A. A. Bogush

Element composition and mineralogical characterisation of air pollution control residue from UK energy-from-waste facilities

Air pollution control (APC) residues from energy-from-waste (EfW) are alkaline (corrosive) and contain high concentrations of metals, such as zinc and lead, and soluble salts, such as chlorides and sulphates. The EPA 3050B-extractable concentrations of 66 elements, including critical elements of strategic importance for advanced electronics and energy technologies, were determined in eight APC residues from six UK EfW facilities. The concentrations of Ag (6-15 mg/kg) and In (1-13 mg/kg), as well as potential pollutants, especially Zn (0.26-0.73 wt.%), Pb (0.05-0.2 wt.%), As, Cd, Cu, Mo, Sb, Sn and Se were found to be enriched in all APC residues compared to average crustal abundances. Results from a combination of scanning electron microscopy with energy dispersive X-ray spectroscopy and also powder X-ray diffraction, thermal analysis and Fourier transform infrared spectroscopy give an exceptionally full understanding of the mineralogy of these residues, which is discussed in the context of other results in the literature. The present work has shown that the bulk of the crystalline phases present in the investigated APC residues include Ca-based phases, such as CaCl(x)OH(2-x), CaCO3, Ca(OH)2, CaSO4, and CaO, as well as soluble salts, such as NaCl and KCl. Poorly-crystalline aragonite was identified by FTIR. Sulphur appears to have complex redox speciation, presenting as both anhydrite and hannebachite in some UK EfW APC residues. Hazardous elements (Zn and Pb) were widely associated with soluble Ca- and Cl-bearing phases (e.g. CaCl(x)OH(2-x) and sylvite), as well as unburnt organic matter and aluminosilicates. Specific metal-bearing minerals were also detected in some samples: e.g., Pb present as cerussite; Zn in gahnite, zincowoodwardite and copper nickel zinc oxide; Cu in tenorite, copper nickel zinc oxide and fedotovite. Aluminium foil pieces were present and abundantly covered by fine phases, particularly in any cracks, probably in the form of Friedels salt.

Geochemical Characteristics of the Modern State of Salt Lakes in Altai Krai

A complex of analytical methods (atomic absorption spectroscopy AAS, synchrotron radiation X-ray fluorescence SR-XRF, and instrumental neutron activation analysis INAA) were used for analyses of 40 trace elements. In compliance with the conventional biogeochemical methods, enrichment factors EF were calculated for plankton relative to the average concentrations of elements in continental clay (shale) preliminarily normalized to Sc. In order to understand the concentration specifics of trace elements in living organisms inhabiting aquatic ecosystems of variable salt composition and geochemical characteristics, chemical speciation of elements was calculated for the brines of salt lakes by the WATEQ4F and Selektor-S computer programs. The enrichment of plankton in Hg in Lake Bol’shoe Yarovoe is caused not only by the chemistry of the mineralized brine (bittern), as follows from the Hg speciation in it, but also by anthropogenic contamination (Hg-bearing wastes from the Altaikhimprom chemical plants in the town of Yarovoe).

Biogenic Contribution of Minor Elements to Organic Matter of Recent Lacustrine Sapropels (Lake Kirek as Example)

An approximate biogenic contribution of minor elements to sapropel of Lake Kirek in West Siberia is estimated using the “model of direct inheritance” of their composition in plankton by OM of bottom sediments (Yudovich and Ketris, 1990). It is shown that the lifetime accumulation of P, Br, and Zn in copepod zooplankton of Lake Kirek notably affects the concentration of these elements in sapropelic mud (biogenic contribution is approximately 95–53%). The biogenic share of other elements in these sediments is substantially lower: approximately 30% for Sr and Ba; 26–16% for Ca, Pb, Cd, Cu, K, Mg, and Cr; and no more than 5% for As, Co, Fe, Ni, Ti, Y, and Mo.

Geochemical barriers to elemental migration in sulfide-rich tailings: Three case studies from Western Siberia

