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Discharge of acid mine drainage (AMD) from abandoned coal mines of the YuDong catchment in Kaili City, Guizhou Province, China, has severely damaged local ecological environments. In this study, a laboratory-scale dispersed alkaline substrate (DAS) was studied for the treatment of simulated AMD. The experimental conditions and reaction mechanisms were preliminarily explored. The treatment effect and variation law of vertical effluent water quality of the experimental conditions were thoroughly analysed. The results indicated that small-sized limestone (diameter 5–7 mm) having a 20:1 mixture ratio with shavings and minimum HRT of 20 hours result in increasing effluent pH from 3.5 to 6.6, achieving 66.2% and 99.1% removal of Fe and Al, respectively. There were obvious differences in each reaction layer for the removal of various pollutants from AMD along the depth by DAS, the main reaction zone was first 20–30 cm of the reaction column. The removal process of metal ions and sulfate was accompanied by bio-mineralization reaction. This test provided a valuable support for the local practical engineering applications, enriched the AMD processing technology experimental cases, and provided reference for the treatment technology of similar polluted areas. HIGHLIGHTS A dispersed alkaline substrate was designed to treat the acid mine drainage from abandoned coal mines of YuDong valley, which provides a reference for the further design of site device and other similar contaminated areas.; Combining the physical and chemical parameters of the effluent, and mineralogical characterization of the filler along with the microbial diversity of the system, the mechanism of DAS treatment of AMD was analyzed.; Under this experiment conditions, DAS can raise the effluent pH to 6.6, and the average removal rate of Fe and Al was 66.2% and 99.1%, respectively. Daily decrease rate of Fe was 16∼18 g/m2/d.

The mineralogical and geochemical characterization of sediments of the Reconquista River allows analyzing the geochemical partition of trace elements in one of the most polluted water courses of Argentina. The low dissolved oxygen and high ammonia contents, together with the high chemical oxygen demand, attest to the poor water quality. Ammonia, Cd and Cu content in surficial water exceeds the maximum guidelines for freshwater in Argentina. The recent sediments of the uppermost bed are enriched in organic matter (OM), sulfur, Zn, Cu and Pb. The enrichment factor is moderate, and the geoaccumulation index (Igeo) for Cu and Pb indicates uncontaminated to moderately contaminated sediments. The positive and significant correlation between As, Cr, Pb and Zn with the iron content suggests that their retention is controlled by the amount of iron oxy (hydr)oxides in the sediments, probably combined with the silt + clay abundance. In comparison with its tributary, the Las Catonas Stream, the Reconquista River, has less OM and trace elements in the sediments and more dissolved trace elements in the interstitial water. We interpret that OM is the main sorbent of the trace element. In the absence of OM, the iron oxy (hydr)oxides and the silt + clay fraction are a less efficient substitute. Consequently, the interstitial waters of the Reconquista River are enriched in these elements. Therefore, minor changes in the environmental conditions may generate significant release of hazardous trace elements from the sediments to the interstitial water and, in turn, to the surficial water of the river. As most of the big cities and the agricultural activities of Argentina are developed on the loessic substrate, the understanding of its interaction with polluted waters is crucial.

The choice of suitable substrates has received special attention in aquaculture and fishkeeping ventures. The aim of this study was to evaluate the influence of different substrates on water quality and the development of lambari fish (Astyanax bimaculatus) and freshwater shrimp (Macrobrachium potiuna). Two experiments were performed sequentially, one with fish and the other with shrimp. In both experiments, three different substrates were evaluated (shell gravel, river gravel, and dolomite), and the control was without any substrate. The water parameters evaluated were as follows: dissolved oxygen, saturation, oxide-reduction potential, temperature, pH, alkalinity, conductivity, ammonia, nitrite, nitrate, and phosphorus. It was observed that both dolomite and shell gravel interfered with the parameters that are related to the acid-base balance of the water and the availability of calcium and magnesium. The productive performance of lambari fish was not affected considering the different substrates evaluated; however, the productive performance of freshwater shrimp was lower in the absence of substrates in relation to the other treatments.

The use of recycled glass as a substrate for constructed wetlands was assessed through two studies. The first study examined the dissipation of atenolol, carbamazepine, and sulfamethoxazole in mesocosm-modeled wetlands using glass or limestone gravel as substrates, with or without cattails (Typha spp.). Following pseudo-first-order kinetics, atenolol dissipated the fastest from the water surface of the mesocosms (t1/2~1 day), followed by sulfamethoxazole (t1/2~14 days), and carbamazepine (t1/2~48 days), with no significant differences across treatments. Increased half-lives were observed at greater depth, likely due to light screening. A Monte Carlo sensitivity analysis diagnosed sunlight absorption rates and second-order hydroxyl-mediated indirect photolysis rates to be the main sources of uncertainty in our dissipation rate estimates, compared to our observed rates. The second study examined in situ pharmaceutical removal in tertiary pilot-scale subsurface filters made of crushed recycled glass or sand in a wastewater treatment facility in Manitoba, Canada. Glass and sand showed no significant differences for pharmaceutical removals; atenolol and metoprolol were removed below limits of detection, while carbamazepine and sulfamethoxazole persisted over a retention time of 24 h. Overall, recycled glass performed similarly to traditional substrates for wetland-based wastewater treatment.

Aside from ornamental uses of killifishes, there is growing interest in using killies for a multiplicity of purposes including baitfish and mosquito biocontrol. This experiment explored the spawning habits and embryonic development of the banded lampeye, Aplocheilichthys spilauchen in ex situ freshwater (0.04 ‰) and brackish water (5.01 ‰) to ascertain the captive breeding prospects for mosquito control in areas where they occur. Significantly higher number of eggs were laid in the brackish water than the freshwater (ꭓ2 = 1613.0, P < 0.05), and black mop was the most preferred spawning substrate, followed by green, blue and white mops. Microscopic monitoring of embryos revealed that cleavage occurred within the first 30 min after fertilisation, organogenesis commenced in averagely the 25th hour, and hatching in approximately 230 h. Although freshwater eggs were relatively bigger than brackish water eggs and certain embryonic developmental stages occurred faster in the freshwater than brackish water, these differences were overall not significant and had no effects on the development and hatching. The observed outcome that A. spilauchen can be optimally propagated with black mops in brackish water offers a significant step in its use for the mosquito biocontrol programme, as well as other potential uses not yet explored.

