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农药化工厂生产苯肼、苯唑醇、乙基氯化物过程排放的废水是高氯难生物降解有机废水,采用三辛胺作萃取剂,用液-液萃取处理,三辛胺与水中Cl-离子形成萃合物而使Cl-转移到有机相.再经高效絮凝处理后,CODCr总去除率达89.8%,Cl-总去除率达83.2%,BOD/COD比从0.02上升到0.34,可生化性大幅度提高.
废水再经河水稀释进A/O池生化处理3d后,可达标排放.负载萃取液用5%NaOH水溶液反萃取.由于萃取剂回用降低了处理费用. 相似文献
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用HL离心萃取器处理含对硝基酚废水的研究 总被引:1,自引:0,他引:1
溶剂萃取法是目前回收处理含高浓度对硝基酚废水的有效方法。选用QH-1为萃取剂,采用HL离心萃取器对含对硝基酚废水的处理进行了实验研究。实验结果表明,对于对硝基酚硝酸溶液-QH-1体系,对硝基酚的分配比是1103.4,用Φ20mmHL离心萃取器处理对硝基酚废水时,在合适的操作条件下,单级传质级效率E和三级串联萃取率ρ都可达99%以上,三级串联的反萃率也可达98%以上。 相似文献
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萃取技术分离工业废水中的苯胺 总被引:1,自引:0,他引:1
研究以硝基苯为萃取剂,25℃下通过盐析萃取法回收工业废水中苯胺。以静态分批实验考察了废水酸度、初始苯胺浓度、萃取剂与废水比(油水比)、萃取级数、无机盐种类(NaCl,KCl,Na2SO4,CaCl2,K2SO4)和浓度对苯胺萃取率的影响,获得了最佳操作工艺条件。实验结果表明,硝基苯盐析萃取技术可以有效回收废水中苯胺,且高pH和溶剂比有利于苯胺萃取,随着无机盐浓度的增加苯胺回收率增加。在适宜的条件下,通过盐析作用,经过五级萃取苯胺萃取率接近100%。 相似文献
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采用络合萃取法处理5-氯水杨酸生产废水,研究了萃取过程中PH、络合剂、稀释剂等对废水革取效果的影响。通过比较,确定以EPT-1为络合剂。试验表明,pH<1.5,按废水:络合剂:稀释剂-100:30:70的比例投加,可取得较好效果。萃取剂连续使用15次,废水的CODCr去除率并无显著下降。多次萃取后萃取剂经氢氧化钠溶液反萃取再生,即可回收萃取剂。 相似文献
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为了去除并回收兰炭废水中的高浓度挥发酚类物质,实验研究了甲基异丁酮溶剂在不同条件下对兰炭废水中挥发酚的萃取及回收效果。结果表明,萃取时间为10 min,温度为35℃,p H低于8.0,萃取体积比(萃取剂体积/兰炭废水体积)在大于1∶5时,经过萃取后废水中挥发酚浓度由6 385 mg/L降至230 mg/L,去除率高达96.4%,有效减轻了后续生化处理的负担。而萃取剂经过蒸馏分离后,挥发酚的回收率可达95%以上,甲基异丁酮的损耗率为0.18%~0.2%。实验表明,甲基异丁酮是一种可以长期循环使用的工业萃取剂,显示了良好的应用前景。 相似文献
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磷酸三丁酯络合萃取邻氨基苯酚及工业废水预处理研究 总被引:1,自引:2,他引:1
根据络合萃取的原理,考虑了萃取剂与稀释剂之间的作用,选择磷酸三丁酯(TBP)为萃取剂,以正辛醇和氯仿为极性稀释剂、四氯化碳和煤油为非极性稀释剂,对邻氨基苯酚(OAP)稀溶液进行了探讨,讨论了体系的pH、TBP的浓度、稀释剂种类对萃取分配比(D)的影响.结果表明,TBP主要通过与OAP的中性分子键合作用实现萃取;D值的变化与中性分子的摩尔分数有关,pH是影响D的主要因素;稀释剂的极性对OAP的萃取影响较大,在萃取剂体积分数为10%~30%时,其萃取能力为TBP-正辛醇>TBP-煤油>TBP-四氯化碳>TBP-氯仿;在萃取剂体积分数为30%~50%时,萃取能力为TBP-煤油>TBP-正辛醇>TBP-四氯化碳>TBP-氯仿.进而以30%TBP-煤油为萃取剂,对工业含OAP废水进行了错流萃取实验.实验表明,该方法可以对工业OAP废水进行有效的(94.7%)预处理;工业废水中的甲醇、乙醇,对萃取有较大影响. 相似文献
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Chromated copper arsenate (CCA)-treated wood was liquefied with polyethylene glycol/glycerin and sulfuric acid. After liquefaction, most CCA metals (98% As, 92% Cr, and 83% Cu) were removed from liquefied CCA-treated wood by precipitation with calcium hydroxide. The original CCA-treated wood and liquefied CCA-treated wood sludge were fractionated by a modified Community Bureau of Reference (BCR) sequential extraction procedure. The purpose of the BCR-sequential extraction used in this study was to examine the availability of CCA metals in treated wood for reuse. Both As and Cr had a slightly higher concentration in the sludge sample than in original CCA-treated wood. The sequential extraction showed that As and Cr were principally existed in an oxidizable fraction (As, 67%; Cr, 88%) in original CCA-treated wood. Only 1% of both As and Cr were extracted by hot nitric acid with the last extraction step. The distribution of As and Cr changed markedly in liquefied CCA-treated wood sludge.The amount of As in the exchangeable/acid extractable fraction increased from 16% to 85% while the amount of Cr increased from 3% to 54%. Only about 3% of As was present in the oxidizable fraction. However, there was still about 34% of Cr in the same fraction. Based on these results from sequential extraction procedures, it can be concluded that the accessibilities of CCA metals increase markedly by the liquefaction–precipitation process. 相似文献
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Shoujun Yuan Qiquan Wang Scott R. Yates Nyles G. Peterson 《Journal of environmental science and health. Part. B》2013,48(7):612-620
