Fenton 试剂液相氧化法净化含H2S 的气体

利用Fenton 试剂液相氧化法净化含H2S 的气体,研究了初始pH 值、温度、H₂S 浓度、H₂O₂ 浓度、气体流量、[H₂O₂]/[ Fe²⁺]比值、金属离子等因素对H₂S 去除率的影响.结果表明,当pH<2.52 时,pH 值升高,去除率逐渐提高;当pH>2.52 时,去除率下降;pH=2.52 时,去除效率最高.去除率随H₂O₂ 浓度增加而提高;H₂O₂ 浓度一定时,去除率随[H₂O₂]/[Fe²⁺]比值的增加而升高;[H₂O₂]/[Fe²⁺]接近于1 时达到最大.温度提高,去除率提高.实验条件下,去除率随气体流量的增加而下降.入口H2S 浓度越低去除率越高.Fe3+对Fenton 反应有促进作用,添加金属离子的Fenton 试剂氧化H2S 能力顺序为Fe²⁺+Fe³⁺>Fe²⁺>Fe³⁺.     

两级滴滤去除硫化氢和甲硫醇混合恶臭气体

把氧化硫硫杆菌(T. thiooxidans)、排硫硫杆菌(T. thioparus)组成的自养菌群和黄单胞菌(Xanthomonas)为主的异养菌群分别接种在两个生物滴滤反应器中,将其依次串联净化处理硫化氢(H₂S)、甲硫醇(MT)混合臭气.一级反应器(A^#)的复合自养菌在酸性环境下对负荷为7～8g/(m³h)的H₂S平均去除率可达94%,且不受混合气体中MT含量的影响.二级反应器(B^#)适于中性环境,对负荷为4～5g/(m^{3h)的MT平均去除率为83%.若H₂S在混合气体中浓度过高,经A#处理后的浓度仍高于50mg/m3,可导致后反应器酸化,使MT脱臭效率显著下降.}     

冶金粉尘硫容量的实验研究

在25-650温度范围内测定了由Fe 、Ca、 Zn 、Mn等氧化物组成的高炉冶金粉尘脱除H₂S的硫容量,结果表明,反应温度驵成对高炉冶金粉尘硫容量有较大影响,在25-650范围内,硫容量增加：当温度低于350时,CA,Zn,Mn氧化物对冶金粉尘硫容量起主要作用 ,且碳的存在于提高治金粉尘对H₂2S的吸附能力,可适度提高冶金粉尘硫容量;温度大于350时,氧化物对冶金粉尘硫容是起主要作用,碳含量对冶金粉尘硫容量的影响较小,高炉 冶金粉尘脱流主要受Fe氧化物脱硫反应及H₂2S氧化物脱硫反应及H₂2S在冶金粉中的扩散影响.     

烟气中水、氧含量对羟基资源化脱硫效率的影响

采用强电场电离放电方法,将烟气中H₂O、O₂通过电离、分解和超激发,形成羟基和水合电子等自由基.在无吸收剂、催化剂条件下,自由基直接氧化SO₂生成H₂SO₄微滴,再用电收雾器加以回收.结果表明,烟气中H₂O含量对硫脱除率的影响率比O₂的影响率高出1倍,H₂O、O₂含量对SO₂脱除率影响比值与理论计算值的偏离度为4.3%.烟气中H₂O、O₂的含量可满足强电离放电羟基自由基脱硫过程的需要.     

