Vermicomposting of tender coconut waste and its potential application for the detoxification of herbicides in soil

Abstract

In modern-day agriculture, herbicides are extensively used to kill weeds. The herbicide residue has a hazardous effect on both the soil as well as living beings and enters the food chain causing bio toxicity, hence it is important to remediate the contaminated soil containing herbicides (2,4-D). The work, aimed at remediating herbicide by vermicomposting using tender coconut fibers. Coconuts are widely used in temples as a part of rituals. There is a lot of coconut waste generated, which is always a threat. To the spread of the epidemic in the surrounding area, as it is rich in nutrients. The compost was carried out for different ratios of 1:1, 1:2, 2:1, 1:3, and 3:1 volumetric mix (cow dung: tender coconut fibers). The parameters like pH, Nitrogen, Moisture, Temperature, Total Organic Carbon, and C/N have been analyzed. The result shows 1:1, 2:1, and 3:1 was stable and mature compost. Also, data reviles that in the thermophilic phase due to high temperatures of around 500C lignin and lignocellulose converted to humus. newlineThen vermiremediation was carried out in 3 trails A1 control soil, A2 un-contaminated soil, A3 contaminated soil. The ph, nitrogen, organic matter, micronutrients (P, K, Ca, Mg), Magnesium, Copper, zinc (heavy metals ), boron, and 2,4-D (herbicides) were analyzed. The results show that there was a 4% increase in micronutrient content. The herbicide (2,4-D) content was reduced by 40% which indicates that vemiremediation was carried out successfully and confirmed with HPLC analysis. But for successful remediation, we need to maintain optimum moisture, temperature, and sufficient time should be given for effective remediation. There was mortality of Earthworms in contaminated soil A3. To understand this toxicity analysis was carried out. The trial run was carried out on varying lethal concentrations (LC) of 2,4-D. The trail runs were done on un-contaminated soil, LC10 (200ppm), LC30 (400ppm,) LC50 (500ppm), and LC90 (1000ppm). The results obtained show high mortality rate in LC 50 and LC 90. The cocoo