Remote sensing for mapping algal blooms in freshwater lakes: a review

Environmental Science and Pollution Research - A large number of freshwater lakes around the world show recurring harmful algal blooms, particularly cyanobacterial blooms, that affect public health...     

Physical–chemical processes of sustainable materials’ production from hazardous toner waste,galvanic glass waste and spent foundry sand

Journal of Material Cycles and Waste Management - Several sustainable white ceramic composites were prepared from 3 to 7 wt.% of hazardous toner waste, 30–40% of spent foundry sand,...     

Evaluation of surface water quality in aquatic bodies under the influence of uranium mining (MG, Brazil)

The quality of the water in a uranium-ore-mining area located in Caldas (Minas Gerais State, Brazil) and in a reservoir (Antas reservoir) that receives the neutralized acid solution leaching from the waste heaps generated by uranium mining was investigated. The samples were collected during four periods (October 2008, January, April and July 2009) from six sampling stations. Physical and chemical analyses were performed on the water samples, and the data obtained were compared with those of the Brazilian Environmental Standards and WHO standard. The water samples obtained from waste rock piles showed high uranium concentrations (5.62 mg L^?1), high manganese values (75 mg L^?1) and low average pH values (3.4). The evaluation of the water quality at the point considered the limit between the Ore Treatment Unit of the Brazilian Nuclear Industries and the environment (Consulta Creek) indicated contamination by fluoride, manganese, uranium and zinc. The Antas reservoir showed seasonal variations in water quality, with mean concentrations for fluoride (0.50 mg L^?1), sulfate (16 mg L^?1) and hardness (20 mg L^?1) which were low in January, evidencing the effect of rainwater flowing into the system. The concentrations for fluoride, sulfate and manganese were close or above to the limits established by current legislation at the point where the treated mining effluent was discharged and downstream from this point. This study demonstrated that the effluent discharged by the UTM affected the quality of the water in the Antas reservoir, and thus the treatments currently used for effluent need to be reviewed.     

Effects of soil mechanical resistance on nematode community structure under conventional sugarcane and remaining of Atlantic Forest

Nematodes present high potential as a biological indicator of soil quality. In this work, it was evaluated relations between soil physical properties and nematode community under sugarcane cropping and remaining of Atlantic Forest areas in Northeastern Pernambuco, Brazil. Soil samples were collected from September to November 2009 along two 200-m transects in both remaining of Atlantic Forest and sugarcane field at deeps of 0–10, 10–20, 20–30, 30–40, and 40–50 cm. For soil characterization, it was carried out analysis of soil size, water content, total porosity, bulk density, and particle density. The level of soil mechanical resistance was evaluated through a digital penetrometer. Nematodes were extracted per 300 cm³ of soil through centrifugal flotation in sucrose being quantified, classified according trophic habit, and identified in level of genus or family. Data were analyzed using Pearson correlation at 5% of probability. Geostatistical analysis showed that the penetration resistance, water content, total porosity, and bulk density on both forest and cultivated area exhibited spatial dependence at the sampled scale, and their experimental semivariograms were fitted to spherical and exponential models. In forest area, the ectoparasites and free-living nematodes exhibited spherical model. In sugarcane field, the soil nematodes exhibited pure nugget effect. Pratylenchus sp. and Helicotylenchus sp. were prevalent in sugarcane field, but in forest, there was prevalence of Dorylaimidae and Rhabditidae. Total amount of nematode did not differ between environments; however, community trophic structure in forest presented prevalence of free-living nematodes: omnivores followed by bacterial-feeding soil nematodes, while plant-feeding nematodes were prevalent in sugarcane field. The nematode diversity was higher in the remaining of Atlantic Forest. However, the soil mechanical resistance was higher under sugarcane cropping, affecting more directly the free-living nematodes; especially Dorylaimidae which was the most sensible to changes in soil physical properties.