石化企业污水回用的节水与减排效果分析

ANALYSIS ON WATER SAVING AND WASTEWATER REDUCTION EFFECT OF WASTEWATER REUSE IN PETROCHEMICAL ENTERPRISES

以石化企业当前通行的常规处理回用做循环系统补充水、反渗透脱盐处理用作化水站原水等污水回用模式为基础,从水量平衡、特征组分物料平衡角度,对节水、COD减排、水量减排三方面进行分析,提出以再生水等效系数作为节水指标、以回用减排系数作为减排指标,并推导得出二项指标的计算方法。分析表明,污水回用作循环冷却水时,再生水与新鲜水的特征组分浓度之比是影响节水减排的关键因素;污水经反渗透脱盐处理用作化水站原水时,新鲜水的总溶解固体浓度是影响节水减排的主要因素。

Based on the current wastewater reuse strategies which use wastewater as make-up water for cooling system or feed water for water desalting station after RO treatment,this paper analyzes the water saving effect,COD discharge reduction and wastewater drainage reduction from aspects of flow balance and characteristic ingredient balance,and suggests using equivalent coefficient of reclaimed water as water saving index and drainage reduction factor as wastewater reduction index.Calculation methods of these two indices are deduced.The analysis results indicate that the concentration ratio of characteristic ingredients of reclaimed water and fresh water is the key factor impacting water saving and wastewater reduction effect when wastewater is used as make-up water for cooling system,and the TDS concentration in fresh water is an important factor when wastewater is used as feed water for water desalting station after RO treatment.