Study On Application Of Shell Waste From Marine Aquaculture

The marine aquaculture production of shellfish and shrimp is enormous in China,resulting in a large amount of shell waste due to the low utilization rate of non-edible part.This study aims to settle the resource utilization problem of the shell waste.The dye-loaded shellfish shell powder(DSP)is made from the shell waste and then filled in natural rubber(NR)to produce DSP/NR composites.The vulcanization,mechanics,color and other properities of composites with different amounts of DSP are focused.And shrimp shell powder is also prepared to study its adsorption properties,which provides the basis of its applications in water treatment and polymer materials.The main conclusions are summarized as follows:The properties of composites are characterized by vulcanization,mechanical parameters,ap-pearance photo,etc.The results indicate that DSP can improve the rate of vulcanization due to its main component of CaCO3.The best tensile strength(24.80 MPa)of vulcanizate is obtained when 20 phr DSP are added.And other mechanical properties such as stretching stress,tear strength and hardness keep increasing with the rise of DSP amount.What's more,the uniform and bright color of vulcanized rubber can be obtained due to the presence of DSP.Compared with many fillers reported in literatures,we have obtained satisfactory mechanical properties of DSP/NR composites,with excellent color performance at the same time which could be attributed to the good dispersion of DSP.Therefore,DSP has the the potential to replace or partially replace traditional fillers.The treated shrimp shell powder(TSSP)and rough shrimp shell powder(RSSP)are prepared from shrimp shell waste and their adsorption performance on Congo red is investigated.The ad-sorption experiment shows that equilibrium adsorption capacity(qe)increases with initial concen-tration and temperature increasing.And it also indicates that the higher the concentration,the more obvious the effect of temperature on adsorption capacity.However,the value of qe decreases with the increase of pH value of dye solution.The decrease is particularly significant when pH is greater than 11,and RSSP is more obviously influenced.The isothermal adsorption curves and adsorption kinetics are fitted well by Langmuir model and pseudo-second-order kinetic model respectively,with R2>0.99.Compared with other common adsorbents,both RSSP and TSSP exhibit excellent adsorption capacity,which is about three times more than the maximum adsorption amount(69.3 mg/g)of shellfish shell powder,much higher than 139 mg/g of chitin.So,shrimp shell powder has great application value in dye wastewater treatment.