Management of excavated soil and dredging spoil waste from construction and demolition within the EU: Practices, impacts and perspectives.

Excavated soil and rock (ESR) and dredging spoils (DDS) account for 23 % of the total EU waste generation in 2020. This study performs a life cycle assessment and life cycle costing to quantify the potential environmental and cost savings resulting from increasing the level of ESR and DDS prepared for reuse and recycled in comparison to the business-as-usual practice. Scenarios for the waste management pathways based on the status quo, technical feasibility or normative impositions are assessed, including the potential contribution to achieving the European Green Deal goals. Results show that promoting preparing for reuse and recycling could lead to non-negligible GHG reductions (up to 3.6 Mt. CO2 eq.) and economic savings (EUR 12.3 billion) annually. Depending upon the scenario, 0.2 % to 1 % of the net annual GHG emissions reductions sought by the European Green Deal could be facilitated by scaling up improved circular management of ESR and DDS at the EU level. Finally, the study highlights the main barriers to scaling up to more circular (i.e., preparing for reuse and recycling) and better performing management options in Europe. The results provide new insights for the European Green Deal and circular economy policymaking for CDW.

Inhibition mechanism of crude lipopeptide from Bacillus subtilis against Aeromonas veronii growth, biofilm formation, and spoilage of channel catfish flesh.

Aeromonas veronii is associated with food spoilage and some human diseases, such as diarrhea, gastroenteritis, hemorrhagic septicemia or asymptomatic and even death. This research investigated the mechanism of the growth, biofilm formation, virulence, stress resistance, and spoilage potential of Bacillus subtilis lipopeptide against Aeromonas veronii. Lipopeptides suppressed the transmembrane transport of Aeromonas veronii by changing the cell membrane's permeability, the structure of membrane proteins, and Na+/K+-ATPase. Lipopeptide significantly reduced the activities of succinate dehydrogenase (SDH) and malate dehydrogenase (MDH) by 86.03% and 56.12%, respectively, ultimately slowing Aeromonas veronii growth. Lipopeptides also restrained biofilm formation by inhibiting Aeromonas veronii motivation and extracellular polysaccharide secretion. Lipopeptides downregulated gene transcriptional levels related to the virulence and stress tolerance of Aeromonas veronii. Furthermore, lipopeptides treatment resulted in a considerable decrease in the extracellular protease activity of Aeromonas veronii, which restrained the decomposing of channel catfish flesh. This research provides new insights into lipopeptides for controlling Aeromonas veronii and improving food safety.

Intraspecific Variability in Trionymus aberrans Goux, 1938 (Hemiptera: Coccomorpha: Pseudococcidae) with Description of the Second-Instar Nymph.

The morphological characteristics of adult females of Trionymus aberrans Goux, 1938 (Hemiptera: Coccomorpha: Pseudococcidae) collected from post-industrial wastelands and other habitats in Poland and other countries were studied. Distinctive morphological variations were observed in the specimens from post-industrial wastelands in Poland. Scanning electron micrographs of the morphological characters of T. aberrans are provided. The presence of unusual pores, each with four loculi, was demonstrated for the first time in a species of Pseudococcidae. The importance of introducing additional morphological characters into the species description is discussed. New data on the frequency and host preferences of T. aberrans are also provided. This research is the first long-term study on scale insect species in post-industrial wastelands. The second-instar nymph of T. aberrans is described and illustrated and the presence of translucent pores on the hind coxae of this developmental stage is reported for the first time.

Characteristics and factors influencing soil organic carbon composition by vegetation type in spoil heaps.

