硅藻土-无定形碳-氧化铁三元复合体系降解三硝基甲苯的研究

煤系共伴生非金属矿产开发及综合利用难度大。本文针对先锋褐煤共伴生硅藻土高有机质、高铁的特点,提出硅藻土原矿经提纯处理后,在N2作为保护气氛下,高温煅烧形成硅藻土-无定形碳-氧化铁三元复合材料,在类Fenton体系下,去除TNT污染物的开发利用技术路线。本文考察了硅藻土处理条件、反应时间、H2O2浓度、三元复合硅藻土投加量、pH值等因素对TNT降解效能的影响。研究表明三元复合硅藻土对TNT吸附降解的最佳工艺条件为:硅藻土用量为2 g/L,H2O2(30%)4 m L/L,pH值1,反应时间2.5 h。该工艺条件下,50 mg/L TNT去除率为98%。     

酪氨酸酶固定化碳材料对苯酚的生物降解性能

以新型碳材料氧化石墨烯作为载体,利用共价结合方法制备酪氨酸酶固定化氧化石墨烯复合物,并利用该复合物对苯酚进行催化降解,探讨酶的加载特性和酶的催化活性,以及固定化酪氨酸酶催化降解苯酚的最优条件及储存稳定性。通过对固定化酪氨酸酶进行活性和固定量分析后认为:单位质量载体的酶固定量为1.78 mg/mg,单位质量载体的酶活性为1 880.6 U/mg;固定化酪氨酸酶在30h内对47.06mg/L苯酚的降解率可达86.3%,降解反应的最优条件为pH=7.0、温度=25℃;固定化酪氨酸酶在4℃条件下30d后仍保持初始活性的77.7%,其稳定性优于游离酪氨酸酶。另外,在氧化石墨烯上引入磁颗粒,既简化了酶固定流程,又能做到回收利用。     

固定化酶在高浓度有机废水处理中的应用

选用硅胶、活性炭、大孔树脂三种载体,在一定条件下用物理吸附法固定蛋白酶,三种载体固定的蛋白酶对含高浓度蛋白质的淀粉黄浆废水进行水解实验,确定水解最佳的pH值范围,并在此条件下研究三种不同载体上固定化酶的活性及其水解规律。结果表明：大孔树脂对蛋白酶的固定效果良好,并对含高浓度蛋白质的废水处理效果最好,其最佳反应pH值为5.5,反应进行0.5 h时酶的催化效果最好,氨基酸产生速度达到30.82 mg/min,且在3h后该速度仅减少3.74 mg/min;6 h时对蛋白质的去除率达到39.93%。     

紫外光及日光下天然金红石光催化降解苯酚的研究

研究了山西代县天然金红石在紫外光和日光照射条件下对苯酚的光催化降解性能,考察了光照时间、pH值、苯酚初始浓度以及H2O2添加量对降解过程的影响。在紫外光照射下,酸性条件(pH=3.5)利于光催化降解,中性和碱性条件下降解效率较低;当初始浓度为60mg/L时,降解速率可达1.922mg/(L.h);H2O2作为电子捕获剂可提高苯酚降解速率,最佳投加量为2mL/L。在日光条件下,天然金红石对苯酚表现出良好的降解性能,照射7h后,降解率达87.68%,仅略低于P25型TiO2(99.72%),可在14h内完全降解。根据电子探针和X射线衍射分析结果,认为天然金红石晶格中的V、Fe等杂质可能是提高其可见光响应效果和光催化活性的主要原因。     

超声波-芬顿法协同降解亚甲基蓝的研究

以亚甲基蓝溶液为模型污染物,在超声波芬顿法协同作用下对亚甲基蓝染料废水的降解作用进行了研究,考察了反应时间、H2O2用量、溶液pH值、Fe^2＋的浓度等因素对亚甲基蓝溶液降解的影响。结果表明,超声波单独降解亚甲基蓝溶液脱色效果不明显,超声波协同H2O2降解亚甲基蓝,加入30%H2O26mL,脱色率约45.80%;溶液pH2.80,Fe^2＋浓度为30mmol/L时,超声波芬顿法协同降解甲基蓝180min,脱色率达92.70%。试验证明,超声波芬顿法是一种降解亚甲基蓝的有效方法。     

Degradation of phenol of high concentration by FeAIOx/MMT catalyzed Fenton reaction

