Soluble Pollutants Research Articles

Optimal Control for Transmission of Water Pollutants

Pollutants are formed when oil, gas, chemical plants, etc. discharge their harmful waste materials into stream or other water bodies. In this paper, a mathematical model for water pollutants which are soluble and insoluble has been formulated as a system of non-linear ordinary differential equations. Control is applied on insoluble water pollutants to process them into soluble water pollutants. Numerical simulation has been carried out which suggest that soluble water pollutants are increasing as compared to insoluble water pollutants.

Effects of water soluble perfluorinated pollutants on phospholipids in model soil decomposer membranes

Water soluble perfluorinated compounds (PFCs) as perfluorooctanesulfonate (PFOS), perfluorooctanoate (PFOA) and their shorter chain homologues are persistent organic pollutants widely distributed in the environment. PFCs accumulate in soils and sediments and because of their toxicity endanger the decomposer organisms. PFCs are toxic to a wide spectrum of soil bacteria and their biocide activity was related with their membrane activity; however, the exact mechanism of PFCs – bacterial membrane interactions is unknown. Therefore, to shed light on these questions we applied phospholipid Langmuir monolayers as simplified models of bacterial membranes and studied their interactions with selected environmentally relevant PFCs. The mechanical properties of the monolayers were characterized by surface pressure-mean molecular area isotherms and the analysis of compression modulus. The effects of PFC on the texture of the model membranes were studied with Brewster angle microscopy, whereas their influence on molecular packing in the 2D crystal lattice was searched by the Grazing Incidence X-ray diffraction technique. The effects of PFCs on the phospholipid polar heargroup conformation were studied by PM-IRRAS spectroscopy, whereas the effectivenes of the incorporation of PFCs into the model membrane was monitored in penetration tests. It turned out that the membranes rich in phosphatidylethanolamine typical to Gram negative bacteria are much PFCs susceptible than the cardiolipin rich membranes imitating Gram positive species. Moreover, the studies indicated that the switch from eight‑carbon atom perfluorinated chains to shorter chain homologues is not necessarily environmentally benign as perfluorobutane sulfonate caused also significant structural changes in the model membranes.

Fabrication of superhydrophobic Cu-BiOBr surface for oil/water separation and water soluble pollutants degradation

Materials with superhydrophobicity have been successful in removing and recovering oily pollutants in water, however, it cannot get rid of water soluble pollutants. In this paper, we prepared a superhydrophobic Cu-BiOBr surface which combined the superhydrophobicity with the photodegradation property to realize the oil/water separation and the removal of water-soluble pollutants. The result shows that the surface of the material has macroporous (620 nm) and mesoporous (3.2 nm) structure. The degradation efficiency for Rhodamine B (Rh B) does not change after 5 times of repeated use, which indicates the good degradation stability of the material. In addition, the surface remains superhydrophobic and high flux for up to 11 cycles. The preparation process is simple and economical with no complicated and expensive equipment but only filtration and spraying used. A 13 cm × 13 cm superhydrophobic Cu-BiOBr mesh was also prepared to verify the feasibility of large scale fabrication.

Influence of deep water formation by open-sea convection on the transport of low hydrophobicity organic pollutants in the NW Mediterranean Sea

