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Mazzeo DEC, Dombrowski A, Oliveira FA, Levy CE, Oehlmann J, Marchi MRR. Endocrine disrupting activity in sewage sludge: Screening method, microbial succession and cost-effective strategy for detoxification. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 330:117207. [PMID: 36621316 DOI: 10.1016/j.jenvman.2022.117207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 12/19/2022] [Accepted: 12/31/2022] [Indexed: 06/17/2023]
Abstract
Sewage sludge (SS) presents a high agronomic potential due to high concentrations of organic matter and nutrients, encouraging its recycling as a soil conditioner. However, the presence of toxic substances can preclude this use. To enable the safe disposal of this waste in agriculture, SS requires additional detoxification to decrease the environmental risks of this practice. Although some alternatives have been proposed in this sense, little attention is provided to eliminating endocrine-disrupting chemicals (EDCs). To fill this gap, this study aimed to develop effective and low-cost technology to eliminate EDCs from SS. For this, a detoxification process combining microorganisms and biostimulating agents (soil, sugarcane bagasse, and coffee grounds) was performed for 2, 4, and 6 months with aerobic and anaerobic SSs. The (anti-)estrogenic, (anti-)androgenic, retinoic-like, and dioxin-like activities of SSs samples were verified using yeast-based reporter-gene assays to prove the effectiveness of the treatments. A fractionation procedure of samples, dividing the target sample extract into several fractions according to their polarity, was conducted to decrease the matrix complexity and facilitate the identification of EDCs. A decrease in the abundance and microbial diversity of the SS samples was noted along the biostimulation with the predominance of filamentous fungal species over yeasts and gram-positive bacteria and non-fermenting rods over enterobacteria. Among the 9 EDCs quantified by LC-ESI-MS/MS, triclosan and alkylphenols presented the highest concentrations in both SS. Before detoxification, the studied SSs induced significant agonistic activity, especially at the human estrogen receptor α (hERα) and the human aryl hydrocarbon receptor (AhR). The raw anaerobic sludge also activated the androgen (hAR), retinoic acid (RARα), and retinoid X (RXRα) receptors. However, no significant endocrine-disrupting activities were observed after the SS detoxification, showing that the technology applied here efficiently eliminates receptor-mediated toxicity.
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Affiliation(s)
- Dânia Elisa C Mazzeo
- Department of Biotechnology and Plant and Animal Production, Center for Agricultural Sciences, Federal University of São Carlos - UFSCAR, Araras, Brazil.
| | - Andrea Dombrowski
- Department Aquatic Ecotoxicology, Goethe University Frankfurt am Main, Germany
| | - Flávio Andrade Oliveira
- Department of Clinical Pathology, Faculty of Medical Sciences, State University of Campinas - UNICAMP, Rua Alexander Fleming, 105, 13081-970, Campinas, SP, Brazil
| | - Carlos Emílio Levy
- Department of Clinical Pathology, Faculty of Medical Sciences, State University of Campinas - UNICAMP, Rua Alexander Fleming, 105, 13081-970, Campinas, SP, Brazil
| | - Jörg Oehlmann
- Department Aquatic Ecotoxicology, Goethe University Frankfurt am Main, Germany
| | - Mary Rosa R Marchi
- Department of Analytical Chemistry, Institute of Chemistry, UNESP - Univ Estadual Paulista, Araraquara, SP, Brazil
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Santos T, Sommaggio LRD, Marin-Morales MA. Phyto-genotoxicity assessment of different associations between sludges from Water and Sewage Treatment Plants, before and after the bioremediation process. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:40029-40040. [PMID: 35118590 DOI: 10.1007/s11356-022-18820-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Accepted: 01/19/2022] [Indexed: 06/14/2023]
Abstract
Water Treatment Plants (WTP) and Sewage Treatment Plants (STP) generate residues known as sludge (WS and SS, respectively). SS and WS present some positive characteristics for reuse in agriculture. The aim of the present study was to evaluate, using the Allium cepa test, the effectiveness of the bioremediation process in the detoxification of SS and WS sludges. In this study, the phytotoxic, cytotoxic, genotoxic, and mutagenic potentials of pure sludge samples (WS and SS) were evaluated, as well as the association of these two sludges with soil (S), before and after the bioremediation process. In the T0 period (before undergoing bioremediation), the SS, SS + S, and SS + WS samples totally inhibited the germination of A. cepa, proving the high phytotoxic potential of these samples. For the T1 period (after 6 months of bioremediation), phytotoxicity was observed for the SS, SS + S, SS + WS, and SS + WS + S samples, but there was not a complete inhibition of germination and radicles growth, allowing the evaluation of the other parameters (cytogenotoxic and mutagenic potential). No cytotoxicity was observed for any sample, both in T0 and T1. As for the genotoxicity parameter, a significant result was observed for the pure WS sample in T0 and for all samples in T1, when compared to NC. The genotoxic alteration most found in meristematic cells exposed to treatments was of binucleated cells. Mutagenic potential was also observed for samples of WS and WS + S in T0. From this study, we can conclude that, after six months of bioremediation, despite the SS phytotoxicity being reduced, all samples were genotoxic to the A. cepa organism test.