以蒙脱土为载体制备负载型Fe/Al复合氧化物（FeAlOx/MMT）用于催化Fenton反应降解高浓度苯酚废水。实验结果表明,活性相FeAlOx中Fe/Al摩尔比为0.22时制备所得催化剂对Fenton反应具有最佳活性,且Fe/Al复合氧化物并未嵌入蒙脱土层间。在低温和高pH条件下催化体系存在诱导期,诱导期内FeAlOx/MMT缓释出Fe离子并进而由Fe离子催化溶液中的Fenton反应。通过对非均相催化降解苯酚废水的动力学研究发现,H2O2初始浓度、溶液的pH和反应温度对COD降解效率具有显著影响。调节降解过程中的温度序列和氧化剂引入程序能够缓解高温和高双氧水浓度双重因素耦合导致的HO.自消耗。在优化的降解条件下使用理论用量的H2O2可使得1 g/L的苯酚废水中苯酚降解率达到100%,而COD的降解率则达到97%。     

锰钾矿处理高浓度含酚废水研究

对人工合成锰钾矿氧化降解高浓度含酚废水的特性进行了研究。结果表明,体系酸度和矿物用量是影响废水处理效果的重要因素。加酸量为0.12 mol/L,矿物用量20 g/L,温度70℃,反应时间3 h时效果最佳,废水总酚含量由1269 mg/L降低至268 mg/L,同时CODCr与TOC去除率为31.2%和70.5%。经GC/MS测定,水中酚类物质为苯酚、甲基苯酚、二甲基苯酚,最佳条件下,酚类物质浓度已低至检测限以下,水中残余吲哚、长链烷烃、喹啉及其衍生物等难降解有机物。     

N2气氛下煅烧的黄铁矿对As(Ⅲ)的吸附作用

微量As(Ⅲ)是水中较难去除的毒性物质,天然黄铁矿对水中As(Ⅲ)的去除能力低于磁黄铁矿.将黄铁矿在氮气下高温煅烧使其转变为由磁黄铁矿构成的多孔结构化材料,具有较高的比表面积和表面化学反应活性,在地下水As(Ⅲ)去除方面具有潜在的应用前景.考察了煅烧温度、煅烧时间、pH值以及溶解氧对去除水中As(Ⅲ)的影响.结果表明黄铁矿煅烧生成的单斜磁黄铁矿对As(Ⅲ)具有最佳去除效果,最佳煅烧条件为600℃煅烧1 h;在水溶液有溶解氧条件下煅烧黄铁矿去除As(Ⅲ)的适宜p H值范围较宽(4~10),而在水溶液缺少溶解氧条件下适宜pH值则变为7~10;煅烧黄铁矿在有氧水溶液中对As(Ⅲ)的吸附比缺氧水溶液中的吸附效果好.     

臭氧-超声联用处理聚乙烯醇废水

本研究采用臭氧-超声（O₃/US）联用技术处理聚乙烯醇（PVA）废水,分别考察了PVA初始质量浓度、初始pH、臭氧通入速率、超声功率、超声频率及反应时间对PVA和COD去除效率的影响,并在此基础上通过正交实验确定了降解PVA和COD的最佳实验条件。研究结果表明,超声频率对去除率有显著影响,PVA初始质量浓度对去除效率的影响较大,反应时间、超声功率、臭氧通入速率和初始pH的影响相对较小。通过影响实验和正交实验确定的最佳降解条件为:PVA初始质量浓度100 mg/L、初始pH=9、臭氧通入速率4 g/h、超声功率320 W、超声频率40 kHz、反应时间20 min,此时COD和PVA的去除效率分别为86.4%和99.3%。超声对臭氧降解聚乙烯醇废水具有明显的协同作用,在最佳条件下,臭氧-超声联用技术比单独臭氧技术对PVA的去除率增加了5.1%,对COD去除率增加了19.4%。     

