ABSTRACT
The removal effects by PAC-MF integrated system for organic matters, pesticides and ammonia-nitrogen are introduced. The separate contribution of PAC, microorganism and MF in the system are detailed quantitatively. The results indicate that the average removal rates of the integrated process for TOC, UV254, THMFP and HAAFP are 73.56%, 96.75%, 77.64%, 83%, respectively, and 95.1% for pesticides dichlorvos, 98% for ammonia-nitrogen. The results illustrate that PAC significantly reduces the membrane organic burden to 28.32% of the direct membrane filtration without PAC; and carbon layer on the surface of membrane has the removal effect for pollutants. Moreover, the PAC used in high concentration can largely improve its adsorption performance for ammonia-nitrogen, whose removal rate is 44.5%.
Subject(s)
Charcoal/chemistry , Water Pollutants, Chemical/analysis , Water Purification/methods , Adsorption , Ammonia/analysis , Ammonia/chemistry , Ammonia/isolation & purification , Organophosphorus Compounds/analysis , Organophosphorus Compounds/chemistry , Organophosphorus Compounds/isolation & purification , Powders , Reproducibility of Results , Ultrafiltration , Water Pollutants, Chemical/chemistry , Water Pollutants, Chemical/isolation & purification , Water Purification/instrumentationABSTRACT
The effects of mixture ratio and hydraulic retention time on mesophilic co-digestion of waste activated sludge and kitchen garbage were investigated, and the mixtures having the ratios of 75%:25%, 50%:50% and 25%:75% on a TS basis, operated at the HRTs of 10d, 15d and 20d. In all the digesters, with an OLR 1.53-5.63 g/(L x d), there were no indication of failure, such as low pH, insufficient alkalinity, ammonia inhibition and accumulation of VFAs. The optimum operating conditions of all the digesters were found to be a mixture of 50%:50% in terms of the stability and performance, buffer capacity was the highest. The volatile solid removal efficiency, specific methane production and methane content in this condition achieved 51.1%-56.4%, 0.353-0.373 L/g and 61.8%-67.4%.
Subject(s)
Food , Sewage , Waste Disposal, Fluid/methods , Bacteria, Anaerobic/metabolism , Biodegradation, Environmental , Bioreactors/microbiology , Methane/analysisABSTRACT
A new type of inorganic coagulant, solid-liquid oxidative poly silicic ferric sulfate (PSF-I), was prepared by adding KMnO4 and stabilizer M to poly silicic ferric sulfate (PSF). The species characteristics of PSF-I, the filtrate of PSF-I and PSF with spectrophotometer, and coagulation performance of PSF-I and the filtrate of PSF-I with jar tests were explored, respectively. Coagulation efficiency of PSF-I was studied compared to that of PSF and poly ferric sulfate (PFS), and the effect of storage time on coagulation performance of PSF-I was investigated. The results show that KMnO4 added to PSF modifies the microstructure of PSF, increasing species size of PSF and making UVA characteristic peaks of Fe3+ ion in PSF-I higher than that in PSF. There exists KMnO4 unattached in PSF-I. The solid phase in PSF-I is a kind of primary nucleus for building up flocs. The optimal dosage with PSF-I is 9 mg x L(-1), in comparison with 12 mg x L(-1) by PSF-I filtrate. The removal of natural organic matters (NOM) is not only caused by adsorption/charge-neutralization and co-precipitation but also by oxidization using PSF-I as coagulant, while to PSF and PFS, adsorption/charge-neutralization and co-precipitation is the only coagulation mechanism.
