Preparation of dialdehyde cellulose hydrazone derivatives and evaluating their efficiency for sewage wastewater treatment

The cellulose hydrazone derivative is a novel product prepared from dialdehyde cellulose with 2-hydrazino3,5,6,7tetrahydrocyclopentanethieno[2,3-d]-pyrimidin-4(4H)-one under suitably selected conditions. It was found that the reaction of dialdehyde cellulose with the 2-hydrazino derivative decreased progressively in the series cellulose powder, viscose wood pulp and cotton linter. The principal objective of this research was to evaluate the effectiveness of dialdehyde cellulose hydrazone derivatives on sewage wastewater settling, percentage of total suspended solids (TSS), carbon oxygen demand (COD), and iron and chromium removal. About 30–50% of chlorine was removed after treatment using dialdehyde cellulose hydrazone derivatives, thus indicating their good efficiency for halogen removal. Cellulose hydrazone derivatives were recommended as good coagulants and removed Fe and Cr by 73.9% and 66.7%, respectively. Jar tests revealed that the wastewater was best treated with the addition of chemical coagulants such as FeCl3 or Al2(SO4)3 combined with cellulose hydrazone derivatives at optimum doses. The optimum conditions produced better cleaning-up and improved removal of COD and TSS up to 77% and 97%, respectively.

1. The reaction of dialdehyde cellulose with 2-hydrazino derivative decreased progressively in the series cellulose powder, viscose wood pulp and cotton linter. 2. The hydrazonyl group (-C=N-N-) was the most effective group obtained from the reaction between dialdehyde cellulose and 2-hydrazino derivatives. 3. Settling of sewage wastewater using cellulose hydrazone derivatives singly containing the hydrazonyl group -C=N-N- showed satisfactory clean-up efficiency of about 50% contaminant removal at the optimum dose. 4. Chemical additives combined with these synthetic polymers (cellulose hydrazone derivatives) improved cleaning up to 96% contaminant removal.