Assessment of pollution by the combustion residue and smoke of boron blended flash powder.

Possible environmental effects of flash powder mixture combustion containing aluminium and boron along with other ingredients like potassium nitrate and sulphur are reported. Once the firecrackers are lighted, they burst out particulate matter and harmful gases with scintillating effect. These particulate matters and the harmful gases together make the environment fogged and get deposited on all surfaces. Recent research suggests replacing aluminium with boron to implement safety during manufacturing and to enhance performance. But the effects of the combustion residue have to be checked and compared before implementation. Hence, in this work, the possible effects of the firework mixtures particularly flash powder mixtures containing aluminium are monitored and compared with the effects of boron blended flash powder mixtures. Based on the smoke settling test, plant growth test and soil test, it is concluded that up to 12.5% of boron can be added in flash powder mixture to prevent pollution of the environment. The threshold quantity of residue without affecting the soil quality for 100 % usage of boron was found as 10 g of residue in 2 kg of soil.

Sono-synthesis approach of reduced graphene oxide for ammonia vapour detection at room temperature.

In this paper, we report the sono-synthesis of reduced graphene oxide (rGO) using polyethyleneimine (PEI), and its performance for ammonia vapour detection at room temperature. Graphene oxide (GO) and reduced graphene oxide (rGO) were prepared by sonication method by using low-frequency ultrasound under ambient condition and films were deposited by Doctor Blade method. The rGO, which has vapour accessible structure showed a good sensing response with a minimum detection limit of 1 ppm and the detection range from 1 ppm to 100 ppm. The sensing response was found to be 2% at 1 ppm and 34% at 100 ppm of ammonia and the developed sensor operated at room temperature. The sensor displays a response time of 6 s and a recovery time of 45 s towards 100 ppm of ammonia vapour. The source for the highly sensitive, selective and stable detection of ammonia with negligible interference from other vapours is discussed and reported. We believe reduced graphene oxide (rGO) could potentially be used to manufacture a new generation of low-power portable ammonia sensors.