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371.
372.
Jiajie He Clifford R. Lange Mark Dougherty 《Process Safety and Environmental Protection》2009,87(6):401-405
Annual ryegrass (Lolium perenne L.) is an important cool-season forage grass in the southeastern US. Since large portions of soils in this region are too acidic for optimum ryegrass production, there exists an opportunity to use lime mud waste from numerous regional pulp and paper mills as an agricultural liming material. In this study, four lime mud application rates, 2.25 (L1), 4.51 (L2), 9.01 (L3), and 22.50 (L4) ton ha−1, dry weight basis, and a control (L0) were evaluated for response to ryegrass growth during the first 6 weeks to estimate an optimum application range over the testing soil for future field test. Results indicated that applied lime mud slowed ryegrass germination and seedling emergence, with differences of whole plant length among treatments L0–L4 significant only during the first three weeks. Differences of whole plant dry weight among treatments L0–L4 reduced thereafter. The initial soil pH increase due to the lime mud application dropped in treatments L1–L4 by the end of the 6-week experiment. The optimum lime mud application range was estimated between L2 and L3, which provided higher ryegrass yields (kg ha−1) of 84 and 80 over 77 of the control and complied with the Code of Federal Regulation, CFR 40 Part 503 for land application. 相似文献
373.
Background Olive mill wastewater (OMW) generated by the olive oil extracting industry is a major pollutant, because of its high organic
load and phytotoxic and antibacterial phenolic compounds which resist biological degradation. Mediterranean countries are
mostly affected by this serious environmental problem since they are responsible for 95% of the worldwide oliveoil production.
There are many methods used for OMW treatment, such as adsorption, electro coagulation, electro-oxidation, biological degradation,
advanced oxidation processes (AOPs), chemical coagulation, flocculation, filtration, lagoons of evaporation and burning systems,
etc. Currently, there is no such economical and easy solution. The aim of this study was to evaluate the feasibility of decolourization
and removal of phenol, lignin, TOC and TIC in OMW by UV/H2O2 (AOPs). The operating parameters, such as hydrogen peroxide dosage, times, pH, effect of UV and natural sunlight were determined
to find the suitable operating conditions for the best removal. Moreover, there is no study reported in the literature related
to the use of UV/H2O2 and lime together in OMW treatment.
Methods OMW was obtained from an olive-oil producing plant (Muğla area of Turkey) which uses a modern production process. No chemical
additives are used during olive oil production. This study was realised by using two different UV sources, while taking the
time and energy consumption into consideration. These two sources were mercury lamps and natural sunlight. Before starting
AOPs experiments, one litre of OMW was treated by adding lime until a pH of 7.00. Then, 100 ml was taken from each sample,
and 1 to 10 ml of a 30% H2O2 (Riedel-deHaen) solution was added. These solutions in closed vessels were laid in the natural sunlight for a week and their
compositions and colour changes were analysed daily by UV-Vis spectrophotometer. At the end of the one-week period, they were
treated with lime. In this study, the effect of changes in the initial pH, times and H2O2 concentrations on removal was investigated. At the end of all experiments, changes in colour, phenol, lignin, TOC and TIC
concentrations were analysed according to standard methods.
Results and Discussion In the samples exposed to natural sunlight and having an H2O2/OMW ratio of 3 ml/100 ml, a significant colour removal was achieved approximately 90% of the time at the end of 7 days. When
the same samples were treated with lime (pH: up to 7), 99% efficiency was achieved. When phenol and lignin removals were examined
in the same concentration, phenol and lignin removal were found 99.5%, 35%, respectively. However, for maximum lignin removal,
more use of H2O2 (10 ml H2O2/100 ml OMW) was found to be necessary. Under these conditions, it was found that lignin can be removed by 70%, but to 90%
with lime, at the end of a seven-day period. Rate constants obtained in the experiments performed with direct UV were found
to be much higher than those of the samples exposed to natural sunlight (ka
lignin
= 0.3883 ≫ kb
lignin
= 0.0078; ka
phenol
= 0.5187 ≫ kb
phenol
= 0.0146). Moreover, it should be remembered in this process that energy consumption may induce extra financial burden for
organisations.
Conclusions It was found, in general, that colour, lignin, total organic carbon and phenol were removed more efficiently from OMW by using
H2O2 UV and lime OMW. Moreover, in the study, lime was found to contribute, both initially and after radical reactions, to the
efficiency to a great extent.