Introduction: The variation of organic carbon content in spoil heaps is closely related to improving soil structure, maintaining soil fertility, and regulating soil carbon cycling balance. Analyzing the soil organic carbon content and related driving factors during the natural vegetation restoration process of spoil heaps is of great significance for promoting the accumulation of soil organic carbon in the spoil heaps. Methods: we selected spoil heaps with the same number of years of restoration to research the variations in soil organic carbon components under different vegetation types (grassland: GL, shrubland: SL, secondary forest: SF) and compared the results with those on bare land (BL). Results: Our results showed that vegetation type and soil depth significantly affect the content of soil organic carbon components. There was no difference in soil organic carbon components between SF and SL, but both were considerably superior to GL and BL (p<0.05), and the particulate organic carbon (POC) and light fraction organic carbon (LFOC) contents of SL were the highest. A significant positive linear correlation existed between SOC and active organic carbon components. Pearson's correlation and redundancy analysis showed that the available potassium (AK) and total nitrogen (TN) contents and gravel content (GC) in the BL soil significantly impacted soil organic carbon. When vegetation is present, TN, total phosphorus (TP), and Fine root biomass (FRB) significantly affect soil organic carbon. Structural equation modelling (SEM) shows that AK and soil moisture content (SMC) directly affect the organic carbon composition content of BL, When there is vegetation cover, fine root biomass (FRB) had the largest total effect in the SEM. Soil bulk density (BD) has a negative impact on soil organic carbon, especially in the presence of vegetation. Conclusion: These findings suggest that vegetation restoration can significantly increase soil organic carbon content, FRB, AK, and TN play important roles in enhancing soil organic carbon. Supplementation with nitrogen and potassium should be considered in the bare land stage, and shrubs nitrogen-fixing functions and well-developed roots are more beneficial for the accumulation of soil organic carbon.

Artisanal gold mine spoil types within a common geological area and their variations in contaminant loads and human health risks.

This study answered the question of whether mine spoils occurring in a common geological location had similarities in their contaminant load and associated health risks. Using inductively coupled plasma mass spectrometry, the total contents of Cd, Pb, As, Hg, Zn, Fe, and Al were determined for 110 digested soil samples obtained from underground rock ore (URS), oxide ore (OXS), and alluvial ore (AVS) mine spoils. Independent sample Kruskal-Wallis test and pairwise comparisons of sources were used to ascertain the variation in elemental load between the mine spoil investigated. The results showed that mine spoil contaminations and their ecological and health risk significantly varied (p < 0.01) from each other and fell in the order OXS > URS > AVS > forest soils because of their geochemistry. Determined enrichment and geo-accumulation indices revealed that OXS and URS sites were severely-extremely polluted with Cd, Hg, and As, while AVS mine spoils were only moderately contaminated by Cd and As contents. Children had the highest tendency for developing noncarcinogenic health defects largely due to toxic contents of As, Cd, and Hg in soil materials near them than adult men and women would after obtaining a hazard index of 73.5 and 67.7 (unitless) at both OXS and URS sites. Mine spoils especially where hard rocks and oxide ores were processed are not fit for agricultural use or human habitation. The restriction of human access and sustainable remediation approaches are required to avert health defects. Even so, area-specific potentially toxic elements must be targeted during soil cleaning due to the significant variations in contaminant load between mined sites.

Short- and long-term assessment of PAH, PCB, and metal contamination in the Belgian part of the North Sea.

Dredging activities can result in the relocation of contaminants such as polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and metals from shipping channels, harbours, and ports into the marine environment where these components may exert a negative effect on the marine ecosystem. In this work, contamination associated with dredging is evaluated at and around dredged spoil disposal sites in the Belgian part of the North Sea, taking into account spatial as well as temporal variation. A homogeneous dispersion of the different contaminants was observed at the different sites. However, the contamination pattern was different for disposal sites that were linked with commercial ports, resulting in significantly higher PAH and PCB concentrations. When comparing concentrations with environmental assessment criteria, contamination of PAHs does not exceed these criteria in the Belgian Part of the North Sea, and for PCBs, only CB118 reveals a concerningly high concentration that exceeds the environmental assessment criteria. This is in contrast with metals where the contamination of As, Cr, Ni, and Zn exceeded the environmental limit values both at dredged spoil disposal sites and reference locations.

Evaluating soil-water conserving performance of land management strategies for spoil tips on the Chinese Loess Plateau.