磷钼杂多化合物脱硫体系脱硫特性与再生规律

以液相氧化脱硫工艺开发为目的,采用尾气H₂S浓度动态监测法研究了磷钼杂多化合物脱硫体系的脱硫特性;采用氧化还原电位监测法研究了该体系的再生规律结果表明,磷钼酸钠（NaHPA）体系的脱硫性能随温度升高而有所降低,随进气H₂S浓度的提高而相应降低,随吸收剂浓度的提高而显著增强．几种主要因素对磷钼酸钠脱硫体系再生过程的影响规律为吸收剂浓度提高再生时间缩短;温度升高再生时间缩短温度超过 50℃冉生时间缩短幅度趋缓;增大空气流最冉生时间缩短,空气流量超过1.650Lmmin冉生时间趋于恒定：进气 H₂S浓度提高冉生时间延长．NaHPA复配体系的再生性能较单一的NaHPA为优,偏钒酸钠对体系的再生有催化作用     

广州市大气中过氧化物的研究

采用高效液相色谱(HPLC)荧光法于1998年7月和10月测定了广州市大气中的5种过氧化 物:过氧化氢(H₂O₂)、羟甲基过氧化氢(HMHP)、甲基过氧化氢(MHP)、1-羟乙基过氧化氢(1-H EHP)及乙基过氧化氢(EHP).其中主要过氧化物是H₂O₂、HMHP和MHP,其最高浓度分别为1.6(10 ^-9、0.67(10^-9和0.54(10^-9(V/V).在光照强,相对湿度低的情况下,H₂O₂和MHP呈现明显的日 变化规律,早晚浓度低,最大值多出现在14:00～16:00.同时测定了大气温度,湿度和紫外辐射U VB及大气中O₃, NO_X和SO₂,发现H₂O₂和MHP与O₃、温度和UVB具有一定的正相关关系,而与NO_X, SO₂ 和相对湿度具有一定的负相关关系.     

内电解-Fenton 氧化-膜生物反应器处理腈纶废水

采用内电解-Fenton 氧化-序批式膜生物反应器组合工艺处理腈纶废水.结果表明,在进水Ph 值为3、内电解反应时间2h、H₂O₂ 浓度1500 mg/L、Fe²⁺浓度600mg/L、Fenton 反应时间2h 的条件下,内电解-Fenton 组合工艺对COD 的去除率为72%,进水COD 从1328mg/L下降到369mg/L,废水BOD₅/COD 从0.14 上升到0.33,CN-从8.6mg/L 下降到0.215mg/L,提高了废水可生化性,为后续的生物处理创造了良好的条件.出水采用序批式膜生物反应器处理,在停留时间20h、缺氧搅拌90min、好氧120min 条件下,COD 去除率为80%,NH₄₊-N 去除率95%,BOD₅ 去除率92.6%,CN-去除率90.7%.最终出水COD、BOD5、NH4+-N、CN-、SS 分别为61,9.3,2.55,0.02,13mg/L     

VUV/TiO2/H2O2法去除水中微量硝基苯

研究了过氧化氢(H₂O₂)强化的真空紫外光催化(VUV/TiO₂/H₂O₂)方法对水中微量硝基苯(NB)的去除效果,同时考察了H₂O₂ 投加量、NB 初始浓度、重碳酸盐和腐殖酸对NB 降解的影响.采用负载在钛片上的二氧化钛(TiO₂)薄膜为光催化剂,以能发射185nm 真空紫外线(VUV)的紫外灯为光源.结果表明,去离子水中50µg/L 的NB 反应60s 后去除率即达到97.9%.随H₂O₂ 投加量的增加, VUV/TiO2/H₂O₂ 对NB的降解速率先增后减;初始浓度低于170µg/L 时,初始浓度对NB 降解影响不大;重碳酸盐和腐殖酸对硝基苯降解有显著的抑制作用.VUV/TiO₂/H₂O₂能快速有效地去除地表水(含碳酸盐和天然有机物)中的微量NB,5min 内初始浓度为90µg/L的NB去除率达到94.1%, UV₂₅₄在4min 内也降低了53.3%.     

