Groundwater phosphorus contamination caused by cultural activities (case study: Babol City)

Background: By economic development of societies and population growth there is an immense need for more food resources. Therefore, artificial fertilizers are a necessity to enhance agricultural productions. Fertilizers could leach into groundwater by man’s cultural activities and contaminate soil and groundwater.Objectives: The main objective in this research is to evaluate the ability of LEACHN model to simulate the phosphorus movement in soil medium causing groundwater contamination.Methods: LEACHN model was used to simulate. The required data to operation of the model are given from the Haraz Extension and Technology Development Center in Mazandaran, Iran.Results: The model was tested in order to verify its prediction value; with a correlation coefficient of 92.3% accuracy. The mean bias error of modeling was equal to -0.087. A sensitivity analysis indicated that the phosphorus concentration in the soil was slightly sensitive to soil saturated hydraulic conductivity changes, but was highly sensitive to changes in soil bulk density.Conclusions: The results showed that the model can accurately simulate phosphorus concentration in soil profile. The result of scenario modeling showed that the amount of phosphorus leakage was directly proportional to precipitation changes and soil permeability.

Potential for Phosphorus Removal in Wastewater Using Volcanic Rock as Adsorbent

Phosphorus contamination in aquatic system was a widespread problem in Zhejiang province due to the excess use of detergent, agrochemicals and other organic phosphorus chemicals. Volcanic rock, an adsorbent with porous structure and large surface area, was applied for phosphorus removal in wastewater. The results showed that the phosphorus removal rate and equilibrium time had positive correlation with the initial phosphorus concentration, while the volcanic rock particle size could also affect the adsorption performance as volcanic rock with smaller particle size used to have a larger cation exchange capacity and higher surface area. Both Langmuir adsorption and the Freundlich adsorption happened throughout phosphorus removal process, showing the strong capacity and capability of volcanic rock as absorbent for phosphorus wastewater. It is promising to use volcanic rock in phosphorus water/wastewater purification systems due its large quantities and accessibility in nature.