Ostrea edulis is one of the most common types of meat oysters and is commonly consumed by people in Kuala Gigieng, but until now there is not much scientific information about this species. The purpose of this study was to describe the ecomorphology of Ostrea edulis in Kuala Gigieng waters. This research was conducted from August to September 2013 in Kuala Gigieng Waters, Aceh Besar District. The method used in this research is purposive sampling. Identification of samples based on shell morphological characteristics including the exterior and interior of the shell using a magnifier lamp. The results showed that Ostrea edulis found in Kuala Gigieng waters had round, rough, hard, thick and uneven shells. The two valves are also not the same size, where the left valve is more concave than the right valve which tends to be flat. This is a form of the adaptation pattern of Ostrea edulis in Kuala Gigieng which tends to have a medium sand and clay sand substrate with a fairly high predation from both natural and human predation.

SEM-EDS analysis of cobalt-rich Fe–Mn crusts (CRFMC) and their substrate rocks from the Gummy Bear seamount in the northwestern Pacific Ocean and the Magellan seamounts (Ilyicheva and Vulcanologist guyots) in the subequatorial Pacific Ocean revealed the presence of accessory (0.6–40 μm) two- and three-component minerals of the Ag–Au–Cu system, which is indicative of a wider distribution of authigenic gold mineralization than one would expect for such deposits. A concept for the biogeochemical genesis of these natural alloys was proposed, including the processes of biosorption, bioaccumulation, and biotransformation of metal ions by microbial cells to their metallic nano- and microforms.

Subirrigation systems are widely used in commercial greenhouses for efficient and high-quality production of potted plants. However, proper criteria of the water level and retention time need to be quantified for more efficient irrigation. This study analyzed the water absorption and vertical water distribution in a horticultural substrate in 10-cm pots under various subirrigation water levels and retention times. To analyze the water absorption dynamics, we continuously measured changes in the actual substrate volumetric water content using capacitance soil moisture sensors. The vertical distribution of water in the pot was measured using a thermal imaging camera, with a small temperature difference indicating more water absorption. As expected, the volumetric water content in the pots increased as the subirrigation water level and retention time increased; however, significantly less water was absorbed near the top surface of the substrate, and the variation of the vertical water distribution increased at lower subirrigation water levels or shorter retention times. This suggests that young plants with smaller root systems would require a higher water level and retention time for subirrigation if their roots are distributed near the top of the pot. This study provides a better understanding of water absorption and its vertical distribution across a horticultural substrate when using a subirrigation system and supports decision making for the suitable management of subirrigation conditions according to the type of plant species or crop growth stage.

Lake Maninjau is one of the tectovulcanic type lakes in West Sumatra Province which is used as a food source in the presence of fauna groups such as mollusks. The main purpose of this study is to determine the distribution of mollusks concerning the substrate in Lake Maninjau. This research was conducted three times from March-September 2015 at seven points of the river estuary around Lake Maninjau. The result of the study shows that Corbicula moltkiana was mostly found at Pandan station, while Melanoides tuberculata and Anodonta woodiana were mostly found at Muko-Muko station. The distribution pattern of Corbicula moltkiana and Melanoides tuberculata shows a tendency to live in groups. The waters of the estuary around Lake Maninjau are dominated by sand with TN and TP concentrations ranged from 0.093 - 0.610 mg kg-1 and 0.427 - 2.137 mg kg-1, respectively.

The effects of three environmental factors, salinity, carbonate alkalinity, and pH, on the survival, feeding, and respiratory metabolism of Eogammarus possjeticus (Amphipoda: Gammaridae) were investigated experimentally. The results show that E. possjeticus could tolerate a broad salinity range. The 24-h lowest median lethal salinity was 2.70, and the highest was 47.33. The 24-h median lethal alkalinity and pH were 23.05 mmol/L and 9.91, respectively; both values decreased gradually with time. Different values of salinity, carbonate alkalinity, and pH resulted in significant differences in the cumulative mortality (P

Summer bleaching of corals has been prevalent in the coastal waters of India in recent years before the onset of monsoon. Repeated bleaching of shallow water corals has changed the benthic dynamics of reef ecosystems. In the present study two locations, Wandoor and Burmanullah in South Andaman, were identified where such changes have occurred. After 3 years of study, the shift from coral domination to macroalgae and sponge is evident. In Wandoor, fleshy macroalgae (28.80%) have become a dominated benthic substrate and in Burmanullah, sponges (19.50%) have taken over much of reef space. Observation of multispecies domination of macroalgae in Wandoor and single species domination of sponges in Burmanullah has been established through this study of shallow reefs.

The freshwater apple snail, Pila globosa is one of the most abundant and commercially valued molluscs. Over exploitation of P. globosa for prawn farming is an alarming condition. The present study is aimed at elucidating the breeding behavior and reproduction process of P. globosa. The natural breeding experiment was conducted in two ponds- a 52 decimal pond in Gopalgonj sadar and a 40 decimal pond in Kotalipara. The ponds were prepared by applying lime at the rate of 3 kg/decimal and then filled up with water up to 30cm. Wild snails were stocked at the rate of 600 no./decimal. Organic compost (cow-dung, mustard oilcake and urea at the ratio of 1:1:0.5at the rate of 2.5 kg/decimal respectively) spread throughout the pond. Several male and female specimens were collected from experimental gher and brought to the laboratory aquarium to observe their breeding behavior. At the bottom of aquarium substrate like plastic bottle, marbel, artificial tree etc. were provided for egg laying. Breeding involves three processes: copulation, fertilization and laying. Copulation occurs in water on moist land and it takes about 3-4 hrs, then both separated. Fertilization is internal in P. globosa. Egg laying started 2 or 3 days after copulation. They lay eggs in sheltered places or moist land near water in the dyke. A single female lays eggs average 387.89±167.65 no. per clot at a time. The time elapsed between the first and the last hatchings ranged from 6 to 25 days and for 80% of the 5 egg masses were studied. Considering all the eggs in the egg masses (n=1856) more than 60% of the eggs hatched within 13 days of the first hatching. It needs about 25 days for full clot to be hatched. In the laboratory condition hatching success was observed about 80%.

Data on the dynamics of encrustation of experimental constructions of concrete and marbly limestone with the molluscs Mytilus galloprovincialis Lam. and Mytilaster lineatis Gmel. in the course of the first year of exposure are obtained. It is established that the biopositive properties of the substrate are more strongly associated with its resistance to hydrodynamic action than with the features of the construction material.

A technology has been developed and tested on an industrial scale for the restoration of disturbed lands contaminated with alkali-containing sludge waters. In the process of field research, the use of various neutralized soil neutralizers in the area adjacent to the alumina sludge storage facility was verified. Tests confirmed that the most effective neutralizer of alkaline soil is ammonium sulfate, which reduces the pH of the aqueous extract from 10,2 to 8,2 units. Using non-toxic technogenic materials, substrate compositions have been developed to restore the potentially fertile layer and the technology of ecological rehabilitation of disturbed lands for their subsequent use has been tested.

