Present Situation of Pulping Medium Wastewater Treatment and Research on the effect of Ozone in Pulping Medium Wastewater Treatment
WAN Lan-yu1, ZHANG Lei2, WANG Xin-ming2
( 1. Qingdao Research Center of Ozone Applied Engineering Technology, Qingdao, Shandong 266031;2.Qingdao Guolin Industry Co., Ltd. Qingdao, Shandong 266031)
Abstract: This thesis introduces the method for decolorizing pulping medium wastewater and application of ozone in this field. For cutting down the cost and improving the efficiency, we did a test to pulping medium wastewater by using Physical chemistry---Ozonation---Biological Activated Carbon treatment technology. The solution shows an obvious effect. The decolorization rate can reach 99.6% and all indexes can meet national standard for pollutant emission control.
Keywords: pulping medium wastewater; decolorize; ozonation; biological activated carbon
图1-2 制浆造纸废水生化处理流程图
Fig.1-2 Flow chart of biochemical treatment to pulping medium wastewater
与其他方法相比,生物法具有处理费用低廉和适用范围广的特点,但是也存在处理时间长、占地面积大等缺点,尤其是在废水中存在有毒或难生化降解的有机污染物以及废水量大时,就难以取得理想得处理效果。对于制浆中段废水,由于废水的色度基本上是由制浆过程中产生的木素衍生物所引起的,这些物质都是难于被一般的微生物所降解的高分子有机物。所以,通常用生物法处理后废水的色度和CODcr值还很高。因此生物法处理制浆中段废水的色度还需要进一步研究。
由图4-1可以看出,Ca(OH)2的浓度为1.0g/L和1.2g/L时,色度及CODCr无明显差别,考虑药剂成本问题,把1.0g/L作为絮凝条件。在此条件下,废水的CODCr为929mg•L-1,色度640,pH 12
通过Ca(OH)2的絮凝作用,中段废水中的碳酸盐物质,以碳酸钙的形式析出,同时部分大分子有机物被吸附而沉淀,减轻了后续处理的负担。
2.臭氧氧化实验
将浓度25mg/L、气量2L/min的臭氧通入经絮凝处理的上清液中,同时加入5mLH2O2,在一定的时间间隔取样检测。
表3.2 氧化时间对COD及色度的影响
Tab.3.2 Influence of oxidation time to chroma and COD