Molybdenum contamination dispersion from mining site to a reservoir

2022

IJERPH

A novel diphasic sheeting device (DSD) including complemental feeding stage and complemental disintegrating stage for dislodging features of Cd(II), was investigated. The complemental feeding stage included feeding liquor and Bis(2,4,4 trimethylamyl) dithiophosphonic acid (Cyanex-301) as the carrier in petroleum, and the complemental disintegrating stage included Cyanex-301 as the carrier in petroleum and hydrochloric acid as the disintegrating reagent. The impacts of volumetric ratio of sheeting liquor and feeding liquor(S/F), initial molarity of Cd(II) and ion intensity of the feeding liquor, pH, volumetric ratio of sheeting liquor and disintegrating reagent (S/D), molarity of hydrochloric acid liquor, Cyanex-301 molarity in the complemental disintegrating stage on dislodging of Cd(II), the virtues of DSD compared to the traditional sheeting device, the constancy of system, the reuse of sheeting liquor, and the retention of the sheeting stage were also investigated. Experimental results illustrated that the optimum dislodging conditions of Cd(II) were achieved as hydrochloric acid molarity was 4.00 mol/L, Cyanex-301 molarity was 0.150 mol/L, and S/D was 1:1 in the complemental disintegrating stage, S/F was 1:10, and pH was 5.00 in the complemental feeding stage. The ion intensity of the complemental feeding stage had no distinct impact on the dislodging feature of Cd(II). When initial Cd(II) molarity was 3.20 × 10−4 mol/L, the Cd(II) dislodging percentage was up to 92.9% in 210 min. The dynamic formula was inferred on the basis of the theorem of mass transferring and the interfacial chemistry.

Section: Resultssupporting

confidence: 93%

Section: Introductionmentioning

confidence: 99%

Diphasic Sheeting Device with Cyanex-301 for Dislodging Feature of Divalent Cadmium from Industrial Effluent

Pei

2022

IJERPH

“…Therefore, it is important to understand the migration and transformation law of heavy metals in soil and crops around the black soil ore area. Both domestic and foreign scholars have conducted research on the unconventional water agricultural utilization [17][18][19][20]. However, most of the research focuses on physiological and biochemical effects on crops, and only few of the studies emphasize the quality, crop fruits and soil metal contents [21,22].…”

Section: Introductionmentioning

confidence: 99%

Effects of Unconventional Water Agricultural Utilization on the Heavy Metals Accumulation in Typical Black Clay Soil around the Metallic Ore

Pei

Sun

2022

Toxics

Unconventional water is an important water resource for agricultural utilization in the drought and water shortage of Northeast China. Additionally, exploration in making full use of it is an important way to alleviate water shortage in China. This paper analyzed the effects of unconventional water through field trials on the accumulation of heavy metals in both cucumbers and the typical black clay soil (expressed as black soil) around the Anshan metallic ore. By exploring the effects of unconventional water after secondary treatment on the accumulation characteristics of heavy metals in cucumbers and the heavy metal balance in the soil–crop system under different conditions, the study shows that there are no significant differences in the heavy metal content when the quantity of unconventional water for irrigation varies. Unconventional water for short-term irrigation does not cause pollution to either the soil environment or the crops. Nor will it cause the accumulation of heavy metals, and the index for the heavy metal content is far below the critical value of the trade standard and national standard, which indicates that the crops irrigated with unconventional water during their growth turn out to be free of pollutants. Unconventional water brings less heavy metals into the black soil than crops. The input and output quantities have only small effects on the heavy metal balance in the black soil. This paper provides a reference for the safety control and evaluation of unconventional agricultural utilization.

“…Molybdenum accumulated in sediment may threats aquatic ecosystem and human health via direct input or food chain. The environmental pollution and risks of Mo area around mines have been heavily reported (Timofeev et al 2018;Song et al 2021). In non-mining areas, abnormally high Mo concentration in soils and aquatic system was found as a result of iron, alloys, ceramics, catalysts, lubricants and pigments production and agricultural fertilization (Smedley et al 2017;Ziwa et al 2020).…”

Section: Introductionmentioning

confidence: 99%

Molybdenum background and pollution levels in the Taipu River, China

Mao

et al. 2021

Environ Chem Lett

Pollution of river sediments by industrial molybdenum (Mo) is a potential threat to human and ecosystem health, yet the lack of a geochemical background level for Mo has limited risk assessment. Here, we studied Mo in 25 surface sediments and 8 core sediments in the Taipu River, Yangtze River Delta region, China. We measured total Mo and Mo in acid-extractable, reducible, oxidizable and residue fractions. Results show a background Mo level of 0.35 mg/kg of natural Mo in core samples. Surface sediments are contaminated with an average Mo concentration of 0.58 mg/kg, ranging from 0.22 to 3.47 mg/kg. The highest proportion of Mo in oxidizable, of about 74%, is observed in the most contaminated samples, whereas that of deep subsurface samples is about 22%. Possible pollution sources include dyeing, textile and metal casting.