Fenton试剂处理反渗透浓水的实验研究

针对东北某石化企业炼油污水深度处理过程中产生的反渗透浓水的组成及特点,采用Fenton试剂对含难降解有机物的反渗透浓水进行了处理,系统地研究了VH2O2/VFe2+、反应时间、浓水初始pH、H2 O2投加量等因素对浓水中COD去除率的影响.研究结果表明,H2 O2投加量是主要影响因素,其次是浓水初始pH、反应时间以及VH2O2/VFe2+;在各因素较佳水平条件下,Fenton试剂可以有效去除反渗透浓水中的有机物,COD的去除率可以达到87.42%.大幅度降低其中难降解有机物含量,研究结果对企业废水达标排放及水资源的有效利用具有重要意义.     

基于SAPSO-BP网络模型的海洋平台落物碰撞损伤分析

为了确保海洋平台作业过程中落物坠落对甲板撞击后的结构安全,对坠落立管撞击海洋平台甲板的过程进行了非线性仿真分析。运用ANSYS/LS-DYNA建立有限元模型,对坠落立管不同撞击角度撞击海洋平台甲板进行模拟计算,得到甲板在不同工况下的损伤情况。运用1种自适应性变异的粒子群优化算法SAPSO与BP神经网络结合［1］,对海洋平台进行落物碰撞损伤分析。研究结果表明:落物与垂直方向偏离5°～10°为坠落时最危险的工况。SAPSO-BP提高了BP神经网络的拟合能力,减小了拟合误差,提高了拟合精度,验证了SAPSO-BP网络模型的实用性和可靠性。综合考虑制定适用于海洋平台落物安全的工作程序和平台及设备的防护措施,为海洋平台作业中落物风险评估和海洋平台作业安全保障提供参考。     

大气中的硝酸及其相关因素

采集了173个大气样品,测定其HNO_3含量,同时测定了O_3、NO_2、NH_3、t、RH,并对数据进行了多元逐步回归处理。结果表明,O_3与HNO_3相关最好。与HNO_3呈正相关的是O_3、NO_2、t;呈负相关的是NH_3、RH。通过HNO_3、NH_3的浓度,计算了平衡常数,证明在低湿度下大气中存在固态NH_4NO_3与气态HNO_3、NH3的平衡。     

成矿流体地球化学界面:Ⅲ应用实例研究

本文以田湾金矿带为例 ,研究了地球化学界面对流体成矿的控制作用。研究发现 ,田湾金矿带流体成矿的最佳地球化学界面主要为 :成矿环境条件变异界面 (区域地球物理条件变异界面、地质条件突变界面 ) ,流体性质演化界面 (温度界面、压力界面、pH界面、Eh界面 )和流体 -环境作用界面     

混凝去除垃圾渗滤液中DOM的实验研究

选取氯化铁(FeCl3.6H2O)为混凝剂,以经0.45μm膜和1nm膜分子切割的垃圾渗滤液为研究对象,通过混凝剂投加量和混凝pH值实验,研究了垃圾渗滤液中DOM的去除情况,并比较了两种不同分子量水平的渗滤液中DOM的混凝去除特点。研究表明,pH值是影响渗滤液DOM去除的主要因素,氯化铁在pH=5、投加量为4g/L的条件下混凝效果最佳。混凝pH值对大分子量渗滤液中DOC去除的影响较大;而两种分子量水平的渗滤液UV254的去除差异不大。     

Relative growth and production of the estuary grouper Epinephelus salmoides under different stocking densities in floating net-cages

Studies on the relative growth and production of the estuary grouper Epinephelus salmoides Maxwell were conducted in floating net-cages at 5 different stocking densities to determine the optimal level for stocking for commercial culture. The fish were stocked at densities of 15, 30, 60, 90 and 120 fish per m³, and reared for a period of 8 months. Results of the present study indicated that fish stocked at a density of 60 fish m^-3 grew equally fast and showed a food conversion ratio, mortality rate, and condition factor comparable to those at the lower stocking densities of 15 and 30 fish m^-3. At the end of the experiments, net-yield and production at this level of stocking density (60 fish m^-3) were not significantly different from those at the higher stocking densities of 90 and 120 fish m^-3, but showed increases of 86.7% over those at a stocking density of 30 fish m^-3 and 294.2% over those at a stocking density of 15 fish m^-3. The stocking density of 60 fish m^-3 is therefore taken as the optimal stocking rate for economical production of estuary groupers in floating net-cages. The estuary groupers take 7 to 8 months to grow from 15–16 g to marketable size (>500 g) at a stocking density of 15 fish m^-3, 8 to 9 months at a stocking density of 30 to 60 fish m^-3 and 11 to 12 months at 90 to 120 fish m^-3.     

