Study On The Scaling Monitoring Of Circulating Water And The Treatment Of Organic Wastewater

Scaling is a common problem, which is found all over the nature, daily life and most of industrial processes, especially in all heat transfer processes. It not only degrades the performance of heat exchangers, but also increases the consuming power of pumps, thus resulting in tremendous economic loss. CaCO₃ scaling is predominantly present in the circulating water, which has inverse solubility characteristics, resulting in deposition of scales in heat transfer equipment.An experimental study was carried out by an electrical resistance method to determine the effect of copper, N80 steel, 316 stainless steel during CaCO₃ scaling, their relationship with the resistance respectively in different media systems. The paper also studied the relevance between scaling thickness and heat transfer efficiency loss of copper heating tube surface. These provided the technical basis for the choice and preparation of electrode materials of central air conditioning warning control system. The results showed the N80 steel, 316 stainless steel influenced the resistance of electrode scaling layer and its stability because of corrosion in salt water medium system. It was not easy to scale in the edges of copper rod electrodes. So sheet copper was optimal selection for electrode material of heat transfer equipment, owing to its good conductivity and corrosion-resistant.In accelerating the scaling process, when the scaling layer reached more than 0.3 mm, it growed slowly and the layer became more stable. Heat transfer efficiency loss closed to 30% and cleaning should be considered. Under the condition of the same scaling layer, the higher the consentration of scaling ions was, the smaller the resistance was. Carbon steel was not suitable for electrode materials prone to corrosion by SEM and XRD analysis.In organic wastewater treatment research, the research of applying condensate+ ferric-carbon micro electrolysis methods to treat the effluent of biological treatment of landfill leachate from Tianziling landfill of Hangzhou City was introduced in this paper. The optimal conditions condensate sedimentatlon process as follows: initial pH was 8, dosage of condensate agent was 3.5 g/L. Under the optimal conditions, the concentration of CODCr decreased from 656 mg/L to 300 mg/L, the removal rate reached to 54.26%. Through the iron micro-electrolysis experiment in the technical parameters of comparison, the optimal conditions as follows: initial pH was 3, weigh ratio of Fe/C was 2:1. The concentration of CODCr decreased from 300 mg/L to 39 mg/L, the removal rate reached to 87%. Under condensate+ferric-carbon micro electrolysis treatment process, the total removal rate of CODCr concentration reached to 94.05%, and the treatment cost was only 3.68 yuan per ton wastewater.Condensate method was introduced to deal with the effluent of biological treatment of oilfield wastewater from Nanyang. First of all, the organic pollutants of wastewater was agglomerated by the coagulant, and then PAC was added for coagulation and sedimentation, and finally the wastewater was filtered by sand. The amount of PAC was 0.42 kilogram per ton wastewater. Through the above treatments, the oilfield wastewater can get up to less 100 mg/L level of industrial effluent discharge standards.