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Most halogenated organic compounds (HOCs) are toxic and carcinogenic, hence unwanted in the environment. Several technologies exist for the treatment of both legacy and newly contaminated zones. In many contaminated subsurface environments, nano zero-valent iron (nZVI) as a reagent is the tool of choice, while palladium (Pd) as a catalyst faces technical challenges. A system comprising metallic copper and borohydride as a reducing agent (referred herein as copper-borohydride system, CBHS) provides an alternative to nZVI and Pd. This chapter presents a deeper understanding of the CBHS for the treatment of HOCs by highlighting the state of knowledge related to the i) type and classes of compounds that are treatable, ii) possible reaction pathways for their transformation, iii) specific metal activities for transformation of selected classes of HOCs, iv) influence of common water constituents on catalyst stability, and v) future perspectives regarding its application in water treatment applications. Furthermore, an up-to-date discussion is presented regarding the available techniques for the synthesis of copper nanoparticles. Based on the evaluation criteria including product selectivity patterns, amount and the fate of intermediates, and metal cost and stabilities in water, the most suitable application areas for Cu, Pd, and nZVI are presented as recommendations.

Micro (nano)plastics pollution is a noxious menace not only for mankind but also for marine life, as removing microplastics (MPs) is challenging due to their physiochemical properties, composition, and response toward salinity and pH. This review provides a detailed assessment of the MPs pollution in different water types, environmental implications, and corresponding treatment strategies. With the advancement in nanotechnology, mitigation strategies for aqueous pollution are seen, especially due to the fabrication of nanosheets/membranes mostly utilized as a filtration process. Two-dimensional (2D) materials are increasingly used for membranes due to their diverse structure, affinity, cost-effectiveness, and, most importantly, removal efficiency. The popular 2D materials used for membrane-based organic and inorganic pollutants from water mainly include graphene and MXenes however their effectiveness for MPs removal is still in its infancy. Albeit, the available literature asserts a 70- 99% success rate in micro/nano plastics removal achieved through membranes fabricated via graphene oxide (GO), reduced graphene oxide (rGO) and MXene membranes. This review examined existing membrane separation strategies for MPs removal, focusing on the structural properties of 2D materials, composite, and how they adsorb pollutants and underlying physicochemical mechanisms. Since MPs and other contaminants commonly coexist in the natural environment, a brief examination of the response of 2D membranes to MPs removal was also conducted. In addition, the influencing factors regulate MPs removal performance of membranes by impacting their two main operating routes (filtration and adsorption). Finally, significant limitations, research gaps, and future prospects of 2D material-based membranes for effectively removing MPs are also proposed. The conclusion is that the success of 2D material is strongly linked to the types, size of MPs, and characteristics of aqueous media. Future perspectives talk about the problems that need to be solved to get 2D material-based membranes out of the lab and onto the market.

Increasing environmental awareness and still countless cases of polluted environmental compartments have led to a wide range of publications on chemical remediation methods in recent years. Many of them are devoted to advanced oxidation processes (AOPs) in water, with increasing attention for the remediation of persistent pollutants in surface-, ground- and waste waters with sulfate radicals. Processes based on activation of the oxidants peroxydisulfate (PS) and peroxymonosulfate (PMS) are becoming more and more popular especially for in-situ remediation strategies for aquifers contaminated with perfluorinated alkyl substances (PFAS).In contrast to hydroxyl radicals, sulfate radicals are able to attack the carboxylate group in many PFAS. Our main focus of attention lies on the heterogeneous activation of PS for sulfate-radical generation in order to exploit pollutant enrichment at active surfaces. In the present study, the activation of PS with various iron minerals was investigated. From the pool of iron minerals tested, iron(II)-sulfide (FeS) proved to be a powerful activator for PS. A more detailed investigation of the FeS/PS system (e.g. pH dependence of the reaction, long-term performance of FeS as activator for PS and determination of radical yield and activation energy) led to the hypothesis of an activation mechanism via homolytic bond cleavage and to the assumption that FeS acts as a true catalyst with a considerable lifetime and not, as would be expected, as a reagent.Based on the experiences made, the FeS/PS system was optimized and specifically designed for degradation of PFOA (perfluorooctanoic acid), one of the most prominent PFAS representatives being in the focus of regulatory attention. Due to surface-mediated processes, the target reaction, PFOA degradation, can be carried out even in real groundwater samples, even additionally doped with typical water constituents, such as humic acid. These results are remarkable, as it is known that not only dissolved iron, but also chloride and dissolved organic matter (DOM) effectively quench free sulfate radicals. The presentation will inform about reaction products, yields and pathways under various reaction conditions. By mechanistic insight into the activation of PS via heterogeneous activation, this work breaks new ground for novel remediation approaches using PS for in-situ and ex-situ water treatment.Based on the promising lab results, a field test of the FeS/PS system, as a part of the Intraplex® technology, was conducted at a contaminated site in western Germany. The main contaminants were the perfluorinated carboxylic acids with a total concentration of 0.6 µg/L. Using a combination of permanent injection points and direct push injections, an injection transects was carried out to apply the material across the main downstream direction of the PFAS plume. The effects of the pilot test were studied by an intensive monitoring program which determined the concentration of pollutants, transformation products and hydrogeochemical parameters. Preliminary results will be presented.

Functional colloidal carbon materials find various applications, including the remediation of contaminated water and soil in so-called particle-based in-situ remediation processes. In this study, uniform and highly dispersible micro-sized carbonaceous spheres (CS) were generated by hydrothermal carbonization (HTC) of sucrose in the presence of carboxymethyl cellulose (CMC) as environmentally friendly polyelectrolyte stabilizer. In order to ensure their optimal subsurface delivery and formation of a self-contained treatment zone, a narrow size distribution and low agglomeration tendency of the particles is desired. Therefore, the obtained CS were thoroughly characterized and optimized with respect to their colloidal properties which are a crucial factor for their application as quasi-liquid sorbent. The as-prepared uniform CS are readily dispersible into single particles in water as confirmed by digital microscopy and form stable suspensions. Due to their perfectly spherical shape, particle sedimentation in aqueous suspensions is well predicted by Stokes' law. High sorption coefficients on the synthesized CS K