The significance of the offshore vertical convection currents in the transport and sinking of water-soluble organic pollutants into marine deep basins has been evaluated. For this purpose, sediment cores were collected in the Gulf of Lion (GoL) at sites between 26 and 2330 m water depth. The top core layers were analyzed for aromatic and aliphatic hydrocarbons and organochlorine compounds. Organic compounds with logKAW (air water partition coefficient) between −2 and −4, e.g. lindane, PCB 28, PCB 52, phenanthrene, methylphenanthrenes, dimethylphenanthrenes, C14–C23n-alkanes, are found in higher concentrations or exhibit relative concentration increases in the sediments deposited in the continental rise as consequence of the open-sea convection processes associated with the formation of Western Mediterranean Deep Water (WMDW). In contrast, the organic pollutants with intermediate air-water distribution coefficients, logKAW between −2 and 0, and high octanol water distribution coefficients (logKow > 6), e.g. highly chlorinated PCBs, DDTs, DDEs, DDDs, C25–C35n-alkanes, and polycyclic aromatic hydrocarbons with molecular weight higher than 200, occur in association to sediment particles, which are mainly transported by the Northern current along the continental shelf forming the mud belt. The Rhône prodelta is therefore the area of the GoL showing the highest concentrations of this group of organic compounds, which are preferentially associated with water particles. Overall, the results show that vertical open-sea convection processes related with offshore formation of WMDW may have an important role in the transport and accumulation of water soluble pollutants to deep marine environments of the GoL (>2000 m water depth).

Electrocoagulation (EC) for the Removal of Silica from Mining ARD Water Treatment

During the nanofiltration (NF) and reverse osmosis (RO) process, ions in the reject stream becomes increasingly concentrated. NF/RO concentrates from the treatment of mining acid rock drainage (ARD) water contain high levels various impurities—depending on the geochemistry of the waste rock and the treatment processes applied. Presence of cross-linked fine colloidal particles, especially silica, at certain levels in NF/RO concentrate streams can cause membrane fouling creating significant operational and water management challenges. Electrocoagulation (EC) is a mature technology for many types of industrial waste water treatments. The technology can remove metal ions, colloidal suspensions, fine particles, and soluble inorganic pollutants from aqueous solution by introducing highly charged polymeric metal hydroxide species. In this paper, EC is explored as a treatment option for concentrated ARD water with focus in silica removal. Fe metal plates were employed as sacrificial electrodes. The experiments systematically investigate the influence of pH, dissolved oxygen (DO), current density (CD), and duration on the formation of green rusts (GRs) and silica removal. Batch tests have proved the concept that EC is a viable approach for silica removal from 80% RO reject water. Silica can be reduced from ~14 ppm down to ~3.0 ppm under 25mA/cm2 current density for 60 minute or 12.5 mA/cm2 for 120mins. Such level of silica removal can alleviate membrane fouling during subsequent NF/RO treatment. The DO level in solution has an important influence on pH and water chemistry, governs ferrous or ferric or ferrous/ferric mixed GR generation, and impacts the removal of silica in RO rejects from ARD water. EC with ferrous green rust formation under lowest DO level is best for silica removal.

Geostatistical Analysis of the Permeability Coefficient in Different Soil Textures

Summary Estimating soil hydraulic properties are so important for hydrological modeling, designing irrigation-drainage systems and soil transmission of soluble salts and pollutants, although measurements of such parameters have been found costly and time-consuming. Owing to a high spatial variability of soil hydraulic characteristics, a large number of soil samples are required for proper analysis. Nowadays, geostatistical methods are used to estimate soil parameters on the basis of limited data. The purpose of this research is to investigate the spatial variability of the permeability coefficient in different soil textures (26 soil samples) found in the Kurdistan region of Iraq. The parameter values obtained indicated a normal trend in particle size distribution, whereas the values of permeability coefficient showed aberrant distribution patterns. Geostatistical analysis results indicated the best fitted theoretical model was Gaussian model and the proportion of sill/(sill + nugget) was 0.17 indicated strong spatial dependency of soil permeability. Furthermore, the optimal distance for estimating the soil permeability coefficient was 109,119 meters. A comparison of the kriging and IDW interpolation methods showed that both methods can estimate soil permeability with high accuracy and less error. The prediction maps of the applied methods indicated that high soil permeability rates were recorded in the south-east of the Kurdistan region of Iraq compared to low soil permeability rates recorded in the remainder of this region. It is recommended other interpolation methods such as co-kriging and indicator or simple kriging methods could be used to simulate data in large scale areas as well.