Microorganisms, in the most hyperarid deserts around the world, inhabit the inside of rocks as a survival strategy. Water is essential for life, and the ability of a rock substrate to retain water is essential for its habitability. Here we report the mechanism by which gypsum rocks from the Atacama Desert, Chile, provide water for its colonizing microorganisms. We show that the microorganisms can extract water of crystallization (i.e., structurally ordered) from the rock, inducing a phase transformation from gypsum (CaSO4·2H2O) to anhydrite (CaSO4). To investigate and validate the water extraction and phase transformation mechanisms found in the natural geological environment, we cultivated a cyanobacterium isolate on gypsum rock samples under controlled conditions. We found that the cyanobacteria attached onto high surface energy crystal planes ({011}) of gypsum samples generate a thin biofilm that induced mineral dissolution accompanied by water extraction. This process led to a phase transformation to an anhydrous calcium sulfate, anhydrite, which was formed via reprecipitation and subsequent attachment and alignment of nanocrystals. Results in this work not only shed light on how microorganisms can obtain water under severe xeric conditions but also provide insights into potential life in even more extreme environments, such as Mars, as well as offering strategies for advanced water storage methods.

Wetland soils of the Maputaland Coastal Plain do not exhibit the redox morphology typically associated with extended periods of water saturation. The aim of this paper was to determine if the addit...

The paper deals with the study results of the Hydrangea species reproduction by green and lignified cuttings based on the collection of the South-Ural Botanical Garden-Institute of the Ufa Federal Research Centre of the Russian Academy of Sciences. The purpose of the work is to study the reproduction by cuttings of species and varieties of the genus Hydrangea and to identify optimal environmental conditions for the most effective result of cuttings. During the experiments green cuttings were rooted in 5 different types of substrates (sand, peat, a mixture of sand and peat, a mixture of sand and perlite, a mixture of peat and perlite). As rooting stimulants Kornevin and Heteroauxin were used. The reproduction of Hydrangea by lignified cuttings was studied after various storage methods during winter. It was found that the maximum rooting percentage is obtained when peat is used as a substrate (rooting reaches 96,7%). The maximum root-forming ability when reproduced by green cuttings using rooting stimulants (Kornevin and Heteroauxin) was observed in H. arborescens (86,6-93,3%) and its varieties (79,8-96,5%). High results were obtained when tree hydrangea was reproduced by both green and lignified cuttings. The root-forming ability of lignified cuttings increases when they are stored during winter under snow.

Aquaponics is amethod of food production that integrates two types of cultivation in one unique place. Fishes and plants can be cultivated in this system, where the fish are maintained in recirculating aquaculture system and the plants in hydroponics (cultivation of vegetables without soil). In order to demonstrate that aquaponics is an alternative for the cultivation of vegetables and also a possibility of water treatment, the objective of the present study was to evaluate the water quality of an aquaponic system composed by lettuces (Lactuca sativa) and lambari fishes (Astyanax bimaculatus). Additionally, we evaluated which is the best civil construction residue (gravel, brick and expanded clay) for lettuce cultivation. The microbiological and physical - chemical monitoring of the system was carried for 42 days, and water from the fish tank was analyzed every 15 days, in the decanter, in the sump tank and in the cultivation bed. The microbiological analyzes consisted in total and thermotolerant coliforms and heterotrophic mesophilic count. For physical – chemical parameters, we analyzed pH, Dissolved oxygen (DO), Toxic Ammonia and Nitrite. Additionally, the development of lettuce in the three different civil construction residues was determined by the average total weight, average leaf mass and average root mass of the plants. We concluded that there was total and thermotolerant coliforms in all the stages of the collection. There was a better growth of the lettuce in the substrate of broken brick, followed by expanded clay and finally by crushed stone.

Due to the importance of further disposal of olive mill waste sludge (OMW) on cultivated soils as an alternative way of their handling, as well as to the properties of natural zeolite clinoptilolit...

Water quality management is important in cage culture of the Asian swamp eel (Monopterus albus). However, it is difficult to manage water quality after a large number of eels have died within the cages. The present study seeks to solve this problem by establishing a method to judge and maintain water quality. To this end, the effect of temperature and eel body weight on the water quality and microorganisms after the death of Asian swamp eels have been examined in the laboratory. The results showed that the changes in water quality parameters were similar at different temperatures and different eel weights. For example, at 26°C, the water quality started deteriorating at 5–7 days after death, which corresponded to the oxygen consumption stage. This was followed by the anaerobic decomposition stage at 11 days after death, at which point the self‐purification process of the water body was initiated. Under a lower temperature of 18°C, the oxygen consumption stage and, therefore, the overall decomposition process were extended. Proteobacteria, Bacteroidetes and Verrucomicrobia were the dominant phyla detected during the decomposition process, but the relative proportions of the dominant families differed across the stages. Based on these findings, we have provided innovative suggestions for water quality detection and management in Asian swamp eel production: (i) at a water temperature of 16–23°C, the following measures should be taken to deal with dead eels 15 days after the introduction of seedlings: (a) at an ammonia nitrogen level higher than 2 mg/L, the bodies present at the bottom of the cage need to be fished out with a net. However, when the ammonia nitrogen level is not higher than 2 mg/L, the whole cage should be sprayed with detoxifying substrate improver or Bacillus powder, according to the instructions, to improve water quality. (ii) At a water temperature of 23–30°C, the above measures should be taken on the 6th day after the seedlings are released, provided the critical value of ammonia nitrogen is 1.57 mg/L. An important limitation of this study is that water exchange was not possible under the laboratory experimental conditions, and the deterioration of water quality caused by eel death may have been alleviated due to water exchange between the inside and outside of the cage.

In order to optimize lime plasters for conservation purposes, the influence of animal glue on the mineralogical evolution, mechanical properties, and weathering resistance was studied. The organic additive caused a decrease in carbonation rate and affected mechanical properties negatively, facilitating the formation of large air bubbles in the plaster matrix. However, the weathering resistance (water spraying/SO2 exposure) improved significantly. The organic additive also reduced crack formation and formed a physical barrier around the calcite crystals, which delayed sulfation. Lime-based composite materials are a valuable alternative to conventional lime plasters, showing improved adherence to the substrate and no significant color changes.

