Purification of waste water from heavy metals by using ceramic membranes and natural polyelectrolytes

The method of complex formation and ultrafiltration in the selective extraction process of the heavy metals from water solutions has the well-known value. In this article the ability of using the natural complex-formers (humate, lignosulfonate) was shown. Lignosulfants may be found in the sulfur alkaline solutions, that forms as a by-product in the cellulose production. Humates and lignosulfonates have the similar structure of the elementary link and contain acid and phenol groups that are able to take part in the ion-exchange reactions with polyvalency metals (Me). The tubular ceramic membranes (membrane diameter - 8×1 mm, pore diameter - 0.1÷0.3 mkm) was used in the experiments. These membranes are being produced in Mendeleev University of Chemical Technology, Moscow on the industrial level. The purification of the water solution and waste water from ions Ca2+, Sr2+, Cu2+, Ni2+, Ca2+, Ca3+) and nuclear plants waste water. It has been established that the optimal correlation between metal and complex-former (C-f) is: Me:C-f = 25÷40. This result can be explained by the structure and reactivity of the elementary link of these natural electrolytes and by the mass of the ion. With increasing of the mass of the ion the correlation Me:C-f is decreased.; The method of complex formation and ultrafiltration in the selective extraction process of the heavy metals from water solutions has the well-known value. In this article the ability of using the natural complex-formers (humate, lignosulfonate) was shown. Lignosulfants may be found in the sulfur alkaline solutions, that forms as a by-prodcut in the cellulose production. Humates and lignosulfonates have the similar structure of the elementary link and contain acid and phenol groups that are able to take part in the ion-exchange reactions with polivalency metals (Me). The tubular ceramic membranes (membrane diameter - 8×1 mm, pore diameter - 0.1÷0.3 mkm) was used in the experiments. These mebranes are beng produced in Mendeleev Univtery of Chemical Technology, Mosciow on the industrial level. The purification of the water solution and waste water from ions Ca2+, Sr2+, Cu2+, Ni2+, Ca2+, CA3+) and nuclear plants waste water. It has been established that the optimal correlation between metal and complex-former (C-f) is: Me:C-f=25÷40. This result can be explained by the structure and reactivity of the elementary link of these natural electrolytes and by the mass of the ion. With increasing of the mass of the ion the correlation Me:C-f is decreased. The results of the purification of the water from the heavy metals is shown in Table 1.