Reducing biosolids from a membrane bioreactor system: Assessing the effects on carbon and nutrient removal, membrane fouling and greenhouse gas emissions.

This study presents the effects on carbon and nutrient removal, membrane fouling and greenhouse gas (GHG) emissions of an Oxic-Settling-Anaerobic (OSA) - Membrane Bioreactor (MBR) pilot plant fed with real wastewater. The influence of three sludge return internal ratios (IR) was investigated by testing 45, 75 and 100%. The results showed that with the increase of IR, the biological sludge production substantially decreased by 85.8% due to the combination of cell lysis and endogenous metabolism. However, a worsening of ammonia removal efficiencies occurred (from 94.5 % to 84.7 with an IR value of 45 and 100%, respectively) mostly due to the ammonia release caused by cell lysis under anaerobic conditions. The N2O emission factor increased with the rise of IR (namely, from 2.17% to 2.54% of the total influent nitrogen). In addition, a variation of carbon footprint (CF) (0.78, 0.62 and 0.75 kgCO2eq m-3 with 45, 75 and 100% IR, respectively) occurred with IR mainly due to the different energy consumption and carbon oxidation during the three periods. The study's relevance is to address the optimal operating conditions in view of reducing sludge production. In this light, the need to identify a trade-off between the advantages of reducing sludge production and the disadvantages of increasing membrane fouling and GHG emissions must be identified in the future.

Agronomic and phytotoxicity test with biosolids from anaerobic CO-DIGESTION with temperature and micro-organism phase separation, based on sewage sludge, vinasse and poultry manure.

This study deals with energy and agronomic valorisation by anaerobic co-digestion with temperature and microorganism phase separation of sewage sludge, vinasse and poultry manure, with the aim of achieving an integral waste management, obtaining bioenergy and biofertilizer that returns nutrients to the soil in a natural way. The yields obtained were 40 mL H2/gVS and 391 mLCH4/gVS. The resulting effluent showed more than 98 % removal of E. coli and Total Coliforms, as well as total removal of Salmonella. The results obtained in the phytotoxicity tests showed that all the proportions studied had phytostimulant and phytonutrient properties, with 20 % having the highest germination index (GI) with mean values of 145.30 %. Finally, the agronomic trial carried out with strawberry crops (Fragaria sp.) showed that the addition of this biosolid has fertilising properties and can be used as an agronomic amendment, with an increase of 145 % in fresh weight and 102.5 % in dry weight, and fruit production doubled with respect to the control. The ANOVA statistical study corroborated that there were significant differences in crop growth when applying different proportions of biofertilizer in the fertilizer. Therefore, these results show that this technology is promising and would contribute environmentally, socially and economically to the transfer towards a circular economy model.

Tracing the origins of plastics in biosolids: The role of sewerage pipe materials and trade waste.

Plastics are ubiquitous in virtually every environment on earth. While the specific sources of plastics entering wastewater are not well known, growing evidence suggests sewage sludge (biosolids) can be a sink for plastics. One potential source could be the sewerage pipe materials used to transport sewage between premises and wastewater treatment plants (WWTPs). To evaluate the significance of sewerage piping as a source of biosolids plastics concentrations, we compared the proportion of the total network (by length and surface area) of polyethylene (PE), polyvinylchloride (PVC), and polypropylene (PP) pipes from 10 WWTPs against their biosolids mass concentrations (mg plastic/g biosolid). Among the 10 catchments, the percentage of the network consisting of PP piping ranged from 0 to 1 %, with 0.8-21 % for PE, and 8-73 % for PVC. Biosolids plastics concentrations ranged from 0.09 to 8.62 mg/g (mg plastic/g biosolid) for PP and PE, respectively. For all three plastics, there was no significant Pearson correlation (r < 0.4) between the biosolids concentration (dry weight mg/g) and the proportion of the network material of the sewerage piping as plastic (either length or surface area). A comparison of trade waste entering a subset of 6 WWTP showed the highest biosolid principal components analysis (PCA) associations between loads of plastics (g/day) and automotive wash bays, general manufacturing, hospitals, laboratories, food manufacturing, laundry and dry cleaning, and cooling towers. A stepwise regression analysis indicated pipe length and surface area, as well as automotive wash bays and food manufacturing may be significant. While our data gave mixed results on the attribution of the sources of plastics entering WWTPs, it suggests that sewerage infrastructure and trade waste may play some role. Future studies should investigate the leachability of sewerage infrastructure and contributions from specific trade waste categories to determine their significance in plastics entering WWTPs.

