INTRODUCTION:

Wheat (Triticum aestivum L) is the most extensively grown cereal crop in the world, covering about 237 million hectares annually, accounting for a total of 420 million tonnes¹, and for at least one-fifth of man’s calorie intake². Wheat is an annual grass growing to between ½ to 1 ¼ meters in height, with a long stalk that terminates in a tightly formed cluster of plump kernels enclosed by a beard of bristly spikes. Abundant use of chemical fertilizer and pesticides affect the physico-chemical properties of soil as well as the environment^3,4 and enhance the level of heavy metals such as Cd, Pb and As in agricultural fields^5,⁶.

Heavy metals comes to environment by erosion of rocks, volcanic activities, forest fire but artificially by many industries, paper mills, vehicles and human activites^7,8.

The rapid industrialization has also increased the solid waste management problems⁹. Many anthropogenic activities increase the toxic heavy metals into the environment^10,¹¹. Animal and municipal solid wastes contain toxic substances, compostable organic matter and heavy metals¹². The different types of municipal solid wastes caused environmental hazards and various ill effects on human health, if their proper management and practices are not available^13,14. Safe values for lead and cadmium in fruit and vegetables recommended by WHO/FAO are 0.3, and 0.2 mg/kg, respectively^15,16. Soils give a suitable natural environment for biodegradation of wastes. The heavy metals such as Cr, Fe, Ni, Pb, Zn and Cu are present in considerable amount in the soil of Jharia coal field of Jharkhand^17,18. Heavy metal contents in soil, water, fodder and its consequences in livestock where it accumulate in their vital organs including liver, kidney causing adverse effects on their health^19,20. Bioaccumulation of heavy metal toxicity from the food chain is one of the major environmental health problems and potentially dangerous and it can cause hazardous effect on livestock and human health^21,22. The lead (Pb) is responsible to damage liver, kidney and brain cells which cause ultimately death, miscarriage in pregnant women whereas cadmium (Cd) also causes acute and chronic toxicity symptom in human²³.

Cd, Cr and Ni encountered in industries dealing with pigments, metal plating, some plastic and batteries²⁴. Earthworms are major macro soil fauna component in soil functioning and play an important role in chemical element transformation and accumulation of heavy metals from soil and disease risk of heavy metals to the to human and livestocks²⁵. Accumulation of the pesticides and heavy metals was reported in the tissues of earthworm Eisenia fetida^26-27. Vermicompost decreased toxic metals and is rich source of beneficial microorganisms, higher level of plant available nutrients and therefore may enhance the soil fertility^28-29, and also is a tool for management of waste and heavy metal contaminations³⁰.

In present investigation the concentration of different heavy metals, namely, cobalt (Co), chromium (Cr), lead (Pb) were determined in vermibeds prepared from different combinations of animal (buffalo, cow, goat, horse and sheep) dungs in initial feed mixture of vermibeds and in final vermicompost during vermicomposting by earthworm Eisenia fetida as well as in earthworm body and wheat grains

MATERIALS AND METHODS:

Collection of Animal Wastes:

The animal dungs were collected from different places of Gorakhpur district of Uttar Pradesh such as cow and buffalo dung from dairy sheep and goat dung from goatry and horse dung from horse barrack.

Collection of Earthworms:

Earthworms Eisenia fetida, an epigeic species were cultured in Vermi biotechnology Laboratories, Department of Zoology, D.D.U. Gorakhpur University, Gorakhpur. The collected earthworms were reared in laboratory condition, at temperature ranging 20⁰C to 30 ⁰C with proper and aeration. The moisture was maintained up to 50-70% RH for proper growth and survival of the earthworms.

