CHEMISTRY SETTING AND ADJUSTMENT

Goals of Chemical Treatment

Note: If the system is equipped with grōCONTROL, refer to appendix B. Otherwise, use following directions:

Large Flocs:

The Microscreen is designed to remove most solids, so it is important to ensure that the size of the flocs is larger than the opening size of the microscreen, which is typically 300 µm. This ensures effective removal of solids from the system.

Strong Flocs:

Strong flocs offer two advantages in the system operation. Firstly, strong flocs are less likely to break when passing through the Microscreen, resulting in lower filtrate Total Suspended Solids (TSS). Secondly, strong flocs enable the screw presses to generate drier screw press solids and cleaner screw press liquids.

To determine the strength of the flocs, you can perform the following test:

1. Collect a sample of flocs from a screen with a 300 µm opening, using one hand.
2. Squeeze the flocs in your hand.
3. If you observe that the flocs are relatively dry, it indicates that the flocs are "strong" and have good dewatering properties.

Initial Chemistry Setting (LWR model)

To ensure optimal system performance, the initial chemistry settings should be configured as specified in the following table. These settings provide a baseline for the system operation. In cases where there are no significant changes in manure conditions (such as Total Suspended Solids (TSS), Total Dissolved Solids (TDS), pH, Total Organic Carbon (TOC), or Conductivity), only minor adjustments may be required to maintain system optimization.

Please refer to the table below for the initial chemistry settings:

Chemistry Setting Adjustment for Microscreen

In the event of a significant change in manure condition, it is necessary to adjust the initial chemistry settings to ensure optimal performance of the Microscreen. Please refer to the table below for guidance on adjusting the chemistry settings.

Note: When operating the First Wave Only:

Note: When operating the First Wave with the Second Wave:

Chemical Overdose

Chemical overdose can occur when the inlet manure becomes relatively cleaner, resulting in a lower inlet Total Suspended Solids (TSS) compared to previous conditions. The main indicator of chemical overdose are sticky screen filtrate and solids. You may also notice that the solids are not dewatering properly through the screen, causing the liquids to "sheet" off the microscreen.

To address this situation, follow these steps:

1. Decrease the grō17 dose by 50 ppm each time.
2. Observe the screen filtrate and solids after each adjustment.
3. Continue decreasing the grō17 dosage until the screen filtrate no longer feels sticky and resembles clear water.
4. Once the screen filtrate is no longer sticky, proceed to optimize the chemistry settings as outlined in the "CHEMISTRY SETTING AND ADJUSTMENT" section at the start of this document.