碘量法和BOD快速测定仪测定医疗出水BOD浓度的研究

通过碘量法和BOD快速测定仪测定雅安职业技术学院医疗出水BOD浓度,探究这2种方法的差异。采取碘量法测定6份平行样品的溶解氧BOD依次为6.89、6.67、6.73、6.62、7.03、6.76 mg·L^(-1),平均值AV为6.78 mg·L^(-1),标准偏差为0.15,相对标准偏差为0.02,具有统计学意义。采取快速测定法测定6份平行样品的溶解氧BOD依次为6.55、6.45、6.72、6.66、6.54、6.78 mg·L^(-1),平均值AV为6.62 mg·L^(-1),标准偏差为0.12,相对标准偏差为0.02,具有统计学意义。结合国家《医疗机构水污染物排放标准》(GB18466—2005)的排放标准,分别采用国标GB7489—87制定的碘量法和快速检测仪对医疗排放水进行BOD检测,符合污水排放标准。从标准差数据来看,碘量法的标准差为0.151,快速测定法的标准差为0.124,2种方法相比较,快速测定法比碘量法更精确。与快速测定仪的测定步骤相比较,碘量法在测定过程中容易受到环境温度、气压、压力、实验操作误差等因素的影响,相对来说,数据波动比较大。

Pollutant emission reduction effect through effluent tax,concentration-based effluent standard,or both

There are numerous studies comparing different kinds of environmental taxes and standards.However,forms of environmental standards focused by former researchers are usually quantitybased limits/standards(e.g.pounds per day or pounds per unit of output).Concentration-based emission standard(e.g.milligrams per liter of wastewater) as one important form of environmental standard has not been given much attention.In this article,comparable estimates of their probable effect on enterprise pollution reduction will be developed for concentrationbased effluent standards,effluent taxes,and a combination of both.A linear simulation model is used to clearly and obviously compare the effects of effluent taxes and concentration-based standards within the same figure.With one detailed application to the paper industry,some enlightenment and conclusions-as well as the general applicability of these principles-are then provided:Under the same effluent tax rate,enterprises,groups,and industries that are cleaner will reduce more pollutants than those that have higher pollutant abatement costs.It is recommended that effluent taxes are set by avoiding cutting it even at one stroke and considering the feasibility of pollution-reducing technology in various industries.It is necessary to reduce MAC of enterprises to better stimulate enterprises' or industries' emission reduction by preferential measures,such as high tax rate coordinated by speeding up the depreciation of environmental protection equipment.

活性污泥法的多变量最优控制Ⅲ.限制最高和同时限制平均与最高出水BOD浓度

在前文的基础上，进一步研究了更常用的在限制最高和同时限制平均与最高出水有机物浓度两种排放标准的约束条件下，使其运行费用最省的最优周期控制问题．计算结果都表明，最优控制变量ＱＷ和ＤＯ的变化规律都尽可能使其满足约束条件和节省运行费用，但是，当进水负荷变化幅度非常大时，任何控制也难于使出水水质达标，而运行费用还会大幅度增大．相对而言，同时限制平均与最高出水ＢＯＤ浓度是更合理的排放标准，它既有利于污水处理厂的运行管理又能有效地保护受纳水体．初始状态Ｓ（０）对最优控制的影响不大．而Ｘ（０）的影响较大，在本研究中，Ｘ（０）的最优值在２４００—２６００ｍｇ／Ｌ范围内．

基于PIPSBOX测量气态14C流出物装置的设计

14C作为环境影响评价中的重要核素,现有测量技术很难实现核设施气态14C流出物的在线测量。基于PIPSBOX测量技术研制了气态14C流出物在线测量装置的原理样机,模拟了PIPSBOX测量14C的探测效率,理论证明测量的可行性。通过将不同形式的14C气体转化为14CO_(2)形态,以便进行低温分离14CO_(2)提高14C浓度,最后实现PIPSBOX测量14C气体。最终在3 h内,该系统测量14C的最小可探测活度浓度达到0.99 Bq/m3,小于现在连续取样一周的探测下限10 Bq/m^(3),这项工作建立了14C测量新方法,实现了气态14C流出物的在线测量,也为大气中14C在线测量提供参考。

