味精废水中离交废水的预处理技术

Study on Pretreatment Technology of Ion-exchange Wastewater Released from the Production of Monosodium L-glutamate

采用铁碳法、吹脱法和化学沉淀法对味精废水中离交废水的预处理进行了中试和小试。结果表明 ,以铸铁屑为主的Fe C法 ,当HRT为 2h时 ,pH从 1.97升至 4 .88,可大大减少后续中和吹氨所需石灰量 ,但Fe C还原和加石灰调节 pH处理成本相差并不大 ,Fe C还原对去除COD、氨氮和提高可生化性无明显效果。pH中和至 9 5～ 10 ,鼓气量在 10 0m3/h左右 ,水温加至 55℃左右 ,经 8h ,可将原水NH+4 N从 12mg/L左右降至 4 g/L左右 ,脱除率6 5%以上。磷酸氨镁法去除废水中NH4 + N试验结果表明 ,在ω(Mg2 +)∶ω(PO4 3- )∶ω(NH4 + N) =1∶1∶1时 ,随废水 pH升高 ,NH4 + N去除率逐步增大 ,pH10时去除率达 54%

Pilot scale and lab scale experiments were conducted to pretreat the ion exchange wastewater (the main part of the monosodium L glutamate (MSG) wastewater) by means of Fe C deoxidization to increase the pH and biodegradation, lime counteraction and aeration by air or chemical deposition to remove ammonia. The experiment results showed that, Fe C deoxidization by use of cast iron bits can increase the pH from 1.97 to 4 88, when the HRT was 2h so that the lime quantity for ammonia removal can be reduced greatly. But there was a little difference for the cost of pH adjust by Fe C deoxidization and lime counteraction, and no obvious effects were found for the removal COD and ammonia, so does the increase of biodegradation. The influent ammonia can be reduced from 12?g/L to 4?g/L after 8 hrs reaction, and removal rate can be above 65%, when the pH was 9 5～10; the air quantity was about 100?m 3/h; the wastewater temperature was heated to 55℃. The experiment result of ammonia removal by means of chemical deposition showed that, when ω(Mg 2+ )∶ω(PO 4 3- )∶ω(NH 4 + N)=1∶1∶1, ammonia removal rate increased with the increase of pH. When the pH was 10, the ammonia removal rate can reach 54%.