Assessment of landfill leachate biodegradability and treatability by means of allochthonous and autochthonous biomasses

The biodegradability and treatability of a young (3 years old) municipal landfill leachate was evaluated by means of chemical oxygen demand (COD) fractionation tests, based on respirometric techniques. The tests were performed using two different biomasses: one cultivated from the raw leachate (autochthonous biomass) and the other collected from a conventional municipal wastewater treatment plant after its acclimation to leachate (allochthonous biomass). The long term performances of the two biomasses were also studied. The results demonstrated that the amount of biodegradable COD in the leachate was strictly dependent on the biomass that was used to perform the fractionation tests. Using the autochthonous biomass, the amount of biodegradable organic substrate resulted in approximately 75% of the total COD, whereas it was close to 40% in the case of the allochthonous biomass, indicating the capacity of the autochthonous biomass to degrade a higher amount of organic compounds present in the leachate. The autochthonous biomass was characterized by higher biological activity and heterotrophic active fraction (14% vs 7%), whereas the activity of the allochthonous biomass was significantly affected by inhibitory compounds in the leachate, resulting in a lower respiration rate (SOUR = 13 mg O2 gVSS-1 h-1 vs 37 mg O2 gVSS-1 h-1). The long-term performance of the autochthonous and allochthonous biomasses indicated that the former was more suitable for the treatment of raw landfill leachate, ensuring higher removal performance towards the organic pollutants

DASH diet and prevalent metabolic syndrome in the Hispanic Community Health Study/Study of Latinos

The Dietary Approaches to Stop Hypertension (DASH) diet is recommended for lowering blood pressure and preventing cardiovascular disease (CVD), but little data exist on these associations in US Hispanics/Latinos. We sought to assess associations between DASH score and prevalence of metabolic syndrome (MetS) and its components in diverse Hispanics/Latinos. We studied 10,741 adults aged 18–74 in the multicenter Hispanic Community Health Study/Study of Latinos. Dietary intake was measured using two 24-hour recalls, and MetS defined per the 2009 harmonized guidelines. We assessed cross-sectional associations of DASH score and MetS (and its dichotomized components) using survey logistic regression, and DASH and MetS continuous components using linear regression. We also stratified these models by Hispanic/Latino heritage group to explore heritage-specific associations. We found no associations between DASH and MetS prevalence. DASH was inversely associated with both measures of blood pressure (p < 0.01 for systolic and p < 0.001 for diastolic) in the overall cohort. DASH was also inversely associated with diastolic blood pressure in the Mexican (p < 0.05), Central American (p < 0.05), and South American (p < 0.01) groups; triglycerides (p < 0.05) in the Central American group; fasting glucose overall (p < 0.01) and in the Mexican group (p < 0.01); and waist circumference overall (p < 0.05) and in the South American group (p < 0.01). DASH was positively associated with HDL-cholesterol (p < 0.01) in the Central American group. DASH may better capture diet-MetS associations in Hispanic/Latino subpopulations such as Central/South Americans; this study also adds evidence that Hispanics/Latinos should be analyzed by heritage. Further research, and/or culturally tailored DASH measures will help further explain between-heritage differences