Water-Soluble Humic Materials Modulating Metabolism and Triggering Stress Defense in Sinorhizobium fredii

Sinorhizobium fredii CCBAU45436 is a highly effective, fast-growing rhizobium that can establish symbiosis with multiple soybean cultivars. However, it is difficult to maintain the high-density effective viable cells in the rhizobial inoculant for the stressful conditions during production, storage, transport, and application.

Obtaining humic materials by mechanochemical reduction

In the study, a mechanochemical modification of peat was carried out, leading to an increase in the number of functional groups and an increase in the solubility of humic complexes with metals. It was shown that the mechanical activation of peat in the presence of Zn significantly increased the yield of extractable fulvic acids. An analysis of the spectral coefficients showed that humic and fulvic acids extracted from peat were characterized by an increased content of alcohol hydroxyl groups, C–O carbohydrate moieties, and carboxyl groups.

Surface activity of humic substances depending on their origin

Humic substances are a general category of naturally occurring, biogenic, heterogeneousorganic substances that can be characterised as being yellow to black in colour, of highmolecular weight and refractory. Surface tension measurement defined humic substances assurface active substances. Unless micellar structural model of humic substances has beensuggested, in the same time there are only a few studies about the factors that affect thesurface activity of humic solutions. The objective of this study was to study changes insurface activity depending on the origin and properties of humic substances.The surface tension-pH curves of humic substances featured a minimum for all solutions,declining steeply from higher and lower pH values. The decrease in surface tension withdecreasing pH reflects the gradual neutralization of acidic sites, which created amphiphilicspecies that migrated to the surface. Surface tension of solutions of humic substancesdecreased with increasing concentration, as well as in presence of metal salts. Manyindustrially produced humic materials demonstrated no or insignificant impact on surfacetension of their solutions, but humic substances isolated from natural environments (water,soil, peat, sediments) demonstrated significant impact of surface tension of their solutions.Thus there exist direct links between origin, structure of humic substances and their ability toinfluence surface tension of aquatic solutions.

Simulation of NOM events in pilot plant evaluation of DAF/Ozone/BAC for drinking water treatment

Pilot plant testing is invaluable for ascertaining the robustness of water treatment processes against raw water quality events such as turbidity and colour spikes, whether it be for stress testing of an existing process or designing of a new process. Unfortunately, the natural occurrence of such events (particularly colour) can be difficult to predict and commercial humic materials generally fail to closely match the indigenous natural organic matter (NOM) present in the raw water. Therefore, it is highly desirable to be able to simulate NOM event conditions. This paper describes a simple brewing method that we developed and used in our recent pilot plant evaluation of a proposed DAF/Ozone/BAC process for drinking water treatment. Using this method we successfully prepared, by using fallen leaves etc. collected from the local catchment area, large quantities of a concentrated NOM stock solution with its specific ultraviolet absorbance (SUVA), when diluted, very close to the median SUVA of historical NOM events. The brewed solution showed broadly similar NOM characteristics to those of the raw water encountered during the pilot investigation period in terms of molecular weight distribution and fractionation. The coagulation behaviour was also examined for the spiked and non-spiked raw water.

Improvement of Post-Nickel Mining Soil Quality for Plant Revegetation Growth Media through Utilization of Humic materials and Compost PENINGKATAN KUALITAS TANAH BEKAS TAMBANG NIKEL UNTUK MEDIA PERTUMBUHAN TANAMAN REVEGETASI MELALUI PEMANFAATAN BAHAN HUMAT

The purpose of this study was to analyze the effect of humic materials and compost on chemical properties and growth of revegetation plant. The research was conducted at the greenhouse of PT Antam (Persero) Tbk., District Pomalaa, Southeast Sulawesi. Soil analysis was carried out at the Laboratory of Soil Research of Bogor Agricultural University. The experiment was used a completely randomized factorial design with two factors; Humic materials dose (0.00; 0.5; and 1.0 ml / polybag) and compost dose (0.0; 1.0; and 2.5 kg/polybag). Plant indicator that used in this experiment was sengon (Paraserianthes falcataria). The result showed humic materials and compost improved the chemical properties of growth media than control. Treatment with the provision of humic materials only did not fully improved soil chemical properties, while treatments of compost and combination of humic materials and compost able to increase organic C, N-total, CEC, and cations alkaline soil (Ca-dd, Mg-dd, K-dd, and Na -dd). On the plant growth showed that the humic materials and compost gave significant effect on plant height, root length and biomass. Treatment between humic materials and compost had result significant in root length and biomass. The best treatment at the greenhouse was reached by 0.5 ml humic materials and compost 2.5 kg.Key words: chemical property, plant height, root lenght, biomass