基于神经网络的活性污泥系统建模及其控制

针对松江污水厂污水处理活性污泥系统,采用神经网络技术进行建模试验研究,在对实际运行数据剔除异常数据后,将样本数据随机分成训练样本、检验样本和测试样本.用试凑法确定合理的神经网络隐层节点数,用检验样本实时监控训练过程从而避免"过训练"现象,用多次改变网络初始连接权值求得全局极小点,从而建立了泛化能力较好的基于神经网络的活性污泥系统数学模型.利用建立的神经网络模型,对活性污泥系统运行情况的仿真与控制进行了分析研究.示例研究表明:神经网络技术能较好地应用于活性污泥系统的建模与控制,有很好的理论与实践意义.     

高铁酸盐氧化降解水中苯酚的动力学及机理研究

以自制高铁酸钾(K₂FeO₄)为原料，探讨了影响高铁酸盐氧化降解苯酚的主要因素，并研究了苯酚降解的动力学特征和反应机理。结果表明，高铁酸盐加入量、pH值、持续搅拌、反应温度、反应时间都影响苯酚去除效果。其中高铁酸盐加入量是影响苯酚去除效果的关键因素，高铁酸盐氧化降解苯酚的最佳pH值范围为9～10，持续搅拌和提高反应温度只影响苯酚降解速率而不影响苯酚降解率。苯酚的降解过程遵循一级反应动力学模型。苯酚被高铁酸盐氧化生成CO₂、H₂O以及一部分难矿化的有机物。     

湿式旋流脱硫除尘一体化装置在燃煤锅炉烟气净化上的应用

某中药厂4 t/h燃煤锅炉烟气采用湿式旋流脱硫除尘一体化装置取得了良好的效果,经实际运行测定除尘率达95%,脱硫率达77%,排出的烟气均能达到排放标准.该净化装置具有旋风水膜除尘器和湿式旋流板洗涤器的双重功能,通过介绍该一体化装置的机理、设计参数和技术经济分析,为燃煤锅炉烟气的脱硫除尘提供参考.     

磷酸活化-微波热解改性污泥对镉的吸附性能

以城市污水处理厂剩余污泥为原料,利用磷酸活化-微波热解制取改性污泥。以此污泥作为吸附剂,对含Cd2+废水进行了吸附实验研究。考察了溶液反应时间、Cd2+浓度、pH值和吸附剂用量对镉吸附去除效果的影响;利用等温吸附实验作出吸附等温线,并考察了改性污泥吸附剂吸附Cd2+的动力学方程。实验结果表明,改性污泥对Cd2+有良好的吸附性能,吸附最佳pH值为6.0,吸附较好地符合一级动力学吸附模型和Langmuir-Freundlich等温吸附方程,吸附为物理吸附,吸附反应发生12 h后达到吸附平衡。     

大孔树脂吸附去除水中的2,4,6-三硝基甲苯

研究了2种大孔树脂XAD-4和NDA-804对水中的TNT的吸附行为。2种树脂对TNT的吸附等温线表明,温度的升高有利于吸附,在35℃条件下XAD-4树脂与NDA-804树脂对TNT的最高平衡吸附量分别达82.86 mg/g和94.26mg/g。采用Langmuir方程和Freundlich方程用于吸附等温线的解释,结果表明,吸附等温线更加符合Langmuir模型,相关系数均大于0.99。TNT在2种树脂上的吸附符合准二级动力学方程,TNT初始浓度越低,达到吸附平衡所需时间越短,在1 h内可达到吸附平衡。采用NDA-804处理对TNT废水,废水中TNT浓度由103.58 mg/L降至0.4 mg/L,去除率达99.6%,吸附后的树脂采用pH=2的乙醇和盐酸的混合液脱附可再生,高浓度再生溶液经蒸馏可回收TNT,实现了废水治理与资源化。     