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Affiliation(s)
- Tamara Santos
- Department of Biology, Institute of Biosciences, São Paulo State University (Unesp), Av. 24-A, Rio Claro, SP, 1515, 13506-900, Brazil
| | - Laís Roberta Deroldo Sommaggio
- Department of Biology, Institute of Biosciences, São Paulo State University (Unesp), Av. 24-A, Rio Claro, SP, 1515, 13506-900, Brazil
| | - Maria Aparecida Marin-Morales
- Department of Biology, Institute of Biosciences, São Paulo State University (Unesp), Av. 24-A, Rio Claro, SP, 1515, 13506-900, Brazil.
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Pantano G, Mazzeo DEC, Rocha THDS, Marin-Morales MA, Fadini PS, Mozeto AA. Toxicity of the sawdust used for phosphorus recovery in a eutrophic reservoir: experiments with Lactuca sativa and Allium cepa. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:18276-18283. [PMID: 33410013 DOI: 10.1007/s11356-020-11868-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Accepted: 11/29/2020] [Indexed: 06/12/2023]
Abstract
Eutrophication is one of the environmental problems arising from the increase of essential nutrient concentrations, mainly phosphorus and nitrogen. In contrast to excess phosphorus, the depletion of phosphate rock deposits used for the production of fertilizers compromises the food supply. Therefore, the development of technologies that propose the recovery of the phosphorus contained in eutrophic environments for its later use for agricultural fertilization purposes is very important to ensure global food security. This work aimed to evaluate the toxic potential of the sawdust (biosorbent previously used for phosphorus adsorption) in order to enable its application in agriculture. For this, toxicity experiments with Lactuca sativa (lettuce) and Allium cepa (onion) seeds were performed. The phytotoxic potential was assessed by means of the seed germination index and physiological parameters such as radicle and hypocotyl growth. Cytotoxicity, genotoxicity, and mutagenicity tests were also performed on onion seeds. From statistical tests, it was possible to affirm that the sawdust did not promote inhibition of seed germination and radicle and hypocotyl growth. No genotoxicity, cytotoxicity and, mutagenicity were observed, which allowed to state that the sawdust is not toxic to the onion species, which reinforces the possibility of application of the biosorbent for soil fertilization purposes. Therefore, the use of sawdust for phosphorus biosorption with the subsequent agricultural application is promising and quite important from a global food security point of view.
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Affiliation(s)
- Glaucia Pantano
- Departamento de Química, Universidade Federal do Paraná, Curitiba, Paraná, 81531-980, Brazil.