Abstract This study describes geochemical barriers that have developed at three different localities in sulfiderich tailings in the Kemerovo region of Western Siberia, Russia. Iron oxyhydroxides, gypsum, malachite, chalcanthite, goslarite, bianchite, gunningite and copper and zinc chlorides crystallized in the sequence specified at an evaporative barrier around glassy slag produced by the Belovo zinc processing plant. A complex cemented barrier that has developed within the old Salair sulfide tailings contains two well defined layers: an upper layer containing Fe(III) minerals and gypsum as cements in which Pb, As, Mo, Ni and Co have been deposited; and (2) a lower calcite- and gypsum-bearing layer, in which phases containing Zn, Cd and Cu have been deposited. A complex organic_mineral barrier below the Ursk sulfide tailings consists of peaty organic matter, clay minerals and iron oxyhydroxides cemented by gypsum. Elements that have leached from the tailings are present in this barrier in a variety of different forms: Ca and Mn are present as water-soluble species; Cu, Fe and Zn are present as species produced by interaction with organic matter via ion-exchange, metal humate formation and cation bridging in organic-mineral complexes; Pb and As are co-precipitated with and/or adsorbed onto iron oxyhydroxides; gold has been deposited as minute particles of native metal. The mechanisms for the formation of the different geochemical barriers are discussed.

Anomalous concentrations of zinc and copper in highmoor peat bog, southeast coast of Lake Baikal

When examining the peat deposit discovered in Vydrinaya bog, South Baikal region, the authors encountered anomalous Zn and Cu concentrations for highmoors being up to 600–500 ppm on a dry matter basis in the Early Holocene beds (360–440 cm) formed 11 000–8500 years ago. It has been demonstrated that Zn and Cu are present inside the plant cells of peat moss in the form of authigenic sulfide minerals of micron size. Apart from Zn and Cu, native Ag particles (5–7 um) have been encountered in the peat of the Vydrinaya bog at a depth of 390–410 cm; these particles formed inside the organic matter of the plasma membrane of peat moss containing Ca, Al, S, and Cu. This study suggests probable patterns of the formation of zinc sulfides, copper sulfides, and native silver in peat moss. The results obtained indicate that biogenic mineral formation plays a significant role in this system, which is a very important argument in the discussion on the ore genesis, in which physicochemical processes are normally favored, while the role of living matter is quite frequently disregarded.

Technologies for the management of MSW incineration ashes from gas cleaning: New perspectives on recovery of secondary raw materials and circular economy

Environmental policies in the European Union focus on the prevention of hazardous waste and aim to mitigate its impact on human health and ecosystems. However, progress is promoting a shift in perspective from environmental impacts to resource recovery. Municipal solid waste incineration (MSWI) has been increasing in developed countries, thus the amount of air pollution control residues (APCr) and fly ashes (FA) have followed the same upward trend. APCr from MSWI is classified as hazardous waste in the List of Waste (LoW) and as an absolute entry (19 01 07*), but FA may be classified as a mirror entry (19 0 13*/19 01 14). These properties arise mainly from their content in soluble salts, potentially toxic metals, trace organic pollutants and high pH in contact with water. Since these residues have been mostly disposed of in underground and landfills, other possibilities must be investigated to recover secondary raw materials and products. According to the literature, four additional routes of recovery have been found: detoxification (e.g. washing), product manufacturing (e.g. ceramic products and cement), practical applications (e.g. CO2 sequestration) and recovery of materials (e.g. Zn and salts). This work aims to identify the best available technologies for material recovery in order to avoid landfill solutions. Within this scope, six case studies are presented and discussed: recycling in lightweight aggregates, glass-ceramics, cement, recovery of zinc, rare metals and salts. Finally, future perspectives are provided to advance understanding of this anthropogenic waste as a source of resources, yet tied to safeguards for the environment.

Acid Rock Drainage Remediation and Element Removal Using a Peat-Humic Agent with Subsequent Thermal Treatment of the Metal–Organic Residue

