Treatment of Refractory Organics Contained in Actual Agro‐Industrial Wastewaters by UV/H2O2

In this work, the treatment of actual agro‐industrial wastewaters (IWW) by a UV/H₂O₂ process has been investigated. The aqueous wastes were received from industrial olive oil mills and then treated by laboratory scale physicochemical methods, i. e., coagulation using ferrous and aluminum sulfate, decantation, filtration and adsorption on activated carbon. These wastes are brown colored effluents and have a residual chemical oxygen demand (COD) in the range of 1800 to 3500 mgO₂ L^–1, which cannot be further eliminated with physicochemical processes. The UV/H₂O₂ treatments were carried out under monochromatic irradiation at 254 nm using a thermostated reactor equipped with a mercury vapor lamp located in an axial position. The effects of initial H₂O₂ concentration, initial COD, pH and temperature have been studied in order to determine the optimum conditions for maximum color and COD removals. The experimental results reveal the suitability of the UV/H₂O₂ process for both removal of high levels of COD and effectively decolorizing the solution. In particular, 95% of color removal and 90% of COD removal were obtained under conditions of pH = 5 and 32°C using 2.75 g H₂O₂ g^–1 COD L^–1 during 6 h of UV‐irradiation. The treatment is unaffected by pH over the range 2 to 9. In addition, the COD removal is improved by increasing the temperature, whereas the color removal has not been affected by this parameter. The results show that the hydroxyl radicals generated from the catalytic decomposition of H₂O₂ by UV‐irradiation of the solution could be successfully used to mineralize the organics contained in IWW. The mineralization of the organics seems to occur in three main sequential steps: the first is the rapid decomposition of tannins leading to aromatic compounds, which are confirmed by the decolorization of the IWW; the second step corresponds to the oxidation of aromatics leading to aliphatic intermediates, which occurs by the cleavage of an aromatic ring, and is established by the removal of aromatics, and the final step is the slow oxidation of the aliphatic intermediates, which is measured by the COD removal.     

Experimental research on the influence of two cultivation practices on rainfall runoff- and （sandy and muddy） sediment-generating processes in purple soil environment

Rainfall simulations have been conducted to study the soil erosion process of purple soil in two cultivation practices---contour cultivation and downslope cultivation. Results showed that under the two cultivation practices, the surface runoff can be described by the logarithmic function formula. In the initial period of rainfall, the amount of runoff increased with the rainfall duration and 20 minutes later it became relatively constant. The changing process of soil erosion rate may be described by the logarithmic function formula. The erosion rate increased with the rainfall duration and 20 minutes later it also became constant. Under downslope cultivation condition, the soil erosion rate increased more significantly than that under contour cultivation condition in the case of gentle rainfall intensity, and there is no obvious difference in erosion rate for downslope cultivation and contour cultivation practices. However, with increasing rainfall intensity the soil erosion rate under the downslope cultivation condition could be more than 30 times that under the contour cultivation condition. But this kind of difference would be reduced to some extent in the case of heavy rain.     

荒漠蓝藻规模化培养试验

以人工生物土壤结皮治理沙化土地技术是近年来新兴的绿色环保固沙技术,是目前沙区生态恢复研究的热点。然而,用于人工生物土壤结皮培养的荒漠蓝藻等生物体的产量是限制该技术大规模应用的瓶颈。为阐明荒漠蓝藻规模化培养的生长特征及其限制因子,以分离于腾格里沙漠蓝藻结皮中的优势荒漠蓝藻——鱼腥藻（Anabaena cylindrica）、具鞘微鞘藻（Microcoleus vaginatus）、念珠藻（Nostoc carneum）、席藻（Phormidium sp. NIES-2121）、伪枝藻（Scytonema sp. NIES-4073）、爪哇伪枝藻（Scytonema javanicum）和单歧藻（Tolypothrix tenuis）为研究对象,测定了不同扰动时长下荒漠蓝藻的生长特征和产量,分析了荒漠蓝藻的生长与扰动时长、温度、光照强度、光合有效辐射、pH和电导率对荒漠蓝藻的影响。结果显示：荒漠蓝藻接种后干重先迅速增加后逐渐趋于稳定,而6 h和12 h扰动下干重在培养后期高于3 h扰动;荒漠蓝藻在3、6、12 h扰动下的总质量分别为每培养池（15 m³）0.858、0.940、0.841 kg;在3 h和12 h扰动下荒漠蓝藻干重与日均温度呈显著二项式相关,与日均光照强度和日均光合有效辐射呈显著负相关;荒漠蓝藻总质量与有效积温显著正相关。6 h扰动时长下荒漠蓝藻的总质量最高,且6 h扰动下荒漠蓝藻长势好于3 h,较12 h扰动耗能小。在荒漠蓝藻规模化培养时应将扰动时长设置为6 h,且确保生长期内的有效积温应不低于145 ℃。     

