Conditioning treatments mitigate the levels of fecal pollution indicators in soil during land-application of sewage sludge

Sewage sludge is a major source of fecal pathogens in the environment,and its application to land can result in a significant release of these pathogens into the soil.While conditioning treatments are crucial for improving the dewatering process of sludge,their impact on the presence and behavior of fecal pathogens in soil remains unclear.This study aims to assess four extraction methods for recovering fecal pollution indicators from soil amended with unconditioned and conditioned sludge.The indicators include Escherichia coli(EC),human-specific HF183 Bacteroides(HF183),human adenovirus(HAdV),human BK polyomavirus(BKPyV),human JC polyomavirus(JCPyV),and cross-assembly phage(crAssphage).This study also examines how soil moisture content affects the decay of these fecal pollution indicators in soil amended with raw sludge and investigates the influence of conditioning treatments with cationic polyacrylamide(PAM),Fenton’s reagents,Fe[III]/CaO on their persistence in soil.The results indicated that the direct extraction method was the most effective and unbiased for recovering fecal pollution indicators from sludge-amended soil compared with the three elution-concentration methods.All fecal pollution indicators,except HAdV,remained stable under dry soil conditions,while high soil moisture content(48.39%‒53.14%)slowed the decay rates of these indicators.During the application of sludge to soil,effective control of fecal pollution indicators was observed,with JCPyV and HAdV becoming undetectable within a short period.The log reduction values of HF183,BKPyV,and crAssphage ranged from 0.1 to 2.8 logs after 30 d of cultivation.The application of conditioned sludge,especially Fenton’s reagent-conditioned sludge,resulted in a reduction in human fecal contamination in the receiving soil.Therefore,implementing appropriate conditioning methods,such as using Fenton’s reagent,can effectively mitigate the health risks associated with fecal pathogens.

Three-Year Consecutive Field Application of Erythromycin Fermentation Residue Following Hydrothermal Treatment:Cumulative Effect on Soil Antibiotic Resistance Genes

Fermentation-based antibiotic production results in abundant nutrient-rich fermentation residue with high potential for recycling,but the high antibiotic residual concentration restricts its usefulness(e.g.,in land application as organic fertilizer).In this study,an industrial-scale hydrothermal facility for the treatment of erythromycin fermentation residue(EFR)was investigated,and the potential risk of the long-term soil application of treated EFR promoting environmental antibiotic resistance development was evaluated.The treatment effectively removed bacteria and their DNA,and an erythromycin removal ratio of up to approximately 98%was achieved.The treated EFR was utilized as organic fertilizer for consecutive field applications from 2018 to 2020,with dosages ranging from 3750 to 15000 kg·hm^(-2),resulting in subinhibitory levels of erythromycin(ranging from 0.83-76.00μg·kg^(-1))in soils.Metagenomic shotgun sequencing was then used to characterize the antibiotic resistance genes(ARGs),mobile genetic elements(MGEs),and bacterial community composition of the soils.The soil ARG abundance and diversity did not respond to the treated EFR application in the first year,but gradually changed in the second and third year of application.The highest fold change in relative abundance of macrolide-lincosamide-streptogramin(MLS)and total ARGs were 12.59 and 2.75 times,compared with the control(CK;without application),respectively.The soil MGEs and taxonomic composition showed similar temporal trends to those of the ARGs,and appeared to assist in driving increasing ARG proliferation,as revealed by correlation analysis and structural equation models(SEMs).The relative abundance of particular erm resistance genes(RNA methyltransferase genes)increased significantly in the third year of treated EFR application.The close association of erm with MGEs suggested that horizontal gene transfer played a critical role in the observed erm gene enrichment.Metagenomic binning results demonstrated that the proliferation of mac genecarrying hosts was responsible for the increased abundance of mac genes(efflux pump genes).This study shows that sub-inhibitory levels of erythromycin in soils had a cumulative effect on soil ARGs over time and emphasizes the importance of long-term monitoring for assessing the risk of soil amendment with treated industrial waste.

