Before understanding wastewater from paper mills, let us first clarify what a paper mill is. A paper mill is a factory that produces paper through mechanized assembly lines, and paper-making mainly includes two methods: manual and mechanized. However, both methods generate wastewater during production. If such wastewater is discharged directly without treatment, it will cause severe water pollution, thereby endangering the ecological environment and human health. Therefore, this article will discuss the monitoring sites for wastewater generated by paper mills, as well as the online water quality monitoring parameters required at different sites.
What are the wastewater monitoring sites in paper mills? They are determined based on actual paper-making processes. For example, paper mills using elemental chlorine bleaching must set up monitoring points at the discharge outlet of the bleaching workshop and the discharge outlet of the bleaching workshop’s treatment facilities. For paper mills with a deinking process that discharges heavy metals, monitoring points should be installed at the discharge outlet of the deinking workshop or the discharge outlet of the deinking workshop’s treatment facilities. Of course, all types of paper mills must set up a monitoring point at the total discharge outlet.
- Parameters to be monitored at the enterprise wastewater discharge outlet:
Flow rate, pH value, chroma, COD (Chemical Oxygen Demand), ammonia nitrogen, suspended solids, volatile phenols, total dissolved solids, etc.
- Indicators at the wastewater discharge outlet of the elemental chlorine bleaching workshop:
Flow rate, adsorbable organic halogens (AOX), etc.
- Parameters to be monitored at the wastewater discharge outlet of the deinking workshop:
Mainly heavy metal indicators.
In fact, many enterprises are involved in online water quality monitoring, not just the paper-making industry. Factories of different industries and production natures produce wastewater with different pollutant contents. Therefore, the monitoring of wastewater indicators must be analyzed according to specific conditions.
