pH AND CHEMISTRY OF NITROGEN, PHOSPHATE, SULFAR AND ALUMINUM IN SURFACE WATER NEAR TEA PLANTATION

Abstract

High concentrations of NO₃^-, SO₄^2-, phosphate, and Al³⁺ and low pH values were found in spring water which originated from a tea plantation. Although acidic spring water flowed into a local pond, the pH value of the pond water remained above 7 because of photosynthesis, denitrification and sulfate reduction. Photosynthesis caused by an increase of phosphate and NO₃^- concentrations was concluded to have given rise to increases in pH values. Denitrification was thought to have caused the pond to eliminate NO₃^- annually. Sulfate reduction was thought to have caused a disappearance of SO₄^2-. Phosphate was stored within a pond in the form of organic compounds. Al³⁺ was precipitated within the pond because of increases in pH values.