Method of Vermicomposting:

The vermicomposting was conducted on cemented earth surface. Different combinations of animal dung with municipal solid wastes as well as with kitchen waste viz., in 1:1, 1:2 and 1:3 ratio was performed. The size of each vermibed was 3m × 1m × 9cm. After formation of vermibed, it was moist and inoculated with 2kg of cultured Eisenia fetida in each bed. The beds were covered with jute pockets and moisten daily up to 40 to 50 days to maintain the proper moisture content. The mixture of bed was manually turned up for 3 weeks at one week interval. After 50 to 60 days, granular tea like vermicompost appears on the upper surface of the beds.

Experimental Setup for the Crop Cultivation:

Six beds (1×1m) for each crop were selected in the laboratory field of deportment of Zoology, D. D. U. Gorakhpur, University, Gorakhpur. One kilogram of vermicompost of different animal dungs was mixed gently in each bed soil. These after 50 individual of adult earthworm (Eisenia fetida) were inoculated in the each bed. General agro-practices were applied in the field except using any pesticides and fertilizers. Triticum aestivum (PBW 154) are raised due to their economic importance as staple food for human health.

Analysis of heavy metals:

In initial feed mixture, vermicompost, soil and crop grains:

The heavy metal content of the initial feed mixture, vermicompost, soil (before inoculation of earthworm and after harvesting of the crops) as well as Triticum aestivum (PBW 154) seeds were measured. About 1g of initial feed mixture, vermicompost and soil (before inoculation and after harvesting of the crops) was obtained to prepare the required samples. These samples were subjected to digestion by adding excess of nitric acid (1:1) and were placed on hot plate and heated for 4 hours at 90 to 100⁰C and care was taken to ensure that sample did not dry out during the digestion. After digestion, each sample was filtered through Whatman No 41 filter paper and poured into 100ml flask, then injected into flame atomic absorption for determination of the heavy metal concentration.

In earthworm body:

Earthworms were individually dried, ground and burn to ash at high temperature. Thereafter, the ash was placed in a test tube of 15ml and 55% nitric acid was added in it. This solution was left for 12 hours at the room temperature. After that the sample was heated at temperature of 40 to 60^oC for 2 hours and solution was cooled at room temperature. The sample was again reheated at 90- 95^oC and then 1ml of 70% perchloric acid was added. The sample was allowed to cool before adding 5ml of distilled water. Samples were again reheated up to 130^oC until white fumes come out. The sample was cooled finally before being micro filtered. The solution was filtered through Whatman No 41 filter paper in a glass vials to 100ml flasks and was subjected to flame atomic absorption.

Statistical Analysis:

All the data are expressed as mean±SD of 6 replicates. Students ‘t’ test was applied to determine the significant (P<0.05) between initial feed mixture of different animal dung with municipal solid waste and kitchen waste and vermicompost, earthworm (E. fetida) body during inoculation and after vermicompost, before and after harvesting of wheat (Triticum aestivum) crop as well as earthworm body.

RESULTS AND DISCUSSION:

The data were displayed in Tables 1-2. the earthworm, Eisenia fetida is effective in lowering down the heavy metals in different animal dungs, tested during vermicomposting (60 days). Maximum cobalt 70.85%, Cromium 64.11% and lead 72.29% significant decrease was observed in buffalo dung in final vermicompost with respect to initial feed mixture whereas, the significant increase of cobalt 44.08% in buffalo dung, Cromium 9.59% in cow dung and Lead 30.90% in vermicompost of buffalo dung (Table1-2).

Table 1: Concentration of Cobalt, Chromium and Lead (mg/Kg) in different combinations of animal dung in initial feed mixture and final vermicompost by earthworm Eisenia fetida.

