普通过磷酸钙清洁生产工艺的研究与应用

通过实现氟硅酸循环利用，用含氟硅胶生产白炭黑，基本消除普钙生产中含氟污染物的排放，且有较好的经济效益。     

含氟烟气的净化与回收

含氟烟气是主要的大气污染物之一,本文就铝电解、磷肥工业产生的含氟烟气的一般治理方法进行了综述,各企业应因地制宜,选用技术先进、经济合理、操作简单、可有效控制污染的含氟烟气净化工艺.     

湿碱法净化回收铝电解烟气

铝电解生产过程中,散发出大量的氟化氢、含氟粉尘和沥青挥发物。这些有害物对人体危害较大,污染环境严重,必须予以治理。我厂铝电解车间采用双层厂房自然通风建筑,烟气净化系统包括地面局部排烟系统     

含氟烟气的净化与回收

含氟烟气是主要的污染物之一，本文不铝电解、磷肥工业产生的含氟烟气的一般溶理方法这，各企业应因地制宜，选用技术先进、经济合理、操作简单、可有效控制污染的含氟烟气净化工艺。     

多孔方沸石球的除氟及再生机理

利用鄂尔多斯盆地白垩系的方沸石岩样,通过提纯和改性等处理制成多孔方沸石球,用于处理含氟水。用过的方沸石球经再生处理也用于处理含氟水。实验结果表明,多孔方沸石球和再生方沸石球都有明显的除氟效果。对于100mL浓度5.00 mg/L的含氟水,多孔方沸石球较佳的水处理工艺条件为:用量3.0 g,搅拌后静置48 h。对于浓度3.00 mg/L的含氟水,一次水处理就能将F-浓度降到国家标准以内,除氟效率达60%。对于浓度5.00 mg/L的含氟水,2次水处理可以将F-浓度降到国家标准以内,除氟效率达80%。多孔方沸石球对氟离子的吸附符合Langmuir等温式,吸附速度符合斑厄姆公式。再生方沸石球对氟离子的吸附也符合Langmuir等温式,吸附速度也符合斑厄姆公式。多孔方沸石球和再生方沸石球的饱和吸附量相当,这说明用过的方沸石球经再生处理后活性基本恢复,可循环用于含氟水的处理。     

普钙生产含氟尾气治理技术的应用

介绍了云南某化工厂年产3万t普钙含氟尾气治理工程的运行现状、工艺流程和设计参数,并根据使用效果进行分析总结,通过当地环保局12年的监测数据表明,该厂含氟尾气采用喷淋塔、喷杯塔和喷淋旋流板塔处理后,不仅尾气达标排放,还副产300 t/a氟硅酸钠,实现了环境效益和经济效益的双丰收.还根据12年来工程中出现的问题提出了改进的措施和建议,供普钙行业含氟尾气治理工程设计参考.     

我国粮食含氟水平的初步调查

粮食含氟水平的调查,对于研究地氟病的病因及防治、制订环境氟、食物氟和饮水氟的卫生标准都是有意义的. 分析化学界有一种公认的观点是,报出错误的数据比没有数据更坏.因为错误的数据将使人作出错误的结论,或影响生产或不利于人民的健康.     

含氟废水处理述评

国民经济的许多部门如磷肥工业、冶金、化工、玻搪、仪表、轻工、农药、电镀、半导体、稀土及原子能工业等都有含氟废水的排放。但来自不同行业或部门的含氟废水在质的方而及量的方面都有较大的差别,加上国情不     

旋流板塔用于净化含氟废气的研究

一、前言用硫酸分解磷矿生产普通过磷酸钙(简称普钙)时,产生大量含氟废气,其反应式如下:2Ca_5F(PO_4)_3+7H_2SO_4+3H_2O=3Ca(H_2PO_4)_2·H_2O+7CaSO_4+2HF↑ (1)反应中产生的 HF 气体继续与磷矿中的 SiO_2作用,产生如下反应:4HF+SiO_2=SiF_4+2H_2O (2)SiF_4+2HF=H_2SiF_6 (3)含氟气体的逸出量主要取决于磷矿中的氟含量。在制取普钙时,矿中氟约有40%以 SiF_4的气态逸出,混合气中氟浓度约为15～20g/Nm~3,此浓度随进入系统的空气量多少而变化,但就其绝对量来说,一个年产十万吨普钙(含 P_2O_5 18%)的小型厂每年产生的含氟气体,按氟量计算约有一千吨。因此普钙     

