. However, according to the report of European Commission published in 2010, only 39% of produced sewage sludge is recycled into agriculture in the European Union. This situation occurs mainly due to the fact, that the sewage sludge may contain a dangerous volume of different contaminants. For over decades, a great deal of attention has been focused on total concentration of few heavy metals and pathogenic bacteria Salmonella and Escherichia coli. The Sewage Sludge Directive (86/278/EEC) regulates the allowable limits of Zn, Cu, Ni, Pb, Cd, Cr and Hg and pathogens and allows for recovery of sludge on land under defined sanitary and environmentally sound conditions. In this paper, a review on quality of sewage sludge based on the publications after 2010 has been presented. Nowadays there are several papers focusing on new serious threats to human health and ecosystem occurring in sewage sludge – both chemicals (such as toxic trace elements – Se, Ag, Ti; nanoparticles; polyaromatic hydrocarbons; polychlorinated biphenyl; perfluorinated surfactants, polycyclic musks, siloxanes, pesticides, phenols, sweeteners, personal care products, pharmaceuticals, benzotriazoles) and biological traits (Legionella, Yersinia, Escherichia coli O157:H7).

Human-virulent microsporidian spores in solid waste landfill leachate and sewage sludge, and effects of sanitization treatments on their inactivation

Solid waste landfill leachate and sewage sludge samples were quantitatively tested for viable Enterocytozoon bieneusi, Encephalitozoon intestinalis, Encephalitozoon hellem, and Encephalitozoon cuniculi spores by the multiplexed fluorescence in situ hybridization (FISH) assay. The landfill leachate samples tested positive for E. bieneusi and the sludge samples for E. bieneusi and E. intestinalis. The effects of four sanitization treatments on the inactivation of these pathogens were assessed. Depending on the variations utilized in the ultrasound disintegration, sonication reduced the load of human-virulent microsporidian spores to nondetectable levels in 19 out of 27 samples (70.4%). Quicklime stabilization was 100% effective, whereas microwave energy disintegration was 100% ineffective against the spores of E. bieneusi and E. intestinalis. Top-soil stabilization treatment gradually reduced the load of both pathogens, consistent with the serial dilution of sewage sludge with the soil substrate. This study demonstrated that sewage sludge and landfill leachate contained high numbers of viable, human-virulent microsporidian spores, and that sonication and quicklime stabilization were the most effective treatments for the sanitization of sewage sludge and solid waste landfill leachates. Multiplexed FISH assay is a reliable quantitative molecular fluorescence microscopy method for the simultaneous identification of E. bieneusi, E. intestinalis, E. hellem, and E. cuniculi spores in environmental samples.

Efficacy of Biosolids in Assisted Phytostabilization of Metalliferous Acidic Sandy Soils with Five Grass Species

The role of sewage sludge as an immobilising agent in the phytostabilization of metal-contaminated soil was evaluated using five grass species viz., Dactylis glomerata L., Festuca arundinacea Schreb., F. rubra L., Lolium perenne L., L. westerwoldicum L. The function of metal immobilization was investigated by monitoring pH, Eh and Cd, Pb, and Zn levels in column experiment over a period of 5-months. Grasses grown on sewage sludge-amendments produced high biomass in comparison to controls. A significant reduction in metal uptake by plants was also observed as a result of sewage sludge application, which was attributed to decreased bioavailability through soil stabilisation. We have observed that the sludge amendment decreased metal bioavailability and concentrations in soil at a depth of 25 cm, in contrast to untreated columns, where metal concentrations in the soil solution were very high.

Determination of the performance of vermicomposting process applied to sewage sludge by monitoring of the compost quality and immune responses in three earthworm species: Eisenia fetida, Eisenia andrei and Dendrobaena veneta

The aim of this study was to assess the effectiveness of vermicomposting process applied on three different sewage sludge (precomposted with grass clippings, sawdust and municipal solid wastes) using three different earthworm species. Selected immune parameters, namely biomarkers of stress and metal body burdens, have been used to biomonitor the vermicomposting process and to assess the impact of contaminants on earthworms physiology. Biotic and abiotic parameters were also used in order to monitor the process and the quality of the final product. Dendrobaena veneta exhibited much lower resistance in all experimental conditions, as the bodyweight and the total number of circulating immune cells decreased in the most contaminated conditions. All earthworm species accumulated heavy metals as follows Cd>Co>Cu>Zn>Ni>Pb>Cr: Eisenia sp. worms exhibited the highest ability to accumulate several heavy metals. Vermicompost obtained after 45days was acceptable according to agronomic parameters and to compost quality norms in France and Poland.

