Study of sulphate ions removal from acidic waters using ion exchange resin

Acid Mine Drainage (AMD) is the most common pollution related to mining. It consists of an aqueous solution containing high metals and sulphate concentration, which impact surface and groundwater and lead to serious environmental problems. Low pH and high concentrations of heavy metals and sulphates are limiting for many various treatment technologies in these acidic waters. Ion - exchange is a very powerful technology where one or more undesirable contaminants are removed from water by exchange with another non-objectionable or less objectionable substance. Many of materials for the ion - exchange treatment is available in a variety forms and have widely differing chemical and physical properties. The paper deals with study of ion - exchange process under static and dynamic conditions for sulphate removal from acidic waters using ion - exchange resin with the aim to apply the results for treatment of acid mine drainage. Two types of experiments were performed under static and dynamic conditions. The efficiency of AMBERLITE MB20 resin for SO4 2- removal from model solution H2SO4 under static conditions decreases from 86.6 % for concentration 100 mg/L to efficiency 66.9 % for concertation 1000 mg/L. The efficiency for sulphate removal from AMD was only 41%. The study also presents three experiments under dynamic conditions, one with new ion - exchange resin a two experiments with its regenerated form. It was find that ion-exchange capacity decreases numbers of regeneration steps

Metal Pollution Indices of Bottom Sediment and Surface Water Affected by Acid Mine Drainage

Sediments are normally the final pathway of both natural and anthropogenic components produced or derived from the environment. Sediment quality is a good indicator of pollution in the water column, where heavy metals and other organic pollutants tend to concentrate. Metals are introduced in aquatic systems as a result of the weathering of soils and rocks, from volcanic eruptions, and from a variety of human activities involving the mining, processing, or use of metals and/or substances that contain metal pollutants. Heavy metal concentration in the water column can be relatively low in some cases, but the concentrations in the sediment may be elevated. The presented work aimed to investigate the pollutant levels of some heavy metals (Fe, Mn, Al, Cu, Zn, As, Cd, Pb) in the water and sediments related to acid mine drainage (AMD) produced from an abandoned sulphide mine in Smolnik in Eastern Slovakia. A metal pollution index was used to compare the total content of metals at five sampling stations. The level of partitioning of the metals between the surface water and sediments in the area was calculated using Partition coefficients and the correlation coefficients between the metal pairs in both media were calculated by a Pearson coefficient

Low-Carbohydrate Diet among Children with Type 1 Diabetes: A Multi-Center Study

Aims/hypothesis: The proportion of children with type 1 diabetes (T1D) who have experience with low-carbohydrate diet (LCD) is unknown. Our goal was to map the frequency of LCD among children with T1D and to describe their clinical and laboratory data. Methods: Caregivers of 1040 children with T1D from three centers were addressed with a structured questionnaire regarding the children’s carbohydrate intake and experience with LCD (daily energy intake from carbohydrates below 26% of age-recommended values). The subjects currently on LCD were compared to a group of non-LCD respondents matched to age, T1D duration, sex, type and center of treatment. Results: A total of 624/1040 (60%) of the subjects completed the survey. A total of 242/624 (39%) subjects reported experience with voluntary carbohydrate restriction with 36/624 (5.8%) subjects currently following the LCD. The LCD group had similar HbA1c (45 vs. 49.5, p = 0.11), lower average glycemia (7.0 vs. 7.9, p = 0.02), higher time in range (74 vs. 67%, p = 0.02), lower time in hyperglycemia >10 mmol/L (17 vs. 20%, p = 0.04), tendency to more time in hypoglycemia <3.9 mmol/L(8 vs. 5%, p = 0.05) and lower systolic blood pressure percentile (43 vs. 74, p = 0.03). The groups did not differ in their lipid profile nor in current body height, weight or BMI. The LCD was mostly initiated by the parents or the subjects themselves and only 39% of the families consulted their decision with the diabetologist. Conclusions/interpretation: Low carbohydrate diet is not scarce in children with T1D and is associated with modestly better disease control. At the same time, caution should be applied as it showed a tendency toward more frequent hypoglycemia