| | - Dânia Elisa Christofoletti Mazzeo
- Departamento de Bioquímica e Microbiologia, Instituto de Biociências, Universidade Estadual Paulista "Júlio de Mesquita Filho", Rio Claro, São Paulo, 13506-900, Brazil
| | - Thais Helena Dos Santos Rocha
- Laboratório de Biogeoquímica Ambiental - Núcleo de Estudos, Diagnósticos e Intervenções Ambientais, Departamento de Química, Universidade Federal de São Carlos, São Carlos, São Paulo, 13565-905, Brazil
| | - Maria Aparecida Marin-Morales
- Departamento de Biologia, Instituto de Biociências, Universidade Estadual Paulista "Júlio de Mesquita Filho", Rio Claro, São Paulo, 13506-900, Brazil
| | - Pedro Sergio Fadini
- Laboratório de Biogeoquímica Ambiental - Núcleo de Estudos, Diagnósticos e Intervenções Ambientais, Departamento de Química, Universidade Federal de São Carlos, São Carlos, São Paulo, 13565-905, Brazil
| | - Antonio Aparecido Mozeto
- Laboratório de Biogeoquímica Ambiental - Núcleo de Estudos, Diagnósticos e Intervenções Ambientais, Departamento de Química, Universidade Federal de São Carlos, São Carlos, São Paulo, 13565-905, Brazil
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Ahkola H, Lindholm-Lehto P, Perkola N, Välitalo P, Meriläinen P, Mäenpää K, Stelzer JAA, Heiskanen I, Järvistö J, Nuutinen J, Leppänen MT. A preliminary study on the ecotoxic potency of wastewater treatment plant sludge combining passive sampling and bioassays. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 758:143700. [PMID: 33257078 DOI: 10.1016/j.scitotenv.2020.143700] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 10/28/2020] [Accepted: 11/06/2020] [Indexed: 06/12/2023]
Abstract
Sewage sludge is an inevitable byproduct produced in wastewater treatment. Reusing nutrient-rich sludge will diminish the amount of waste ending in soil dumping areas and will promote circular economy. However, during sewage treatment process, several potentially harmful organic chemicals are retained in sludge, but proving the safety of processed sludge will promote its more extensive use in agriculture and landscaping. Environmental risk assessment of sludge requires new methods of characterizing its suitability for various circular economy applications. Bioavailable and bioaccessible fractions are key variables indicating leaching, transport, and bioaccumulation capacity. Also, sludge treatments have a significant effect on chemical status and resulting environmental risks. In this study, the concentrations of polyaromatic hydrocarbons (PAHs), triclosan (TCS), triclocarban (TCC), methyl triclosan (mTCS), and selected active pharmaceutical ingredients (APIs) were determined in different sludge treatments and fractions. Passive samplers were used to characterize the bioavailable and bioaccessible fractions, and the sampler extracts along the sludge and filtrate samples were utilized in the bioassays. The TCS and PAH concentrations did not decrease as the sludge was digested, but the contents diminished after composting. Also, mTCS concentration decreased after composting. The API concentrations were lower in digested sludge than in secondary sludge. Digested sludge was toxic for Aliivibrio fischeri, but after composting, toxicity was not observed. However, for Daphnia magna, passive sampler extracts of all sludge treatments were either acutely (immobility) or chronically (reproduction) toxic. Secondary and digested sludge sampler extracts were cytotoxic, and secondary sludge extract was also genotoxic. The measured chemical concentration levels did not explain the toxicity of the samples based on the reported toxicity thresholds. Bioassays and sampler extracts detecting bioavailable and bioaccessible contaminants in sludge are complementing tools for chemical analyses. Harmonization of these methodswill help establish scientifically sound regulative thresholds for the use of sludge in circular economy applications.
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Affiliation(s)
- Heidi Ahkola
- Finnish Environment Institute (SYKE), P.O.Box 140, FI-00251 Helsinki, Finland.