Particulars	Heavy Metals (mg/Kg)
	Co			Cr			Pb
	IFM	FV	% Decrease	IFM	FV	% Decrease	IFM	FV	% Decrease
Buffalo Dung (BD)	1.719± 0.002	0.501± 0.003	70.85	1.201± 0.002	0.431± 0.003	64.11	2.960± 0.002	0.820± 0.004	72.29
Cow Dung (CD)	0.879± 0.001	0.350± 0.002	60.18	1.38± 0.003	0.601± 0.004	56.44	1.151± 0.001	0.401± 0.003	65.16
Goat Dung (GD)	0.275± 0.002	0.116± 0.003	57.81	0.831± 0.001	0.415± 0.003	50.06	0.711± 0.003	0.321± 0.005	54.85
Horse Dung (HD)	0.301± 0.004	0.110± 0.001	63.45	0.820± 0.004	0.330± 0.002	59.75	0.541± 0.002	0.301± 0.002	44.36
Sheep Dung (SD)	0.307± 0.001	0.105± 0.004	65.79	0.550± 0.005	0.255± 0.003	53.63	0.710± 0.003	0.280± 0.003	60.56
IFM = initial feed mixture, FV= final vermicompost, BD = Buffalo dung, CD = Cow dung, GD = Goat dung, HD = Horse dung and SD= Sheep dung Each value is the Mean ± SD of six replicates. Significant P<0.05't' test between initial feed mixture and final vermicompost.

Table 2: Concentration of heavy metals (mg/Kg) in earthworm Eisenia fetida body after vermicomposting of different animal dung.

Particulars	Heavy metals (mg/Kg) accumulation in earthworm body from IFM during vermicomposting
	Co			Cr			Pb
	Ef BC	Ef BFV	% Increase	Ef BC	Ef BFV	% Increase	Ef BC	Ef BFV	% Increase
Buffalo Dung (BD)	1.181± 0.003	2.112± 0.002	44.08	8.101± 0.002	8.911± 0.004	9.08	3.801± 0.003	5.501± 0.003	30.90
Cow Dung (CD)	1.181± 0.003	1.418± 0.003	16.71	8.101± 0.002	8.961± 0.003	9.59	3.801± 0.003	4.601± 0.002	17.38
Goat Dung (GD)	1.181± 0.003.	1.351± 0.004	12.58	8.101± 0.002	8.401± 0.002	3.57	3.801± 0.003	4.101± 0.003	7.31
Horse Dung (HD)	1.181± 0.003	1.305± 0.002	9.50	8.101± 0.002	8.450± 0.004	4.13	3.801± 0.003	3.985± 0.002	4.61
Sheep Dung (SD)	1.181± 0.003	1.311± 0.001	9.91	8.101± 0.002	8.301± 0.003	2.40	3.801± 0.003	4.155± 0.003	8.51
IFM = initial feed mixture, BD = Buffalo dung, CD = Cow dung, GD = Goat dung, HD = Horse dung, SD = Sheep dung. EfBC = earthworm Eisenia fetida body (control), EfBFV = earthworm Eisenia fetida body in final vermicompost Significant P<0.05't' test between earthworm body (control) and earthworm body after prepared final vermicompost.

Table 3. Concentration of cobalt (mg/kg) in experimental soil, wheat grain and earthworm body before sowing and after harvesting the crop (wheat) when the soil was mixed with vermicompost of different animal dungs and inoculated with earthworm Eisenia fetida.

