​Effect of Levels and Sources of Sulphur on Growth and Yield Attributes of Sesamum (Sesamum indicum L.) under Rainfed Condition of Nagaland

Background: Sulphur is an important component of plant amino acids, proteins, vitamins as well as enzyme structures which influence the productivity, quality of oil seed and its total oil content. The current study was undertaken to evaluate the role of sulphur and its proper fertilization for better growth, yield and quality of sesamum crop. Methods: The field experiment was laid out in randomized block design (RBD) with three replications and ten treatments viz; T1 (control), T2 (10 kg gypsum ha-1), T3 (20 kg gypsum ha-1), T4 (30 kg gypsum ha-1), T5 (40 kg gypsum ha-1), T6 (control), T7 (10 kg elemental sulphur ha-1), T8 (20 kg elemental sulphur ha-1), T9 (30 kg elemental sulphur ha-1) and T10 (40 kg elemental sulphur ha-1). Result: From all the treatments, T10 (40 kg elemental sulphur ha-1) recorded the highest plant height (cm), plant dry weight (g plant-1), crop growth rate (g m-2 day-1), number of capsule plant-1, length of capsule (cm), number of seed capsule-1, stover yield (kg ha-1), seed yield (kg ha-1) and harvest index (%).

Biochar and Sulphur Enriched Digestate: Utilization of Agriculture Associated Waste Products for Improved Soil Carbon and Nitrogen Content, Microbial Activity, and Plant Growth

A number of agriculture residues may be used either directly or after suitable treatment as amendments to improve soil quality. Such materials include biochar made of agriculture residues, digestate or elemental sulphur obtained from biogas desulphurisation. The joint use of these materials via pre-incubation may be more advantageous than only mixing prior the application to soil. In this study, digestates were mixed with amendments and incubated for 6 weeks before application to soil in a short-term pot experiment with lettuce (Lactuca sativa). The following treatments were tested: control digestate, digestate + biochar, digestate + elemental sulphur, digestate + biochar + elemental sulphur. The biochar-enriched digestate significantly increased soil microbial biomass, soil C:N, fresh above ground biomass, fresh and dry root biomass. Elemental sulphur-enriched digestate caused highest arylsulfatase and phosphatase, increased urease, microbial biomass in soil and fresh root biomass. Amendment of digestate + biochar + sulphur led to the significantly highest total soil carbon, microbial biomass, β-glucosidase, urease, and increased C:N ratio, arylsulfatase in soil and root biomass. It mitigated the adverse effect of either biochar or elemental sulphur on soil respiration. Properties of digestates were apparently affected by pre-incubation. This approach in digestate fertilizer production may contribute to sustainable farming.

Effect of Oxygen and Nitrogen Sparging during Grape Fermentation on Volatile Sulphur Compounds

Elemental sulphur is a common fungicide applied in vineyards before harvest, and has been found toincrease the production of desirable polyfunctional mercaptans, but also H2S and unwanted reductivesulphur aroma compounds. This paper investigates the effectiveness of oxygen and nitrogen sparging,applied during fermentation, on the removal of volatile sulphur compounds in Sauvignon blanc wines.Increasing the amount of elemental sulphur added to grapes after pressing, from nil to 10 to 100 mg/L,led to an increase in the formation of 3-mercaptohexanol (3MH), of 3-mercaptohexyl acetate (3MHA) forthe 10 mg/L additions only, and of some unwanted reductive compounds. Few changes were observed inthe concentrations of aroma compounds when the juices were sparged with nitrogen during fermentation.Additions of oxygen during fermentation led to some decrease in the concentration of polyfunctionalmercaptans for the 10 mg/L sulphur additions, but did not significantly remove reductive aroma compounds.Few differences were observed in the concentration of wine phenolics or of further wine aroma familieswith any of the treatments.

Deposition of Arsenic from Nitric Acid Leaching Solutions of Gold–Arsenic Sulphide Concentrates

