Application of Polyacrylic Acid Sodium in Sludge Sewage Composting
With the increase in population and the popularization of sewage treatment. The disposal of sludge is very important. Many scientists have conducted a series of studies on it. In particular, research on sludge composting and farmland treatment.
The dewatering cake of the sewage treatment plant has high water content, high viscosity, and poor gas permeability. It is necessary to add appropriate proportions of sawdust and rice husks to adjust to a suitable composting state. But at the same time, a lot of refractory substances have been added. The composting cycle is long and the energy consumption of materials is increased. And the loss of nitrogen is serious. It is therefore extremely important to find the right additives and the right process.
Polyacrylic acid sodium (PAAS) is a highly water-absorptive polymer material. In terms of land use, it has the function of retaining water and ensuring fertilizer and improving the soil.
Studies have shown that adding an appropriate proportion of polyacrylic acid sodium to the sludge can improve the sludge structure and increase the porosity of the sludge. To create better-composting conditions. Therefore, the addition of polyacrylic acid sodium has a great impact on the overall composting process and the quality of the compost product.
What Is Sludge Compost?
Composting is a process in which organic matter is continuously degraded and stabilized by the action of microorganisms under certain conditions, and a product suitable for land use is produced.
Composting is generally divided into aerobic composting and anaerobic composting.
Aerobic composting is the decomposition process of organic materials under aerobic conditions. The metabolites are mainly carbon dioxide, water, and heat. Anaerobic composting is the decomposition of organic materials under anaerobic conditions. The final products of anaerobic decomposition are methane, carbon dioxide and many low molecular weight intermediates such as organic acids.
Compared with aerobic compost, anaerobic composting produces less energy per unit mass of organic matter degradation. And anaerobic composting is usually prone to odor. For these reasons, almost all composting systems use aerobic composting.
Composting is actually a form of waste stabilization. But it requires special humidity and aeration conditions to produce the right temperature. This temperature is generally considered to be higher than 45 °C. Maintaining this high temperature can inactivate pathogens and kill weed seeds.
The residual organic matter after reasonable composting has a low decomposition rate and is relatively stable, and the odor of the compost can be greatly reduced. Composting can also produce significant drying effects. This is very useful for handling wet materials such as municipal and industrial sludge. The degradation of the organic substrate in the compost is synchronized with the drying process, which can reduce the cost of subsequent treatment, thereby facilitating the reuse or disposal of the compost.
Composting in the full sense refers to the fermentation of microorganisms under certain conditions of water, C/N and ventilation under artificial control. The process of converting waste organics into fertilizer.
Through the composting process, organic matter changes from an unstable state to a stable humus matter. Its compost product contains no pathogens and does not contain weed seeds. It is odorless and flies free and can be safely handled and preserved. This humus substance is a good soil conditioner and organic fertilizer.
Here is the introduce the use of polyacrylic acid sodium.
1. Quickly stir the water and slowly and evenly add polyacrylic acid sodium powder. (Do not add it in large quantities at a time. Slowly sprinkle the rubber powder into the weighed water, and do not pour the water into the rubber powder. Otherwise, it will easily form a micelle. , difficult to dissolve).
Stir for 10 minutes. After the particles are swollen and suspended. It can be dissolved after 2 hours of rest. Due to the extremely large molecular weight, the dissolution concentration of this product generally does not exceed 2‰.
2. The water of different water quality (soft water, hard water) dissolves polyacrylic acid sodium of the same specification, and the viscosity varies greatly. It is recommended to dissolve in soft water.
3. Effect of salt concentration: The viscosity of polyacrylic acid sodium decreases with the increase of salt concentration.
Special attention should be paid when the impurity ion content in the solvent water is too high and the conductivity is too high. It is easy to react to polyacrylic acid sodium with these impurity ions to form a polyacrylate precipitate.
When the water temperature is too high during the preparation, the polyacrylic acid sodium solid particles in the water are immediately melted and softened. A solid dispersion of polyacrylic acid sodium which is not melted in the outer melt is then formed.
Polyacrylic acid sodium products are generally packaged in paper-plastic composite bags with plastic bags, usually 25 kg/bag, manufacturers will also be customized according to user needs. Under normal circumstances, the shelf life is 2 years, the product is easy to absorb moisture, need to pay attention to moisture and moisture. Store in a cool, ventilated, dry warehouse.