Hydrodechlorination (HDC) using noble-metal catalysts in the presence of H-donors is a promising tool for the treatment of water contaminated by halogenated organic compounds (HOCs). Cu is an attractive alternative catalyst to noble metals since it is cheaper than Pd, Rh, or Pt and more stable against deactivation. Cu with borohydride (BH

Groundwater is essential for the provision of drinking water in many areas around the world. The performance of the groundwater-bearing aquifer relies on the ecosystem services provided by groundwater-related organisms. Therefore, if remediation of contaminated groundwater is necessary, the remediation method has to be carefully selected to avoid risk-risk trade-offs that might impact these ecosystems. In the present study, the environmental risk of the in situ remediation agent Carbo-Iron was performed. Carbo-Iron® is a composite of zero valent nano-iron and active carbon. Existing ecotoxicity data were complemented by studies with Daphnia magna (Crustacea), Scenedesmus vacuolatus (Algae), Chironomus riparius (Insecta) and nitrifying soil microorganisms. The predicted no effect concentration of 0.1 mg/L was derived from acute and chronic ecotoxicity studies. It was compared to measured and modelled environmental concentrations of Carbo-Iron applied in a groundwater contaminated with chlorohydrocarbons in a field study and risk ratios were derived. A comprehensive assessment approach was developed further based on existing strategies and used to identify changes of the environmental risk due to the remediation of the contaminated site with Carbo-Iron. With the data used in the present study, the total environmental risk decreased by approximately 50% in the heavily contaminated zones after the application of Carbo-Iron. Thus, based on the results of the present study, the benefit of remediation with Carbo-Iron seems to outweigh its negative effects on the environment.

Background The changing climate is altering timing of key fruit ripening processes and increasing the occurrence of fruit defects. This work aimed to expand our knowledge of the genetic control of the ripening process in raspberry by examining a biennial x primocane F1 population to determine if the progeny exhibited both primocane and biennial flowering modes, which if any was dominant, and to identify QTL and genome locations associated with fruit development to understand how developmental control in this population differs from a biennial x biennial F1 population previously studied. Results The progeny from this biennial x primocane population exhibited primocane fruiting completing their lifecycle in a single season and also fruiting on second-year wood not removed in season one. QTL associated with rate of fruit development were identified on both primocane and fruiting canes with both parents impacting. Conclusions Novel QTL associated with the developmental process of primocane fruiting were identified. These in the main, differed from developmental QTL for similar developmental stages on fruiting canes (second year canes) with only one significant overlap on linkage group 6. In general, the process of development on fruiting canes overall differed from that in a biennial x biennial population, with the differences being greatest on linkage groups 3 and 6 suggesting control of development differs in the different fruiting types. Further understanding will be achieved by examining genome regions linked to QTL to allow breeding to meet climate requirements for yield stability.

Background Nanoscale zero-valent iron (nZVI) is commonly used for remediation of groundwater contaminated by chlorinated ethenes (CEs); however, its long-term reactivity and subsurface transport are limited. A novel nZVI–AC material, consisting of colloidal activated carbon (AC) with embedded nZVI clusters, was developed with the aim of overcoming the limitations of nZVI alone. Results Application of a limited amount of nZVI–AC to an oxic, nitrate-rich, highly permeable quaternary aquifer triggered time-limited transformation of CEs, with noticeable involvement of reductive dechlorination. Reductive dechlorination of CEs was dominantly abiotic, as an increase in the concentration of vinyl chloride (VC) and ethene did not coincide with an increase in the abundance of reductive biomarkers for complete dechlorination of CEs (Dehalococcoides, Dehalogenimonas, VC reductase genes vcrA and bvcA). Application of nZVI–AC under unfavourable hydrochemical conditions resulted in no dramatic change in the microbial community, the reducing effect resulting in temporal proliferation of nitrate and iron reducers only. At a later stage, generation of reduced iron induced an increase in iron-oxidizing bacteria. High concentrations and a continuous mass influx of competing electron acceptors (nitrate and dissolved oxygen) created unfavourable conditions for sulphate-reducers and organohalide-respiring bacteria, though it allowed the survival of aerobic microorganisms of the genera Pseudomonas, Polaromonas and Rhodoferax, known for their ability to assimilate VC or cis-1,2-dichloroethene. A potential for aerobic oxidative degradation of CE metabolites was also indicated by detection of the ethenotroph functional gene etnE. Conclusions This pilot study, based on the application of nZVI–AC, failed to provide a sustainable effect on CE contamination; however, it provided valuable insights into induced hydrogeochemical and microbial processes that could help in designing full-scale applications.

Arthurdendyus triangulatus (Dendy, 1894) is a land planarian native to New Zealand which has become established in the United Kingdom and the Faroe Islands during the last 60 years. The species has become prevalent and widely established in Scotland mediated by human activity mostly through the exchange of plants and associated soil. As a predator of earthworms, concerns regarding both the direct impact on earthworm abundance and diversity and the indirect impact on those birds and mammals that have earthworms as a primary dietary component led to A. triangulatus being the subject of both national and EU regulation. Whilst much is known regarding the ecology of A. triangulatus there is a significant knowledge gap regarding the genetic variability of the species. Using four DNA target regions cytochrome oxidase (CoI), elongation factor (EF), internal transcribed spacer region (ITS-1) and large subunit (LSU), we characterised the genetic variability of A. triangulatus populations across its full geographic range in Scotland and included a few populations from New Zealand, England and Northern Ireland. Two DNA regions, ITS-1 and CoI, revealed inter-population variability yielding well supported genetic structure in predominantly Scottish populations. We also identified considerable intra-specific and intra-individual heterogeneity in both ribosomal and mitochondrial regions, including the prevalence of pseudo-gene nuclear encoded mitochondrial DNA (Numt), the latter not previously reported for Platyhelminthes. Furthermore, given the presence of multiple ITS-1 haplotypes in individual specimens of A. triangulatus it is not possible to make definitive comment to support previously published findings that A. triangulatus was subjected to multiple introductions into the UK.