At present, the processing of refractory gold–arsenic sulphide concentrates is becoming more relevant due to the depletion of rich crude ore reserves. In the process of the nitric acid leaching of arsenic sulphide minerals, solutions are formed containing 20–30 g/L of arsenic (III). Since market demand for arsenic compounds is limited, such solutions are traditionally converted into poorly soluble compounds. This paper describes the investigation of precipitating arsenic sulphide from nitric acid leaching solutions of refractory sulphide raw materials of nonferrous metals containing iron (III) ions using sodium hydrosulphide with a molar ratio of NaHS/As = 2.4–2.6, which is typical for pure model solutions without oxidants. The work studied the effect of temperature, the pH of the solution and the consumption of NaHS and seed crystal on this process. The highest degree of precipitation of arsenic (III) sulphide (95–99%) from nitric acid leaching solutions containing iron (III) ions without seed occurs with a pH from 1.8 to 2.0 and a NaHS/As molar ratio of 2.8. The introduction of seed crystal significantly improves the precipitation of arsenic (III) sulphide. An increase in seed crystal consumption from 0 to 34 g/L in solution promotes an increase in the degree of transition of arsenic to sediment from 36.2 to 98.1% at pH = 1. According to SEM/EDS and XRF sediment data, from the results of experiments on the effect of As2S3 seed crystal consumption, acidity and molar ratio of NaHS/As on the precipitation of arsenic (III) sulphide and the Fetotal/Fe2+ ratio in the final solution, it can be concluded that the addition of a seed accelerates the crystallisation of arsenic (III) sulphide by increasing the number of crystallisation centres; as a result, the deposition rate of As2S3 becomes higher. Since the oxidation rate of sulphide ions to elemental sulphur by iron (III) ions does not change significantly, the molar ratio of NaHS/As can be reduced to 2.25 to obtain a precipitate having a lower amount of elemental sulphur and a high arsenic content similar to that precipitated from pure model solutions.

Static wetting angles of water and sulphur at the zinc sulphide surface modified with anionic surfactants and their combinations

This paper looks at the effect produced by surface modification of the super pure zinc sulphide monocrystals with certain surfactants and their combinations (sodium lignosulphonate (SLS), sodium dodecyl sulphate (SDS), sodium dodecylbenzenesulphonate (SDBS) and the following combinations: SLS + SDS, SLS + SDBS on the surface angle of wetting with water and elemental sulphur melt. It was found that as the concentration of individual surfactants in the solution rose, so did the wetting ability of the mineral surface. Thus, at the surfactant concentration of 0.8 g/dm3 the water wetting angle reaches 48.4o for SLS, 22.5o for SDS and 10.3o for SDBS; the elemental sulphur wetting angle is 71.3o for SLS, 76.9o for SDS and 67.9o for SDBS. The work of adhesion in the system ZnS – Surfactant – Н2О increases by 9–11%, and in the system ZnS – Surfactant – S0 — by 5–8%. When using the combinations SLS + SDS (СSLS = 0.2–0.8 g/dm3) and SLS + SDBS (СSLS = 0.2 g/dm3), inverse surface wetting of zinc sulphide with elemental sulphur melt is observed. The maximum wetting angles reached are 93o and 85o, correspondingly. The work of adhesion and the spreading coefficient expectedly decrease. The paper analyzes the effect of individual surfactants and their combinations on the pressure leaching of zinc sulphide concentrate. The use of individual surfactants intensifies the transition of valuable components into the solution. The biggest increase in recovery was seen when using SLS, and namely 27–32% for zinc and 11–16% for copper. The recovery of zinc increased by 31–41% in the presence of SLS + SDS and by 27–34% in the presence of SLS + SDBS. This research was funded by the Russian Science Foundation, Grant No. 18-19-00186.

Potential copper plant Vanyukov furnace gas desulphurization capacity

To enable maximum disposal of Vanyukov furnace flue gas, the authors of this paper examined the spare capacity of the Elemental Sulphur Site at the Copper Plant of Nornickel’s Polar Division. Thus, the paper considers an optimized three-stage flue gas treatment process (which also includes a thermal reduction stage) and the possibility to skip the stage of preliminary condensation of sulphur from reduced gas. To estimate how it will affect the overall recovery of sulphur (desulphurization factor), a series of calculations was carried out to compare the Elemental Sulphur Site’s performance during two different treatment processes: a complete process that includes preliminary condensation of sulphur from thermally reduced gas; and a short process, i.e. without preliminary condensation of sulphur. In both cases, the concentration of sulphur dioxide in the Vanyukov furnace gas was [SO2] = 28 vol %. The results of the calculations were verified through experiments conducted on a pilot unit owned by Gipronikel Institute with the gas flow reaching ~1.2 nm3/h, and they confirm the possibility of implementing the three-stage treatment process using the available plant space and reaching the capacity of 40,000 nm3/h and the sulphur recovery of ~89 %. The obtained data on the specific consumption rates of natural gas, oxygen and boiler water can be used for a feasibility study to justify the adoption of the short treatment process at the Elemental Sulphur Site of the Copper Plant of Nornickel’s Polar Division.

Elemental sulphur in the synthesis of sulphur-containing polymers: reaction mechanisms and green prospects

The synthesis of polymers using elemental sulphur as a reagent has been studied in relation to the worldwide overproduction of cyclo-octasulphur.