示波极谱法测定空气中硫化氢

本文采用NaOH、EDTA和三乙醇胺混合溶液吸收空气中H2S3然后直接对吸收液进行示波段谱测定。方法的线性范围为0．003-5．0ppm，最低检出浓度为3ppb，相对标准差为1．2～2．7％，回收率为91．4～104．6％。应用本法测定了11份空气样品，测定结果与亚甲基蓝比色法一致。     

土壤有机碳地球化学及其与岩溶作用的关系──以桂林丫吉村岩溶试验场为例

岩溶土壤有机碳地球化学研究表明：岩溶土壤是有机碳的巨大储库；土壤有机碳含量以松结态为主，紧结态次之，稳结态最少；土壤表层，鞍部、坡地土壤有机碳较活跃（较多松结态），为岩溶作用CO2的丰富来源。有机碳可氧化性分级分析表明：表层土壤有机碳中易氧化态占60－85％，A层土壤较B层更易被氧化；土壤来源CO2是岩溶驱动CO2的潜在动力。从鞍部－坡地－洼地，B层土壤有机磷可氧化性由弱到强递增。野外监测表明：在干、晴气候下，岩溶土壤CO2含量高且CO2释放速率大，岩溶作用欠发育；在湿雨气候下．岩溶土壤CO2含量及CO2释放速率急剧降低，岩溶作用发育；雨后转晴．岩溶土壤CO2含量及CO2释放速率逐渐增高，岩溶作用减弱。     

Influence of deployment time and surface wind speed on the accuracy of measurements of greenhouse gas fluxes using a closed chamber method under low surface wind speed

As a convenient method, the closed chamber method has been applied to determine gaseous emission fluxes from fully open animal feeding operations despite the measured fluxes being theoretically affected by deployment time, wind speed over the emitting surface and detected gas mass. This laboratory study evaluated the effects of deployment time (0 to 120 min) and external surface wind speed (ESWS) (0.00, 0.25, 0.50, 0.75, 1.00, 1.50 and 2.00 m sec^-1) on the measurement accuracy of a 300 mm (diameter) × 400 mm (height) (D300×H400) closed chamber using methane (CH₄), nitrous oxide (N₂O) and sulfur hexafluoride (SF₆) as reference gases. The results showed that the overall deviation ratio between the measured and reference CH₄ fluxes ranged from 9.99 % to -37.32 % and the flux was overestimated in the first 20 min. The measured N₂O and SF₆ emissions were smaller than the reference fluxes using the chamber. N₂O measurement accuracy decreased from -14.47 to -35.09% with deployment time extended to 120 min, while SF₆ accuracy sharply increased in the first 40 min, with the deviation stabilizing at approximately -5.00%. CH₄, N₂O and SF₆ measurements were significantly affected by deployment time and ESWS (P<0.05), and the interaction of those two factors greatly influenced CH₄ and SF₆ measurements (P<0.05). With the D300×H400 closed chamber, deployment times of 20 to 30 min and 10 to 20 min are recommended to measure CH₄ and N₂O, respectively, from the open operations of dairy farms under wind speeds lower than 2 m sec^-1.

Implications: This study recommended the suitable deployment times and wind speeds for using a D300 × H400 closed chamber to measure CH₄, N₂O, and SF₆ in an open system, such as a dairy open lot and manure stockpile, to help researchers and other related industry workers get accurate data for gas emission rate. Deployment times of 20 to 30 min and 10 to 20 min were recommended to measure CH₄ and N₂O emissions using the D300 × H400 closed chamber, respectively, from the open operations of dairy farms under wind speeds lower than 2 m sec^?1. For the measurement of SF₆, a typical tracer gas, a deployment of 70 to 90 min was suggested.     

生态农业的给排水循环系统的探讨

生态农业的发展，是经济、社会和环境保护协调发展的产物。作者提出生态农业的给排水循环系统作为现有模式的延伸和补充，让生态农业在经济、社会、环境的协调发展中发挥更大的作用，最大限度地消除农业污染，为农业可持续发展提供技术支持和可靠保证。