The use of reclaimed water in agriculture is a potential solution to regional water shortages. A controlled lysimeter study investigated the impact of irrigation with reclaimed water on the soil's water and nutrient balance, and the potential impact on drainage water quality for groundwater recharge. Planted and unplanted lysimeters with defined soil profiles were irrigated with reclaimed or tap water for 12 months (August 2024 to August 2025). The reclaimed water was obtained from a membrane bioreactor. Water balance (precipitation, irrigation and potential evapotranspiration) and drainage water formation were recorded and sampled weekly. The analyses included physico-chemical parameters (pH, electrical conductivity, total bound nitrogen, nitrate, nitrite, and ammonium nitrogen), anions (chloride, fluoride, sulfate), and 21 organic micropollutants. In the planted lysimeters, electrical conductivity increased notably, especially during dry summer periods, suggesting evapotranspiration effects and altered flow paths within the root zone. Conversely, nitrogen concentrations in the drainage water from the planted lysimeters were substantially lower than in the unplanted lysimeters, which is consistent with plant uptake and potentially enhanced microbial conversion in the rhizosphere. In summary, both vegetation and water type markedly affected drainage water quality, with clear differences between reclaimed and tap water as well as strong seasonal effects. The results suggest that when assessing irrigation with reclaimed water, site- and management-specific conditions and vegetation-related differences in drainage water quality and groundwater recharge rates must be considered.

The effect of boric acid post-modification on [Al]ZSM-5 zeolites is investigated. Boric acid modification reduces surface areas, and high loadings lead to agglomeration of crystals. 11B MAS NMR spectroscopy indicates boron isomorphously substituted into the framework if 1.5 wt% boric acid is applied, while above 5 wt% loading additionally surface bound BT1 species and, increasingly, boric acid deposits BT0 are found. The Brønsted acid site (BAS) density decreases with boric acid loading. 1H MAS NMR spectroscopy after acetonitrile-d3 loading reveals a similar BAS strength as the parent, thus BAS are associated with bridging Si(OH)Al from the parent's structure. A loading with trimethylphosphine oxide (TMPO) is sensitive to weaker Lewis acid sites (LAS). A subsequent hydration changes the nature of water-accessible boric acid surface species. Conversion of methanol, ethanol, or ethene over boric acid-modified MFI was tested. For 1.5 wt% loading, an increased BTEX content and lifetime in ethanol conversion was observed, while other modified catalysts were outperformed by the unmodified parent. Most boron is removed after catalytic application. It is concluded that the introduced weak surface acidity and the introduced LAS density could render the modification method interesting for synthesizing new adsorbents operated at moderate conditions.

Three zeolite catalysts with comparable amounts of aluminum and/or boron ([Al]ZSM-5, [B,Al]ZSM-5, and [B]ZSM-5) are herein synthesized. Water (H2O), ammonia (NH3), acetonitrile-d3 (ACN), and trimethylphosphine oxide (TMPO) are applied as probe molecules to investigate the acidity of the respective materials in combination with 11B, 27Al, and 29Si MAS NMR spectroscopy. Ammonia is not protonated to ammonium on Si(OH)B groups and only LAS-bound ammonia persists desorption. Thus, ammonia gives a realistic, quantitative picture of the present acid sites. ACN interacts only with Si(OH)Al as desired. The strong base TMPO results in a misleading, not quantifiable picture. Subsequent hydration is unsuited to distinguish BAS and LAS densities. The samples were catalytically tested in the conversion of methanol, ethanol, and ethylene. [B]ZSM-5 is unreactive in hydrocarbon formation due to absence of BAS, instead LAS are present. The mixed [B,Al]ZSM-5 shows a decreased lifetime in MTO conversion compared to the [Al]ZSM-5, due to LAS presence. A sometimes reported superior reactivity of [B,Al]ZSM-5 catalysts is thus explained primarily by an optimized BAS density.

