Phosphogypsum as a soil fertilizer: Ecotoxicity of amended soil and elutriates to bacteria, invertebrates, algae and plants (original) (raw)
Related papers
Role of phosphogypsum and NPK amendments on the retention or leaching of metals in different soils
2016
Column leaching tests were conducted to investigate the effects of soil physicochemical characteristics on metal mobility in the subsurface. The metals investigated originated from disposed industrial waste byproducts and from agrochemicals spread over the farmlands. Soil column tests can provide insights into leaching of metals to underlying water compartments. The findings of this study can be used for prevention strategies and for setting risk assessment approaches to land-use and management, and soil and water quality and sustainability. Soils collected from an industrial (IS) watershed and an agricultural (AQ) hydrographic basin were used in soil column leaching experiments. The soil samples were characterized for mineralogy, functional groups, grain size, surface charge, soil type, porosity, and cation exchange capacity (CEC) along with elemental composition. Varying concentrations of phosphogypsum industrial waste or agrochemical (NPK fertilizer) was then added to the surface of the packed columns (n ¼ 28). The columns were subjected to artificial rain over a period of 65 days. Leachates were collected and analyzed for dissolved Na þ , K þ , and Cd 2þ throughout the experimental period, whereas residual Cd content in the subsurface soil was measured at the end of the experiment. Physicochemical characterization indicated that the AQ soil has a higher potential for metal retention due to its fine clay texture, calcareous pH, high organic matter content and CEC. Metal release was more prominent in the IS soil indicating potential contamination of the surrounding soil and water compartments. The higher metal release is attributed to soil physicochemical characteristics. High calcium concentrations of phospho-gypsum origin is expected to compete for adsorbed bivalent elements, such as Cd, resulting in their release. The physicochemical characteristics of the receiving media should be taken into consideration when planning land-use in order to achieve sustainable development. Soil physiochemical characteristics play a key role in determining the behavior and fate of elements upon application of amendments. Sandy soils should not be assigned to industrial zones or landfills due to their high permeability, unlike fine clay soils. Furthermore, application of fertilizers on sandy soils can threaten groundwater quality, whereas their extensive use on clayey soil can cause soil salinisation.
2020
BackgroundPredominant sandy, Beach Ridges Interspersed with Swales (BRIS) soil is a problematical soil for agriculture. It requires structure and capacity improvement due to its weak composition, low water retention capacity and high leaching of nutrients. However, there are hopes to improve it using different fertilizers in combination with organic matter. Phosphogypsum organic (PG organic) is an agricultural soil conditioner formulated from industrial by-products and organic filler material. This research was carried out to investigate the accumulated levels of heavy metals and radionuclides in water, soil and plants between BRIS soil under PG organic conditioner treatment and normal BRIS soil.ResultsThe result revealed that the PG organic’s particles are as similar to the reported pattern for calcium sulfate hydrate through powder X-ray diffraction (XRD). The heavy metals measured in the surface and borehole water, and soils were below the target values for raw drinking water and...
Journal of environmental biology, 2011
Phosphogypsum (PG) is produced as a solid waste from phosphatic fertilizer plants. The waste slurry is disposed off in settling ponds or in heaps. This solid waste is now increasingly being used as a calcium supplement in agriculture. This study reports the effectof PG amendmenton soil physico chemical properties, bacterial and fungal count and activities of soil enzymes such as invertase, cellulase and amylase over an incubation period of 28 days. The highest mean percent carbon loss (55.98%) was recorded in 15% PG amended soil followed by (55.28%) in 10% PG amended soil and the minimum (1.68%) in control soil. The highest number of bacterial colonies (47.4 CFU g(-1) soil), fungal count (17.8 CFU g(-1) soil), highest amylase activity (38.4 microg g(-1) soil hr(-1)) and cellulase activity (38.37 microg g(-1) soil hr(-1)) were recorded in 10% amended soil. Statistically significant difference (p<0.05) has been recorded in the activities of amylase and cellulase over the period of ...