| | - Petra Lindholm-Lehto
- Aquatic Production Systems, Natural Resources Institute Finland (Luke), Survontie 9A, FI-40500 Jyväskylä, Finland; University of Jyväskylä, FI-40500 Jyväskylä, Finland
| | - Noora Perkola
- Finnish Environment Institute (SYKE), P.O.Box 140, FI-00251 Helsinki, Finland
| | - Pia Välitalo
- Finnish Environment Institute (SYKE), P.O.Box 140, FI-00251 Helsinki, Finland; Aalto University, Tietotie 1E, FI-02150 Espoo, Finland
| | - Päivi Meriläinen
- Finnish Environment Institute (SYKE), P.O.Box 140, FI-00251 Helsinki, Finland; Finnish Institute for Health and Welfare, P.O.Box 95, FI-70701 Kuopio, Finland
| | - Kimmo Mäenpää
- University of Eastern Finland, Yliopistokatu 2, P.O.Box 111, FI-80101 Joensuu, Finland
| | - Julio Alberto Alegre Stelzer
- Finnish Environment Institute (SYKE), P.O.Box 140, FI-00251 Helsinki, Finland; University of Geneva, CH-1211 Geneva, Switzerland
| | - Ilse Heiskanen
- Finnish Environment Institute (SYKE), P.O.Box 140, FI-00251 Helsinki, Finland
| | - Johanna Järvistö
- Finnish Environment Institute (SYKE), P.O.Box 140, FI-00251 Helsinki, Finland
| | - Jari Nuutinen
- Finnish Environment Institute (SYKE), P.O.Box 140, FI-00251 Helsinki, Finland
| | - Matti T Leppänen
- Finnish Environment Institute (SYKE), P.O.Box 140, FI-00251 Helsinki, Finland
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Mazzeo DEC, Misovic A, Oliveira FA, Levy CE, Oehlmann J, de Marchi MRR. Effects of biostimulation by sugarcane bagasse and coffee grounds on sewage sludges, focusing agricultural use: Microbial characterization, respirometric assessment and toxicity reduction. WASTE MANAGEMENT (NEW YORK, N.Y.) 2020; 118:110-121. [PMID: 32892088 DOI: 10.1016/j.wasman.2020.08.033] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2020] [Revised: 07/30/2020] [Accepted: 08/21/2020] [Indexed: 06/11/2023]
Abstract
Sewage sludge (SS) exhibits a relevant agronomic potential due to the high content of organic matter and nutrients. However, the presence of several toxic substances can prevent its agricultural application. This study evaluated if the incorporation of stimulating agents (coffee grounds and sugarcane bagasse) could contribute to an effective increase of the SS biodegradability in order to decrease its toxicity. The samples were prepared mixing aerobic or anaerobic sludge with soil, soil and bagasse, and soil and coffee grounds. Respirometric tests showed that stimulating agents enhanced the CO2 production. However, in terms of biodegradation efficiency, more satisfactory results were verified for the anaerobic SS, especially when mixed with coffee grounds. The biodegradation also favored the SS sanitization, eliminating the Enterobacteria. For baseline toxicity (Microtox with Aliivibrio fischeri) and phytotoxicity (Lactuca sativa), all the initial samples showed higher effects. Nevertheless, after the biodegradation, this toxicity was significantly decreased and the best results were obtained for the mixtures containing only soil and sludge. For the AREc32 assay (NRF2 mediated oxidative stress response), although a very weak response was observed, this effect was attenuated for the aerobic SS or completely eliminated for the anaerobic SS after the biodegradation. Thus, even though the use of biostimulation agents during the biodegradation led to an enhancement of microbial respiration, their incorporation to the samples do not seem to interfere in the decrease of the toxic potential of the studied SSs. However, the SS biodegradation in aerobiosis was crucial for toxicity reduction and to accelerate its maturity.
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Affiliation(s)
| | - Andrea Misovic
- Department Aquatic Ecotoxicology, Faculty of Biological Sciences, Goethe University Frankfurt am Main, Germany
| | - Flávio Andrade Oliveira
- Department of Clinical Pathology, Faculty of Medical Sciences, State University of Campinas - UNICAMP, Campinas, SP, Brazil
| | - Carlos Emílio Levy
- Department of Clinical Pathology, Faculty of Medical Sciences, State University of Campinas - UNICAMP, Campinas, SP, Brazil
| | - Jörg Oehlmann
- Department Aquatic Ecotoxicology, Faculty of Biological Sciences, Goethe University Frankfurt am Main, Germany
| | - Mary Rosa Rodrigues de Marchi
- Department of Analytical Chemistry, Institute of Chemistry, Universidade Estadual Paulista - UNESP, Araraquara, SP, Brazil
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Souza PMS, Sommaggio LRD, Marin-Morales MA, Morales AR. PBAT biodegradable mulch films: Study of ecotoxicological impacts using Allium cepa, Lactuca sativa and HepG2/C3A cell culture. CHEMOSPHERE 2020; 256:126985. [PMID: 32445994 DOI: 10.1016/j.chemosphere.2020.126985] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Revised: 05/01/2020] [Accepted: 05/04/2020] [Indexed: 05/06/2023]
Abstract
Biodegradable mulch films are an alternative to polyethylene films used in agriculture for weed control, improving crop productivity. This change could minimize the residue production and costs related to the final disposal. Nevertheless, the environmental safety of these biodegradable products is scarcely investigated. In this work, samples of poly(butylene adipate-co-terephthalate)-PBAT mulch films, with and without UV stabilizer additives, were prepared. Aqueous extracts of soil samples, where mulch films were disposed, were investigated using bioassays with Lactuca sativa, Allium cepa, and cell culture HepG2/C3A. As PBAT is expected to suffer photodegradation and biodegradation, soil samples mixed with films before and after these processes were evaluated. Soil aqueous extracts promoted root grown (mainly hypocotyl) of L. sativa, probably due to presence of nutrients. So, to evaluate toxicity potential, in this case it was necessary to use aqueous extract prepared with soil instead of ultrapure water as the control. After doing this analysis it was observed that no adverse impacts due to PBAT films occurred. No chromosomal abnormalities were observed in A. cepa bioassay for any of tested samples. The absence of genotoxic potential was confirmed by comet assay and micronucleus test using human hepatocarcinoma cell line HepG2/C3A. These results showed that the soil did not induce damage to the tested organisms, before and after degradation of PBAT films.