Characteristics of sewage sludge and distribution of heavy metal in plants with amendment of sewage sludge

In order to better understand land application of sewage sludge, the characterization of heavy metals and organic pollutants were investigated in three different sewage sludges in Shanghai City, China. It was found that the total concentrations of Cd in all of sewage sludge and total concentrations of Zn in Jinshan sewage sludge, as well as those ofZn, Cu, and Ni in Taopu sludge are higher than Chinese regulation limit of pollutants for sludge to be used in agriculture. Leachability of rig in all of studied samples and that of Cd in Taopu sewage sludge exceed the limit values of waste solid extraction standard in China legislation. Based on the characteristics for three kinds of sewage sludge, a pot experiment was conducted to investigate the effect of soil amended with Quyang sewage sludge on the accumulation of heavy metalo.by Begonia semperfloreas-hybr; Ophiopogon japonicas （L.F.） Ker-Gaw; Loropetalum chindense-var, rubrum; Dendranthema morifolium; Viola tricolor; A ntirrhinum majas; Buxas radicans Sieb; Viburnum macrocephalum; Osmanthas fragrans Lour; Cinnamomum camphora siebold and Ligustrum lucidum ait. Results showed that 8 species of plant survived in the amended soil, and moreover they flourished as well as those cultivated in the control soil. The heavy metal concentration in plants varied with species, As, Pb, Cd and Cr concentration being the highest in the four herbaceous species studied, particularly in the roots of D. morifolium. These plants, however, did not show accumulator of As, Pb, Cd and Cr. The highest concentration of Ni and Hg was found in the roots ofD. morifolium, followed by the leaves ofB. semperflorens-hybr. Levels of Zn and Cu were much higher in D. morifolium than in the other plant species. D. morifolium accumulated Ni, Hg, Cu and Zn, which may contribute to the decrease of heavy metal contents in the amended soil. Treatment with sewage sludge did not significantly affect the uptake of heavy metals by the L. chindense-var, rubrum, however, it significantly affected the uptake of heavy metals by D. morifolium.

Utilizing Water Treatment Residuals to Reduce Phosphorus Runoff from Biosolids

Approximately 40% of biosolids （sewage sludge） produced in the U.S. are incinerated or landfilled rather than land applied due to concern over non-point source P （phosphorus） runoff. The objective of this study was to determine the impact of chemical amendments on WEP （water-extractable phosphorus） in applied treatments and DRP （dissolved reactive phosphorus） in runoff from biosolids-amended soils. Rainfall simulations were conducted in 2006 on field plots fertilized with biosolids that had been treated with alum [（A12804）3＂ 14H20], ferric chloride （FeC13） or an alum-based WTR （water treatment residual） at a rate of 20% （wt/wt） to reduce DRP in runoff. In 2007, rainfall simulations were conducted using WTR/biosolid blends of 15% and 30% （wt/wt） that were allowed to incubate for three weeks prior to application. Cumulative DRP runoff load observed for the 20% WTR treatment was not significantly different from other chemical treatments and resulted in a 45% reduction in DRP runoff as compared to the untreated biosolids application. Cumulative DRP runoff load in 2007 for the 15% and 30% WTR treatments resulted in significantly lower DRP loads compared to untreated biosolids and led to DRP runoff load reductions of 78% and 85% （compared to the untreated biosolids application）, respectively.

Implication of sewage sludge increased application rates on soil fertility and heavy metals contamination risk

This paper aims to assess soil fertility and risk contamination parameters in response to increased amendment rates of sewage sludge application,under semi-arid climatic conditions of Morocco,using two soil textures:soil A(clay-silty)and soil B(sandy-clay)over two years.To this end,sewage sludge and soils treatments physicochemical parameters,heavy metals content,degree of pollution and associated risks were evaluated and compared to controlled soils.The results showed that all studied parameters changed significantly(p<0.05)in a dose-dependent manner for both soils compared to the untreated control soils.Indeed,there were significant increase in organic matter(OM),total organic carbon(TOC)and nutrients content(N,P and K)of both sols as a response to increased sewage sludge amendment rates.Overall,sewage sludge application showed a positive agronomic potential for both soil and plant.However,there were concern about some heavy metals contamination risks,the results showed a gradual increase of heavy metals concentration in this order:Cu>Pb>Zn>Ni>Cd>Cr.Nevertheless,their concentrations were below the critical values established by the European Union for the agronomic use of soil.The obtained results of assessed parameters indicating SS degree of pollution and associated risks showed a low to a moderate contamination risks of heavy metals.Accordingly,environmental risks of sewage sludge application will be related to increase of heavy metals mainly in a long-term agricultural reuse.Thus,optimal management of sewage sludge application is recommended to ensure sustainability and benefits at the same time to master the contamination risks.