Surface runoff decrease (SRD) and sediment concentration change (SCC) are accountable for sediment reduction by anti-erosion strategies. Using a design of horizontal stages, contour trenches, fish-scale pits, as well as their combinations, this study evaluated the two components for sediment reduction after the implementation of various land management strategies on steep spoil tips. The study highlighted the interactions between SRD and SCC in reducing sediment, and characterized the temporal variations of sediment-reducing capacity by SRD and SCC. Results showed that slope erosion was well controlled with control ratios of sediment yield ranging from 0.4 to 0.59, 0.2 to 0.22, for horizontal stage- and contour trench-based strategies, respectively. Sediment-reducing benefit by SRD accounted for 52%-77% of the total sediment reduction and highly determined the performance of SCC. Quadratic relationships between sediment-reducing capacity by SCC and that by SRD were observed. The function of SCC only operated when the sediment-reducing capacity by SRD reached a certain threshold. These thresholds varied greatly in the range of 0.75 kg m-3-0.91 kg m-3 and 0.61 kg m-3-0.66 kg m-3 for horizontal stage- and contour trench-based strategies, respectively. The upper limits for sediment-reducing capacity by SCC varied in the range of 0.32 kg m-3-0.44 kg m-3 and 0.63 kg m-3-0.76 kg m-3 for horizontal stage- and contour trench-based strategies, respectively. An efficiency coefficient of 55% and an M-N ratio of 1:1 indicated that sediment-reducing benefits by SRD and SCC were effectively exerted by combining contour trenches and fish-scale pits. The findings emphasized that the application of land management strategies must be considered based on particular goals to restore spoil tips. In practice, if targeted to enhancing sediment-reducing efficiency, contour trenches and fish-scale pits should be primarily considered. However, if the aim is to decrease water consumed for sediment control, then horizontal stages should be principally considered.

Phytoavailability and uptake of arsenic in ryegrass affected by various amendments in soil of an abandoned gold mining site.

Abandoned gold mining spoils pose socio-environmental, human, and animal health impacts and threaten sustainability of mineral extraction. Green trials and ecological solutions are required to effectively remediate these contaminated soils and mitigate the associated risks. Here, we carried out a pot experiment using a highly contaminated soil (mean total As = 5104.0 mg/kg) collected from an abandoned mine spoil in Ghana. We aimed to quantify the impacts of compost, iron oxide, and poultry manure on the mobilization, fractionation, and uptake of As by ryegrass (Lolium perenne). The soil amendments were applied at a rate of 5% (w/w) each, separately or in combination. We extracted the mine spoil soil readily-bioavailable As and specific-sorbed As, and determined the As contents in plant and the uptake after harvest. The plant transfer indices for soil-to-root (bioconcentration factor, BCF), soil-to-shoot (bioaccumulation concentration- BAC), and root-to-shoot (translocation factor- TF) were also calculated. Addition of manure increased the mining readily-bioavailable As by 243% and specific-sorbed As by 38%, as compared to the control. Manure addition further aided root As-uptake by 134%, whilst its combination with compost increased uptake by 101%. Lone addition of manure and in combination with compost resulted in BCF above 1, indicating increased As-phytostability. The presence of carbon and iron in the roots of the ryegrass sorbed or precipitated As limited its soil-to-shoot and root-to-shoot transfer. These findings indicate that manure alone and in combination with compost can be used to augment the phytoremediation efficiency of ryegrass in the As-contaminated spoil.

Influence of water erosion on fire hazards in a coal waste dump - A case study.

Dump fires are a significant environmental problem in post-mining areas. The TEXMIN project has shown that climate change could lead to more extreme weather events in the future, intense precipitation among them. The impact of water erosion on the development of endogenous fires in coal waste heaps has not been investigated thus far. Meteorological data collected from the studied dump area in Libiaz, Poland confirmed that heavy rainfall occurred many times, causing surface erosion on the slope. Gully erosion was observed on the western slope of the heap, the depth of which was up to 1.6 m. Data showed that between areas with and without water erosion, there was a significant difference in measured temperatures and gas concentrations that defined the fire intensity. Erosion facilitated self-heating such that internal temperatures increased to 52.9 °C. Further, at a depth of 1 m in the self-heating zone, maximum gas concentrations were 15.65 vol%. CO2, 10 ppm CO, and 0.435 vol%. CH4, while the O2 concentration dropped below 1.0 vol%. These results show that despite preventative measures, thermal activity reactivated in the vicinity of gully erosion and caused the self-heating zone to expand.

Biochar, compost, iron oxide, manure, and inorganic fertilizer affect bioavailability of arsenic and improve soil quality of an abandoned arsenic-contaminated gold mine spoil.