The usage of natural sorbents in sewage water treatment technologies, in particular agro-industrial complex, has a number of environmental and economic advantages. Non-traditional sorbents, which are concentrated in many parts of Ukraine, are cheap raw materials for sewage water treatment. The sorption properties of the upland and lowland peat species of the Gamaliivka-Grybovychi deposit, which were studied early, indicate their high sorption capacity for ammonium ions, which, if they enter water bodies, cause a number of environmental problems. According to the results of the ecological assessment of sewage water of meat processing facility, the chicken processing facility and milk processing plant, it was found out the exceedance of the acceptable limits for the content of ammoniacal nitrogen, respectively: 1.3–3 MPC; 3.8 MPC and 2.5 MPC. This component is a water pollutant and a “crop” of yield in agriculture, since nitrogen is an important element of plant nutrition. The rational usage of natural resources involves the complex usage of natural resources. The nitrogen absorbed by ammonium peat, as well as the peat itself is a sufficient fertilizing land, so the use of used peat complex in agriculture allows to solve not only problems of fertilizers, but also to achieve greening in sewage water treatment technologies. Greening as a whole is a result of waste minimization, and today there are two main areas: new technological non-waste technology together with low-waste technology and waste regeneration. This paper presents a comparison of the physiological indices of plants, depending on the application of the species and form of Gamaliivka-Grybovychi peat deposit, Yavoriv district, when fertilizing the substrate (sand as a background) of the study areas. The influence on the quality of ascent and growth of vegetative culture – watercress, natural form of the top and lowland peat species, as well as their waste forms obtained as a result of the process of purification of ammonium ions, modeling the sewage water of the agro-industrial complex, was investigated. The mass of the harvest from the experimental fields was determined and compared. The differences of lowland and upland peat species are due to its origin, which significantly affects their chemical composition. The plants fuelled with peat are much higher in the mass than those crops that were grown with adding of peat substrate into the lowland. However, the used form of lowland peat provided a 1.57 times higher harvested crop yield than the used upland sample of the studied sorbent.

Application of magnetically treated water to seedlings production has shown beneficial results in several crops. The objective of study was to evaluate the effect of magnetically treated water on germination, growth and development of eggplant seedlings. Three experiments were conducted and the water was treated with 1000 G magnetic field during 24 h. In the first experiment, the treatments tested were applications of magnetically treated water and magnetically untreated water in trays filled with soil and commercial substrate. In the second experiment, the same water treatments were applied, but the trays were filled only with commercial substrate. In the third experiment, two factors were tested, the water treatments (magnetically treated water and untreated water) and two water replacement frequencies (daily and every two days), and the plastic cups were filled with only commercial substrate. In the first experiment, the magnetic treatment of the irrigation water contributed with the growth of the seedlings. However, in the second and third experiments that were conducted on substrate, there was growth reduction of eggplant seedlings with application of magnetically treated water. There were more occurrences decreasing than increasing of substrate water evaporation with the magnetically treated water. There were no significant differences for the seedling growth under different irrigation frequencies. Key words: Germination, magnetism, seeds, Solanum melongena L.

Commercial producers of containerized ornamental plants almost exclusively use soilless media as the substrate for growing the plants. Soilless media are composed primarily of organic materials as opposed to mineral soils. Significant amounts of pesticides can leach from pots containing soilless media to which pesticides have been added as drenches or top-dressings. One of the goals of this project was to identify whether individual components comprising soilless media have differing affinities for the pesticides acephate, imidacloprid, metalaxyl, and plant growth regulator paclobutrazol. One-point 24 h equilibrium sorption assays were conducted to characterize sorption of the pesticides to sand, perlite, vermiculite, coir, peat, pine bark, and aluminum-water treatment residuals (Al-WTRs). Five-point isotherms were then constructed for the more sorptive peat and pine bark substrate components, and for the Al-WTRs. Results indicated significant differences in pesticide behavior with each substrate. Sorption of acephate to most of the substrate components was relatively low, comprising 21–31% of the initial amounts for soilless media components and 63% in Al-WTRs. Al-WTRs were highly sorptive for imidacloprid as evidenced by a partition coefficient of KF = 3275.4 L kg–1. Pine bark was the most sorptive for metalaxyl-M with a measured KF = 195.0 L kg–1. Peat had the highest affinity for paclobutrazol (KF = 398.4 L kg–1). These results indicate that none of component of soilless media has a universally high attraction for all of the pesticides studied.

Greenhouse experiments were conducted to evaluate the utilization of compost derived from grape fruit waste (GFW) as an ingredient in nursery substrates for germination and development of c...

The discharge of city tail water in China has aggravated the pollution of rivers, lakes, and groundwater. Compared with other methods, ecological treatment has advantages in cost and effect. Based on the review of literature, the water quality of city tail water in China was analyzed, and the treatment of city tail water by constructed wetlands (CWs), ecological pond, and ecological floating bed (EFB) was discussed. The pollution indicator concentration of city tail water is higher than that of class IV water standards for rivers and lakes. The maximum removal rates of NH4+-N, TP, and TN in city tail water by CWs are more than 85%. The EFB technology plays an important role in the treatment process of city tail water, and the proportion of substrate treatment is higher in substrate, plant, and microorganism. The economic value of plant is also an important issue to be considered in EFB treatment of city tail water. There are many researches on the single technology of EFB, CWs, and ecological pond for the treatment of city tail water, but the comprehensive technology research of two or more is lacking. This study is of great significance to promote the ecological treatment of city tail water.

Trace elements in freshwater bivalve shells are widely used for reconstructing long-term changes in the riverine environments. However, Northern Eurasian regions, notably the European Russian North, susceptible to strong environmental impact via both local pollution and climate warming, are poorly studied. This work reports new data on trace elements accumulation by widespread species of freshwater mussels Unio spp. and Anodonta anatina in the Severnaya Dvina and the Onega River Basin, the two largest subarctic river basins in the Northeastern Europe. We revealed that iron and phosphorous accumulation in Unio spp. and Anodonta anatina shells have a strong relationship with a distance from the mouth of the studied river (the Severnaya Dvina). Based on multiparametric statistics comprising chemical composition of shells, water, and sediments, we demonstrated that the accumulation of elements in the shell depends on the environment of the biotope. Differences in the elemental composition of shells between different taxa are associated with ecological preferences of certain species to the substrate. The results set new constraints for the use of freshwater mussels’ shells for monitoring riverine environments and performing paleo-reconstructions.