Field scale measurement of greenhouse gas emissions from land applied swine manure

Greenhouse gas emissions （GHGs） from swine production systems are relatively well researched with the exception of emissions from land application of manure. GttGs inventories are needed for process- based modeling and science-based regulations. Thus, the objective of this observational study was to measure GHG fluxes from land application of swine manure on a typical corn field. Assessment of GHG emissions from deep injected land-applied swine manure, Phil and reapplication in the spring, on a typical US Midwestern corn-on-corn farm was completed. Static chambers were used Ibr flux measurement along with gas analysis on a GC-FID-ECD＋ Measured gas concentrations were used to estimate GHGs flux using four different models： linear regression, nonlinear regression, first order linear regression and the revised Hutchinson and Mosier （HMR） model, respectively for comparisons.Cumulative flux esmnates after manure apphcatmn of 5.85×10 g·ha^-1（1 ha = 0.01 km） of CO2 6.60×10^1g·ha^-1 of CH4 and3.48 ×10^3g·ha^-1 N2O for the fall trial and 3.11×10^6g·ha^-1 of CO2,2.95×10^3g·ha^-1 of OH4, and 1.47×10^4g·ha^-1 N2O after the spnng reapphcation trial were observed. The N2O net cumulative flux represents 0.595% of nitrogen applied in swine manure for the fall trial.

Inactivation and risk control of pathogenic microorganisms in municipal sludge treatment:A review

The rapid global spread of coronavirus disease 2019(COVID-19)has promoted concern over human pathogens and their significant threats to public health security.The monitoring and control of human pathogens in public sanitation and health facilities are of great importance.Excessive sludge is an inevitable byproduct of sewage that contains human and animal feces in wastewater treatment plants(WWTPs).It is an important sink of different pollutants and pathogens,and the proper treatment and disposal of sludge are important to minimize potential risks to the environment and public health.However,there is a lack of comprehensive analysis of the diversity,exposure risks,assessment methods and inactivation techniques of pathogenic microorganisms in sludge.Based on this consideration,this review summarizes the control performance of pathogenic microorganisms such as enterovirus,Salmonella spp.,and Escherichia coli by different sludge treatment technologies,including composting,anaerobic digestion,aerobic digestion,and microwave irradiation,and the mechanisms of pathogenic microorganism inactivation in sludge treatment processes are discussed.Additionally,this study reviews the diversity,detection methods,and exposure risks of pathogenic microorganisms in sludge.This review advances the quantitative assessment of pathogenic microorganism risks involved in sludge reuse and is practically valuable to optimize the treatment and disposal of sludge for pathogenic microorganism control.

The Austrian node of the natural resources satellite remote sensing cloud service platform:examples of Sino-Austrian cooperation

The Austrian node of the Natural Resources Satellite Remote Sensing Cloud Service Platform was established in 2016 through a cooperation agreement between the Land Satellite Remote Sensing Application Center(LASAC),Ministry of Natural Resources of the Peoples Republic of China and the University of Vienna,Austria.Under this agreement panchromatic and multi-spectral data of the Chinese ZY-3 satellite are pushed to the server at the University of Vienna for use in education and research.So far,nearly 500 GB of data have been uploaded to the server.This technical note briefly introduces the ZY-3 system and illustrates the implementation of the agreement by the first China-Sat Workshop and several case studies.Some of them are already completed,others are still ongoing.They include a geometric accuracy validation of ZY-3 data,an animated visualization of image quick views on a spherical display to demonstrate the time series of the image coverage for Austria and Laos,and the use of ZY-3 data to study the spread of bark beetle in the province of Lower Austria.An accuracy study of DTMs from ZY-3 stereo data,as well as a land cover analysis and comparison of Austria with ZY-3 and other sensors are still ongoing.