Oxytetracycline (2-(amino-hydroxy-methylidene)-4-dimethylamino-5,6,10,11,12a-pentahydroxy-6-methyl-4,4a,5,5a-tetrahydrotetracene-1,3,12-trione) is a major member of the tetracycline antibiotics family of which are widely administered to animals in concentrated animal feeding operations for purposes of therapeutical treatment and health protection. With the disposal of animal manure as fertilizer into agricultural land, tetracyclines enter the environment. However, tetracyclines chelate with multivalent cations and proteins, resulting in low extraction efficiencies from animal manure for tetracycline residue analysis. In this study an efficient extraction method for oxytetracycline from steer manure using methanol/water solution amended with chelating organic acid was developed for the analysis of high performance liquid chromatography. The effect of species and amount of amendment acids, shaking time, methanol/water ratio, manure weight, and repeated times of extraction was investigated. It was optimized to amend 2.5 g citric acid and 1.1 g oxalic acid with 10.0 g manure sample in a 50-ml centrifuge tube and extract with 15 ml methanol/water (9:1 in volume) by vigorously shaking for 30 min in a reciprocating shaker. After centrifugation at 11,000 rpm, supernatant is collected. Sample was extracted for a total of 3 times. The developed extraction method was further applied to extract oxytetracycline from fresh and aged cow manure, swine and poultry manure, and soil. Satisfactory recoveries ranging from (84.1 ± 2.4) % to (102.0 ± 3.1) % were obtained, demonstrating that the optimized extraction method is robust for oxytetracycline from different manure sample matrixes. 相似文献
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In the present study biosorption technique, the passive accumulation of metals by biomass, is used for the removal of nickel from aqueous medium. The brown algae, Sargassum sp., in its natural and acid treated forms are used as a low cost sorbent. The adsorption characteristics of nickel on Sargassum sp. are evaluated as a function of time, pH, adsorbent dosage and initial concentration of nickel. The equilibrium adsorption data are fitted to Freundlich and Langmuir adsorption isotherm models and the model parameters are evaluated. Both the models represent the experimental data satisfactorily. The adsorption follows Lagergren first order kinetic model. The monolayer adsorption capacities of natural and acid treated forms of algae as obtained from Langmuir adsorption model are found to be 181 and 250mg g(-1) respectively. 相似文献
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Factors controlling the transport of geogenically-derived arsenic from a coastal acid sulfate soil into downstream sediments are identified in this study with both solid-phase associations and aqueous speciation clearly critical to the mobility and toxicity of arsenic. The data from both sequential extractions and X-ray adsorption spectroscopy indicate that arsenic in the unoxidised Holocene acid sulfate soils is essentially non-labile in the absence of prolonged oxidation, existing primarily as arsenopyrite or as an arsenopyrite-like species, likely arsenian pyrite. Anthropogenically-accelerated pedogenic processes, which have oxidised this material over time, have greatly enhanced the potential bioavailability of arsenic, with solid-phase arsenic almost solely present as As(V) associated with secondary Fe(III) minerals present. Analyses of downstream sediments reveal that a portion of the arsenic is retained as a mixed As(III)/As(V) solid-phase, though not at levels considered to be environmentally deleterious. Determination of arsenic speciation in pore waters using high performance liquid chromatography/Inductively Coupled Plasma-Mass Spectrometry shows a dominance of As(III) in upstream pore waters whilst an unidentified As species reaches comparative levels within the downstream, estuarine locations. Pore water As(V) was detected at trace concentrations only. The results demonstrate the importance of landscape processes to arsenic transport and availability within acid sulfate soil environments. 相似文献
