No abstract

No abstract

No abstract

No abstract

No abstract

A heteroscorpionate ligand, potassium hydrobis(benzoato)(salicylaldehyde)borate (KL), has been synthesized. This was converted into organotin complexes R 2 SnL 2 and R 3 SnL complexes by mixing and stirring with a methanolic solution/suspension of organotin chloride. The ligand and its complexes were characterized by elemental analyses and spectral studies (IR, 1 H NMR, 13 C NMR, ESI mass spectra and Thermo gravimetric analysis (TGA)). Antibacterial and antifungal studies of these compounds were evaluated by the disc diffusion method at variable concentration against three species of bacteria (Staphylococcus aureus, Klebsiella pneumonia and Bacillius subtillis) and two species of fungi (Asperjillius fiavus and Candida albicans). It was found that triorganotin derivatives (R 3 SnL) of the ligand were more effective as compared with diorganotin derivatives (R 2 SnL 2 ). The organotin complexes of borates were tested for their algicidal activity on the cyanobacterial strains Aulosira fertilissma, Anabaena species, Anabaena variabilis and Nostoc muscorum and showed high to moderate toxicity towards the above species. The ligand and its complexes were also tested for its pH effect on soil in vitro for a duration of more than one month and it was found that they are able to kill pests without damaging the soil quality.

No abstract

The leachate released from dumpsites can cause severe contamination of land and water. By studying seasonal variations of leachate characteristics generated from three active landfill sites of Delhi (India), it was found that seasonal variations can significantly affect the composition of leachate. Various parameters, such as conductivity, total dissolved solids (TDS), biochemical oxygen demand (BOD), chemical oxygen demand (COD), total Kjeldhal, ammoniacal nitrogen, organic nitrogen, heavy metals, chlorides and sulfates, are being released throughout the year beyond the prescribed disposal limit. It has also been seen that substantial quantities of industrial and other hazardous waste materials are also being dumped into the landfills. One can also find significant amounts (much above the permissible disposable limits) of substances such as TDS, COD, BOD, chloride, cyanide, and as in the inland surface waters. Already, the existing landfills are chocked much beyond their receiving capacity. Hence, if more waste matter is dumped in such places, it would only lead to releasing more hazardous leachate substances for a longer duration. This study will provide an in-depth analysis of leachate quality in three active landfill sites in the city of Delhi. This would enable the concerned authorities to install more effective seasonal-specific leachate management facilities at such landfills.