Arsenic (As) contaminated mining spoils pose health threats to environmental resources and humans, and thus, mitigating this potential risk is worth investigating. Here, we studied the impacts of biochar, compost, iron oxide, manure, and inorganic fertilizer on the non-specifically (readily bioavailable)- and specifically- sorbed As and soil quality improvement of an abandoned mine spoil highly contaminated with As (total As = 1807 mg/kg). Compost, iron oxide, manure, and biochar were each applied at 0.5%, 2%, and 5% (w/w) to the contaminated soil; and NPK fertilizer at 0.1, 0.2, and 5.0 g/kg. The non-specifically (readily bioavailable)- and specifically- sorbed As were extracted sequentially and available P, total C and N, dissolved organic carbon, soil soluble anions, and exchangeable cations were extracted after 1- and 28-day incubation. Compost, manure, and biochar at 5% improved the total C and N and exchangeable K+, Mg2+ and Na+. However, manure, compost, and iron oxide at 5% reduced available P from 118.5 to 60.3, 12.6, and 7.1 mg/kg, respectively. As compared to the untreated soil, the addition of iron oxide doses reduced the readily bioavailable As by 93%; while compost, manure, inorganic fertilizers, and biochar increased it by 106-332%, 24-315%, 19-398%, and 28-47%, respectively, with a significantly higher impact for the 5% doses. Furthermore, compost reduced specifically-sorbed As content (14-37%), but the other amendments did not significantly affect it. The impacts of the amendments on the readily bioavailable As was stronger than on specifically-sorbed As; but these were not affected by the incubation period. Arsenic bioavailability in our soil increased with increasing the soil pH and the contents of Cl-, DOC, and exchangeable K+ and Na+. We conclude that iron-rich materials can be used to reduce As bioavailability and to mitigate the associated environmental and human health risk in such mining spoils. However, the carbon-, and P-rich and alkaline materials increased the bioavailability of As, which indicates that these amendments may increase the risk of As, but can be used to enhance phytoextraction efficiency of As in the gold mining spoil.

Vegetation restoration restricts rill development on dump slopes in coalfields.

Severe rill erosion on dump slopes poses a great threat to the ecological environment in mining areas. Vegetation restoration is an effective measure for controlling soil erosion on dump slopes. However, few studies have identified the long-term influence of vegetation restoration on rill development on dump slopes. Therefore, we investigated the rill development characteristics of dump slopes with three typical restoration models (CK: natural restoration; ED: Elymus dahuricus; and AO: Artemisia ordosica) and three recovery time (1 y, 3 y and 5 y). The results showed that vegetation adequately controlled rill erosion on dump slopes. ED and AO could effectively control the development of rills with widths >15 cm and depths of 10-20 cm. ED vegetation restoration inhibited the development rill morphology and network better than AO. The rill erosion modulus of the ED slope and AO slope decreased by 76.29%-90.77% and 46.66%-61.49%, respectively, compared with that of natural restoration slopes with recovery time of 1 y, 3 y, and 5 y. ED controlled rill erosion better than AO, but this effect gradually weakened with recovery time. Vegetation coverage contributed 34.99% of the total variation in rill morphology and was the main factor affecting the development of rills on dump slopes. Furthermore, vegetation coverage had a more important role in controlling rill development than did the root system on dump slopes. This study provides valuable information for optimizing vegetation construction for soil loss control on dump slopes.

Soils and spoils: mineralogy and geochemistry of mining and processing wastes from lead and zinc mining at the Gratz Mine, Owen County, Kentucky.

Purpose: Mineralogical and geochemical features of mining and processing wastes collected in Owen County, part of the Central Kentucky Lead-Zinc district, were investigated. The Gratz mine, abandoned in the 1940s, is on a dairy farm. Aside from discerning the nature of mining refuse at the site, the investigation was part of the University of Kentucky College of Pharmacy's mission to explore unusual environments in the search for unique microbiological communities. Materials and methods: Four samples of a soil-plus-spoils mix were collected from spoil piles and two samples, the sluice and coarse samples, were closely associated with the site of the ore processing. Optical petrology (polarized reflected-light, oil-immersion optics at a final magnification of 500 ×), X-ray diffraction, X-ray fluorescence, inductively coupled plasma mass spectrometry, field emission scanning electron microscopy (FE-SEM), and high-resolution transmission electron microscope (HR-TEM) with selected area electron diffraction (SAED) and/or microbeam diffraction (MBD), scanning transmission electron microscopy (STEM), and energy-dispersive X-ray spectrometer (EDS) analyses were employed to characterize the samples. Results and discussion: Calcite is the main mineral in most samples, followed by near equal amounts of quartz and dolomite. Sphalerite and galena are the principal sulfides and barite is the dominant sulfate. Geochemistry of major elements reflected the mineralogy, whereas trace elements showed different groupings between the minerals. Scandium, Cu, Ga, Ge, Cd, and Sb were found predominantly associated with Zn and Pb and sulfide minerals; Bi, Hf, In, Sn, and Zr with heavy mineral fraction; while the remaining trace elements, including the rare earths, were mostly distributed among other present phases, i.e., oxyhalides, oxides, silicates, and carbonaceous material. The data were used to illustrate the processes and conditions that control the sulfide-mineral oxidation and its potential for the environmental release of associated reaction products. Conclusions: The wastes represent a potential source of environmentally disruptive concentrations of Zn, Pb, and other sulfide-associated elements. The high share of carbonates suggests near-neutral conditions in deposited wastes, restricting sulfide weathering and further limiting the oxidant activity of Fe. The low-Fe content and its predominant presence in highly resistant hematite also constrain sulfide weathering. Consequently, the spoils have a low potential for generation of acidity and release of heavy metal(loid)s in the surrounding environment.

