Suchergebnisse

Som et resultat af menneskelige aktiviteter er lægemidler og biocider allestedsnærværende i miljøet på sporstofniveau. Store mængder af disse stoffer, også kendt som miljøfremmede stoffer (på Engelsk XTCs: Xenobiotic Trace Chemicals), frigives dagligt fra: (i) husholdninger og sundhedsfaciliteter, som følge af indtagelse og bortskaffelse; (ii) dyrehold og tilsvarende faciliteter, som følge af dyrs indtagelse; og (iii) industrianlæg. En betydelig del af disse udledninger når frem til kommunale renseanlæg, hvor de miljøfremmede stoffer kun delvist bliver fjernet. I sidste ende udledes de miljøfremmede stoffer således til miljøet, f.eks. til ferskvandsområder der fungerer som recipienter for renseanlæg, hvor de udgør en trussel for levende organismer. Renseanlæg er blevet identificeret som en vigtig punktkilde for udledning af miljøfremmede stoffer til miljøet. På grund af det høje antal af markedsførte og forbrugt kemikalier, og de usikkerheder forbundet til prøveudtagning og analysemetoder, er der dog stadig store udfordringer forbundet med kvantificering af i hvor høj grad miljøfremmede stoffer bliver fjernet i forbindelse spildevandsrensning. Udvikling af robuste modelleringsværktøjer til at forudsige miljøfremmede stoffers skæbne i renseanlæg kan hjælpe med at overvinde denne udfordring. Men dybtgående forståelse af de mekanismer og processer, der styrer miljøfremmede stoffers fjernelse under spildevandsrensning, er stadig nødvendig. Målet med nærværende ph.d.-projekt var at udfylde huller i vores viden omkring modellering af miljøfremmed stoffers skæbne i renseanlæg og efterfølgende. Vi ville gerne forbedre forståelsen af miljøfremmede stoffers skæbne og dermed forbedre modellernes forudsigelsesevne: (i) ved processkalaen, med fokus på sorption og biologisk nedbrydning af miljøfremmede stoffer i biologiske renseanlæg; (ii) i fuldskala renseanlæg, hvor vi ville vurdere effekten af gendannelse og driften af renseanlægget på fjernelsesgraden; og (iii) i integrerede renseanlæg-landbrugssystemer. Forskellige modelleringsværktøjer, velegnede til hvert specifikt formål i undersøgelser, blev udviklet, udvidet eller anvendt innovativt. Følgende velkendte modeller blev anvendt: Activated Sludge Modelling framework for Xenobiotics (ASM-X); den generiske renseanlægsmodel SimpleTreat Activity; og den dynamiske jord-plante model til forudsigelse af kemikaliers skæbne i landbrugssystemer. Vi kombinerede eksperimentelle og modelbaserede observationer til at vurdere sorption af ioniserbare miljøfremmede stoffer til aktiveret slam og nedbrydning af miljøfremmede stoffer i "moving bed"-biofilmreaktorer (MBBRs). De fleste miljøfremmede stoffer er ioniserbare, og kan således være til stede i neutral og / eller ioniseret form i spildevand. Vi viste, at pH-betingelser, og i mindre grad, dosering af jernsalt til kemisk phosphorfjernelse, med sikkerhed påvirker faststof-væskepartitioneringen af det zwitterioniske antibiotikum ciprofloxacin i aktivt slam. Elektrostatiske interaktioner og kompleksdannelse er således dominerende sorptionsmekanismer. Vi observerede non-lineær sorption (n=0.62–1.33) under forskellige pH-, redox- og jernsalt doseringsforhold. Vi foreslog derfor en udvidelse til traditionelle sorptionsmodeller for ciprofloxacin og andre zwitterioniske miljøfremmede stoffer, som beskriver ionisering som funktion af pH og ændret sorptionspotentiale for ioniserede stoffer. Miljøfremmede stoffer findes typisk i spildevand i koncetrationsniveauer mellem ng L-1 og ug L-1, hvilket medfører at de ikke kan bruges som substrater for vækst. Vi vurderede effekten af primære metaboliske processer i MBBRs på fjernelse af miljøfremmede stoffer. Undersøgelsen blev udført ved at sammenligne kinetikken i pre-denitrificerende MBBRs kørt i enkelttrins- og tretrinskonfigurationer. Sidstnævnte konfiguration produceret en langvarig udsættelse af biofilmen for faldende belastning med COD, hvilket påvirkede kinetikken af heterotrof denitrifikation og nedbrydning af miljøfremmede stoffer. Vi fandt at nedbrydningskonstanten for en række miljøfremmede stoffer var afhængig af denitrifikationspotentialet i biofilmen, hvilket indikerer, at nedbrydning af miljøfremmede stoffer var en co-metabolisk proces. Der er beskrevet en række faktorer der påvirker fjernelsen af miljøfremmede stoffer i fuldskala renseanlæg. Relevant effekt kan tilskrives (i) faststoffers opholdstid i den biologiske rensningsproces; og (ii) dannelse af miljøfremmede stoffer via f.eks. delvis nedbrydning af menneskelige metabolitter. Mange miljøfremmede stoffer udskilles af mennesker i form af metabolitter, som efterfølgende kan omdannes til moderstoffet igen. I dette projekt vurderede vi effekten af gendannelse og faststofsopholdstid på sulfamethoxazols skæbne i fuldskala renseanlæg. Vi brugte en metode baseret på sammenligning af ASM-X modelforudsigelser med værdier fra litteraturen. Vores undersøgelse viste, at effekten af gendannelse under sekundær spildevandsrensning er bestemt af: (i) størrelsen af renseanlæggets opland, idet høj grad af gendannelse i kloaksystemet kan forventes i store oplande; og (ii) typen af opland (med eller uden hospital). Dette peger på anvendelsen af en integreret tilgang til miljøfremmede stoffers skæbne-vurdering i spildevandsssystemer (kloaksystemer og rensningsanlæg). Endvidere forudså vi og fandt forbedret fjernelse af sulfamethoxazol i renseanlæg der kører med faststofsopholdstider på mere end 16 dage. Ved faststofsopholdstider over denne værdi kan der forventes forbedrede nedbrydningskinetikker på grund af vækst i langsomtvoksende organismer (f.eks. specialiserede nedbrydere) eller på grund af blandede substratudnyttelsesstrategier. Miljøfremmede stoffer bliver som regel kun delvist nedbrudt i renseanlæg, og er derfor tilstede i udledninger fra renseanlæg og i spildevandsslammet. Udbringning af slam på marker og brug af renset spildevand eller ferskvand der modtager renset spildevand til kunstvanding af marker medfører i sidste ende optagelse af miljøfremmede stoffer i fødevareafgrøder. I dette projekt udviklede og afprøvede vi et generisk simuleringsværktøj til at forudsige miljøfremmede stoffers skæbne fra forbrug til optagelse i vinterhvede via nedbrydning i renseanlæg i en række geografiske scenarier i EU. Værktøjet kombinerede SimpleTreat Activity-modellen og den dynamiske jord-plante model, med særligt fokus på at forudsige skæbnen af ioniserbare stoffer. Ionisering har, som vist i vores første studie, store konsekvenser på faststof-væske partitioneringen, og på fordelingen ind i kornets væv. Vi udvalgte tre miljøfremmede stoffer som anvendes i store mængder, nemlig biocidet triclosan, det vanddrivende middel furosemid og antibiotikummet ciprofloxacin. Vi valgte tre reelle geografiske scenarier for områder i Den Europæiske Union og brugte gennemsnitlige forbrugsdata eller udledningsværdier fra forskellige EU-lande. Vi fandt at furosemid blev meget svagt nedbrudt i spildevandsrensning og blev signifikant akkumuleret i hvede. Optagelse af furosemid var større når udledning til jord-plante-systemet opstod via kunstvanding med ferskvand, i forhold til udbringning af slam. Set i lyset af de få eksperimentelle data indikerer vores modelberegninger et behov for uddybende undersøgelser af miljøfremmede stoffers skæbne i landbrugssystemer. Ophobning i fødevareafgrøder kan resultere i indirekte eksponering af mennesker for miljøfremmede stoffer via kosten; denne eksponering kan estimeres ved hjælp modelsimuleringer. Det præsenterede simuleringsværktøj kan således anvendes til pre-screening og prioritering af kemikalier samt til at