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1.
孔涛  何新胜 《环境科学》1993,14(B09):67-68
针对国内中小碱法纸厂特点,开发区别于燃烧法碱回收原理的简易碱回收方法;开发区别于酸析木素工艺的木素回收新工艺;同时辅助性开发为草浆燃烧法碱回收系统服务的快速除硅工艺.总体达到具有投资低、有相当经济效益,不仅回收碱而且同时回收木素的效果.另外为传统碱回收方法提供预处理脱硅技术支持.  相似文献   

2.
胡培铎  陈静 《环境科学》1993,14(B09):24-25
我国现有5000多个制浆造纸厂,配备碱回收装置的仅55个企业。据近年来统计,草浆每年耗碱76.82万t,只回收5.69万t,回收率仅为2.4%,其余绝大部分随废水排走,“一个纸厂污染一条河”.我国碱法草浆造纸行业碱回收困难的主要原因是“硅干扰”.多年来,因草浆黑液除硅这一关键技术未能突破,  相似文献   

3.
碱法草浆黑液酸析回收木质素   总被引:12,自引:0,他引:12  
本文研究了加酸沉淀回收碱法草浆黑液中木质素的工艺,实验了pH值、水温和加酸速度对本质素收率的影响.  相似文献   

4.
研究了 2种不同的碱回收方法—隔膜电解法和物理化学法回收草浆黑液中残碱的可行性及处理效果 ,并进行了回收碱液蒸煮纸浆的实验。实验结果表明 ,两种回收方法均具有较高的碱回收率—分别达到 94%和 6 0 %以上 ,所制纸浆与原液浆比较性能也无明显差异 ,且 2种方法均有操作简便、设备一次性投资少、处理黑液效果较好等特点 ,为中小型造纸厂解决黑液污染问题提供了新的技术思路  相似文献   

5.
穆莹 《环境保护》2000,(3):47-48
碱法制浆黑液污染治理的根本出路是碱回收。燃烧是碱回收的主要技术手段。本文从碱回收理论与应用实践结合出发,对燃烧法草浆碱回收的工艺,设备及运行条件进行了具体分析,并提出了有针对性的改进措施,以供参考。  相似文献   

6.
介绍碱法草浆黑液采用膜技术处理的各种方案,着重介绍了碱法草浆黑液资源化全回收技术并提出了新的技术方案,该方案是先用硫酸中和酸析黑液中的木质素,或用纳滤方案回收木质素,然后采用双极膜电渗析法回收已去除木质素的黑液中的酸和碱,最后经蒸发和喷雾干燥回收其中的糖、其他营养成分及大部分水,达到无污染排放的目的。该方案碱回收率在50%~80%,取决于黑液中碱的浓度,回收1 t碱的耗电量低于2 500 kW.h。该法的基本投资比同规模碱回收法节省60%以上,具有较好的经济效益。  相似文献   

7.
指出了碱电精制直馏柴油技术存在的问题,对复合溶剂法(SW-1-氨法)精制直馏柴油进行探索试验,介绍了复合溶剂法工艺流程、特点,分析了碱电精制和复合溶剂两种方法的效果和操作成本.对比说明复合溶剂精制直馏柴油并回收环烷酸工艺是极有前景的。  相似文献   

8.
我国造纸工业的特点是草浆多,木浆少,小厂多,大厂少,分散,因此,废液治理难度较大.据统计全国有纸厂约6000个,碱法制浆每年约耗用烧碱100万t,设有碱回收装置的约62家,设计能力40万t,实际每年可回收约35万t,回收35万t碱的同时,产生白泥约56万t,目前回收白泥量约18万t,  相似文献   

9.
黑液电渗析碱回收的研究   总被引:9,自引:0,他引:9  
针对造纸黑液的碱性及污染严重的特点,采用单阳膜电渗析法对黑液中的碱加以回收.并研究了电渗析操作中如电流密度,黑液浓度,温度等因素的影响.综合考虑得到电流密度350A/m2,电流效率85%~90%,碱回收率70%~75%,耗电量5000~6000KWH/t碱的结论  相似文献   

10.
本技术包括污水回用,酶法脱毛替代传统灰浆脱毛,烧碱浸碱替代石灰硫化钠浸碱,碱法回收废铬液及混合脂肪酸法回收回软工段油脂等五个技术要素。前四个技术要素互为协高、互为关联,构成A技术单元。混合脂肪酸 法回收油脂单独构成B技术单元。  相似文献   

