With the increase of urban population, urban sewage has increased a lot. Through the investigation of our polyacrylamide producers, the growth and development of urban sewage sludge is very fast in recent years, and the problem of sludge treatment has attracted much attention.

Adding polyacrylamide in city sewage, sludge particle size increased and the sludge & supernatant layer has obvious boundary, the dosage was more than a certain amount, the sludge sedimentation effect began to decline, flocculant adding too much or too little will affect the specific resistance of sludge, so to determine the amount of polyacrylamide according to the actual situation.

The practice shows that the sedimentation rate of sludge is different when the temperature is different. At the same time, the higher the temperature, the faster the sludge settlement. But the actual project production needs to combine the economic benefit, the temperature is too high, the energy consumption is too big, and the benefit can not be maximized.

From 100r / min to 200r / min, with the increase of rotating speed, the final sedimentation volume of sludge is smaller; when the sedimentation volume exceeds 200r / min, the sedimentation volume of sludge begins to rise. When the stirring speed is 150r / min, the sludge moisture content is the lowest and the dehydration effect is obvious.

Under different pH conditions, the sedimentation rate of sludge is different. It has been proved by many practices that the sludge settlement speed is the fastest when the sewage pH is 5. PH too small or too much will affect the sedimentation rate of sludge, we must according to their own actual situation to regulate the PH value of sewage. However, experiment shows that the dewatering performance of the treated sludge under the acid condition is better than the alkaline condition.