Pentelic marble is considered a valuable material in architecture and was the material of choice in antiquity. Today, on account of the polluted atmosphere in urban areas and other environmental factors, granular disaggregation (sugaring) is noticed on the surfaces of many monuments and buildings constructed with pentelic marble. Consolidation of these surfaces is thus necessary to preserve our architectural heritage. To this purpose, naturally weathered pentelic marble specimens from the Acropolis area in Athens, exhibiting granular disaggregation, were selected and studied. Two different materials, a suspension of traditional lime (“reinforced lime”), and a novel alcohol-based nano-dispersion of calcium hydroxide, with and without the addition of sodium stearate, were applied and evaluated as possible consolidation materials. The specimens were examined prior and after the consolidation treatments, in terms of morphological, chemical and chromatic characteristics, through stereomicroscopy, scanning electron microscopy (SEM–EDX), infrared spectroscopy (FT-IR) and colorimetry. The mass gain of each specimen on account of the consolidation treatment was evaluated. The different consolidation treatments were further assessed through sonication tests, to investigate the degree of adhesion with the substrate and the consolidation efficiency, as well as through static contact angle measurements, aiming to investigate a possible modification of the marble surface. The use of nanolime seems to outperform the traditional application of reinforced lime, in terms of consolidation efficiency, as well as applicability of treatment (4 spray application in contrast to 40), while the addition of sodium stearate seems to reduce micro-cracking and results in a more homogenous marble surface.

Two newly-discovered specimens of the fish locomotion trace Undichna (U. britannica and Undichna isp.), are described from the Middle Devonian Achanarras Limestone Member (Caithness Flagstone Group, NE Scotland). Fish trace fossils have not previously been reported from the Achanarras Limestone Member, despite decades of study of the unit as a key locality for fish body fossils. The traces comprise discontinuous sinusoidal grooves; one showing multiple parallel incisions, created by the fins of an acanthodian fish swimming close to the substrate. The apparent absence of trace fossils attributable to infaunal or epifaunal benthic organisms suggests that the sediment at the bottom of the lake was relatively inhospitable. The low ichnodiversity of the Achanarras Limestone Member is likely due to low oxygen levels in the depositional environment.Thematic collection: This article is part of the Early Career Research collection available at: https://www.lyellcollection.org/cc/SJG-early-career-research

Herein we report the high mortality of larval Hurter's spadefoot toad (Scaphiopus hurterii) tadpoles when fed dry powdered feeds. The evidence implies that dry powders remain suspended in the water column where they enter and clog the filtering apparatus of the tadpoles. When the same foods were wetted to a paste and dropped into the aquaria as a moist pellet, the ration fell directly to the substrate and did not become suspended in the water column. Mortalities of tadpoles fed dry powdered rations were severe, whereas mortalities when fed wetted feed were inconsequential. We recommend that that rations made of ground or powdered components not be fed unless first wetted. Further, we speculate that sediment and siltation of natural waters may contribute to amphibian losses via the same mechanism.

This work aimed to characterize the biochar produced from residues of coconut fruit and to evaluate how it might beneficially alter the retention capacity of water and nutrients in soils with a sandy texture. The biochar was produced in a retort furnace and later analyzed to determine its chemical and physical characteristics. Experiments to analyze the retention potential of the biochar for water and nutrients were performed in PVC columns filled to a 400 mm depth, with the upper 300 mm receiving treatments that consisted of 0, 1, 2, 3, 4, and 5% (p p-1) biochar mixed with soil. For the nutrient retention experiment, in addition to the biochar concentrations, the treatments received the same NPK fertilization. The experiments were performed in a completely randomized design with four replications. The water retention in the upper 300 mm, as well as the pH, effective cation exchange capacity (ECEC) of the substrate, base saturation, and concentrations of P and K, increased with increasing biochar concentration. Coconut biochar demonstrated potential for increasing water retention and improving nutrient retention in sandy soils. This work aimed to characterize the biochar produced from residues of coconut fruit and to evaluate how it might beneficially alter the retention capacity of water and nutrients in soils with a sandy texture. The biochar was produced in a retort furnace and later analyzed to determine its chemical and physical characteristics. Experiments to analyze the retention potential of the biochar for water and nutrients were performed in PVC columns filled to a 400 mm depth, with the upper 300 mm receiving treatments that consisted of 0, 1, 2, 3, 4, and 5% (p p-1) biochar mixed with soil. For the nutrient retention experiment, in addition to the biochar concentrations, the treatments received the same NPK fertilization. The experiments were performed in a completely randomized design with four replications. The water retention in the upper 300 mm, as well as the pH, effective cation exchange capacity (ECEC) of the substrate, base saturation, and concentrations of P and K, increased with increasing biochar concentration. Coconut biochar demonstrated potential for increasing water retention and improving nutrient retention in sandy soils.

The objective of this work is to determine the co-digestion ratio of water hyacinth and cow dung for the optimization of biogas production at Sô Ava, a lake city of Southern Benin. To achieve these ratios, we suppose that the water hyacinth has a high gas yield and cow dung ensures stability in the biodigester because it brings fresh bacteria and has a strong buffering capacity (maintenance of a stable pH). For 45 days, we have introduced a mixture of water hyacinth and cow dung in 5 mini-biodigesters of 10 liters each: digester no1 (100% of cow dung); digester no2 (100% of the water hyacinth); digester n° 3 (50% of the water hyacinth and 50% of the cow dung); digester no4 (75% of cow dung and 25% of water hyacinth); digester no5 (75% of the water hyacinth and 25% of the cow dung). The measurements of the pH, temperature and the proportion of gas (CH4, CO2, O2 and H2S) in the mini-biodigesters was done. The measurements show that the digester n° 5 produces the highest capacity of 15.24L of biogas with 70% of methane while the digester n °2 has the lowest capacity 5.47L of biogas with 58% methane. These results show that the yield of biogas produced is greater when using the mixture of the substrate with the ratio of 75% of water hyacinth and 25% of cow dung. This result encourages the energy recovery from water hyacinth, once considered as a seasonal plague which hinders navigation of local boat in the lake.

