Effluent management in industrial operations
Effluent disposal performance
Total effluent discharge in the surface water category fell by 3% compared to the previous year. In seawater, the variation was minimal between the last two years. In 2023, we had some instabilities in the processes, which led to a reduction in the volume of effluents. The specific discharge went from 22.4 m³/t in 2022 to 22.9 m³/t in 2023.
Effluent quality
In general, the priority substances of concern are determined by the requirements of environmental agencies or control needs inherent to the region where the industrial process is installed. We decided to disclose to our external stakeholders the effluent analysis parameters established as a reference in the European Commission's Integrated Pollution, Prevention and Control (IPPC) international methodology for the pulp and paper sector (2015). Below, we will present the performance of each parameter, as well as a comparison of Suzano's performance and the IPPC reference values.
BOD Performance
In 2023, Suzano's Biological Oxygen Demand (BOD) load was 7,330.7 tons, which represented a 13% increase over the load reported in 2022 (6,485.5 tons). The Três Lagoas unit was mainly responsible for the increase, as it had to make some adjustments to the hydraulic detention time of the polishing lagoon, which led to a 30% increase compared to the previous cycle. However, this issue did not have a significant impact on the specific indicator, which rose from 0.6 kg/t to 0.7 kg/t and remained within the international reference standards: between 0.3 and 1.5 kg/t, established by the IPPC.
COD Performance
In 2023, Suzano's Chemical Oxygen Demand (COD) load was 69,325.1 tons, which represented a 7% reduction compared to the load reported in 2022 (74,315.7 tons). The specific indicator remained in line with the previous cycle, dropping from 6.5 kg/t in 2022 to 6.4 kg/t in 2023. The figure is below the target set at the industrial units (7.00 kg/t) and remains within the international reference standards: between 8.00 and 23.00 kg/t, established by the IPPC.
TSS Performance
In 2023, Suzano's Total Suspended Solids (TSS) load was 8,817.9 tons, which represented a 4% increase over the load reported in 2022 (8,480.3 tons). The specific indicator remained in line with the previous cycle, rising from 0.7 kg/t in 2022 to 0.8 kg/t in 2023. The results are in the reference range of the international standards established by the IPPC, which points to results between 0.6 and 1.5 kg/t as the best performance.
AOX Performance
In 2023, there was a 10% reduction in the load of organohalogen compounds (AOX) compared to 2022, from 490.0 tons to 439.8 tons. We have seen stability in the specific indicator, which has remained at 0.04 kg/t over the last two years. The figure is well below the minimum reference of international standards (up to 2.5 kg/t), established by the IPPC, and more restrictive standards (up to 0.16 kg/t), such as those defined by the United States Environmental Protection Agency (USEPA) and the target set internally (equal to or below 0.15 kg/t).
Suzano does not use elemental chlorine in its pulp-bleaching operations. Our operations use Elemental Chlorine Free (ECF) technology, and the Jacareí factory also has Total Chlorine Free (TCF) technology.
Phosphorus Performance
In 2023, Suzano's phosphorus load was 284.5 tons, in line with the load reported in 2021 (281.7 tons). We saw a 33% increase in the specific indicator, which went from 0.02 kg/t to 0.03 kg/t. The results are in the reference range of the international standards established by the IPPC, which points to results between 0.01 and 0.03 kg/t as the best performance.
Nitrogen Performance
In 2023, there was a 10% reduction in the nitrogen load compared to 2022, from 1,213.1 tons to 1,089.0 tons. We observed stability in the specific indicator, which remained at 0.10 kg/t. The results are in the reference range of the international standards established by the IPPC, which points to results between 0.10 and 0.25 kg/t as the best performance.
The following information is available in the tables below:
- Total water discharge by source;
- Direct biochemical/biological oxygen demand (BOD) in effluents;
- Direct chemical oxygen demand (COD) in effluents;
- Presence of total suspended solids in effluents;
- Presence of AOX in effluents;
- Presence of total phosphorus in effluents;
- Presence of total nitrogen in effluents.