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Due to their potential toxicity and odourous nature, the residual organics in municipal solid waste incinerators are recently gaining attention as an important issue of resources recovery apart from their complex mixture of organic counterpart. Studies of the organic fractions in municipal solid waste incinerator residues have been limited. In this study, extended solid-phase extraction of the water-washed bottom ash and liquid-phase extraction of the washing water were carried out with regard to bottom ash samples from three mass-burning incinerators in Taipei County (Taiwan) during four consecutive seasons of year 2008-2009. Supercritical fluid extraction and Soxtec extraction techniques along with GC-MS were successfully used to characterize the residual organics in weathered and washed bottom ashes. Supercritical fluid extraction provided the quantification of aliphatics and aromatic compounds such as hexanoic acid and benzaldehyde, respectively. Soxtec extraction was useful for qualitative analysis of aromatic and aliphatic groups in the ashes and many of which were odourous and toxic compounds. By mixing one unit weight (g) bottom ash with two unit volume (mL) water for 15 min, total organic carbon in the bottom ash was greatly reduced (e.g., from 4.1 to 1.8 wt.%). Among the removed were foul odour-causing compounds such as pyridine and quinoline derivatives, while some aromatic compounds such as 4-hydroxybenzaldehyde and low-molecular-weight aliphatics such as hexanoic acid remained. The results here suggest that washing with water can be an effective pre-treatment step for removing odour-causing and environmental concerned organics. 相似文献
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Occurrence of arsenic in brown rice and its relationship to soil properties from Hainan Island, China 总被引:3,自引:0,他引:3
Fu Y Chen M Bi X He Y Ren L Xiang W Qiao S Yan S Li Z Ma Z 《Environmental pollution (Barking, Essex : 1987)》2011,159(7):1757-1762
The acquaintance of arsenic concentrations in rice grain is vital in risk assessment. In this study, we determined the concentration of arsenic in 282 brown rice grains sampled from Hainan Island, China, and discussed its possible relationships to the considered soil properties. Arsenic concentrations in the rice grain from Hainan Island varied from 5 to 309 μg/kg, with a mean (92 μg/kg) lower than most published data from other countries/regions and the maximum contaminant level (MCL) for Asi in rice. The result of correlation analysis between grain and soil properties showed that grain As concentrations correlated significantly to soil arsenic speciation, organic matter and soil P contents and could be best predicted by humic acid bound and Fe-Mn oxides bound As fractions. Grain arsenic rises steeply at soil As concentrations lower than 3.6 mg/kg and gently at higher concentrations. 相似文献
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Soil contamination by metallic elements including lead occurs frequently. Contaminant metals in soil pose a serious risk to public health and groundwater supplies. Extraction using chelants is seen as a remediation option; however, it is often hampered by access to the contaminants that are shielded by the soil matrix. We have developed a novel extraction technique that utilizes a mildly elevated pressure in consecutive cycles of compression and decompression along with a chelating agent for the soil slurry. Complete extraction of 3300 mg/kg of Pb from soil was achieved by 100 mM of EDTA (ethylenediaminetetraacetic acid) in 10 min using 20 pressure cycles at 150 psi (10 atm). Extraction was studied according to pressure, number of pressure cycles, chelant concentration, solid content, pH, agitation, and use of consecutive washings. Heightened extraction is attributed to fracturing of the soil particles that leads to enhanced contaminant exposure to the chelating agent. 相似文献