Yeraltı Suyu ve Toprak Kirliliğine Neden Olan Başlıca Kirleticiler

1. Yeraltı Suyu ve Toprak Kirliliğine Neden Olan Başlıca Kirleticiler

3. CONTAMINANTS • Nonhalogenated volatile organic compounds (VOCs). • Halogenated volatile organic compounds. • Nonhalogenated semivolatile organic compounds (SVOCs). • Halogenated semivolatile organic compounds • Fuels. • Inorganics. • Radionuclides. • Explosives.

4. Yakma çukurları, Kimyasal üretim tesisleri veya bertaraf alanları, Kirlenmişdeniz çökelleri, Bertaraf kuyular ve liç alanları, depolama ve mezar çukurları, Elektro / metal kaplama atölyeleri, Yangınla mücadele eğitim alanları, Hangarlar / uçak bakım alanları, Toplama kanalizasyon hatlarından, depolama tanklarından, radyoaktif / karışık atık bertaraf alanlarından sızıntılar Oksidasyon havuzları / lagünler, boya sıyırma ve spreyleme alanları, Hestisit / herbisit karıştırma-hazırlama alanları, Solvent yağ giderme alanları, Yüzey barajları, Araç bakım istasyonları. Organik madde kirlenmelerininin bulunduğu alanlar;

5. Bazı halojenlenmemiş uçucu organik maddeler

6. Insoluble organic contaminants may be present as NAPLs. Dense NAPLs (DNAPLs) have a specific gravity greater than unity and will tend to sink to the bottom of surface waters and ground water aquifers. Light NAPLs (LNAPLs) will float on top of surface water and ground water. In addition, DNAPLs and LNAPLs may adhere to the soil through the capillary fringe and may be found on top of water in temporary or perched aquifers in the vadose zone. Properties and Behavior of Nonhalogenated VOCs

7. Bazı halojenlenmiş uçucu organik maddeler

8. Generally, halogenated compounds are less amenable to bioremediate than nonhalogenated compounds. In addition, the more halogenated the compound (i.e., the more halogens attached to it), the more resistant it is to biodegradation. Incineration of halogenated compounds requires specific off-gas and scrubber water treatment for the halogen, in addition to the normal controls that are implemented for nonhalogenated compounds. Properties and Behavior of Halogenated VOCs

9. HALOGENATED SEMIVOLATILE ORGANIC COMPOUNDS (SVOCs)

10. HALOGENATED SEMIVOLATILE ORGANIC COMPOUNDS (SVOCs) • Pesticides:

11. PAHs: PAHs are generally biodegradable in soil systems. Lower molecular weight PAHs are transformed much more quickly than higher molecular weight PAHs. The less degradable, higher molecular weight compounds have been classified as carcinogenic PAHs (cPAHs). Therefore, the least degradable fraction of PAH contaminants in soils is generally subject to the most stringent cleanup standards. Lower molecular weight PAH components are more water soluble than higher molecular weight PAHs. Readily mobilized compounds, such as naphthalene, phenanthrene, and anthracene, are slightly water-soluble. Properties and Behavior of Nonhalogenated SVOCs

12. PAHs: Persistent PAHs, such as chrysene and benzo(a)pyrene, present even lower water solubilities. Pyrene and fluoranthene are exceptions because these compounds are more soluble than anthracene, but are not appreciably metabolized by soil microorganisms. PAHs may undergo significant interactions with soil organic matter. Intermediate PAH degradation products (metabolites) in soil treatment systems may also display toxicity. Complete mineralization of PAHs is slow; intermediates may remain for substantial periods of time. Properties and Behavior of Nonhalogenated SVOCs

13. Pesticides: Pesticides include insecticides, fungicides, herbicides, acaricides, nematodicides, and rodenticides. Conventional methods of classifying pesticides base their categorization on the applicability of a substance or product to the type of pest control desired. Properties and Behavior of Nonhalogenated SVOCs

14. PCBs: PCBs encompass a class of chlorinated compounds that includes up to 209 variations or congeners with different physical and chemical characteristics. PCBs were commonly used as mixtures called aroclors. The most common aroclors are Aroclor-1254, Aroclor-1260, and Aroclor-1242. PCBs alone are not usually very mobile in subsurface soils or water; they are typically found in oils associated with electrical transformers or gas pipelines or sorbed to soil particles, which may transport the PCBs by wind or water erosion. Properties and Behavior of HalogenatedSVOCs

15. Pentachlorophenol (PCP): PCP is a contaminant found at many wood-preserving sites. PCP does not decompose when heated to its boiling point for extended periods of time. Pure PCP is chemically rather inert. The chlorinated ring structure tends to increase stability, but the polar hydroxyl group facilitates biological degradation. All monovalent alkali metal salts of PCP are very soluble in water. The protonated (phenolic) form is less soluble, but this degree of solubility is still significant from an environmental standpoint. PCP can also volatilize from soils. It is denser than water, but the commonly used solution contains PCP and petroleum solvents in a mixture less dense than water. Therefore, technical grade PCP floats on the top of ground water as a LNAPL. Properties and Behavior of HalogenatedSVOCs

16. Sites where fuel contaminants may be found include aircraft areas, burn pits, chemical disposal areas, contaminated marine sediments, disposal wells and leach fields, firefighting training areas, hangars/aircraft maintenance areas, landfills and burial pits, leaking storage tanks, solvent degreasing areas, surface impoundments, and vehicle maintenance areas. FUELS