Total water discharge by source
| 2020¹ | 2021¹ | 2022 | 2023 | |||||
|---|---|---|---|---|---|---|---|---|
| Total | In water-stressed areas² | Total | In water-stressed areas² | Total | In water-stressed areas² | Total | In water-stressed areas² | |
|
Surface water |
174.723.236,65 |
23.303.984,81 |
173.135.366,05 |
23.247.908,59 |
173.195.872,33 |
22.765.500,30 |
194.665.634,00 |
0,00 |
|
Sea water³ |
51.049.305,24 |
0,00 |
56.620.327,24 |
0,00 |
58.876.216,66 |
0,00 |
58.791.347,00 |
0,00 |
|
Third-party water ⁴ |
n/d |
n/d |
n/d |
n/d |
n/d |
n/d |
3.676,80 |
1.277,60 |
|
Total |
225.772.541,89 |
23.303.984,81 |
229.755.693,29 |
23.247.908,59 |
232.072.088,99 |
22.765.500,30 |
253.460.657,80 |
1.277,60 |
- The surface water category covers fresh waters, i.e. with total dissolved solids ≤1,000 mg/L.
- By 2022, the city of Suzano (SP) has been classified as a water stress area by the Aqueduct Water Risk Analysis. Therefore, the values of the Suzano and Rio Verde units fell into this category from 2020 to 2022. In 2023, a review was carried out and only Maracanaú (CE) was classified as a water stress area using the same tool.
- The Aracruz (ES) unit has an underwater outfall and discharges effluent into the sea.
- The Maracanaú and Cachoeiro de Itapemirim (ES) units only use water from the municipality's water utility for administrative activities. As a result, in 2023 we started reporting the water used by these units in this category. In previous years, this data was reported in surface water.
Direct biochemical/biological oxygen demand (BOD) in effluents
| 2020 | 2021 | 2022 | 2023 | |
|---|---|---|---|---|
| média | média | média | média | |
|
Tonnes |
4.780,39 |
6.384,70 |
6.485,49 |
7.330,70 |
|
mg/L |
18,57 |
25,24 |
25,45 |
37,70 |
|
kg/t |
0,46 |
0,57 |
0,57 |
0,70 |
Direct chemical oxygen demand (COD) in effluents
| 2020 | 2021 | 2022 | 2023 | |
|---|---|---|---|---|
| média | média | média | média | |
|
Tonnes |
72.609,80 |
74.486,64 |
74.315,66 |
69.325,10 |
|
mg/L |
282,12 |
294,41 |
291,62 |
356,10 |
|
kg/t |
6,95 |
6,65 |
6,53 |
6,40 |
Presence of total suspended solids in effluents
| 2020 | 2021 | 2022 | 2023 | |
|---|---|---|---|---|
| média | média | média | média | |
|
Tonnes |
8.227,09 |
8.396,76 |
8.480,34 |
8.817,90 |
|
mg/L |
31,97 |
33,19 |
33,28 |
45,30 |
|
kg/t |
0,79 |
0,75 |
0,75 |
0,80 |
AOX presence in effluents
| 2020 | 2021 | 2022 | 2023 | |
|---|---|---|---|---|
| média | média | média | média | |
|
Tonnes |
556,46 |
522,18 |
490,01 |
439,80 |
|
mg/L |
2,16 |
2,06 |
1,92 |
2,30 |
|
kg/t |
0,05 |
0,05 |
0,04 |
0,04 |
Presence of total phosphorus in effluents
| 2020 | 2021 | 2022 | 2023 | |
|---|---|---|---|---|
| média | média | média | média | |
|
Tonnes |
336,48 |
284,96 |
281,72 |
284,50 |
|
mg/L |
1,31 |
1,13 |
1,11 |
1,50 |
|
kg/t |
0,03 |
0,03 |
0,02 |
0,03 |
Presence of total nitrogen in effluents
| 2020 | 2021 | 2022 | 2023 | |
|---|---|---|---|---|
| média | média | média | média | |
|
Tonnes |
1.309,30 |
1.066,03 |
1.213,01 |
1.089,00 |
|
mg/L |
5,09 |
4,21 |
4,76 |
5,60 |
|
kg/t |
0,13 |
0,10 |
0,11 |
0,10 |