This chapter consists of valuing the chitosan to create bio-fertilizers as fertilizers without going through the composting process because of their richness in the nutrient base elements of plants: nitrogen and phosphorus. Physicochemical analyses of the chitosan focused on pH, dry matter, organic matter, nitrogen, phosphorus and potassium as well as IR and XRD. The samples thus prepared were monitored for 15 days. PH, temperature and conductivity were monitored daily. According to the physicochemical analyses of waste (nitrogen, phosphorus and potassium) and the nutritional needs of our selected crop (soft wheat, Arrehane variety which are 90-90-50 U/ha), several doses are then determined for the purpose of the optimal formula after their application on the crop. An application of bio-fertilizer on the potato was also undertaken. Follow-ups were carried out during this study, such as the monitoring of the vegetative growth of wheat and the mineralization of the soil via its physicochemical analyses. The results show that our bio-fertilizer is rich in nitrogen with 4.98% and phosphorus with 1.42% and mineralizes quickly on the ground while leaving the soft wheat to absorb its nutrients effectively and improving its growth properties, then giving good yields.
Part of the book: Chitin-Chitosan
FTIR spectroscopy has been widely used to quantitatively study the parameters of the chitin deacetylation. A new research on a Canadian chitin has shown that a degree of deacetylation (DD) of 90% has been reached with a base concentration of 12.5 M, a reaction time of 120 min, and a temperature of 110°C. In parallel, our study on Moroccan chitin allowed to reach 75%. A degree of deacetylation of 75% was obtained at T = 120°C and at CNaOH = 12 N in a single step for 6 hours. Another study followed by IR prepared the chitosan under pressure or under irradiation. Firstly, the compression method was used for preparing 100% deacetylated chitosan with less environmental pollution. The 100% fully deacetylated chitosan is produced in low-concentration alkali and high-pressure conditions under 0.11–0.12 MPa for 120 min. Secondly, microwave deacetylation showed that a degree of deacetylation of 95.19% was achieved after irradiating chitin at 60 meshes with 50% NaOH solution in a microwave for 10 min at 1400-W power. To find these results, the authors used different formulas to calculate DD by FTIRM, but the most used and reliable formula is that which calculates DD of chitosan by the report of absorbance of amide at 1655 cm−1 that measures the acetyl group and absorbance at 3430 cm−1 relating to the hydroxyl group.
Part of the book: Modern Spectroscopic Techniques and Applications
The objective of this chapter is to study of the heavy metal removal in real waste water. The use of the raw chitin shows itself of big potential for the treatment of the liquid discharges of the studied unity. It showed itself capable to treating heavy metal loads superior to 200 mg/l by presenting percentage removal between 90 and 97%, as in the case of Cu2+. After the study performed on the global discharge, we were interested in the local treatment that rinses out plating baths, and this is the aim to optimize the treatment process and develop a project of treatment plant, recycling in situ based on the adsorption technique on raw chitin. Examination of the results allowed us to save significant percentages of sewage treated for metals mainly copper. Raw chitin showed a high affinity toward heavy metals in rinsing water supply. According to this study, the design of a treatment facility of this type of release must include a waste water treatment by adsorption on chitin. The valuation of the raw chitin is situated in this context as an economically adsorbing material, which can be an interest at the level of the recovery of heavy metals in waste water.
The objective of this chapter was to treat metal pollution of wastewater rich in Pb2+, Cd2+, Cu2+, and Zn2+ ions by adsorption tests on the raw chitin/chitosan. Different origin namely shrimp (Ccre), crab (Ccra) and lobster (Clan). Raw shrimp chitin had a strong affinity for Pb2+ and Cd2+. The adsorption capacity of zinc on the crabs chitin is twice as great as that on the shrimp chitin. The kinetic study showed that more than 50% of these ions are adsorbed before equilibrium is reached (20 minutes). The adsorption kinetics also showed that the hardness of the shells has a negative effect on the kinetics of the adsorption process. Indeed, the adsorption of Pb2+ on the raw chitin shrimp requires only 30 minutes, while on the raw chitin lobster; the equilibrium time is 60 minutes. To ensure a sustainable treatment, sludge generated by adsorption of heavy metals was incinerated at high temperature. Incineration has led to calcite phases, which do not represent any toxicity on the environment and it can be recycled in the industry of solid materials (ceramics, cement, etc.). However, the regeneration of sludge by the acid changes the structure of the material and gives new adsorbent supports.
Part of the book: Trace Metals in the Environment