Dumping Of Residues Research Articles

ВВЕДЕНИЕ ЭКОЛОГИЧЕСКОГО НАЛОГА В РОССИИ В СРАВНЕНИИ С ЗАРУБЕЖНЫМИ СТРАНАМИ, ЕГО ДОСТОИНСТВА И НЕДОСТАТКИ

The relevance of the chosen topic lies in the importance of maintaining a stable environmental situation and its subsequent improvement in Russia. Environmental problems directly affect the quality of human life and the effectiveness of his activities. Therefore, the subject of discussion of more and more people is the ecology and the degree of pollution of the environment. Discharges of toxic production waste into the seas and oceans, oil spills by commercial ships, illegal dumping of residues from industrial activities in places not intended for this, the use of cheap non-degradable materials for packaging by manufactories – all this is only a small part of the harm that humans cause to our nature, and only that part that can be regulated at the state level.

Experimental research on the formation of mineral-rich areas in residue gold placer deposits

Underestimation of the reserves of raw material base of gold mining (namely residue dump complexes) leads to negative social and economic consequences in the regions engaged in placer gold mining. Nonetheless, their efficient development is possible only through the use of new rational technologies of preparation and deep processing of rock mass for subsequent extraction of valuable minerals. In order to create such a technology, large-scale research was made on the nature and degree of the influence that the basic factors of the technology have on the process of migration and concentration of gold particles in a residue rock mass.

Complete Reduction of Hazardous Cr(VI) in Chromium Ore Processing Residue Dump Site

Complete Reduction of Hazardous Cr(VI) in Chromium Ore Processing Residue Dump Site

English

Increasing quantities of domestic and imported waste electronic and electric equipment (WEEE) stimulates a rapid development of informal recycling activities in developing countries. This economically driven recycling, oftentimes based on open burning or acid-base treatment, followed by open dumping of the residues, does not usually fit environmental and public health requirements. For the underlying research, the hypothesis was formulated that the specific conditions of dumping of residues from informal recycling activities are enhancing the leaching of hazardous substances into the ground- or surface water. Hence, this paper aims at identifying major influencing factors that affect leaching behaviour of heavy metals from WEEE components and assess environmental impact of informal WEEE recycling and dumping practice. A set of leaching tests were carried out with a homogenized sample of printed circuit boards from personal computers. The results of the study show that the concentrations of Pb, Zn, Cd, Ni and Cu leached from the test material, is higher than the Dutch standard of heavy metals reference value in soil. In addition, under the toxicity characteristics leaching procedure (TCLP) extraction test, 6879 ± 1342 mg/kg dissolved organic carbon (DOC) was measured. It was also confirmed that the leachability of Pb and Cd exceeds the regulatory limit of TCLP. Lead was the predominant heavy metal to leach from the waste material and 5617±739 mg/kg Pb was released by the standard pH-controlled leaching test. The column leaching test results suggested that high amount concentrations of heavy metals released were washed out before a liquid to solid (L/S) ratios of 5. Similarly, from the column leaching trend 99.3% of DOC was leached in the lower L/S ratios of (upto L/S ratio of 2). The standard pH controlled test results indicated that heavy metals were highly mobile in the acidic pH ranges. Key words: Printed circuit boards (PCBs), e-waste, leaching tests, heavy metals, dissolved organic carbon (DOC).

An interdisciplinary physical–chemical approach for characterization of arsenic in a calciner residue dump in Cornwall (UK)

During the later stages of hard-rock mining in Cornwall, UK, widespread processing and refining of arsenic in purpose-built calciners resulted in severe, localized contamination of soils with arsenic. Several physical–chemical techniques were applied to characterize arsenic in a calciner residue dump: X-ray powder diffraction (XRD), sequential extraction combined with hyphenated speciation methods, and X-ray absorption spectroscopic (XAS) methods such as XANES (X-ray absorption near-edge structure) and EXAFS (extended X-ray absorption fine structure). Arsenic was predominantly present in pentavalent form, bound to amorphous or poorly-crystalline hydrous oxides of Fe (probably α-hematite). A small amount of a non-classified crystalline iron arsenate phase was found, viz. Fe 2(As(AsO 4) 3). There was also evidence for the presence of some arsenate bound to quartz (α-SiO 2). The overall results make us believe that the normally assumed relative safety, from a mobility point of view, is questionable since only a small fraction of arsenic is found in a crystalline iron arsenate form.