方沸石水质净化剂的制备及其除氟研究

通过微观分析方法,在鄂尔多斯盆地白垩系钻孔岩样中首次发现方沸石类矿物.就地取材,对方沸石岩进行提纯和改性,制成多孔方沸石球,用于含氟水的处理,取得了明显的效果.对于100 mL起始浓度3 mg/L的含氟水,方沸石球较佳的水处理工艺条件为:用量1.5 g,搅拌后静置48 h,直径3 mm.对于起始浓度3 mg/L的含氟水,方沸石球一次水处理后氟离子浓度就低于国家标准值.对于起始浓度3～10 mg/L的含氟水,经方沸石球几次水处理后氟离子浓度也低于国家标准值.方沸石球对氟离子吸附等温线符合Langmuir吸附等温式,为:qe=0.243ce/1 0.433ce;吸附速度符合斑厄姆公式,为:dq/dt=4.482×10-3(qe-q)/t0.176.用过的方沸石球再生处理后活性基本恢复,多次再生后除氟效果有所下降.     

Treatment Technologies For Hazardous Wastes: Part IV A Review of Alternative Treatment Processes for Metal Bearing Hazardous Waste Streams

The U.S. Congress and the U.S. Environmental Protection Agency believe that treatment and recovery techniques should be given maximum priority when considering methods for managing the nation's generated hazardous waste. A prohibition for the disposal of certain categories of hazardous wastes either directly onto or into the land without being treated to an accepted degree prior to such disposal practice has been promulgated.¹ Wastes containing toxic metals and cyanide complexes have been selected as a group to be restricted. Due to the high generation rate associated with this category, a large capacity of waste treatment processing will be required. Existing and emerging treatment alternatives which are or have the potential to be employed for waste treatment of metal bearing wastes are presented in this paper.     

Exceptional weather in the midlands, UK, during 1988-1990 results in the rapid acidification of an upland stream

Numerous catchment studies have identified the control exerted by hydrological processes on short-term (within a year) fluctuations in surface water acidity. Because discharge is, in turn, a function of broad climate parameters, there has been growing interest in the potential impact of changing precipitation and temperature regimes on water chemistry. The exceptionally warm and arid period 1988-1990 provided an opportunity to investigate the response of an acidic catchment in the East Midlands to an extreme climate scenario. The results obtained from three years of intensive monitoring indicated that between 1988 and 1990 there was a fourfold increase of the surface-water acidity at several observation sites within the Beacon catchment, Charnwood Forest, Leicestershire. As well as providing an indication of currently extreme hydrochemical conditions which in the near future may become the norm, these observations also have a bearing on the validity of long-term predictions derived from process-orientated models.     

Treatment Technologies for Hazardous Wastes: Part 1 Treatment Alternatives for Dioxin Wastes

The 1984 Amendments to the Resource Conservation and Recovery Act (RCRA), called the Hazardous and Solid Waste Amendments, (HSWA) direct the EPA to determine if dioxin bearing wastes should be prohibited from landfills. This determination is to made by November 1986. Barring a determination by the Agency that the land disposal of dioxin wastes does not represent a threat to the environment, ot that appropriate alternative treatment technology is not available, a land disposal prohibition would go into effect at that time.¹ The purpose of this paper is to discuss the state of the art for several treatment processes for dioxin wastes that have been proposed to be used instead of land disposal for disposing of solid and liquid wastes containing dioxins.     

Effect of Oxidizing and Reducing Conditions on the Reaction of Water with Sulfur Bearing Blast Furnace Slags

The evolution of H₂S and SO₂ from hot blast furnace slags by reaction with H₂O has been found to be dependent upon the presence of O₂ or H₂ in the reaction zone as well as on the temperature. H₂ has been found to produce a small increase in H₂S and a small decrease in SO₂ emission, while O₂ has been found to produce a very great inhibiting effect on H₂S emission and only a small increase in SO₂ emission. The total emission of sulfur bearing gases is much less when H₂O + air is blown at the slag than when H₂O + Ar is blown at the slag, particularly at 1200°C and above. These effects may be useful in attempts to design systems for slag quenching which will produce less pollution.     