Per- and polyfluoroalkyl substances (PFAS) are highly persistent and potentially toxic chemicals that have been found in many drinking water resources worldwide. Increasingly stringent limits for these substances require advanced treatment concepts to remove these substances during drinking water treatment. Today, the majority of treatment systems for PFAS removal rely on granular activated carbon (AC) or ion exchange resins (IX), whose capacities are often limited by competitive adsorption of dissolved organic matter. In this study, a screening of six AC, five PFAS-specific IX, and seven alternative adsorbents was performed using equilibrium jar tests. The removal of 12 selected PFAS was compared to the removal of 16 other non-PFAS organic micropollutants. Dissolved organic matter competition was investigated using size exclusion chromatography with online organic carbon and UV254 detection. In addition, AC were characterized by determination of the pH at the point of zero charge, cation and anion exchange capacity, and surface oxygen groups. While IX appear to be the best choice for short-chain PFAS removal, AC allows for broader removal of organic micropollutants, and bentonite-based surface modified clays allow for highly selective PFAS removal with very low DOM competition. The data also show that the removal of acesulfame might be used as an indicator for removal of some PFAS, allowing an initial selection of activated carbon or ion exchange resin in the absence of PFAS data. Carbonyl surface oxygen groups determined with thermogravimetric analysis coupled to Fouriertransform infrared spectroscopy served as best predictor for organic micropollutant removal by AC.

The amount of BTEX aromatics obtained from the conversion of ethanol (ETA) is increased by combining ZSM-5 catalysts having optimum acidity with desilication and zinc ion exchange. Zinc leads to preferred dehydrogenation instead of hydrogen transfer. It decreases the share of paraffin products and increases BTEX contents (up to SBTEX = 50%) at the cost of lifetime. The latter can be increased via desilication. An ethylene feed increases lifetime and BTEX production as result of oxygenate absence. Combination of improvements resulted in a C2 conversion capacity of 206 g g-1 and a total yield of BTEX aromatics of 31.6 g g-1, which is about a factor of 2-3 times better than the respective values found for microporous, mesoporous, or microporous Zn-exchanged materials. In situ UV/vis spectra reveal that desilicated samples coke significantly slower than microporous samples, whereas Zn exchange supports the formation of coke. Thus, by a clever combination of suitable post-modifications, a significantly higher BTEX production from the primary source ethanol can be achieved.

Per- and polyfluoroalkyl substances (PFAS), known for their exceptional stability and hydrophobic properties, have become prominent environmental contaminants due to their persistence and toxicity. This review provides a comprehensive analysis of PFAS occurrence in groundwater and surface waters, their degradation by various microbial species and the effectiveness of different adsorbents in PFAS removal. Microbial degradation is a costeffective and environmentally friendly method for PFAS removal, with aerobic biotransformation being more widely studied. Microbial strains, including Acidimicrobium sp. A6, Pseudomonas, and Gordonia sp. showed sustainable reduction (up to 99 %) in PFAS concentrations. Under aerobic and anaerobic conditions, microbial mechanisms differ significantly, requiring specific microbial strains or engineered systems to break the strong C-F bonds. Various adsorbents, such as carbonaceous materials, ion exchange resins, and other synthetic materials, have been used to remove PFAS from water. Positively charged adsorbents were more effective in removing PFAS than neutral or negatively charged ones. Ion exchange resins outperform other adsorbents in removing both long and short-chain PFAS. This review outlines significant research needs, including the need to understand the complex interactions between dissolved organic matter and PFAS removal, as well as the potential of advanced materials to improve adsorption processes. Future research should focus on scalable, cost-effective, and environmentally sustainable methods to reduce PFAS contamination and provide safer water resources for future generations.