Chitosan-macroalgae biocomposites as potential adsorbents of water-soluble hydrocarbons: Organic matter and ionic strength effects

Abstract Nowadays the recovery of low-molecular soluble aromatic hydrocarbons (HCs) released into natural bodies of water continues to be a challenging task. These contaminants bring sever consequences to the environment and to the human health. Biosorption on macroalgae (Ma) biomass seem to be a potential alternative due to low costs and high availability, but the low strength and density are important drawbacks to handle, start up and operate continuous biosorption units. In this study, chitosan (Ch) and pectin (Pe) were employed as precursors to synthesize a new Ma−Ch−Pe composite with regard to enhance the stability and applicability of macroalgae biomass towards the removal of soluble HCs pollutants. The biocomposite synthesis was based on a factorial design and a posterior response surface methodology. The optimized biocomposite (75.4%, 19.8 and 4.8% for macroalgae biomass, chitosan and pectin, respectively), was characterized and evaluated under different ionic strengths, pH values and organic load to determine their potential as biosorbents and to elucidate the adsorption mechanisms involved. Removal capacities were 58.68, 16.64 and 6.13 mg g−1 for benzene, toluene and naphthalene, respectively. The adsorption capacity was slightly influenced by the pH (3–9), and diminished with ionic strength values up to I > 0.6 M. The presence of dissolved organic matter (DOM) enhanced the removal of HCs by providing hydrophobic sites to the biosorbents. Moreover, the biosorption data was well-described by Sips adsorption isotherm, and the pseudo-second order equation represented the best fitting model for the biosorption kinetics. The biosorption mechanisms included hydrophobic effect by the algae fraction and London forces between the HC and the diverse of functional groups present offered by the precursors.

Rapid mass production of novel 3D Cu@CuI core‐shell mesh as highly flexible and efficient photocatalyst

AbstractWe report a relatively simple and economical approach for mass production of Cu@CuI mesh. This novel core‐shell structure is CuI‐coated Cu mesh, fabricated by one‐step in situ iodination of commercial copper mesh at an ambient temperature. Such a Cu@CuI mesh is low‐cost and can be successfully used for the degradation of soluble organic pollutants in water under UV light. The novel 3D Cu@CuI core‐shell structure allows for high electron/hole separation and thus leads to high catalytic efficiency. Rhodamine B (RhB) is fully degraded in even just 6 minutes using a Cu@CuI mesh as the photocatalyst. Unlike the currently reported photocatalysts mostly in the form of powders, nanoparticles, and/or nanowires, the 3D Cu@CuI mesh is freestanding and flexible, and therefore is easily separated from water after photocatalysis without causing secondary pollution. This is a significant advance toward tackling the expansive separation issue of the conventional catalysts, because the ultra‐simple separation process of 3D Cu@CuI mesh can facilitate its industry application. With a fantastic combination of low cost, facile and green fabrication, high catalytic efficiency and easy separation 3D architecture, the Cu@CuI mesh may serve as a promising candidate for water purification.

Industrial waste as a source of surface and groundwater pollution for more than half a century in a sector of the Río de la Plata coastal plain (Argentina)

Environmental liabilities have become one of the most important problems of the last years, especially those of contaminated sites located in urban areas which have been abandoned by pollution intensive industries. Such sites may contain hazardous materials that pose risks to human health and the environment. Industrial waste from the ancient sulfuric acid industry is scattered in a local area at the petrochemical pole in a sector of the Río de la Plata coastal plain. The aim of this work is to define the geochemical processes that determine the alteration of waste in the old sulfuric acid industry (OSAI) area and to study the migration of soluble pollutants to groundwater. A survey of soil and waste deposit was carried out and samples were examined by X-ray diffraction, under a scanning electron microscope and a polarizing microscope. Surface water and groundwater samples, both to the unconfined and semi-confined aquifers, were collected to determine electrical conductivity, pH and major elements. The results show the presence of minerals composed of sulfur associated with jarosite and iron oxides on superficial sediments. The detailed study of soil sediments together with that of the water physicochemical characteristics make it possible to understand the geochemical processes developed in soil that cause the high concentrations of sulfates in groundwater. Furthermore, high SO4−2 concentration registered in the semi-confined aquifer due to its infiltration from the unconfined aquifer shows that the industrial pollution has an important impact at local level. These results may contribute to the understanding of chemical processes and pollutants distribution in highly industrialized coastal plain areas.

