FAHP法在污泥板框调理剂综合评价中的应用

提出了一种新的污泥板框调理剂综合评价方法。传统的CST(毛细吸水时间)、污泥比阻、泥饼含水率等指标只能单一地评价泥饼脱水效果,为了实现对调理效果的综合评价,需要考虑药剂调理费用、运输处置成本、设备处理产能、滤液处理难度等多种因素。通过长期采集中试运行数据,考察了3种污泥板框调理剂对设备、泥饼、滤液和运行4个方面17个指标的影响。引入层次分析法和模糊数学综合评价法相结合的模糊层次分析法(FAHP)对3种污泥板框调理剂进行了综合评价,采用层次分析法确定指标权重;采用隶属函数对指标进行无量纲化处理,确定其隶属度,解决了指标间的可综合性问题;最后用加权平均法得出评价综合值,综合评价值表明,在这3种调理剂中,调理剂1的综合效果最优,更适合作为该厂的污泥板框脱水调理剂。

FAHP method and its application to the comprehensive evaluation of the sludge dehydrate conditioners

This article is inclined to propose a novel method for comprehensive evaluation of the sludge conditioner to be used for the plate-frame filter press dehydrate model. As is known, the main indicators of the sludge dehydrate effect can be shown in the traditional CST,SRF,and its water content rate of the dehydrated sludge cake. For the said purpose,it is necessary to take into account the cost,capacity,filtrate treatment,sludge disposal and some other factors concerned during the sludge treatment,in addition to giving a comprehensive evaluation of the sludge dehydrate conditioners in the plate-frame filter press. What is more, it is also of great necessity to evaluate carefully the dehydrate effect of the 3 kinds of composite sludge conditioners through the fuzzy analytical hierarchical process (FAHP). In proceeding with the comprehensive evaluation,it is necessary to identify and determine the weight value of the 17 indexes by using the AHP, too,to establish the processing capacity of the aforementioned press dehydrate,the operating cost,the filtrate anaerobic ammonia oxidation and the land use of the dehydrate sludge cake so as to define the subordinate functions of the lowest index in correspondence with the consideration of the dehydrate effect. In such a situation,the weight of the hydrate content rate of the dehydrate sludge cake should be expected to be the highest (0. 271 1),just followed by the weight of the amount of sludge access plate-frame dehydrate property (0. 114 9) with the increase of the dry base of the said dehydrate cake (0. 099 9 ). Furthermore,it would be possible to solve the synthesizability among the indexes through the dimensionless processing,so as to formulate the membership interval based on the actual situation of the plant by working out the membership degree by the trapezoidal function. Thus,finally, it would be possible to gain the comprehensive evaluation results with the average weighing method. And,next,it would also be possible to get and determine the comprehensive evaluation value of sludge conditioner 1,which should be equal to 0. 69, whereas that of the sludge conditioner 2-equal to 0. 53 with that of the sludge conditioner 3 being 0. 48. The index system here mentioned can actually cover the influence of the 17 indicators, which may include the water content rate of the dehydrate sludge cake,the dry base increasing rate of the said sludge cake,the cake peeling feature,the conditioning agent cost,the transportation and disposal cost,the amount of the sludge access plateframe dehydrate power,the time of the sludge access plate-frame dehydrate power,the pressing time of the plate-frame dehydrate power,and the frequency of the cleaning agent can all be found generally applicable,in case when the weight and the membership interval can be regulated according to the actual demands. On the other hand,the 8 indexes of EC,the total salt amount, the pH value of the sludge cake,the SCOD of filtrate,the alkalinity of the filtrate, the SS and the Fe ions of filtrate should all be the indexes and subordinate features determined by the actual status-in-situ of the plant. Thus,the evaluation method has been found applicable on the basis to all the specific circumstances, and in turn the method we have worked out should also be expected to provide an effective basis to screen the dehydrate conditioners in the sludge dehydrate industry.