11.
The selective recovery of copper from strongly acidic wastewater containing mixed metal ions remains a significant challenge. In this study, a novel reagent zinc dimethyldithiocarbamate (Zn(DMDC)2) was developed for the selective removal of Cu(II). The removal efficiency of Cu(II) reached 99.6% after 120 min reaction at 30°C when the mole ratio Zn(DMDC)2/Cu(II) was 1:1. The mechanism investigation indicates that the Cu(DMDC)2 products formed as a result of the displacement of Zn(II) from the added Zn(DMDC)2 by Cu(II) in wastewater, due to the formation of stronger coordination bonds between Cu(II) and the dithiocarbamate groups of Zn(DMDC)2. Subsequently, we put forward an innovative process of resource recovery for strongly acidic wastewater. Firstly, the selective removal of Cu(II) from actual wastewater using Zn(DMDC)2, with a removal efficiency of 99.7%. Secondly, high-value CuO was recovered by calcining the Cu(DMDC)2 at 800°C, with a copper recovery efficiency of 98.3%. Moreover, the residual As(III) and Cd(II) were removed by introducing H2S gas, and the purified acidic wastewater was used to dissolve ZnO for preparation of valuable ZnSO4·H2O. The total economic benefit of resource recovery is estimated to be 11.54 $/m3. Accordingly, this study provides a new route for the resource recovery of the treatment of copper-containing acidic wastewater.  相似文献   

12.
化工产业是天津滨海新区重要的支柱产业,该行业废水因污染种类复杂,具有高盐、高毒、难降解等特点,是滨海新区污染物控制的主要威胁。通过对滨海某化工区实际废水进行几种主流预处理技术及其组合工艺的研究,明晰了其在实验条件下各自的特点,验证了其实际处理效果,进一步掌握了其反应过程中的特性,为研究后续的示范工程应用及大规模推广打下基础。实验表明,制药废水经内电解处理后毒性削减率最高可达到46%,对化学合成废水有较好的去毒效果,该技术可有效地提高制药废水的可生化性;光催化氧化对苯胺和氯苯的最佳降解条件分别是15 g/L TiO(23 h)及17.5 g/L TiO2;负载型纳米铁和纳米四氧化三铁催化剂分别适合极酸和中性、偏碱性条件,催化效率高,COD去除效果好。  相似文献   

13.
半导体行业是我国大力发展的高精尖产业,废水产生量大、再生处理难度高.半导体行业废水再生处理过程中,反渗透(reverse osmosis, RO)是重要的污染物去除单元,但面临的膜污堵问题严重影响了其效率与经济性.本文梳理了半导体行业废水的种类与典型污染物,总结了半导体行业废水导致反渗透膜污堵的主要机制及控制手段,提出了针对半导体行业废水特点的膜污堵控制策略.半导体生产的不同工序会产生多种废水,包括含氟废水、含磷废水、含氨废水、重金属废水、有机废水与酸碱废水等.废水中污染物种类多且可生化性普遍较差.通常,不同种类废水分类经分质收集后,进行相应的预处理,之后部分合流处理并进入RO系统.半导体行业废水中的金属离子或氟离子易在反渗透膜面形成无机结垢,表面活性剂易形成有机污堵.反渗透膜污堵可通过预处理、膜清洗与运行条件调控等手段进行控制,如超滤、EDTA清洗剂与pH调节等,但大部分现有手段对半导体行业废水造成的污堵控制能力有限.建议未来开发针对关键污染物的预处理技术与定制化的膜清洗方案;并结合半导体生产工序,提出针对污染物关键相互作用关系的废水收集与再生处理整体策略.  相似文献   

14.
综述了近年来常用的炼化废碱液处理方法及优缺点,针对现有炼化废碱液特点,提出了相应的废碱液处理优化方案。  相似文献   

15.
In order to purify oil recovery wastewater from polymer flooding (ORWPF) in tertiary oil recovery in oil fields, advanced treatment of UV/H2O2/O3 and fine filtration were investigated. The experimental results showed that polyacrylamide and oil remaining in ORWPF after the conventional treatment process could be effectively removed by UV/H2O2/O3 process. Fine filtration gave a high performance in eliminating suspended solids. The treated ORWPF can meet the quality requirement of the wastewater-bearing polymer injection in oilfield and be safely re-injected into oil reservoirs for oil recovery.  相似文献   

