Ecology and seasonal variation of microalgal community in an oil refinery effluent holding pond: monitoring and assessment

The microalgal community as primary producers has to play a significant role in the biotic and abitoic interactions of anyaquatic ecosystem. Whenever a community is exposed to a pollutant, responses can occur because individuals acclimate topollutant caused changes and selection can occur favouring resistant genotypes within a population and selection among species can result in changes in community structure. The microalgal community of industrial effluent treatment systems arecontinuously exposed to pollutants and there is little data available on the structure and seasonal variation of microalgalcommunity of industrial effluent holding ponds, especially of acomplex effluent like that of refinery. The aim of the presentstudy was to investigate the annual variation in the ecology,biomass, productivity and community structure of the algalcommunity of a refinery effluent holding pond. The results ofthe study showed the pond to be a eutrophic system with a resistant microalgal community with distinct seasonal variation in species composition.     

象山港网箱养殖对海域环境的影响及其养殖环境容量研究

以象山港海域的潮流模型和物质输运模型为基础,建立了各网箱养殖区的氮、磷污染物排放量与研究海域水质之间的响应关系,对该海域的养殖污染状况进行了模拟,讨论了该海域的网箱养殖环境容量.结果表明,象山港内的氮、磷浓度在养殖区密集的港顶海域超出一类水质标准;该海域的氮、磷养殖环境容量分别为670.74t/a和77.32t/a.目前,象山港内各网箱养殖区的污染物排放量已超出其容量,需进行削减.     

氧化塘水力特性模型研究

氧化塘是一种被广泛应用且运行费用较低的污水处理设施，其流型有多种模型可供采用，但主要模型参数纵向扩散系数（D）和扩散因素（d）均难准确预测，为了满足这些模型的通用性就需要建立所需参数的预测方程。通过氧化塘模型研究，利用示踪实验技术测定了水力逗留时间分布，提出了一种计算氧化塘模型纵向扩散系数D的经验公式，为求取扩散因素d或扩散传质准数Pe提供了简便方法。用所得经验公式求得胜利油田桩西联采油废水氧化塘Pe值，与实测值较好吻合，相对偏差为6．61％。     

Investigation of geothermal energy utilization for thermal regulation of aquaculture raceway

ABSTRACT

Aquaculture raceway temperature has a direct impact on the aquatic specie being reared. In regions that undergo significant seasonal temperature variations, the thermal management of the raceway temperature becomes a challenge, directly impacting the production yield. This study investigates a novel approach to regulate the raceway temperature in a sustainable way by utilizing geothermal energy. A numerical energy model was developed to simulate heat transfer in a geothermal system encompassing both the individual borehole heat exchangers and their thermal interactions. Simulations were conducted for different configurations of the geothermal system over a complete seasonal cycle. Results show that flow rate, number of boreholes and the borehole spacing influence the temperature of the fluid at the raceway inlet. An increase in the number of boreholes provided better thermal regulation but an increase in the flow rate through the boreholes provided less thermal regulation. A borehole spacing of 6 m was found to be appropriate to reduce thermal interference. It was also observed that an increase in the fraction of the fluid passed through the geothermal system enhances the overall thermal regulation, with higher thermal regulation at lower flow rates. Results show that when 100% of the fluid passed through a 64 boreholes geothermal system, the average regulated raceway inlet temperature was 23% higher in winter months and 16% lower in summer months at the flow rate of 21.5 L/s compared to than at 43 L/s.     

超深厌氧塘的经济分析

本文采用系列设计法，对超深厌氧塘的经济可行性进行了分析研究，建立了费用估算模式并计算出临界地价，为实际应用提供了依据。     

n级串联氧化塘设计优化模型

通过数学理论推导，得出ｎ级串联氧化塘设计最佳参数的计算模式，证明了比Ｍａｒａ猜想更一般的结论，扩充了前人研究结果，为多级串联氧化塘设计优化提供理论参考依据。     

A study on the hydraulics of waste stabilization pond

In this study, tracer tests and organic removal tests were conducted on three different ponds in the purpose of evaluating the influence of the flow velocity and dispersion on the hydraulic efficiency of the pond. The authors have compared the hydraulic flow patterns among ponds with different configurations. Experimental and theoretical analyses were performed. This study indicated that the flow characteristics of square ponds are different from that of baffled ponds; the flow velocity and dispersion are equally important factors which affect the pond hydraulics; the number of inserting baffles can be optimized; and the hydraulic efficiency of multistage ponds is superior to that of baffled ponds.     

综合生物塘处理城镇污水研究

报道了一种新的高效低能耗的污水处理塘系统的中试研究结果。本生物塘系统分为三个功能区域，分别为污水净化区，水质修饰区和综合利用区，水生维管束植物呈带状分布于塘系统中，在时间上和空间上进行不同搭配组合。较之传统氧化塘和一般的水生植物塘、综合生物塘的处理效果较好。ＣＯＤ、ＢＯＤ、ＴＳＳ、氮、磷等污染组分法除效率较高，细菌，病毒及诱变活性明显下降，在污水净化的同时，收获大量的水生植物及鱼，蚌等水产品，水质     

10万m3/d污水处理厂新型稳定塘工艺技术经济分析

介绍了沙营污水处理厂稳定塘工艺的构成特点及2年来实际运行效果。效益分析表明,新型稳定塘工艺通过在厌氧塘安装弹性填料、在好氧塘增加表面曝气机,在养鱼塘放养各类鱼苗、在生态塘种植莲藕、芦苇,从而形成了人工可以控制的生物氧化过程来处理城市污水,具有基建投资省、维护管理方便、运行费用低等特点,在土地资源丰富的中小城市具有良好的应用前景。     

氧化塘底泥与稻草堆肥过程中养分变化研究

氧化塘污泥中含有较丰富的各种氮、磷养分,将氧化塘污泥堆肥处置后农用是一种有效的处置方式。采用静态强制通气堆对氧化塘底泥进行堆肥处理,对堆肥过程中氮磷的变化规律进行了研究。试验结果表明,堆肥过程中总氮含量下降了17.5%,总磷含量上升了47.0%,堆肥的时间以49d左右为宜。