17. FUELS

20. Sites where inorganic contaminants may be found include artillery and small arms impact areas, radioactive and mixed waste disposal areas, battery disposal area, burn pits, chemical disposal areas, contaminated marine sediments, disposal wells and leach fields, electroplating/metal finishing shops, landfills and burial pits, leaking collection and system sanitary lines, leaking storage tanks, oxidation ponds/lagoons, paint stripping and spray booth areas, sand blasting areas, surface impoundments, and vehicle maintenance areas. INORGANICS

21. METALS

22. Other inorganic contaminants

23. Arsenic - arsenate, As(V) ; arsenite, As(III). Both are toxic; however, arsenite is the more toxic form and arsenate is the most common form. Arsenate is fixed to soil. Iron (Fe), aluminum (Al), and calcium (Ca) forms insoluble complexes with arsenate. The presence of iron in soil is most effective in controlling arsenate's mobility. Arsenite compounds are 4 to 10 times more soluble than arsenate compounds. The adsorption of arsenite is also strongly pH-dependent. Arsenic

24. The most common ores are the sulfate (barite) and the carbonate (witherite). All barium compounds that are water or acid soluble are poisonous. Barium is not very mobile in most soil systems. In general, sludge solutions appeared to increase the mobility of elements in a soil. Barium

25. Cadmium oxide and sulfide are relatively insoluble while the chloride and sulfate salts are soluble. The adsorption of cadmium onto soils and silicon or aluminum oxides is strongly pH-dependent, increasing as conditions become more alkaline. Cadmium absorbed to mineral surfaces (e.g., clay) or organic materials would be more easily bioaccumulated or released in the dissolved state when sediments are disturbed, such as during flooding. Cadmium

26. Chromium: trivalent Cr(III),hexavalent Cr(VI), (Cr2O7)-2 and (CrO4)-2. hexavalent chromium as a chromate ion (CrO4)-2 predominates above a pH of 6; dichromate ion (Cr2O7)-2 predominates below a pH of 6. Cr(VI) associates only with soil surfaces at positively charged exchange sites. This association decreases with increasing soil pH. Iron and aluminum oxide surfaces adsorb the chromate ion at an acidic or neutral pH. Chromium (III) is the stable form of chromium in soil. Cr(III) hydroxy compounds precipitate at pH 4.5 and complete precipitation of the hydroxy species occurs at pH 5.5. most Cr(VI) in soil is reduced to Cr(III). Soil organic matter and Fe(II) minerals donate the electrons in this reaction. The rate of reaction increases with decreasing soil pH. Chromium:

27. Soil retains copper (Cu) through exchange and specific adsorption. Copper adsorbs to most soil constituents more strongly than any other toxic metal, except lead (Pb). Copper, however, has a high affinity to soluble organic ligands; the formation of these complexes may greatly increase its mobility in soil. Copper has high toxicity to aquatic organisms. Copper

28. Lead O, +2(II), and +4(IV). Lead tends to accumulate in the soil surface, Insoluble lead sulfide is typically immobile in soil as long as reducing conditions are maintained. Lead can also be biomethylated, forming tetramethyl and tetraethyl lead. These compounds may enter the atmosphere by volatilization. The capacity of soil to adsorb lead increases with pH, cation exchange capacity, organic carbon content, soil/water Eh (redox potential), and phosphate levels. Lead

29. Mercury is extremely toxic and very mobile in the environment. In soils and surface waters, volatile forms (e.g., metallic mercury and dimethylmercury) evaporate to the atmosphere, whereas solid forms partition to particulates. In soils and sediments, sorption is one of the most important controlling pathways for removal of mercury from solution; sorption usually increases with increasing pH. Mercury is strongly sorbed to humic materials. Inorganic mercury sorbed to soils is not readily desorbed. Mercury

30. Selenium (Se). Selenium occurs in nature usually in the sulfide ores of the heavy metals.It is the most strongly enriched element in coal, being present as an organoselenium compound, a chelated species, or as an adsorbed element. The toxicity of selenium depends on whether it is in the biologically active oxidized form. Selenium volatilizes from soils when converted to volatile selenium compounds (e.g., dimethyl selenide) by microorganisms. Selenium

31. Silver (Ag) occurs naturally and in ores such as argentite (Ag2S) and horn silver (AgCl). While silver itself is not considered to be toxic, most of its salts are poisonous due to the anions present. Silver compounds can be absorbed in the circulatory system and reduced silver deposited in the various tissues of the body. Silver

32. Clay carbonates, or hydrous oxides, readily adsorb zinc (Zn). Rainfall removes zinc from soil because the zinc compounds are highly soluble. As with all cationic metals, zinc adsorption increases with pH. Zinc hydrolyzes at a pH >7.7. These hydrolyzed species strongly adsorb to soil surfaces. Zinc forms complexes with inorganic and organic ligands, which will affect its adsorption reactions with the soil surface. Zinc

36. Sites where radionuclide contaminants may be found are mainly radioactive and mixed waste disposal areas RADIONUCLIDES

37. Nonvolatile and less soluble in water than some other contaminants Unlike organic contaminants (and similar to metals), radionuclides cannot be destroyed or degraded Remediation technologies applicable to radionuclides involve separation, concentration/volume reduction, and/or immobilization Properties and Behavior of Radionuclides

39. Sites where explosive contaminants may be found include artillery/impact areas, contaminated marine sediments, disposal wells, leach fields, landfills, burial pits, and TNT washout lagoons. EXPLOSIVES

40. EXPLOSIVE CONTAMINANT