Rescarch Of Ferric-Carbon Microeletrolusis Treatment On High-Density Alcohol Wastewater

As a kind of substitution energy, the prospects of ethyl alcohol for development are extremely broad. The alcohol wastewater has the characteristics that density is high, the quantity is large, it will pollute severely if discharge directly. Along with sewage discharges standard to be strict generously, the traditional anaerobic and aerobic treatment, as the main body craft, failed to satisfy with discharge demand. How to realize high-concentrated alcohol wastewater reaching discharge demand is a current hot topic. It is generally adopted step-anaerobic treatment. However, in the treat process, it produces much greenhouse gas, especially methane, which not only produces greenhouse effect (which is twenty times than carbon dioxide). It produces the greenhouse effect which is harmful to the environment enormously. The reduction of the methane is a new environmental protection tendency. Based on above all, research starts on Fe/C micro-electrolysis + active sludge, the active sludge + Fe/C micro-electrolysis + active sludge conducts the research, which to analyze experiment treat effect and the disposal degree to the greenhouse gas.Through static experimental research, we can get best craft conditions: iron carbon ratio: 3:1; iron water ratio: 125:500; respond time: 2hours, by the way of experiment of orthogonal array and single factor analysis, according to that which can guide engineering practice.In the experiment of"Fe/C micro-electrolysis + active sludge", Fe/C micro-electrolysis is adopted as the pretreatment method, i.e. Fe/C micro-electrolysis +electro-flocculation. After the treatment, the value of CODcr decreases from 40000⁵0000mg/L to 14000mg/L. The best CODcr removal ratio is 70%. After that, active sludge is adopted to treat the outlet water; the CODcr could descent to 3000mg/L or even lower. The entire COD removal rate of can achieve 90% or above, in this craft combine.In the experiment of"active sludge + Fe/C micro-electrolysis + active sludge", Fe/C micro-electrolysis is adopted as the deep-treatment method, to decompose the high polymer organic matter which is hard to treat by biochemical method, then to increase the value of B/C. After the biochemical treatment within one-half month, the value of CODcr decreases from 40000⁵0000mg/L to 3000mg/L or even lower; When discharge water value of CODcr is stable, the Fe/C micro-electrolysis is adopted so that the value of B/C increase from 0.15 to 0.57, and the value of CODcr reaches1434.24mg/L. The water leakage uses biochemistry processing further, the entire COD removal rate of craft combines achieve 95%, which satisfies the sewage discharge standard in alcohol industry.Based on the mathematical formula of Hover gas production: VCH₄ = 0.35 (QSr - 1.22QX), we can get that the methane quantity presents the correlation to the organic matter density in the water; Fe/C micro-electrolysis as a pretreatment method, the value of TOC decreases in a large scale, i.e. carbon source which forms the greenhouse gas. As a pretreatment method, Fe/C micro-electrolysis CODcr removal rate is generally 50%. According to the Hover formula computation, the withdrawal which the methane gas reduces is 5,565m³/d; the methane greenhouse effect probably is carbon dioxide 20 times, therefore it is equal to carbon dioxide 111,300m³/d.As the pretreatment method, the research carries on the comparison to the Fe/C micro-electrolysis and the conventional coagulation method; when the CODcr removal rate is 50% identically, the traditional coagulation agent need cost 6yuan/m³, whereas the Fe/C cost 0.22yuan/m³.In order to make the alcohol wastewater reach the discharge demand and reduce the greenhouse gas, this test adopts the Fe/C micro-electrolysis'capability of redox and electro-coagulation, as pretreatment and deep-treatment, then bring forward two craft combination, according to the alcohol wastewater characters. Fe/C micro-electrolysis craft operates simply, runs stably, and the cost is inexpensive, and these are craft combination which integrates comprehensive economic efficiency, social efficiency, and environment efficiency.