Uptake of soil applied paclobutrazol in mango (Mangifera indica L.) and its persistence in fruit and soil

Paclobutrazol is a plant growth regulator that is used to counter alternate bearing habit of mango (Mangifera indica L.). The uptake and persistence of paclobutrazol residues in mango fruits and soil respectively, was studied following its application at tree basin soil @5 and 10 g a.i. per tree for three consecutive years. Residues of paclobutrazol were found in unripe mango fruits at levels below permissible level while the same was generally not detected in fully mature mango fruits ready for harvest. There was no effect of consecutive yearly applications on the amount of paclobutrazol residues in mango fruit. However, the residues of paclobutrazol were found in tree basin soil (0-15 cm) at the end of each season and there was a small increase in the amount of residues corresponding to the number of yearly applications that had been made. GC-MS analysis confirmed that the sample peaks obtained corresponded to paclobutrazol residues present in mango and soil.     

荧光渗透乳化油废水处理技术的研究

采用“破乳 -絮凝 -砂滤 -吸附”法对荧光渗透乳化油废水进行处理 ,结果表明 ,在适宜的处理条件下 ,该法可有效地去除水中的COD、油和色度 ,出水的 pH、COD、油和色度均达到国家一级排放标准     

Anaerobic treatment of army ammunition production wastewater containing perchlorate and RDX

Perchlorate is an oxidizer that has been routinely used in solid rocket motors by the Department of Defense and National Aeronautics and Space Administration. Royal Demolition Explosive (RDX) is a major component of military high explosives and is used in a wide variety of munitions. Perchlorate bearing wastewater typically results from production of solid rocket motors, while RDX is transferred to Army industrial wastewaters during load, assemble and pack operations for new munitions, and hot water or steam washout for disposal and deactivation of old munitions (commonly referred to as demilitarization, or simply demil). Biological degradation in Anaerobic Fluidized Bed Reactors (AFBR), has been shown to be an effective method for the removal of both perchlorate and RDX in contaminated wastewater. The focus of this study was to determine the effectiveness of removal of perchlorate and RDX, individually and when co-mingled, using ethanol as an electron donor under steady state conditions. Three AFBRs were used to assess the effectiveness of this process in treating the wastewater. The performance of the bioreactors was monitored relative to perchlorate, RDX, and chemical oxygen demand removal effectiveness. The experimental results demonstrated that the biodegradation of perchlorate and RDX was more effective in bioreactors receiving the single contaminant than in the bioreactor where both contaminants were fed.     

Precipitator Equipment

The purpose of this section is to set forth the main elements and features of the equipment used for the collection of fly ash. Hardware and structural details of a routine nature having little or no bearing on basic performance are outside the scope of the paper.     

湿地植物齿果酸模对猪场废水净化作用研究

为了选择对养殖业废水有较强耐污及净化能力的湿地植物，提高人工湿地对养殖业废水处理效果，采用基质栽培法对耐寒植物齿果酸模在猪场废水中的生长特性及其对氮、磷的去除效果进行了研究。结果表明，该植物在氨氮浓度150mg／L左右的废水中长势良好，单株植物的生物量干重达到148．7g，其氮、磷积累量分别为4．55g和0．50g，在单株处理水量为9L，水力停留时间7d时，齿果酸模对废水中氨氮、总氮、总磷及化学需氧量的平均去除率都在70％以上。可见，齿果酸模对猪场废水有较强的耐污能力和较好的净化效果，可用于人工湿地处理养殖业废水。     

Soil calcium significantly promotes uptake of inorganic arsenic by garland chrysanthemum (ChrysanthemumL coronarium) fertilized with chicken manure bearing roxarsone and its metabolites

Roxarsone (ROX), a widely used feed organoarsenic additive, occurs as itself and its metabolites in animal manure that is commonly land used as fertilizer. Soil property impacts arsenic (As) speciation and bioavailability. Fourteen soils across China were used to conduct culture experiments to investigate As uptake by garland chrysanthemum (ChrysanthemumL coronarium), with the soils fertilized with chicken manure bearing ROX and its metabolites. The results show As(III) was the sole As form in garland chrysanthemum shoots, and As(III) and As(V) occurred in roots. Only inorganic As was detected in all soils when the plants were harvested. Stepwise regression analysis shows soil-exchangeable Ca predominated shoot As(III) concentration (shoot As(III) = 1.60030 soil Ca, R ² = 0.8832***). Therefore, ROX is transferred into the human food chain finally as inorganic As in plants. Application of animal manure bearing ROX and its metabolites is not recommended in Ca-rich soils to avoid excess inorganic As dietary exposure.