Organophosphorus compounds such as diethyl dithiophosphate (DEDTP) are extremely toxic and cause significant environmental and water contaminations in nature. To mitigate its hazardous influence on the wastewater treatment processes, the present study was implemented focusing on the operating variable of the ion Flotation technique. The effects of different parameters including initial pH (4-10), impeller speed (700-1000 rpm), and conditioning time (2-4 min) were investigated to maximize DEDTP removal from synthetic wastewater with an initial amount of 58 ppm. The N-Cetyl-N,N,N-trimethyl-ammonium bromide (CTAB) was used as the collector and frother in the ion Flotation tests. The experimental results were analyzed based on the foamability, foam stability, and turbidity. The ion Flotation experimental results showed that the DEDTP could be removed with the percentage removal of 91 under the optimum operating conditions of pH=10, collector dosage 1.09 ´ 10-3 M, impeller speed 850 rpm, and conditioning time with the collector for 3 min. It was observed that the percentage removal of DEDTP was dependent on the foam properties and electrostatic interactions between CTAB and DEDTP. The turbidity studies proved that DEDTP formed 1:2 complexes with CTAB at pH 10.

The effect of frother dosage (67, 200, and 400 g/t), collector dosage (200, 600, and 1000 g/t), and frother type (Mixed aliphatic alcohol (MAA), Methyl Isobutyl Carbinol (MIBC), and pine oil) on the Flotation performance of three coal samples with various ash contents of 45.1% (high ash content coal, HAC), 36.8% (moderate ash content coal, MAC), and 30.7% (low ash content coal, LAC) was studied. The optimal Flotation conditions for each coal sample were quite different. For HAC, a clean coal with an ash content of 12.8% and a yield of 38% was produced under optimal conditions using MIBC as the frother dosage of 361 g/t, and a collector dosage of 200 g/t. In the case of MAC, a clean coal with an ash content of 10.2% and a yield of 46% was produced under optimal Flotation conditions using MAA as the frother dosage of 148 g/t, and a collector dosage of 200 g/t. For LAC, a clean coal with an ash content of 9.87% and a yield of 57.4% was produced under optimal Flotation conditions using pine oil as the frother dosage of 174 g/t, and a collector dosage of 1000 g/t. For LAC feed coal, in comparison with HAC feed coal, a lower frother at dosage, higher collector dosage, and pine oil frother instead of MIBC must be used. The optimal conditions for HAC Flotation were validated in a coal washing plant. After conducting the necessary modifications to the Flotation reagent scheme, yield, combustive material recovery (CMR) and separation efficiency (SE) of the plant increased by 5.9%, 11%, and 7.5%, respectively which results in more clean coal production of about 14160 t/y.

The particle size distribution plays an important role in the Flotation due to the impact on the bubble-particle collision, attachment, and detachment. In the mechanical Flotation cells, fine particles (generally smaller than 38 microns) have less collision performance and coarse particles (generally larger than 75 microns) have less attachment performance. High turbulence caused a detachment of the particles from the bubbles and thus reduce the performance of the attachment. In the rougher stages of Flotation of sulfide minerals, particles size is the most effective parameter. In the Flotation, the most loses of valuable particles are in the very fine and very coarse particles. In this research in order to improve the zinc recovery in the Flotation circuit of the Bama lead and zinc company, reagent distribution regimen was improved. Therefore, in the laboratory scale, using a design experiment (Taguchi L9), different reagent distribution regimens were compared. The results showed that the adding of 30 g/t of collector (AERO3477) in the rougher stage, along with 15 g/t of Potassium Emyl Xanthate (collector) and 7 g/t of MIBC as frother in the scavenger cells was increased the recovery of fine and coarse particles about 3. 2 and 5. 4 %, respectively. Finally, based on the laboratory results (Taguchi L9), the reagent distribution regimen in the zinc Flotation circuit of the Bama plant was modified. After modifications, the zinc recovery in the fine and coarse particles was increased about 2. 5 and 3. 9 % respectively. Also the zinc assay of final concentrate was increased about 4. 1%.

Microalgae are rich in inorganic compounds and can grow rapidly, thereby producing valuable byproducts in various fields, such as pharmaceutical and food industrials. At the end of the growth phase of the microalgae, one of the problems that exist in harvesting the biomass is lack of a suitable machine for the isolation of microalgae from culture with low-cost is not available. In this study, the Electro-coagulation- Flotation method was used to harvest Chlorella sp. from the culture medium, the impact of three parameters, current, electrolytes and duration of the process was evaluated for its efficiency. The results show that the run time has the greatest impact in harvesting, so that the highest recovery efficiency was attained in the longest time. On the other hand the increase in currency speeds up the clotting and harvesting of the microalgae; but the energy consumption is high. The highest efficiency of biomass harvesting was obtained 88.3 % with a currency of 16 mA.cm-2 and duration of 30 minutes.

The effects of surface dissolution by oxalic acid were investigated on the Flotation kinetics and kinetics of collector adsorption in ilmenite Flotation in the presence of olivine-pyroxene, tremolite-clinochlore and quartz. Fitting of first order kinetic model on the results of Flotation before and after surface dissolution showed that Flotation kinetic constant (K) and ultimate recovery (R∞, ) of ilmenite is increased after surface dissolution and they are decreased for gangue minerals. The results showed that kinetic selectivity index of ilmenite in the presence of olivine-pyroxene, tremolite-clinochlore and quartz are increased from 1. 28 to 1. 98, 1. 42 to 3. 02 and 3. 58, respectively, after surface dissolution indicating the positive effect of surface dissolution process. Investigating the kinetics of collector adsorption showed that the collector adsorption is conforming to second order kinetic model. After surface dissolution, the kinetics of collector adsorption and initial rate of collector adsorption on ilmenite surface is increased from 3. 85 to 8. 44 g. mol-1 min-1 and it is decreased for olivine-pyroxene, tremolite-clinochlore and quartz from 6. 33 to 5. 03, 7. 3 to 6. 22 and 7. 77 to 7. 37 g. mol-1 min-1, respectively. These results are in good agreements with the results of collector adsorption via UV analysis which the collector adsorption on ilmenite surface is increased and it is decreased for gangue minerals after surface dissolution. The results of SEM showed that the surface of ilmenite becomes smoother and uniform and about the gangue minerals, some cavities are produced due to dissolution of surface cations.

During the Flotation operation, recovery may increase, decrease or remain constant with variation of parameters like pH, type and concentration of collector, type and concentration of depressant, % solid in pulp and many others. In this study the attempts have been made to use the Flotation rate data to optimize the above parameters and on account of this, the optimum RTD for such model has been determined. In order to control, evaluate and select the suitable parameter, the separation optimized conditions: PH: 9                                                                                                                                         Depressant: 1000 (g/t)                                                                                                                r.p.m:1000                                                                                                                                 %Solid: 23 Time of d80 = 75: 14 minIt is possible to achieve S.E = 87%  

(A) Aromatic nitrations by tetranitromethane are revealed to be photo chemically offered and are supposed to progress via trinitromethyl nitrite [8].