A STUDY ON THE PHYSICO-CHEMICAL PROPERTIES …

1 , (1)2012:64-66 ISSN2250-357964A STUDY ON THE PHYSICO-CHEMICAL PROPERTIES AND HEAVYMETAL CONTENT IN CRUDE OIL CONTAMINATED SOIL OFDULIAJAN, ASSAM, INDIAaBudhadev Basumatary,aSabitryBordoloi,bHari Prasad Sarma&cHamendra Chandra DasaResource Management and Environment Division,Institute of Advanced STUDY in Science and Technology, Guwahati-781 035, IndiabDepartment of Environmental Science, Gauhati University, Guwahati-781 014, of Excellence for Energy Studies Oil India Limited, Guwahat-781022, redevelopment of contaminated land is becomingincreasingly necessary under sustainable-development migration from the soil to ground water presents an environmental risk that depends on the physicochemicalproperties of the contaminated soils. The crude oil contaminated soils near oil collecting stations were assessed for heavymetal content.

2 Soil samples were collected from crude oil contaminated areas over a period of six months and heavy metalcontent was analyzed and compared with standard permissible limit of world health organization (WHO). The averageheavy metal concentrations in the soil were found to be high in case of Cr, Pb, Cd, Hg, Fe, Se and As. Some ,Cu,Ni and Mn were found to be within the prescribed WHO limits. Remediation of these contaminated sites is nowbecoming necessary in order to rehabilitate the WORDS:Contaminated soil, multiple pollutants, environmentINTRODUCTIONA nthropogenic sources of hydrocarbons and heavy metalsare polluting the environment. Heavy metal pollution fromthe biosphere has accelerated rapidly since the onset of theindustrial revolution and heavy metal toxicity poses majorenvironmental problems (Gisbertet al.)

3 , 2003). Drillingand mining activities generate large amounts of wasterocks and tailings, which are deposited on the land wastes are often very unstable and become sourceof pollution of the air, soil and water. This may eventuallylead to a loss of biodiversity, amenity, and economicwealth (Bradshaw, 1993) and human health. The mainthreats to human health from heavy metals are associatedwith exposure to lead, cadmium, mercury and metals have been extensively studied and theireffects on human health regularly reviewed byinternational bodies such as the WHO (J rup 2003). Whenthe elements necessary for human beings, flora and theenvironment exceed a certain level, they may have toxiceffects.

4 There is a potential threat when thesecontaminants enter in to the food chain throughbioaccumulation. It is, therefore, very important to assessthe extent of heavy metal pollution in contaminated areas,and also to remove heavy metal from the contaminatedland (Wong, 2003) and an understanding of reactivetransport in porous media is necessary to predict the fateof pollutants in soils and aquifers (Huet al., 2007). Theaim of present STUDY is an attempt to determine the level ofchromium, zinc, lead, copper, cadmium, nickel, mercury,iron, manganese, selenium and arsenicin certain crude oilcontaminated areas of Duliajan under the district ofDibrugarh, Assam, India, to generate reliable database forsafe future use and to help in implementing remedialpolicies to improve environmental AND METHODSD uliajan (22o21 95o18 ), one of theoldest oil fields of Assam is situated in between East andWest block of upper Buridihing Reserve , refining, and transportations are going onthere.

5 Varieties of flora and fauna grow there balancingthe toxic effects of crude oil, heavy metals and othercomponents of nature. The area experiences climate with amean annual rainfall of 1800mm, mean relative humidityof 78% and minimum temperature of 6OC and maximumtemperature of38OC( ).Field surveys were conducted from June 2009 to June2010. Five contaminated sites were surveyed and soilsamples were collected (by random sampling technique) insterile polythene bags and carried to the laboratory. Atleast three replicates were collected from each samplingsite at depths 0-15, 15-30 and 30-45cm. Soils were airdried, grinded and sieved through a sieve (2mm meshsize). Analysis of PHYSICO-CHEMICAL characteristics weredone according toAmerican Public Health Association(APHA, 1998).

