In the field of sewage treatment, sludge dewatering is a crucial step. The selection of appropriate dewatering agents plays a decisive role in enhancing dewatering efficiency and reducing treatment costs. In recent years, sludge enhancers, as a new type of dewatering agent, have gradually emerged, forming a sharp contrast with traditional common sludge dewatering agents. This article will conduct a comprehensive comparison between sludge enhancers and ordinary sludge dewatering agents from multiple aspects such as composition, mechanism of action, dewatering effect, usage cost and environmental friendliness.
The differences in composition and mechanism of action
Common sludge dewatering agents
Common sludge dewatering agents, such as polyaluminium chloride (PAC) and lime, mainly rely on their chemical properties to react with the components in the sludge, forming flocs, thereby promoting the dewatering of the sludge. For instance, PAC causes sludge particles to aggregate through electro-neutralization, while lime promotes sludge dewatering by adjusting the pH value. However, the mechanism of action of these agents is relatively simple and they are difficult to cope with the complex and variable properties of sludge.
Sludge enhancer
Sludge enhancer is a kind of compound chemical agent, with a more complex and diverse composition, including inorganic compounds, sludge surface structure modifiers, degreasing agents, cell wall breaking agents, etc. These components work in synergy to penetrate deep into the sludge, alter the surface structure of the sludge, reduce the solid surface load and specific surface area of the sludge, effectively destroy the bacterial structure, and thus achieve efficient concentration and dewatering of the sludge. The mechanism of action of sludge enhancers is more comprehensive and in-depth, and they can deal with sludge of various properties.
Comparison of dehydration effects
Common sludge dewatering agents
There are certain limitations in the dewatering effect of common sludge dewatering agents. For instance, although PAC can form a certain amount of flocs, its dosage is relatively large, and the moisture content of the treated sludge remains high, making it difficult to meet the requirements of deep dewatering. Lime, as an alkaline flocculant, can adjust the pH value of sludge and promote dewatering, but it will produce a large amount of residue, increasing the difficulty and cost of subsequent disposal.
Sludge enhancer
In contrast, sludge enhancers perform exceptionally well in dewatering effects. It can reduce the moisture content of sludge from over 90% to 40%-60%, fully achieving sludge reduction. This is attributed to its unique chemical composition and mechanism of action, which can penetrate deep into the interior of sludge, disrupt its structure, and make it easier for water to be separated. Meanwhile, the sludge enhancer can also increase the sludge pressing rate of mechanical equipment by 100% to 500%, shorten the sludge pressing cycle, and further enhance the dewatering efficiency.
Considerations of usage cost and environmental friendliness
Common sludge dewatering agents
The cost of using common sludge dewatering agents is relatively high. On the one hand, the large dosage of medication leads to an increase in the cost of the drugs; On the other hand, the residue after processing needs to be disposed of separately, increasing the cost of subsequent treatment. In addition, some traditional chemicals such as lime can also cause corrosion to the dehydration equipment, shorten its service life and further increase the cost. In terms of environmental friendliness, traditional agents may produce residues of harmful substances, posing a potential threat to the environment.
Sludge enhancer
Sludge enhancers have obvious advantages in terms of usage cost. Due to its small dosage and good dehydration effect, the cost of the agent is relatively low. Meanwhile, the amount of residue after treatment has been significantly reduced, lowering the cost of subsequent disposal. In terms of environmental friendliness, the sludge efficiency enhancer does not contain harmful substances such as chloride ions, has no corrosive effect on dewatering equipment, and will not cause pollution to the environment. This is in line with the current environmental protection policy requirements and is conducive to the sustainable development of enterprises.
In conclusion, there are significant differences between sludge enhancers and ordinary sludge dewatering agents in terms of composition, mechanism of action, dewatering effect, usage cost and environmental friendliness. Sludge enhancers, with their unique chemical composition and mechanism of action, perform outstandingly in dewatering effects. At the same time, they also have obvious advantages in terms of usage cost and environmental friendliness. Therefore, for sewage treatment plants, choosing sludge enhancers as dewatering agents is undoubtedly a wiser choice.