Comparison of ATR-FTIR and NIR spectroscopy for identification of microplastics in biosolids.

Biosolids are considered a potentially major input of microplastics (MPs) to agricultural soils. Our study aims to identify the polymeric origin of MPs extracted from biosolid samples by comparing their Attenuated Total Reflection (ATR) - Fourier-transform infrared (FTIR) spectra with the corresponding near-infrared (NIR) spectra. The reflectance spectra were preprocessed by Savitzky-Golay (SG), first derivative (FD) and compared with analogous spectra acquired on a set of fifty-two selected commercial plastic (SCP) materials collected from readily available products. According to the results portrayed in radar chart and built from both ATR-FTIR and NIR spectral datasets, the MPs showed high correlations with polymers such as polyethylene (LDPE, HDPE), polyethylene terephthalate (PET), polystyrene (PS), polypropylene (PP) and polyamide (PA), determined in SCP samples. Each unknown MP sample had on average three or more links to several types of SCP, according to the correlation coefficients for each polymer ranging from 0.7 up to 1. The comparison analysis classified the majority of MPs as composed mainly by LDPE/HDPE, according to the top correlation coefficients (r > 0.90). PP and PET were better identified with NIR than ATR-FTIR. In contrast to ATR-FTIR analysis, NIR was unable to identify PS. Based on these results, the primary sources of MPs in the biosolids could be identified as discarded consumer packaging (containers, bags, bottles) and fibers from laundry, disposable glove, and cleaning cloth. SYNOPSIS: Microplastics (MPs) are considered contaminants of emerging concern. This study compares two simple and fast spectroscopy techniques to identify microplastics in the biosolid matrix.

Characterizing the Microplastic Content of Biosolids in Southern Ontario, Canada.

The application of biosolids to agricultural land has been identified as a major pathway of microplastic (MP) pollution to the environment. Very little research, however, has been done on the MP content of biosolids within Canada. Fifteen biosolid samples from different treatment processes (liquid, dewatered, pelletized, and alkali-stabilized) were collected from 11 sources across southern Ontario to quantify and characterize the MP load within them. All samples exhibited MP concentrations ranging from 188 200 (±24 161) to 512 000 (±28 571) MPs/kg dry weight and from 4122 (±231) to 453 746 (±38 194) MPs/kg wet weight. Field amendment of these biosolids can introduce up to 3.73 × 106 to 4.12 × 108 MP/ha of agricultural soil. There was no significant difference in the MP concentrations of liquid, dewatered, and pelletized samples; but a reduction in MP content was observed in alkali-stabilized biosolids. Fragments composed 57.6% of the MPs identified, while 36.7% were fibers. In addition, MPs showed an exponential increase in abundance with decreasing size. Characterization of MPs confirmed that polyester was the most abundant, while polyethylene, polypropylene, polyamide, polyacrylamide, and polyurethane were present across the majority of biosolid samples. The results of the present study provide an estimate of the potential extent of MP contamination to agricultural fields through the amendment of biosolids. Environ Toxicol Chem 2024;43:793-806. © 2023 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Pulp mill biosolids mitigate soil greenhouse gas emissions from applied urea and improve soil fertility in a hybrid poplar plantation.

Pulp mill biosolids (hereafter 'biosolids') could be used as an organic amendment to improve soil fertility and promote crop growth; however, it is unclear how the application of biosolids affects soil greenhouse gas emissions and the mechanisms underlying these effects. Here, we conducted a 2-year field experiment on a 6-year-old hybrid poplar plantation in northern Alberta, Canada, to compare the effects of biosolids, conventional mineral fertilizer (urea), and urea + biosolids on soil CO2, CH4 N2O emissions, as well as soil chemical and microbial properties. We found that the addition of biosolids increased soil CO2 and N2O emissions by 21 and 17%, respectively, while urea addition increased their emissions by 30 and 83%, respectively. However, the addition of urea did not affect soil CO2 emissions when biosolids were also applied. The addition of biosolids and biosolids + urea increased soil dissolved organic carbon (DOC) and microbial biomass C (MBC), while urea addition and biosolids + urea addition increased soil inorganic N, available P and denitrifying enzyme activity (DEA). Furthermore, the CO2 and N2O emissions were positively, while the CH4 emissions were negatively associated with soil DOC, inorganic N, available phosphorus, MBC, microbial biomass N, and DEA. In addition, soil CO2, CH4 and N2O emissions were also strongly associated with soil microbial community composition. We conclude that the application of the combination of biosolids and chemical N fertilizer (urea) could be a beneficial approach for both the disposal and use of pulp mill wastes, by reducing greenhouse gas emissions and improving soil fertility.

