Severe bilateral renal disease: Correlation of antenatal and autopsy findings

We report 20 infants with severe bilateral renal disease examined by prenatal ultrasound and by autopsy. In 17, the prenatal and pathologic diagnoses correlated well. Although the prenatal and autopsy findings differed in the three remaining cases, the autopsy confirmed the presence of severe bilateral renal abnormalities. All 20 pregnancies were complicated by oligohydramnios, which was severe in 60 per cent. Most of these fetuses had malformation of other organ systems. This series supports the utility of prenatal ultrasound examinations, but emphasizes the need for postnatal evaluation of congenital renal disease including pathologic examination of tissue when possible for correct classification and genetic counselling.     

声化学氧化－间歇式活性污泥法处理染料废水的研究

介绍了声化学氧化反应机理。采用声化学氧化法作预处理，可使生物难降解的靛兰染料废水的ＢＯＤ＿５／ＣＯＤ由０．２１—０．２３提高到０．４４—０．５１，再经间歇式活性污泥法处理后，各项水质指标均符合ＧＢ８９７８—８８《污水综合排放标准》。     

超声热效应下型煤中气体解吸规律实验研究

为了研究超声热效应对于气体解吸的影响规律,利用自行研制的具备施加超声功能的吸附解吸装置,对吸附饱和氮气的型煤试件开展超声热效应下的气体解吸试验。利用试验数据,拟合出了不同氮气压力下超声热效应作用过程中温度变化方程,解吸量方程及解吸速率方程。同时,对解吸量方程和解吸速率方程进行了试验数据验证。结果表明:超声热效应作用能够有效地提高型煤试样的温度,提高氮气的解吸130.9%-145.8%。验证结果相对误差集中在5%以内,拟合方程能够反映出超声热效应作用过程中解吸量及解吸速率的变化情况。     

Effects of different sludge disintegration methods on sludge moisture distribution and dewatering performance

A key step in sludge treatment is sludge dewatering. However, activated sludge is generally very difficult to be dewatered. Sludge dewatering performance is largely affected by the sludge moisture distribution. Sludge disintegration can destroy the sludge structure and cell wall, so as change the sludge floc structure and moisture distribution, thus affecting the dewatering performance of sludge. In this article, the disintegration methods were ultrasound treatment, K2 Fe O4oxidation and KMn O4 oxidation. The degree of disintegration(DDCOD), sludge moisture distribution and the final water content of sludge cake after centrifuging were measured. Results showed that three disintegration methods were all effective, and K2 Fe O4oxidation was more efficient than KMn O4 oxidation. The content of free water increased obviously with K2 Fe O4and KMn O4 oxidations, while it decreased with ultrasound treatment. The changes of free water and interstitial water were in the opposite trend. The content of bounding water decreased with K2 Fe O4oxidation, and increased slightly with KMn O4 oxidation, while it increased obviously with ultrasound treatment. The water content of sludge cake after centrifuging decreased with K2 Fe O4oxidation, and did not changed with KMn O4 oxidation, but increased obviously with ultrasound treatment. In summary, ultrasound treatment deteriorated the sludge dewaterability, while K2 Fe O4and KMn O4 oxidation improved the sludge dewaterability.     

Impact of ozone assisted ultrasonication pre-treatment on anaerobic digestibility of sewage sludge

Impact of ultrasonication(ULS) and ultrasonication–ozonation(ULS-Ozone) pre-treatment on the anaerobic digestibility of sewage sludge was investigated with semi-continuous anaerobic reactors at solid retention time(SRT) of 10 and 20 days. The control, ULS and ULS-Ozone reactors produced 256, 309 and 348 m L biogas/g CODfedand the volatile solid(VS) removals were 35.6%, 38.3% and 42.1%, respectively at SRT of 10 days. At SRT of20 days, the biogas yields reached 313, 337 and 393 m L biogas/g CODfedand the VS removal rates were 37.3%, 40.9% and 45.3% in the control, ULS and ULS-Ozone reactors, respectively.ULS-Ozone pre-treatment increased the residual organic amount in the digested sludge.These soluble residual organics were found to contain macromolecules with molecular weights(MW) larger than 500 k Da and smaller polymeric products with MW around 19.4and 7.7 k Da. These compounds were further characterized to be humic acid-like substances with fluorescent spectroscopy analysis.