Biosorption-membrane reactor with flat filtering elements: the calculation method

Summary

The results of studying the Don River water purification with the use of biosorption-membrane method in a biosorption-membrane reactor with flat-frame filtering elements are presented. An experimental plant with a capacity of less than 2.7 m³/day with addition of powdered activated carbon was constructed at the Novocherkassk water treatment facilities. The specific flow through the membrane was less than 17.6 l/(m²·h). The experimental results showed the high efficiency of natural water purification in a biosorption-membrane reactor that provided for meeting the requirements of Sanitary Rules and Regulations (SanPiN). The efficiency of COD reduction averaged to 41.2%, color – 57.3%, permanganate value – 33.3%. During the entire experiment no suspended solids were found in permeate. The obtained data were used as a basis for calculating the specific rate of organics oxidation estimated by COD and permanganate value. The maximum values of V_max oxidation rate and K_m Michaelis constant were determined by graphical method of double reciprocal. The permanganate value dependence of the specific organics oxidation rate and COD from temperature was obtained. Temperature constant of Van Hoff’s equation was determined by COD and permanganate value to calculate the specific rate of organic pollutants oxidation during winter (10–11 °С) and summer seasons (20–22 °С). The method of calculating a biosorption-membrane reactor is presented.

Key words

powdery activated carbon , natural water treatment , biosorption membrane reactor , specific oxidation rate , biosorption , membrane filtration

Natural materials for sorption purification of chrome
and cadmium-containing leachates of solid waste landfills

Summary

The analysis of the sorption characteristics of natural materials (vermiculite, expanded clay, perlite, «Trade» zeolite) during the purification of cadmium and chromium-containing leachate with a high COD load was carried out. It was determined that zeolite had the maximum sorption capacity for Cd and Cr and the lowest biological fouling. When using vermiculite and expanded clay or mixtures on their basis, one can expect an increase in the sorption capacity for Cd and Cr during microbial fouling that inevitably occurs during contacting with water polluted with organic compounds and nutrients. In this case biofouling can increase the immobilization properties of materials for redox-dependent metals due to the enzymatic resources of bacterial cells that use them as electron acceptors. The effect of microbial fouling changed the parameters of materials in different directions: for Cr, in most cases, downward, and for Cd, significantly upward. Moreover, chromium biological recovery by biofilms is an additional effect of immobilization. Varying the composition of the sorption material provides for selecting mixtures that are optimally suitable for the purification of leachates from solid waste landfills with high COD and nutrients load, both when used in situ and in surface systems.

Key words

zeolites , municipal solid waste landfill , biosorption , infiltrate , vermiculite , expanded clay , perlite , cadmium , chromium , biological recovery , permeable reactionary barriers