The effect of polystyrene microplastic and biosolid application on the toxicity and bioaccumulation of cadmium for Enchytraeus crypticus.

Plastics smaller than 5 mm that end up in a soil environment are known as microplastics (MPs). Microplastics have become a common contaminant in agricultural areas in addition to metals. However, the effect of cadmium (Cd) on soil organisms has not been clearly defined in the presence of MPs. In addition to MPs, biosolid application as a soil amendment in agricultural lands is also leading to shifts in soil conditions, such as the concentrations of nutrients and organic matter. Therefore, the aim of this study is to investigate the toxicity and bioaccumulation of Cd for Enchytraeus crypticus in the presence of polystyrene (PS)-MPs and biosolids to provide insight into their possible interactions. The lethal toxic concentration (LC50) for Cd was higher than 650 mg Cd/kg dry soil for all conditions. The presence of PS-MPs increased the toxicity of Cd for which EC50 was 102 and 38 mg Cd/kg dry soil without and with Cd, respectively, which may be the result of an increased exposure rate through adsorption of Cd on PS-MPs. On the contrary, the presence of biosolids decreased the toxicity of Cd where EC50 was 193 and 473 mg Cd/kg dry soil for the sets applied with 0.6 and 0.9 g biosolids, respectively. Coexistence of biosolids and PS-MPs decreased the reproduction toxicity of Cd, which is similar to the biosolid effect (EC50 is 305 mg Cd/kg dry soil). Bioaccumulation of Cd only positively correlated with its initial concentration in soil and was not affected by the presence of PS-MPs or biosolids. Integr Environ Assess Manag 2023;19:489-500. © 2022 SETAC.

The Effect of Municipal Biosolids on the Growth, Physiology and Synthesis of Phenolic Compounds in Ocimum basilicum L.

The continuous development of drinking water networks is leading to the production of increasing amounts of waste water and sewage sludge. Secondary-treated sewage sludge is called biosolids and can be used as fertilizers in agriculture due to its rich nutrient content. The aim of this study was to evaluate the effects of biosolids mixed with an eroded soil on the morphology, physiology and synthesis of bioactive compounds in basil. The study was performed in pots under laboratory-controlled conditions. In total, four substrates were tested: S1 biosolids 100%, S2 biosolids 15% + eroded soil 85%, S3 eroded soil 100% and S4 control (commercial growing substrate). At the morphological level, a significant increase in plant height, number of branches, fresh biomass and dry biomass was found in the S2 variant. At the physiological level, photosynthesis and chlorophyll content did not vary significantly, but the quantum yield of PSII (ΦPSII) was significantly higher at S1 and S2. The oxidative status evaluated by determining the activity of SOD, POD and CAT enzymes was better in S2 and S3 compared to S3. Regarding the synthesis of bioactive compounds (rosmarinic acid, caffeic acid and gallic acid), it was stimulated in S1 and S2. In conclusion, biosolids application stimulated the stress response mechanisms in basil plants by increasing the quantum yield chlorophyll fluorescence and catalase activity, alleviating the negative effects of eroded soil.

Identification and Quantification of Micro-Bioplastics in Environmental Samples by Pyrolysis-Gas Chromatography-Mass Spectrometry.

Bioplastics are materials that are biobased and/or biodegradable, but not necessarily both. Concerns about environmental plastic pollution are constantly growing with increasing demand for substituting fossil-based plastics with those made using renewable resource feedstocks. For many conventional bioplastics to completely decompose/degrade, they require specific environmental conditions that are rarely met in natural ecosystems, leading to rapid formation of micro-bioplastics. As global bioplastic production and consumption/use continue to increase, there is growing concern regarding the potential for environmental pollution from micro-bioplastics. However, the actual extent of their environmental occurrence and potential impacts remains unclear, and there is insufficient mass concentration-based quantitative data due to the lack of quantitative analytical methods. This study developed and validated an analytical method coupling pressurized liquid extraction and pyrolysis-gas chromatography-mass spectrometry combined with thermochemolysis to simultaneously identify and quantify five targeted micro-bioplastics (i.e., polylactic acid (PLA), polyhydroxyalkanoate, polybutylene succinate, polycaprolactone, and polybutylene adipate terephthalate (PBAT)) in environmental samples on a polymer-specific mass-based concentration. The recovery of spiked micro-bioplastics in environmental samples (biosolids) ranged from 74 to 116%. The limits of quantification for the target micro-bioplastics were between 0.02 and 0.05 mg/g. PLA and PBAT were commonly detected in wastewater, biosolids, and sediment samples at concentrations between 0.07 and 0.18 mg/g. The presented analytical method enables the accurate identification, quantification, and monitoring of micro-bioplastics in environmental samples. This study quantified five micro-bioplastic types in complex environmental samples for the first time, filling in gaps in our knowledge about bioplastic pollution and providing a useful methodology and important reference data for future research.