Genome-wide association studies (GWAS) have become a powerful tool for analyzing complex traits in crop plants. The current study evaluates the efficacy of various GWAS models and methods for elucidating population structure in potato. The presence of significant population structure can lead to detection of spurious marker-trait associations, as well as mask true ones. While appropriate statistical models are needed to detect true marker-trait associations, in most published potato GWAS, a ‘one model fits all traits’ approach has been adopted. We have examined various GWAS models on a large association panel comprising diverse tetraploid potato cultivars and breeding lines, genotyped with single nucleotide polymorphism (SNP) markers. Phenotypic data were generated for 20 quantitative traits assessed in different environments. Best Linear Unbiased Estimates (BLUEs) for these traits were obtained for use in assessing GWAS models. Goodness of fit of GWAS models, derived using different combinations of kinship and population structure for all traits, was evaluated using Quantile-Quantile (Q-Q) plots and genomic control inflation factors (λGC). Kinship was found to play a major role in correcting population confounding effects and results advocate a ‘trait-specific’ fit of different GWAS models. A survey of genome-wide linkage disequilibrium (LD), one of the critical factors affecting GWAS, is also presented and our findings are compared to other recent studies in potato. The genetic material used here, and the outputs of this study represent a novel resource for genetic analysis in potato.

Dechlorination of dichlorodiphenyltrichloroethane (DDT) as a model compound was performed with zero-valent iron (micro-ZVI and nano-ZVI) as reductant and carbonaceous adsorbents as sink and catalyst in water. DDT is rapidly converted to dichlorodiphenyldichloroethane (DDD) in direct contact with ZVI. However, up to 90% of the DDD is transformed into non-identified, most likely oligomeric products. There is no indication of dechlorination at the aromatic rings. DDT is still rapidly dechlorinated when it is adsorbed on carbonaceous adsorbents, even though ZVI particles have no direct access to the adsorbed DDT. The carbonaceous materials function as adsorbent and catalyst for the dechlorination reaction at once. From electrochemical experiments, we deduced that direct physical contact between ZVI particles and the adsorbent is essential for enabling a chemical reaction. Electron conduction alone does not effect any dechlorination reaction. We hypothesize hydrogen species (H∗) which spill from the ZVI surface to the carbon surface and initiate reductive transformations there. The role of carbonaceous adsorbents is different for different degradation pathways: in contrast to hydrodechlorination (reduction), adsorption protects DDT from dehydrochlorination (hydrolysis).

As nanoremediation strategies for in-situ groundwater treatment extend beyond nanoiron-based applications to adsorption and oxidation, ecotoxicological evaluations of newly developed materials are required. The biological effects of four new materials with different iron (Fe) speciations ([i] FerMEG12 - pristine flake-like milled Fe(0) nanoparticles (nZVI), [ii] Carbo-Iron® - Fe(0)-nanoclusters containing activated carbon (AC) composite, [iii] Trap-Ox® Fe-BEA35 (Fe-zeolite) - Fe-doped zeolite, and [iv] Nano-Goethite - ‘pure’ FeOOH) were studied using the unicellular green alga Chlamydomonas sp. as a model test system. Algal growth rate, chlorophyll fluorescence, efficiency of photosystem II, membrane integrity and reactive oxygen species (ROS) generation were assessed following exposure to 10, 50 and 500 mg L−1 of the particles for 2 h and 24 h. The particles had a concentration-, material- and time-dependent effect on Chlamydomonas sp., with increased algal growth rate after 24 h. Conversely, significant intracellular ROS levels were detected after 2 h, with much lower levels after 24 h. All Fe-nanomaterials displayed similar Z-average sizes and zeta-potentials at 2 h and 24 h. Effects on Chlamydomonas sp. decreased in the order FerMEG12 > Carbo-Iron® > Fe-zeolite > Nano-Goethite. Ecotoxicological studies were challenged due to some particle properties, i.e. dark colour, effect of constituents and a tendency to agglomerate, especially at high concentrations. All particles exhibited potential to induce significant toxicity at high concentrations (500 mg L−1), though such concentrations would rapidly decrease to mg or µg L−1 in aquatic environments, levels harmless to Chlamydomonas sp. The presented findings contribute to the practical usage of particle-based nanoremediation in environmental restoration.

For Pd-containing hydrodechlorination catalysts, coating with poly(dimethyl siloxane) (PDMS) was proposed earlier as promising protection scheme against poisoning. The PDMS coating can effectively repel non-permeating poisons (such as SO 3 2 − ) retaining the hydrodechlorination Pd activity. In the present study, the previously achieved protection efficiency was enhanced by incorporation of sulphide scavengers into the polymer. The embedded scavengers were able to bind permeating non-ionic poisons (such as H 2 S) during their passage through PDMS prior to Pd contact which ensured an extended catalyst lifetime. Three scavenger types forming non-permeable sulphur species from H 2 S – alkaline, oxidative or iron-based compounds – were either incorporated into single-layer coats around individual Pd/Al 2 O 3 particles or into a second layer above Pd-containing PDMS films (Pd-PDMS). Hydrodechlorination and hydrogenation were chosen as model reactions, carried out in batch and continuous-flow reactors. Batch tests with all scavenger-containing catalysts showed extended Pd protection compared to scavenger-free catalysts. Solid alkaline compounds (Ca(OH) 2 , NaOH, CaO) and MnO 2 showed the highest instantaneous scavenger efficiencies (retained Pd activity = 30–60%), while iron-based catalysts, such as nano zero-valent iron (nZVI) or ferrocene (FeCp 2 ), proved less efficient (1–10%). When stepwise poisoning was applied, the protection efficiency of iron-based and oxidizing compounds was higher in the long term than that of alkaline solids. Long-term experiments in mixed-flow reactors were performed with selected scavengers, revealing the following trend of protection efficiency: CaO 2 > Ca(OH) 2 > FeCp 2 . Under field-simulating conditions using a fixed-bed reactor, the combination of sulphide pre-oxidation in the water phase by H 2 O 2 and local scavenger-enhanced Pd protection was successful. The oxidizing agent H 2 O 2 does not disturb the Pd-catalysed reduction, while the PDMS-incorporated scavenger considerably extends the catalyst life in the presence of H 2 S. This work demonstrates that the scavenger-based protection strategy is an effective means to increase the resistance of PDMS-embedded Pd against permeating poisons.

