Effect of high fluoride groundwater purification by lightweight aggregate scoria

摘要

Problematic excess fluoride groundwater drinking water sources exist in rural northeast China. La(III)-Al(III) soak leaching with heat treatment was used to modify lightweight aggregate scoria to purify high fluoride groundwater. The main elements in scoria were iron, sulfur, oxygen, silicon, aluminum, and calcium. The main mineral compositions were 29.44 % quartz, 30.04 % alkali feldspar, and 40.16 % plagioclase. Ca2+, Mg2+, Fe2+, HCO3-, and F- in water had no influence on the effect of purification. Mn2+ could promote fluoride adsorption and CO32- inhibited defluoridation. Scoria favored Mn2+ and Fe2+ adsorption. The scoria quality and amount of purified outlet water exhibit a linear relationship: Y-amount of purified (water) = 37.499X(adsorbent quality) + 6.092. The fluoride, iron, and manganese concentrations in the study area were 2.00, 3.00, and 1.00 mg/L, respectively. A series of fluoride, iron, and manganese purification process was designed to target economically relatively backward areas and poor-quality drinking water in rural areas of northeast China. Ectopic treatment technology was used in the process system, which provided an important demonstration project model for subsequent research.