Particulars	Concentration of cobalt (mg/kg)
	In experimental soil			In wheat crop grains			In earthworm body
	Before sowing	After harvesting	% Change	Before Sowing	After harvesting	% Decrease	Before sowing	After harvesting	% Increase
Soil control	1.253 ± 0.002	1.266 ± 0.005	1.03	0.751± 0.005	0.413± 0.008*	45.01	-	-	-
Soil+VC of BD+Ef	1.261± 0.003*	0.863 ± 0.003*	-31.56	0.751± 0.005	0.294 ± 0.003*	60.85	4.183 ± 0.005	5.265± 0.004*	20.55
Soil+VC of CD+Ef	1.259± 0.005*	0.746 ± 0.004*	-40.75	0.751± 0.005	0.163 ± 0.003*	78.30	4.183 ± 0.005	5.278± 0.002*	20.75
Soil+VC of GD +Ef	1.268± 0.002*	0.905 ± 0.002*	-28.63	0.751± 0.005	0.197 ± 0.004*	73.77	4.183 ± 0.005	5.251± 0.005*	20.34
Soil+VC of HD+Ef	1.257± 0.005*	0.942 ± 0.002*	-25.06	0.751± 0.005	0.158 ± 0.005*	78.96	4.183 ± 0.005	5.269± 0.003*	20.61
Soil+VC of SD +Ef	1.265± 0.004*	0.859 ± 0.003*	-32.09	0.751± 0.005	0.162 ± 0.002*	78.43	4.183 ± 0.005	5.257± 0.003*	20.43
VC = vermicompost, BD = buffalo dung, CD = cow dung, GD =goat dung, HD = horse dung, SD = sheep dung, Ef = earthworm Eisenia fetida

Values are expressed as Mean ± SD (six replicates).

*Differences between mean values of concentration of heavy metals the soil, soil with different animal dungs vermicompost, earthworm body as well as before sowing and after harvesting of wheat crop grain are significant at P<0.05 (t-test).

Table 4. Concentration of chromium (mg/kg) in experimental soil, wheat grain and earthworm body before sowing and after harvesting the crop (wheat) when the soil was mixed with vermicompost of different animal dungs and inoculated with earthworm Eisenia fetida.

Particulars	Concentration of chromium (mg/kg)
	In experimental soil			In wheat crop grains			In earthworm body
	Before sowing	After harvesting	% decrease	Before Sowing	After harvesting	% change	Before sowing	After harvesting	% increase
Soil control	9.004 ± 0.003	8.685 ± 0.005	3.54	0.413 ± 0.003	0.538 ± 0.005*	23.23	-	-	-
Soil+VC of BD+Ef	9.057 ± 0.004*	6.237 ± 0.005*	30.73	0.413 ± 0.003	0.256 ± 0.002*	-38.01	47.260 ± 0.003	49.128± 0.002*	3.80
Soil+VC of CD+Ef	9.038 ± 0.003*	6.485 ± 0.002*	27.98	0.413 ± 0.003	0.946 ± 0.005*	56.34	47.260 ± 0.003	49.115± 0.005*	3.78
Soil+VC of GD +Ef	9.046 ± 0.003*	6.254 ± 0.004*	30.54	0.413 ± 0.003	0.265 ± 0.006*	-35.84	47.260 ± 0.003	48.850± 0.006*	3.25
Soil+VC of HD+Ef	9.053 ± 0.005*	6.749 ± 0.008*	25.04	0.413 ± 0.003	0.248 ± 0.003*	-39.95	47.260 ± 0.003	49.132± 0.002*	3.81
Soil+VC of SD +Ef	9.029 ± 0.003*	6.751 ± 0.002*	25.02	0.413 ± 0.003	0.072 ± 0.005*	-82.57	47.260 ± 0.003	48.963± 0.004*	3.48
VC = vermicompost, BD = buffalo dung, CD = cow dung, GD =goat dung, HD = horse dung, SD = sheep dung, Ef = earthworm Eisenia fetida

Values are expressed as Mean ± SD (six replicates).

Table 5. Concentration of lead (mg/kg) in experimental soil, wheat grain and earthworm body before sowing and after harvesting the crop (wheat) when the soil was mixed with vermicompost of different animal dungs and inoculated with earthworm Eisenia fetida.

