Nanjing University

Nanjing University & Yancheng Academy of Environmental Protection Technology and Engineering

Zixiao Xu

Aimin Li

Qing Zhou

Yeli Jiang

Mengqiao Wang

Chendong Shuang

Wentao Li

Bicun Jiang

Zhaolian Zhu

Weiwei Zhou

Changming Wang

Xinchun Ding

Ke Shen

Baijun Wang

Embodiments herein relate to methods for sludge reduction for pretreatment of nitrotoluene wastewater using electro-catalytic redox. The embodiments may include (a) adjusting a pH of the nitrotoluene wastewater to 1.5 to 2.0, standing for precipitation, draining sludge of the nitrotoluene wastewater at the bottom, obtaining supernatant of nitrotoluene wastewater, placing the supernatant through a cathode inlet into a cathode chamber of an electrochemical reactor; (b) performing electrochemical treatment, wherein reduction reaction of the supernatant of the nitrotoluene wastewater takes place at the cathode chamber, the nitrotoluene wastewater is placed into the anode chamber for oxidation reaction through the cathode outlet, the catholyte tank, and the anode inlet in sequence; (c) adjusting the nitrotoluene wastewater treated in step (b) via the anolyte tank, and then discharging the nitrotoluene wastewater into a biochemical system. The embodiments reduce toxicity of mixed acid nitration wastewater and therefore improve its biodegradability.

Method for sludge-reduced electrocatalytic reduction-oxidation pretreatment of nitrotoluene production wastewater

Provided is a method for resourceful utilization of desorption liquid generated in the resin ion exchange process. This method effectively separates highly-concentrated organics and salts from the desorption liquid and puts these two components into comprehensive utilization.

Method for resourceful utilization of desorption liquid generated in the resin ion exchange process

Implementations herein relate to methods for reducing a desorption solution for regeneration of ion exchange resins in the field of regeneration of resins. The implementations solve problems related to low utilization rates of regeneration agents and high volumes of desorption solutions during the desorption process. The implementations include regenerating the ion exchange resins, and the regeneration solution becomes the desorption solution. After coagulating sedimentation of the desorption solution and slurry separation, a large amount of organic contents are removed from coagulation serum and a large amount of regenerate agents are left. The implementations further include adding the regeneration agent to the coagulation serum to form new or refreshed regeneration solution to regenerate the ion exchange resins. Accordingly, the coagulation serum may be generated from the desorption solution. These operations may be repeated multiple batches for resin regeneration.

Method for regeneration of ion exchange resin causing reduction of desorption solution

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Nanjing, China

Zixiao Xu