Study On Composting Of Sludge Mixing Sodium Polyacrylate (PAAS) And Project Design

Researches confirmed that Superabsorbent's adsorbing effect for nutrient and slow-release for fertilizer. As a kind of inexpensive and high quality Superabsorbent, sodium polyacrylate (PAAS) is widely used in land reforming and slow-release fertilizer. Last reseach indicated that PAAS's functions of hydrophilism, swelling and liquid-binding can degrade sludge's water ratio, raise porosity and improve pile's airing condition. And then craft of compost is improved. Consequently, composting process is promoted.This paper taking sewage sludge of Fuzhou as the research object, carried out several researches. First of all, sludge mixed with PAAS was composted in a laboratory composting reactor which is designed. In the aerobic compost device, experiments were carried out to investigate the PAAS's effect of inhibition of nitrogen losses and PAAS's effect to morphous of heavy metal during the composting. The results suggested that adding PAAS have certain effect on preserve nitrogen and deactivation effect on Zn. The PAAS ratio of 1.5% is better than that of 1.0%. Secondly, the middle-scale compost was studied at manure yard. The results suggested that under the PAAS ratio of 1.5% get the best composting effect and composting product has good properties of water-absorbing and water-saving. In addition, the attribute distinction theory and grey correlation analysis approach will be applied to the evaluation of compost maturity. It is correct for model to set up and the calculation process is accurate. The sludge compost maturity level of comprehensive evaluation method offers a relatively standardized, systematic and detailed example of the application to prevent the single index from judging the blindness whether the compost of mud becomes thoroughly decomposed. Moreover, on dividing and appraising the links of confirming of the result in the weight, great improvements have been made to avoid the running off of a large number of information. It is more rational for the weight to divide and it can better reflect the actual conditions of some specific index of the products which may exceed the standards. Finally, taking the sludge from Xiangban, Yangli and Kuai the three wastewater treatment plants as the target experiment, we carry on the disposal of sludge composting project design. Thus, one composting plant which may handle 270t/d has been systematically designed. We complete the corresponding specification and design calculating and the project drawing, and we furthermore carry on the relevant cost regarding as market prediction and economic analysis.