Greenhouse gas emissions following biosolids application to farmland: Estimates from the DeNitrification and DeComposition model.

Municipal wastewater sludge may be processed into biosolids and applied to farmland for crop production, rather than be disposed of in landfills. Biosolids supply plant nutrients and increase soil organic carbon but also contribute to the production of greenhouse gases (GHGs). Computational models must therefore be refined to estimate the contribution of these gases to national GHG inventories. The DeNitrification and DeComposition (DNDC) model was evaluated for processes regulating crop growth, GHGs and soil C&N dynamics to determine its suitability for informing policy decision-making and advancing Canada's GHG inventory. Three years (2017-2019) of data were collected from replicated corn (Zea mays L.) plots in Quebec, Canada. The plots received 120 kg of available N ha-1 y-1 in mesophilic anaerobically digested biosolids, composted biosolids, alkaline-stabilized biosolids, urea, or combinations of these, while control plots were left unfertilized. Treatments receiving digested biosolids emitted more nitrous oxide (N2O) during the growing season than other treatments, while carbon dioxide (CO2) emissions were similar between treatments. After calibration, DNDC estimates were within the 95% confidence interval of the measured variables. Correlation coefficients (r) indicated discrepancies in trends between the estimated and measured values for daily CO2 and N2O emissions. These emissions were underestimated in the early and mid-growing season of 2018. They were more variable from plots fertilized with composted or alkaline-stabilized biosolids than from those with digested biosolids. Annual N2O emissions (r = 0.8), crop yields (r = 0.5), and soil organic carbon (r = 0.4) were modelled with higher accuracy than cumulative CO2 emissions (r = 0.3) and total soil N (r = 0.1). These findings suggest that DNDC is suitable for estimating field-scale N2O emissions following biosolids application, but estimates of CO2 emissions could be improved, perhaps by disaggregating the biosolids from the soil organic matter pools in the decomposition subroutines.

Occurrence of viruses in sewage sludge: A systematic review.

Enteric viruses are of great importance in wastewater due to their high excretion from infected individuals, low removal in wastewater treatment processes, long-time survival in the environment, and low infectious dose. Among the other viruses, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) surveillance in wastewater systems has received particular attention as a result of the current COVID-19 epidemic. Viruses adhering to solid particles in wastewater treatment processes will end up as sewage sludge, and therefore insufficient sludge treatment may result in viral particles dissemination into the environment. Here, we review data on viruses' presence in sewage sludge, their detection and concentration methods, and information on human health issues associated with sewage sludge land application. We used combinations of the following keywords in the Scopus, Web of Science (WOS), and PubMed databases, which were published between 2010 and January 21th, 2022: sludge (sewage sludge, biosolids, sewage solids, wastewater solids) and virus (enteric virus, viral particles, viral contamination, SARS-CoV-2, coronavirus). The sources were searched twice, once with and then without the common enteric virus names (adenovirus, rotavirus, norovirus, enterovirus, hepatitis A virus). Studies suggest adenovirus and norovirus as the most prevalent enteric viruses in sewage sludge. Indeed, other viruses include rotavirus, hepatitis A virus, and enterovirus were frequently found in sewage sludge samples. Untreated biological sludge and thickened sludge showed more viral contamination level than digested sludge and the lowest prevalence of viruses was reported in lime stabilized sludge. The review reveals that land application of sewage sludge may pose viral infection risks to people due to accidently ingestion of sludge or intake of crops grown in biosolids amended soil. Moreover, contamination of groundwater and/or surface water may occur due to land application of sewage sludge.

Greenhouse gas emissions of biosolid and cow manure during composting and vermicomposting and when applied to soil cultivated with wheat (Triticum sp. L.).