Despite the economic and ecological importance of corals’ skeletal structure, as well as their predicted vulnerability to future climate change, few studies have examined the skeletal mechanical properties at the nanoscale. As climate change is predicted to alter coral growth and physiology, as well as increase mechanical stress events (e.g., bioerosion, storm frequency), it is crucial to understand how skeletal mechanical properties change with environmental conditions. Moreover, while material properties are intimately linked to the chemical composition of the skeleton, no previous study has examined mechanical properties alongside carbonate geochemical composition. Using Porites coral cores from a wide range of reef environments (Thailand, Singapore, Taiwan), we correlated coral’s micro-mechanical properties with chemical composition. In contrast to previous mechanical measurements of reef-building corals, we document unprecedented variability in the hardness, stiffness, and micro-cracking stress of Porites corals across reef environments, which may significantly decrease the structural integrity of reef substrate. Corals from environments with low salinity and high sedimentation had higher organic content and fractured at lower loads, suggesting that skeletal organic content caused enhanced embrittlement. Within individual coral cores, we observed seasonal variability in skeletal stiffness, and a relationship between high sea surface temperature, increased stiffness, and high-density. Regionally, lower Sr/Ca and higher Mg/Ca coincided with decreased stiffness and hardness, which is likely driven by increased amorphous calcium carbonate and skeletal organic content. If the coral is significantly embrittled, as measured here in samples from Singapore, faster erosion is expected. A decrease in skeletal stiffness will decrease the quality of reef substrate, enhance the rate of bioerosion by predators and borers, and increase colony dislodgement, resulting in widespread loss of structural complexity.

Rainwater harvesting brings various desired environmental and social benefits in urban development. Tanks in rainwater harvesting systems need low-maintenance and low-cost approaches to manage water quality, especially for scattered small rainwater tanks associated with complex terrains in mountainous cities. Four rain barrels were set up to store roof runoff at the campus of Chongqing University, Chongqing, China. Barrel 1 (B1) and barrel 2 (B2) stored the first-flush water and the roof runoff with first-flush water diverted, respectively, while barrel 3 (B3) was loaded with a biological ceramsite and barrel 4 (B4) used biological ceramsite as a substrate media and planted with Cyperus alternifolius (C. alternifolius) to treat the first-flush water. The performances of the rain barrels were evaluated as well as the variations in water quality parameters were examined. The removal efficiency of B3 was 48.2%, 76.0%, 44.3%, and 24.6% for COD, NH4+–N, TN, and TP, respectively, while B4 had removal efficiencies of 93.4%, 71.0%, 75.0%, and 76.5% for COD, NH4+–N, TN, and TP, respectively. B4 had BOD, NH4+–N, TN, and TP concentrations within the class III Chinese Standard requirement after a storage period of about 240 days. Furthermore, the turbidity in B4 kept dropping. Thus, B4 is a more promising alternative for water quality management in mountainous cities of China.

A new rugose coral-cystoporate bryozoan association is here described from the Devonian of NW Spain. This is the first evidence of intergrowths between Devonian rugose corals and bryozoans. In this case bryozoans provided a suitable substrate for the settlement of corals, which were subsequently encrusted by the bryozoans. The hypothesis of intergrowth between living organisms is supported by the absence of encrustation of the rugose coral calices by the cystoporates. We suggest that the association was specific and developed through chemical mediation. This symbiosis was facultative for the bryozoans but likely not for the corals. The association provided the bryozoan host with additional substrate for encrustation as well as protection from various predators, and it allowed the rugose corals to grow in a muddy environment and benefit from the feeding currents of the bryozoans.

The effectiveness of new nutrient sources has been evaluated with the aim of replacing traditional fertilizers used in agricultural production, favoring sustainability actions. In order to evaluate agronomic efficiency, the objective of this study was to test whether alternative sources of potassium (K) from calcined Glauconite can be used for production of calla lily crop. The effects of 3 K sources (fresh Glauconite, granulated calcined Glauconite and powdered calcined Glauconite) at 4 K rates (0, 205, 410 and 820 mg dm−3) and potassium chloride (KCl) at 1 K rate (410 mg dm−3), on aboveground plant growth and nutrient composition was evaluated in 2 substrates (natural soil and soil added with 30% (v/v) cattle manure). After 180 days of cultivation, application of granulated calcined Glauconite and powdered calcined Glauconite yieled better plant growth compared to application of fresh Glauconite, and these sources at 410 mg dm−3 were equivalent to plant growth in the KCl treatment. The use of soil as a substrate plus cattle manure yielded better plant growth than plants cultivated with soil. Thus, it is indicated that the tested alternative sources are efficient in supplying the calla lily crop with K, Ca and N.

Dolomite and a micronutrient fertilizer are routinely incorporated into a pine bark-based soilless substrate when producing containerized nursery crops, yet the effect of these amendments on phosphorus (P) is not well understood. The objective of this research was to determine the effect of dolomite and micronutrient fertilizer amendments on P partitioning among four P fractions (i.e., orthophosphate-P EOM non-orthophosphate dissolved P [NODP], total dissolved P [TDP], and particulate P (PPJ) and to model potential P species in leachate of pine bark substrate. Amendment treatments incorporated into bark at experiment initiation included (1) a control (no fertilizer, dolomite, or micronutrient fertilizer), (2) controlled-release fertilizer (CRF), (3) CRF and dolomite, (4) CRF and micronutrient fertilizer, or (5) CRF, dolomite, and micronutrient fertilizer. Phosphorus fractions in leachate of irrigated pine bark columns were determined at eight sampling times over 48 days. Amending pine bark with dolomite and micronutrient fertilizer reduced leachate OP concentrations by 70% when averaged across sampling dates primarily due to retention of OP in the substrate by dolomite. The NODP fraction was unaffected by amendments, and the response of TDP was similar to that of OP. Particulate P was present throughout the study and was strongly correlated particulate Fe and DOC concentrations. Visual MINTEQ indicated MnHPO4 and Ca-5(PO4)(3)(OH) were consistently saturated with respect to their solid phase in treatments containing CRF. Results of this study suggest amending pine bark with dolomite and micronutrients is a best management practice for reducing P leaching from containerized nurseries. Virginia Agricultural Experiment Station of the National Institute of Food and Agriculture [SCRI 2014-51181-22372]; Hatch Program of the National Institute of Food and Agriculture [SCRI 2014-51181-22372]; US Dep. of Agriculture; Horticultural Research Institute; Virginia Nursery and Landscape Association The authors thank Julie Brindley, Velva Groover, Anna Birnbaum, and Doug Sturtz for technical assistance, as well as Pacific Organics for donating pine bark for this research. Funding was provided by the Virginia Agricultural Experiment Station and the Hatch Program of the National Institute of Food and Agriculture (including SCRI 2014-51181-22372), the US Dep. of Agriculture, the Horticultural Research Institute, and the Virginia Nursery and Landscape Association. Public domain – authored by a U.S. government employee

The continuous search for peat substitution by local available organic materials, to reduce horticulture industry environmental foot-print, is growing worldwide. In Mediterranean region, Acacia melanoxylon bark is an abundant waste material from non-native tree species control actions, lacking suitable disposal. This study explores the potential use of A. melanoxylon bark as an alternative material for container media. Bark anatomy was characterized, the effect of different bark sieve sizes (4, 6, 8, and 10 mm) and the ageing treatment among successive periods of time (at 0, 4 and 8 weeks) were evaluated regarding substrate physical and chemical performance, as well as phytotoxic effect on tested seeds. Fresh bark was phytotoxic (cress root index 99%). Ageing process may motivate Nitrogen immobilization which raises pH (up to 6.2) and dropped electrical conductivity (minimum of 14 mS m−1), however initial substrate amendment is required prior to potting, thus providing enough nutrients according to microbial-plant needs. Physical substrate performance was strongly correlated with particle size distribution: coarse bark (10 mm) increase air filled porosity, enhancing substrate aeration, while fine bark (4 mm) retain equal water content as commercial peat. Aged A. melanoxylon bark can be blended up to 50% with peat and produce plants as great as in commercial peat-based substrates.

