Removal of Organic Matter and Ammonia Nitrogen in Azodicarbonamide Wastewater by a Combination of Power Ultrasound Radiation and Hydrogen Peroxide

A simple and efficient sonochemical method was developed for the degradation of organic matter and ammonia nitrogen in azodicarbonamide wastewater.The effects of initial pH,ultrasound format and peripheral water level on the sonolysis of hydrazine,urea,COD and ammonia nitrogen were investigated.It is found that the initial pH has a significant influence on the degradation of hydrazine and ammonia nitrogen,whereas this impact to urea is relatively small.It also shows that a noticeable enhancement of ammonia nitrogen removal could be achieved in a proper intermittent ultrasound operation mode,i.e.,1/1 min on/off mode.The height difference between the periph-eral water level and the inner water level of the flask affects the efficiency of ultrasonic treatment as well.

Separation of azodicarbonamide from surface of diatomite by froth flotation

The separation of azodicarbonamide(AC)from the surface of diatomite by froth flotation is investigated in this research.Pure samples of diatomite,AC and1:1mixtures of the two were floated in a lab-scale flotation cell withcollector dosage,frother type and dosage,and pH varied to determine the optimum experimental conditions.The diatomite sample and products from flotation tests were characterized using scanning electron microscopy(SEM)equipped with energy dispersive X-ray spectroscopy(EDX).The results of the flotation tests indicate that there is less AC on the surface of diatomite after flotation compared to the feed,while the AC present in diatomite pores remains unchanged.Additionally,Fourier transform infrared spectroscopy(FT-IR)was employed to study the mechanism of interaction between reagents and minerals.

Quantitative Analysis of Azodicarbonamide in Insulation Layers of Extruded Cables by HPLC–UV Detection

Azodicarbonamide(ADC),which has been abundantly used in the creation offoamed plastics as a blowing and foaming agent,has attracted more and more attention in recent years due to the health risks associated with its consumption.ADC is actually on the REACH(Registration,Evaluation,Authorization and Restriction of Chemicals)regulation Candidate List of Substances of Very High Concern,and the residual content in products needs to be confirmed by the end users according to regulations.Therefore,the determination and monitoring of ADC in plastic products is necessary and crucial not only for the growth of ADC global market but also for the health of the public.In this work,a quantitative method for ADC in insulation layers of cables was developed by using optimized total dissolution methodology(TDM)for sample preparation followed by HPLC under HILIC conditions with UV absorbance detection.The linear range of this method was 6–600μg·g^(-1) ,and the limit of detection(LOD)and limit of quantitation(LOQ)were 0.94 and 3.1μg·g^(-1) in solution,respectively.The method has good recovery and precision,and is easy to operate.It meets the needs of the industry and is conducive to the growth of ADC global market.This method is expected to be applicable to ADC quantitation in other polyolefin products.