多效膜蒸馏技术浓缩回收废水中的二甲基亚砜

利用具有内部潜热回收功能的气隙式多效膜蒸馏(MEMD)组件对含二甲基亚砜(DMSO)的化纤废水进行了浓缩回收研究,考察了料液中DMSO浓度、进料流量、进料温度和膜侧进口温度对膜通量、造水比、分离因子和回收率的影响。结果表明,多效膜蒸馏可以将DMSO废水浓缩至200~300 g/L;初始浓度为6.2 g/L时,造水比和分离因子最高值分别为12.4和76.0;虽然膜通量、造水比和分离因子均随料液浓度增大而下降,但是当DMSO浓度达到200 g/L时,膜通量、造水比、分离因子仍分别高达3.74 L/(m2·h)、7.1、32.1;在整个浓缩过程中,回收率维持在99.6%以上;当DMSO废水浓缩达到150 g/L以上时,含有少量DMSO的渗透液可作为二次料液继续用MEMD过程浓缩。膜组件在连续运行的1个月内保持了良好的操作性能。该实验研究表明,多效膜蒸馏过程可以高效节能地浓缩回收化纤废水中的DMSO。     

硫酸法钛白工艺改进及其废酸治理

提出了利用钛白工艺过程中产生的20％废酸与废铁皮反应制备硫酸亚铁,试验表明,采用这一新工艺,不仅解决了长期困扰钛白生产厂家使用硫酸法生产钛白造成的废酸污染环境问题,而且保证了钛白粉质量稳定,回收率提高,同时开发出的副产品硫酸亚铁,给企业创造了显著的经济效益。     

高铁脱硫渣制备高纯度硫酸亚铁及草酸亚铁的研究

以高铁脱硫渣为原料，采取酸浸、除杂和结晶等工艺制备出99%以上硫酸亚铁晶体。研究了酸浸过程中硫酸浓度、浸取温度、时间对铁浸出率的影响，分析了各个影响因素的规律性。结果表明：适宜的浸取条件为硫酸溶液质量分数为25%，在70℃下，不断搅拌浸取6 h。固液分离后调节硫酸亚铁溶液pH=1～2，在70℃下蒸发浓缩结晶，即可得到99%以上硫酸亚铁晶体。     

高原山地城市重气泄漏扩散的示踪实验研究

为分析高原山区城市(个旧市)重气泄漏扩散规律,进行了重气泄漏扩散环境风洞实验。实验表明,重气浓度主要集中于近地层,测点的重气浓度随风速增大先增大后减小,存在一个危险风速,通过曲线拟合所得危险风速值与风洞实验所得危险风速值相近。在该风速下,重气浓度达到最大,且粘滞系数也最大,结果表明,粘滞系数越大越不利于重气的扩散。     

蒸锗废酸综合利用研究

提锗的工序之一,是用盐酸蒸馏锗精矿。为提高锗的蒸出率和分离砷,常加入氧化剂和硫酸。蒸馏时锗以 GeCl_4形态逸出,经冷凝后得液态 GeCl_4,再进一步加工成锗。蒸出锗后,留在釜中的溶液称为“蒸锗废酸”。此废酸排入澄清池,HCl 在较高的温度和浓度下,弥散入     

废硫酸和废白泥制取二水石膏

利用废硫酸和废白泥制取二水石膏的技术于1988年12月24日在杭州通过鉴定。这项技术解决了钛白废酸和废白泥变废为宝的出路,所制取的石膏可作为水泥缓凝剂。杭州硫酸厂生产钛白粉过程中产生了4％浓度的废硫酸25000吨,与相邻的华丰造纸厂碱回收中所产     

膜萃取技术回收浓缩废水中的邻甲苯胺

采用均质硅橡胶膜构建了卷绕式膜组件,以盐酸溶液为萃取液回收浓缩废水中的邻甲苯胺。通过考察进水浓度、萃取液p H、温度、离子强度、进水流速等因素对去除过程及回收率的影响,探讨了采用膜萃取技术回收浓缩邻甲苯胺的条件与机制。结果表明:膜萃取技术可以将2 g/L的邻甲苯胺废水浓缩至约10 g/L,且随着料液浓度增加,邻甲苯胺回收率先增后降,过高的邻甲苯胺浓度可能会造成膜选择性下降;萃取液p H是影响回收率的重要因素之一,1≤p H≤2时污染物回收率高于95%;无机盐离子可以促进邻甲苯胺的回收,当盐离子含量超过10%时,回收率显著提高;进水流速在2~20m L/min之间变化时,回收率先增后降,膜阻和解吸速率依次成为主要影响因素。该实验研究表明,膜萃取技术可以高效节能地的浓缩回收生产废水中的邻甲苯胺。     