undersøge betydningen af miljøfremmede stoffers emmisionsveje (f.eks. udbringning af gødning irrigation med behandlet spildevand) i forbindelse med akkumulering i fødevareafgrøder. ; As a result of widespread human activities, pharmaceuticals and biocides are ubiquitously present at trace levels in the environment. Large amounts of these substances, also identified as xenobiotic trace chemicals (XTCs), are released daily from: (i) households and healthcare facilities, following human consumption and disposal; (ii) husbandry and other analogous facilities, following veterinary consumption; and (iii) industrial facilities. A significant fraction of these emissions reaches municipal wastewater treatment plants (WWTPs), where XTCs undergo incomplete removal partly due to WWTP design limitations. These chemicals are thus eventually released to the environment, e.g. in freshwater bodies receiving WWTP effluents, representing a threat to living organisms. WWTPs have been generally identified as a major point source of XTC emissions to the environment. Nevertheless, due to the high number of marketed and consumed chemicals, and to the uncertainties associated to sampling and analytical methodologies, quantifying the elimination of XTCs during wastewater treatment still remains a challenge. Developing robust modelling tools to predict the fate of XTCs in WWTPs can help overcoming this challenge. However, in-depth understanding of mechanisms and processes, determining XTCs removal during wastewater treatment, is still required. This PhD thesis aimed at filling knowledge gaps in the field of XTC fate modelling during and beyond wastewater treatment. We aimed at improving the comprehension of XTC fate, and thus the predictive capabilities of fate models: (i) at process scale, with a focus on sorption and biological transformation of XTCs in biological treatment systems; (ii) in full-scale WWTPs, assessing the impact of retransformation and WWTP operation on XTC elimination; and (iii) in integrated WWTP-agricultural systems. Different modelling tools, suiting the specific purposes of our investigations, were developed, extended and/or innovatively applied. Fate models used as reference in this thesis include: the Activated Sludge Modelling framework for Xenobiotics (ASM-X); the generic WWTP model SimpleTreat Activity; and the dynamic soil-plant model for fate prediction in agricultural systems. Experimental and model-based observations were combined to assess sorption of ionizable XTCs onto activated sludge and XTC biotransformation in moving bed biofilm reactors (MBBRs). Most XTCs are in fact multispecies chemicals, being present in neutral and/or ionized form in wastewater. We demonstrated that pH conditions and, to a lesser extent, iron salt dosing for chemical phosphorus removal can significantly affect solid-liquid partitioning of the zwitterionic antibiotic ciprofloxacin onto activated sludge. Electrostatic interactions and complexation are thus dominating sorption mechanisms. Under a range of pH, redox and iron salt dosing conditions, non-linear sorption (n=0.62–1.33) was observed. Extensions to traditional partitioning models were accordingly proposed for ciprofloxacin and other zwitterionic XTCs, accounting for: (i) high non-linearity of XTC sorption; or (ii) ionization with changing pH and different sorption potential of ionized species. Furthermore, XTCs are typically present in ng L-1 to µg L-1 concentrations in wastewater, being referred to as non-growth substrates, and their biological degradation can be associated with microbial growth processes. In this PhD thesis, we assessed the influence of primary metabolic processes on XTC biotransformation in MBBR biofilm. Our investigation was performed by comparing biotransformation kinetics in pre-denitrifying MBBRs operated in single-stage and three-stage configurations. The latter configuration produced a prolonged biofilm exposure to organic electron donor (COD) loading and complexity tiered by segregated and integrated biofilm reactors, which significantly influenced kinetics of heterotrophic denitrification and XTC biotransformation. Biotransformation rate constants for a number of non-recalcitrant XTCs were found correlated to the denitrification potential of MBBR biofilm, suggesting that XTC degradation occurred via microbial co-metabolism. In addition, enhanced biotransformation kinetics was shown for a number of XTCs (sulfamethoxazole, erythromycin, atenolol) as compared to previous findings for conventional activated sludge. A number of factors have been described to influence the elimination of XTCs in full-scale WWTPs. Specifically, relevant impact was attributed to (i) solid residence time (SRT), at which biological treatment is operated; and (ii) the formation of XTCs due to, e.g., deconjugation of human metabolites. Many XTCs are in fact excreted by humans in the form of conjugates, which can undergo biotic retransformation to parent chemicals. In this PhD thesis, we specifically assessed the influence of retransformation processes and SRT on the fate of sulfamethoxazole in full-scale WWTPs. A methodology based on the comparison of ASM-X predictions and literature data was used. We demonstrated that the impact of retransformation during secondary wastewater treatment is determined by: (i) the size of WWTP catchments, with major in-sewer retransformation expected in large catchments; (ii) the type of catchment (hospital or urban catchment). This evidence accordingly suggests an integrated approach to XTC fate assessment in wastewater systems (sewer networks and WWTPs). Furthermore, improved elimination of sulfamethoxazole was found and predicted in WWTPs operated at SRT greater than 16 d. Beyond this critical SRT, enhanced biotransformation kinetics may occur due to the enrichment of slow-growing organisms (e.g., specialist degraders) or mixed substrate utilization strategies. This finding supported our experimental evidence of enhanced sulfamethoxazole biotransformation kinetics in denitrifying MBBRs. As a result of incomplete biodegradation in WWTPs, XTCs persist in effluents and sewage sludge. Reuse of municipal biosolids and treated wastewater or use of freshwater for agricultural purposes eventually leads to XTC uptake into food crops. In this PhD thesis, we developed and tested a generic simulation tool to predict the fate of XTCs from consumption, through wastewater treatment and eventually to the uptake by winter wheat for a number of geographical scenarios in the European Union. The tool combined was specifically addressed for fate prediction of ionizable XTCs (the biocide triclosan, the diuretic furosemide and the antibiotic ciprofloxacin). Furosemide was found rather persistent to wastewater treatment (removal efficiency ≤ 40%) and to further undergo significant accumulation in wheat. Uptake of furosemide was predicted to increase (+20% of emissions to soil) when emissions to the soil-plant system occurred via freshwater irrigation, as compared to soil amendment with biosolids. Due to the scarce availability of experimental data, our model predictions indicate the need of deepening investigations of XTC fate in agricultural systems. Accumulation in food crops may result in indirect human exposure to XTCs via dietary intake, which can be eventually estimated using model predictions. The presented simulation tool can thus be used for pre-screening and priority setting of chemicals, and to explore the impact of additional XTC emission pathways (e.g., manure application, irrigation with reclaimed WWTP effluent) in terms of food crop accumulation.