Biosolids are a by-product of wastewater treatment, and their nutritional composition makes them ideal for fertilizing crops. However, pre-treatments, such as conditioning and/or (vermi)composting, are often required to stabilize the product and remove pathogens. Biosolids, cow manure, and a 50-50% mixture were conditioned for 21 days, composted or vermicomposted with Eisenia fetida (Savigny 1826) for 28 days, and applied to soil cultivated with wheat (Triticum sp. L.), while emissions of nitrous oxide (N2O), methane (CH4), and carbon dioxide (CO2) were monitored. Emissions of CH4 were large from the biosolid and N2O from the cow manure during conditioning. Emissions of CH4 remained high during (vermi)composting of the biosolids, while the emissions of N2O from the cow manure dropped. The addition of E. fetida did not affect the emissions of greenhouse gases during (vermi)composting. The emission of N2O was higher when (vermi)composted biosolid was applied to soil cultivated with wheat than when (vermi)composted cow manure was applied. The global warming potential (GWP) of the sum of the emitted greenhouse gases (GHG) during conditioning, (vermi)composting, and when the final product was applied to soil was 3 times larger from the cow manure than from the biosolid, but mixing biosolid with cow manure eliminated that difference. It was concluded that mixing biosolid with cow manure might be a simple way to reduce the GWP of the emitted GHG during storage, (vermi)composting, and when applied to soil.

Does size matter? Quantification of plastics associated with size fractionated biosolids.

This study investigated the occurrence and contribution of plastic particles associated with size fractionated biosolids to the total concentration in biosolids (treated sewage sludge) samples collected from 20 wastewater treatment plants (WWTP) across Australia. This was achieved through sequential size fractionation of biosolids samples to quantify the mass concentration of 7 common plastics across a range of biosolids size fractions, including below 25 µm which has not been assessed in many previous studies. Quantitative analysis was performed by pressurized liquid extraction followed by pyrolysis coupled to gas chromatography - mass spectrometry. Of the total quantified plastics (Σ7plastics), the greatest proportion (27%) of the total mass were identified in the nominal <25 µm sized biosolids fraction. Polyethylene dominated the polymer mass in every size fraction, even though profiles varied between WWTPs. When comparing the sum of all sites for each sized biosolids fraction, the plurality of the polyethylene, polyvinyl-chloride, polystyrene, polypropylene, polycarbonate, and polyethylene-terephthalate concentrations were associated with the smallest size fraction (<25 µm). We confirm for the first time the presence of plastic particles in biosolids below a size fraction that is not captured by many methods. This is important, because of the potential greater significance of plastics in the low sizes to environmental and human health.

Avaliação da presença de fármacos em biossólido compostado proveniente de Estação de Tratamento de Esgotos / Evaluation of the presence of drugs in composted biosolid from sewage treatment plant

O comportamento e o destino dos fármacos e seus metabólitos no meio aquático, assim como seus efeitos na biota e saúde humana, têm sido objeto de estudos em âmbito global. No entanto, poucas pesquisas relacionam parâmetros operacionais e físico-químicos à remoção dos fármacos em Estações de Tratamento de Esgotos (ETE). Os principais processos responsáveis pela redução da concentração destes contaminantes na fase aquosa, durante o tratamento de esgotos, são a biodegradação e a sorção à fase sólida. No que diz respeito à qualidade dos lodos produzidos, um aspecto ainda pouco estudado refere-se à identificação de poluentes emergentes, substâncias presentes no ambiente e que usualmente não são monitoradas, especialmente pela ausência de regulamentação legal nos países, podendo apresentar risco potencial à saúde humana e ao meio ambiente. Desse modo, o presente estudo tem por objetivo identificar, quantificar e avaliar a eficiência de remoção de fármacos presentes em biossólidos provenientes de uma ETE, antes e após o processo de compostagem, utilizando técnicas de cromatografia UFLCTM e espectrometria MS-MS, e avaliar os fármacos escolhidos para estudo, com base no modelo QSAR (ECOSAR-EPA), visando identificar o potencial de bioacumulação e ecotoxicidade dessas substâncias no ambiente, de acordo com as propriedades físico-químicas. De acordo com os resultados obtidos observa-se que houve redução na concentração dos compostos avaliados, indicando tendência à biodegradação ou redução na biodisposição dos mesmos. O processo de compostagem estudado, além de mostrar-se adequado para a produção de um biossólido com características compatíveis com as requeridas para o uso agrícola, possibilitou constatar a eficiência do processo como alternativa para o tratamento desses contaminantes presentes no lodo de esgotos. Possíveis interações que possam ocorrer com outros fármacos presentes no ambiente, em relação a concentrações residuais e metabólitos gerados, os quais não foram investigados no presente estudo, apontam para a necessidade de estudos em relação aos mecanismos farmacocinéticos e farmacodinâmicos para entendimento dos mecanismos de reação envolvidos na formação e toxicidade de seus metabólitos. A presença destes compostos nas várias matrizes ambientais denota a importância das pesquisas nessa área, e a adoção de boas práticas operacionais visando garantir a qualidade e a segurança requeridas na utilização benéfica do lodo de esgotos, principalmente para fins agrícolas.