酸回收的扩散渗析技术及其发展现状

介绍了扩散渗析酸回收技术的应用领域、产生过程和工作原理，着重列举了当前国内外对扩散渗析技术的研究和应用现状，展望了该技术的发展前景。该技术几乎不耗能源，是其他膜过程不可取代的，在资源日益紧张的今天，其应用前景十分乐观。     

废弃LCD面板金属铟的超声协同浸出

随着LCD报废数量的逐年增多,废弃LCD面板所含金属铟的回收再用已成为铟资源回收领域急需解决的问题。为提高废弃LCD面板金属铟的回收效率,研究提出利用超声对其进行协同浸出,以硫酸为浸出液考察超声及不同反应条件对铟浸出效率的影响。研究结果显示,超声协同能有效提高铟的浸出效率,在实验参数范围内铟的浸出率随超声功率、反应温度及酸浓度的增加而增大,随物料粒径增大而减小。在超声功率为800 W、反应温度60~70℃、硫酸浓度0.5mol/L、物料粒径小于0.5 mm条件下,浸出反应5 h铟的浸出率可达74.1%。在此基础上,研究进一步分析了超声对铟浸出反应的协同作用机制,指出热学与机械作用是超声促进废弃LCD面板金属铟浸出反应进行、提高铟浸出效率的主要作用机制。     

热镀锌厂酸洗废水及锌灰中锌回收

分别采用蒸酸法、氨络合法和硫化沉淀法分离回收热镀锌厂酸洗废水及锌灰中锌铁。分别考察了酸洗废水中盐酸的逸出特性和氨浸法回收蒸馏渣中锌的效果；利用酸洗废水的酸度浸取锌灰中的锌并用氨络合法分离酸浸出液中锌铁；利用硫化物不同溶度积选择性沉淀酸浸出液中的锌，考察了Na2S加入量、曝气时间、反应溶液pH和反应时间的影响。研究结果表明硫酸的加入能提高盐酸的蒸发率但效果不明显，氨络合法难于有效分离锌铁，但硫化物沉淀法可较好地分离锌铁，铁回收率可达97．12％，锌沉淀率达到99．99％，所得沉淀物中ZnS纯度为68．51％。     

富马酸的清洁生产工艺

富马酸的生产方法有很多种，主要有淀粉石蜡发酵和马来酸异构化。而马来酸异构化又有光异构化、生物异构化和化学品异构化。镇江市联港化学科技有限公司采用硫尿催化异构化来生产富马酸，是目前生产富马酸最主要的生产方法，并且已完全实现清洁生产。     

重金属离子在腐植酸上吸附的研究

对4种代表性重金属离子在腐植酸上吸附、pH对竞争吸附的影响及其吸附机理进行了研究。结果表明，Cu2＋、Pb2＋、Zn2＋的吸附等温线为F型，而Cd2＋等温线为L型；2．5＜pH＜3．5时，竞争吸咐次序为Cu2＋＞Pb2＋＞Cd2＋＞Zn2＋；pH＞5．0时，Cd2＋＞Cu2＋＞Zn2＋＞Pb2＋；Cu2＋在腐植酸上的吸附主要是以与腐植酸形成配合物的方式相互结合。     

Acid aerosols in the Pittsburgh Metropolitan area

This article presents data on ambient concentrations of selected acidic aerosols at four existing monitoring sites in the Pittsburgh PA metropolitan area. The data were collected by staff of the Allegheny County Health Department, Division of Air Quality during the summer and fall of 1993. The sampling protocol was focused on obtaining 24 h-average ammonia, ammonium, acidic sulfates, and particle strong acids data on a 2 to 3 day cycle. The data were obtained using Harvard University School of Public Health's “Short-HEADS” annular denuder sampling train. The Pittsburgh area is of interest because it is downwind of a major regional source of sulfur and nitrogen emissions from coal-burning power plants: the Ohio River Valley. The data presented here indicate that ground-level concentrations of acidic aerosols in Pittsburgh are highly correlated spatially and that many pollutants are higher on days when ground-level wind direction vectors indicate that wind is coming from the southwest rather than from the Pittsburgh source area itself. The monitoring site that is most upwind of the Pittsburgh source area – South Fayette – has particle strong acid levels about twice those of sites closer in to the Pittsburgh central business district.     