纳米生态基对水产养殖污水的处理效果

采用三因子四水平的正交设计,实验研究了纳米生态基在不同温度、溶解氧和水力停留时间下对水产养殖污水的处理效果,确定了纳米生态基处理养殖污水的最佳条件。结果表明,含氨氮和亚硝氮浓度较高的模拟养殖污水用纳米生态基挂膜,所需时间约为22 d。纳米生态基对氨氮的去除效果明显,平均去除率达到93.5%。对氨氮去除率的影响程度,水力停留时间>温度>溶解氧。当温度为30℃,DO为5.43 mg/L,HRT为0.33 h时,纳米生态基对氨氮的处理能力最佳,去除率达到94.6%。纳米生态基对亚硝氮的平均去除率为69.3%。对亚硝氮去除率的影响程度,水力停留时间>溶解氧>温度。当温度为21℃,DO为6.40 mg/L,HRT为0.33 h时,纳米生态基对亚硝氮的处理能力最佳,去除率为71.5%。纳米生态基处理养殖污水的最佳条件:温度为30℃,DO为6.40 mg/L,HRT为0.33 h。     

不同功能区空气负离子的监测分析

监测了西宁地区不同功能区空气负离子状况，以公园游览区空气负离子浓度最高，平均３５８个／ｃｍ＾３；工业区最低，平均浓度２５９个／ｃｍ＾３。各功能区空气负离子浓度明显不同，Ｐ〈０．０１。用空气负离子浓度、空气离子单级系数和安培空气质量评价指数评价各功能区空气质量，从好到差依次为：公园游览区、生活居住区、商业交通繁忙区、工业区。３种评价指标结果相同，符合一般规律。     

Sustainable development of food production: a case study on scenarios for pig production

To study future, sustainable production systems, a step-wise method was used to create three future scenarios for pig production based on different sustainability goals. The first scenario focused on animal welfare and the natural behavior of the animals. The second targeted low impacts on the environment and the efficient use of natural resources. The third scenario aimed at product quality and safety. Each scenario fulfilled different aspects of sustainability, but there were goal conflicts because no scenario fulfilled all sustainability goals. The scenarios were then parameterized. The environmental impact was calculated using the life-cycle assessment (LCA) methodology, and the economic cost was calculated from the same data set. The cost per kilo of pork was highest for the animal welfare scenario and similar for the other two scenarios. The environmental scenario had the lowest environmental impact, and the product-quality scenario the highest. The results are discussed based on different future priorities.     

Removal of azo dye from water by magnetite adsorption-Fenton oxidation.

The aim of this study is to highlight the possibility of using powder magnetite adsorption-Fenton oxidation as a method for removal of azo dye acid red B (ARB) from water. The adsorption properties of magnetite powder towards ARB were studied. The oxidation of adsorbed ARB and regeneration of magnetite adsorbent at the same time by Fenton reagent (hydrogen peroxide [H2O2] + iron (II) [Fe2+]) in another treatment unit with a smaller volume was also investigated. The efficiency of Fenton oxidation of ARB was compared for the reaction carried out in solution and on magnetite. The magnetic separation method was used to recover magnetite after adsorption or regeneration. The results indicated that the adsorption rate was fast. The capacity was strongly dependent on pH and inorganic anions, and pH 3.8 was optimal for the adsorption of ARB. The adsorption can be described well using the Langmuir model. The oxidation was more efficient for ARB adsorbed on magnetite than in solution. The adsorption capacity of magnetite increased significantly after regeneration, which was the result of an increase in surface area of the adsorbent and change of elemental ratio (oxygen:iron [O:Fe]) on the surface. The maximum adsorption capacity for ARB was 32.4 mg/g adsorbent.     

Lead biosorption and desorption by intact and pretreated spirulina maxima biomass

In order to search for locally available and untried biomaterials in China with high removal capacity of heavy metals from wastewater, the feasibility of Spirulina maxima as biosorbent for lead removal and recovery from aqueous solution was investigated. The lead biosorption was studied by using intact biomass and pretreated biomass of S. maxima. The effects of operational conditions (e.g. pH, contact time, biomass concentration etc.) on lead biosorption were investigated. The biosorption was solution pH dependent and the maximum adsorption was obtained at a solution pH of about 5.5. The adsorption equilibrium was reached in 60 min. The biosorption followed the Freundlich isotherm model. The maximum removal ratios of lead were about 84% in intact biomass and 92% in pretreated biomass. The lead adsorbed could be desorbed effectively by 0.1 M nitric acid, EDTA and hydrochloric acid. The results in this study indicated that pretreated biomass of S. maxima was a promising candidate for removing lead from wastewater.     

