Fabrication and evaluation of slow-release lignin-based avermectin nano-delivery system with UV-shielding property

Nanopesticide is one of the best pesticide formulation technologies to overcome the disadvantages of traditional pesticides, which has received great attention from the international community. Using high-speed emulsification and ultrasonic dispersion technology, an avermectin nano-delivery system (Av-NDs) with a particle size of 80–150 nm was prepared through embedding the pesticide molecule utilizing the cross-linking reaction between sodium lignosulfonate and p-phenylenediamine diazonium salt. The formulation and composition of Av-NDs were optimized, the morphology of Av-NDs was analyzed by scanning electron microscope, transmission electron microscope and dynamic light scattering, and the structure of Av-NDs was characterized by UV, IR and 1H NMR. Anti-photolysis and controlled-release tests show that the stability of Av-NDs is 3–4 times of the original avermectin (Av) and possesses the pH-responsive controlled release property. Furthermore, the insecticidal activity of Av-NDs is better than that of avermectin suspension concentrate (Av-SC). The Av-NDs with anti-photolysis and controlled-release characteristics is suitable for large-scale industrial production and is capable to be utilized as effective insecticide in the field.

Performance of sodium lignosulfonate as thickening additive in compositions for matrix acidizing of bottom hole zone

The work considers one of the promising directions for optimizing matrix acidizing using sodium lignosulfonate as a thickening agent. The mechanism of the interaction of acid solutions containing lignosulfonate with carbonate reservoirs is described. The use of sodium lignosulfonate in acid solutions solves several problems. Slowing the reaction rate allows the acid solution penetrate deeper into the formation, with maintaining the HCl concentration. The increased viscosity of the compositions increases the sweep efficiency of the bottomhole zone in the process of matrix acidizing. These two aspects increase the efficiency of matrix acidizing and the permeability of the bottomhole zone. In the course of this work, the chemical reaction rate of sodium lignosulfonate and hydrochloric acid solutions with carbonate core samples were evaluated. Sodium lignosulfonate in an acid solution reduces the dissolution rate of carbonate samples. It is assumed that slowing down the reaction rate allows the acid solution to form long high permeability channels which increases the efficiency of acidizing.

Changes in the content of heavy metals in soils due to the application of waste from the pulp and paper industry

This paper presents the results of a study of changes in the heavy metals content of soils of Karelia (podzolic loamy and peats high moor). Waste from wood processing, pulp and paper industry was added to the soils as organic additives using sodium lignosulfonate as an example. The results showed that no correlation with the additive dose was found in the series of total (Fe, Mn, Cu, Zn, Ti, Al, Ni, Co, Cr, Cd, Mo) and available forms of metals (Cu, Zn, Ti, Al, Ni, Co, Cr, Cd, Mo). Nevertheless, there is a positive correlation between the total and available forms of Pb and the available forms of Fe and Mn (r = 0.9), which can be explained by their initial content in the industrial plant material. It should be noted that the content of all forms of the studied metals did not exceed the requirements of sanitary-hygienic standards and geochemical background typical for soils in Karelia. Keywords: PODZOLIC LOAMY SOIL, PEATS HIGH MOOR SOIL, SODIUM LIGNOSULFONATE, HEAVY METALS