Effectiveness of vertical subsurface wetlands for iron and manganese removal from wastewater in drinking water treatment plants

Population growth and urbanization pose a greater pressure for the treatment of drinking water. Additionally, different treatment units, such as decanters and filters, accumulate high concentrations of iron (Fe) and manganese (Mn), which in many cases can be discharged into the environment without any treatment when maintenance is performed. Therefore, this paper evaluates the effectiveness of vertical subsurface wetlands for Fe and Mn removal from wastewater in drinking water treatment plants, taking a pilot scale wetland with an ascending gravel bed with two types of plants: C. esculenta and P. australis in El Hormiguero (Cali, Colombia), as an example. The pilot system had three upstream vertical wetlands, two of them planted and the third one without a plant used as a control. The wetlands were arranged in parallel and each formed by three gravel beds of different diameter. The results showed no significant difference for the percentage of removal in the three wetlands for turbidity (98 %), Fe (90 %), dissolved Fe (97 %) and Mn (98 %). The dissolved oxygen presented a significant difference between the planted wetlands and the control. C. esculenta had the highest concentration of Fe in the root with (103.5 ± 20.8) µg/g; while P. australis had the highest average of Fe concentrations in leaves and stem with (45.7 ± 24) µg/g and (41.4 ± 9.1) µg/g, respectively. It is concluded that subsurface wetlands can be an interesting alternative for wastewater treatment in the maintenance of drinking water treatment plants. However, more research is needed for the use of vegetation or some technologies for the removal or reduction of the pollutant load in wetlands, since each drinking water treatment plant will require a treatment system for wastewater, which in turn requires a wastewater treatment system as wel

Testing the Effect of Sodium Bicarbonate Base on Blood Lactate Levels after a Strenuous Exercise

INTRODUCTION: The lactate is an intermediate metabolic, its production in the skeletal muscle increase during the exercise, principally in anaerobic condition that include oxygen deficiency in the skeletal muscle during the exercise. The lactate is released to systemic blood, where it participate in the Cori cycle, although in the blood, the metabolite can modify the blood’s pH. For the last condition, the human has some mechanism to attenuate the lactate effects on the pH in blood PURPOSE: The purpose of this study was evaluate the effect of the sodium bicarbonate ingestion on the lactate blood levels before and after an acute strenuous exercise in undergraduate students. METHODS: Five male (21.2 ± 21.5 years; 78 ± 9.73 kg) were recruited. Two strenuous exercise test of 4 minutes were performed. An interval of 24 hours was present between exercise sessions. The test consisted in intervals of 30 seconds to maximum intensity and with periods of submaximal intensity for 30 seconds. The lower intensity consisted of continuous aerobic activity to ≈ 60% of HRmax. The first test was performed without NaHCO3 ingestion. Contrary, the second exercise session was performed with NaHCO3 ingestion (300mg/kg body weight). The NaHCO3 ingestion was performed 2 hours previous to exercise. RESULTS: Without sodium bicarbonate ingestion, the lactate before physical effort was 1,74mmol, SD 2,15mmol, the lactate after to physical effort was 7,94mmol, SD 9,73, the oxygen in blood before to physical effort was 99% SD 0%, the oxygen after to physical effort was 96,6% SD 1,74%, the systolic blood pressure before physical effort was 122mmHg, SD 11,66mmHg, the diastolic blood pressure was 91,2 mmHg, SD 10mmHg, after physical effort the systolic blood pressure was 131,2mmHg. SD 11,90mmHg, the diastolic blood pressure was 76mmHg, SD 12,58mmHg. With sodium bicarbonate ingest, the lactate before physical effort was 0.4mmol, SD 0.56mmol, lactate after physical effort was 6.73, SD 7,31mmol, the oxygen in blood before physical effort was 99% SD 0%, after to physical effort was 96.66%, SD 0.47%. CONCLUSION: The present study shows that the bicarbonate ingestion does not change significantly the blood lactate concentrations after a strenuous exercise. Our current data could be consequence by the low sample size. Therefore, we suggest perform a new study with a bigger sample than the current work