Sonocatalytic performance of magnetically separable CuS/CoFe2O4 nanohybrid for efficient degradation of organic dyes

The sonocatalytic activity of the magnetic CuS/CoFe2O4 (CuS/CFO) nanohybrid was studied through the H2O2-assisted system for degradation of water soluble organic pollutants such as methylene blue (MB), rhodamine B (RhB) and methyl orange (MO). The CuS/CFO nanohybrid was fabricated at 200 °C by hydrothermal method. X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM) equipped with energy dispersive X-ray microanalysis (EDX), Fourier-transform infrared spectroscopy (FT-IR), UV–Vis spectroscopy, magnetic measurements, and Brunauere-Emmette-Teller (BET) were employed for the characterizing the structure and morphology of the so-synthesized nanohybrid. Compared with sonolysis/H2O2, the higher degradation of MB (25 mg/L) was achieved via sonocatalytic process. The degradation efficiency of sonolysis/H2O2, sonocatalysis using CuS/H2O2, CFO/H2O2 and CuS/CFO/H2O2 systems was 6%, 62%, 23% and 100% within reaction time of 30 min for MB, respectively. The integration of H2O2 and catalyst dosage intensified the sonocatalytic degradation of MB. On the other hand, adding a hydroxyl radical (OH) scavenger (tert-butyl alcohol) and a hole scavenger (disodium ethylenediaminetetraacetate) decreased the degradation efficiency from 100% to 35% and 72% within 30 min, indicating the OH radicals as prominent oxidizing agent of this process. Furthermore, the magnetic property of the sample helped for easier separation of the nanohybrid, made it recyclable with a negligible decline in the performance even after four consecutive runs.

Are electrochemical fences effective in the retention of pollution?

Abstract In this work, a three-month test is used to evaluate the role of electrokinetic fences in the prevention of the diffusion of herbicide in case of accidental spills of large amounts of highly concentrated products in clay soil. To do this, a mock-up (0.95 × 2.00 × 0.50 m 3 ) is used and an electrokinetic fence is placed far away from the hydraulic plume in order to mitigate the effect of the diffuse pollution caused by the spill of an important amount of 2,4-dichlorofenoxiacetic acid (2,4-D) and oxyfluorfen. The results confirm that diffusion of pollutants is important and that the presence of an electrokinetic fence can contain micellar pollutants and help to minimize the trespassing of soluble pollutants, although they cannot fully prevent this trespass. The results obtained in this work are compared to those obtained in previous works, in which fence technology with surrounding electrode placement was evaluated and important differences were pointed out; this has generated valuable data for the design of this technology.

Humic like substances for the treatment of scarcely soluble pollutants by mild photo-Fenton process

Humic-like substances (HLS) extracted from urban wastes have been tested as auxiliaries for the photo-Fenton removal of thiabendazole (TBZ) under simulated sunlight. Experimental design methodology based on Doehlert matrices was employed to check the effects of hydrogen peroxide concentration, HLS amount as well as TBZ loading; this last parameter was studied in the range 25–100 mg/L, to include values below and above the limit of solubility at pH = 5. Very satisfactory results were reached when TBZ was above solubility if HLS and H2O2 amounts were high. This could be attributed to an interaction of HLS-TBZ that enhances the solubility of the pollutant. Additional evidence supporting the latter interaction was obtained by fluorescence measurements (excitation emission matrices) and parallel factor analysis (PARAFAC).

