鉻化砷酸銅防腐劑之注入與流失（IV）－柳杉材模擬流失試驗

Retention and Leachability of CCA (lV)-Simulate Leaching Test of Japanese Fir

林亞立(Ya-Lih Lin)

《林產工業》 16卷2期 (1997/06) Pp. 200-214

https://doi.org/10.6561/FPI.1997.16(2).6

摘要

本實驗以鉻化砷酸銅（chromated copper arsenate, CCA）type B（保力定K-33）處理之柳杉小角材為試材，利用淋溶試驗法（shower test）模擬處理材在使用場所受雨水淋洗之情形，以了解在不同條件下，試材中CCA的流失性。試驗探討的因子包括了流失時間（30或90天）、土壤類型（砂質壤土、砂土或不與土壤接觸）及流失用水之pH值（3.2或6.0）等。結果顯示，流失時間及土壤類型為影響試材中CCA流失性的主要因子。流失時間愈長，流失量愈大。保水力較好的砂質壤土，使試材流失較多的CCA；保水力較差的砂土，其試材CCA之流失性與不與土壤接觸者之流失性約略相等。流失用水之pH值似乎對試材中CCA的流失性不具顯著影響；然而當pH值為3.2時，pH值與砂質壤土似有複合效應，致使試材中CCA的流失性增加。CCA各成分中以As_2O_5的流失性最高，CuO及CrO_3則視試驗條件而異。試材與砂質壤土接觸時，CuO及CrO_3的流失性約略相等；試材與砂土接觸或不與土壤接觸時，CuO的流失性大於CrO_3的流失性。就土壤因子而言，CuO的流失性不受土壤類型的影響，CrO_3及As_2O_5則於砂質填土的條件下，呈現較高的流失性。此外，pH值為3.2的流失用水，似對CrO_3的流失有促進作用。若將試材由縱向分為地上、地際及地下三部分分析時可知，試材與砂質壤土接觸者，其地際部分CCA的流失性較大;而試材與砂土接觸或不與土壤接觸者，其地上部分CCA的流失性較大。各成分的流失性，不論處理條件為何，CuO及As_2O_5的流失性均以地際部分較多，CrO_3的流失性於各部分均相似。流失試材中CCA及各成分在縱向上均無明顯移動的情形。在橫向上，CCA整體、CrO_3及As_2O_5均有由中央向表層移動的現象，而CuO的移動情形不明顯。

關鍵字

銘化砷酸鋼 ； 流失性 ； 模擬流失試驗

並列摘要

A shower test was conducted in this experiment to understand the effects of leaching time (30 or 90 days), soil types (contact with sand or sandy silt or no soil contact), and the pH value of the leaching water (pH=3.2 or 6.0) on the leachability of chrpmated copper arsenate (CCA) and its components from CCA type B (Bolidin K-33) treated Japanese fir specimens. Results indicated that the leaching time and soil types were the major factors that influenced the CCA leachability of the specimens. Specimens leached out more CCA as the leaching time increased. They also leached out more CCA when in contact with sandy silt than in contact with sand or no contact with soil. The CCA leachability of the specimen which was in contact with sand was approximately the same as the specimen with no soil contact. The effects of soil types on the leachability of CCA from the specimen seemed to be caused by the difference of water retention capacity between sand and sandy silt. The pH of the leaching water used in this experiment did not apparently affect theleachability of CCA from the specimen, however, the CCA leachability of the specimen contacted with sandy silt seemed to be enhanced when the leaching water of lower pH value (3.2)was used. Among the CCA components, As_2O_5 showed the highest leaching percentage, the leachability of CuO and CrO_3 were approximately the same when the specimen was sandy silt contacted. When the specimen was sand contacted or no soil contacted, the leachability of CuO was higher than the leachability of CrO_3. The soil types that the specimens were contacted did not affect the leachability of CuO, however, the leachability of CrO_3 and As_2O_5 were increased when the specimen was contact with sandy silt. The leachability of CrO_3 seemed also to be enhanced when leaching water of lower pH value was used. Soil types also affected the leachability of CCA and its components from different parts of the specimen. Specimens contacted with sandy silt leached' out more CCA from the groundline portion than from the above groung and under ground portions. Specimens contacted with sand or with no soil contact leached out more CCA from the above ground portion than from the groundline and under ground portions. The leachability of CCA components from portions of the specimen was not affected by the soil types that the specimen was contacted. For all the specimens, CuO and As_2O_5 leached out more from the groundline portion than from the other portions, while the leachability of CrO_3 showed no difference among different portions of the specimen. After leaching, no longitudinal movement and redistribution of CCA and its components in the specimen was observed. However, transversly, CCA, CrO_3, and As_2O_5 indicated obvious movement from the center of the specimen to the surface of the specimen, while the movement of CuO was not noticed.

並列關鍵字

CCA ； leachability ； simulate leaching test