There is an urgent need to develop new interventions to manage pests because evolution of pesticide resistance and changes in legislation are limiting conventional control options for farmers. We investigated β-aminobutyric acid (BABA), jasmonic acid (JA) and fructose as possible plant defence activators against grey mould disease, Botrytis cinerea , and root knot nematode, Meloidogyne incognita. We also tested Trichogramma achaeae parasitoid wasps and an antifeedant plant extract for biocontrol of the invasive tomato leafminer, Tuta absoluta . BABA and JA enhanced resistance of tomato plants to B. cinerea but neither treatment provided complete protection and the efficacy of treatment varied over time with BABA being more durable than JA. Efficacy was partly dependent on tomato cultivar, with some cultivars responding better to BABA treatment than others. Furthermore, treatment of tomato with BABA, JA and fructose led to partial suppression of M. incognita egg mass development. Biocontrol agent, T. achaeae , performance against T. absoluta could be enhanced by adjusting the rearing conditions. Both attack rate and longevity were improved by rearing the parasitoids on T. absoluta rather than on other insects. Finally, Ajuga chamaepitys extract was shown to have significant antifeedant activity against T. absoluta . Our findings suggest that there are potential new solutions for protection of crops but they are more complicated to deploy, more variable and require more biological knowledge than conventional pesticides. In isolation, they may not provide the same level of protection as pesticides but are likely to be more potent when deployed in combination in IPM strategies.

Palladium catalysts protected by embedding in polymer films proved suitable as a means to markedly prolong the life-time of the catalyst in hydrodechlorination and hydrogenation reactions for substrates from the water phase. The present work examines and summarizes optimization strategies for synthesis of embedded Pd catalysts. The polymer and the type of Pd catalyst were varied and several synthesis strategies were compared. Poly(dimethylsiloxane) (PDMS) was confirmed to best maintaining long-term stability and offering easy surface coating with highly permeable but resistant membrane layers. The generation of catalytically active Pd species in situ within the polymer (in situ synthesis) allows higher catalyst activities due to suppression of Pd agglomeration which was omnipresent when embedding unsupported nanoparticles (ex situ synthesis). Highest Pd activities were achieved with supported porous catalysts, such as Pd on γ-Al2O3. The loss in catalyst activity due to embedding compared to freely water-suspended catalysts is less pronounced for nano-sized and supported nano-sized Pd than for micro-sized Pd. Polymer embedded Pd/Al2O3 better maintains its catalytic activity than unsupported Pd nanoparticles and Pd black. The loss of activity due to PDMS embedding is a factor of 3, 190 and 1000 respectively. Higher catalyst dispersion and Pd loadings (up to 4 wt%) were obtained with condensation-vulcanizing PDMS instead of addition-vulcanizing PDMS, where the Pd load was limited due to lower Pd precursor solubility. Tailoring of the catalyst behaviour using in situ synthesized Pd-PDMS was successful by making a selection in the PDMS type, Pd loading, temperature of nanoparticle generation and type of Pd precursor.

Groundwater is essential for the provision of drinking water in many areas around the world. The performance of the groundwater-bearing aquifer relies on the ecosystem services provided by groundwater-related organisms. Therefore, if remediation of contaminated groundwater is necessary, the remediation method has to be carefully selected to avoid risk-risk trade-offs that might impact these ecosystems. In the present study, the environmental risk of the in situ remediation agent Carbo-Iron was performed. Carbo-Iron® is a composite of zero valent nano-iron and active carbon. Existing ecotoxicity data were complemented by studies with Daphnia magna (Crustacea), Scenedesmus vacuolatus (Algae), Chironomus riparius (Insecta) and nitrifying soil microorganisms. The predicted no effect concentration of 0.1 mg/L was derived from acute and chronic ecotoxicity studies. It was compared to measured and modelled environmental concentrations of Carbo-Iron applied in a groundwater contaminated with chlorohydrocarbons in a field study and risk ratios were derived. A comprehensive assessment approach was developed further based on existing strategies and used to identify changes of the environmental risk due to the remediation of the contaminated site with Carbo-Iron. With the data used in the present study, the total environmental risk decreased by approximately 50% in the heavily contaminated zones after the application of Carbo-Iron. Thus, based on the results of the present study, the benefit of remediation with Carbo-Iron seems to outweigh its negative effects on the environment.

This chapter provides an overview of NZVI types used to date for environmental restoration. The particle types are introduced systematically from bare NZVI to the manifold modifications leading to NZVI-containing composites or emulsions. Properties of these NZVI types which are important for the intended use as water treatment reagent and methods for their characterization are compiled. For each of the main NZVI groups – bare and bimetallic NZVI, polymer-modified NZVI, supported NZVI and emulsified NZVI, approved synthesis strategies and resulting NZVI properties are described.

Nanoscale zero-valent iron (nZVI) is a powerful reductant for many water pollutants. The lifetime of nZVI in aqueous environments is one of its limitations. Sulfidation of the nZVI surface by reduced sulfur species is known to significantly modify the particle properties. In the present study we examined various post-synthesis sulfidation methods applied on Carbo-Iron, a composite material where iron nanostructures are embedded in colloidal activated carbon (AC) particles. In such cases, where ZVI is surrounded by carbon, sulfidation largely inhibits the anaerobic corrosion of ZVI in water whereas its dechlorination activity was slightly increased. Even at a very low molar S/Fe ratio of 0.004 a strong decrease of the corrosion rate by a factor of 65 was achieved, while concurrently dechlorination of tetrachloroethene (PCE) was accelerated by a factor of three compared to the untreated particles. As a consequence, over 98% of the reduction equivalents of the sulfidated ZVI were utilized for the reduction of the target contaminant (33 mg L−1 PCE) under simulated groundwater conditions. In a long-term experiment over 160 days the extended life-time and the preservation of the reduction capacity of the embedded ZVI were confirmed. Reasons for the modified reaction behavior of Carbo-Iron after sulfidation compared to previously studied nZVI are discussed. We hypothesize that the structure of the carbon-embedded iron is decisive for the observed reaction behavior. In addition to reaction rates, the product pattern is vastly different compared to that of sulfidated nZVI. The triple combination of ZVI, AC and sulfur makes the composite particle very suitable for practical in-situ applications.

