Purification, characterization and application of dual coagulants containing chitosan and different Al species in coagulation and ultrafiltration process

The objective of this study was to investigate the effect of different Al species and chitosan (CS) dosages on coagulation performance, floc characteristics (floc sizes, strength and regrowth ability and fractal dimension) and membrane resistance in a coagulation–ultrafiltration hybrid process. Results showed that different Al species combined with humic acid in diverse ways. Al_a had better removal efficiency, as determined by UV₂₅₄ and dissolved organic carbon, which could be further improved by the addition of CS. In addition, the optimal dosage of different Al species was determined to be 4.0 mg/L with the CS concentration of 1.0 mg/L, by orthogonal coagulation experiments. Combining Al_a/Al_b/Al_c with CS resulted in larger flocs, higher recovery, and higher fractal dimension values corresponding to denser flocs; in particular, the floc size at the steady state stage was four times larger than that obtained with Al species coagulants alone. The results of ultrafiltration experiments indicated that the external fouling percentage was significantly higher than that of internal fouling, at around 85% and 15%, respectively. In addition, the total membrane resistance was significantly decreased due to CS addition.     

加压酸浸法提取粉煤灰中的Al2O3和Fe2O3

采用加压酸浸法提取粉煤灰中的A12O3和Fe2O3.实验研究了粉煤灰粒径、硫酸质量分数、反应时间、反应温度对粉煤灰中Al2O3和Fe2O3浸取率的影响,并通过SEM对粉煤灰酸浸前后的形貌进行了分析.实验结果表明,当粉煤灰粒径为75μm、硫酸质量分数为50％、反应温度为180℃、反应时间为4h时,粉煤灰中的Al2O3浸取率可达82.4％,Fe2O3浸取率为76.1％,经酸浸后粉煤灰的剩余率为72.4％.     

Detection and Characterization of Avastrovirus Associated with Diarrhea Isolated from Minks in China

Astroviruses are becoming a growing concern in veterinary and public health. Many astrovirus species are associated with enteric diseases have been described in both mammalian and avian hosts. In the present study, 23 fecal samples from diarrheic minks were collected in Liaoning and Shandong Province, and an investigation of astrovirus was performed using biochemical methods and RT-PCR assay with specific primers. A total of four mink astroviral isolates were detected from sick minks with diarrhea problems. Further sequencing and characterization of the partial ORF1b gene and ORF2 gene segments revealed low sequence identities (20.0–85.3 and 31.8–87.2 %) with known astroviral strains, indicating the emergence of a novel clade of astroviruses. Some new features of the astroviral genome have also been discovered. The phylogenetic tree revealed that all samples were distantly related to mink astrovirus and were closely related to chicken astroviruses and turkey astroviruses. MK/DL-1, MK/DL-2, MK/SD-1, and MK/SD-2 formed a new clade and were found to be more closely related to astroviruses from birds than to other mink strains, indicating past cross-species transmission and considerable zoonotic potential.     

锅炉应用旋风除尘器除尘的影响因素分析

通过对旋风除尘器结构和运行原理的分析,找出锅炉应用旋风除尘器除尘效果不佳的影响因素,提出了锅炉应用旋风除尘器提高除尘效率的措施.     

新型污水处理系统的构成及应用

介绍了美国REDFOX公司生产的新型污水处理系统的结构和原理，系统很好地解决了野外施工现场生活污水处理过程中存在的问题。     

淄博市重点工业行业VOCs排放特征

为研究淄博市重点工业行业的VOCs排放特征,筛选出9个重点行业,选择各行业代表性企业进行实地调研和采样,分析了不同行业的VOCs排放特征,通过实测法计算了各企业的VOCs排放量,并在此基础上得到本地化排放因子.结果表明,不同行业的VOCs排放特征存在一定差异,多数行业以烷烃、卤代烃为主;乙烷、乙炔、氯乙烷类(包括1,1-二氯乙烷、 1,1,1-三氯乙烷)以及氟利昂类(氟利昂12或氟利昂114)为大多数行业均含有的主要特征物种;分环节排放量计算结果显示,设备动静密封点泄漏、有机液体装卸挥发损失、有机液体储存与调和挥发损失以及工艺有组织排放为不同类型石化行业的VOCs主要排放环节,排放量占比均达到40%以上;合成橡胶与炼钢行业的VOCs本地化排放因子与已有规范中的推荐值相近,其余行业则存在较大差距.     

应用多导流筒气升式环流生物反应器处理化肥工业含氨废水

在天津××化工厂建立了一套反应器有效体积为80m3的低高径比、多导流筒气升式环流生物反应器处理化肥工业含氨废水的装置。针对影响生物硝化效果的影响因素气液比、水力停留时间进行了考察,得到了操作的优化条件气液比为50∶1,水力停留时间为5h。在此条件下,该装置对废水中的COD_(Cr)和NH4+-N的去除率分别在75%和98%以上,出水中COD_(Cr)<50mg/L,NH4+-N<10mg/L。     

低负荷间歇运行燃煤锅炉烟尘排放规律的探讨

通过对不同负荷情况下运行的燃煤锅炉烟尘排放浓度测试，探讨了低负荷间歇运行燃煤锅炉的烟尘排放规律。随着锅炉负荷的降低，过量空气系数变大，烟尘排放浓度和排放量也变大。在相近低负荷条件下运行的不同出力的锅炉，额定出力大的锅炉烟尘排放量大。在燃煤量相近而在不同负荷状态下运行的两台锅炉，额定出力大的锅炉烟尘排放量大。对于常年低负荷运行时的锅炉，环境管理部门在对其烟尘排放进行监督管理时宜以低负荷运行时的烟尘测试数据为依据。     

大尺度区域非点源污染负荷估算方法研究的意义、难点和关键技术——代“大尺度区域非点源污染研究”专栏序言

科学、规范的规划可以有效地协调人类、环境和社会之间的和谐关系,大尺度区域非点源污染负荷调查是很多规划工作的重要基础.针对当前非点源污染负荷估算方法的不足和困难,以全国水资源规划为契机,从水质水量结合的角度阐述了规划层次的大尺度区域非点源污染负荷估算方法的意义、用途和关键技术.