Recommendations and Perspectives Another result obtained from the study is that pre-purification carried out with hydrogen peroxide and lime may constitute
an important step for further purification processes such as adsorption, membrane processes, etc. 相似文献
374.
A five-stage sequential extraction procedure was used to fractionate heavy metals (Cd, Cu, Pb, Cr, Zn, Fe, Mn, Ni, Co, As,
V and Ba) in a biosludge from the biological wastewater treatment plant of Stora Enso Oyj Veitsiluoto Mills at Kemi, Northern
Finland, into the following fractions: (1) water-soluble fraction, (2) exchangeable fraction, (3) easily reduced fraction,
(4) oxidizable fraction, and (5) residual fraction. The biosludge investigated in this study is a combination of sludge from
the primary and secondary clarifiers at the biological wastewater treatment plant. Extraction stages (2)–(4) follow the protocol
proposed by the Measurements and Testing Program (formerly BCR Programme) of the European Commission, which is based on acetic
acid extraction (stage 2), hydroxylamine hydrochloride extraction (stage 3), and hydrogen peroxide digestion following the
ammonium acetate extraction (stage 4). The residual fraction (stage 5) was based on digestion of the residue from stage 4
in a mixture of HF + HNO3 + HCl. Although metals were extractable in all fractions, the highest concentrations of most of the metals occurred in the
residual fraction. From the environmental point of view, it was notable that the total heavy metal concentrations in the biosludge
did not exceed the maximal allowable heavy metal concentrations for sewage sludge used in agriculture, set on the basis of
environmental protection of soil by European Union Directive 86/278/EEC, and by the Finnish legislation. The Ca (98.6 g kg−1; dry weight) and Mg (2.2 g kg−1; dry weight) concentrations in the biosludge were 62 and 11 times higher than the typical values of 1.6 and of 0.2 g kg−1 (dry weight), respectively, in arable land in Central Finland. The biosludge had a slightly alkaline pH (∼8.30), a high loss-on-ignition
value (∼78%) and a liming effect of 10.3% expressed as Ca equivalents (dry weight). This indicates its potential as a soil
conditioner and improvement agent, as well as a pH buffer. 相似文献
375.
In this study, recalcitrant total phenol (TPh) and organic matter removal were investigated at olive mill wastewater (OMW) in sequential Coagulation and Fenton system. This study focused on different operational parameters such as pH, H2O2, and Fe2+ dosages, and [Fe2+]/[H2O2] ratios. The optimum conditions were determined as; pH = 3; [Fe2+] = 2.5 g/L; [Fe2+]/[H2O2] = 2.5. A higher treatment efficiency was achieved at sequential Coagulation and Fenton system (COD, 65.5%) and TPh, 87.2%), compared to coagulation process (COD, 51.4%; total organic carbon (TOC), 38.6% and total nitrogen (TN) 52.1%). This study demonstrated that the Coagulation and Fenton process has a potential for efficient removal of phenolic pollutants from wastewater. 相似文献
376.
Seok-jin Hong Yoon-sil Choi Kyoung-ryun Kim Joon-gu Kang Gil-jong Oh Tak Hur 《Resources, Conservation and Recycling》2011,55(12):1206-1213
The flows of paper are analyzed throughout the papermaking processes, with the year 2007 and Korea defined as the system boundaries. In practice, the statistical data on the production, import and export of paper or pulp can be collected with relative ease from the government and industrial associations. However, the input data regarding the volumes of pulp and wastepaper used in different paper products, such as newsprint, printing papers, sanitary and household papers, specialty papers, and corrugating board base, are difficult to obtain because such information is generally kept confidential in the course of corporate operations.The production processes of paper products in Korea are modeled using information on raw materials, their compositions and production yields of products in order to identify and quantify the amounts of pulp and wastepaper used in each paper product. The material flows of paper are then analyzed based on the calculation model derived from the correlation of input and output flows between the individual processes throughout the entire paper lifecycle. Accuracy analysis using both mean absolute error (MAE) and mean absolute percent error (MAPE) is conducted to verify the amounts of pulp and wastepaper calculated from the proposed model against the volumes of domestically consumed pulp and wastepaper provided in the national statistics. Although the calculated values for the past (i.e., the 1980s and 1990s) differ to some degree from the statistical values, the data for the 2000s have a relatively higher level of accuracy, with the MAPE of the total pulp and recycling volume at 5.39% and 5.30%, respectively, thus validating the adequacy of the proposed modeling method. The proposed calculation model can be effectively used in the material flow analysis (MFA) of paper to reduce the burden of data collection and obtain relatively accurate results. 相似文献
377.