EXAFS and XANES study of arsenic in contaminated soil

AbstractHistorical mining, processing and refinement of arsenic in purpose built calciners in Cornwall, UK, have resulted in extremely high contamination of soils with arsenic in some localized areas. The x‐ray absorption spectroscopic methods XANES (x‐ray absorption near‐edge structure) and EXAFS (extended x‐ray absorption fine structure) were used to retrieve arsenic molecular information, i.e. oxidation state and local structure around As atoms, in the soil from a calciner's residue dump near Camborne (which contained 8.82 wt% arsenic) and identify the most abundant modes of As bonding. The results show that arsenic is predominantly in pentavalent form, tetrahedrally bound to oxygen atoms in the first coordination sphere. Fe and Al atoms are found in the next neighbour coordination shells around As. The As–Fe and As–Al distances and coordination numbers strongly suggest that arsenate in the soil is present in two forms, viz. as amorphous or poorly crystalline hydrous oxides of Fe (most likely FeAsO4) and adsorbed on aluminium (hydr)oxides or aluminosilicates such as clay. Copyright © 2005 John Wiley & Sons, Ltd.

Dynamic studies on the mobility of trace elements in soil and sediment samples influenced by dumping of residues of the flood in the Mulde River region in 2002

In the analysis of soil samples, batch sequential extraction procedures are traditionally used for the fractionation of trace elements to access their mobility and potential risk for the contamination of groundwater. In the present work a continuous-flow technique has been used that enables not only the fast and efficient leaching of trace elements but as well as time-resolved studies on the mobilization of arsenic and selected heavy metals in different forms to be made. Rotating coiled columns (RCC) earlier used mainly in countercurrent chromatography have been successfully applied to the dynamic leaching of heavy metals from soils contaminated by flooding sludge’s. The sample was retained in a PTFE rotating column as the stationary phase whereas aqueous solutions were continuously pumped through. The contents of elements were determined by on-line coupling of RCC and inductively coupled plasma atomic emission spectrometry (ICP-AES). This enables real-time data on the leaching process to be obtained. Dynamic and traditional batch procedures were compared. It has been shown that the aqueous elution under centrifugal forced conditions is much more effective for the mobilization of heavy metals. Hence, the dynamic leaching is characterized by a substantially more intensive interaction between solid and water and is besides substantially more time-saving than the conventional batch procedure. The RCC procedure was also employed for preliminary leaching studies with a simulated “acid rain”. In comparison with the water leaching, the mobilization of heavy metals and arsenic from soil samples with employment of simulated acid rain as eluent was less effective.

Remedial Action for an Industrial Open Dump – Proposed Activities and Prospectives

This paper describes a methodology used to investigate an industrial open dump for its contamination aspects and the possible time for groundwater quality recovery after the implementation of several remedial actions. After 11 years of use of the site for dumping of residues, by the combined use of modelling and geophysics, it was determined that the contamination plume was 65m wide and more than 300m long. The main pollutants are fluorides and other salts. The remedial scheme proposed is basically regrading, impermeabilising the top. As industry needs a place to dispose of its residues it was determined that the best option for the new landfill site is to continue to use the area. The residue must be pretreated to immobilise the fluorides, and the landfill will be impermeabilised at the bottom and at the top. The modelling showed that in a monitoring well 120m below the site, 3½ years after the implementation of the measures the contamination will be only 20% of the initial value, and after 6½ years the quality of the water at that point will be equal to that of the background.

Certain Sociological Aspects Associated with Plant Competition between Native and Foreign Species in a Saline Area

Plant sociology has exercised a strong influence on the science of ecology and workers are constantly on the alert for new problems which may throw additional light on the subject. A desirable field which offers such an opportunity is the study of the sociological relationships of the foreign and native species to each other in America. Among the many inviting and favorable geographic regions in the United States for such a study, New York State is quite outstanding because of the nature of its topography and soils. The soils ranging from the saline seashores to the extremely acid bogs of the Adirondack Mountains are quite heterogeneous in their physical and chemical composition and offer in certain localities desirable habitats for the growth of foreign plant invaders. This condition together with the ease with which foreign plants entered the state through foreign shipments before quarantine laws were enacted now reveals cosmopolitan plant communities well stabilized in both natural and cultural habitats. In addition to these, denuded areas are constantly occurring by the excavation of large areas for road building materials, waterways and manufactured products as well as associated fills and residue dumps. These new physiographic areas where the soils are raw and sometimes rich in certain residue salts are highly desirable for the study of certain sociological relationships of native and foreign plants as to successional behavior under unusual environmental conditions. A new physiographic area located along the southwest shore of Onondaga Lake at the terminus of the old Erie Canal, which borders the City of Syracuse, N. Y., is similar to a condition mentioned above and forms the nucleus of the present investigation. This area, approximately one-quarter of a mile wide and one mile long, is a saline residue dump or fill about 12 feet high, deposited 34 years ago by a chemical manufacturing company. The soil is a finely ground limestone which was chemically treated and is therefore rich in salts, the principal ones being calcium carbonate, calcium chloride, sodium carbonate, sodium chloride, and potassium sulfate. Salt incrustations still occur in a few small areas slightly lower than the general surface. With the exception of a few embankments used for the pipe line which discharged the residue, the general upland region is comparatively level. Along the lake shore footslopes, terraces and ravines are evident where the soil is better drained than the main upland area of the fill.