调理剂改善污泥脱水性能的比较研究

发布时间：2018-10-14 16:45

【摘要】：随着经济的快速发展,污水处理厂的规模越来越大,污泥产量也在与日俱增,由于污泥的成分复杂,含水量巨大,污泥的处理处置成为一个重要的环境问题。钢铁行业的迅速发展产生了大量的酸洗废液(Waste Pickling Liquor,WPL),废液中含有丰富的废酸以及一些金属等物质,一旦处理不当就会严重污染环境,同时也是对资源的一种极大浪费。本文旨在利用WPL对污泥进行调理,既实现了WPL的资源化利用,又能够解决污泥处理的难题,达到以废治废的目的。实验将WPL作为药剂用于提高污泥的脱水性能,同时将聚丙烯酰胺(Polyacrylamide,PAM)、FeCl3、AlCl3、聚合氯化铝(Poly Aluminium Chloride,PAC)用于污泥调理,以污泥比阻(Specific Resistance to Filtration,SRF)、毛细吸水时间(Capillary Suction Time,CST)、泥饼含水率、污泥脱水率作为评价指标,比较研究了单独调理和联合调理对污泥脱水性能的影响,阐述了各自的作用机理,并对最佳条件下的污泥沉降性能、絮体形貌进行分析,进行效益分析。主要方法与结果如下:(1)用PAM药剂单独调理污泥,对PAM分子量、浓度、种类进行筛选,发现分子量为1200万、质量分数0.1%的阳离子聚丙烯酰胺(Cationic polyacrylamide,CPAM)比阻SRF最小,对污泥调理效果最好。CPAM在70 mg/L时有最佳投加量,最大程度提升了污泥脱水性能。用FeCl3、AlCl3、PAC、WPL单独调理污泥,投加量分别为3.5 g/L、4 g/L、6 g/L、7 g/L时污泥各项评价指标基本达到最好,明显改善污泥脱水性能。(2)在单一药剂对污泥调理的基础上,以CPAM和FeCl3、AlCl3、PAC对污泥的联合调理为对照,研究了CPAM和WPL联合调理时投加量、投加顺序等因素对污泥脱水效果的影响,并进行正交验证,证明了药剂联合调理时的效果要优于各自的单独调理,投加顺序对污泥脱水性能影响较大。CPAM与FeCl3联合调理污泥,在投加量分别为50 mg/L、1.5 g/L时脱水性能最好;CPAM与Al Cl3联合调理污泥,在投加量分别为60 mg/L、1.0 g/L时脱水性能最好;CPAM与PAC联合调理污泥,在投加量分别为60mg/L、1.0 g/L时脱水性能最好;CPAM与WPL联合调理污泥时,在投加量分别为60 mg/L、1.1g/L时脱水性能最好,各项评价指标最优,污泥改善率最高。CPAM与其它药剂联合调理污泥时,先投加药剂,再投加CPAM的投加顺序能够使污泥改善率更大,脱水效果更好。(3)将原污泥、最佳条件下的CPAM以及各个药剂联合调理的结果做污泥沉降性能、絮体形貌分析,发现污泥经CPAM调理后沉降性能明显提高,絮体结构较稳定,脱水性能较好;经联合调理后的污泥更易沉降,絮体更加致密稳定,脱水性能得到进一步提高;WPL与CPAM联合调理具有良好的经济效益和环境效益。综合上述研究成果,通过酸洗废液和其它药剂对污泥的调理研究比较,认为将酸洗废液应用于污泥调理是可行且有效的,能够一定程度的实现污泥与酸洗废液的可利用化和资源化。
[Abstract]:With the rapid development of economy, the scale of sewage treatment plant is becoming larger and larger, and the sludge output is also increasing. Because of the complex composition of sludge and huge water content, sludge treatment and disposal has become an important environmental problem. The rapid development of iron and steel industry has produced a large number of acid pickling waste liquid (Waste Pickling Liquor,WPL). The waste liquid contains abundant waste acid and some metal substances. Once the treatment is improper, it will seriously pollute the environment, and it is also a great waste of resources. The purpose of this paper is to use WPL to regulate sludge, which not only realizes the resource utilization of WPL, but also solves the problem of sludge treatment, and achieves the purpose of treating waste with waste. WPL was used as agent to improve sludge dewatering performance. Polyacrylamide (Polyacrylamide,PAM) and FeCl3,AlCl3, polyaluminum chloride (Poly Aluminium Chloride,PAC) were used in sludge conditioning, sludge specific resistance (Specific Resistance to Filtration,SRF), capillary water absorption time (Capillary Suction Time,CST), mud cake moisture content. Sludge dewatering rate was used as evaluation index. The effects of single conditioning and combined conditioning on sludge dewatering performance were compared and studied. The mechanism of sludge dewatering was discussed. The sludge settling performance and floc morphology under optimum conditions were analyzed. Carry out benefit analysis. The main methods and results are as follows: (1) the molecular weight, concentration and type of PAM were screened by using PAM reagent to treat sludge alone. The results showed that the specific resistance of cationic polyacrylamide (Cationic polyacrylamide,CPAM) with molecular weight of 12 million and 0.1% of mass fraction was the smallest. The optimum dosage of CPAM was 70 mg/L, and the sludge dewatering performance was greatly improved. When the sludge was treated with FeCl3,AlCl3,PAC,WPL alone and the dosage was 3.5g / L ~ 4 g / L ~ (-1) / L ~ (6) g / L ~ (7) g 路L ~ (-1) 路L ~ (-1) ~ (-1), the sludge dewatering performance was improved obviously. (2) on the basis of the sludge conditioning by a single agent, The effects of the dosage and sequence of CPAM and WPL on sludge dewatering were studied by using the combined conditioning of CPAM and FeCl3,AlCl3,PAC as the control, and the orthogonal test was carried out. The results show that the effect of combined conditioning is better than that of their individual conditioning, and the addition order has a great influence on sludge dewatering performance. When the dosage of CPAM and FeCl3 is 50 mg/L,1.5 / L, the dewatering performance of sludge is the best, and that of CPAM and Al Cl3 is the best. When the dosage is 60 mg/L,1.0 / L, the dehydration performance is the best; when the dosage of CPAM and PAC is 60 mg / L, the dehydration performance is the best; when the dosage is 60 mg / L, respectively, the dehydration performance is the best; when the dosage of CPAM and WPL is 60 mg/L,1.1g/L, the dehydration performance is the best. When the sludge was treated with CPAM and other chemicals, the sludge improvement rate was the highest and the sludge improvement rate was the highest. (3) when the sludge was treated with CPAM and other chemicals, the sludge improvement rate was greater and the dewatering effect was better. The results of CPAM and combined conditioning of various agents under the optimum conditions were used to analyze the sedimentation performance of sludge and the morphology of flocs. It was found that the settling performance of sludge was obviously improved after CPAM conditioning, the flocs structure was stable, and the dehydration performance was better. The sludge can be settled more easily, the flocs are more compact and stable, the dehydration performance is further improved, and the combined treatment of WPL and CPAM has good economic and environmental benefits. Based on the above research results, it is considered that it is feasible and effective to apply acid pickling waste liquid to sludge conditioning by comparing the treatment of sludge with acid pickling waste liquid and other chemicals. It can realize the utilization and resource of sludge and pickling liquid to a certain extent.
【学位授予单位】：陕西科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X703

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