Search Results (2)

Healthy soil biota is the key to meeting the world population’s growing demand for food, energy, fiber and raw materials. Our aim is to investigate the effect of green manure as a strategy to recover the macrofauna and the chemical properties of soils which have been anthropogenically degraded. The experiment was a completely randomized block design with four replicates. Green manure, Urochloa decumbens, with or without application of limestone and gypsum, composed the integrated systems. The macroorganisms as well as the soil fertility were analyzed after 17 years of a process of soil restoration with the aforementioned systems. The succession of Stizolobium sp. with Urochloa decumbens, with limestone and gypsum, was teeming with termites, beetles and ants. This integrated system presented the most technically adequate indexes of diversity and uniformity. Multivariate models showed a substantial increase in the total number of individuals due to the neutralization of harmful elements and the gradual release of nutrients by limestone and plaster. These conditioners have undergone multiple chemical reactions with the substrate in order to balance it chemically, thus allowing the macroinvertebrates to grow, develop, reproduce and compose their food web in milder microclimates. It was concluded that the integration of green manure together with grass is an economical and environmentally correct strategy to restore the macrofauna properties of degraded soil in the Brazilian savannah. Full article

The high level of organic elements and nutrients in wet market wastewater (WMW) has raised public concerns. The phycoremediation method, which utilizes microalgae, can be further valorized by converting it into various valuable potential bioproducts. The production of Scenedesmus sp. in WMW was investigated as an ingredient for fish feeds in this study. The potential of two natural plant-based coagulants, Cajanus cajan (pigeon pea) and Cicer arietinum (chickpea), for harvesting microalgae Scenedesmus sp. were compared. Statistical analysis and response surface methodology were used to investigate the flocculant dosage and pH effect on harvesting efficiency. It was found that Cajanus cajan (CC) and Cicer arietinum (CA) both had a harvesting efficiency of 89.29% and 88.56%, respectively. The optimal dosage and pH for CC were 178.75 mg/L and 11.72, and for CA, they were 137.77 mg/L and 9.15. This study indicated that Scenedesmus sp. can remove heavy metals cadmium (87.24%), chromium (85.55%), and ferum (90.35%), respectively. The level of heavy metals content (μg/kg in ppb) in dry biomass was found ultimately low and did not exceed the maximum concentration set up by the European Commission Regulation. The Fourier Transform Infrared (FTIR) analysis of microalgae biomass displayed O-H, N-H and C-H functional groups. The protein–lipid for the potential application as fish feed in the sample was 45.8–43.6% and 15–13%. Moreover, the biomass contained 53% to 40% oleic acid, which is high concentration of fatty acid methyl ester (FAME). As a result, there is high potential of Scenedesmus sp. in wastewater treatment; both natural coagulants give the possibilities for efficient microalgae biomass recovery as fish feed and are applicable for improving the quality of Scenedesmus sp. cultivated in WMW. Full article