Study On Preparation And Properties Of Micro-nano Shell Powder Purifier For Fruits And Vegetables

Fruits and vegetables, which have abundant vitamin and mineral, are popular by people and closely contacted with human being’s health. However, the over standard rate of pesticide residues in agricultural products is higher, which induces that the fruits and vegetables events contaminated by heavy metal are of frequent occurence. As a new type of material with the cheap,natural and clean advantages, shell powder has attracted more and more research’s attentions. In this paper, abandoned purple mussel shells from Zhoushan Island Shengsi were used as raw materials to prepare functional micro and nano purple mussel shell powder. The functional shell powder was characterized by BET,X-RD, DSC, IR and SEM,and its preparation process was optimized.Then experiments of adsorbing the single pesticide and single heavy metal were done respectively, and then influence factors on absorb effect were explored. Finally, marine micro-nano products which can purify fruits and vegetables were prepared, and the corresponding enterprise standard was formulated. Main conclusions are as follows:(1) According to optimizing preparation process of functional purple mussel shells powder, the impact strength of purple mussel shells powder on specific surface area was T>particle size >t. The results of variance analysis and orthogonal experiment indicated that the optimum process conditions is purple mussel shells powder with 80 mesh and calcinations at 1000 ℃for 60 min.Under this condition, specific surface area of purple mussel shells powder was 7.26513 m2/g.(2) When micro and nano purple mussel shell powder was characterized by BET,X-RD, DSC, IR and SEM, we can come to a conclusion that component of purple mussel shells powder become Ca O gradually with the increase of T and t. SEM result showed that purple mussel shells powder by high temperature activation treatment prolonged with loose organization, significant increase in specific surface area, visible surface micro/nano level uniform pore size, and higher porosity. The micro structure provides good conditions for their adsorption performance.(3)The effects of purple mussel shell powder on adsorbing the two pesticides ofimidacloprid and hymexazol at the different conductions, such as initial concentrations, T and t was investigated. Results showed that adsorption of hymexazol and imidacloprid by purple mussel shell powder were affected by the aforementioned three factors, in which initial concentration impacted greatestly. Adsorption capacity of the two pesticides increased with the increase of initial concentration, the rise of T and the extension of t, and adsorption capacity of hymexazol was up to 46mg/g which is larger than imidacloprid of35mg/g, that indicated purple mussel shell powder had good absorption on the two pesticides.(4) The effects of purple mussel shell powder on adsorbing Cd2+ and Pb2+ at the different conductions, such as p H value, T and adsorbent dosage was investigated. Results showed that adsorption of Cd2+ and Pb2+ by purple mussel shell powder were both affected by the aforementioned three factors, and p H and adsorbent dosage played a more important role. Adsorption capacity of the two heavy metal ions also increased gradually with the increase of solution p H, the rise of T and the increase of purple mussel shells powder dosage, and adsorption capacity of Pb2+was up to 5.3 mg/g which was bigger than Cd2+of4.1 mg/g. Results showed that purple mussel shell powder had excellent adsorption properties on the two kinds of heavy metal ions.