In Brandenburg, Germany, 8% of households rely on single-household cesspits for wastewater collection. This study analysed the chemical and microbial characteristics of wastewaters from 12 single-household cesspits and pit lorry samples to assess their suitability for water reuse. The analyses include physico-chemical parameters (pH, electrical conductivity, chemical and biochemical oxygen demand, total nitrogen, ammonium, phosphorus), 11 heavy metals, 67 organic trace substances, and bacteria concentrations. Measurements showed strong similarity across single-household cesspits for pH, electrical conductivity, Shannon Index and Richness of the microbial communities. In contrast, there was high variability across cesspits for oxygen demand, nitrogen, phosphorus, heavy metals, organic trace substances and total and damaged bacteria concentrations. Comparison with municipal wastewater showed that cesspits contained higher concentrations of organic and inorganic pollutants, which may be related to household-specific use patterns and limited dilution by wastewater from other sources. Physico-chemical analyses indicate that cesspits contained mainly easily degradable organic substances. The high variability of wastewater from cesspits points to the need for flexible treatment approaches. The results enhance the understanding of composition of wastewater from decentralised sources in Central Europe and support efforts towards sustainable water management and the development of adaptable treatment solutions for different wastewater compositions.

Herein, we apply three different copper-exchanged materials (Na-[Al]SBA-15, silica, Na-MCM-22) as hosts for a direct synthesis of Cu-I(1,1 '-bis(diphenylphosphino)ferrocene = dppf) complexes in cationic ion exchange position. Using P-31 MAS NMR spectroscopy, we show that identical complexes as after ion exchange are generated if the solids are applied as reactants directly. The homogeneity of copper exchanges is evaluated by EDX spectroscopy. Both Cu-I and Cu-II result in the formation of complexes, thereby oxidizing dppf. Cu-particles were not reactive. Optimized conditions for a maximized complex formation are identified applying quantitative P-31 MAS NMR spectroscopy and ICP-OES. Only accessible copper in cationic position of the solids forms the complexes. This enables a quantification of the amount of copper in mesopores vs. the total copper amount. Thus, besides a new synthesis of the complex a suitable method for quantitative elucidation of the location of copper cations is demonstrated herein.

A fast method for microplastic detection is thermal extraction desorption-gas chromatography/mass spectrometry (TED-GC/MS), which uses polymer-specific thermal decomposition products as marker compounds to determine polymer mass contents in environmental samples. So far, matrix impacts of different environmental matrices on TED-GC/MS performance had not yet been assessed systematically. Therefore, three solid freshwater matrices representing different aquatic bodies with varying organic matter contents were spiked with a total of eight polymers. Additionally, for the first time, the two biodegradable polymers polybutylene adipate terephthalate (PBAT) and polylactide (PLA) were analysed using TED-GC/MS. The methodological focus of this work was on detectability, quality of signal formation as well as realisation of quantification procedures and determination of the limit of detection (LOD) values. Overall, TED-GC/MS allowed the unambiguous detection of the environmentally most relevant polymers analysed, even at low mass contents: 0.02 wt% for polystyrene (PS), 0.04 wt% for the tyre component styrene butadiene rubber (SBR) and 0.2 wt% for polypropylene (PP), polyethylene (PE) and PBAT. Further, all obtained LOD values were increased in all matrices compared to the neat polymer without matrix. The LOD of the standard polymers were increased similarly (PS: 0.21-0.34 mu g, SBR: 0.27-0.38 mu g, PP: 0.32-0.36 mu g, PMMA: 0.64-1.30 mu g, PET: 0.90-1.37 mu g, PE: 3.80-6.99 mu g) and their decompositions by radical scission processes were not significantly influenced by the matrices. In contrast, matrix-specific LOD increases of both biodegradable polymers PBAT (LOD: 1.41-7.18 mu g) and PLA (0.84-20.46 mu g) were observed, probably due to their hetero-functional character and interactions with the matrices. In conclusion, the TED-GC/MS performance is not solely determined by the type of the polymers but also by the composition of the matrix.