天然黑钨矿可见光催化活性的实验研究

天然半导体矿物具有优良的日光催化特性。本研究选取天然钨酸盐作为研究对象,对武鸣、栗木、崇义3个不同矿区的天然黑钨矿进行了矿物学及光催化实验探究。利用X射线衍射、拉曼光谱、红外光谱、电子探针微区分析对天然样品的结构与成分进行分析,鉴定其主要矿物相为黑钨矿(Fe,Mn)[WO4],从武鸣、栗木到崇义矿区,Fe/Mn摩尔分数比从7.1、0.9到0.3依次降低。利用紫外可见漫反射测得武鸣、栗木、崇义地区样品禁带宽度分别为1.5、1.6和1.7eV,说明其具有良好的可见光响应。在pH为7的条件下用质量浓度为1g/L的样品对5mg/L的有机染料亚甲基蓝(MB)进行光催化实验(含0.01mol/L H2O2 ),结果表明武鸣地区黑钨矿实验组降解MB的效果最佳,3h后其效率分别是栗木、崇义地区样品的1.1倍和1.6倍。电子顺磁共振谱检测结果显示,反应过程中均产生氧化性羟自由基(·OH),其中效果最好的武鸣黑钨矿产生的·OH信号更强;不同自由基捕获实验证明·OH在光催化反应过程中起主要作用。进一步选取武鸣黑钨矿开展光催化降解机制研究,实验结果显示:光照下黑钨矿与H2O2共存的实验组对MB的脱色降解率可达99%(3h),只有黑钨矿的对照组降解7%的MB,只有H2O2 的对照组降解31%的MB;黑暗条件下,同时添加黑钨矿与H2O2的对照组对MB的去除率为34%。不同H2O2 浓度条件下黑钨矿降解MB符合准一级动力学方程,说明降解过程与催化剂含量无关,H2O2 更多的是充当电子受体。分析认为,不同产地黑钨矿日光催化效率与矿物铁含量呈正相关,与禁带宽度呈负相关,推测其反应机理是光催化与芬顿反应协同产生的·OH将MB氧化降解。本研究为开发利用天然矿物治理环境污染提出了新方法。     

脉冲电解处理石油废水的实验研究

石油废水中含有多种有机物,成分复杂,其治理是当今急需解决的问题.用自制的反应器以石墨为电极材料,应用脉冲电解方法,进行处理石油废水的实验.实验结果表明:在电解时间 30 min,电解电压 10 V,脉冲电源频率 3 750 Hz,占空比 50 %,pH＝9,电极间距 2.5 cm,电极直径 1.0 cm,电解质浓度 0.2 % 的条件下进行电解,废水的处理效果可达到 89 % 以上.处理后的废水低于国家第二类污染物最高允许排放浓度的二级排放标准.脉冲电解法不但处理含油废水效果显著,而且设备简单,易于操作,为处理石油废水提供了一项新技术.     

含氮污水灌溉实验研究及污染风险分析

在野外实验基地进行的含氮污水灌溉实验工作基础上,分析了污灌过程中氮化合物在土壤及地下水中迁移转化规律.研究结果表明,污灌对下层土壤及地下水中NH₄+浓度影响较小,但对NO₃-浓度影响较大,尤其是长期进行污灌的土壤,易造成地下水中NO₃-污染.利用本文推导的数学模型,可以定量预测污水灌溉后土壤水及地下水中NH₄+、NO₃-浓度的时空变化.采用Monte-Carlo法,进行含氮污水灌溉污染风险分析,结果表明,进入地下水的NO₃--N最大浓度超过污灌水NO₃--N浓度0.76倍的可能性为25%、超过污灌水NO₃--N浓度0.43倍的可能性为75%,污灌造成的地下水NO₃-污染风险必须引起注意.     

利用坡缕石酸活化废液制备聚合氯化铝铁

坡缕石粘土生产活性白土的过程中产生的酸化废液会对环境造成严重污染,利用此废液,通过加入浓碱在一定条件下聚合制备了聚合氯化铝铁,最佳聚合pH值为4.0,所得产品基本符合GB15892-2003水处理剂国家标准.混凝实验结果显示,在480 mg/L的投药量下聚合氯化铝铁对自配水的浊度去除率最高可达98.3%,且适应的pH值范围较宽,处理效果优于其他常用絮凝剂.     