Nano-sized palladium (Pd) catalysts are known for their high intrinsic hydrodechlorination (HDC) activity towards many chlorinated water pollutants, converting them into non-harmful compounds. Optimization of catalyst protection by embedding various types of Pd catalysts (Pd on oxidic supports and in-situ generated Pd clusters) into poly(dimethylsiloxane) (PDMS) layers was studied together with their use in HDC reactions. The catalyst performance in standard batch and long-term experimental set-ups was used to better understand and optimize the Pd-PDMS system. The phenomenon of polymer deterioration by entrapped HDC-generated HCl is studied for various systems and found to be the main reason for limited life times of Pd-PDMS systems. Pd-PDMS composites were found to provide long-term protection from ionic catalyst poisons. This gain in prolonged catalyst protection goes along with an inevitable decrease in specific catalyst activity which is unhesitantly accepted for the benefit of a longer-lasting catalytic activity. However, when comparing the relative loss of the specific Pd activity due to embedding, it is found to be much lower for initially less active catalyst particles (e.g. a factor of 2 for Pd/Al2O3) compared to about two orders of magnitude for the highly active nanoscale Pd particles. It could be shown that embedded catalysts in continuously operated long-term set-ups have enhanced resistance and longevity compared to those tested in repeated batch-type reaction cycles. PDMS-embedded Pd/Al2O3 maintains its full initial activity up to turnover numbers of >750 (for trichloroethene as probe substance), whereas the catalyst system loses more than 50% of its initial activity for a comparable catalyst utilization (TON ≈ 750) operated in batch cycles.

An accelerated catalytic Fenton (ACF) reaction was developed based upon a multicatalysis approach, facilitating efficient contaminant oxidation at trace levels of dissolved iron. Beside the Fe(II)/H2O2 catalyst/oxidant pair for production of OH-radicals, the ACF system contains Pd/H2 as catalyst/reductant pair for fast reduction of Fe(III) back to Fe(II) which accelerates the Fenton cycle and leads to faster contaminant degradation. By this means, the concentration of the dissolved iron catalyst can be reduced to trace levels (1 mg L(-1)) below common discharge limits, thus eliminating the need for iron sludge removal, which is one of the major drawbacks of conventional Fenton processes. ACF provides fast degradation of the model contaminant methyl tert-butyl ether (MTBE, C0 = 0.17 mM) with a half-life of 11 min with 1 mg L(-1) dissolved iron, 500 mg L(-1) H2O2, 5 mg L(-1) Pd (as suspended Pd/Al2O3 catalyst) and 0.1 MPa H2, pH 3. The effects of pH, H2 partial pressure and H2O2 concentration on MTBE degradation rates were studied. Results on kinetic deuterium isotope effect and quenching studies are in conformity with OH-radicals as main oxidant. The heterogeneous Pd/Al2O3 catalyst was reused within six cycles without significant loss in activity.

Trichloroethene (TCE) dechlorination by nanoscale zero-valent iron (nZVI) in aqueous suspension was investigated in absence and presence of microscale activated carbon (AC). The TCE adsorbed within the AC micropores is available to dechlorination, although a direct contact between sorbed TCE and nZVI is ruled out. The AC functions as a mediator of redox equivalents between the external reductant and the internal sorbate. Therefore, AC plays the role of an adsorbent as well as a dechlorination catalyst driven by the reductive power of nZVI. The dechlorination product patterns in the AC–nZVI mixture and the AC-free slurry are similar, yielding ethane, ethene and ethyne as primary products. One can interpret this as spillover-like transport of mobile reactive species from the iron surface via the carbon matrix to the sorbate. In order to distinguish between transported electrons or hydrogen species, electrochemical experiments with and without the generation of nascent hydrogen (H*) were conducted. They prove the significant role of reactive hydrogen in the nZVI–AC system and favour the spillover mechanism. Ethyne and cis -DCE are the dominant products from TCE in the absence of H* species, whereas total dechlorination and hydrogenation occurred in the presence of H*, yielding ethane and ethene as the dominant primary products. The observed interplay between sorptive enrichment and chemical degradation of pollutants inside the AC pores may offer options for improved iron-carbon composite materials and reactor designs.

There is a significant knowledge gap with regard to non-filarial nematodes and their relationships, if any, with intracellular bacteria, with only sporadic reports in the literature. An intracellular bacteriaXiphinematobacter, belonging to subdivision 2 of the Verrucomicrobia, was previously reported in the ovaries of three species of the non-filarialXiphinema americanum-group of nematodes. We explored the diversity ofXiphinematobacterin 22 populations ofX. americanumsourced from six continents and conservatively have identified nine phylotypes, six of which have not previously been reported. A geographic basis to the phylotypes was noted with phylotypes A and B only found in Europe, whereas phylotypes F, G, H and I were mainly found in North America. Phylotypes C, D and E showed greater geographical variation. Sequences ofXiphinematobacterfrom this study help to inform the taxonomy of Verrucomicrobia such that the status and composition of Verrucomicrobia subdivision 2 potentially requires reflection.

Morphologically similarAphelenchoidesspp. populations extracted from rice and forage grass seeds from different geographical regions in Brazil were morphologically and molecularly characterised. Overall, the populations studied separated into two groups based on morphological and phylogenetic analyses, referred to herein as ‘Group-rice’ and ‘Group-forage’. Bayesian phylogenetic analyses of SSU, LSU and mtCOI regions strongly supported the presence of two dichotomous groups with Group-rice and Group-forage populations genetically similar toA. besseyiandA. fujianensis, respectively. This study reports the presence of a morphologically similar species toA. besseyiassociated with seeds of grasses, but genetically distinct based on three genomic regions, which our results strongly suggest to beA. fujianensis, this being a new geographical record for Brazil. Additional information regarding spicule morphology of maleA. besseyiis also reported.

Two injectable reactive and sorption-active particle types were evaluated for their applicability in permeable reaction zones for in-situ removal of herbicides (“nanoremediation”). As model substances, atrazine and bromacil were used, two herbicides frequently occurring in groundwater. In order to provide recommendations for best use, particle performance was assessed regarding herbicide degradation and detoxification. For chemical reduction, Carbo-Iron® was studied, a composite material consisting of zerovalent iron and colloidal activated carbon. Carbo-Iron reduced bromacil with increased activity compared to nanoscale zerovalent iron (nZVI). The sole reaction product, 3-sec-butyl-6-methyluracil, showed 500-fold increase in half-maximal-effect concentration (EC50) towards the chlorophyte Scendesmus vacuolatus compared to the parent compound. The detoxification based on dehalogenation confirmed the dependency of the specific mode-of-action on the carbon-halide bond. For atrazine, neither nZVI nor Carbo-Iron showed significant degradation under the conditions applied. As novel subsurface treatment option, Trap-Ox® zeolite FeBEA35 was studied for generation of in-situ permeable oxidation barriers. Both adsorbed atrazine and bromacil underwent fast unselective oxidation. The transformation products of the Fenton-like reaction were identified, and oxidation pathways derived. For atrazine, a 300-fold increase in EC50 for S. vacuolatus was found over the duration of the reaction, and a loss of phytotoxicity to non-detectable levels for bromacil.