In the past 15 years, China has emitted the most carbon dioxide globally. The overuse of chemical fertilizer is an essential reason for agricultural carbon emissions. In recent years, China has paid more and more attention to financial support for agriculture. Therefore, understanding the relationship between chemical fertilizer use, financial support for agriculture, and agricultural carbon emissions will benefit sustainable agricultural production. To achieve the goal of our research, we selected the panel data of 30 provinces (cities) in China from 2000 to 2019 and employed a series of methods in this research. The results demonstrate that: the effect of chemical fertilizer consumption on agricultural carbon emissions is positive. Moreover, financial support for agriculture has a significantly positive impact on reducing carbon emissions from agricultural production. In addition, the results of causality tests testify to one−way causality from financial support for agriculture to carbon emissions from agricultural production, the bidirectional causal relationship between chemical fertilizer use and financial support for agriculture, and two−way causality between chemical fertilizer use and agricultural carbon emissions. Furthermore, the results of variance decomposition analysis represent that financial support for agriculture will significantly affect chemical fertilizer use and carbon emissions in the agricultural sector over the next decade. Finally, we provide several policy suggestions to promote low−carbon agricultural production based on the results of this study. The government should uphold the concept of sustainable agriculture, increase financial support for environmental−friendly agriculture, and encourage the research and use of cleaner agricultural production technologies and chemical fertilizer substitutes.