ABSTRACT Photochemical and advanced oxidation processes (AOPs) are promising options to simultaneously disinfect wastewater treatment plant (WWTP) effluent and degrade organic micropollutants (OMPs). In the present study, kinetic experiments with UV alone (254 or 254+185 nm) and the combination of UV and hydrogen peroxide (H2O2) as an AOP were conducted in WWTP effluent (with and without ultrafiltration) to assess the degradation of 24 OMPs, 13 of which were examined for the first time, in a flow-through batch reactor setup. Four parameters were systematically varied to quantify their impacts on OMP degradation: H2O2 concentrations, UV source, water matrix, and flow rate. Most of the studied OMPs (e.g., trimethylammonium, 1,3-di-o-tolylguanidine, carbamazepine) were only significantly degraded in the presence of UV radiation and H2O2. The highest pseudo-first-order rate constants were found for diclofenac, acesulfame, diatrizoate, and sulfamethoxazole. The experiment with the highest degradation also showed the strongest abatement of UV absorbance at 254 nm. Only three of the 24 substances (cyanoguanidine, melamine, and oxipurinol) were not degraded; UV alone even increased their concentrations. Overall, upgrading a UV disinfection to an AOP using H2O2 allows the degradation of a wide range of OMPs, making it an interesting process for water reuse.

A Pt-ZSM5 catalyst, coked during propane dehydrogenation and regenerated with lean air, was studied by various in-situ and ex-situ methods. A newly developed isothermal ceramic flat-bed reactor with inert surfaces is described and used in the experiments. Comparative measurements successfully demonstrated that temperature alone has no effect on the catalyst and that changes in conversion and selectivity are due to coke formation. Nuclear magnetic resonance (NMR) studies using triphenylphosphine probe molecules of activated and deactivated samples showed the localization of the Pt clusters inside and outside the zeolite pores. It was shown that the Pt clusters are mainly located inside the zeolites and that the mobilization of Pt by contact with oxygen leads to permanent aging. A Pt-ZSM5 catalyst, coked during propane dehydrogenation and regenerated with air, was investigated. For this, a newly developed isothermal ceramic flat-bed reactor was described and applied. It was demonstrated that the Pt clusters are located inside the zeolite pores. Mobilization of Pt by oxygen contact leads to permanent aging. image

For Brandenburg, a region in Germany with increasing water shortage and drought events, water reuse can counteract competition scenarios between drinking water supply, agricultural irrigation, and industrial use. Centralized and decentralized sources for reclaimed water are found to potentially substitute 245 or 28% of irrigation water, respectively, in agriculture production in Brandenburg. For such a reuse scenario, the fate of organic micro-pollutants is examined for diatrizoate (DZA) and carbamazepine (CBZ). Retention in local sandy soil and transfer into roots and leaves of arugula are analyzed in lysimeter studies and greenhouse pot experiments. Vertical transport was found for DZA and accumulation in or on arugula roots with a root concentration factor of 1,925 +/- 34% but a low bioconcentration factor due to intrinsic molecule properties. CBZ was not found to be mobile in the sandy soil but accumulates in arugula roots and leaves by factors of 70 +/- 7% and 155 +/- 12%, respectively. Further research on potential plant uptake and groundwater enrichment for more substances is highly recommended as well as tertiary wastewater treatment prior to water reuse. HIGHLIGHTS center dot The volume of treated wastewater exceeds irrigation water by a factor of 2.5 in Brandenburg. center dot Water reuse could reduce competition between drinking water supply in the industry and agriculture. center dot Organic micro-pollutant pathways for sandy soil to groundwater and to plants are assessed. center dot Carbamazepine did not reach 10 cm depth in lysimeter studies probably due to acidic soil pH. center dot Diatrizoate obtained very high concentrations in arugula roots but were low in leaves.

We identify favorable parameters for the formation of aromatics from ethanol-based feeds over ZSM-5. An ethanol partial pressure of 0.3 bar, a reaction temperature of similar to 700 K, a low weight hourly space velocity (WHSV), and a high Bronsted acid site density increase the content of aromatics, in the latter case, on the expense of lifetime. The aromatic fraction composition changes with the WHSV and nSi/nAl ratio. Water cofeed increases the content of aromatics in the C2:H2O stoichiometry of 1:0.5 (equals diethyl ether as feed) but decreases it if this is exceeded. Diethyl ether and ethylene lead to more aromatics than ethanol feed. The lifetime until deactivation increases in the order ethanol < diethyl ether < ethylene. This points at different reaction and/or deactivation mechanisms in converting the three feeds. Thus, a water-poor feed effectively improves the catalyst lifetime and productivity in the ethanol conversion to aromatics.

