TiO_2/活性炭光催化技术在印染废水深度处理中的应用研究

通过TiO2／活性炭光催化剂的光催化氧化作用,对印染废水的生化处理出水进行深度处理。实验考察了pH值、催化剂负载次数、光照时间、催化剂投加量等因素对处理效果的影响。实验结果表明：催化剂负载次数为4次,光照时间30min,催化剂投加量为3g时,处理效果最佳。此时出水COD达到50mg／L,色度为2,达到印染行业回用水的标准。     

混凝法处理有机氯农药废水的研究

以有机氯农药废水为研究对象 ,研究了无机混凝剂PAC及其与有机高分子混凝剂PAM (J 3450 ,J 1 1 50 )复合使用的混凝处理特性。通过正交实验确定了混凝反应各种影响因子的最佳操作条件。在此条件下 ,水质 1、2的COD去除率分别为 38%、40 .6 % ;色度去除率分别为 98% ,2 0 %。混凝处理后 2种水质的B/C值也得到了提高。在各影响因子与COD去除率的关系曲线基础上 ,分析了废水中各影响因子的作用机理。     

Kinetics of phenol and m-cresol biodegradation by an indigenous mixed microbial culture isolated from a sewage treatment plant

An acclimatized mixed microbial culture, predominantly Pseudomonas sp., was enriched from a sewage treatment plant, and its potential to simultaneously degrade mixtures of phenol and m-cresol was investigated during its growth in batch shake flasks. A 2² full factorial design with the two substrates at two different levels and different initial concentration ranges (low and high), was employed to carry out the biodegradation experiments. The substrates phenol and m-cresol were completely utilized within 21 h when present at low concentrations of 100 mg/L for each, and at high concentration of 600 mg/L for each, a maximum time of 187 h was observed for their removal. The biodegradation results also showed that the presence of phenol in low concentration range (100–300 mg/L) did not inhibit m-cresol biodegradation. Whereas the presence of m-cresol inhibited phenol biodegradation by the culture. Moreover, irrespective of the concentrations used, phenol was degraded preferentially and earlier than m-cresol. A sum kinetics model was used to describe the variation in the substrate specific degradation rates, which gave a high coefficient of determination value (R² > 0.98) at the low concentration range of the substrates. From the estimated interaction parameter values obtained from this model, the inhibitory effect of phenol on m-cresol degradation by the culture was found to be more pronounced compared to that of m-cresol on phenol. This study showed a good potential of the indigenous mixed culture in degrading mixed substrate of phenolics.     

Kinetics of phenol and m-cresol biodegradation by an indigenous mixed microbial culture isolated from a sewage treatment plant

An acclimatized mixed microbial culture, predominantly Pseudomonas sp., was enriched from a sewage treatment plant, and its potential to simultaneously degrade mixtures of phenol and m-cresol was investigated during its growth in batch shake flasks. A 22 full factorial design with the two substrates at two di erent levels and di erent initial concentration ranges (low and high), was employed to carry out the biodegradation experiments. The substrates phenol and m-cresol were completely utilized within 21 h when present at low concentrations of 100 mg/L for each, and at high concentration of 600 mg/L for each, a maximum time of 187 h was observed for their removal. The biodegradation results also showed that the presence of phenol in low concentration range (100–300 mg/L) did not inhibit m-cresol biodegradation. Whereas the presence of m-cresol inhibited phenol biodegradation by the culture. Moreover, irrespective of the concentrations used, phenol was degraded preferentially and earlier than m-cresol. A sum kinetics model was used to describe the variation in the substrate specific degradation rates, which gave a high coe cient of determination value (R2 > 0.98) at the low concentration range of the substrates. From the estimated interaction parameter values obtained from this model, the inhibitory e ect of phenol on m-cresol degradation by the culture was found to be more pronounced compared to that of m-cresol on phenol. This study showed a good potential of the indigenous mixed culture in degrading mixed substrate of phenolics.     

Experimental investigation of the effect of sediment transport patterns on the adsorption of cadmium ions onto sediment particles

