| In recent years, china’s piggery in scale is increasing and developing in the company of the adjustment of agriculture structure. As a result, it has brought enormous pressure for ecological environment especially water environment. Manure and wastewater emission from farm have become great pollution resource in many urban rural areas. In the previous cases of piggery wastewater processing engineering, recovering energy is adopted manly in the consideration of environmentally-friendly biogas engineering. Feeding pigs in scale could produce enormous waste liquid of marsh gas which is a kind of high-nitrogen and low-carbon refractory organic wastewater. It could pollute surrounding waters and cause difficult environment problems.This thesis takes piggery wastewater as the object to verify the feasibility of iron carbon micro-electrolysis per-treatment for waste liquid of marsh. It intends to offer reference for principle, effect, optimum operation parameters (OOP) through a series of methods such as preliminary test, single factor experiment, and orthogonal test. In the combination of basic iron carbon micro-electrolysis per-treatment principle, iron carbon micro-electrolysis per-treatment has features as following:degrading organics effectively, low cost, waste control by waste, high efficiency and low consumption, simple operation.The thesis gets achievements as follows:(1) Taking an analysis of waste liquid of marsh gas from a piggery in scale in the Chengdu and discover that its concentration of COD, BOD, phosphorus and ammonia nitrogen have exceeded standards and requirements set by the State. COD:N:P is about30:20:1. Therefore, aerobic process isn’t applicable. According to the characteristics ofiron carbon micro-electrolysis per-treatment, it is feasible in the treatment of waste liquid of marsh gas.(2) The experiment has that iron powers and active carbon powers perform good adsorption effects on the phosphorus and ammonia nitrogen. The adsorption of phosphorus and ammonia nitrogen by active carbon powers is in accordance with Freundlich equation. The adsorption of phosphorus and ammonia nitrogen by iron powers is in accordance with Langmuir equation and performing better. The kinetics dynamics model is suitable for adsorption of phosphorus and ammonia nitrogen by active carbon powers and iron powers. Iron carbon micro-electrolysis per-treatment equips the ability of removing phosphorus and ammonia nitrogen. In the lab, the removal rate is30%and15%. Phosphorus and ammonia nitrogen can also degrade COD. However, when in the case of organic wastewater without electrolytes, the removal rate is low.(3) In the single factor experiment, the research on the influence of iron carbon micro-electrolysis per-treatment’s removal effect focus on the suction manner, stirring, temperature, time, iron parried size, pH value and quality of iron and carbon. Every factor plays a different role in the influence of COD, Phosphorus and ammonia nitrogen.(4) In the process of orthogonal test, the research on the comprehensive influence of pH value, time, the ratio of Fe and C under different temperature condition as T=(20±1)℃, T=(30±1)℃, T=(40±1)℃. Taking extremum difference analysis on the data of orthogonal test and discover that the removal effect is the best when T=(20±1)℃, Fe/C is1:1, pH is3and time is120min. the removal rate for COD, ammonia nitrogen and Phosphorus is42.48%,34.01%and97.23%respectively.(5) The engineering practical significance:Hydraulic retention time should be controlled within2h in case that iron and active carbon filter fail; moderate aeration rate can reduce probability of soil hardening; adjusting wastewater pH to3is reasonable; the ration of iron to carbon should always be controlled to1:1even after a period of reaction; small particles can enhance the efficiency; hydraulic retention time can be shorten in the summer and increased in the winter to increase aeration rate. |
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