The behavior and fate of drugs and their metabolites in the aquatic environment, as well as their effects on biota and human health, have been the object of studies on a global scale. However, few research relate operational and physicochemical parameters to the removal of drugs in Sewage Treatment Plants (ETE). The main processes responsible for reducing the concentration of these contaminants in the aqueous phase, during sewage treatment, are biodegradation and sorption to the solid phase. Regarding the quality of the sludge produced, an aspect that has still been poorly studied refers to the identification of emerging pollutants, substances present in the environment that are usually not monitored, especially due to the lack of legal regulations in the countries, which may present a potential risk to health. human and the environment. Thus, this study aims to identify, quantify, and evaluate the efficiency of removal of drugs present in biosolids from an ETE, before and after the composting process, using UFLCTM chromatography and MS-MS spectrometry techniques, and evaluate the drugs chosen for study, based on the QSAR model (ECOSAR-EPA), to identify the bioaccumulation potential and ecotoxicity of these substances in the environment, according to their physicochemical properties. According to the results obtained, it is observed that there was a reduction in the concentration of the compounds evaluated, indicating a tendency to biodegradation or a reduction in their biodisposition. The composting process studied, in addition to being suitable to produce biosolids with characteristics compatible with those required for agricultural use, made it possible to verify the efficiency of the process as an alternative for the treatment of these contaminants present in sewage sludge. Possible interactions that may occur with other drugs present in the environment, in relation to residual concentrations and generated metabolites, which were not investigated in this study, point to the need for studies in relation to pharmacokinetic and pharmacodynamic mechanisms to understand the reaction mechanisms involved in the formation and toxicity of its metabolites. The presence of these compounds in the various environmental matrices denotes the importance of research in this area, and the adoption of good operational practices to ensure the quality and safety required in the beneficial use of sewage sludge, mainly for agricultural purposes.

Morphological and transcriptomic alterations in neonatal lamb testes following developmental exposure to low-level environmental chemical mixture.

Exposure to anthropogenic environmental chemical mixtures could be contributing to the decline in male reproductive health. This study used the biosolid treated pasture (BTP) sheep model to assess the effects of exposure to low-dose chemical mixtures. Maternal BTP exposure was associated with lower plasma testosterone concentrations, a greater proportion of Sertoli cell-only seminiferous tubules, and fewer gonocytes in the testes of neonatal offspring. Transcriptome analysis highlighted changes in testicular mTOR signalling, including lower expression of two mTOR complex components. Transcriptomic hierarchical analysis relative to the phenotypic severity demonstrated distinct differential responses to maternal BTP exposure during pregnancy. Transcriptome analysis between phenotypically normal and abnormal BTP lambs demonstrated separate responses within the cAMP and PI3K signalling pathways towards CREB. Together, the results provide a potential mechanistic explanation for adverse effects. Exposure could lower gonocyte numbers through mTOR mediated autophagy, but CREB mediated survival factors may act to increase germ cell survival.

High-rate blackwater anaerobic digestion under septic tank conditions with the amendment of biosolids-derived biochar synthesized at different temperatures.

Septic tanks have been widely used for blackwater treatment in developing countries, while high-rate septic tanks with improved methane recovery are yet to be achieved. This study investigated biosolids-derived biochar (synthesized at 300℃, 425℃, and 550℃) as an additive for developing high-rate septic tanks. The experiments were conducted with anaerobic bioreactors operated with synthetic blackwater under septic tank conditions. All biochar amended reactors demonstrated a steady increase in daily methane production for increasing OLR from 0.08 to 3 g COD/L/d. The control reactor showed significant process disturbances at OLRs ≥ 2 g COD/L/d with an accumulation of volatile fatty acids followed by pH drop. At OLR of 3 g COD/L/d, the daily methane production from biochar amended reactors was ~ 4.3 times higher than the control (300 vs. 70 mL per day). Biochar addition established a robust microbiome consisted of a higher abundance of hydrogenotrophic and acetoclastic methanogens and hydrogen-producing fermentative bacteria.

Greener gas? Impact of biosolids on carbon intensity of switchgrass ethanol.