Particulars	Concentration of lead (mg/kg)
	In experimental soil			In wheat crop grains			In earthworm body
	Before sowing	After harvesting	% decrease	Before Sowing	After harvesting	% decrease	Before sowing	After harvesting	% increase
Soil control	5.560 ± 0.003	5.391 ± 0.003	3.04	1.264 ± 0.003	0.845 ± 0.005*	33.15	-	-	-
Soil+VC of BD+Ef	5.621 ± 0.003*	4.125 ± 0.002*	26.61	1.264 ± 0.003	0.652 ± 0.004*	48.42	12.849 ± 0.003	14.553± 0.003*	11.71
Soil+VC of CD+Ef	5.615± 0.004*	3.857 ± 0.003*	31.31	1.264 ± 0.003	0.614 ± 0.003*	51.42	12.849 ± 0.003	14.611± 0.004*	12.06
Soil+VC of GD +Ef	5.629± 0.002*	4.167 ± 0.005*	25.97	1.264 ± 0.003	0.521 ± 0.003*	58.78	12.849 ± 0.003	14.526± 0.003*	11.54
Soil+VC of HD+Ef	5.633 ± 0.003*	4.216 ± 0.003*	25.16	1.264 ± 0.003	0.617 ± 0.004*	51.19	12.849 ± 0.003	14.534± 0.003*	11.59
Soil+VC of SD +Ef	5.618 ± 0.004*	4.256 ± 0.002*	24.24	1.264 ± 0.003	0.635 ± 0.003*	49.76	12.849 ± 0.003	14.529± 0.002*	11.56
VC = vermicompost, BD = buffalo dung, CD = cow dung, GD =goat dung, HD = horse dung, SD = sheep dung, Ef = earthworm Eisenia fetida

Values are expressed as Mean ± SD (six replicates).

Heavy metals accumulate in the soil of through emissions from the rapidly expanding industrial areas, mine tailings, disposal of high metal wastes, leaded gasoline and paints, land application of fertilizers, animal manures, sewage sludge, pesticides, wastewater irrigation, coal combustion residues, spillage of petrochemicals, and atmospheric deposition^31-32. Soils are the major sink for heavy metals released into the environment by aforementioned anthropogenic activities and unlike organic contaminants which are oxidized to carbon (IV) oxide by microbial action, most metals do not undergo microbial or chemical degradation^33-34. The stabilized sludge has metal levels below the limits set by the USEPA in 60 days^35-36.

The earthworm, Eisenia fetida is effective in lowering down the Co in different wastes during the vermicomposting due to the microbial activity during vermicomposting enhance the mineralization of inorganic substances and provides suitable conditions for the accumulation of heavy metals into the body of earthworm Eisenia fetida³⁷. The vermicomposting could be an appropriate technology for metal remediation from noxious urban sludges at low input basis³⁸. The buffalo dung is good feed material for earthworm during feeding mechanism the cobalt metal accumulate in earthworm body such as gizzard in higher comparably than posterior region of intestine. However, certain toxicants may be present in municipal sludge, which may threaten crop yield, long-term soil quality, and human health^39-40. Furthermore, such available forms of metals are then absorbed by the epithelial layer of gut during the transiting of wastes through it. Bioaccumulation of high concentration of metals is well documented⁴¹.

Earthworm while ingest organic waste and soil, consume heavy metals through their intestine as well as through their skin, wherefore concentrating heavy metals in their body^42-43.

The use of earthworms in MSW processing and application of vermicomposts in soil have raised concerns over the concentration of heavy metals in MSW^44-45-46.The vermicomposts, produced commercially from cattle manure, market food waste and recycled paper waste, were applied to small replicated field plots planted with tomatoes (Lycopersicon esculentum) and bell peppers (Capsicum anuum grossum) at rates of 10 tonnes/hectare to 20 tonnes/hectare in 1999 and at rates of 5 tonnes/hectare to 10 tonnes/hectare in 2000⁴⁷. High rate of Cd accumulation was typical for such plants as Cirsium arvense, Trifolium pratense, Atriplex hastata, Tussilago farfara, Capsella bursapastoris, Artemisia vulgarus and Rumex confertus. Cadmium maximum content was registered among Cirsium arvense in test plot No. 4 and amounted 3.09 mg/kg of dry mass⁴⁸.