硫酸盐还原菌颗粒污泥形成条件研究

在生物反应器中培养出高活性的生物相是使其稳定、高效运行的关键．在上流式厌氧污泥床反应器中,对硫酸盐还原菌颗粒污泥形成过程及形成条件进行了研究,结果表明,在中温（35 ±1 ℃） 条件下,当进水SO^2-₄ 小于1600mg/L、COD/SO^2-₄大于3 时,控制反应器污泥负荷大于0.3kgsO^2-₄/kg Vss·d 、水力负荷为0.2m³/m²·h 有利于颗粒污泥的形成和生长．     

固定化微生物处理含氨臭气的研究

采用海藻酸钙包埋固定化生物颗粒,利用固定床反应器处理含氨臭气的研究结果表明,系统的脱臭、硝化效果较好;其气相NH₃去除率在92％以上,固定化生物颗粒的硝化速度大于0.63gN/kg固定化湿颗粒·d,远高于土壤及生物膜NH₃气脱臭法。对进气NH₃－N负荷、pH值、水份喷淋密度与硝化、脱臭效果的关系研究结果表明,系统获得高效脱臭、硝化效果的最佳进气负荷为3.99gN/kg固定化湿颗粒·d,pH值为7.0～8.0,淋洗密度为0.61m³/m²塔截面·d。     

Evaluation of phytoextracting cadmium and lead by sunflower, ricinus, alfalfa and mustard in hydroponic culture

Soil contaminated with heavy metals cadmium(Cd)and lead(Pb)is hard to be remediated.Phytoremediation may be a feasible method to remove toxic metals from soil,but there are few suitable plants which can hyperaccumulate metals.In this study,Cd and Pb accumulation by four plants including sunflower(Helianthus annuus L.),mustard(Brassica juncea L.),alfalfa(Medicago sativa L.), ricinus(Ricinus communis L.)in hydroponic cultures was compared.Results showed that these plants could phytocxtract heavy metals, the ability of accumulation differed with species,concentrations and categories of heavy metals.Values of BCF(bioconcentration factor)and TF(translocation factor)indicated that four species had dissimilar abilities of phytoextraction and transportation of heavy metals.Changes on the biomass of plants,pH and Eh at different treatments revealed that these four plants had distinct responses to Cd and Pb in cultures.Measurements should be taken to improve the phytoremediation of sites contaminated with heavy metals,such as pH and Eh regulations,and so forth.     

Oxidation of As(Ⅲ) by potassium permanganate

The oxidation of As(Ⅲ) with potassium permanganate was studied under conditions including pH, initial As(Ⅲ) concentration and dosage of Mn(Ⅶ). The results have shown that potassium permanganate was an effective agent for oxidizing of As(Ⅲ) in a wide pH range. The pH value of tested water was not a significant factor affecting the oxidation of As(Ⅲ) by Mn(Ⅶ). Although theoretical redox analyses suggest that Mn(Ⅶ) should have better performance in oxidization of As(Ⅲ) within lower pH ranges, the experimental results show that the oxidation efficiencies of As(Ⅲ) under basic and acidic conditions were similar, which may be due to the adsorption of As(Ⅲ) on the Mn(OH)2 and MnO2 resulting from the oxidation of As(Ⅲ).     

Distribution and ecological effect of mercury in Laogang landfill, Shanghai, China

Laogang landfill near Shanghai is the largest landfill in China, and receives about 10000 t of daily garbage per day, Samples of topsoil and plants were analyzed to evaluate mercury pollution from the landfill. For topsoil samples, there were significant correlations among total mercury （HgT）, combinative mercury （Hgc） and gaseous mercury （HgG）, and content of total organic carbon （TOC）, but, no significantly relationship was found between Hg content and filling time. Hg content changes in vertical profiles with time showed that the average Hgv of profiles 1992, 1996, and 2000 was similar, but their average HgG was quite different. HgT was significantly correlated with Hgc in profile 1992 and 2000, and Hgv was significantly correlated with Hg6 in profile 1996. HgG/Hgv ratio in profile samples decreased in the order of （HgG,/HgT）1992〉（HgG/HgT）1996〉〉（HgG/HgT）2000. A simple outline of Hg release in landfill could be drawn： with increasing of filling time, degradation undergoes different biodegradation, accordingly, gaseous mercury goes through small, more, and small proportion to total mercury. Distribution of Hg in plants was inhomogeneous, following the order of leaf〉root〉stem. The highest value of leaf may be associated with higher atmospheric Hg from landfill. Ligneous plants （e.g. Phyllostachys glanca, Prunus salicina and Ligustrum lucidum） are capable of enriching more Hg than herbaceous plants.     

