| Nowadays, the straw of agricultural waste has been increasing substantially in light of therapid development of agriculture in China. In modern piggeries, the intensive and large-scaleproducing results in massive increase of piggery wastewater. Without proper treatment,agricultural waste together with piggery wastewater would cause severe contamination to theatmospheric environment, surface water, groundwater and soil environment, thus the agriculturalpollution should not be neglected in China. Yet it was still rather difficult to deal with eitheragricultural waste straw or piggery wastewater independently, since the former waste was ofhigh level of cellulose while the latter with high in ammonium and suspended solids. Therefore,it would be with great value in theoretical research as well as practical production if we treatedwith high-carbon agricultural waste straw and high-ammonium piggery wastewater by usingco-fermentation after mixing the two wastes together with reasonable proportioning.In this paper, the author firstly did absorption research on solution of high concentration ofammonia nitrogen, by adapting natural zeolite in batch experiment. We designed a seven-factor,three-level orthogonal experiment, exploring the impact of the seven factors on the absorption ofnatural zeolite for ammonia nitrogen. These seven factors includes ammonium concentration,particle size of natural zeolite, dosage of zeolite, temperature, pH concentration, dextroseconcentration and stirring rate in the experiment. The optimum value of adsorption wasidentified. Then we dealt with corn straw with electrochemical pretreatment and physicalgrinding pretreatment, adding them into the reactor which had already contained piggerywastewater, natural zeolite and anaerobic sludge, and processed the mixture in form of hybridanaerobic fermentation. We thus explored the variation tendency of diverse chemical indicatorsincluding the pH value of hybrid anaerobic fermentation, Oxidation-Reduction Potential (ORP),Volatile Fatty Acid (VFA), Chemical Oxygen Demand (COD), Gas production and ThreeNitrogen (Ammonia nitrogen, Nitrate nitrogen and nitrite nitrogen) in circumstances of variouspretreatment conditions, particle sizes of zeolite and concentrations of solution. This researchprovided theoretical basis on the anaerobic fermentation technology. The main results of thisstudy were as follow: （1）Research of natural zeolite on the absorption of ammonia-nitrogen. From the orthogonalexperiment, it can be summarized that, in a decreasing order of their influence on theammonia-nitrogen absorption, the seven factors are ammonia-nitrogen concentration, particlesize of zeolite, temperature, pH value, the amount of zeolite added in the reaction, stirring rateand glucose concentration respectively. The optimum value of adsorption is under the conditionof pH equal to7, temperature being55℃, particle size of zeolite being1-2.5mm, the amount ofzeolite added being35g, ammonia-nitrogen concentration at3000mg/L, glucose concentrationat10g/L and stirring rate being150r/min.（2）Hybrid anaerobic fermentation of corn straw and piggery waste water.①With the samecarbon content, the processing effect of electrolyte group was salient. And after adding sufficientextra carbon source, the removal efficiency of COD in piggery waste water was improved.②Within all experimental groups, the maximum gas production was in the fourth one where themesh of corn straw particle size was18to40mesh. The cumulative production was620ml andmaximum daily gas production was67ml. Meanwhile the duration time of gas producing wasthe longest one in all groups, from the fourth day to the thirtieth day.③Natural zeolite hadpositive impact on the absorption of ammonia-nitrogen. By suspending in the solution, thecontact area of zeolite and solution has increased. It also revealed that with corn straw in thesolution the absorption of ammonia-nitrogen was also increased to some extent. |
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