废印制线路板真空热解渣分选与组成分析的研究

在自行设计制备的真空热解炉中进行了废印制线路板的热解实验，得到固体、液体和气体产物。着重研究了热解固体渣中金属铜和非金属玻璃纤维的物理分选、热解固体渣分析及有氧煅烧对玻璃纤维纯度的影响。结果表明，物理分选效率很高，金属铜的回收率和纯度接近100%；热解固体渣含30.35%的铜、56.21%的玻璃纤维和13.45%的炭黑；有氧煅烧去除炭黑可得到高纯度的玻璃纤维。     

Investigation on the photoreactions of nitrate and nitrite ions with selected azaarenes in water

The photoreactions of selected azaarenes with nitrate and nitrite ions were investigated under irradiation at lambda = 313 nm. The excitation of both anions leads to several photochemical reactions forming mainly hydroxyl radicals and nitrogen oxides. The purification capability of natural waters i.e. the oxidation of inorganic and organic substances results from the formation of hydroxyl radicals. Nitrated isomers of azaarenes were found among the main products of the investigated photoreactions. The nitrogen oxides were responsible for the production of nitrated derivatives which possess a high toxic potential. Their formation was explained by the parallel occurance of two mechanism, a molecular and a radical one. The molecular mechanism became more important with increasing ionisation potentials of the azaarenes. The spectrum of oxidized products corresponded to the one got in the photoreactions of azaarenes with hydrogen peroxide. The formation of several oxidation and nitration products of the pyridine ring with its low electron density was explained by the reaction of excited states of azaarenes. The photoreactions with nitrite ions only led to the formation of oxidized and nitrated products. Nitroso products were not formed. The reactivity of nitrogen monoxide is too low for its reaction with the azaarenes.     

污泥活性炭对复合染料的脱色及其重金属浸出毒性

用自制的污泥活性炭处理亚甲基蓝与酸性品红组成的染料废水,研究了pH、吸附时间、温度等因素对复合组分染料废水脱色率的影响,测试分析了污泥活性炭在处理亚甲基蓝与酸性品红复合组分染料废水过程中的重金属浸出毒性。结果表明:与处理单一组分染料废水相比较,处理复合染料废水时pH的影响较为复杂,2种染料在污泥活性炭上存在竞争吸附,但是污泥活性炭对复合组分染料的脱色效果较好。污泥活性炭对复合染料的吸附过程符合Langmuir型吸附。在处理染料废水的过程中,污泥活性炭中的重金属镉、锌及铬会浸出,重金属镉、锌的浸出浓度符合国家标准,但铬的浸出浓度已接近国家标准上限。     

Heavy metal speciation and phytotoxic effects of three representative sewage sludges for agricultural uses

The environmental impact of sewage sludges depends on the availability and phytotoxicity of their heavy metal. The influence of representative sludges (dewatered anaerobic, pelletization, and composted sludge) on the availability of heavy metals, and their effects on seed germination were compared. The total heavy metal concentrations were below the maximum permitted for land-applied waste and the differences among them were small. The DTPA-extracted metal concentrations were rather different. The sequential extraction of the compost showed a slight increase in Cd and Cu availability, and a decrease in the availability of Fe, Mn, Ni and Zn. Pelletization increased the availability of Ni and slightly reduced that of Cr. The dewatering sludge led to greater availability of Cr and Mn but reduced the concentration of Cd. The three different sludges also affected seed germination and root elongation in different ways. The most serious adverse effects were caused by the dewatered sludge extract.     