In general, mechanical turning of solid wastes at periodic intervals is not essential during the process of vermicomposting. This is due to the movement of earthworms through the solid wastes that assists in breaking down and aerating the materials, providing ideal conditions for microbes to flourish, which in turn accelerates the conversion rate of organic matter to vermicompost^49-50.

CONCLUSION:

The inoculation of earthworm E. fetida in crop fields can decompose the different wastes and plough the soil. So we can say that the vermibiotechnology is a useful process for the management of the heavy metals from soil and different wastes thus protecting the human health and environment.

ACKNOWLEDGMENT:

Authors are thankful to Prof. Ajay Singh, Head, Department of Zoology, D.D.U. Gorakhpur University, Gorakhpur, UP; India

CONFLICT OF INTEREST:

All authors declare no conflict of interest.

REFRENCES:

1. Olabanji OG, Omeje MU, Mohammed I, Ndahi WB, Nkama I. Wheat: In Cereal Crops of Nigeria: Cereals: Principles of production and utilization. (N.U.4, Iden, F.A. Showemimo eds). 2004; 230 –249.

2. Ohiagu CE, Ahmed A, Orakwe FC, Maurya P, Ajayi O, Falaki A, Kaul N. A National Wheat Production Strategy: 1987–1996.Prepared by Cereal Research Programme ,IAR, Amadu Bello University, Zaria., 1987; 67.

3. Levi GR. Sodicity. In: M.E. Sumner eds. Hand Book of Soil Science, CRC Press Boca Raton Florida. 2000; 29-63.

4. Meena D. Organic farming: Scope and importance. Agrobios Newsletter. 2007;6 (4):14.

5. Atafar Z, Mesdaghinia A, Nauri J, Homaee M, Ahmadimoghaddam M, Mahvi AH.. Effect of fertilizer application on soil heavy metal concentration. Environ Monit Assess. 2010; 160:83-89.

6. Dao TH, Unger PW. Agronomic practices in relation to soil amendments and pesticides. In Soil Amendments and Environmental Quality. Rechcigl, J.E., Ed. Lewis Publishers Boca Raton FL. 1995; 427-470.

7. Martine S, Griswold W. Human health effect of heavy metals. Environ. Sci. Technol. Briefs for citizens. 2009; 15:1-6.

8. Pereira MG, Arruda MAZ. Vermicompost as a natural adsorbent material: characterization and potentialities for cadmium adsorption. J Braz Chem Soc. 2003; 14:39-47.

9. Reinecke AJ, Viljoen SA, Saayman RJ. The suitability of Eudrilus eugeniae, Perionyx excavatus and Eisenia fetida (Oligochaeta) for vermicomposting in southern Africa in terms of their temperature requirements. Soil Biol Biochem. 1992; 24 (12):1295-1307.

10. Kaplan O, Yildrim NC, Yildirim N, Cimen M. Toxic elements in animal products and environmental health. Asian J Anim Vet Adv. 2011; 6(3):228-232.

11. Bardos P. Composting of mechanically segregated fractions of municipal solid waste-a review. Falfield, Bristol, SITA Environmental Trust. 2004; 1-143.

12. Muthukumaravel K, Amsath A, Sukumaran M. Vermicomposting of vegetable waste using cow dung. Europ J Chem. 2008; 5:810-813.

13. Kaviraj, Sharma S. Municipal solid wastes management throw vermicomposting employing exotic and local species of earthworm. Biores Technol. 2003; 90:169-173.

14. Bhatacharya SS, Chattopadhyay GN. Transformation of nitrogen during vermicomposting of fly ash. Waste Management Resource. 2004; 22:488-491.

15. Hussain F, Khaliq A, Durrani MJ. Ethnobotanical studies of some plants of Dabargai Hills, Swat. Proceedings of First Training Workshop on Ethnobotany and its application to Conservation. National Harbariun/PASA/PARC. Islamabad Pakistan. 1995; 207-215.