EDTA-enhanced phytoremediation of lead contaminated soil by Bidens maximowicziana

Phytoremediation is a potential cleanup technology for the removal of heavy metals from contaminated soils.Bidens maximowicziana is a new Pb hyperaccumulator,which not only has remarkable tolerance to Pb but also extraordinary accumulation capacity for Pb.The maximum Pb concentration was 1509.3 mg/kg in roots and 2164.7 mg/kg in overground tissues.The Pb distribution order in the B. maximowicziana was:leaf>stem>root.The effect of amendments on phytoremediation was also studied.The mobility of soil Pb and the Pb concentrations in plants were both increased by EDTA application.Compared with CK(control check),EDTA application promoted translocation of Pb to overground parts of the plant.The Pb concentrations in overground parts of plants was increased from 24.23-680.56 mg/kg to 29.07-1905.57 mg/kg.This research demonstrated that B.maximowicziana appeared to be suitable for phytoremediation of Pb contaminated soil,especially,combination with EDTA.     

Decomposition of alachlor by ozonation and its mechanism

Decomposition and corresponding mechanism of alachlor, an endocrine disruptor in water by ozonation were investigated. Results showed that alachlor could not be completely mineralized by ozone alone. Many intermediates and final products were formed during the process, including aromatic compounds, aliphatic carboxylic acids, and inorganic ions. In evoluting these products, some of them with weak polarity were qualitatively identified by GC-MS. The information of inorganic ions suggested that the dechlorination was the first and the fastest step in the ozonation of alachlor.     

Enzymatic oxidation of aqueous pentachlorophenol

The influence of the nonionic surfactant Tween 80 on pentachlorophenol （PCP） oxidation catalyzed by horseradish peroxidase was studied. The surfactant was tested at concentrations below and above its critical micelle concentration （CMC）. Enhancement of PCP removal was observed at sub-CMCs. The presence of Tween 80 in the reaction mixture reduced enzyme inactivation which occurred through a combination of free radical attack and sorption by precipitated products. A simple first-order model was able to simulate time profiles for enzyme inactivation in the presence or absence of Tween 80. At supra-CMCs, the surfactant caused noticeable reductions in PCP removal, presumably through micelle partitioning of PCP which precluded the hydrophobic PCP molecule from interacting with the enzyme.     

Chlorobenzenes in waterweeds from the Xijiang River （Guangdong section） of the Pearl River

The Xijiang River is the major source of water for about 4.5 millions of urban population and 28.7 millions of rural population. The water quality is very important for the health of the rural population. The concentration and distribution of chlorobenzenes (CBs) in both water and waterweeds collected from 4 stations in the Xijiang River (Gangdong section) of the Pearl River in April and November were determined. The result showed that nearly every congener of CBs was detected. The total contents of CBs (∑CBs) in the river water ranged from 111.1 to 360.0 ng/L in April and from 151.9 to 481.7 ng/L in November, respectively. The pollution level of CBs in the water in April was higher than that in November. The contents of ∑ CBs in waterweeds ranged from 13.53×102 μg/g to 38.27×102μg/g dry weight (dw). There was no significant difference between April and November in waterweeds. The distribution of CBs in roots, caulis, and leaves of Vallisneria spiralis L. showed different patterns. The leaves mainly contained low-molecular-weight CBs(DCBs), whereas the roots accumulated more PCBs and HCBs. The average lgBCFlip (bioconcentration factor) of CBs ranged from 0.64 to 3.57 in the waterweeds. The spatial distribution character of CBs in the Xijiang River was: Fengkai County ＜ Yunan County ＜Yun'an County ＜ Gaoyao County according to the ∑CBs, and the pollution deteriorated from the upstream to the downstream of the Xijiang River. Further analysis demonstrated that the discharge of waste containing CBs may be the main source of CBs pollution in the Xijiang River.     

