The waste gas control of the paper mill in the pulping process is mainly reflected in three aspects:

     First, the odor generated during the pulping production will be sent to the alkali recovery boiler for incineration through a complete sealed transportation system, such as NCG non condensable gas from the pulp line, transpiration tank, causticization and stripper, which contains H2S, CH3SH, CH3SCH3, CH3SSCH3 and other sulfur compounds, as well as turpentine, methanol, steam, nitrogen, oxygen and other gases, Corrosive, toxic and explosive. Therefore, the air quality will be greatly affected if the NCG is not recovered. Jinhai Pulp and Paper Plant sends the NCG generated in the system to the alkali recovery boiler for incineration, which can not only eliminate its severe air pollution, but also effectively recover the sulfur

     Second, the waste gas from pulp bleaching and chemical preparation is chemically treated through the waste gas scrubber, converted into air pollution-free gas, and then discharged into the atmosphere

     The third is the dust generated from the incineration of power boiler, alkali recovery boiler and lime kiln. Efficient electrostatic dust removal equipment is set before the emission of incineration tail gas to remove the dust in between. Their dedusting power exceeds 99%, removing most of the fly ash and dust in the flue, effectively ensuring air quality and human health

     In the technical guidelines for urban pollution prevention and control in China, four criteria are proposed for the selection of sewage treatment technologies:

     ① The urban sewage treatment technology shall be optimized and determined according to the treatment plan, water quality characteristics, environmental functions of receiving water bodies and local actual conditions and needs after all technical and economic comparisons.

     ② The primary technical and economic indicators of technology selection include: investment per unit of water quantity to be treated, investment per unit of pollutant to be reduced, power consumption and cost per unit of water quantity to be treated, power consumption and cost per unit of pollutant to be reduced, floor area, operational function reliability, ease of treatment and maintenance, overall environmental benefits, etc.

     The deodorization method of integrated sewage treatment equipment is not only the conventional high-altitude exhaust, but also the soil deodorization method.

     ③ The influent quality of sewage shall be determined practically and the parameters of technical plan shall be optimized. It is necessary to make a detailed inquiry or measurement on the current water quality characteristics and pollutant composition of sewage, and make reasonable analysis and guess. When the water quality is messy or exceptional, the dynamic experiment of sewage treatment technology should be carried out.

     ④ Choose new technologies with high efficiency and economy vividly and prudently. For new technologies initially applied in China, it is necessary to supply reliable planning parameters through pilot and production experiments before they are applied.