Air and water pollution management activities

Minimizing water pollutant discharge

DX Division applies legal requirements* and thorough internal standards to minimize the discharge of water pollutants and consistently monitors compliance with its own standards by increasing the frequency of wastewater discharge analysis beyond legal requirements. Additionally, the division ensures that the water pollutant prevention facilities maintain at least 10% spare capacity at all times to prepare for unexpected increases in pollutant influx, thus securing the seamless operation of the facilities.

DS Division applies legal standards* and thorough internal standards to comply with legal regulations on water pollutant discharge. To meet these standards, the division employs optimal prevention technologies, manages the wastewater treatment process in four stages, and purifies the water through advanced treatment facilities before discharging it into local rivers. Furthermore, the division monitors the entire wastewater treatment process from the Central Control Room to maintain strict control over the concentration of pollutants in discharged water. Except for emergency actions like on-site valve control, all treatment steps have been automated.

DS Division is also developing pollutant discharge minimization technologies, aiming to process pollutants to 'natural state' levels in the long term. To reduce chemical usage, the division modifies process recipes, reuses chemicals used in production processes at other facilities, and researches and develops filtration technologies that can selectively separate and remove specific substances. It also continuously works to enhance treatment efficiency by optimizing processes with best available prevention technologies in its wastewater treatment operations. In addition, the division is exploring substitutes for hazardous substances.

• * Act on the Integrated Control of Pollutant-Discharging Facilities

• Minimizing water pollutant
  discharge

  • Reducing chemical usage
  • Developing filters to remove chemical substances
  • Developing substitutes for hazardous substances
  • Improving the efficiency of wastewater treatment process

Establishing a multi-layer defense system for water pollution

DX Division has installed redundant key components in its pollution prevention facilities to ensure uninterrupted operation in the event of a malfunction or other incident. At final rainwater discharge points, the division has deployed containment systems such as automatic gates and valves, as well as monitoring equipment like sensors and CCTVs, enabling the immediate shutdown of pollutant discharge in emergency situations.

DS Division is prepared for possible environmental accidents at wastewater treatment plants. We have installed triple interception facilities across the inlet stage, process stage, and discharge stage of the wastewater treatment plant. Each interlock is activated in real time to initiate an emergency recovery of wastewater when the pollutant concentration is assessed to exceed our standards. This prevents untreated wastewater from being discharged into the river. At the Austin site in the United States, a retention pond, equipped with a real-time pollutant monitoring system, is located upstream of the outlet into the discharge stream. If any untreated pollutants are detected, the discharge outlet is automatically shut off.

• Inlet stage
• Process stage
• Discharge stage

Minimizing Air Pollutant Discharge

We manage air pollutant emissions in strict compliance with legal requirements*, guided by rigorous internal standards. We apply best available technologies and have established a multi-stage treatment system (Stages 1 to 3) according to the characteristics of each pollutant. To prevent unexpected environmental accidents involving air pollutants, backup treatment facilities have been installed across all lines, and a real-time monitoring system has been implemented to proactively address potential issues.

To ensure that air pollutants generated during production are emitted at levels that do not impact the surrounding environment, we are continuously developing and applying pollutant treatment technologies. To reduce nitrogen oxides, we have installed additional wet treatment facilities that combine ozone oxidation and absorption, alongside ultra-low NOx burners and Selective Catalytic Reduction (SCR) systems. We have also replaced existing boilers with low-energy steam supply systems. In addition, we are developing membrane-based adsorption technologies, advanced treatment technologies that utilize ambient and high-temperature plasma and catalyst systems, and integrated treatment technologies designed to enhance treatment efficiency.

• * Act on the Integrated Control of Pollutant-Discharging Facilities