柠檬酸对小麦吸收铜的影响

通过土培和水培试验,研究了柠檬酸对小麦吸收铜的影响.土培结果表明：柠檬酸对土壤中的铜有一定的活化能力,使土壤中生物有效性的铜含量提高,从而提高了小麦中铜的含量,并且表明茎叶中的元素铜含量一般比根中的铜含量要低.水培结果表明：柠檬酸对小麦积累铜存在＂高抑低促＂的生物效应.     

酸雨对苏州市文物古建筑的影响初探

近年来，苏州市区酸雨出现频率增加，降水pH值下降，威胁着众多的文物古建筑。因此从苏州现存文物古建筑的五种材质入手，剖析酸雨对文物古建筑的影响，并对国家重点保护文物罗汉院双塔及正殿遗址典型的案例进行了剖析。     

2,4-Dichlorophenoxy Acetic Acid Mineralization in Amended Soil

The application of municipal biosolid or liquid hog manure to agricultural soils under laboratory conditions at 20°C influenced the fate of the herbicide 2,4-D [2,4-(dichlorophenoxy)acetic acid] in soil. When 2,4-D was added to soil at agronomic rates immediately after the addition of manure or biosolids to a coarse-textured soil, the percentage of 2,4-D mineralized at 100 days was about 47% for both treatments, compared to only 31% for control soils without amendments. The enhanced 2,4-D mineralization as a result of amendment addition was due to an increased heterotrophic microbial activity, with the greatest increases in soil respiration occurring for soils amended with biosolids. When additions of 2,4-D were delayed for one, two, or four weeks after the amendments were applied, the additions of amendments generally reduced 2,4-D mineralization in soil, particularly for manure, indicating that the effect of amendments on enhancing soil microbial activities diminished over time. In contrast, the mineralization of 2,4-D in control soils was less dependent on when 2,4-D was applied in relation to pre-incubations of soil for zero, one, two, or four weeks. The effect of manure on decreasing 2,4-D mineralization in specific soils was as large as the effect of soil texture on differences in 2,4-D mineralization across soils. Because manure was not found to impact 2,4-D sorption by soil, it is possible that 2,4-D mineralization decreased because 2,4-D transformation products were strongly sorbed onto organic carbon constituents in manure-amended soils and were therefore less accessible to microorganisms. Alternatively, microorganisms were less likely to metabolize the herbicide because they preferentially consumed the type of organic carbon in manure that is a weak sorbent for 2,4-D.     

模拟酸雨对土壤中的铜释放与缓冲作用研究

研究了模拟酸雨淋溶过程中对南方主要土壤重金属Cu的缓冲及释放现象。结果表明，土壤的Cu释放量随淋溶模拟酸雨pH值的下降而增大，酸雨的pH值是影响土壤重金属离子释放和迁移的主要因素，当pH〈3．0时，Cu的释放量明显增加，并且增长迅速。此外，淋溶量也是影响土壤中Cu释放的重要因素。     

酸雨对建筑材料的影响及防治研究综述

综合分析了酸雨对建筑外墙的涂料、石材、混凝土等主要建筑构件的腐蚀原理，并提出了防治措施，来预防酸雨对建筑材料的侵害。     

Base-cation deposition in Europe—part II. Acid neutralization capacity and contribution to forest nutrition

An assessment was made of the capacity of base cations to neutralize acid deposition and of the contribution of base cation deposition to forest nutrition in Europe. In large parts of southern Europe more than 50% of the potential acid deposition was found counteracted by deposition of non-sea salt Mg²⁺ + Ca²⁺ + K⁺. In central and northwestern Europe, base cation deposition usually amounted to less than 25% of the acid input. Smallest base cation deposition relative to potential acid deposition was found in southern Scandinavia, Denmark, northern Germany and The Netherlands. A similar spatial pattern was found for the neutralization of acid anions in precipitation. Whereas in Scandinavia weathering is the dominant supplier of base cation to forest soils, in eastern and southern Europe, forests mainly rely on atmospheric deposition for the supply of base cations. Using error propagation, the random and systematic error in acid neutralization capacity for an average grid cell of 10 × 20 km was estimated to equal 45–55% and 50–55%, respectively.