FeS was evaluated as heterogeneous activator for peroxydisulfate (PS) with trichloroethene (TCE) chosen as model substance representing organic water pollutants prone to fast oxidation by sulfate radicals. The TCE degradation followed in most cases pseudo-first-order kinetics with a FeS-normalized maximum rate constant of k’TCE = 140 M−1min−1 (with cFeS,0 = 0.28 mM and cPS,0 = 5 mM). Sulfate radicals were determined as predominant radical species formed during PS activation by FeS by evaluation of the kinetic isotope effect for oxidation of cyclohexanes C6H12 vs. C6D12 (kC6H12: kC6D12 = 2.22). Monitoring of sulfur and iron species during the course of the reaction revealed that sulfide is rapidly oxidized, whereas Fe(II)solid is rather stable over time. The present study describes in detail the influence of the pH value on the reaction and the long-term performance of FeS as activator for PS with an optimum pH value of 5. On the basis of the radical yield from PS of 1.6 mols SO4− per mol S2O82− and the activation energy of EA = (31 ± 1) kJ mol−1 for the heterogeneous radical generation, a surface-assisted homolytic bond cleavage without simultaneous electron transfer is proposed as activation mechanism, which is contrary to the currently prevailing opinion.

Zero-valent iron (ZVI) is widely applied for reduction of chlorohydrocarbons in water. Since the dechlorination occurs at the iron surface, marked differences in rate constants are commonly found for nanoscale and microscale ZVI. It has already been shown for trichloroethene (TCE) adsorbed to activated carbon (AC) that the dechlorination reaction is shifted to the carbon surface simply by contacting the AC with highly reactive nanoscale ZVI particles. Transfer of reactive species to the adsorbed pollutant was discussed. The present study shows that even low price and very low reactive microscale ZVI can also be utilized for an effective dechlorination process. Compared to the reaction rate at the iron surface itself, an enormous acceleration of the dechlorination rate for chlorinated ethenes was observed, reaching activity levels such as known for nanoscale ZVI. When fibrous AC is brought into direct contact with microscale ZVI the iron-surface-normalised dechlorination rate constants increased by up to four orders of magnitude. This implies that the dechlorination reaction is fully transferred to the AC surface. At the same time, the anaerobic corrosion of the same material was not substantially affected. Thus, the utilization of iron's reduction equivalents towards dechlorination (dechlorination efficiency) can be considerably enhanced. A screening with various AC types showed that the extent of rate acceleration depends strongly on the surface chemistry of the AC. By means of temperature-programmed desorption, it could be shown that concentration and type of oxygen surface groups determine the redox-mediation properties. Quinone/hydroquinone groups were identified as being the main drivers for electron-transfer processes, but to some extent other redox-active groups such as chromene and pyrone can also act as redox mediators. AC overall plays the role of a catalyst rather than a reactant. The present study derives recommendations for practical application of the findings in water-treatment approaches.

After the injection of Carbo-Iron® into an aquifer contaminated with tetrachloroethene (PCE), combined chemical and microbiological contaminant degradation processes were found in a long-term study of the field site in Lower Saxony (Germany). The applied composite material Carbo-Iron, which consists of colloidal activated carbon and embedded nanoscale zero-valent iron (ZVI) structures, functioned as intended: accumulating the pollutants and promoting their reductive dechlorination. Furthermore, the particles decreased the redox potential of the groundwater due to their reaction with oxygen and to the ZVI-corrosion-induced formation of molecular hydrogen up to 190 days after the injection, the latter promoting sulphate-reducing conditions. The emergence of cis-dichloroethene (cis-DCE), which was only found in trace quantities before the injection of Carbo-Iron, together with the presence of organisms related to Sulfospirillum multivorans, Desulfitobacterium spp. and Dehalococcoides mccartyi, indicate that Carbo-Iron is also able to support microbial degradation of PCE. However, cis-DCE did not accumulate in the present case study, although it is often observed at sites with active microbial dechlorination. The results of compound-specific isotope analysis in combination with pyrosequencing data suggested the oxidative degradation of cis-DCE by an organism related to Polaromonas sp. strain JS666. Consequently, the formation of the carcinogenic degradation intermediate vinyl chloride was circumvented. Overall, the moderate and slow change of environmental conditions mediated by Carbo-Iron not only supported organohalide-respiring bacteria, but also created the basis for a subsequent microbial oxidation step.

Analysis of the genome sequence of the potato cyst nematode, Globodera pallida, has shown that a substantial gene family (approximately 300 sequences) of proteins containing a SPRY domain is present in this species. This is a huge expansion of the gene family as compared to other organisms, including other plant-parasitic nematodes. Some SPRY domain proteins from G. pallida and G. rostochiensis have signal peptides for secretion and are deployed as effectors. One of these SPRYSEC proteins has been shown to suppress host defence responses. We describe further analysis of this gene family in G. pallida. We show that only a minority (10%) of the SPRY domain proteins in this species have a predicted signal peptide for secretion and that the presence of a signal peptide is strongly correlated with the corresponding gene being expressed at the early stages of parasitism. The data suggest that while the gene family is greatly expanded, only a minority of SPRY domain proteins in G. pallida are SPRYSEC candidate effectors. We show that several new SPRYSECs from G. pallida are expressed in the dorsal gland cell and demonstrate that some, but not all, of the SPRYSECs can suppress the hypersensitive response induced by co-expression of the resistance gene Gpa2 and its cognate avirulence factor RBP-1 in Nicotiana benthamiana.

