Dissertation > Excellent graduate degree dissertation topics show

Study and Preparation in High Efficient Degradation Bacteria of Pahs and Biological Activated Carbon

Author: JiangLiJuan
Tutor: WangGuangHua
School: Wuhan University of Science and Technology
Course: Chemical processes
Keywords: Coking wastewater Biological activated carbon High efficiency strain advanced treatment Green technology
CLC: X703
Type: Master's thesis
Year: 2011
Downloads: 143
Quote: 0
Read: Download Dissertation

Abstract

A enormous amount of water is consumed in our steel production process, especially the coking wastewater accompanied by coking production process. Coking wastewater contains lots of polycyclic aromatic hydrocarbons (PAHs) which is harmful for environment and human health. If the coking wastewater is directly discharged into emvironment, the generated hazard will be inestimable. There are still a large gap in our per ton steel fresh water consumption and efflux, comparing with the international advanced technology. Therefore, improving steel enterprises, especially coking industry, comprehensive utilization of water resources and recycling rate of outer drainage will have important practial significance on rational use of water resources, steady and rapid economic development and harmonious development of society.There are plenty of leading to mutagenesis, carcinogenesis and teratogenesis and refractory components, PAHs, in the coking wastewater, so the key to treating coking wastewater is low energy consumption and green technologies without secondary pollution. Naphthalenes and quinolines are the highest percentage of PAHs in the coking wastewater. It play important role in coking wastewater advanced treatment and regeneration recycling utilization.Biological activated carbon (BAC) as a kind of green water treatment technology has been widely used in micro-polluted water and industrial wastewater treatment, but rarely reported in coking wastewater advanced treatment and regeneration recycling utilization. This research is based on BAC technology characteristic, studying in naphthalene and isoquioline biodegradability, BAC’s practicality, feasibility and superiority in coking wastewater advanced treatment technology and providing theoretical basis for the follow-up research and coking wastewater recycling utilization.Research results show that: (1)The experiment successfully has separated high efficiency degradation strains (HES) respectively named N-3 and K-4 as naphthalene or isoquinoline the unique substrate from the coking plant and aeration tank activated sludge through enrichment, domestication and purification. The high efficiency degradation strains provide with microorganism in the following BAC experiments. (2)According to the HES N-3 physiology and biochemistry 16Sr DNA sequence analysis experiment result, the strain N-3 is identified as Bacillus subtilis, which GenBank sequence number is AEHM01000002.1. (3)Accoeding to the HES K-4 physiology and biochemistry experiment result, the strain K-4 is initially identified as Pseudomonas. (4)The HES, GAC-3 and BAC are respectively applied to ttreating sedimentation tank effluent of coking process. After treatment for 72h, the removal rate of COD by BAC was 17.80% higher than GAC-3 and 61.61% higher than HES; the removal rate of chromaticity by BAC was 2.2% higher than GAC-3 and 89.41% higher than HES. The treated water by BAC can reach the renewable water stanedard. After reduplicative treatments for 15 times, the average removal rate of COD by BAC was 11.90% higher than GAC-3 and 86.08% higher than HES; the average removal rate of chromaticity by BAC was 26.6% higher than GAC-3 and 79.02% higher than HES. The BAC showed the superiority and feasibility in coking wastewater advanced and regeneration recycling treatment. (5)The BAC device jointly researched and produced by HES and GAC-3 had a good removal rate of organic matter in simulated wastewater, steadily around at 60%. (6)The high efficiency degradation microbe on the BAC was circularly pumped though high mixed efficiency bacteria and nutritive water, uniformly and closely attached and grew on the carbon surface and formed the degrading biomembrane. The biomass on the BAC is lower along with higher carbon layer. The BAC device final effluent OD value increased at first then decreased, stabilized at last. The BAC adsorbed and biodegraded the organic matter in simulated wastewater kinetic model fit first level kinetic model,InC=-0.0318t+6.0143.

Related Dissertations

CLC: > Environmental science, safety science > Processing and comprehensive utilization of waste > General issues > Wastewater treatment and utilization
© 2012 www.DissertationTopic.Net Mobile