16.
Strongly acidic wastewater produced in nonferrous metal smelting industries often contains high concentrations of Ni(II), which is a valuable metal. In this study, the precipitation of Ni(II) from strongly acidic wastewater using sodium dimethyldithiocarbamate (DDTC) as the precipitant was evaluated. The effects of various factors on precipitation were investigated, and the precipitation mechanism was also identified. Finally, the nickel in the precipitates was recovered following a pyrometallurgical method. The results show that, under optimised conditions (DDTC:Ni(II) molar ratio = 4:1; temperature = 25 °C), the Ni(II) removal efficiency reached 99.3% after 10 min. In strongly acidic wastewater, the dithiocarbamate group of DDTC can react with Ni(II) to form DDTCNi precipitates. Further recovery experiments revealed that high-purity NiO can be obtained by the calcination of DDTCNi precipitates, with the nickel recovery efficiency reaching 98.2%. The gas released during the calcination process was composed of NO2, CS2, H2O, CO2, and SO2. These results provide a basis for an effective Ni(II) recovery method from strongly acidic wastewater.  相似文献   

17.
通过试验研究,在停留时间为8h左右,生物曝气滤池(BAF)工艺对碱水二级处理效率高,碱水经过处理后,石油类的平均去除率达到89%,硫化物的平均去除率达到99%。研究结果表明,BAF是一种高效的处理方法,适合炼油厂碱水的净化治理。  相似文献   

18.
Experimental data are presented to test and validate a kinetic model for the oxidation of 2-chlorophenol wastewater by photo-assisted Fenton process. The data showed that this process had produced good effects under acidic conductions. Up to 90% 2-chlorophenol was removed after 90-minute reaction time with H2O2 of 25% CODCr. in, while in UV/H2O2 system ordy 16.8% 2-chlorophenol was removed after one hour treatment. The optimal pH in this reaction occurred between pH 3.0 and pH 4.0. The reaction kinetics for photo-assisted Fenton process experimented in this research was investigated. Kinetic models were proposed for the treatment of 2-chlorophenol wastewater. The reaction was found to follow the 2nd order. The equations of reaction kinetics are as follows:-d[RH]/dt=KRH[RH][H2O2]0exp(-KH2o2t);-d[CODCr]/dt=KCODCr[CODCr][H2O2]0exp(-K′t).The prediction of the models was found to be in a good agreement with experimental results, thus confimfing the proposed reaction mechanism.  相似文献   

19.
2-萘酚生产对环境的影响及废水处理工艺研究   总被引:5,自引:0,他引:5  
分析了2-萘酚生产现状、市场形势及污水特点,在总结当前2-萘酚生产废水处理工艺研究状况的基础上,提出了处理2-萘酚污水的双效蒸发-冷凝结晶工艺。该工艺回收2-萘磺酸钠并加以再利用,回收率可达到50%以上,余下的浓缩液可用于生产硫酸钠。实践表明,经该工艺处理的排放污水,其净化程度达到国家污水排放二级标准。  相似文献   

20.
钢渣对酸性含Ni(Ⅱ)废水的吸附-中和作用   总被引:1,自引:0,他引:1  
以碱性钢渣为水处理材料,研究了其吸附、中和酸性含Ni(Ⅱ)废水的工艺过程和机理。结果表明:在钢渣粒度小于2 mm、用量10 g/L、温度25℃、搅拌强度100 r/min条件下钢渣与Ni(Ⅱ)浓度200 mg/L、pH值4.8的废水反应8 min,可使废水中Ni(Ⅱ)浓度降低到0.25 mg/L,pH值升高到7.2,达到GB8978-1996《污水综合排放标准》的要求。钢渣对酸性废水中Ni(Ⅱ)的吸附符合Langmuir等温吸附式,其饱和吸附量达37 mg/g,反应包括钢渣中碱性物质的水解、Ni(Ⅱ)生成Ni(OH)2沉淀、生成的Ni(OH)2沉淀吸附于钢渣表面等几个过程。X射线衍射分析证明钢渣表面吸附了Ni(OH)2沉淀物。  相似文献   

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