A series of measurements has been conducted with various combinations of ejector dimensions. Variables were diameter of the nozzle and the distance between the end of the nozzle and the beginning of the pipe. Vacuum head in function of water flow was measured when there was no air flow, and when there was air flow (from a reservoir with constant volume). The results are presented in this paper.

This study investigates the effect of pH, temperature, contact time and initial metal concentration on Cu++ ions removal from water solutions, using biomass of Lagenaria vulgaris skin (LV). With higher pH, the efficiency of copper sorption increases and reaches its maximum at pH 7.0. Temperature has negative effect on sorption process due to its exothermic properties. Biosorption efficiency increases with time and reaches equilibium after 40 min. Increasing initial copper concentration gives an increase in biosorbent sorption capacity, and a proportional decrease in treatment efficiency. Obtained results have shown that LV based biosorbent is an efficient and available mean for toxic metal removal from natural and waste waters.

Anionic clays (layered double hydroxides) comprise positively charged layers with at least two different metal cations, octahedrally coordinated by hydroxyl groups. The positive charges of layered double hydroxides are counterbalanced by interlayer anions. The interlayer anions and water, which fill the interlayer space, are often labile. Therefore, anionic clays exhibit anion exchange capacity (AEC). Anionic clays which have a high surface area and a high anion exchange capacity, are potential adsorbents for anionic contanimants, such as the oxyanion of chrome. The adsorption study of chromium (VI) from aqueous solutions by natural cationic clay mineral (kaolinite, montmorillonite, etc.) was not given much attention, perhaps due to the fact cationic clays have negatively charged layers and clay mineral surface shows no affinity for oxyanion of chrome.