酸性凝聚——过氧化氢氧化法处理染色废水

印染废水的特点是COD、BOD和色度等均较高。COD、色度一般适于用活性炭吸附、氯氧化、臭氧氧化、反渗透等物化法处理,但这些方法处理成本都较高。本文所述酸性凝聚-过氧化氢氧化联合处理新工艺能有效地去除染色废水中难生化降解的有机物和色度,方法简便,处理成本低,处理效果好。

Study on coagulation property of metal-polysilicate coagulants in low turbidity water treatment

In order to remove the low turbidity present in surface water, a novel metal-polysilicate coagulant was used to treat the raw water taken from Tanjiang River in Guangdong Province. This study on the effects of Al/Fe molar ratio on the performance of a complex compound formed by polysilicic acid, aluminium and ferric salt (PAFS) showed that PAFS with Al/Fe ratio of 10:3 seemed to have the best coagulation performance in removing turbidity and color. Experimental results showed that under the conditions of polymerization time of 15 d, sedimentation time of 12 min, and pH of 6?8, PAFS with Al/Fe molar ratio of 10:3 had the best coagulation efficiency and lowest residual Al concentration. The turbid- ity decreased from 23.8 NTU to 3.23 NTU and the residual Al concentration was only 0.165 mg/L in the product water. It could be speculated that colloidal impurities and particulate Al were removed by adsorption bridging and electrical neu- tralization of long chain inorganic polymer coagulants.

Novel biosensor-based microarray assay for detecting rs8099917 and rs12979860 genotypes

AIM:To evaluate a novel biosensor-based microarray(BBM) assay for detecting rs12979860 and rs8099917 genotypes.METHODS:Four probes specific for rs8099917C/T or rs12979860G/T detection and three sets of quality control probes were designed,constructed and arrayed on an optical biosensor to develop a microarray assay.Two sets of primers were used in a one tube polymerase chain reaction(PCR) system to amplify two target fragments simultaneously.The biosensor microarray contained probes that had been sequenced to confirm that they included the rs8099917C/T or rs12979860G/T alleles of interest and could serve as the specific assay standards.In addition to rehybridization of four probes of known sequence,a total of 40 clinical samples collected from hepatitis C seropositive patients were also tested.The target fragments of all 40 samples were amplified in a 50 μL PCR system.Ten μL of each amplicon was tested by BBM assay,and another 40 μL was used for sequencing.The agreement of the results obtained by the two methods was tested statistically using the kappa coefficient.The sensitivity of the BBM assay was evaluated using serial dilutions of ten clinical blood samples containing 10 3-10 4 white cells/μL.RESULTS:As shown by polyacrylamide gel electrophoresis,two target segments of the interleukin 28Bassociated polymorphisms(SNPs) were successfully amplified in the one-tube PCR system.The lengths of the two amplified fragments were consistent with the known length of the target sequences,137 and 159 bps.After hybridization of the PCR amplicons with the probes located on the BBM array,the signals of each allele of both the rs8099917 SNPs and rs12979860 SNPs were observed simultaneously and were clearly visible by the unaided eye.The signals were distinct from each other,could be interpreted visually,and accurately recorded using an ordinary digital camera.To evaluate the specificity of the assay,both the plasmids and clinical samples were applied to the microarray.First,30 PCR amplicons of the various SNP alleles were hybridized on the BBM microarray.Full agreement between plasmids and the BBM assay was observed,with 30/30 correct matches(100%).The kappa value for the BBM assay with plasmids was 1.00(P < 0.05).For the 40 clinical blood samples,the BBM assay hybridization and direct sequencing results were compared for each amplicon.For patient blood samples,agreement was 28/28 for rs8099917T/T,9/11 for rs8099917T/G,1/1 for rs8099917G/G,24/24 for rs12979860C/C,11/14 for rs12979860C/T,and 2/2 for rs12979860T/T.Only five clinical samples of amplicon assay and direct sequencing results were discordant and heterozygotes:2/11 rs8099917T/G and 3/14 rs12979860C/T.The agreement of outcomes between BBM assay and direct sequencing for the detection of rs8099917 and rs12979860 was 95% and 92.5%,respectively;and the corresponding kappa values were 0.88 and 0.85(A kappa value > 0.75 was defined as substantial agreement).The BBM assay and sequencing had similar specificities for detection and identification of the two SNPs and their alleles.The sensitivity evaluation showed that the BBM assay could detect and identify SNP sequences present in blood samples containing as few as 10 2 white blood cells/μL.CONCLUSION:This biosensor microarray assay was highly specific,sensitive,rapid and easy to perform.It is compatible with clinical practice for detection of rs8099917 and rs12979860.

Rheological Properties of Recycled Aggregate Concrete Using Superplasticizers

The mechanical properties of recycled aggregates concrete from demolition have been studied for several years. It has been documented that rheological properties of these concrete are generally affected by use of recycled aggregates. They could present mechanical properties less affected by the presence of recycled aggregates if the initial concrete were of good quality. However, manufacturing problems, mainly attributed to the angular character of these aggregates and to the granulometry of recycled sand, limit their industrial use. The worth point of this study consists in the optimization of the concrete formulation using specific admixture, adapted to this aggregates in order to facilitate its manufacturing. It shows that the new generation of superplasticizers containing some copolymer polycarboxylate makes it possible to significantly improve the fluidity of the recycled aggregates concrete in its fresh state. The aim of this research is to control rheologica] properties of fresh recycled aggregates concrete with fine and coarse recycled aggregates to limit the negative influence of aggregates on mechanical properties of concrete.