Adsorption on activated carbon is to be used for reducing phenol concentration in wastewater from $0.04$ mol/$1$ to $0.008$ mol/$1$. The adsorption isotherm at the operating temperature can be expressed as $q=0.025C^{1/3}$ where $q$ is the phenol concentration in solid (mol/$g$ solid) and $C$ is the phenol concentration in water (mol/$1$). The minimum amount of solid (in grams) required per Iiter of wastewater (up to one decimal place) is ____________.