Herein, desilication in increasingly harsh conditions was used to introduce mesopores into two different industrial ZSM‐5 catalysts (Si/Al ratio 11 or 29). For desilicated samples, increasing BET surface areas, mesopore volumes, and Si(OH) densities were noted. Brønsted acid site (BAS) densities increased upon desilication, as formerly inaccessible BAS in blocked pores became available, while the strength of the BAS was maintained upon desilication. Using KOH instead of NaOH as desilication agent can increase the mesopore volume generated per mass loss. The correlations between desilication strength and properties were largely determined by the parent Si/Al ratio. In general the introduced mesopores increased lifetimes in the ETA conversion, while additional Si(OH) groups introduced by desilication reduce the lifetime again. The lifetime is thus determined by a complex interplay of BAS density, improved reactant transport by introduced mesopores and Si(OH) density. There were no additional aromatics formed in desilicated samples during the conversion of ethanol and the samples were, in terms of aromatic yield, outperformed by a microporous parent. However, as result of longer lifetimes less ethanol was lost due to coke formation. It is concluded that desilication should be combined with other post‐modifications to increase aromatic production and lifetime.

Organometallic complexes are frequently deposited on solid surfaces, but little is known about how the resulting complex-solid interactions alter their properties. Here, a series of complexes of the type Cu(dppf)(Lx)+ (dppf = 1,1'-bis(diphenylphosphino)ferrocene, Lx = mono- and bidentate ligands) were synthesized, physisorbed, ion-exchanged, or covalently immobilized on solid surfaces and investigated by 31P MAS NMR spectroscopy. Complexes adsorbed on silica interacted weakly and were stable, while adsorption on acidic γ-Al2O3 resulted in slow complex decomposition. Ion exchange into mesoporous Na-[Al]SBA-15 resulted in magnetic inequivalence of 31P nuclei verified by 31P-31P RFDR and 1H-31P FSLG HETCOR. DFT calculations verified that a MeCN ligand dissociates upon ion exchange. Covalent immobilization via organic linkers as well as ion exchange with bidentate ligands both lead to rigidly bound complexes that cause broad 31P CSA tensors. We thus demonstrate how the interactions between complexes and functional surfaces determine and alter the stability of complexes. The applied Cu(dppf)(Lx)+ complex family members are identified as suitable solid-state NMR probes for investigating the influence of support surfaces on deposited inorganic complexes.

We herein conduct the first H-1 and C-13 MAS NMR investigations that explore the formation of surface methoxy groups (SMG) on defect Zr(OH) groups of UiO-66 metal-organic frameworks. Loading acetone-2-C-13 indicates that UiO-66 contains weakly acidic Zr(OH) groups. These react at room temperature with adsorbed methanol-C-13 to SMG. Quantitative formation of SMG and methanol removal are achieved at 473 K. H-1-C-13 heteronuclear correlation proves close proximity between persistent, inaccessible Zr(OH) groups at delta(1H) = 1.2 ppm and SMG groups. SMG react with water to free methanol; however, the SMG cannot methylate hydrocarbons like toluene. This is explained by the weak acidity of Zr(OH) groups hosting the SMG. The 0.17 mmol/g SMG that was formed corresponds to 13% missing linkers, in good agreement with 11% missing linkers calculated from TGA. Thus, the formation and quantification of SMG by C-13 MAS NMR spectroscopy are demonstrated as alternative measures for the amount of Zr(OH) in defects.

Crystal size is a key parameter of zeolites applied as catalysts. Herein, ZSM-5 crystals with similar physicochemical and acid properties, few defects, and aluminum exclusively in tetrahedral coordination are synthesized and the influence of the crystal size on the MTO and ETA conversion is investigated. Short olefins are the main products of the MTO conversion, whereas larger olefins and aromatics dominate the products after ETA conversion. In the case of both feeds, an increased crystal size decreases the catalyst’s lifetime. The MTO conversion over larger ZSM-5 altered the product distribution, which was not the case for the ETA conversion. The reason is that the instantly available aromatics during ETA conversion lead to fast coking and zeolite crystals only active in the outer layers. Thus, the different reactivity of different-sized ZSM-5 is direct proof of a different conversion mechanism for both alcohols.