污泥基活性炭吸附Cu2+的应用研究

以城市污水处理厂剩余污泥为原料，以ZnCl₂为活化剂制取污泥基活性炭。以此污泥基活性炭为吸附剂，对含Cu²⁺的废水进行了吸附实验研究。考察了溶液pH值、Cu²⁺的起始浓度对Cu²⁺离子吸附量的影响；利用等温吸附实验作出吸附等温线，并考察了污泥基活性炭吸附剂吸附Cu²⁺的动力学方程。实验结果表明，污泥基活性炭对Cu²⁺具有良好的吸附性能。吸附的最佳pH值为5；吸附符合Langmuir和Freundlich吸附等温方程，吸附为优惠吸附，吸附量随着吸附质溶液浓度的增加而增大；吸附平衡时间为4 h，吸附动力学符合二级动力学方程。     

Effectiveness and mechanisms of hydrogen sulfide adsorption by camphor-derived biochar

The characteristics and mechanisms of hydrogen sulfide (H2S) adsorption on a biochar through pyrolysis at various temperatures (100 to 500 degrees C) were investigated. The biochar used in the current study was derived from the camphor tree (Cinnamomum camphora). The samples were ground and sieved to produceparticle sizes of 0.4 mm to 1.25 mm, 0.3 mm to 0.4 mm, and <0.3 mm. The H2S breakthrough capacity was measured using a laboratory-designed test. The surface properties of the biochar were characterized using pH and Fourier-transform infrared spectroscopy (FTIR) analysis. The results obtained demonstrate that all camphor-derived biochars were effective in H2S sorption. Certain threshold ranges ofthepyrolysis temperature and surfacepH were observed, which, when exceeded, have dramatic effects on the H2S adsorption capacity. The sorption capacity ranged from 1.2 mg/g to 121.4 mg/g. The biochar with 0.3 mm to 0.4 mm particle size possesses a maximum sorption capacity at 400 degrees C. The pH and FTIR analysis results showed that carboxylic and hydroxide radical groups were responsible for H2S sorption. These observations will be helpful in designing biochar as engineered sorbents for the removal of H2S.     

Prediction of adsorption rate of phosphate removal from wastewater with gas concrete

Gas concrete, a conventional structural material, is used to remove phosphate from wastewater. A batch study of phosphate removal from wastewater with waste particles of gas concrete has been performed. The concentration-time graphs were plotted against pH, temperature, and agitation speed, and the reaction rate equation was adapted to adsorption. The differential method was used to define reaction rate. The adsorption rates, reaction rate constants, and reaction rates were determined by tangent lines of drawn curves at different concentrations, depending on pH, temperature, and agitation speed. The adsorption rate increased with pH and temperature. The maximum effect of agitation speed on the adsorption rate was observed at 150 rpm. The activation energy of reaction and the pre-exponential factor were calculated using the Arrhenius equilibrium equation. The zeta potentials of waste gas concrete were determined at various pH values. The surface area of gas concrete was obtained using BET apparatus as 22 m2/g. The composition of gas concrete was determined by X-ray diffractometry. The results indicate that gas concrete is an effective adsorbent to remove phosphate from wastewater.     

污泥基活性炭吸附Cu（2＋）的应用研究

以城市污水处理厂剩余污泥为原料,以ZnCl2为活化剂制取污泥基活性炭。以此污泥基活性炭为吸附剂,对含Cu2＋的废水进行了吸附实验研究。考察了溶液pH值、Cu2＋的起始浓度对Cu2＋离子吸附量的影响;利用等温吸附实验作出吸附等温线,并考察了污泥基活性炭吸附剂吸附Cu2＋的动力学方程。实验结果表明,污泥基活性炭对Cu2＋具有良好的吸附性能。吸附的最佳pH值为5;吸附符合Langmuir和Freundlich吸附等温方程,吸附为优惠吸附,吸附量随着吸附质溶液浓度的增加而增大;吸附平衡时间为4 h,吸附动力学符合二级动力学方程。     

低温等离子体氧化水中难降解有机物研究

实验将介质阻挡放电与电晕放电组合在同一个反应器内,实验废水为直接大红染料溶液,将高压电极上通人50 Hz交流高压电,介质阻挡放电系统的电极间距为30 mm、电晕放电系统电极间距为25 mm、电源电压20 kV,利用常压空气中形成的雾化水电极介质阻挡放电/电晕放电低温等离子体及其活性基团作用于难降解有机物分子.实验分析了...     

有机废气吸附净化处理的新型工艺研究

简要介绍了挥发性有机废气的来源、分类及其对人体和环境的危害，以及盐城市部分企业近年来的产生和排放状况。较详细地论述了吸附净化处理技术用于废气中挥发性有机化合物的去除和回收研究工艺与特点，阐明了目前有机废气的净化处理方向。