Introduction to legal challenges in agriculture, agrochemicals, and agribusiness -- An historical view from ten thousand feet : how has agriculture been impacted by legal changes over the years? -- How the U.S. Constitution impacts agriculture -- Continuing evolution of the coordinated framework : implications for agricultural biotechnology -- Clearing freedom to operate for new agrochemical products -- Patents for agrochemical inventions must satisfy the utility requirement under the patent law -- Strengthen your patents on agricultural inventions by appealing the patent examiner's rejections to the patent trial and appeal board -- Introduction to agrochemical patent term extension in Europe -- NAICC advocating for research and crop consultants -- Historical perspective on : regulations in changing legal environments.

Certain types of pesticides are widely used in agriculture in all parts of the world due to their relatively low cost, broad spectrum of activity, and high efficiency. These pollutants contaminate not only the surrounding soils and water but, in many cases, also enter into the drinking water. The Handbook of Research on the Adverse Effects of Pesticide Pollution in Aquatic Ecosystems provides emerging research exploring the theoretical and practical aspects of the prevention of accumulation of toxic pollutants such as agrochemicals and organochlorine pesticides in aquatic ecosystems and applications within ecology and agriculture. Featuring coverage on a broad range of topics such as pesticide monitoring, metabolites, and risk assessment, this book is ideally designed for scientists, researchers, engineers, policymakers, agricultural specialists, industrialists, academicians, and students seeking current research on the risks of water contaminants in small ecosystems

"Global population is expected to increase 30% by the year 2050. One pressing issue that comes with increasing population is food security. Adequate food production is a key component of food security, and it involves increasing agricultural production and efficiency while diminishing the environmental impact on humans. This challenge has inspired the development of new solutions and the application of advanced methods to evaluate current agricultural practices. Research in the sustainable food production space is currently flourishing. This eBook focuses on a number of these innovations and will be relevant to researchers and students in food science, chemistry, entomology and agricultural engineering."--

