Eco-Physiological Impact Of Solid Waste Of A Chor-Alkali Industry On The Seed Biology Of A Crop Plant And Possible Reclamation Of The Waste By Phytochemicals.

The Chlor-alkali industry located on the river bank discharges its waste into the river directly / indirectly. It was observed that the solid waste contained significant amount of mercury much more than prescribed limit. The lechate and washings from the solid waste dumping site enter into the river during rainy season increasing the mercury level in the river water. This river water was used to irrigate the crop fields at down stream which contaminated the crop fields. The solid waste analysis indicated the highly toxic nature of the waste containing significant amount of mercury. The seed germination and seedling establishment decreased significantly in the solid waste exposed pots with the increase in solid waste (containing mercury) concentration, when compared to the respective control values. The pigments like total chlorophyll and total pheophytin content significantly decreased in exposed seedling leaves compared to control seedling leaves of the crop seedlings. Four plants were selected based on their economic importance. The leaf extracts were used for the experiments to find out a possible solution for reclamation of the solid waste. In the experimental pots, along with solid waste, 10ml of the plant extract was applied for consecutive 5days in each petripot. It was observed that the phytochemicals extracted from both Calotropis and Jatropha could not support reclamation rather further deterioration was observed. But in case of Azadirachta and Oscimum leaf extract 100% recovery was not observed. The observed values were much less than the control value. No significant improvement in seed germination or seedling growth was noted in solid waste exposed pots. However, we can conclude that application of both Azadirachta and Oscimum can support crop improvement. As Azadirachta leaf extract can be used as biopesticide instead of synthetic chemical application. The leaf extracts negates the impact of solid waste insignificantly but can be considered as a viable option for reclamation studies. Mercury contained in the solid waste is highly toxic and should not be released into the environment as the toxicant severely affects the environment and the crop plants.