16. Bhartiya DK, Singh K. Heavy metals accumulation from municipal solid wastes with different animal dung through vermicomposting by earthworm Eisenia fetida. World Appl Sci J. 2012; 17:133-139.

17. Nikhil K. Heavy metals in medicinal plants of Jharia coal field area, India. Pollut Res. 2006; 25:1-7.

18. Li-wenfan Z, Ping L, Zhou M, Ping YW. Influences of heavy metals pollution of the environment on the health of sheep. Chinese J Vet Sci Tech. 1995; 25:15-17.

19. Rajaganapathy V, Xavier F, Sreekumar D, Mandal PK. Heavy metal contamination in soil, water and fodder and their presence in livestock and product: a review. J Env Sci Tech. 2011; 4(3):234-249.

20. Kotwal SK, Sharma RK, Srivastava AK. Industrial pollutants and animal health – a review. Indian J Anim Sci. 2005; 75:713-722.

21. Aschner M. Neurotoxic machanism of fish-bone methylmetry. Environ Toxicol Phamacol. 2002;12:101-102.

22. Aycicek M, Kaplan O, Yaman M. Effect of cadmium on germination, seedling growth and metal contents of sunflower (Helianthus annus L.). Asian J Chem. 2008; 20:2663-2672.

23. Mueller M, Anke M. Distribution of cadmium in the food chain (soil-plant-human), of a cadmium exposed area and the health risks of the general population. Sci Total Environ. 1994; 156:151-158.

24. Roels HA, Van Asche FJ, Overstays M, De Groof M, Lauwerys RR, Lison D. Reversibility of microproteinuria in cadmium workers with incipient tubular dysfunction after reduction of exposure. Am J Ind Med. 1997; 31:645-652.

25. Odoh R, Agbaji EB, Kagbu JA, Thomas SA. Heavy metal speciation in agricultural farmland in some selected local government areas of Benue state, Nigeria. Arch Appl Sci Res. 2011; 3(3):560-573.

26. Garg VK, Chand S, Chhillar A, Yadav VK. Growth and reproduction of Eisenia foetida in various animal wastes during vermicomposting. Appl. Ecol. & Environ. Res., Hungary. 2005; 3(2):51-59.

27. Gupta SK, Tewari A, Srivastava R, Murthy RC, Chandra S. Potential of Eisenia foetida for sustainable and efficient vermicomposting of fly ash. Water Air Soil Pollut. 2005; 163:293-302.

28. Garg P, Gupta A, Satya S. Vermicomposting of different types of waste using Eisenia foetida: A comparative study. Biores Technol. 2006; 97:391-395.

29. Bianchina JN. Development of a flowsystem for the determination of Cd in fiel alcohol using vermicompost as bioabsorbent. Talanta. 2009; 78:333-336.

30. Jain S, Singh V. Lightning Paths in Sky Share Similarities with Channel Networks on Earth. EOS, Transactions of the American Geophysical Union 2004; 85(26): doi: 10.1029/2004EO260001. ISSN: 0096-3941.

31. Khan S, Cao Q, Zheng YM, Huang YZ, Zhu YG. Health risks of heavy metals in contaminated soils and food crops irrigated with wastewater in Beijing, China. Environ Pollution. 2008; 152:686-692.

32. Zhang MK, Liu ZY Wang H. Use of single extraction methods to predict bioavailability of heavy metals in polluted soils to rice. Communic Soil Sci and Pl Anal. 2010; 41:820-831.

33. Kirpichtchikova TA, Manceau A, Spadini L, Panfili F, Marcus MA Jacquet T. Speciation and solubility of heavy metals in contaminated soil using X-ray microfluorescence, EXAFS spectroscopy, chemical extraction, and thermodynamic modeling. Geochimica et Cosmochimica Acta. 2006; 70:2163-2190,

34. Adriano DC. Trace Elements in Terrestrial Environments: Biogeo-chemistry, Bioavailability and Risks of Metals, Springer, New York, NY, USA, 2^nd edition. 2003.