基于CA-GRU的污水处理厂出水总氮浓度预测研究

为了精确预测污水处理厂出水总氮浓度,以呼玛县某污水处理厂公开监测的污水出水水质数据为样本进行了研究。提出了一种基于卷积注意-门控循环单元(CA-GRU)网络的混合模型。首先,使用时间滑动窗口,将数据转换成连续的特征图以作为输入,并从中提取抽象特征。然后,将这些特征映射到网络模型中。最后,通过门控循环单元(GRU)网络模型获得预测值。试验结果显示,CA-GRU模型的均方根误差(RMSE)为0.172,平均绝对百分比误差(MAPE)为0.010。该结果比GRU网络模型低0.108、0.016,比卷积神经网络(CNN)-GRU模型低0.027、0.005,比Attention-GRU模型低0.065、0.007。该结果表明,CA-GRU模型预测效果良好,利用CNN等模型有利于减少冗余信息的干扰。CA-GRU模型能够充分提取污水水质数据在时间和空间上的特征、更准确地预测出水水质总氮含量,具有较高的应用价值。

金川河水BOD_5与COD_(Cr)的关系

同步测定了金川河上不同河段河水的 CODCr(x)与 BOD5 (y) ,通过回归分析 ,发现这两种数值之间存在着线性关系 ,即 :y=0 .6 6 8x- 11.

基于互信息和自组织RBF神经网络的出水BOD软测量方法

针对污水处理过程出水生化需氧量(biochemical oxygen demand,BOD)难以实时准确测量的问题,提出了一种基于互信息和自组织RBF神经网络的软测量方法对出水BOD进行预测。首先,使用基于互信息的方法提取相关特征参量作为软测量模型的输入变量;其次,设计一种基于误差校正-敏感度分析的自组织RBF神经网络,使用改进的Levenberg-Marquardt (LM)算法对网络进行训练以提高训练速度;最后将软测量模型应用于UCI公开数据集及实际的污水处理过程,实验结果表明该软测量模型结构紧凑,训练时间相对较短,预测精度有所提高,能够对出水BOD实现快速准确预测。

Implementation of Effluent Treatment Plants for Waste Water Treatment

This work is aimed at giving emphasis on the present pollution scenario in Bangladesh due to textile effluent and the consequent solution of the problem by installation of effluent treatment plant. Though the medium and small-scale industrial activities have a positive impact on the economy of our country, the increasing industrialization is contributing severe pollution to the environment by the toxic waste discharge. The liquid effluents from industries are causing a major havoc to the environment, ecology, agriculture, aquaculture and public health since the development of textile industries in the country. So, it is time to give a pause to the pollution and phase it out gradually to protect the river system. It had become a prerequisite to set up ETP in each industrial establishment, particularly at dyeing industries that were discharging huge amount of liquid waste to the rivers every day. Since the highest number of factories is of textile category and these types of factories play a major role in polluting the nature, Government’s main focus is on the textile mills and industries related to textile. But, for the successful implementation of ETPs, industry owners will have to be socially responsible and at the same time, government should provide the factory owners with logistic supports and relaxed timeframe to set up ETPs.

Quality of effluents from Hattar Industrial Estate

Of 6634 registered industries in Pakistan, 1228 are considered to be highly polluting. The major industries include textile, pharmaceutical, chemicals (organic and inorganic), food industries, ceramics, steel, oil mills and leather tanning which spread all over four provinces, with the larger number located in Sindh and Punjab, with smaller number in North Western Frontier Province (NWFP) and Baluchistan. Hattar Industrial Estate extending over 700 acres located in Haripur district of NWFP is a new industrial estate, which has been developed with proper planning for management of industrial effluents. The major industries located in Hattar are ghee industry, chemical (sulfuric acid, synthetic fiber) industry, textile industry and pharmaceuticals industry. These industries, although developed with proper planning are discharging their effluents in the nearby natural drains and ulti- mately collected in a big drain near Wah. The farmers in the vicinity are using these effluents for growing vegetables and cereal crops due to shortage of water. In view of this discussion, there is a dire need to determine if these effluents are hazardous for soil and plant growth. So, effluents from different industries, sewage and normal tap water samples were collected and analysed for pH, electrical conductivity (EC), total soluble salts (TSS), biological oxygen demand (BOD), chemical oxygen demand (COD), total nitrogen, cations and anions and heavy metals. The effluents of ghee and textile industries are highly alkaline. EC and TSS loads of ghee and textile industries are also above the National Environmental Quality Standards (NEQS), Pakistan. All the effluents had residual sodium carbonates (RSCs), carbonates and bicarbonates in amounts that cannot be used for irrigation. Total toxic metals load in all the effluents is also above the limit i.e. 2.0 mg/L. Copper in effluents of textile and sewage, manganese in ghee industry effluents and iron contents in all the effluents were higher than NEQS. BOD and COD values of all the industries are also above the NEQS. On the whole, these effluents cannot be used for irrigation without proper treatment otherwise that may cause toxicity to soil, plants and animals as well add to the problems of salinity and sododicity. Similarly, these effluents cannot be used for fish farming.