Although grass dominates most agricultural systems in the North Atlantic region (NAR), spring barley is the most important cereal and is used for animal feed and food and drink products. Recent changes in climate have resulted in warmer conditions across the NAR which have major implications for crop production. In this paper, we investigate the thermal requirement of spring barley in the region and use the results to examine the effects of recent trends in temperature and rainfall on barley cultivation, based on 11 regional meteorological sites. At these sites, between 1975 and 2015, we found significant warming trends for several months of the cropping season and significant trends for increases in the cropping season degree days (CSDD). In recent years, this has resulted in an increased proportion of years when the estimated minimum thermal requirement for barley has been met at sites above about 60°N. However, annual variations in CSDD are large and years still occur at these sites where this is insufficient. While warming could potentially allow an earlier start and later end to the cropping season, it is likely that high rainfall at maritime sites, and low rainfall at continental sites, will limit the ability of growers to benefit from this. Warming is considered to have been one of the main factors contributing to the large expansion of the area of barley cultivated in Iceland since the 1990s., Research contributing to this publication was supported by project grants from the Nordic Atlantic Cooperation (NORA; Northern cereals—new opportunities. Project number 515-005) and the Northern Periphery and Arctic Programme (Northern cereals—new markets for a changing environment; CAV Diary Number 304-8673-2014).

Field trials were carried out over a 4 year period (2004–2007) to determine the effect of agronomic factors, specifically cultivar resistance, irrigation, crop duration and chemical control (in-furrow application of azoxystrobin), on black dot development on potato tubers grown in fields where soilborne inoculum of Colletotrichum coccodes was present. In 2004, 2005 and 2006, two field trials were performed each year and in 2007, 19 mini-field trials were carried out across Scotland and England. Cultivar resistance was clearly demonstrated to be an effective method of reducing black dot disease severity on tubers (described here as the percentage of unmarketable tubers, i.e. those with symptoms covering a surface area of >10%). In the four field trials carried out in 2004 and 2005, in irrigated and fungicide-untreated plots, 43·8% of tubers of cv. Maris Piper were unmarketable, compared with 17·0% of tubers of cv. Sante. Assessments of disease development on underground plant parts (stems, stolons and roots) revealed that cultivar resistance acted only at the tuber level, as disease symptoms on other parts were often high irrespective of published disease resistance ratings. Irrigation increased the severity of disease on tubers in two trials (England 2004 and 2006), but its effect was less significant when rainfall was high. Delaying harvest by 2 weeks increased disease severity in all six trials, whilst application of azoxystrobin consistently reduced black dot severity. There were significant interactions between factors. The results clearly show how black dot disease severity can be reduced through an integrated approach to disease management.

Palladium is an efficient catalyst for hydrodechlorination (HDC) of aliphatic and aromatic chlorinated organic compounds in water. However, its applicability in water treatment processes is limited because of its sensitivity to catalyst poisons. In the present study, Pd/Al2O3 was modified by various silicone-based fillings and coatings. The modified catalysts proved to be active in the HDC of chlorobenzene with APd = 35–65 L gPd−1 min−1 vs. 570 L gPd−1 min−1 for the unprotected catalyst. It was insusceptible against sulphite as a model catalyst-deactivating ionic water constituent. However, under HDC conditions the silicone appeared to be degraded, becoming gradually permeable for sulphite. Hydrolysis of the silicone polymers, initiated and promoted by the HDC product HCl, is assumed to be responsible for the polymer ageing. Release of chloride from the coated catalyst into the bulk water phase has been revealed as a crucial step in this concept of hydrophobic catalyst protection. It could be shown that with Pd/Al2O3, HDC also proceeds in dry organic solvents such as n-hexane at significant reaction rates (APd = 18–28 L gPd−1 min−1).

Carbo-Iron – a novel composite material is presented, which consists of nanoscale zero-valent iron (nZVI) clusters on activated carbon colloids (ACC). The material is especially designed for the in situ generation of reactive zones and contaminant source removal when applied in groundwater remediation processes. This paper deals with the tailored synthesis of the composite material to create a reducing agent with properties optimized for subsurface transport of the particles and improved source affinity when compared to pure nZVI. Various iron precursors and impregnation methods are discussed with regard to their influence on the material properties. The impregnated ACCs were reduced by either H 2 or C/CO in order to achieve the desired Carbo-Iron colloids. By means of thermogravimetric analysis the optimal reduction temperatures were determined for H 2 (500 °C) and for the carbon carrier material (700 °C) as reducing agent. For stabilization of the initially generated pyrophoric highly dispersed iron nanoclusters various approaches were studied in order to generate an air-stable material without significant loss of metallic iron. Stabilization with traces of gaseous HCl gave the best results. Finally, the influence of the nZVI and residual iron oxide deposits on the sorption properties of the ACC carrier is discussed.

The vine weevil Otiorhynchus sulcatus is a major pest of horticultural crops worldwide, with root-feeding larvae causing most damage. Adult oviposition aboveground may therefore influence levels of damage as the larvae are relatively immobile after oviposition. 2 The present study investigated feeding and oviposition behaviour on red raspberry Rubus idaeus using intact plants, ensuring that choices reflected the realistic differences in cultivar appearance and chemical composition. Previous studies investigating vine weevil feeding and oviposition on other crops have used excised plant material, which may inadvertently influence behaviour. 3 Adult weevils significantly preferred to feed on particular cultivars in the choice experiment (e.g. Tulameen), although they consumed significantly more foliage (0.22-1.03 cm 2 /day) on different raspberry cultivars (e.g. Glen Moy, Glen Rosa and a wild accession) in no-choice situations. 4 In choice experiments, weevils tended to avoid laying eggs on some cul- tivars (e.g. Glen Moy and the wild accession). The number of eggs laid (1.91-4.32 eggs per day) did not, however, differ significantly between the cul- tivars in a no-choice situation. Foliar nitrogen and magnesium concentrations were positively, although weakly, correlated with the total number of eggs laid. 5 The present study highlights the importance of considering both choice and no- choice tests when assessing crop susceptibility to attack because weevils may avoid feeding on certain cultivars (e.g. Glen Moy) when given a choice, although this would cause significant damage to such cultivars if they were grown in monoculture (i.e. when there is no alternative).