Bioaugmentation With a Consortium of Bacterial Sodium Lauryl Ether Sulfate-Degraders for Remediation of Contaminated Soils.

The anionic surfactant sodium lauryl ether sulfate (SLES) is the main component of most commercial foaming agents (FAs) used in the excavation of highway and railway tunnels with Earth pressure balance-tunnel boring machines (EPB-TBMs). Several hundreds of millions of tons of spoil material, consisting of soil mixed with FAs, are produced worldwide, raising the issue of their handling and safe disposal. Reducing waste production and reusing by-products are the primary objectives of the "circular economy," and in this context, the biodegradation of SLES becomes a key question in reclaiming excavated soils, especially at construction sites where SLES degradation on the spot is not possible because of lack of space for temporary spoil material storage. The aim of the present work was to apply a bacterial consortium (BC) of SLES degraders to spoil material excavated with an EPB-TBM and coming from a real construction site. For this purpose, the BC capability to accelerate SLES degradation was tested. Preliminary BC growth, degradation tests, and ecotoxicological evaluations were performed on a selected FA. Subsequently, a bioaugmentation experiment was conducted; and the microbial abundance, viability, and SLES concentrations in spoil material were evaluated over the experimental time (0.5, 3, 6, 24, 48, and 144 h). Moreover, the corresponding aqueous elutriates were extracted from all the soil samples and analyzed for SLES concentration and ecotoxicological evaluations with the bacterium Aliivibrio fischeri. The preliminary experiments showed the BC capability to grow under 14 different concentrations of the FA. The maximum BC growth rates and degradation efficiency (100%) were achieved with initial SLES concentrations of 125, 250, and 500 mg/L. The subsequent bioaugmentation of the spoil material with BC significantly (sixfold) improved the degradation time of SLES (DT50 1 day) compared with natural attenuation (DT50 6 days). In line with this result, neither SLES residues nor toxicity was recorded in the soil extracts showing the spoil material as a by-product promptly usable. The bioaugmentation with BC can be a very useful for cleaning spoil material produced in underground construction where its temporary storage (for SLES natural biodegradation) is not possible.

Experimental research on sintering construction spoil bricks based on microwave heating technology.

The accumulation of construction spoil has brought great challenges to urban construction and environmental protection. It is an effective way to solve the problem of construction spoil accumulation by using construction spoil to sinter brick. At the same time, it can also reduce the waste of clay resources and farmland destruction caused by the production of sintered brick. Microwave sintering technology can greatly improve the sintering efficiency of materials. Sintering brick by microwave sintering technology can avoid a series of environmental problems in the traditional production process of sintered brick and can lead to an eco-friendly production of bricks. In this study, construction spoil was used as the raw material, and Al2O3, Fe2O3, and TiO2 powders were studied as MASM for improving the temperature rise rate and sintering efficiency of the brick in microwave sintering process. The characteristics of construction spoil brick sintered by microwave were studied by series experiments including unit weight, compressive strength, and meso-analysis. Results proven that microwave sintering technology is an efficient technology for brick making. The MASM can effectively increase the temperature rise rate of the sample and simultaneously improve the impermeability of the sample and sintering efficiency.

Data on physico-chemical characteristics and elemental composition of gray forest soils (Greyzemic Phaeozems) in natural-technogenic landscapes of Moscow brown coal basin.

