Informatics Publishing Limited

Priyal Pandey ¹, Mahendra Kumar Verma ¹, Raj Mukhopadhyay ², Nirmal De ¹, Resham Dwivedi ³, N. C. Karmakar ³, Sumit Pandey ⁴, Rakesh Kumar Singh ⁴

Affiliations
1 Department of Soil Science and Agricultural Chemistry, IAS, BHU, Varanasi, IN
2 Department of Soil Science and Agricultural Chemistry, IARI, Delhi, IN
3 Department of Mining Engineering, IIT, BHU, Varanasi, IN
4 Department of Mycology and Plant Pathology, IAS, BHU, Varanasi, IN

Abstract

Coalfield mine overburden or abandoned mine sites is a major environmental concern. Overburden materials are nutrient-poor, loosely adhered particles of shale, stones, boulders and cobbles and are devoid of true soil character. Eco-restoration or natural transformation of overburden materials to soil for cultivation is a time taking process. In the present study, we focused on how the OB materials are different from nearby natural soil and explored the characterization of physical, chemical and biological properties of different aged overburden undergoing the process of eco-restoration. Further, we have analysed various microbial population, enzymatic activities and microbial respiration process in different aged overburdens vis-a-vis nearby soil. Microbial population was more in 16 year old overburden among different aged OB but less than nearby soil. Dehydrogenase, Urease activity showed an increasing trend with maturity age of overburden representing higher microbial population, while alkaline phosphatase activity is not following any trend. Soil microbial respiration was found to be increased with age of overburden. Carbon mineralization rate constant in all overburden lied in a narrow range (0.020-0.011) day^-1 and it did not show any significant variation as compared to native forest soil (0.03 day^-1). Mineralizable carbon was found more in native soil (7.95 mg C/kg of overburden) and 16 year old overburden (5.56 mg C/kg of overburden). Cumulative CO₂ evolved was more in native forest soil (8.67 mg C/kg), and was comparable with 16 year old overburden (5.4 mg C/ kg). Microbial population, enzymatic activity and carbon mineralization can act as an indicator for analysing changes in overburden spoil properties due to ecorestoration.

Keywords

Enzymatic Activity, Microbial Population, Overburden, CO₂ Flux.

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Vivek Kumar Kash ¹, N. C. Karmakar , d S. Krishnamoorthi ²

Affiliations
1 Department of Mining Engineering, IIT (BHU), Varanasi - 221005, Uttar Pradesh,, IN
2 Department of Chemistry, Institute of Science, Banaras Hindu University, Varanasi - 221005,

Abstract

Vehicle movement over haul road is the major source of fugitive dust emission from opencast coal mines which adversely affect the environment. Water spraying is the most common practice for controlling fugitive dust generationfrom haul road. In this work, an innovative polymer was synthesised to study its effectiveness as a dust suppressing agent. Guargum grafted polyacrylamide (GG-g-PAM) polymer was synthesised by free radical polymerisation technique using Ceric Ammonium Nitrate (CAN) initiator. Haul road dust sample was collected from a mine and characterised by sieve analysis and Energy Dispersive X-ray (EDX) analysis. An experiment was carried out at controlled environment in the oven to measure the moisture retention in a petri dish. The same experiment was repeated with only water as the dust suppressant to compare with the effectiveness of GG-g-PAM. The experiments showed that application of GG-g-PAM polymer solution instead of only water helps to increas- °C, GG-g-PAM solution has potential for suppression of haul road dust in opencast coal mines effectively

Keywords

Dust Suppression, Fugitive Dust, Haul Road, Guargum Grafted Polyacrylamide, Moisture Retention and dust emission

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Vivek Kumar Kashi ¹, N. C. Karmakar ¹, S. Krishnamoorthi ²

Affiliations
1 Department of Mining Engineering, IIT (BHU), Varanasi - 221005, Uttar Pradesh, IN
2 Department of Chemistry, Institute of Science, Banaras Hindu University, Varanasi - 221005, IN

Abstract

Vehicle movement over haul road is the major source of fugitive dust emission from opencast coal mines which adversely affect the environment. Water spraying is the most common practice for controlling fugitive dust generationfrom haul road. In this work, an innovative polymer was synthesised to study its effectiveness as a dust suppressing agent. Guargum grafted polyacrylamide (GG-g-PAM) polymer was synthesised by free radical polymerisation technique using Ceric Ammonium Nitrate (CAN) initiator. Haul road dust sample was collected from a mine and characterised by sieve analysis and Energy Dispersive X-ray (EDX) analysis. An experiment was carried out at controlled environment in the oven to measure the moisture retention efficiency of the dust applying the synthesised polymerat different temperatures 25°C, 35°C and 45°C. For this purpose, 0.1 weight percentage of GG-g-PAM was mixed with water. The solution was sprayed over 20g dust sample (below 10 mesh size) in a petri dish. The same experiment was repeated with only water as the dust suppressant to compare with the effectiveness of GG-g-PAM. The experiments showed that application of GG-g-PAM polymer solution instead of only water helps to increasing moisture retention capacity of haul road dust by 12.9% after 8 h at 25°C, 14.7% after 8 h at 35 °C, and 25.4% after 2 h at 45°C. It is also observed that application of GG-g-PAM polymer solution helped in reducing the dust generation by 36% after 8 h at 25°C, 32% at 35°C after 6 h, and 65% after 2 h at 45 °C. This shows that during scorching summer when the temperature is, in general, above 40°C, GG-g-PAM solution has potential for suppression of haul road dust in opencast coal mines effectively.

Keywords

Dust Suppression, Fugitive Dust, Haul Road, Guargum Grafted Polyacrylamide, Moisture Retention and dust emission Study

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