6 For the analysis of chromium, zinc, lead,copper, cadmium, nickel, mercury, iron, manganese,selenium and arsenic 1g of from each soil sample was aciddigested (4:2:1; H2SO4: HCl: HNO3) and the readingsweretaken in atomic absorption spectrometer(Thermofisher Scientific iCE 3000 series). Arsenic,selenium and mercury were analysed with VP 100 vapourPhysico-chemical PROPERTIES and heavy metal content in crude oilcontaminated soil ofDuliajan65system (Thermo Scientific). Three replicated wereanalysed from each AND DISCUSSIONThe result of PHYSICO-CHEMICAL analysis of crude oilcontaminated soil is shown in table 1. The soil was range during the course of the experiment contaminated soil usually have a highcarbon content.

7 The organic carbon estimated during theexperimental period was very high ( ) whichmight be due to contamination of crude oil. The range oftotal nitrogen was to The range of phosphoruswas to The soil showed moderate range of Na( ) and K (15-18ppm). Macronutrients such as Caand Mg were found to be between 59-68ppm and 14-16ppm respectively. It was observed that the moisturecontent of the soil was between to during theexperimental period. Water holding capacity of soil rangedfrom5 to during the STUDY conductivityof soil was 230 to 245 texture is analysis of crude oil contaminated soil during summer, monsoon and winter 0. Carbon [%wt] N [%wt] P [ppm] [ppm]17 [ppm] 1Ca [ppm]68 465 5Mg [ppm]14 216 Content (%) Holding Capacity (%) 15 ( S)245 4240 5 TextureSandy loamResults represent mean SD of three replicatesTheresult of heavy metal analysis is presented in table such as Cr, Pb, Cd, Hg, Fe, Se and As were foundbeyond the permissible limit of WHO and APHA.

8 Theseheavy metals cause potential threat to human healththrough drinking water when reach to ground water. Therange of Cr is to Exposure of too much Cr cancause serious health effects, irritations in nose and throatsand skin rashes. The range of Pbfound in soil during thecourseof experiment was to metal analysis of crude oil contaminated soil during summer, monsoon and winter season in comparisonto Maximum Permissible Limit (MPL) (WHO, APHA)ElementsMPL (ppm)Summer (ppm)Monsoon (ppm)Winter (ppm)Chromium (Cr ) (Zn) (Pb) (Cu) (Cd) (Ni) (Hg) (Fe) (Mn) (Se) (As) represent mean SD of three replicatesLead above the permissible level in water can cause severehealth problems among the flora and fauna in the area.

9 Therange of Cd was between to Cadmiumabove the permissible limit can potentially cause nausea,vomiting, diarrhoea, muscle cramps, salivation, sensorydisturbances, liver injury,convulsions, shock and renalfailure along with kidney, liver, bone and blood damagefrom a lifetime exposure. Hg level was andthat of Fe was between to Bioaccumulationof methyl mercury causes minamata disease. ElementalHg causes emotional changes, insomnia, neuromuscularchanges, headaches etc. At higher exposure it also causeskidney effects, respiratory failure and even iron occurs naturally in groundwater, the higherconcentration of iron has negative impact for human andanimals. Se and As were also encountered in highconcentrations.

10 The range of Se was between that of As was between to Chronic exposure of Arsenic via drinkingwater causes various types of skin lesions such , (1)2012:64-66 ISSN2250-357966melanosis, leucomelanosis and keratosis. Othermanifestations include neurological effects, obstetricproblems, high blood pressure, diabetes mellitus, diseasesof the respiratory system and of blood vessels includingcardiovascular and cancers typically involving the skin,lung, and bladder. The skin seems to be quite susceptibleto the effects of As. Arsenic-induced skin lesions seem tobe the most common and initial symptoms of elements such as Zn, Cu, Ni and Mn were foundtobe within the permissible limits of WHO and presence of organic and inorganic contaminants insoils of Duliajan sites provides a major challenge to theredevelopment of land in line with sustainabledevelopment requirements.