The effects of co-cultivation of pearl mussels and fishes on water pollution control in middle or small sized water

Our field experiments showed that the cultivation of pearl mussels formed a new biocoene composed of filamentous algae, protozoa, porifera and coelenterate. It effectively reduced nitrogen, phosphorus,chemical oxygen demand and biochemical oxygen demand in the water by 67.3%, 73.2%, 38.1% and 15.5%,respectively, during May to September 1998 when the water eutrophication was developing. This could control water eutrophication and produce pearls, shellfish meat and shells. This is an economical and effective way to control water eutrophication by using the ultra strong filtering capability of freshwater pearl mussels.     

瘤背石磺室内温箱养殖试验

为了探索人工养殖的方法，在实验室温箱条件下对瘤背石磺(Onchidiwns stnuma)的摄食条件及适口饵料进行了研究。试验结果表明，瘤背石磺最适摄食条件及饵料为：控制温箱温度22～26℃；控制湿度接近100％；采用人工饵料平台，即海边泥土涂上螺旋藻。     

全雌鲻鱼培育的进一步研究

为了验证和完善培育全雌鲻鱼的技术路线，我们在首次培育试验成功的基础上，通过调整用药剂量和增加试验鱼数量，进行第二次培育试验。试验选用体长2．8－3.5cm、性别未分化的鲻鱼苗，分为三组。高剂量组和低剂量组分别投喂拌有不同剂量17β-雌二醇的饲料，持续6个月，对照组则投喂不含药物的饲料，结果显示，高剂量组鲻鱼全部分化为雌性，低剂量组雌性率达90％，对照组雌性率仅为10％。与第一次试验结果相比较，我们认为，全雌鲻鱼培育的技术路线更为成熟和合理，为将来推广应用提供可靠的技术保证。     

鲍人工养成阶段养殖环境中的周丛纤毛虫

应用定性和定量方法,研究了人工养成阶段杂色鲍Haliotis diversicolor外壳的周丛纤毛虫的种类组成和优势类群演变。共观察到3纲9目35属58种纤毛虫,缘毛类Peritrichida的种类最多,有23种。在养成阶段的早期,周丛纤毛虫的优势类群为钟虫类;在养成阶段的中、后期,周丛纤毛虫的优势类群演变为聚缩虫类,其中交替聚缩虫Zoothamnium alternans占绝对优势;文中还对各种环境因子对养殖环境中的周丛纤毛虫的影响进行了分析。     

非测绘类专业测量学实践教材编写浅析

非测绘类专业测量学教材在编写的过程中,对不同专业和不同学校容易缺少针对性。本文在介绍校本教材《测量学实验与实习教程》的基础上,总结了实践类教材编写的几点体会:教材编写的指导思想应体现科学性与适用性;内容的设计突出职业能力的培养;实验案例注重融合产学研;与理论教材互为有机整体。     

Decomposition of Phytoplankton in Seawater. Part I: Kinetic Analysis of the Effect of Organic Matter Concentration

Decomposition experiments were conducted on cultured phytoplankton (Skeletonema costatum) in seawater containing decomposer and consumer of size less than 500 μm. We determined the decomposition rates of bulk particulate organic matter (POM), the ratio of labile to semi-refractory fractions in the POM, and the POM carbon/ nitrogen (C/N) ratio during decomposition. To identify the kinetic mechanisms involved in the reactions of different order (e.g., first- and second-order), we studied the sensitivity of reaction rates to the initial concentration of POM, ranging from 2.4 to 71 mg-C L⁻¹. The results showed that decomposition consists of two first-order reactions: decomposition of labile and of semi-refractory particulate organic carbon (POC). The decomposition rate constants found for labile (0.13 day⁻¹ at 20°C), and semi-refractory POC (0.008 day⁻¹ at 20°C), and the carbon weight ratio of semi-refractory POC (13% at 20°C), were insensitive to the initial organic matter concentration. The time-dependence of the C/N ratio was also independent of this initial concentration. The decomposition rate constants and the content of semi-refractory POC did not change, regardless of the absence or presence of 25–500 μm organisms in natural seawater. This revised version was published online in July 2006 with corrections to the Cover Date.     

池塘主养团头鲂鱼种高产技术试验

试验了主养团头鲂的合理放养密度；配养品种的最佳选择及放养比数；优质配合颗粒饲料；驯化投饵；水质调控等高产技术。试验结果：１９．５９亩水面，总净产鱼种１３１３０．０ｋｇ，平均亩净产鱼种６７０．０４ｋｇ，其中团头鲂亩净产３９７．５０ｋｇ，平均尾重３３．９７克，亩纯收入３３５０．６６元，投入产出比为１：２．３３。