The mechanism of flow turbulence, sediment supply conditions, and sediment transport patterns that affect the adsorption of cadmium ions onto sediment particles in natural waters are experimentally simulated and studied in this study both in batch reactors and in a turbulence simulation tank. By changing the agitation conditions, the sediment transport in batch reactors can be categorized into bottom sediment-dominated sediment and suspended sediment-dominated sediment. It is found that the adsorption rate of bottom sediment is much less than that of suspended sediment, but the sediment transport pattern does not affect the final (equilibrium) concentration of dissolved cadmium. This result indicates that the parameters of an adsorption isotherm are the same regardless of the sediment transport pattern. In the turbulence simulation tank, the turbulence is generated by harmonic grid-stirred motions, and the turbulence intensity is quantified in terms of eddy diffusivity, which is equal to 9.84F(F is the harmonic vibration frequency) and is comparable to natural surface water conditions.When the turbulence intensity of flow is low and sediment particles stay as bottom sediment, the adsorption rate is significantly low, and the adsorption quantity compared with that of suspended sediment is negligible in the 6 h duration of the experiment. This result greatly favors the simplification of the numerical modeling of heavy metal pollutant transformation in natural rivers. When the turbulence intensity is high but bottom sediment persists, the rate and extent of descent of the dissolved cadmium concentration in the tank noticeably increase, and the time that is required to reach adsorption equilibrium also increases considerably due to the continuous exchange that occurs between the suspended sediment and the bottom sediment.A comparison of the results of the experiments in the batch reactor and those in the turbulence simulation tank reveals that the adsorption ability of the sediment, and in particular the adsorption rate, is greatly over-estimated in the batch reactor.     

煤及其燃烧产物中微量元素的淋滤试验研究

用没ＰＨ值溶液对炉前原煤、灰化灰、底灰、飞灰进行了对比淋滤试验。重点考察了Ａｓ、Ｚｎ、ＰＢ、Ｎｉ、Ｓｒ等５种元素的淋出行为。发现溶液的ＰＨ、淋滤时间,特别是元素的性质及其赋存状态对元素的淋滤难易程度有重要影响,所分析的５种元素中,Ｓｒ以强淋滤为主,Ｐｂ和Ａｓ以强淋滤和中等淋滤为主,Ｎｉ以中等淋滤为主,而Ｚｎ则为难淋滤元素。     

岩石中氟的赋存状态研究

使用逐级化学提取方法对岩石中氟的赋存状态进行了研究.结果表明:岩石中氟主要与K和Al呈显著相关,高氟岩石中氟与P呈显著正相关,氟主要以氟磷灰石的形式存在;经逐级提取后残渣中的氟与Ca呈显著负相关关系,碳酸盐岩和磷块岩中的氟主要以水溶态和碳酸盐结合态等易溶形式存在;而硅质岩、黑色页岩、硅质碳板岩和碳质板岩中的氟主要存在于难溶矿物中.     

垃圾填埋场生物覆盖材料筛选及甲烷减排

通过模拟柱实验研究了消化污泥、矿化垃圾和黏土作为垃圾填埋场生物覆盖材料的甲烷氧化能力。3种材料的甲烷日氧化率平均值、总氧化率和氧化速率V(CH4)分别是:消化污泥10.27%、75.82%、1.76 mmol/(kg·d);矿化垃圾11.05%、75.61%、2.04 mmol/(kg·d);黏土9.05%、68.15%、1.33 mmol/(kg·d),消化污泥和矿化垃圾对甲烷的氧化能力均大于黏土。进一步探讨了消化污泥中添加粉煤灰、建筑垃圾和黏土进行改性后对甲烷的氧化能力,考察了改性污泥的渗透系数和抗压强度。结果表明:粉煤灰对消化污泥的改性效果最好,其日氧化率平均值、总氧化率和V(CH4)分别达到17.27%、92.37%和2.35 mmol/(kg·d),粉煤灰与消化污泥以1∶1～1.5∶1混配后可满足填埋场对覆盖材料渗透系数和抗压强度的要求。     

粉煤灰对重金属钼的吸附效果及其影响因素

为了探讨粉煤灰对重金属钼的吸附影响因素及吸附机理,以粉煤灰为吸附剂,钼酸铵为吸附质,通过单因子试验分别考察粉煤灰粒径、粉煤灰投加量、吸附时间、pH和温度等因素对吸附效果的影响,确定了粉煤灰吸附的最佳条件(粒径为80~100目,投加量为2.5 g,吸附时间为30 min,pH为3,温度为30 ℃)。在此条件下,粉煤灰对钼酸铵的去除率达到80%~85%。分别用纯水以及0.01,0.05,0.10 mol/L的NaOH和0.05 mol/L的NaCl对最佳吸附条件下的粉煤灰进行解吸试验,结果表明,在粉煤灰的吸附过程中,化学吸附作用大于物理吸附。     

响应曲面法优化工业高钙废水制硫酸钙晶须的工艺

以某厂毒重石制备氯化钡过程中副产的高钙废水为原料,在常压条件下制备硫酸钙晶须。首先,用少量稀硫酸对钙水进行除杂处理,然后通过正交实验对实验过程进行优化,得出较优反应条件为:高钙废水20 mL、1 mol/L硫酸用量72 mL、氯化镁用量0.75 g、反应温度108℃、反应时间3 h,搅拌强度300 r/min。经图像颗粒分析系统、数显白度仪和XRD表征,该产品为半水硫酸钙晶须,长径比55,白度为91.2%,纯度为98.7%,产率41%。用响应曲面法对工艺条件进行优化,得到的最优工艺条件和实验得到的较优条件是相近的。