Control of reaction conditions, short residence times and completely inert surfaces are of major importance when studying aging mechanisms by soot formation. The use of ceramics as reactor material in combination with a special reactor design allows control over industrially relevant reaction conditions (T-max = 1100 degrees C, t(Residence) = 50 ms) and sample shapes while avoiding interfering side reactions. We have successfully tested new ceramic kinetic reactors in two model systems of propane dehydrogenation and reactor coil material. The presented reactor setup allows long-term measurements with industrially relevant material samples under controlled conditions. In both model reactions it was possible to perform studies on regeneration methods by oxidation and to study the effects on the material using different in-situ and ex-situ techniques including 31(P) MAS NMR measurements.

Present knowledge about the fate of persistent and mobile (PM) substances in drinking water treatment is limited. Hence, this study assesses the potential of fixed-bed granular activated carbon (GAC) filters to fill the treatment gap for PM substances and the elimination predictability from lab-scale experiments. Two parallel pilot filters (GAC bed height 2 m, diameter 15 cm) with different GAC were operated for 1.5 years (ca. 47,000 BV throughput) alongside rapid small-scale column tests (RSSCT) designed based on the proportional diffusivity (PD) and the constant diffusivity (CD) approaches. Background dissolved organic matter (DOM) and a set of 17 target substances were investigated, among them 2-acrylamido-2-methylpropane sulfonate (AAMPS), adamantan-1-amine (ATA), melamine (MEL) and trifluoromethanesulfonic acid (TFMSA). Nine substances were predominantly present in the drinking water used as pilot filter influent (frequencies of detection above 80 %, median concentrations 0.003-1.868 μg/L) and their breakthrough behaviors could be observed: TFMSA was not retained at all, four substances including AAMPS and ATA reached complete breakthrough below 20,000 BV, three compounds were partially retained until the end of operation and oxypurinol was retained completely. The comparable PM candidate and DOM removal performances of both GAC aligns with their very similar surface characteristics and elemental compositions. The agreement of results between RSSCT with the pilot-scale filters were substance specific and no superior RSSCT design could be identified. However, CD-RSSCT provide a conservative removal prediction for most studied compounds. MEL adsorption was significantly underestimated by both RSSCT designs. Using the criterion of a carbon usage rate (with respect to 50 % breakthrough) below 25 mgGAC/Lwater for an economic retention by fixed-bed GAC filters, five (out of nine) substances met the requirement.

Persistent and mobile (PM) substances among the organic micropollutants have gained increasing interest since their inherent properties enable them to enrich in water cycles. This study set out to investigate the potential of adsorption onto activated carbon as a drinking water treatment option for 19 PM candidates in batch experi-ments in a drinking water matrix using a microporous and a mesoporous activated carbon. Overall, adsorption of PM candidates proved to be very variable and the extent of removal could not be directly related to molecular properties. At an activated carbon dose of 10 mg/L and 48 h contact time, five (out of 19) substances were readily removed (>= 80%), among them N-(3-(dimethylamino)-propyl)methacrylamide, which was investigated for the first time. For five other substances, no or negligible removal (< 20%) was observed, including 2-methyl-2-propene-1-sulfonic acid and 4-hydroxy-1-(2-hydroxyethyl)-2,2,6,6,-tetramethylpiperidine. For the former, current state of the art adsorption processes may pose a sufficient barrier. Additionally, substance specific sur-rogate correlations between removals and UVA254 abatements were established to provide a cheap and fast estimate for PM candidate elimination. Adsorption onto activated carbon could contribute significantly to PM substance elimination as part of multi barrier approaches, but assessments for individual substances still require clarification, as demonstrated for the investigated PM candidates.