Reduction of dissolved organic matter in terms of DOC, UV-254, SUVA and THMFP in industrial estate wastewater treated by stabilization ponds

The aim of this research was to monitor the influent and effluent water quality of the aeration, facultative and oxidation water treatment ponds of an industrial estate. This industrial estate, the largest in northern Thailand, has proposed to utilization of reclaimed treated wastewater in their raw water supply so as to cope with the yearly water shortage during the dry season. Water samples were collected four times from four sampling points and evaluated for their dissolved organic matter (DOM) content in terms of dissolved organic carbon (DOC), ultraviolet light absorbance at 254 nm (UV-254), specific ultraviolet absorption (SUVA), trihalomethane formation potential (THMFP) and trihalomethane (THM) species. Average values of DOC, UV-254, SUVA and THMFP in the influent wastewater of 12.9 mg L⁻¹, 0.165 cm⁻¹, 1.29 L mg⁻¹m⁻¹ and 1.24 mg L⁻¹, respectively, were observed. The aeration ponds produced the best results: a 54% reduction of DOC, a 33% reduction of UV-254, and a 57% reduction of THMFP. However, SUVA in the aeration pond effluent showed a moderate increase. The facultative ponds and oxidation ponds did not take part in the reduction of DOC, UV-254, SUVA and THMFP. Average DOC, UV-254, SUVA and THMFP value of the treated wastewater were 5.8 mg L⁻¹, 0.107 cm⁻¹, 1.85 L mg⁻¹m⁻¹ and 468 μg L⁻¹, respectively. Chloroform, at 72.6% of total THMFP, was found to be the predominant THM species.     

房地产开发地铁振动达标距离研究

已建和待建的多条地铁线路穿过某房地产开发地块,为了防治地铁运行对建筑造成振动环境影响,需要设定建筑靠近地铁的最小达标距离,包括采取减振措施后的距离。通过现场系统实验监测结合数值模型分析,从工程实践的角度提出了上述距离。对于实验中观察到随距离出现振动局部放大以及进口与国产仪器监测结果不同的现象,佐证了有关学者的理论与实验分析,提出:(1)现有地铁环境影响评价报告常用的60m评价范围偏小,推荐可扩大至80~100m;(2)迫切需要新的振动环境标准发布,避免有关项目的环境管理要求偏低。     

pH、盐度对微生物还原硫酸盐的影响研究

采用厌氧生物处理工艺,研究了在不同盐度下pH连续降低对硫酸盐还原和有机物去除率的影响。实验结果表明,硫酸盐还原菌有很强的适应pH变化的能力,在pH值达到4以下仍有60％的硫酸盐去除率。NaCl浓度由4g／L增加到50g／L抑制了各厌氧菌的活性,导致硫酸盐和有机物去除率的下降,但硫酸盐还原菌耐受性高于产甲烷菌等其他厌氧菌,在NaCl浓度为50g／L下,硫酸盐去除率能达到50％,而有机物去除率则低于30％。qRT—PCR表明了系统菌落中SRB随着环境的变化情况与化学指标结果相一致,该反应器体系中SRB在整个厌氧菌群落中只占了很小部分。     

自然资源利用权的双重物权属性及环境保护价值

自然资源利用权从产生的途径上看应属于特许物权,从内容和功能上看应属于准用益物权,两种物权属性并不相互排斥。自然资源利用权的双重物权属性符合环境保护的价值取向和价值选择。     

Swine wastewater treatment in a two stage sequencing batch reactor using real‐time control

Abstract

A laboratory scale two‐stage sequencing batch reactor (TSSBR) was used to study the effectiveness of pH as a real‐time control parameter in swine wastewater treatment. A Ringlace media was inserted into the A/O (Anoxic/Oxic) reactor for bacteria immobilization. The TSSBR was subjected to three levels of organic loading. The pH and ORP (Oxidation Reduction Potential) patterns obtained were consistent with distinct features, enabling the real‐time control strategy to effectively set a flexible aeration time pending on influent concentration, hence resulting in flexible cycle time and HRT (Hydraulic Retention Time) for the system. The real‐time process ensured a removal efficiency of over 99% and 95%, respectively, for ammonia and TOC (Total Organic Carbon). For NO₃ ^‐‐N and PO₄ ^‐3, the run with influent TOC = 4,000 mg/L yielded the most efficient removal of 61% and 95%, respectively. Test results suggest that pH can be a viable tool for on‐line real‐time control of a biological treatment process.     