The analysis of association mapping populations is frequently complicated by substructure within the population. If this is unaccounted for, it generally results in many false positive marker-trait associations. In this study, we simulate a large barley population, modelling inbreeding and selection, and compare five models for analysing marker-trait associations. One of these includes no population substructure, one includes information about geographical origin and type of barley to represent structure within the population and three use different approaches that have been proposed for estimating marker-based kinship. Kinship methods reduced the number of false positives substantially compared to the other models but none of these approaches had a clear advantage over the others. One solution is to fit more than one model and to consider as candidate associations those markers that are significant by all models. None of the approaches were very successful at detecting true associations at the lowest level of heritability considered (25%), suggesting it is important to consider power in association mapping studies to avoid missing some true associations and overestimating others.

Primers to 43 genes, including those involved in the phenylpropanoid and volatile pathways, cell wall, ethylene and polyamine metabolism, and from Prunus linkage group (LG) 6 were tested in red raspberry (Rubus idaeus) cultivars Latham and Glen Moy, and 40 were polymorphic. Thirty-seven genes were subsequently mapped in the ‘Latham’ × ‘Glen Moy’ population and were placed across all seven Rubus LG. This brings to 97 the total number of genic markers mapped in this Rubus mapping population. Fifteen genes are associated with existing quantitative trait loci for ripening, cane diseases, including yellow rust (Phragmidium rubi-idaei), cane botrytis (Botrytis cinerea), spur blight (Didymella applanata), and cane spot (Elsinoe veneta) or fruit color in R. idaeus and can be used for identifying bacterial artificial chromosome clones for physical mapping studies. A cluster of four genes from Prunus LG6 mapped together to Rubus LG3, suggesting that there may be sufficient synteny between these Rosaceae over small genomic regions that can be exploited in future studies.

Many chlorinated aromatic and aliphatic hydrocarbons dissolved in water can be rapidly and selectively hydrodechlorinated by means of Pd catalysts. However, if they appear in a complex water matrix, as is common for wastewater treatment or after soil extraction, the protection of the Pd sites against catalyst poisons may become the key step for applicability of this reaction. In the present study, Pd/Al2O3 was tested as hydrodechlorination (HDC) catalyst in various soil washing effluents. As probe compounds 3-chlorobiphenyl (3-CBP), monochlorobenzene (MCB) and trichloroethene (TCE) were chosen. Specific catalyst activities up to APd = 200 L g−1 min−1 were measured in clean water. The influence of surfactants and co-solvents was studied. In addition, soil slurry supernatant was employed as reaction medium to appraise the influence of soil co-extractants (dissolved organic matter, DOM) on the dechlorination reaction. Results show that commercially available surfactants such as Tween 80, Triton X-100, SDBS, and CTMAOH as well as methanol as co-solvent with concentrations up to 20 vol% did not strongly affect the catalyst activity. However, the catalyst performance was heavily decreased in the presence of a soil slurry supernatant (40 mg L−1 DOM). Hydrophobic coating of the catalyst by silicone polymers was successful in protecting the Pd sites against ionic catalyst poisons such as DOM and bisulphite for at least 24 h.

Palladium/magnetite nanoparticulate catalysts were developed for efficient elimination of halogenated organic pollutants from contaminated wastewater. Particle recovery from treated water can be ensured via magnetic separation. However, in worst-case scenarios, this catalyst removal step might fail, leading to particle release into the environment. Therefore, a toxicological study was conducted to investigate the impact of both pure magnetite and palladium/magnetite nanoparticle exposure upon human skin (HaCaT) and human colon (CaCo-2) cell lines and a cell line from rainbow trout gills (RTgill-W1). To quantify cell viability after particle exposure, three endpoints were examined for all tested cell lines. Additionally, the formation of reactive oxygen species was studied for the human cells. The results showed only minor effects of the particles on the tested cell systems and support the assumption that palladium/magnetite nano-catalysts can be implemented for a new wastewater treatment technology in which advantageous catalyst properties outweigh the risks.

Palladium catalysts can be used for the selective removal of halogenated organic compounds from aqueous waste via hydrodehalogenation reactions in the presence of other omnipresent constituents of industrial wastewaters. This detoxification of the water and drastic lowering of the AOX value (adsorbable organically bound halogens) can prevent the need for further cost-intensive treatment or discharge into waste incineration plants. Often, the water can then be released to municipal sewage plants. The present paper deals with a highly active, magnetically re-extractable nanoscale Pd-on-magnetite catalyst (Pd/Fe3O4) which has been developed for application in wastewater treatment processes. The study provides insight into the performance of this catalyst and gives information about its general applicability under wastewater conditions and its sensitivity towards constituents of a wastewater matrix. The catalyst can tolerate various inorganic and organic substances in relevant concentrations. Wastewaters containing a high background concentration of organic solvents can also be cleaned from halogenated pollutants. However, waters which contain heavy metals such as lead or mercury or reduced sulphur species such as sulphides need specific pre-treatments prior to Pd-catalysed hydrodehalogenation.

Pd-based catalysts have become important in environmental catalysis for their ability to hydrodechlorinate a wide range of chlorinated organic contaminants in water under ambient conditions. The success of their application in the remediation practice, e.g. for groundwater treatment, is often hindered by the sensitivity of Pd to poisoning by sulphur compounds. In this study, the stability and sulphide-induced deactivation behaviour of a highly active Pd/Al2O3 catalyst was investigated. The specific activity of Pd for the hydrodechlorination of chlorobenzene corresponds to rate coefficients up to kPd = 350 L g−1 min−1. The totally deactivated catalyst, resultant of sulphide poisoning, was regenerated with potassium permanganate. The pH value, as a key parameter which may influence the degree of deactivation as well as the efficiency of catalyst regeneration, was evaluated. Results show that in clean water the Pd/Al2O3 catalyst showed no inherent deactivation regardless of the ageing time and the pH value of the catalyst suspension. The degree of catalyst poisoning effected by 1.8–5.4 μM sulphide, corresponding to molar ratios of S:Pdsurface = 1.5–8.5, was observed to be higher under neutral and alkaline than under acidic conditions. The exposure of the catalyst to higher sulphide concentration of 14.2 μM resulted in complete catalyst deactivation regardless of the pH conditions. However, the efficacy of permanganate as oxidative regenerant for the fouled catalyst showed strong pH-dependence. A regeneration time of 10–30 min at low pH was sufficient to recover completely the high catalytic activity of Pd/Al2O3 for the hydrodechlorination reaction.