基于VW-IGRBF神经网络的出水BOD软测量

针对污水处理过程具有复杂非线性特性以及出水BOD难以精确测量的问题,文中提出一种基于变宽度的逆平方根和高斯函数线性组合的RBF神经网络软测量方法。神经网络的激活函数由逆平方根函数和高斯函数线性组合,弥补了单一激活函数在某些区间饱和的问题,提高了隐层激活函数的表达能力和自适应能力。由于激活函数的宽度对模型的泛化性能有较大的影响,因此引入基于核密度的变宽度策略可以有效提高网络泛化能力。文中采用改进LM算法实现了神经网络参数的在线学习。基于污水处理过程实际运行数据的仿真实验表明,所提方法对于出水BOD具有较高的预测精度和良好的自适应能力。

Implications of Secondary Treated Distillery Effluent Irrigation on Soil Cellulase and Urease Activities

Currently distillery effluents have attracted worldwide attention for their application in agricultural land. The present investigation deals with the effect of application of various dosages of distillery effluent irrigation on soil physicochemical, Cellulase and Urease activities in a tropical agricultural field. Experiment was designed in factorial model by using randomized block design. Soil cores were sampled from the selected pits of both polluted and non polluted (control) sites. Majority of soil physicochemical properties (e.g. silt, clay, electrical conductivity, organic matter, total nitrogen contents, cellulase and urease activities) were significantly higher in the samples from polluted site than the non polluted site just after 15 to 30 days of incubation. Although application of effluents at lower rate substantially increased the enzyme activities, the same decreased at high effluent concentration. Prolonged incubation period resulted in gradual suppression of enzyme activity in both polluted and nonpolluted soil samples. Thus, the present investigation suggest that with the passage of time substrate for enzyme activity decreases which in association with residual toxicity resulted in the reduced enzyme activity.

Bio-Geo-Chemical Characterization of Bangladeshi Textile Effluents

Recently industrialization has become one of the most promising contributors for economic development of Bangladesh. However, at the same time, industrial pollution has turned into one of the major problems for human being as well as for the environment. In order to understand the effect of textile effluent (TE) on environmental pollution, TE samples collected from North-west part of the capital of Bangladesh, Dhaka (Savar, Ashulia and Tongi area) were characterized biologically, biochemically and biophysically. Eight potential microorganisms were isolated (3 bacteria and 5 fungi) from the collected TE and two of them were used to de-colorization of TE significantly by bioremediation process. Among the various parameters checked here, some physicochemical properties like TDS, COD, BOD, DO and heavy metals like Cd and Cr were detected in quite high amounts. Altogether, our results indicate that TE is one of the serious pollutants, which could damage environment as well as water body severely.

基于改进AGA-BPNN的工业污水BOD_(5)浓度预测模型

生物需氧量(BOD)浓度为工业污水处理工艺中的重要指标,针对传统污水仪器测量技术在工作环境恶劣、季节性多变等情况下,难以对BOD浓度实时在线监测。本文提出了基于改进AGA-BPNN的工业污水BOD_(5)浓度预测模型,首先以BP神经网络作为基本框架,在原有的自适应遗传算法基础上(AGA),加入阶段参数,调整不同进化阶段的遗传参数设置,提高样本有效性;然后使用改进的交叉率、变异率计算方法,加入自适应的变异点数量,提高遗传算法的泛化能力。在实验结果表明,本文方法对加州大学数据库(UCI)进行测试,预测准确率达到92.77%,高于传统AGA-BP神经网络预测精度。

川西侏罗系气藏产出水生化处理影响因素及技术优化

川西侏罗系气藏产出水中含有泡排剂、破乳剂、缓蚀剂及阻垢剂等多种类型化学药剂,有机物含量高。研究表明,生化处理技术对有机物去除效果较好,能有效降低污水COD,但生化处理易受多种因素影响,COD去除效果不稳定,出水水质指标波动较大。影响生化处理效果的主要因素包括氯离子浓度、营养物质、填料结垢、温度、溶解氧、水力停留时间等。通过实验掌握了生化系统运行的相关工艺参数,建议生化处理运行指标为:进水氯离子浓度18000~22000mg/L、Ca^(2+)含量<100mg/L、溶解氧4~6mg/L、温度20~30℃、水力停留时间130~140h。通过优化生化系统进水水质指标及运行参数,使生化处理后出水COD较优化前平均去除率提高约40%,生化出水发泡力较优化前平均降低约80%,蒸发处理能力大幅提高,蒸馏量由优化前的120~150m^(3)/d提升至180~260m^(3)/d。