基于综合水质标识指数和对应分析法的校园河道水质评价

以三峡大学的校园河道求索溪为研究对象,利用综合水质标识指数法确定求索溪水质类别,分析其水质时空变化规律,并利用对应分析法得出求索溪中不同监测点的主要污染因子.研究结果表明:求索溪整体的综合水质标识指数为7.423,整体水质为劣V类(地表水环境质量标准GB 3838-2002)且黑臭.从时间变化来看,求索溪4月份的水质最差,5月份次之,4、5月份所有监测点的水质都劣于V类且黑臭;8月份水质最好,水质为Ⅳ类;从空间分布来看,8个监测点综合水质标识指数均超过6.0,水质为劣V类,其中6号监测点的水质相对最好,监测点3号的水质相对最差;对应分析法得出求索溪的整体水体污染程度受总氮因子的影响最大,其次为总磷.该研究拟为求索溪及类似校园河道的水环境治理研究提供基础依据和参考.     

Degradation of 2,4-dichlorophenol with a novel TiO2/Ti-Fe-graphite felt photoelectrocatalytic oxidation process

Degradation of 2,4-dichlorophenol(2,4-DCP)was studied in a novel three-electrode photoelectrocatalytic(PEC)integrative oxidation process,and the factors influencing the degradation rate,such as applied current,flow speed of O_2,pH,adscititious voltage and initial 2,4-DCP concentration were investigated and optimized.H_2O_2 was produced nearby cathode and Fe~(2 )continuously generated from Fe anode in solution when current and O_2 were applied,so,main reactions,H_2O_2-assisted TiO_2 PEC oxidation and E-Fenton reaction,occurred during degradation of 2,4-DCP in this integrative system.The degradation ratio of 2,4-DCP was 93% in this integrative oxidation process,while it was only 31% in E-Fenton process and 46% in H_2O_2-assisted TiO_2 PEC process.So,it revealed that the degradation of 2,4-DCP was improved greatly by photoelectrical cooperation effect.By the investigation of pH,it showed that this integrative process could work well in a wide pH range from pH 3 to pH 9.     

Effect of copper on the degradation of pesticides cypermethrin and cyhalothrin

The influence of coexisting copper (Cu) ion on the degradation of pesticides pyrethroid cypermethrin and cyhalothrin in soil and photodegradation in water system were studied.Serial concentrations of the pesticides with the addition of copper ion were spiked in the soil and incubated for a regular period of time,the analysis of the extracts from the soil was carried out using gas chromatography (GC).The photodegradation of pyrethroids in water system was conducted under UV irradiation.The effect of Cu~(2 ) on the pesticides degradation was measured with half life (t_(0.5)) of degradation.It was found that a negative correlation between the degradation of the pyrethroid pesticides in soil and Cu addition was observed.But Cu~(2 ) could accelerate photodegradation of the pyrethroids in water.The t_(0.5) for cyhalothrin extended from 6.7 to 6.8 d while for cypermethrin extended from 8.1 to 10.9 d with the presence of copper ion in soil.As for photodegradation,t_(0.5) for cyhalothrin reduced from 173.3 to 115.5 rain and for cypermethrin from 115.5 to 99.0 min.The results suggested that copper influenced the degradation of the pesticides in soil by affecting the activity of microorganisms.However, it had catalyst tendency for photodegradation in water system.The difference for the degradation efficiency of pyrethroid isomers in soil was also observed.Copper could obviously accelerate the degradation of some special isomers.