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Selecting a plant root nutrient delivery system is one of the key aspects of designing root modules for space plant growth chambers. This article examines a number of the nutrient delivery systems and shows the most suitable technique for providing nutrients to roots in microgravity, which to date are ion-exchange artificial soils. In addition, this article characterizes the ion composition and hydrophysical parameters of a new Russian artificial ion charged fiber substrate, BIONA-V3. The BIONA-V3 substrate is comprised of ion-exchange resin fibers. The experimental data concerning the effects of anionic and cationic components on plant biomass is presented. Preliminary experiments with BIONA-V3 showed that 1 kg of dry BIONA-V3 produces up to 2.4 kg (fresh mass) of cabbage leaf or 180 g of dry plant mass per 1 dm3 of the substrate. Therefore, the root zone volume can be as small as 120 cm3 per plant. Further optimizing the nutrient composition of the resin fibers can increase space plant growth chamber productivity.

Data on the quality of sorption afterpurification of permeates produced by nanofiltration of washing water in the ECOPSY-95 project are presented. Washing water contained essentially different detergents. Nanofiltration was performed with reeled composite membrane filters (OPMN-K). Nanofiltrated permeates were further treated with sorption techniques. The investigation confirmed the possibility get a filtrate complying with the washing water requirements. It was demonstrated that afterpurification of nanofiltered permeates by sorption improves the quality of regenerated water and also extends useful life of expandable sorption materials as compared to washing water that was not subjected to nanofiltration. Combination of nanofitration and sorption can be favorable to decrease the size of filter cartridges by 30-50%.

Wheat crop was grown in various root modules (RM) in which nutritional solution was injected through porous membrane (2-6 microns). Seeds were laid on the surface of membrane or in pearlite covering the membrane. Root modules 1 and 3 contained ceramic porous tubes 10 mm and 22 mm in diameter, respectively. RM 2 was outfitted with a porous titanium plate, RM 4--with a porous ceramic tube (Ø 10 mm) buried in pearlite, and RM 5--with a porous titanium plate under the 2.5 cm thick layer of pearlite. The area of membrane surface per one plant was equal to 3 cm2 in RM 1 and about 17 cm2 RM 2 and 3. Pearlite volume per a plant made up about 40 cm2 in RM 4.5. The object of study was Triticum aestivum L., sp. Super Dwarf. The plants grew for 49 days under the white light of luminescent lamps at water potential (WP) = -0.4, -3.0 and -5.0 kPa. WP of pearlite equal, dry mass and anticipated productivity of the crop were much higher as compared to RM without pearlite. Significant reduction of these parameters was reflective of WP drop no matter the RM type. However, it was more expressed at -5 kPa. In RM filled with pearlite the mass and productivity of crop reduced at -5.0 kPa. Design of RM essentially altered the volumetric spread of roots. Thus, root math was formed immediately on flat porous plates, commonly below the bare tubes and both on top and on the bottom of RM with pearlite. These data can help development of RM for space greenhouses.

Transport and selective characteristics of Russian nanofiltration membranes OPMN-K were investigated in order to find approaches to extend useful life of the membranes and, therefore, of the nanofiltration assembly and the washing water regenerating system at large. Hygienic cleansing agents as washing water ingredients pollute but not irreversibly impair the membranes. Flushing of membranes after regeneration of various model detergents was shown to recover the membrane permeability virtually up to original level.

Presented are results of evaluating transportability and selectivity of Russian OPMN-K membrane coil nanofilters used in a chamber experiment (project EPOKSI [correction of ECOPSI]-95) to clean washing water containing different detergents. OPMN-K nanofilters were potent to extract no less than 96 to 98% of permeate with the organic selectivity reaching 80 to 90%. The detergent-dependent dynamics of capacity and selectivity and data of analyses of producible permeates and concentrates are reported.

The analysis of the study associated with cultivating the leaf cabbage, small radish in the Russian-Bulgarian greenhouse "Svet" aboard Mir orbital space station in 1990 has demonstrated that under microgravity conditions the zeolite substrate "Balkanin" with particles dimensions of 1-3 mm placed in the root modules of the greenhouse "Svet" did not ensure the sufficient transfer of the water from moisture-saturated wicks to the periphery of the vegetation vessels what is attributable to the peculiarities of hydrophysical characteristics of the substrate used. There presented the results of experimental research on the hydrophysical and agrochemical characteristics of the ion-exchange substrates of two other types--"Biona 312" and "Biona V" prepared on the basis of the artificial ion-exchange resins: cationite--CU-2 and anionite EDE-10P. For these substrates there found the estimates of humidity correlating with the loss of gassy pores as well as there measured the specific weight of the solid phase and the volumetric weight. There presented data on the content of the nutrients as well as the results of assessing the biological productivity potential of the tested substrates in the "Svet" greenhouse root modules. The characteristics obtained are indicative of the possibility to use the mentioned substrates in space greenhouse of the "Svet" type.

This work was aimed at studying the transport and selective characteristics of nanofiltration membrane of the OPMN-K type with respect to solutions contained catamine AB and amine oxide for development of promising systems of water regeneration as well as at evaluating the effect of the concentrations of solutions and working pressure of the regeneration unit on these characteristics. It is found that the selectivity of membrane with respect to the solutions contained the single constituents (catamine AB or amine oxide) considerably differed from the selectivity of membrane with respect to solution containing the mixture of catamine AB and amine oxide. Studies of this membrane give the satisfactory results in transport and selective characteristics of all tested solutions excluding the solution containing catamine AB with low concentrations. The obtained results indicate that nanofiltration may be considered as a perspective step of reclamation of sanitary-hygienic water in space flight environments.