稳定性的膨胀的颗粒状污泥床对涤纶人造丝印染废水的处理_毕业设计外文翻译(编辑修改稿)

稳定性的膨胀的颗粒状污泥床对涤纶人造丝印染废水的处理_毕业设计外文翻译(编辑修改稿)内容摘要：

became more stable. After startup, the efficiency of COD removal increased to 57 %~64 %, pH stabilized in a range of ~, and production rate of biogas was relatively high and stable. Sludge granulating, suitable influent of pH and loading were responsible for the EGSB stability. The variation of VFA concentration only resulted inneglectable rebound of pH, and the inhibition from VFA could be ignored in EGSB. The EGSB reactor was stable for TPD wastewater treatment. Keywords: expanded granular sludge bed。 stability。 anaerobic treatment。 dyeing and printing wastewater Introduction： In order to obtain pliable and elegant terylene fabric just like silk, terylene greige cloth is always pretreated with alkalideposition process, wherein terylene fiber is hydrolyzed to some extent in NaOH solution at certain temperature and pressure. During this process, the superficial terylene fibred is peeled off from the greige cloth and dissolved into solution, in which terylene acid (TA) and ethylene glycol are discharged as the main pollutants in 13 wastewater. The obtained terylene fabric with silken wrinkle and soft feeling is called artificial silk fabric. The alkalideposition of terylene can be described by the chemical equation below. The wastewater from the alkalideposition process mixed with wastewater from printing, dyeing, potch and the other processes is named terylene artificial silk printing and dyeing wastewater ( T/Dwastewater ) . Only in Shaoxing County, East China, are there more than 300 thousands tons TPDwastewater discharged each day. Although the anoxic or aerobic bioprocess has been the usual approach for the treatment of such kind of wastewater, various anaerobic process configurations were also found their usage in this field. However, the widespread application of anaerobic process has been hampered by the lack of understanding of factors associated with stability of the biological processes involved. The removal efficiency of anic substrates , the biogas production rate and the other items , which are involved in the stability of the process , depends on the acidbase balance. The characteristic pollutant TA in the TPDwastewater is a kind of dualanic acid , which exists in water in the form of molecule or ion state. It is still vague about the effect of TA to the acidbase balance in anaerobic system. The expanded granular sludge bed ( EGSB) process developed from UASB process , is one of the controlled anaerobic treatment processes with advantages of higher rate and better toxic resistance. Although EGSB process has the efficiency of % % for chemical oxygen demand ( COD) removal and % % for TA removal (Guan , 2020) , further development of EGSB technology for TPDwastewater treatment depends upon a better understanding of the process stability. In this paper , the stability of the 14 process was discussed , the acidbase balance was emphasized and lab scale experiments were conducted. 1 Experimental Wastewater and activated sludge The wastewater in the experiment was taken from the central pump station for 3 605 t/d TPD wastewater in Shaoxing County , Zhejiang Province , China. After a oneyear round survey , the main pollutants in the wastewater are given in Table 11 TPD wastewater characterized by high pH , COD value and color (COL) is different from traditional printing and dyeing wastewater. The value of COD varies from 780 mg/L to 3116 mg/L。 and biological oxygen demand for 5 d (BOD5 ) from 325 mg/L to 1436 mg/L. TA ranging from 286 Mg/L to 1279 mg/L is the characteristic pollutant controlling 40 % 68 % of the total COD in TPD wastewater. Activated sludge for the experiment was obtained from the treatment facility for pesticide wastewater , printing and dyeing wastewater and phenol wastewater. Sludge was acclimated firstly in a laboratory anaerobic reactor running in a fill and drawn mode under the same conditions as EGSB reactor to retain high concentration of biomass. Experimental setup and process The columned EGSB reactor was divided into four partments (Fig. 2) : (1) the granular sludge bed in which the granulated sludge was accumulated。 ( 2) the fluidized zone in which sludge was suspended。 (3) the gasliquid sludge separator。 and (4) the setting zone. The influent and reflux from the recycle pump was pumped into the bottom of the reactor and passed through the granular sludge bed. Above the granular sludge bed , a fluidized zone developed mainly due to wastewater recycle. In the granular sludge bed and fluidized zone , the biological degradation took place and the biogas was produced. As mixed liquor passed through the gasliquidsolid separator , the sludge with good setting abilities settled back through the apertures of the separator to the fluidized zone and sludge bed , while some flocculated and dispersed sludge was washed out 15 of the reactor with effluent , the effluent flowed into the storage vessel from the weir , and biogas flowed into a wet gas flow meter. The reactor ( Fig. 2) is meter high with fluidized zone and sludge bed f100 6 , effective cubage of L and a setting partment of L. A schematic drawing of the experimental setup is shown in Fig. 31 In order to eliminate the inhibition from high pH and shortage of N and P , the feeding wastewater was first adjusted to the concentration of COD:N:P = 200:5:1 in wastewater reservoir by adding dipotassium hydrogen phosphate and ammonia sulfate and pH = by adding dilute hydrochloric acid in a neutralization reactor controlled by titrator. A pump was used to supply wastewater continuously to EGSB reactor charged with mixed accumulated sludge capable of carbon degradation. Reaction temperature was controlled with a heater and a temperature controller. The pH was monitored and adjusted with a titrator (DL55 ,。