Renderable Flocculants for Wastewater Treatment

Date: September 3, 2019

Principal Investigators: Vladimir Reukov and Alexey Vertegel, Clemson University 

Keywords: Flocculants, Wastewater Treatment

Summary:

Every rendering plant has a water treatment system for purification of a wide range of wastewater from rendering, poultry, meat, and food processing, to recover proteins and fats to produce high-quality fats and protein meals, and meet eluent standards. In many cases, the use of flocculants is required to achieve optimum purification efficacy and high total solids content in the sludge. Flocculants are additives that facilitate the removal of particles or colloidal material from a liquid. Most of the currently used flocculants are synthetic and their application in large-scale agriculturally-related processes is becoming a growing concern for consumers, the public, and regulatory entities due to lack of biodegradability and potential toxicity of accumulated contaminants. Since 2017 we have been working with Dr. Rafael Garcia on the development of a novel biodegradable flocculant prepared from blood to replace synthetic compounds. Successful development of a highly efficient biodegradable flocculant will help to address these issues and provide an environmentally friendly way for the treatment of wastewaters generated in rendering processes, and also reduce costs associated with the use of chemicals.

 

The flocculants used in rendering and other wastewater treatment applications are often synthetic polymers, the most common derivatives of polyacrylamide (PAM), a known cause of abundant problems in rendering systems, including coating of cooker surfaces and downgrading of products. While synthetic polymer flocculants are attractive due to their high effectiveness and low cost, there is growing concern regarding the environmental and health impacts of these substances. Consequently, there is currently significant academic and commercial interest in the development of bio-based alternatives to synthetic polymer flocculants. While many bio-based flocculants have been investigated, typically they must be used at considerably higher concentrations in order to achieve equivalent results.

 

We teamed up with Dr. Rafael Garcia (ARS USDA) and developing a novel natural biodegradable flocculant based on hemoglobin recovered from livestock slaughter blood, that can be used as a replacement for PAM. Hemoglobin-based flocculants were found to be as efficient as PAM at similar or lower concentrations. This year we propose to use a modified preparation technique to enhance flocculant efficacy and test its performance in field conditions.

 

Since the initiation of the project, we have carried experiments with biodegradable formulations of flocculants from different blood sources including porcine, chicken, and turkey. We have performed extraction and characterization of flocculants, as well as their testing in the laboratory and field conditions. We have visited a number of rendering and wastewater facilities to study treatment procedures and equipment and performed field tests.

 

Objectives: 

1. Preparation and characterization of biodegradable flocculant from methylated blood hemoglobin using different raw materials (poultry, porcine, bovine) and optimization of preparation procedures. We will work on developing a scalable method of blood protein methylation, characterize and study the efficacy of flocculant prepared from different blood sources.
2. Field testing of prepared flocculant formulations to achieve an appropriate application rate. We will travel to rendering and packing plants to test methylated blood-based flocculant and compare it to currently used synthetic flocculants.