Muriate of potash (MoP) is generally applied in soil for supplementing potassium (K) in agricultural soil; though MoP has some disadvantages as K-fertilizer especially under humic agro-climatic condition. In this context, mica waste (MW) could be a potential alternative for K supplementing in soil. However, slow K-releasing nature limits its application as K source in agricultural soil. In this study, humic substrates (HS) were externally applied along with MW for hastening its rate of K release in soil. Application of HS and MW combination significantly (P < .05) increased K availability in soil. A pot study revealed that the combination of HS with even half of the recommended K in the form of MW sustained plant growth and recorded at par exchangeable K content in soil as compared to recommended MoP treatment. The scanning electron microscopy and x-ray diffraction revealed the changes in the crystal structure of HS-treated MW, and that might be attributed to the enhanced release of K from MW. Based on the observations, it could be concluded that application of HS at 7.5 kg HS ha−1 hastened K release from MW to support the plant growth even after supplementing half of the recommended amount of K through MW. This controlled experiment established the potential of HS-treated MW as an alternative K source in agricultural soil. However, it also implied that a field experiment is necessary to optimize the combination of MW and MoP as an integrated K management treatment for a specific agroclimatic condition.

Container technology can effectively control soil environment and nutrient status to obtain the optimal plant growth condition. Peat, green waste compost (GWC), soil and perlite were used as substr...

The crustose calcareous alga, Ramicrusta textilis Pueschel and G.W. Saunders (Peyssonneliaceae, Rhodophyta), was recently observed to overgrow dead and living corals in shallow lagoon patch reefs of Dongsha Atoll, South China Sea. DNA barcoding revealed that R. textilis frequently co-occurred in a complex with other crustose algae of the family Peyssonneliaceae and the genus Lobophora, forming patchy crusts that cover 3%–29% of the benthic substrate. This is the first record R. textilis overgrowing corals in the Pacific Ocean.

Massive coralla representing the tabulate coral Agetolites occur on a lime mudstone bed in the Upper Ordovician Xiazhen Formation of southeastern China. Other fossils include solitary rugose corals, bryozoans, trilobites, and mollusks. In addition, abundant spicules and spicule networks suggest that sponges were widespread. The occurrence of intact, unabraded fossils in micritic matrix and the absence of high-energy sedimentary structures indicate deposition in low-energy conditions. Thin section analysis of disoriented specimens demonstrates that geopetal indicators are consistent with stratigraphic “up” and differ from the growth axes of the corals, implying that geopetal infillings formed after disorientation. The growth axes of coralla were not redirected during life, suggesting that the corals were either dead at the time of disorientation or died as a result of disorientation. An examination of cyclomorphism indicates that the corals died at different times, rather than during a single event. A close association between sponges and corals is suggested by the presence of spicule networks in calices and intracorallum spaces of Agetolites. It is hypothesized that disorientation of corals was related to growth on biodegradable substrates. We suggest that many coral larvae settled on sponges that formed “sponge meadows”. Disorientation of the resulting corals may have occurred when (1) a host sponge could no longer support the weight of a coral and collapsed, (2) increasing weight or imbalance of a coral caused it to fall off the sponge, or (3) a coral became detached when the sponge died and decomposed. If the coral was alive, sudden deposition in a disoriented position within muddy sediment resulted in its death. Disorientation of massive skeletons, such as colonial coralla, is most commonly attributed to water energy. This study suggests that ephemeral substrates may have been involved in some cases.

Nitrification is simulated in existing water quality models by multiplying the rate with the attenuation factors for water temperature and dissolved oxygen. The effect of pH, substrates and bacteria is mostly neglected. Moreover, the two-step nitrification is simplified to a one-step process. The aim of this study is to investigate the kinetics of two-step nitrification and to simulate this process. Consequently, the importance of considering the effect of pH, substrate and bacteria in nitrification modelling of river basins is emphasized. For this, an experiment was performed on water taken from the Tay Ninh River in Vietnam. The results show a low actual ammonium oxidation rate in the water column of the river. The ammonium oxidation is completely inhibited at pH 5 while the nitrite oxidation is strongly inhibited at pH 8.5. In comparison to the ammonium oxidizers (AOB), the nitrite oxidizers (NOB) are rarely inhibited at low pH. Numerical simulation of the experiment delivered ammonium oxidation rates kA and nitrite oxidation rates kN for different pH values. The kA for pH values lower than 6 is very low. It increases rapidly as the pH increases from 6 to 6.5. We also found out that pH values of 7.5 and 7 are optimal for the activity of AOB and NOB, respectively. Our results emphasize the importance of considering the effect of pH, substrate and bacteria on the nitrification research in river basins. In doing so, nitrification can be simulated more realistically and sustainable water management can be carried out more successfully.

Different proportions of tomato waste compost (TWC) were combined with peat moss and vermiculite as growth substrates used to evaluate the quality of seedlings of economic vegetables, including tom...

The object of the research is technogenically transformed aquatic ecosystem which helps to develop water protection measures and ensure the ecological safety of technogenically conditioned ecosystems of rivers passing through urban areas within aviation repair facilities. The conceptual model of aquatic ecosystem consists of the Nyvka and Irpin rivers, both aquatic ecosystems belong to the Dnieper basin, and the permanent trophic connection makes it possible to consider them as the conceptual majority of interconnected constituents. The aim of the work: to study main features of the formation of technogenically conditioned water ecosystems of small and medium rivers due to anthropogenic influence of the aviation repair facilities. Methods: were used a biotesting method, a method of the complex water quality assessment, a substrate biological transformation model based on the law of non-linear mathematical model of Mono and Michaelis-Menten. The technogenic impact index for every pollutant was calculated. Results: it was found the content of heavy metals, oil products, nitrogen, nitrite nitrogen, nitrate nitrogen in the surface water of the Nyvka and Irpin rivers. Investigated samples of the Nyvka water were of V water quality class and the Irpin water was of I V water quality class. The hydrochemical analyze of the Irpin river has shown that limitation factors affecting the water quality, cause the disturbance of the self-remediation ability of the water ecosystem. Was shown changes of contaminant concentration in the Irpin River current. Discussions : obtained results of the modeling of the Irpin water self-remediation from contaminants are represented that the constant for contamination agents such as nitrogen, nitrite nitrogen, nitrate nitrogen and Cu 2+ have negative values. The predominating negative values indicate, that in the aquatic environment self-remediation processes have not time to occur, as water is being very active contaminated from the mowings, neighboring agricultural lands.

