Study on operational characteristics of UASB reactor with adding oyster shell powder

采用牡蛎壳粉末作为uASb反应器的辅助介质,探讨了牡蛎壳钙盐的溶出特性,系统考察了运行期中牡蛎壳粉末添加方式、进水有机负荷、水力停留时间等因素对反应器出水COd、碱度与PH的影响,分析了污泥比产甲烷活性变化。结果表明,当初始PH从5到9变化时,牡蛎壳粉末溶出CA2+浓度为40~65 Mg/l,平衡PH稳定在7.7~8.0;当进水COd负荷从3.4 kg/(M3·d)逐渐增至7.0 kg/(M3·d)、牡蛎壳粉末投加量从1.5 g/d逐渐增至3.2 g/d时,与未投加的反应器相比,投加牡蛎壳粉末反应器的启动周期缩短了10%左右,COd去除率与比产甲烷活性分别提高了13.3%和22%。投加牡蛎壳粉末可有效提供碱度,加快污泥的颗粒化进程。The operational characteristics of UASB reactor with which oyster shell powder was added as cocarrier were investigated using different parameters,such as the amount of shell powder added in reactor,organic loading in influent and hydraulic retention time.The dissolution of Ca2 +from oyster shell powder was assessed in batch experiment.The changes of COD and alkalinity in effluent as well as pH in reactor with the time were obtained and the specific methanogenic activity of the sludge was analyzed during the operation period.The results showed that the Ca2 +concentration dissolved from oyster shell powder was 40 ~ 65 mg /L and the equilibrium pH maintained at 7.7 ~ 8.0 when initial pH varied in the range of 5 ~ 9.By comparing with the control reactor,it was found that the start up time was shortened about 10% and the removal efficiency of COD and the specific methanogenic activity increased 13.3% and 22%,respectively in the shell powder added reactor,while the organic loading in influent increased gradually from 3.4 kg /( m3·d) to 7.0 kg/( m3·d) and the amount of added shell powder was raised from 1.5 g /d to 3.2 g /d.This finding suggested that the addition of oyster shell powder in UASB reactor played the important roles in supplying alkalinity and speeding up the process of granular sludge.福建省重大专项研究项目(2005YZ1023

Modification Method of Powdered Aspergillus niger in Biosorption of C. I. Direct Blue 199

分别采用甲酸+甲醛浸泡、甲醇+盐酸浸泡、丙酮浸泡、氢氧化钠浸泡、盐酸浸泡等改性方法对黑曲霉菌粉表面功能基团进行强化,以直接耐晒翠蓝fbl染料为吸附对象,通过傅里叶红外光谱仪(fT-Ir)考察浸泡处理前后吸附剂表面功能基团的结构及强度变化,探讨功能基团的强化条件。结果表明:采用盐酸+甲醇以及甲酸+甲醛浸泡处理不能提高黑曲霉菌粉的脱色能力;采用氢氧化钠浸泡处理黑曲霉菌粉的脱色能力明显提高,证明在黑曲霉吸附直接耐晒翠蓝过程中,有氨基、羟基、羧基的参与;采用盐酸浸泡处理黑曲霉菌粉表面杂质得到一定的去除,功能基团显现出来,脱色能力明显提高。The several chemical reagents, such as formic acid and formaldehyde, methanol and hydrochloric acid, acetone,sodium hydroxide, hydrochloric acid, were employed to modify the powdered Aspergillus niger, respectively, which was used for biosorption of C.I.Direct Blue 199.The structure and strength changes of functional group at the surface of powdered Aspergillus niger before and after modification were analysed by FT-IR spectrum, and the strengthen condition of the functional group was discussed.The results showed that the decolorization efficency did not changed, when the powdered Aspergillus niger were modified by hydrochloric acid and methanol, formaldehyde and formic acid, respectively.Whereas the decolorization efficency increased significantly by using the powdered Aspergillus niger modified by sodium hydroxide, implying that amino, hydroxyl, carboxyl group in the surface of powdered Aspergillus niger were involved in biosorption of C.I.Direct Blue 199.The increase in decolorization efficency was observed when the powdered Aspergillus niger were modified by hydrochloric acid, suggesting that the functional group at surface of Aspergillus niger exposed increasingly due to the removal of impurity substance at the surface of Aspergillus niger.福建省重大专项研究项目(2005YZ1023); 厦门市科技计划项目(3502Z20083001

Kinetic Study on Biosorption of C.I.Direct Blue 199 Using Powdered Aspergillus niger

采用黑曲霉(ASPErgIlluS nIgEr)菌粉为生物吸附剂,以直接耐晒翠蓝199(fbl)染料为吸附对象,系统考察了PH值、反应温度和染料质量浓度对脱色性能的影响,研究了吸附反应动力学特性.结果表明,当PH在3.0~7.0的范围、吸附平衡时间为40MIn时,吸附量达到最大的7.50~8.2Mg/g;当染料质量浓度为400Mg/l、温度从25℃升至45℃时,吸附量从18.34Mg/g增至29.96Mg/g;黑曲霉菌粉对fbl的吸附速率主要取决于化学吸附反应速率,吸附反应过程符合准二级反应动力学模型.The phthalocyanine dye C.I.Direct Blue 199,widely used the textile industry,contains a copper ion in its structure,a could possibly be removed from aqueous solution by inactive niger,which has a high adsorption ability for copper ions.However,no study has so far been focused on the biosorptability of inactive Aspergillus niger for this dye.In this study,nonviable Aspergillus niger powder was used for the biosorption of C.I.Direct Blue 199in a batch system.The major objective was to investigate the influences of pH,temperatures and initial dye concentration on the biosorption capacity,and to study the biosorption kinetics of Aspergillus niger powder.The results showed that the highest biosorption capacity of powdered Aspergillus niger for C.I.Direct Blue 199was 7.50-8.24mg/g at pH 3.0-7.0.The maximum dye uptake capacity of the biosorbent increased from 18.34mg/g to 29.96mg/g at 400mg/L dye concentration by increasing the temperature from 25℃to 45℃.Adsorption kinetics followed the pseudo-second order equation,which suggested that chemisorption significantly contributed to the adsorption process.福建省重大专项研究项目(2005YZ1023); 厦门市科技计划项目(3502Z20083001