The Effect of Trichoderma on Heavy Metal Mobility and Uptake by Miscanthus giganteus, Salix sp., Phalaris arundinacea, and Panicum virgatum

The effect of land application of biomaterials based on two strains of Trichoderma fungus on phytoremediation processes was studied. Six metals (Cd, Cr, Cu, Pb, Zn, and Ni) were analysed in soil and soil leachate as well as in plant tissues. The translocation index () and metal bioconcentration factors (BCF) calculated for the inoculated plants were increased compared to the noninoculated control, except for Pb and Salix sp. Simultaneously, the mobilisation of metals in soil solution as an effect of biomaterials was noted. The highest values of —339% (for Cr), 190% (for Ni), and 110% (for Cu)—were achieved for the combination Miscanteus giganteus and Trichoderma MSO1. The results indicated that the application of fungus has positive effects on increasing the biomass, soil parameters (C, N, and P), and solubility of heavy metals in soil and therefore in enhancing phytoextraction for Miscanthus giganteus L., Panicum virgatum L., Phalaris arundinacea L., and Salix sp.

Anaerobic digestion of sewage sludge with grease trap sludge and municipal solid waste as co-substrates ☆

&NA; The feasibility of simultaneous treatment of multiple wastes via co‐digestion was studied in semi‐continuous mode at mesophilic conditions. The obtained results indicated that sewage sludge, organic fraction of municipal waste (OFMSW) and grease trap sludge (GTS) possess complementary properties that can be combined for successful anaerobic digestion. During the co‐digestion period, methane yield and VS removal were significantly higher in comparison to digestion of sewage sludge alone. Addition of GTS to digesters treating sewage sludge resulted in increased VS removal and methane yield up to 13% (from 50 to 56.4) and 52% (from 300 to 456,547 m3/Mg VSadd), respectively. While the use of OFMSW as the next co‐substrate in the feedstock, can boost methane yield and VS removal up to 82% (300–547 m3/Mg VSadd) and approximately 29% (from 50% to 64.7%), respectively. Moreover, the results of the present laboratory study revealed that the addition of co‐substrates to the feedstock had a significant influence on biogas composition. During the experiment methane content in biogas ranged from 67% to 69%. While, the concentration of LCFAs was increasing with the gradual increase in the share of co‐substrates in the mixtures, wherein only the oleic acid was higher than some inhibition concentrations which have been reported in the literature. However, it did not significantly affect the efficiency of the co‐digestion process. HighlightsAddition of two waste into the sewage sludge digester improves process efficiency.Co‐digestion of 3‐component mixtures increases VS removal up to 29%.While, methane yield increased up to and 82% relative to the control digester.Effectiveness of the process depends on OLR and the content of waste in the feedstock.

Occurrence changes of Escherichia coli (including O157:H7 serotype) in wastewater and sewage sludge by quantitation method of (EMA) real time—PCR

AbstractThere are hundreds of Escherichia coli serotypes and among them enterohaemorrhagic strain E. coli O157:H7 causing gastrointestinal disorders such as: bloody diarrhea, cramping and abdominal pain and the infectious “hemolytic uremic syndrome”. Therefore, it’s important to develop some rapid and reliable methods of detecting this pathogen in wastewater and sewage sludge. This will allow one to determine the potential risk of infection for humans and animals as far as wastewater and sewage management is concerned. E. coli non- and -O157:H7 gene copies were detected in primary influents and final effluents in winter from municipal wastewater treatment plant. The ethidium monoazide bromide (EMA) application revealed false-positive detection of this bacteria in final effluents. In spring and summer, E. coli gene was not found either in wastewater or in sludge. In autumn, E. coli genes were found in primary influents (20,000 copies of gene/100 mL) and final effluents (2,511 copies of gene/100 mL). High a...

The evaluation of polycyclic aromatic hydrocarbons (PAHs) biodegradation kinetics in soil amended with organic fertilizers and bulking agents

The aim of this study was to investigate the polycyclic aromatic hydrocarbons (PAHs) biodegradation kinetics in soils fertilized with organic amendments (sewage sludge, compost), bulking agents (mineral sorbent, silicon dioxide in form of nano powder), and novel compositions of those materials. The scope of conducted works includes a cyclic CO2 production measurements and the determinations of PAHs content in soil samples, before and after 3-months of incubation. Obtained results show that the use of both type of organic fertilizers have a positive effect on the PAHs removal from soil. However, the CO2 emission remains higher only in the first stage of the process. The best acquired means in terms of PAHs removal as well as most sustained CO2 production were noted in samples treated with the mixtures of organic fertilizers and bulking agents. In conclusion the addition of structural forming materials to the organic fertilizers was critical for the soil bioremediation efficiency. Therefore, the practical implementation of collected data could find a wide range of applications during the design of new, more effective solutions for the soil bioremediation purposes.