The amount of available water in the substrate is one of the most important factors for the growth and development of potted ornamental species. The aim of the present study was to determine the water consumption of Alstroemeria x hybrid variety Firenze when submitted to different irrigation levels and to assess their effects on production factors. The experiment was carried out under controlled conditions of temperature at Colégio Politécnico of Universidade Federal de Santa Maria, in the state of Rio Grande do Sul, Brazil. Rhizomes of Alstroemeria x hybrid variety Firenze were transplanted into 20 liters rigid black plastic pots filled with substrate. Five treatments (90%, 75%, 60%, 45%, and 30% of container capacity) with 10 repetitions were arranged in a completely randomized design. The production components height and flowering stem diameter, number of flowers per stem, and stem fresh and dry matter content were evaluated over a year of production. Our results demonstrated an increase in water consumption as water availability increased, interfering with the production parameters, except for the number of flowers per stem and flower stems diameter.

Jellyfish are a popular public aquarium species, however, their collection from natural populations is undesirable due to impact on species abundance and bycatch. Thus, a sustainable supply of jellyfish bred in-house would be highly desirable. Here we describe an investigation into developing a sustainable moon jellyfish, Aurelia aurita, breeding program by determining the impact of substrate type on reattachment of polyps and the influence of iodine and temperature on strobilation and ephyra production. To test whether reattachment and growth of moon jellyfish polyps are influenced by substrate type polyps were provided with anthropogenic and natural substrates after being dislodged in experimental aquaria. Polyps selectively re-attached to plastics rather than natural materials. However, polyp growth was similar on all tested substrates. We tested whether cooling and addition of iodine affected strobilation. A period of cooling of around 10 °C while also introducing soluble iodine to the polyps enhanced strobilation rate. This method produced ephyra at a reliable rate in captivity negating the need for collection of wild individuals providing a supply of individuals for exhibit and for conservation research within a public aquarium. These results demonstrate that plastics should be adopted as an easier to colonize substrate and the use of cooling with iodine addition can enhance sustainable breeding protocols of moon jellyfish and may be relevant to the production of comparable jellyfish species.

The growing demand for stony corals as ornamental aquarium animals requires defined aquacultural breeding strategies. For the sexual propagation of corals, material substrates are needed, that attract larvae and support their settlement and development. In this study, five types of highly porous ceramic materials were developed following the example of coral skeleton. The applicability of these settlement substrates was tested using larvae of the stony coral Pocillopora damicornis. Partial sintering of pressed clay pellets, freeze casting of clay and alumina-mullite based slurries and direct foaming of high alkane phase emulsified suspensions (HAPES) using alumina were employed. By the addition of mm-sized spherical polystyrene beads as sacrificial templates during freeze casting (alumina-mullite), superficial pores in the size of the larvae were created. The inorganic substrates featured open porosities between 35% (pressed clay) and 83% (foamed alumina), pore sizes ranging from nm to mm-scale and pore morphologies dominated by interparticle porosity (pressed), lamellar pores (freeze casting) and cellular pore types (direct foaming). The ceramic substrates were incubated in artificial sea water for 3 months to induce necessary biofilm formation and algae growth. Afterwards, individual substrates were exposed to 5 coral larvae, and their settlement behavior was monitored over 14 days. At the end of this period, all ceramic materials were successfully accepted as settlement substrates, with a mean settlement rate of 46.2%, and no significant differences between the substrate types. On samples with large surface superficial pores, a significantly reduced survival of settled larvae (79%) compared to the other porous materials (93–98%) was determined, suggesting a non-ideal surface topography. While alumina foam samples (HAPES) exhibit the most promising results in terms of settlement and survival of larvae, clay-based substrates provide a more economic solution for the sexual propagation of corals in aquaculture.

Polymer modified bituminous thick coatings are increasingly used in the construction industry to protect underground parts of buildings from groundwater. When assessing their durability, one vital issue related to their functional properties is the influence of water absorption on the waterproofness of the applied solution as a result of the action of groundwater with different pH values. As part of the research, the water absorption of the products in question was assessed using the method of total immersion in water with pH of 4.0, 7.0 and 7.5 as well as comparatively, as a result of one-way exposure to demineralized water under successively increasing pressure up to 0.5 MPa. The moisture susceptibility of the coatings was assessed both concerning the local surface damage and the continuous waterproofing coating. It was established that the coatings show the highest water absorption when the water pH is 4.0, which simulates the groundwater aggressiveness on construction products. It was proven that moisture absorbed by the coatings is retained within this layer and is not transferred to the substrate on which the coatings are laid. It was also found that water in contact with the tested coatings changes its reaction to alkaline, which can result in contamination of groundwater in the area of waterproofing coating. A modification of the method of assessing the water absorption of polymer modified bituminous thick coatings was proposed, taking into account their use in conditions of use.

The removal of potentially harmful radioactive waste from the anthroposphere will require disposal in geological repositories, the designs of which often favour the inclusion of a clay backfill or engineered barrier around the waste. Bentonite is often proposed as this engineered barrier and understanding its long-term performance and behaviour is vital in establishing the safety case for its usage. There are many different compositions of bentonite that exist and much research has focussed on the properties and behaviour of both sodium (Na) and calcium (Ca) bentonites. This study focusses on the results of a swelling test on Bulgarian Ca bentonite that showed an unusual gel formation at the expanding front, unobserved in previous tests of this type using the sodium bentonite MX80. The Bulgarian Ca bentonite was able to swell to completely fill an internal void space over the duration of the test, with a thin gel layer present on one end of the sample. The properties of the gel, along with the rest of the bulk sample, have been investigated using ESEM, EXDA and XRD analyses and the formation mechanism has been attributed to the migration of nanoparticulate smectite through a more silica-rich matrix of the bentonite substrate. The migration of smectite clay out of the bulk of the sample has important implications for bentonite erosion where this engineered barrier interacts with flowing groundwater in repository host rocks.