Eco-friendly microplastic removal through physical and chemical techniques: a review

A growing number of synthetic plastics derived from fossil fuels are produced, and improper plastic waste management has caused a lot of pollution problems. There are many microplastics in the environment, and they disintegrate slowly in soil and water. The properties of microplastics (MPs) include long residence times, high stability, high fragmentation potential, and the ability to adsorb other contaminants. Invertebrates and planktonic organisms are easily able to accumulate microplastics in aquatic species. Therefore, microplastics (MPs) must be removed from the water and other media. This paper aims to review the occurrence, raw polymers and additives, and remediation methods for removing microplastics from the environment. Several methods are available for removing contaminants, including sorption, filtration and chemical treatments. Various removal methods are discussed along with their methods, efficiency and advantages

Solid-State Mechanochemical Synthesis of Kaolinite-Urea Complexes for Application as Slow Release Fertilizer

This study investigated a mechanochemical (MC) process for synthesizing a slow-release urea fertilizer by cogrinding the starting materials of (NH2)2CO and amorphous kaolinite in a planetary ball mill. The tests with kaolinite contents ranging from 25 to 75 wt. %, milling time ranging from 1 (h) to 3 (h) and mill rotational speeds from 200 to 700 rpm were performed to evaluate the incorporation of (NH2)2CO and release of nitrogen into the solution. The analyses conducted using XRD, TGA, FT-IR and KNDU (Kjeldahl Nitrogen Determination Unit) indicated that the MC process was successfully applied to incorporate (NH2)2CO into the amorphous kaolinite structure. The release of nitrogen from the system (kaolinite-(NH2)2CO) when dispersed in water for 24 h reached up to 20% at 25% wt of kaolinite. Moreover, under the milling speed conditions for the system (kaolinite–(NH2)2CO), release of nitrogen reached between 25 and 40%. These results indicated that the MC process can be developed to allow amorphous kaolinite to act as a carrier of nitrogen nutrients to be released slowly for use as fertilizer