Filters filled with a micelle-clay complex mixed with sand were employed to investigate their purification capability of tertiary treated wastewater with loose UF-membranes. The UF membrane was hollow fiber with a mol...Filters filled with a micelle-clay complex mixed with sand were employed to investigate their purification capability of tertiary treated wastewater with loose UF-membranes. The UF membrane was hollow fiber with a molecular weight cutoff of 100 kD. The complex was prepared from the organic cation octadecyltrimethylammonium （ODTMA） and the negatively charged clay-mineral, montmoriIIonite. This complex has a very large surface area, which includes large hydrophobic domains and is positively charged, about half of the cation exchange capacity of the clay. Two sets of filtration experiments were carried out at flow rates of 1.2 and 50 mL/min, which correspond to flow velocities of 3.7 and 153 cm/h, respectively. In the first case, after a passage of 1 L, the turbidity, total suspended solids （TSS）, fecal coliforms （FC）, and total coliforms （TC） were reduced to zero from 14 NTU, 6 ppm, 350 and 10,000 counts per 100 mL, respectively. In the second case, the numbers of FC and TC were reduced from 50,000/100 mL to zero after the passage of 14 L. The values of COD and BOD were reduced several-fold. The conclusion is that the incorporation of micelle-clay filters in the sewage treatment system with loose tertiary capability is promising and warrants larger scale experiments for optimization of the overall system.展开更多
The shortages of chemical fertilizers in Cuba in 90s caused the introduction of different research results obtained on this time for the implementation of natural zeolites in the fertilizer industry. It＇s known as th...The shortages of chemical fertilizers in Cuba in 90s caused the introduction of different research results obtained on this time for the implementation of natural zeolites in the fertilizer industry. It＇s known as the high capacity of cation exchange of the natural Cuban clinoptilolite, which contributes to reducing nutrient losses, such as ammonia, and keeping the potassium and phosphorus cations available. Extensive tests were done on the field with the objective to evaluate the agronomic effect of incorporating this mineral in fertilizer. The results obtained in this experiment contributed to almost all Cuban chemical fertilizers, which has been incorporated around 15%-20% of natural zeolite clinoptilolite in its composition by Cuban agriculture consumes, reducing the chemical carriers of the fertilizers and decreasing the contamination of the environment. Also this mineral contributes for increases in agricultural income more than 15% in all cases; additionally, a trend can be observed towards gradual recovery of some soil fertility indicators, in which the chemical fertilizers with Fertcel was applied.展开更多
文摘Filters filled with a micelle-clay complex mixed with sand were employed to investigate their purification capability of tertiary treated wastewater with loose UF-membranes. The UF membrane was hollow fiber with a molecular weight cutoff of 100 kD. The complex was prepared from the organic cation octadecyltrimethylammonium （ODTMA） and the negatively charged clay-mineral, montmoriIIonite. This complex has a very large surface area, which includes large hydrophobic domains and is positively charged, about half of the cation exchange capacity of the clay. Two sets of filtration experiments were carried out at flow rates of 1.2 and 50 mL/min, which correspond to flow velocities of 3.7 and 153 cm/h, respectively. In the first case, after a passage of 1 L, the turbidity, total suspended solids （TSS）, fecal coliforms （FC）, and total coliforms （TC） were reduced to zero from 14 NTU, 6 ppm, 350 and 10,000 counts per 100 mL, respectively. In the second case, the numbers of FC and TC were reduced from 50,000/100 mL to zero after the passage of 14 L. The values of COD and BOD were reduced several-fold. The conclusion is that the incorporation of micelle-clay filters in the sewage treatment system with loose tertiary capability is promising and warrants larger scale experiments for optimization of the overall system.
文摘The shortages of chemical fertilizers in Cuba in 90s caused the introduction of different research results obtained on this time for the implementation of natural zeolites in the fertilizer industry. It＇s known as the high capacity of cation exchange of the natural Cuban clinoptilolite, which contributes to reducing nutrient losses, such as ammonia, and keeping the potassium and phosphorus cations available. Extensive tests were done on the field with the objective to evaluate the agronomic effect of incorporating this mineral in fertilizer. The results obtained in this experiment contributed to almost all Cuban chemical fertilizers, which has been incorporated around 15%-20% of natural zeolite clinoptilolite in its composition by Cuban agriculture consumes, reducing the chemical carriers of the fertilizers and decreasing the contamination of the environment. Also this mineral contributes for increases in agricultural income more than 15% in all cases; additionally, a trend can be observed towards gradual recovery of some soil fertility indicators, in which the chemical fertilizers with Fertcel was applied.
