碳钢屑/活性炭混合反应器对焦化废水的预处理

研究了碳钢屑/活性炭混合床反应器对焦化废水中COD的去除效果及其影响因素,并依据腐蚀电化学原理对机理作了探讨。结果表明,碳钢屑/活性炭混合床反应器可以有效地去除焦化废水中的COD,其去除率能达到80%左右;在2 h左右的反应时间里,pH值对去除效果的影响仅为3%,加入絮凝剂可使去除率提高5%左右;碳钢屑/活性炭混合床反应器对焦化废水中COD的去除主要是通过电絮凝起作用。     

Genome assembly comparison identifies structural variants in the human genome

Numerous types of DNA variation exist, ranging from SNPs to larger structural alterations such as copy number variants (CNVs) and inversions. Alignment of DNA sequence from different sources has been used to identify SNPs and intermediate-sized variants (ISVs). However, only a small proportion of total heterogeneity is characterized, and little is known of the characteristics of most smaller-sized (<50 kb) variants. Here we show that genome assembly comparison is a robust approach for identification of all classes of genetic variation. Through comparison of two human assemblies (Celera's R27c compilation and the Build 35 reference sequence), we identified megabases of sequence (in the form of 13,534 putative non-SNP events) that were absent, inverted or polymorphic in one assembly. Database comparison and laboratory experimentation further demonstrated overlap or validation for 240 variable regions and confirmed >1.5 million SNPs. Some differences were simple insertions and deletions, but in regions containing CNVs, segmental duplication and repetitive DNA, they were more complex. Our results uncover substantial undescribed variation in humans, highlighting the need for comprehensive annotation strategies to fully interpret genome scanning and personalized sequencing projects.