Activated Carbon-microwave Combined Technology To Treat Shellac Wastewater

Lac,also known as shellac,is a purple-red natural resin secreted by lac parasites on trees.It is an important industrial raw material.It is widely used in food,medicine,daily chemical industry,national defense industry,electronic appliances,paint,plastic rubber,publishing and printing,and many other fields.In the process of Lac collagen processing,wastewater will be produced.The wastewater suspended matter,chemical oxygen demand and five-day biochemical oxygen demand of Lac wastewater are high and polluted seriously.At present,natural sedimentation and coagulation sedimentation are often used in the treatment of Lac bleaching wastewater in industry,which can not make the lac wastewater discharge up to the standard,while other treatment methods lack relevant research reports.In view of the characteristics of lac wastewater,the activated carbon with the best removal effect of COD from lac wastewater was selected and activated through experiments.Secondly,the activated carbon-microwave technology was used to treat the lac wastewater,and the removal effect of COD was studied.Finally,the activated carbon-microwave technology was used to investigate the removal effect of TP from lac wastewater.After that,according to the experimental results,the optimum process conditions were obtained:?1?Through experiments,it is determined that the activated carbon activated by hydrochloric acid is beneficial to the removal of COD from lac wastewater,and three kinds of activated carbon are investigated.The activated carbon produced by Chemical Reagent Co.,Ltd.of China Pharmaceutical Group,which has the best treatment effect,is selected.?2?The effect of activated carbon adsorption on the removal rate of COD in LAC wastewater and the effect of microwave irradiation alone on the removal rate of COD in LAC wastewater were investigated through experiments.The combined technology of microwave activated carbon and activated carbon was determined.?3?The effects of microwave irradiation time,microwave power and activated carbon dosage on the removal of COD from lac wastewater by activated carbon-microwave combined technology were determined by single factor investigation.The best technological conditions were irradiation time of 12 min,microwave irradiation of 800W and activated carbon of 15 g.?4?L₉?3³?orthogonal experiment was designed to determine the optimum conditions for the treatment of four kinds of Lac wastewater by the combined technology of activated carbon and microwave.The microwave irradiation time of No.1 Lac wastewater was 12 minutes,the microwave irradiation power was 320W,and the dosage of activated carbon was 15 g.The microwave irradiation time of No.2 Lac wastewater is 12 minutes,the microwave irradiation power is 480W,and the dosage of activated carbon is 15g.The microwave irradiation time of No.3 Lac wastewater was 12 minutes,the microwave irradiation power was 160W,and the dosage of activated carbon was 15 g.The microwave irradiation time of No.4 Lac wastewater was 12 minutes,the microwave irradiation power was 320W,and the dosage of activated carbon was 15 g.Through validation experiments,under the optimum conditions,the average COD of four kinds of Lac wastewater treated were 26.8 mg/L,23.9 mg/L,24.5 mg/L and 28.6 mg/L,respectively.?5?The removal effects of total phosphorus in four kinds of Lac wastewater by activated carbon microwave combined technology were preliminarily explored through experiments.The results show that the combined technology of activated carbon and microwave has a very good treatment effect on the TP of lac wastewater.The residual TP of No.1 Lac wastewater is 0.76mg/L;the residual TP of No.2 Lac wastewater is 0.84mg/L;the residual TP of No.3 Lac wastewater is 0.66mg/L;the residual TP of No.4 Lac wastewater is 0.78mg/L,which can meet the second-class discharge standard of national industrial wastewater.?6?The removal effects of BOD₅ and total nitrogen in four kinds of Lac wastewater by activated carbon microwave combined technology were preliminarily explored through experiments.The results show that the combined technology of activated carbon and microwave has a very good treatment effect on the BOD₅ and total nitrogen of lac wastewater.The residual BOD₅ of No.1 Lac wastewater is 14mg/L and the total nitrogen residue is 10.1 mg/L;the residual BOD₅ of No.2 Lac wastewater is 6 mg/L and the total nitrogen residue is 12.9 mg/L;the residual BOD₅of No.3 Lac wastewater is 12 mg/L and the total nitrogen residue is 7.9 mg/L;the residual BOD₅ of No.4 Lac wastewater is 8 mg/L.The total nitrogen residue is 8.9mg/L,which can meet the first-class discharge standard of national industrial wastewater.The development of this paper provides a useful exploration for the treatment of Lac wastewater,and opens up a new way for the application of activated carbon-microwave combined treatment technology.