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Affiliation(s)
- Patrícia Moraes Sinohara Souza
- Department of Materials Engineering and Bioprocess, School of Chemical Engineering, State University of Campinas (UNICAMP), Campinas, SP, Brazil
| | | | | | - Ana Rita Morales
- Department of Materials Engineering and Bioprocess, School of Chemical Engineering, State University of Campinas (UNICAMP), Campinas, SP, Brazil.
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de Souza Pohren R, Rocha JAV, Horn KA, Vargas VMF. Bioremediation of soils contaminated by PAHs: Mutagenicity as a tool to validate environmental quality. CHEMOSPHERE 2019; 214:659-668. [PMID: 30292048 DOI: 10.1016/j.chemosphere.2018.08.020] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Revised: 08/05/2018] [Accepted: 08/06/2018] [Indexed: 06/08/2023]
Abstract
Bioremediation can be used as one of the decontamination techniques for areas contamined by polycyclic aromatic hydrocarbons (PAHs). However the effective biodegradation of these compounds must take into account the possible toxic and mutagenic effects that might persist. In this study the mutagenic potential of soil samples from an area contaminated by wood preservatives was evaluated. The area had already been submitted to a simulated bioremediation process in a microcosm, using two different inoculums (1 and 2), and comparing them to the decay of PAHs. Organic extracts were prepared before and after bioremediation, where the 16 PAHs considered a priority by USEPA were analyzed and tested using the Salmonella/microsome assay. The extracts were analyzed in strains TA98, TA97a and TA100 (+S9mix/-S9mix), YG1041 and YG1042. Considering Inoculum 1 only as bioaugmented and Inoculum 2 also stimulated and enriched, the concentrations of PAHs and mutagenic effect were different. The former identified a greater reduction of mutagenesis and a smaller decrease of PAHs while the latter showed greater mutagenic power even associated with the greatest reduction of PAHS. The possible generation of degradation byproducts with high mutagenic power after a partial biodegradation process can be considered. In strains YG1041 and YG 1042 the mutagenesis values before bioremediation were 747 and 567 rev/g soil, respectively. Although the efficiency of bioremediation was observed, the associated damage indicates that the analysis of contaminants and their relationship with mutagenic effects are a fundamental stage for the effective evaluation of the risks and efficiency of bioremediation processes.
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Affiliation(s)
- Roberta de Souza Pohren
- Programa de Pós-graduação em Ecologia, Universidade Federal do Rio Grande do Sul (UFRGS), Av. Bento Gonçalves, 9500, Cx Postal 15007, CEP 91501-970, Porto Alegre, RS, Brazil; Departamento de Pesquisas e Análises Laboratoriais, Fundação Estadual de Proteção Ambiental Henrique Luís Roessler (FEPAM), Rua Aurélio Porto, 37, 90620-090, Porto Alegre, RS, Brazil; Instituto de Oceanografia, Universidade Federal do Rio Grande (FURG), Av. Itália, km 8, Carreiros, CEP, 96.203-900, Rio Grande, RS, Brazil.