Chemically Assisted Primary Sedimentation as a tool to improve energy balance of a large wastewater treatment plant

Chemicals addition at the mechanical part of wastewater treatment plant can improve overall treatment efficiency and help in solving some plant’s operational problems. Application of such process in the primary clarifiers, named as Chemically Assisted Primary Sedimentation, can also be a huge step towards energy balance improvement for the whole plant. Use of relatively cheap coagulants, such as ferric or alum salts can be an easy way to increase treatment efficiency significantly, as coagulation and flocculation intensifies followed by chemical precipitation. Additional removal of soluble pollutants and suspended solids increases their load in the primary sludge, avoiding their potential removal in the biological part of the plant. Additional organic matter in the primary sludge allows to produce more gas in the anaerobic digestion process and thus increase energy production by the CHP units. Efficiency of different coagulation agents (PIX 109 and PAX XL3) supported by polymer addition was investigated using real municipal wastewater collected from a large Polish wastewater treatment plant (over 500 000 p.e.) in a series of lab-scale tests. Proper selection of coagulant and potential polymer dosage has a serious impact on the overall costs of this additional treatment and energy balance. Based on obtained results, economic analysis was performed for the same plant to evaluate potential gains and losses of implementing such practice.

Bifunctional MoS2 coated melamine-formaldehyde sponges for efficient oil–water separation and water-soluble dye removal

Removal of pollutants from water is an important global challenge for energy conservation and environmental protection. Advanced macro-porous sorbent materials with three-dimensional wettability surfaces have been considered traditional candidates for wastewater treatment. Although the real water environment always co-exists with two pollution sources, the major functions of existing macro-porous materials are limited to either water-insoluble organics separation or water-soluble dyes removal. Bifunctional macro-porous materials for simultaneous oil–water separation and soluble elements removal are currently lacking. Here we report the novel MoS2-coated melamine-formaldehyde (MF@MoS2) sponges with different wettabilities, for example, superhydrophobicity and superhydrophilicity, exhibiting both high selectivity and excellent absorption capacities for a wide range of oils/organic solvents with different densities and water-soluble dyes. The functional MF@MoS2 sponges perform high absorption capacity for different organic solvents up to 66 and 157 times of its own weight respectively, while showing high discoloration efficiency of 98% methyl orange within 10min. For the first time, we report these functional macro-porous materials used for simultaneous cleaning of oil and soluble pollutants in water, which extended the potential of MoS2 for environmental application. Furthermore, a continuous and simultaneous removal of insoluble oils and soluble dyes in situ from water was achieved by simply applying external pumping on the functional macro-porous MF@MoS2 sponges.

Simultaneous methane abatement and PHB production by Methylocystis hirsuta in a novel gas-recycling bubble column bioreactor

The limited gas–liquid mass transfer represents the main challenge in the operation of cost-effective bioreactors devoted to the treatment of poorly soluble gas pollutants such as methane (CH4). This study evaluates the influence of internal gas-recycling strategies on the enhancement of CH4 abatement in a bubble column bioreactor inoculated with the methanotroph Methylocystis hirsuta. Maximum CH4 removal efficiencies of 72.9 ± 0.5% (corresponding to elimination capacities of 35.2 ± 0.4 g m−3 h−1) were recorded under process operation at an empty bed residence time of 30 min and 0.50 m3gas m−3reactor min−1 of internal gas-recycling rate. The accumulation of poly-3-hydroxybutyrate (PHB) in M. hirsuta was evaluated batchwise under limitations of potassium, manganese, nitrogen, and nitrogen with excess of iron. Nitrogen starvation resulted in the highest PHB content (28 ± 1%). Likewise, the implementation of sequential N starvation cycles in a continuous bubble column reactor operated at a gas residence time of 30 min and an internal gas-recycling rate of 0.50 m3gas m−3reactor min−1 supported a PHB content of up to 34.6 ± 2.5%, with a volumetric PHB productivity of 1.4 ± 0.4 kg m−3 d−1 and elimination capacities of 16.2 ± 9.5 g m−3 h−1.