Synthetic fertilizers make up a significant fraction of the energy required to grow switchgrass (Panicum virgatum L.) for ethanol production. A field study compared biosolids and synthetic fertilizers on biomass yield, ethanol production, and nitrous oxide (N2 O) emissions of switchgrass to determine if using an alternative source of nutrient would lower the energy density of the fuel. Minimal N2 O emissions were observed the first year of the study (0.99 ± 1.5 g N2 O ha-1 d-1 for biosolids), with no difference between treatments. Biosolids were added in excess of agronomic rates, and gas samples were collected immediately after irrigation for the subsequent years to examine maximum N2 O emissions. Mean Year 2 emissions increased for fertilizers to 1.8 ± 8 g N2 O ha-1 d-1 (n = 131) and to 3.73 ± 10.2 g N2 O ha-1 d-1 (n = 130) for biosolids-amended soils. Emissions in Year 3 were similar to Year 2. Yield was similar and ranged from 3.7 ± 5 to 11 ± 1.1 and from 5.0 ± 0.2 to 13.4 ± 1.7 Mg ha-1 for biosolids and fertilizer, respectively. The potential ethanol yield was 365 ± 28 L Mg-1 and 374 ± 34 L Mg-1 for the biosolids- and fertilizer-grown grass, respectively. Greenhouse gas emissions associated with fertilizer production were considered for N, P, and K and totaled 1,653 kg carbon dioxide equivalent (CO2 e) ha-1 . The equivalent credits for substitution of biosolids (18 Mg ha-1 ) were -2,492 kg CO2 e ha-1 . Nitrous oxide emissions were calculated based on 1% of total N applied for agronomic applications and were 8,600 and 3,500 g N2 O ha-1 for the biosolids and fertilizer treatments, respectively. Total carbon costs associated with fertilization were 2,700 kg CO2 e ha-1 for fertilizer and 60 kg CO2 e ha-1 for biosolids. Using measured N2 O data would have resulted in lower emissions for both treatments.

Yield and biometry of fertilized sugar cane with organomineral fertilizer of sewage sludge and biostimulant / Rendimento e biometria da cana-de-açúcar fertilizada com fertilizante organomineral de lodo de esgoto e bioestimulante

The dependence of mineral fertilizers, increasingly, has brought concern facing the increased demand and because it is a non-renewable mineral resource. The organic fertilization, exclusively, it is impractical in large scale, however, the combination of organic and mineral sources have already proved to be feasible, both from the point of view of nutrition of plants as well as in the aspect of recycling of urban and industrial waste by agriculture. This research had as objective to determine the efficiency of aorganomineral fertilizer formulated on the basis of sewage sludge in substitution of mineral fertilizer in the cultivation of sugar cane in environments with different levels of soil fertility. An experiment was conducted in greater soil fertility, in the Institute Federal Goiano­Campus, Morrinhos-GO, Brazil. The other, less soil fertility, was implanted in the ethanol industry Tijuco Valley, located in Rio do Peixe, district of Prata-MG, Brazil. The experimental design was randomized blocks in a factorial 5 x 2 +1 being five doses, with and without a biostimulant plus an additional with mineral fertilization, in four replications. The doses werein function of fertilization recommendation of planting and coverage for each environment, consisting of: 100 % of the mineral source and percentage 0; 60; 80; 100 and 120 % of organomineral fertilizer. We evaluated the productivity, tillering, diameter and height of stem in Prata-MG the different percentages of the fertilization of planting favored and increased productivity, height and stem diameter of sugar cane; the use of biostimulants not contributed to increase crop yield. In Morrinhos-GO, the different percentage of planting fertilization did not increase the productivity, tillering, height and diameter of the sugarcane stem; the use of biostimulants increases the productivity yield of sugarcane. Organomineral fertilizer based on biosolids is similar to fertilization with mineral fertilizer in environments