VFAs、TOC及COD作为生物除磷能力指标的探讨

在实际生活污水的处理中,研究了通过A/O运行模式对生物除磷过程中磷的变化情况及在厌氧释磷过程中COD、TOC与VFAs变化之间的关系。结果表明,在厌氧释磷过程中VFAs的变化更能准确地反映系统内释磷进程,实际生活污水中能直接用于磷释放的有机物含量占COD的13.33%,并且释放1 mg P所需VFAs为1.401 mg,此值明显低于前期研究结果。通过对COD、TOC和VFAs 3种组分的分析,可将实际生活污水中的有机底物分为3类:易生物降解含碳有机物、难降解的含碳有机物和水中存在的无机性还原物质,含量分别占COD的13.33%、31.7%和54.97%,其中只有13.33%的含量对生物释磷有直接作用,并可对实际生活污水除磷有指导意义。     

空气质量AQI实时发布的改进探讨

针对《环境空气质量指数(AQI)技术规定(试行)》(HJ 633-2012)中对空气质量AQI实时发布存在的欠缺,从增加颗粒物1 h浓度的AQI分级浓度限值及颗粒物24 h滑动平均值计算方法改进着手,解决PM2.5和PM10的24 h滑动平均值实时延迟、1 h平均值代替24 h滑动平均值偏高等问题。     

Pipeline leakage detection and isolation: An integrated approach of statistical and wavelet feature extraction with multi-layer perceptron neural network (MLPNN)

Leakage diagnosis of hydrocarbon pipelines can prevent environmental and financial losses. This work proposes a novel method that not only detects the occurrence of a leakage fault, but also suggests its location and severity. The OLGA software is employed to provide the pipeline inlet pressure and outlet flow rates as the training data for the Fault Detection and Isolation (FDI) system. The FDI system is comprised of a Multi-Layer Perceptron Neural Network (MLPNN) classifier with various feature extraction methods including the statistical techniques, wavelet transform, and a fusion of both methods. Once different leakage scenarios are considered and the preprocessing methods are done, the proposed FDI system is applied to a 20-km pipeline in southern Iran (Goldkari-Binak pipeline) and a promising severity and location detectability (a correct classification rate of 92%) and a low False Alarm Rate (FAR) were achieved.     

油品真实蒸汽压多元非线性回归

油品蒸气压是从事油品蒸发损耗研究、计算油品蒸发损耗量的重要参数,但是仅有美国石油学会给出的诺模图,给利用计算机来计算储罐蒸发损耗带来了很大困难.为了利用计算机来计算储罐的蒸发损耗,运用Excel中的回归功能,对原始数据进行必要的转换,进行了真实蒸气压的多元非线性回归,回归出了油品真实蒸气压计算公式.结果显示,回归的方程具有很高的精度,利用回归方程编制了计算软件,为储罐蒸发损耗计算提供帮助.     

生态住宅的水环境规划:I. 水循环

生态住宅已成为住宅建设的发展趋势和潮流,水环境是生态住宅小区的重要组成部分。文章以中信保利达美景度假区为实例,根据度假区建筑总体规划方案,结合当地自然条件和水环境现状,探讨生态住宅小区的水环境规划,全面统一规划住宅小区内各种水系统,提出小区水环境总体规划方案,充分发挥各系统的功能,使其相互衔接、协调与补充。重点对项目所在区域开发前后的水量平衡,水库的水位变化及其安全性,极端气候条件下的库区水量变化及其因应对策,高尔夫球道的用水方案以及项目开发后的水循环模型做了深入探讨,旨在为生态住宅的水环境建设提供范例。