Waste rocks material and acid mine drainage (AMD) in sulfur coal mining areas of Moscow brown coal basin lead to significant transformation of landscape components (soils, surface, and groundwaters). Most of the abandoned sulfide-bearing spoil heaps have not been reclaimed and toxic products of their weathering cause the risk of long-term soil contamination. In this article, we report original data on some physico-chemical properties and elemental composition of liquid and solid soil phases, waste dumps and AMD from twо abandoned spoil heaps of the Moscow basin and adjacent territories (the Tula region, Central Russia). Soil samples were collected from each genetic horizon of soil depth profile at sites affected by waste dumps and mine subsidence, as well as at natural sites. Waste material was sampled from the different parts of the spoil heaps. Sampling of AMD was performed in technogenic reservoirs near waste dumps. In displaced liquid phases (by ethanol) from soils and waste dump material, natural superficial waters and AMD pH-value, electrical conductivity (EC), the content and composition of readily soluble salts (by high-performance liquid chromatography (HPLC)), as well as titratable acidity (H+and Al3+) and, water-soluble Fe (using UV/Vis spectrophotometry) were measured. In bulk soil samples organic carbon (Corg), exchangeable cations (Cа2+, Mg2+, H+, Al3+ in KCl-extracts) and hydrolytic acidity (in CH3COONa-extracts) were determined. The obtained data can be used to understand the behavior of сhemical elements in soil profiles polluted by coal mining; the negative impact of mine wastes on soil salinity; when identifying pollution levels of potentially hazardous elements in soils affected by coal mining and for complex remediation of spoil heaps in Moscow brown coal basin.

Acid Generation and Heavy Metal Leachability from Lignite Spoil Heaps: Impact to the Topsoils of Oropos Basin, North Attica, Greece.

The disposal of lignite spoil and tailings poses a major environmental problem in lignite mining sites which is associated with the oxidation of sulfide minerals contained in the primary ore. This process renders acidic effluents. Lignite mining in the Oropos Neogene basin, North Attica, Greece operated since the last century and ceased in the late 1960s. Piles of complex waste material are dispersed close to the mining sites. The high sulfur content and low Net Neutralization Potential, i.e. values < - 20 CaCO3 kg/t in most analyzed waste samples, indicate that the waste is prone to acid generation. The leachates (EN12457) from the lignite spoils showed high concentrations in Ni and Zn exceeding the EU regulatory limits for the non-hazardous wastes. GIS-based geochemical maps of the topsoil showed enrichment in Ni (Cr, V) associated with the regional geogenic enrichment but also local accumulation around the hot spot sites of lignite spoil heaps.

Sea lice Lepeophtheirus spinifer, Tuxophorus sp. and Caligus sp. infections on wild-caught queenfish Scomberoides commersonnianus from northern Australia.

Studies of ectoparasites of wild-caught queenfish Scomberoides commersonnianus from several areas in northern Australia were reviewed to investigate relationships between parasite burdens, environmental conditions and external lesions. A sample of 27 queenfish captured near a dredge spoil disposal site in Gladstone Harbour, Queensland, Australia, in January 2012 was anomalous, with a high percentage of fish (66.6%) exhibiting grossly visible skin lesions including foci of erythema and petechial haemorrhages, particularly on the pectoral girdle and ventrolateral surfaces. Microscopically, lesions comprised acute epidermal erosion, ulceration and/or perivascular dermatitis with dermal oedema and depigmentation. Skin lesions were associated with high prevalence (100%) and intensity (mean = 21.2 copepods fish-1, range 4-46) of infection by sea lice Lepeophtheirus spinifer. Only queenfish infected with >10 L. spinifer presented with skin lesions. This is the first record of L. spinifer from Australia. In contrast, grossly visible skin lesions were not reported from queenfish (n = 152) sampled from other sites in the Northern Territory and Queensland, where the sampled fish had a much lower prevalence (51.3%) and intensity (mean = 3.54, range 0-26) of copepod (L. spinifer, Caligus spp. and Tuxophorus sp.) infections. Copepods from queenfish in studies undertaken outside Gladstone Harbour exhibited an over-dispersed pattern of infection, with the vast majority (n = 137, or 90.1%) of fish infected with <5 copepods. These data demonstrate that heavy L. spinifer infections, combined with poor water quality and/or direct exposure to contaminated dredge spoil and blooms of the cyanobacterium Lyngbya majuscula, can be associated with cutaneous disease in wild-caught queenfish.