Advanced lignin-acrylamide water treatment agent by pulp and paper industrial sludge:Synthesis, properties and application 总被引:1,自引:0,他引:1
Hongyan Rong Baoyu Gao Yanxia Zhao Shenglei Sun Zhonglian Yang Yan Wang Qinyan Yue Qian Li 《环境科学学报(英文版)》2013,25(12):2367-2377
A novel flocculant LA (lignin-acrylamide polymer), which was used as aid for aluminum sulfate and polyaluminum chloride in this study, was prepared by grafting acrylamide onto lignin that deriving from pulp and papermaking sludge. Physicochemical properties of LA were measured by X-ray photoelectron spectroscopy and scanning electron microscopy. The experimental outcome indicated acrylamide was grafted onto the lignin backbone successfully. The effects of LA addition were evaluated on coagulation performance and floc characteristics as a function of aluminum (Al) dosage, such as floc size, growth rate, strength and recoverability. Effects of different dosing sequences, Al dosed first and LA dosed first, were also investigated. LA used as coagulant aid markedly enhanced the removal efficiency of turbidity and dissolved organic carbon, especially at low Al dosages. The dissolved organic carbon removal efficiencies of aluminum sulfate and polyaluminum chloride at the Al dosage range selected in this study were improved more than 30% and 5% by LA, respectively. LA dramatically enlarged floc size and it was in the order: Al dosed first 〉 LA dosed first 〉 Al. Floc strength and recoverability were also improved by LA. LA played a significant role in charge neutralization, adsorption and bridging in floc formation. 相似文献
378.
Sequential (anaerobic/aerobic) biological treatment of Dalaman SEKA Pulp and Paper Industry effluent 总被引:5,自引:0,他引:5
Ulas Tezel Engin Guven Tuba H. Erguder Goksel N. Demirer 《Waste management (New York, N.Y.)》2001,21(8):717-724
In the pulp and paper industry, lignin and other color compounds are removed by chemical agents in bleaching process. Use of chlorine-based agents results in production of degradation products which include various chloro-organic derivatives. Since these new compounds are highly chlorinated, they cause a problem in the treatment of pulp and paper industry wastewaters. Chemical precipitation, lagooning, activated sludge, and anaerobic treatment are the processes used for treating pulp and paper effluents. Furthermore, a combination of these processes is also applicable. In this study, the effluent of Dalaman SEKA Pulp and Paper Industry was examined for its toxic effects on anaerobic microorganisms by anaerobic toxicity assay. Additionally, this wastewater was applied to a sequential biotreatment process consisting of an upflow anaerobic sludge blanket as the anaerobic stage and a once-through completely mixed stirred tank as the aerobic stage. Results indicated that: (1) Dalaman SEKA Pulp and Paper Industry wastewater exerted no inhibitory effects on the anaerobic cultures under the studied conditions, and (2) application of a sequential biological (anaerobic/aerobic) system to treat the Dalaman SEKA Pulp and Paper Industry wastewater resulted in approximately 91% COD and 58% AOX removals at a HRT of 5 and 6.54 h for anaerobic and aerobic, respectively. 相似文献
379.
380.
造纸废水可生化性差,处理困难,对其进行生化前预处理具有重要意义。采用无机高分子混凝剂和有机混凝剂联合处理,有助于提高混凝效果。实验研究了两种造纸废水混凝处理的影响因素和处理效果,在实验室条件下进行了单因素实验分析,确定了最佳投药量,得到的结果分别是:卫生纸车间废水为聚合氯化铝(PAC)75 mg/L,阳离子聚丙烯酰胺(PAM)0.075 mg/L;板纸车间废水为聚合氯化铝(PAC)350 mg/L,阳离子聚丙烯酰胺(PAM)0.125 mg/L。在此工况下,卫生纸车间废水COD的去除率达到了62.12%,色度去除率达到92.12%,SS去除率达到了95.36%;板纸车间废水COD的去除率达到了44.03%,最佳色度去除率达到90.25%,SS去除率达到93.18%。提高了废水的可生化性,为后续生物处理创造了条件。 相似文献