Mechanochemical conversion of brominated POPs into useful oxybromides: a greener approach

Abstract

Brominated organic pollutants are considered of great concern for their adverse effect on human health and the environment, so an increasing number of such compounds are being classified as persistent organic pollutants (POPs). Mechanochemical destruction is a promising technology for POPs safe disposal because it can achieve their complete carbonization by solvent-free high energy ball milling at room temperature. However, a large amount of co-milling reagent usually is necessary, so a considerable volume of residue is produced. In the present study a different approach to POPs mechanochemical destruction is proposed. Employing stoichiometric quantities of Bi2O3 or La2O3 as co-milling reagent, brominated POPs are selectively and completely converted into their corresponding oxybromides (i.e. BiOBr and LaOBr), which possess very peculiar properties and can be used for some actual and many more potential applications. In this way, bromine is beneficially reused in the final product, while POPs carbon skeleton is safely destroyed to amorphous carbon. Moreover, mechanochemical destruction is employed in a greener and more sustainable manner.

Mechanochemical mineralization of “very persistent” fluorocarbon surfactants ‒ 6:2 fluorotelomer sulfonate (6:2FTS) as an example

“…It is realized at environmental temperature by high energy milling of the organic pollutants with a co-milling reagent that boosts the reaction rate. Thanks to its solvent-freeness, simple plant design, and easiness of reaction control, MC destruction is considered a green technology 29 , 30 . A number of chlorinated and brominated organic pollutants were efficaciously mineralized into halides and amorphous carbon by high energy milling.…”

Kalsiyum oksit varlığında teknik hegzaklorosiklohegzan’nın mekanokimyasal parçalanması

“…Serbest kalan elektron organik yapıdaki karbon iskeletinin bozulmasına sebep olur. Özellikle oksijen anyonu karbondan elektron alarak sekizli oktetini tamamlar ve CO 2 , su ve amorf/grafitik karbon oluşmasına sebep olur [16]. t-HCH'nin parçalanma mekanizması C-Cl bağlarının ayrışmasına bağlı olup, elektron transferlerinin ardından t-HCH moloküllerinin parçalanması beklenmektedir.…”

“…Amaç inorganik materyal üretmektedir. Öğütme sırasında organik bileşikler tamamıyla parçalanırken reaksiyon sonrasında ortamda reaksiyona girmemiş reaktif madde, metal halid (metalhalojen bileşiği) ve karbonlu materyaller (ve karbon oksitler) kalmaktadır [16].…”

“…Bu noktada mekanokimyasal prosesler t-HCH gibi organik kirleticilerin bertarafında hızla gelişen bir araştırma alanı olarak ortaya çıkmıştır. Geçtiğimiz 20 yıldan beri gezegen hareketli yüksek enerjili bilyalı sistemler kalıcı organik kirleticilerde (KOK) dahil olmak üzere birçok kirleticinin parçalanması için kullanılmaktadır [16]. Aynı zamanda yüksek mil enerjisinin kullanımı neticesinde geleneksel metotlarla üretilemeyecek birçok materyalde üretilebilmektedir.…”

Synthesis and Regeneration of A MXene-Based Pollutant Adsorbent by Mechanochemical Methods

“…High energy ball milling is largely employed to provide such energy to solids through countless hits of milling balls occurring into high speed moving jars [15]. Since solvents are not required (at most, only small amounts), MC synthesis is considered a green way to prepare materials [16,17]. More interestingly, some adsorbents that were used to capture organic pollutants can be also regenerated by simple high energy ball milling [7].…”