Removal of Organic Pollutants from Water Using Superwetting Materials.

The frequent occurrence of water pollution accidents and the leakage of organic pollutants have caused severe environmental and ecological crisis. It is thus highly imperative to find efficient materials to solve the problem. Inspired by the lotus leaf, superwetting materials are receiving increasing attention in the field of removal of organic pollutants from water. Various superwetting materials have been successfully generated and integrated into devices for removal of organic pollutants from water. On the basis of our previous work in the field, we summarized in this account the progress of removal of (1) floating and underwater insoluble, (2) emulsified insoluble, and (3) both insoluble and soluble organic pollutants from water using superwetting materials including superhydrophobic & superoleophilic materials, superhydrophilic & underwater superoleophobic materials, and materials with controllable wettability. The superwetting materials are in the forms of 2D porous materials, 3D porous materials and particles, etc. Finally, the current state and future challenges in this field are discussed. We hope this account could shed light on the design of novel superwetting materials for efficient removal of organic pollutants from water.

Graphene Oxide/Chitosan Aerogel Microspheres with Honeycomb-Cobweb and Radially Oriented Microchannel Structures for Broad-Spectrum and Rapid Adsorption of Water Contaminants.

Multifunctional graphene oxide (GO)/chitosan (CS) aerogel microspheres (GCAMs) with honeycomb-cobweb and radially oriented microchannel structures are prepared by combining electrospraying with freeze-casting to optimize adsorption performances of heavy metal ions and soluble organic pollutants. The GCAMs exhibit superior adsorption capacities of heavy metal ions of Pb(II), Cu(II), and Cr(VI), cationic dyes of methylene blue (MB) and Rhodamine B, anionic dyes of methyl orange and Eosin Y, and phenol. It takes only 5 min to reach 82 and 89% of equilibrium adsorption capacities for Cr(VI) (292.8 mg g-1) and MB (584.6 mg g-1), respectively, much shorter than the adsorption equilibrium time (75 h) of a GO/CS monolith. More importantly, the GCAMs maintain excellent adsorption capacity for six cycles of adsorption-desorption. The broad-spectrum, rapid, and reusable adsorption performance makes the GCAMs promising for highly efficient water treatments.

A modified 5000 h test procedure for silicone rubber insulator based on contamination and hydrophobicity change simulation

A large number of silicone rubber (SR) insulators have been used in inland areas. Long-term performance evaluation, pre-ranking and selection of these insulators are highly significant. IEC and other institutes have proposed several 5000 h tests with multiple stresses to evaluate long-term performances of composite insulators. However, these procedures have their own characteristics and limitations. None of the existing tests could provide a satisfactory simulation of the condition with severe contamination and high non-soluble deposit density (NSDD) in inland areas as well as the hydrophobicity change process of SR insulators. Based on modifications of the IEC test procedure, a novel 5000 h test procedure is proposed. There are two main modifications. The first one aims to replace the salt fog with a mixed contamination fog including both soluble and non-soluble pollutants. The second one aims to provide sufficient time for SR to recover and to transfer its hydrophobicity. A set of test apparatus based on this novel 5000h test procedure was designed and constructed. Two tests were conducted on 16 SR insulators with different material compositions and shed designs, including an AC and a negative DC test. Contamination accumulation on the surfaces of the specimens during both tests were measured. The NSDD and equivalent salt deposit density (ESDD) were close to those measured in the field in contaminated inland areas. Hydrophobicity reduction and recovery were well reproduced. Discharge activities were observed and leakage current was measured, which were consistent with the hydrophobicity statuses of the specimen. Tracking and erosion were found for some specimens, and the damage pattern was the same with that found in the field. The poor material properties and inappropriate shed designs could be identified successfully through the test. It was concluded that the modified 5000 h procedure could provide a satisfactory simulation of the desired contamination condition and hydrophobicity change process, and the insulators with different design defects are successfully screened out.