35. Contreras-Ramos SM, Alvarez-Bernal D, Trujillo-Tapia N, Dendooven L. Composting of tannery effluent with cow manure and wheat straw. Biores Technol. 2004; 94:223–228.

36. Brahambhatt A. Vermistabilization of Biosolids. 20 CP Project submitted for the partial fulfilment of the degree of Master in Environmental Engineering; School of Environmental Engineering, Griffith University, Brisbane, June. 2006.

37. Suthar S, Singh S. Vermicomposting of domestic waste by using two epigeic earthworms (Perionyx excavatus and Perionyx sansibaricus). Int J Environ Sci Technol. 2008; 5:99-106.

38. Jordao CP, Nascentes CC, Cecon PR, Fontes RLF, Pereira JL. Heavy metal availability in soil amended with composted urban solid wastes. Environmental Monitoring and Assessment. 2006; 112:309-326.

39. Lee J, Rounce JR, Mackay AD Grace ND. Accumulation of cadmium with time in Romney sheep grazing ryegrass-white clover pasture: Effect of chromium from pasture and soil intake. Aust J Agric Res. 1996; 47:877-894.

40. Suthar S. Vermicomposting potential of Perionyx sansibaricus (Perrier) in different waste materials. Biores Technol. 2007; 98:1231-1237.

41. Hsu MJ, Selvaraj K, Agoramoorthy G. Taiwan’s industrial heavy metal pollution threatens terrestrial biota. Environ Pollut. 2006; 143:327-334

42. Tripathi G, Bhardwaj P. Decompostion of kitchen waste amended with cow manure using an epigeic species (Eisenia fetida) and an anecic species (Lampito mauritii). Biores Technol. 2004; 92:215-218.

43. Sharma S, Pradhan K, Satya S, Vasudevan P. Potentiality of earthworms for waste management and in other uses-a review. J Amer Sci. 2005; 1(1):4-16.

44. Arancon NQ, Edwards CA, Atiyeh R, Metzger JD. Effects of vermicomposts produced from food waste on the growth and yields of greenhouse peppers. Biores Technol. 2004; 93:139-144.

45. Wang K, Qiao Y, Zhang H, Yue S, Li H, Ji X, Liu L. Bioaccumulation of heavy metals in earthworms from ﬁeld contaminated soil in a subtropical area of China. Ecotaxicol and Environ Safety. 2018;148:876-883

46. Ruiz D, Arroyave MP, Molina AM, Barros JF, Gutierrez ME, Zapata PA. Signals of climate variability/change in surface water supply of high-mountain watersheds – case study: Claro River high mountain basin, Los Nevados Natural Park, Andean Central Mountain Range, Colombia. Medellin: World Bank Group and School of Engineering. 2009; 207.

47. Arancon NQ, Edwards CA, Bierman P, Metzger JD, Lee S, Welch C. Effects of vermicomposts on growth and marketable fruits of field-grown tomatoes, peppers and strawberries. Pedobiologia. 2003; 47:731-735.

48. Tatyana TT, Ekaterina Y, Alkhutova. Peculiarities of heavy metals accumulation by the plants of meadow phytocenosis. Open J Soil Sci. 2012; 2:275-281.

49. Kwon YT, Lee CW, Yun JH. Development of vermicast from sludge and powdered oyster shell. J Clean Prod. 2009; 17:708-711.

50. Suthar S, Singh S. Vermicomposting of domestic waste by using two epigeic earthworms (Perionyx excavatus and Perionyx sansibaricus). Int J Environ Sci Technol. 2008; 5:99-106.

Received on 23.12.2019 Modified on 27.02.2020

Research J. Pharm. and Tech. 2020; 13(7): 3205-3210.

DOI: 10.5958/0974-360X.2020.00567.3