Mine spoil remediation via biochar addition to immobilise potentially toxic elements and promote plant growth for phytostabilisation.

There are thousands of disused and abandoned mining sites around the world with substantial accumulations of exposed mine spoil materials that pose a direct threat to their surrounding environment. Management of such sites, and neutralisation of the environmental threats they pose, is therefore extremely important and is an issue of global significance. Low cost management and remediation strategies need to be developed because many abandoned mine sites are in remote and/or economically challenged areas. One promising option is the incorporation of biochar into spoil materials, which has the potential to immobilise leachable toxic constituents and facilitate revegetation and thereby stabilisation of spoil heaps. This study investigated the capacity of readily available biochar materials made from wheat and rice waste products to immobilise and retain key metallic contaminants Pb and Zn from solution, and also investigated the utility of biochar application for remediating mine spoil heaps from different mine types in terms of facilitating establishment of vegetation coverage and minimising porewater element mobility within spoil heaps. The results demonstrated the high sorption capacity of the biochars (typically >97% of Pb or Zn in solution) and their ability to retain the metals despite an active desorption procedure (>93% of sorbed Pb retained and >75% of sorbed Zn). The remediation trial revealed that biochar application increased plant yield and decreased plant assimilation of many potentially toxic elements and also decreased spoil porewater concentrations of Al, Cd, Pb and Zn in most cases. In some spoil types investigated biochar addition also significantly decreased porewater concentrations of As (e.g. from ~30 mg/L to ~5 mg/L), demonstrating its potential utility for low cost environmental remediation across a range of mine spoil types.

Biochar assisted phytoremediation and biomass disposal in heavy metal contaminated mine soils: a review.

Mining activities causes heavy metal pollution and adversely affect the ecological safety and human well-being. Phytoremediation-biochar synergy can effectively remediate mine spoils contaminated with heavy metals (HM). A review which focuses exclusively on the application of biochar assisted phytoremediation in HM contaminated mine spoil is lacking. Mechanisms of metal immobilization by biochar, potential plants and contaminated biomass disposal methods has also been reviewed. Availability of biochar feedstock and production conditions, optimization of application rate, application techniques, selection of suitable hyperaccumulators and cost optimization of bulk biochar production are the key to a successful biochar-based HM remediation of mine tailings and coalmine spoil. Presently, herbs and shrubs are mostly used as phytoremediators, use of woody trees would encourage a long-term metal sequestration which would reduce the cost of biomass disposal. Also, use of non-edible plants would prevent the plants from entering the food chain. For a holistic biochar-phytoremediation technique, incineration and pyrolysis can effectively dispose contaminated biomass. From the economical viewpoint, the environment cost-benefit analysis should be considered before considering the feasibility of a technology.HighlightsMass scale in-situ biochar production and economics are keys issues.Biochar assisted phytoremediation for HM contaminated mine spoils.Long term studies using woody biomass needs attention.Disposal of contaminated biomass by pyrolysis method.

Isolation and Characterization in a Soil Conditioned With Foaming Agents of a Bacterial Consortium Able to Degrade Sodium Lauryl Ether Sulfate.

The anionic surfactant Sodium Lauryl Ether Sulfate (SLES) is the principal component of several commercial foaming products for soil conditioning in the tunneling industry. Huge amounts of spoil material are produced during the excavation process and the presence of SLES can affect its re-use as a by-product. Anionic surfactants can be a risk for ecosystems if occurring in the environment at toxic concentrations. SLES biodegradability is a key issue if the excavated soil is to be reused. The aim of this study was to identify bacteria able to degrade SLES, so that it could potentially be used in bioaugmentation techniques. Enrichment cultures were performed using bacterial populations from spoil material collected in a tunnel construction site as the inoculum. A bacterial consortium able to grow in a few hours with SLES concentrations from 125 mg/L to 2 g/L was selected and then identified by Next Generation Sequencing analysis. Most of bacteria identified belonged to Gamma-Proteobacteria (99%) and Pseudomonas (ca 90%) was the predominant genus. The bacterial consortium was able to degrade 94% of an initial SLES concentration of 250 mg/L in 9 h. A predictive functional analysis using the PICRUSt2 software showed the presence of esterase enzymes, responsible for SLES degradation. The bacterial consortium selected could be useful for its possible seeding (bioaugmentation) on spoil material from tunneling excavation.