Front Cover -- About Island Press -- Subscribe -- Title Page -- Copyright -- Dedication -- Contents -- Introduction: Creve Coeur -- Chapter 1: Getting Dirty -- Chapter 2: Railroad Avenue -- Chapter 3: Making a Case -- Chapter 4: Joining Forces -- Chapter 5: Going After Goliath -- Chapter 6: In the Interests of Justice -- Chapter 7: Corporate Secrets -- Chapter 8: A Risky Plan -- Chapter 9: Just Past Midnight -- Chapter 10: Lizard Man -- Chapter 11: A Question of Science -- Chapter 12: San Francisco Showdown -- Chapter 13: The Cavalry -- Chapter 14: Staying Alive -- Chapter 15: The Trial Begins -- Chapter 16: For the Defense -- Chapter 17: An Unusual Case -- Chapter 18: Fighting until the Last Breath -- Chapter 19: The Last Word -- Chapter 20: Verdict -- Epilogue: A Leaf That Doesn't Die -- A Note on Sources -- Acknowledgments -- Index.

International audience ; In South America, public policies take a strong interest in alternative technologies to agricultural chemical inputs (pesticides and fertilisers). Some South American countries support biological inputs, also known as bioinputs, through national incentive programmes and regulatory changes. Argentina, Brazil and Colombia are playing a leading role. However, the intention behind this promotion of bioinputs is not to break with industrial agricultural production models, from which States derive a large part of their tax income through exports. Rather, the goal is to foster coexistence between chemical and biological inputs in the context of a transition towards the bioeconomy. In this sense, the promotion of bioinputs meets the expectations of many South American farmers, as well as those of the agricultural inputs industry, which over the last few decades has diversified into these technologies. But these industrial dynamics are counter to certain farmers' movements that defend on-farm production of biological inputs.

International audience ; In South America, public policies take a strong interest in alternative technologies to agricultural chemical inputs (pesticides and fertilisers). Some South American countries support biological inputs, also known as bioinputs, through national incentive programmes and regulatory changes. Argentina, Brazil and Colombia are playing a leading role. However, the intention behind this promotion of bioinputs is not to break with industrial agricultural production models, from which States derive a large part of their tax income through exports. Rather, the goal is to foster coexistence between chemical and biological inputs in the context of a transition towards the bioeconomy. In this sense, the promotion of bioinputs meets the expectations of many South American farmers, as well as those of the agricultural inputs industry, which over the last few decades has diversified into these technologies. But these industrial dynamics are counter to certain farmers' movements that defend on-farm production of biological inputs.

International audience ; In South America, public policies take a strong interest in alternative technologies to agricultural chemical inputs (pesticides and fertilisers). Some South American countries support biological inputs, also known as bioinputs, through national incentive programmes and regulatory changes. Argentina, Brazil and Colombia are playing a leading role. However, the intention behind this promotion of bioinputs is not to break with industrial agricultural production models, from which States derive a large part of their tax income through exports. Rather, the goal is to foster coexistence between chemical and biological inputs in the context of a transition towards the bioeconomy. In this sense, the promotion of bioinputs meets the expectations of many South American farmers, as well as those of the agricultural inputs industry, which over the last few decades has diversified into these technologies. But these industrial dynamics are counter to certain farmers' movements that defend on-farm production of biological inputs.

The fundamental aspects (water control, high-yielding seed varieties and chemical fertilizer) relating to the technical reform of post-Mao agriculture are discussed in this contribution. Decline in state financial emhasis on water construction. Extremely rapid rate of growth of chemical fertilizer use during the post-Mao period. (DÜI-Sen)

In South America, public policies take a strong interest in alternative technologies to agricultural chemical inputs (pesticides and fertilisers). Some South American countries support biological inputs, also known as bioinputs, through national incentive programmes and regulatory changes. Argentina, Brazil and Colombia are playing a leading role. However, the intention behind this promotion of bioinputs is not to break with industrial agricultural production models, from which States derive a large part of their tax income through exports. Rather, the goal is to foster coexistence between chemical and biological inputs in the context of a transition towards the bioeconomy. In this sense, the promotion of bioinputs meets the expectations of many South American farmers, as well as those of the agricultural inputs industry, which over the last few decades has diversified into these technologies. But these industrial dynamics are counter to certain farmers' movements that defend on-farm production of biological inputs.