Studies on Uptake by Crops of Lead and Reduction of it's Damage -II. Effect of application of calcium and phosphate materials on Pb Solubility in Soil

농작물(農作物)에 대(對)한 납(pb)의 흡수(吸收) 및 피해경감(被害輕減)에 관(關)한 연구(硏究) -II. 석회(石灰)와 인산물질시용(燐酸物質施用)이 토양중(土壤中) 납(pb) 용출량(溶出量)에 미치는 영향(影響)

A column test was conducted to find out the effect of application of slaked lime, calcium sulfate, calcium superphosphate, and phosphoric acid on the solubility of lead in soil. The soil was adjusted to 310.8 ppm concentration of Pb and applied with amounts of calcium equivalent to 600, 1000, 2000 ppm as slaked lime; sulfate 144, 288, 432 ppm as calcium sulfate; phosphate 95, 190, 285 ppm as calcium superphosphate and phosphoric acid, respectively. The results obtained are as follows: 1. The increasing application of improvement agents reduced the amounts of water soluble Pb in soil. Phosphoric acid was the most effect among to the treatments. 2. The slaked lime treatment has the highest pH of soil and the lowest at the phosphoric acid one. The soil Eh has a reverse tendency the soil pH. 3. Water soluble Ca, $PO_4$ and $SO_4$ contents increased with increasing application amounts of improvement agents in soil. 4. $1N-NH_4$ OAC soluble Pb content in soil was a decreasing tendency in the order of calcium superphosphate, phosphoric acid, slaked lime, calcium sulfate and control after experiment.

토양중(土壤中)에서 납(Pb)의 용출경감효과(溶出輕減效果)를 구명(究明)하기 위(爲)하여 토양(土壤)에 납을 $PbCl_2$로 310.8ppm 처리(處理)하고 경감제(輕減劑)로서 소석회(消石灰), 석고(石膏), 과석(過石), 인산(燐酸)을 처리(處理)하여 담수후(湛水後) 실온(室溫)에 보관(保管)하면서 납 용출량(溶出量) 및 Ca, $PO_4$, $SO_4$와 pH, Eh를 측정(測定)한 결과(結果)는 다음과 같다. 1. 납 용출량(溶出量)은 경감제시용량(輕減劑施用量)이 증가(增加)할수록 감소(減少)되었으며 $H_3PO_4$ 및 과석(過石)이 용출억제효과(溶出抑制效果)가 좋았다. 2. 토양(土壤)의 pH는 소석회(消石灰)가 높고 인산구(燐酸區)가 낮으며 토양(土壤)의 Eh는 반대(反對)의 경향(傾向)이었다. 3. 토양중(土壤中)의 수용성(水溶性) Ca, $PO_4$ 및 $SO_4$ 함량(含量)은 경감제(輕減劑) 시용량(施用量)이 증가(增加)할수록 증가(增加)되었다. 4. 시험후(試驗後) 토양(土壤)의 가용성(可溶性) 납함량(含量)은 과석(過石), 인산(燐酸), 소석회(消石灰), 석고(石膏), 대조(對照)의 순(順)으로 낮은 경향(傾向)이었다.