对高原地区城市污水处理工艺的对比评估

本文基于前研究学者针对高原独特的环境因素进行城市污水多种处理工艺试验研究,为了找出适合高原生境下在污染物去除方面较好的城市污水处理工艺,对各工艺去除污染物(COD、TN、TP和NH_(3)-N)的去除率和出水浓度达标率作了对比分析。结果表明:一体化MBR和前置厌氧SBR工艺分别对COD和NH_(3)-N的去除效果最佳,A^(2)O工艺同时对TN和TP的去除效果最佳。此外,A^(2)O工艺同时去除4种污染物的效果最佳,并且此工艺处理污染物进水浓度较高,因此,值得考虑A^(2)O工艺作为高原生境下的城市污水处理主流工艺。前置厌氧SBR和一体化氧化沟工艺对4种污染物一级A标准达标率均是100%,但污染物去除率并不都是最佳的,主要可能是因为进水浓度低,表明这两个工艺适合高原生境下处理污染物浓度低的水质。该对比评估研究可对高原地区城市污水处理工艺技术应用发展提供一定的帮助。

核电厂气态流出物监测样品分析中的核素衰变校正应用探讨

在放射性样品分析工作中,样品测量阶段、闲置阶段、采样阶段都涉及到核素衰变校正。根据放射性核素的衰变规律,阐明了这三种类型的衰变校正方法原理及其系数的计算。针对核电厂气态流出物中短半衰期的放射性惰性气体和碘核素的监测分析工作,研究了对监测样品分析结果进行衰变校正的必要性。基于实验测量结果,探讨了衰变校正对γ能谱分析法中核素的活度浓度探测下限的影响。介绍并分析了核电厂气态流出物监测样品分析工作中的衰变校正方案,对于短半衰期放射性惰性气体和碘核素,采用合理保守的衰变校正方案,可减少监测分析中的偏差,同时又可保证统计排放量的偏保守性。

用电解法从富集氰化废液中回收铜的研究

叙述了从富集氰化废液中电解回收铜的试验研究结果。通过电极材料、电流密度、离子共沉积、游离氰、电解时间、温度和极间距等一系列试验，探索电解过程中各项最佳条件，为工业电解提供可靠的工艺参考。

酵母菌处理高浓度含油废水的研究

利用现场筛选到的6株酵母菌,采用活性污泥法工艺对高浓度含油废水进行了连续处理研究。在进水CODCr约12000mg/L,油约3500mg/L,BOD5鄄yeast负荷1.0～2.5kg/(kg·d)情况下,CODCr、油去除率分别达到87.1%～97.3%和92.9～99.8%;并从沉降性角度得出混合酵母菌处理该废水的理想负荷(以单位酵母菌计)为1.0～1.5kg/(kg·d)。

四种化学需氧量测定标准方法的比较

对国内外四种测定低浓度化学需氧量(COD)的方法进行了比对分析。从精密度、准确度、不确定度等方面对这四种方法进行了系统对比。结果表明,在测定低浓度COD的样品时,在准确度方面,除HJ/T399—2007[7]之外的其它三种方法中的任何一种都可以得到稳定可靠的回收率;在精密度方面,5220B.4b[3]和ISO15705—2002[4]的数据与标准文本中的参考数据具有一致性;在不确定度方面,四种方法相差不大,主要影响因素均为样品重复测定引起的不确定度;在方法间的差异及相关性上,采用HJ/T399—2007和其他三种方法得到的结果存在显著差异,而采用其它三种方法测定低浓度COD样品时,得到的结果没有显著差异,并且三种方法之间具有很好的相关性。在实际应用中,5220B.4b、ISO15705—2002和GB 11914—89的数据之间存在较大的随机极差。对比结果表明,5220B.4b、ISO15705—2002和GB11914—89具有可比性,得到的数据都可用。

电化学间接氧化法用于低浓度氨氮废水处理的研究

在氯离子存在条件下，采用电化学间接氧化法对低氨氮的废水进行了实验研究。考察了硝酸盐氮、有机氮和总有机碳（TOC）等其他污染物对氨氮去除效果的影响。结果表明，硝酸盐氮的存在对氨氮的去除影响较小，氨氮去除速率后在0．194～0．269mg·L^-1·min^-1，氨氮的去除反应符合准零级动力学；有机氮的存在会降低氨氮的去除效率，当有机氮浓度大于5mg·L^-1时，氨氮的去除效率从61．1％降低到10％以下；初始TOC浓度的变化对氨氮去除的影响较小，电解90min后氨氮的去除效率都在55％以上。实际废水的电解实验证实，该方法可使出水氨氮优于国家标准（GBl8918—2002）规定的一级A排放标准，表明该方法在低浓度氨氮废水的深度处理上有较好的应用前景。