Development and Validation of a Spectrophotometric Method to Measure Sulfate Concentrations in Mine Water without Interference

Abstract

Sulfate concentrations are determined in mine water by gravimetric, titrimetric, colorimetric, turbidometric, ion chromatographic, inductively coupled plasma absorption spectrophotometric, and other methods. Accurate sulfate measurement of mine water can be difficult due to interfering groups, cations, and anions, mainly arsenate (AsO 4 3-) and phosphate (PO 4 3-). In this paper, a simple and effective spectrophotometric method is described for the determination of sulfate in mine water. When the SO 4 2-reacts with barium chloranilate at pH 4.5 in aqueous ethyl alcohol solution, it releases acid-chloranilate, which shows maximum absorption at 350 nm and obeys Beer's law over the concentration range of 10-1,000 mg/L. Results show that the proposed method was significantly more accurate than a conventional method. Absorbance was found to increase linearly with increasing concentration of sulfate, which is corroborated by the calculated correlation coefficient value of 0.999 (n = 7). The slope and intercept of the equation of the regression line were 0.00091 and 0.00778, respectively. The limit of detection and limit of quantification were found to be 0.03861 and 0.06774 mg/L, respectively. The validity of the described procedure was assessed. Statistical analysis of the result indicated high accuracy and good precision. The proposed method was successfully applied in mine water without interference from common groups like AsO 4 3-and PO 4 3-. The relative standard deviations of the proposed method ranged from 0.03 to 0.26%, with recoveries of 99.79-101.57%.

Improvement of biological sulfate reduction by supplementation of nitrogen rich extract prepared from organic marine wastes

“…Based on the known concentration of dissolved sulfide, equation (4) was used to calculate undissociated H 2 S. The lactic acid content in Lactobacillus fermented MWE was measured using colorimetric method as described by Madrid et al (1999). Sulfate concentration was measured by spectrophotometric method (Roy et al, 2011). Interfering agents were removed by treating samples with ammonium molybdate followed by passing them through Dowex-50W-X8 ionic form-H þ column.…”

Assessing the economic viability of wetland remediation of wastewater, and the potential for parallel biomass valorisation

“…Pollution of global waters has been highlighted as one of the major problems facing society. [1][2][3][4][5] The increasing contamination of waterways has wide-ranging damaging impacts, from local ecology to human health. 1,3,5,6 In addition, such contamination has a severe economic impact, with the World Bank estimating that countries need to spend $150bn a year in order to meet sustainability targets.…”

“…[1][2][3][4][5] The increasing contamination of waterways has wide-ranging damaging impacts, from local ecology to human health. 1,3,5,6 In addition, such contamination has a severe economic impact, with the World Bank estimating that countries need to spend $150bn a year in order to meet sustainability targets. 7 Additionally, by 2050 the OECD projects that water demand will have increased by 55% relative to 2000, and climate change is expected to increase water stress globally.…”

“…7 Additionally, by 2050 the OECD projects that water demand will have increased by 55% relative to 2000, and climate change is expected to increase water stress globally. 3,8,9 There is therefore significant pressure for economic and effective treatment and re-use of wastewater.…”

Simultaneous Removal of Residual Sulfate and Heavy Metals from Spent Electrolyte of Lead-Acid Battery after Precipitation and Carbonation

“…were measured with spectrophotometric method (HS-3300 Water analyzer & spectrophotometer, HUMAS) [42], 4500-S 2− method [43], and Raman spectroscopy (DXR Smart Raman spectrometer, Thermo Fisher Scientific Inc.) [44], respectively (detailed information can be found in Supporting Information). The concentration of metal ions (Ca 2+ , Pb 2+ , Cd 2+ , and Fe 2+ ) were measured with Inductively coupled plasma -optical emission spectrometry (ICP-OES) (PerkinElmer ® Optima 5300 DV).…”