A dependência de fertilizantes minerais, cada vez mais, trouxe preocupação frente ao aumento da demanda e por ser um recurso mineral não renovável. A adubação orgânica, em exclusivo, é impraticável em larga escala, no entanto, a combinação de fontes orgânicas e minerais já se mostrouviável, tanto do ponto de vista nutricional das plantas como no aspecto de reciclagem de áreas urbanas e urbanas como de resíduos industriais pela agricultura. Esta pesquisa teve como objetivo determinar a eficiência de um fertilizante organomineral formulado à base de lodo de esgoto em substituição ao adubo mineral no cultivo de cana-de-açúcar em ambientes com diferentes níveis de fertilidade do solo. Um experimento foi conduzido em ambiente de maior fertilidade do solo, no Instituto Federal Goiano -Campus, Morrinhos-GO, Brasil. O outro, em local com menor fertilidade do solo, na indústria de etanol no Vale do Tijuco, localizado no município de Rio do Peixe, no município de Prata-MG, Brasil. Utilizou-se o delineamento experimental de blocos ao acaso, em esquema fatorial 5 x 2 +1, correspondente a cinco níveis de adubação, com e sem bioestimulante mais um tratamento adicional com adubação mineral, em quatro repetições. As doses foram em função da recomendação de adubação de plantio e cobertura para cada ambiente, sendo composta por: 100% da fonte mineral e porcentagens de 0; 60; 80; 100 e 120% de fertilizante organomineral. Avaliou-se a produtividade, perfilhamento, diâmetro e altura de colmos.Em Prata -MG os diferentes percentuais da adubação de plantio favorece e incrementa produtividade, altura e diâmetro do colmo da cana-de-açúcar; o uso de bioestimulantes não contribui para o rendimento desta cultura. Em Morrinhos -GO os diferentes percentuais da adubação de plantio não melhora produtividade, perfilhamento, altura e diâmetro do colmo da cana-de-açúcar; o uso de bioestimulantes incrementa rendimento de produtividade da cana-de-açúcar. A adubação com fertilizante organomineral a base de biossólido é semelhante a adubação com fertilizante mineral nos ambientes

The significance of cadmium entering the human food chain via livestock ingestion from the agricultural use of biosolids, with special reference to the UK.

When biosolids are applied to agricultural soil, potentially toxic elements (PTEs) accumulate in the topsoil, although it takes many repeated applications to reach soil limit values. Two programmes of UK government-funded research were commissioned in the 1990s to investigate the transfer of PTEs to the food chain via ingestion by sheep grazing biosolids-amended soil. Here, we critically re-examine this evidence in the light of other published work and current food quality standards. This was particularly motivated by the need to determine the safety of biosolids controls on PTEs in relation to revised and stricter European food quality controls for PTEs in foodstuffs. The major pathway for transfer of PTEs to grazing livestock is via direct ingestion of biosolids or biosolids-amended soil from the soil surface. The main elements of concern for the human diet are cadmium (Cd) and lead (Pb), with Cd being the focus of the current paper. Animal ingestion of plant tissue is also a potential pathway for Cd exposure, which, unlike Pb, can transfer to crop tissues. The concentrations of Cd in the muscle tissue of sheep grazing biosolids-amended soil were generally small and similar to control values. Cadmium concentrations in sheep offal were below the maximum permitted concentration for human consumption. This was despite ingestion of soils exceeding the maximum permissible concentration for Cd in soil (3 mg kg-1 dry soil) by up to three times, at an ingestion rate of 10% total dietary dry matter intake. Grazing trials under practical conditions on high Cd soils demonstrated that the Cd concentrations in sheep offal remained below the food limit value for this element in offal from the combined intakes from biosolids-amended soil and herbage. Futhermore, given the substantial fall in environmental emissions and concentrations in biosolids of this element and, consequently, it cannot accumulate in soil to the limit value, biosolids Cd does not represent an issue for the safety of animal meat products.

Identification and quantification of selected plastics in biosolids by pressurized liquid extraction combined with double-shot pyrolysis gas chromatography-mass spectrometry.

The identification and quantification of selected plastics (polystyrene (PS), polycarbonate (PC), poly-(methyl methacrylate) (PMMA), polypropylene (PP), polyethylene terephthalate (PET), polyethylene (PE) and polyvinyl chloride (PVC)) in biosolids (treated sewage sludge) was performed by pressurized liquid extraction (PLE) combined with double-shot pyrolysis gas chromatography-mass spectrometry. Validation of the method yielded recoveries of between 85 and 128% (mean RSD 11%) at a linear range of between 0.01 and 2 µg. The distribution of plastics within 25 biosolid samples from a single wastewater treatment plant in Australia was assessed. The mass concentration of PE, PVC, PP, PS and PMMA was between 0.1 and 4.1 mg/g dry weight (dw) across all samples, with a total plastic concentration Æ©Plastics of between 2.8 and 6.6 mg/g dw (median = 4.1 mg/g dw). PE was the predominant plastic detected (mean concentration of 2.2 mg/g dw), contributing to 50% of the total of all plastics. Overall, this study demonstrates that pressurized liquid extraction (PLE) combined with double-shot pyrolysis gas chromatography-mass spectrometry can be used to identify and quantify PE, PP, PVC, PS, and PMMA in biosolids.