Characterization of Pulp Bleach Effluents and Their Treatment Using Photocatalytic/Photolytic Agents

紙漿漂白廢水之分析與其光催化分解處理之研究

王益真(I-Chen Wang)

《台灣林業科學》 14卷1期 (1999/03) Pp. 1-12

https://doi.org/10.7075/TJFS.199903.0001

摘要

三十四種南洋闊葉材硫酸鹽漿以傳統C-E-D-E-D五段漂白之前兩段廢水及漿廠D/c。與OE1段廢水經分析其中可吸附有機鹵化物與化學需氧量等污染參數，顯示污染負荷與漿料殘餘木質素量（卡巴值）有關。廢水中溶解木質素以高壓液相層析分析分子量分佈，顯示不同漂白流程與樹種之木質素分子量有不同之分佈。漿廠漂白廢水並以金紅石二氧化鈦、過氧化氫及兩者兼備照射紫外光進行光裂解，照射後廢水之AOX、COD及鉑鈷色度值有顯著降低，可達60%以上之去除率。過氧化氫之處理效果較半導體二氧化鈦為佳，兩者共用有增益之效果。純就成本考量，光催化分解處理恐不具經濟性，但二氧化鈦本身僅催化反應，可長久使用。

關鍵字

可吸附有機鹵化物 ； 漂白廢水 ； 污染防治 ； 光分解劑

並列摘要

The 1st C-stage (chlorination) and 2nd E-stage (alkaline extraction) effluents of 34 bleached tropical hardwood kraft pulps, as well as the V/c-stage (post-oxygen delignification chlorine dioxide/chlorine), and OE1-stage (ensuing oxygenated alkaline extraction) effluents from a pulp mill were examined for their pollutant characteristics. Contents of adsorbable organic halogens (AOX) and chemical oxygen demand (COD) of these effluents tended to increase with the amount of residual lignin (kappa no.) in the pulp. Patterns of molecular weight distribution of dissolved chlorolignins were found to change with tree species and bleaching stage. Among the effluents studied, the relative degree of chlorination was high for low molecular weight substances in the OE1 effluent. Photocatalytic/photolytic decomposition of pollutants in some of the effluents was tested using the rutile form of titanium dioxide, or hydrogen peroxide, and combinations of the two. After UV irradiation for certain periods of time, contents of AOX and COD, and platinum-cobalt (Pt-Co) color units of the effluents were examined and were found to be reduced up to 60%, with hydrogen peroxide showing a more pronounced effect than titanium dioxide. A synergistic effect was observed when both agents were used together. Photocatalytic/photolytic means of destroying recalcitrant pollutants is probably currently economically infeasible, but offers opportunities worthy of further exploration.

並列關鍵字

adsorbable organic halogens (AOX) ； bleach effluents ； pollution abatement ； photocatalysis ； photolysis