A novel, alternative method for acid rock drainage (ARD) remediation and metal recovery has been developed that uses a peat-humic agent (PHA) created by mechanical, chemical, and thermobaric treatment of peat from the Krugloe deposit (Novosibirsk region, Russia). The PHA effectively neutralised moderately acidic ARD and removed potential pollutants (e.g. Fe, Al, Zn, Cu, Pb, Cd, Ni, Co, and Hg), forming metal–organic residues. The organic matter can be removed completely from the metal–organic residues by heating them at 450–500xa0°C. After this treatment, the metal concentrate residues generally contained aggregates (20–350xa0μm in size), mainly composed of metal oxides and sulphates. Thermal decomposition of the organic matter in the PHA and metal–organic residues is an exothermic process with significant calorific value (9–15xa0kJ/g).ZusammenfassungEine neuartige, alternative Methode zur Sanierung saurer Sickerwässer und zur Rückgewinnung gelöster Metalle wird vorgestellt. Torf aus der Lagerstätte Krugloe in der Region Novosibirsk (Russland) wurde unter Druck erhitzt und einer mechanischen und chemischen Behandlung unterzogen. Das resultierende Produkt (PAH) neutralisiert moderat saure Sickerwässer und bindet mögliche Schadstoffe (e.g. Fe, Al, Zn, Cu, Pb, Cd, Ni, Co und Hg). Die organische Substanz kann von den metall-organischen Rückständen durch Erhitzen auf 450–500 Grad Celsius vollständig entfernt werden. Das residuale Konzentrat enthält Aggregate einer Größe zwischen 20 bis 350xa0μm, welche überwiegend aus Metalloxyden und Sulphaten bestehen. Die thermische Zersetzung der organischen Substanz in PAH und den metall-organischen Rückständen ist exothermisch und erbringt eine Verbrennungswärme von 9–15xa0kJ/g.ResumenUn nuevo método alternativo para la remediación de drenaje ácido de roca (ARD) y para la recuperación de los metales, ha sido desarrollado usando un agente turba-húmico (PHA) creado por tratamiento mecánico, quiímico y termobárico de turba del depósito Krugloe (región Novosibirsk, Rusia). El PHA efectivamente neutralizó ARD moderamente ácida y removió los contaminantes potenciales (Fe, Al, Zn, Cu, Pb, Cd, Ni, Co y Hg), formando residuos organo-metálicos. La materia orgánica puede ser removida completamente de los residuos organo-metálicos por calentamiento a 450–500oC. Después del tratamiento, los residuos concentrados de metal generalmente contienen agregados (20–350xa0μm en tamaño), principalmente compuestos de sulfatos y óxidos del metal. La descomposición térmica de la materia orgánica en el PHA y en los residuos organo-metálicos, es un proceso exotérmico con valor calorífico significante (9–15xa0kJ/g).摘要利用一种由Krugloe矿床(新西伯利亚地区,俄罗斯)泥炭经机器、化学和温压处理制成的泥炭腐殖质(PHA)作为新型酸性矿山废水处理和金属回收处理材料。泥炭腐殖质(PHA)能有效中和中等酸性废水并去除铁、铝、锌、铜、铅、镉、镍、钴、汞等潜在污染物;进一步将有机金属残留物加热到450–500°可完全去除有机成分。最终,浓缩的金属残留物主要为粒径20–350xa0μm的金属氧化物及硫酸盐团聚物。泥炭腐殖质和有机金属残留物中有机物分解为高热值的放热过程(9–15xa0kJ/g).

Concentration of chemical elements by zooplankton of the White Sea

A technique of net sampling of zooplankton at night in the Kandalaksha and Dvinskii Bays and during the full tide in the Onezhskii Bay of the White Sea allowed us to obtain “clean” samples without considerable admixtures of terrigenous suspension. The absence of elements-indicators of the terrigenous suspension (Al, Ti, and Zr) in the EDX spectra allows concluding that the ash composition of the tested samples is defined by the constitutional elements comprising the organic matter and integument (chitin, shells) of planktonic organisms. A quantitative assessment of the accumulation of a large group of chemical elements (approximately 40) by zooplankton based on a complex of modern physical methods of analysis is presented. The values of the coefficient of the biological accumulation of the elements (Kb) calculated for the organic matter and the enrichment factors (EF) relative to the Clarke concentrations in the shale are in general determined by the mobility of the chemical elements in the aqueous solution, which is confirmed by the calculated chemical speciation of the elements in the inorganic subsystem of the surface waters of Onezhskii Bay.

Changes in composition and lead speciation due to water washing of air pollution control residue from municipal waste incineration

Changes in elemental and mineralogical composition, and lead speciation, of air pollution control residue (APCR) from municipal solid waste incineration, due to treatment by water washing, were investigated in this work and are reported in the context of a review of the literature. Water washing was shown to substantially modify the nature of APCR by: 1) removing 23% dry mass soluble salts to disagglomerate particles and significantly reduce concentrations of the associated major elements, and increase concentrations of insoluble matrix elements and potential pollutants; and 2) respeciating elements to form new phases. X-ray absorption near edge spectroscopy (XANES) showed that the 500u2009mg/kg of Pb in raw and washed APCR were comprised mainly of Pb-glass, with some PbSO4, and small amounts of PbO and PbCl2. Semi-quantitative linear combination fitting suggests that the glass in the APCR may be unstable and release Pb under the alkaline pH of water washing, to reprecipitate as PbO. Chemical analysis suggests that some Pb may be removed by washing. Scientific understanding of the composition of raw and washed APCR, and particularly the speciation of potentially toxic metals, such as Zn and Pb, can help in developing effective element recovery and residue treatment, utilization or disposal strategies.