RESUMO
Lead (Pb) is a ubiquitous pollutant which poses serious threats to plants, animals and humans once entered into the food chain via contaminated industrial effluents on their discharge into the surface of water bodies and/or geological materials. This study aimed to examine and compare the biosorption potential of natural sugarcane bagasse (NB), pyrolysed sugarcane bagasse (PB) and acid assisted pyrolysed sugarcane bagasse (APB) for the removal of Pb from contaminated water. To explore this objective, a series of batch experiments were conducted at various adsorbent mass (0.25, 0.5, 0.75, 1.0 g per 100 ml contaminated water), initial Pb concentration (7, 15, 30, 60 and 120 ppm), and contact time (7, 15, 30, 60 and 120 min). Results revealed that all the tested bio-sorbents have potential to adsorb and remove Pb ions from the contaminated water. In this regard, APB proved more effective since it removed 98% of Pb from aqueous solution at initial Pb concentration of 7 ppm and mass of 0.25 g per 100 ml of aqueous solution. The respective values in case of NB and PB were 90 and 95%. For a given adsorbent type, Pb adsorption decreased by increasing the mass from 0.25 to 1.0 g per 100 ml of aqueous solution. However, the greatest Pb removal occurred at adsorbent mass of 1.0 g per 100 ml of aqueous solution. Initial Pb concentration had a great impact on Pb adsorption and removal by adsorbent. The former increased and the latter decreased with the increase in initial Pb concentration from seven to 120 ppm. At seven ppm Pb concentration, maximum Pb removal took place irrespective to the adsorbent type. Out of the total Pb adsorption and removal, maximum contribution occurred within 15 min of contact time between the adsorbate and adsorbent, which slightly increased till 30 min, thereafter, it reached to equilibrium. Application of equilibrium isotherm models revealed that our results were better fitted with Freundlich adsorption isotherm model. Overall, and for the reasons detailed above, it is concluded that sugarcane bagasse has capabilities to adsorb and remove Pb ions from contaminated water. Its bio-sorption potential was considerably increased after pyrolysis and acid treatment.
RESUMO
OBJECTIVE: To observe and assess the effect of different dosages of aspirin on inflammatory biomarkers, hemorheology (platelet aggregation rate) and clinical prognosis in patients with acute coronary syndrome (ACS). METHODS: ACS patients were randomly assigned to receive different dosages of aspirin treatment orally. Patients in group A, B and C took 100 mg, 500 mg and 1000 mg of aspirin per day respectively. They were treated and followed-up for 1 year. High-sensitivity C-reactive protein (hsCRP), IL-6, tumor necrosis TNFalpha and platelet aggregation rate were examined and major adverse cardiac events (MACE) were recorded. RESULTS: A total of 312 patients with ACS were enrolled in the study. The baseline characteristics of the three groups were not different with respect to age, gender, cardiovascular risk profile, level of inflammatory biomarkers and concomitant treatment before and after randomization. The levels of baseline serum hsCRP, IL-6 and TNFalpha were higher in subjects of the study as compared with normal reference value (P < 0.05, < 0.05, < 0.01) and they decreased significantly after therapy with 3 different doses of aspirin (detected at 30 days, 6 months and 12 months, P < 0.001), but there were no significant differences among the three groups (P > 0.05). Rehospitalization, MACE and the change of platelet aggregation ratio were not significantly different among the three groups. The incidence of gastrointestinal complaints was significantly higher in groups B and C than in group A (P < 0.05). CONCLUSIONS: The levels of serum inflammatory biomarker increase in patients with ACS. Aspirin therapy may decrease the level of inflammatory markers significantly, but increasing the dosage of aspirin from 100 mg to 1000 mg daily does not decrease the level of inflammatory markers and the clinical MACEs further. However, the incidence of gastrointestinal complaints increase significantly with the increase of aspirin dosage.