| | - Jocelita Aparecida Vaz Rocha
- Programa de Pós-graduação em Ecologia, Universidade Federal do Rio Grande do Sul (UFRGS), Av. Bento Gonçalves, 9500, Cx Postal 15007, CEP 91501-970, Porto Alegre, RS, Brazil; Departamento de Pesquisas e Análises Laboratoriais, Fundação Estadual de Proteção Ambiental Henrique Luís Roessler (FEPAM), Rua Aurélio Porto, 37, 90620-090, Porto Alegre, RS, Brazil
| | - Kauê Assis Horn
- Programa de Pós-graduação em Ecologia, Universidade Federal do Rio Grande do Sul (UFRGS), Av. Bento Gonçalves, 9500, Cx Postal 15007, CEP 91501-970, Porto Alegre, RS, Brazil; Departamento de Pesquisas e Análises Laboratoriais, Fundação Estadual de Proteção Ambiental Henrique Luís Roessler (FEPAM), Rua Aurélio Porto, 37, 90620-090, Porto Alegre, RS, Brazil
| | - Vera Maria Ferrão Vargas
- Programa de Pós-graduação em Ecologia, Universidade Federal do Rio Grande do Sul (UFRGS), Av. Bento Gonçalves, 9500, Cx Postal 15007, CEP 91501-970, Porto Alegre, RS, Brazil; Departamento de Pesquisas e Análises Laboratoriais, Fundação Estadual de Proteção Ambiental Henrique Luís Roessler (FEPAM), Rua Aurélio Porto, 37, 90620-090, Porto Alegre, RS, Brazil.
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Sommaggio LRD, Mazzeo DEC, Pamplona-Silva MT, Marin-Morales MA. Evaluation of the potential agricultural use of biostimulated sewage sludge using mammalian cell culture assays. CHEMOSPHERE 2018; 199:10-15. [PMID: 29427809 DOI: 10.1016/j.chemosphere.2018.01.144] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Revised: 12/30/2017] [Accepted: 01/27/2018] [Indexed: 06/08/2023]
Abstract
Among the bioremediation processes, biostimulation is an effective methodology for the decontamination of organic waste by the addition of agents that stimulate the indigenous microbiota development. Rice hull is a biostimulating agent that promotes the aeration of edaphic systems and stimulates the aerobiotic activity of soil microorganisms. The present study aimed to evaluate the efficacy of the bioremediation and biostimulation processes in reducing the toxicity of sewage sludge (SS) and to evaluate its possible application in agriculture using cytotoxic and genotoxic assays in human hepatoma cells (HepG2). SS of domestic origin was tested as both the pure product (PSS) and mixed with soil (S) and with a stimulating agent, such as rice hull (RH), in different proportions (SS + S and SS + S + RH); we also examined different remediation periods (3 months - T1 and 6 months - T2). For the PSS sample, a significant induction of micronucleus (MN) in T2 was observed with nuclear buds in all of the periods assessed, and we observed the presence of more than one alteration per cell (MN and nuclear bud) in T1 and T2. The PSS sample caused genotoxic effects in the HepG2 cells even after being bioremediated. For the samples containing soil and/or rice hull, no toxic effects were observed in the test system used. Therefore, the addition of SS to agricultural soils should be conducted with caution, and it is important that the SS undergoes a remediation process, such as bioremediation and biostimulation treatments.
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Affiliation(s)
- Lais Roberta Deroldo Sommaggio
- Department of Biology, Institute of Biosciences, São Paulo State University (Unesp), Av. 24-A, 1515, 13506-900 Rio Claro, SP, Brazil.
| | - Dânia Elisa Christofoletti Mazzeo
- Department of Analytical Chemistry, Institute of Chemistry, São Paulo State University (Unesp), Rua Professor Francisco Degni, 55, 14800-060, Araraquara, SP, Brazil.
| | - Maria Tereza Pamplona-Silva
- Department of Biology, Institute of Biosciences, São Paulo State University (Unesp), Av. 24-A, 1515, 13506-900 Rio Claro, SP, Brazil.
| | - Maria Aparecida Marin-Morales
- Department of Biology, Institute of Biosciences, São Paulo State University (Unesp), Av. 24-A, 1515, 13506-900 Rio Claro, SP, Brazil.
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