Study on the flashover performance of various types of insulators polluted by nitrates

Pollution materials affect insulator flashover performance, and there is long-term significance in researching it. In this paper, common kinds of nitrates were used as the soluble pollution, and the ac flashover performance of four types of insulators under different nitrates were investigated. Basing on a large amount of primary data, the calculation of flashover gradient in specific to different pollution materials was discussed, and the effects of nitrates on it were analyzed. Research results indicate that, flashover gradient of insulator under nitrates is commonly higher than that under NaCl; among the nitrates, KNO3 corresponds to lower insulator flashover gradient while Ca(NO3)2 corresponds to a higher one; the exponent b, which characterizing the influence of ESDD on flashover gradient, is lower under nitrites than that under NaCl; for the four insulator samples polluted by nitrates, the flashover gradient of the porcelain type can be expressed by A×ESDD−0.21×NSDD−0.16, the flashover gradient EL of the glass type can be expressed by A×ESDD−0.22×NSDD−0.14, while that of the composite samples can be expressed by A×ESDD−0.19×NSDD−0.13. Research data may provide references for the better prediction of flashover voltage as well as for the better design of external insulation.

Monitoring the accumulated water soluble airborne compounds deposited on surfaces of showcases and walls in museums, archives and historical buildings

BackgroundCultural heritage objects are subject to the deposition of a multitude of airborne pollutants even when kept inside museums, archives, historical buildings or showcases. Some of the pollutants are quickly deposited onto any available surface, including the interior walls and CH objects themselves. This might make the compounds seem absent from analyses of indoor air samples.Context and purpose of the studyA new method of detecting water soluble pollutants without taking samples from the interior walls or from the CH objects themselves has been developed. The method involves sampling the pollutants accumulated on a surface near the CH object, e.g. a nearby wall or an interior glass surface of a showcase. The samples were obtained by gently flushing the surface with deionised water to collect the ions readily removed from the surface. The method was tested on a variety of surfaces.Results and main findingsThe flushed water were analysed with IC (Ion Chromatography) and ICP-MS (Inductively Coupled Plasma Mass Spectrometry) and included ions of Al, As, Ba, Ca, CH3COOH, Cl, Co, (COOH)2, Cr, Cu, F, Fe, K, Mg, Mn, Na, NH4, Ni, Pb, S, Sb, Si, Sn, Sr, Ti and Zn, and the ions NO3−, PO43−, and SO42−. The resulting concentrations were converted to µEq, providing the ionic balance and the relative amounts of the ions and elements present. Ionic balance was observed on smooth and inert surfaces, but in some cases the chemistry of the wall contributed to the flush water. Solid samples of some of the surfaces have been analysed by XRF to clarify these more complex situations.ConclusionsClear results appear from smooth or well defined surfaces, whereas more complex situations arise when the underlying surface itself contributes to the flush water. The method is working very well and is easy and cheap to implement by curators and conservators, who can the send the flush water to specialized laboratories.Brief summaryA new methodology capable of monitoring the accumulated airborne deposits on surfaces in showcases and historic buildings is presented and tested. The method is cheap and is easy to implement by curators and conservators and allows the assessment of threats to the CH objects which are not always observed by analyses of the indoor air. Graphical abstractA novel method is presented detecting water soluble airborne pollutants without taking samples of the cultural heritage objects themselves. Left: schematic diagram depicting the sampling method. a Handheld squeeze bottle; b funnel made from aluminum foil to collect the flushed water; c plastic bottle collecting the flushed water; right: applying the flush water on the interior glass wall of a show case (Photo: Kaare Lund Rasmussen)