Applications on agricultural and forest waste adsorbents for the removal of lead (II) from contaminated waters

At present, there is growing interest in using low cost, commercially available materials for the adsorption of heavy metals. The major advantages of adsorption technologies are its effectiveness in reducing the concentration of heavy metal ions to very low levels and the use of inexpensive adsorbent materials. In this review, agricultural and forest waste adsorbents were used to remove Pb²⁺ ions in wastewater treatment, and their technical feasibilities were reviewed in studies mainly from 2000 to 2010. They all were compared with each other by metal binding capacities, metal removal performances, sorbent dose, optimum pH, temperature, initial concentration and contact time. Although commercial activated carbon is widely used in wastewater treatment applications, it has high costs. The use of agricultural by-products as adsorbent material to purify heavy metal contaminated water has become increasingly popular through the past decade because they are less expensive, biodegradable, abundant and efficient. Instead of activated carbon, this study was focused on the inexpensive materials such as agricultural and forest waste. It was shown that these alternative adsorbents had sufficient binding capacity to remove Pb²⁺ ions from wastewater.     

Examination and Refinement of the Determination of Aqueous Hydrogen Sulfide by the Methylene Blue Method

The accurate and precise measurement of total sulfide has been of major interest for well over a century. The most commonly used method involves the formation of a methylene blue?Csulfide complex and spectrophotometric measurement of its concentration. The study presented herein compares the two most commonly used methods as outlined in Standard Methods for the Examination of Water and Wastewater (in APHA, Standard methods for the examination of water and wastewater, Washington, 1960) and by Cline (Limnol Oceanogr 14:454?C458, 1969). In addition, this study clarifies the existing confusion of Cline??s reagent preparation procedure, as it is apparent that various interpretations exist among research groups regarding reagent preparation. After evaluating both methods with respect to precision and accuracy, detection limit, sample storage time, and ease of use, the method outlined in Cline was determined to be superior. Furthermore, we suggest that the reagent concentration has to be optimized depending on the range of sulfide concentrations to increase the accuracy and precision of the method.     

Emission patterns of acrylonitrile and styrene around an industrial wastewater treatment plant in Iran

The uncontrolled releases of volatile organic compounds (VOCs) from wastewater treatment plants (WWTPs) have been highly concerned due to the associated public health risks. In petrochemical industries, WWTPs are responsible for various organic compound emissions into the atmosphere, which can considered as the main source of VOCs emission in such industries. The typical high-strength petrochemical wastewater is generated from an acrylonitrile–butadiene–styrene (ABS) resin manufacturing plant that usually needs pretreatment before discharging to the main WWTP. The objective of this study was to investigate the emissions and fates of acrylonitrile (ACN) and styrene (STM) through wastewater pretreatment units operated in an ABS manufacturing plant. In this study, the emission rates of ACN and STM were estimated by means of EPA’s Water9 emission model. Subsequently, the emission rates were used as the input data of AERMOD model to simulate the atmospheric behaviors of emitted ACN and STM. The results of Water9 model showed that 57 and 81 % of influent ACN and STM are emitted to the air through pretreatment units, respectively. For both of them, the equalization basin had the major portion of emission to the atmosphere. The concentration distribution profiles of ACN and STM resulted from AERMOD model indicted that the concentration of STM was lower than EPA reference concentration (RfC); however, the higher concentration of ACN (higher than RfC) occurred near the WWTP as well as the neighbor ambient.     

钨矿选矿废水处理新技术

采用混凝沉淀技术处理钨矿选矿废水,通过试验确定HNJY新型高效复合絮凝剂作为混凝剂最为合适,投加量为120mg/L,经处理后废水出水水质符合国家污水排放标准并能回用,废水SS约11500mg/L,处理后的出水要求为SS<10mg/L。技术经济分析,投资总费用为67.5万元,处理成本为0.60元/m3,设计工艺可靠且经济合理。本工程既防止了废水对环境的潜在污染,又解决了枯水期选矿用水不足的问题。     

Environmental risk assessment of platinum cytotoxic drugs: a focus on toxicity characterization of hospital effluents

Platinum-based cytotoxic drugs are complexes of Pt used in 50–70% of cancer patients. This study was performed during 2015, in two oncology wards of Qom hospitals in Iran. Sampling was carried out using effluent of the oncology wards for measurement of total Pt concentration. Analysis was performed by ICP–OES, and limit of detection was determined (LODs = 1 µg/L). During the sampling days, the total Pt concentration in the wastewater effluent oncology ward ranged from 5 to 762 µg/L at Shahid Beheshti Hospital and from 3 to 629 µg/L at Hazrat Masoumeh Hospital. According to the results from concentration of cytotoxic drugs, the predicted environmental concentrations (PECs) (ng/L) in wastewater treatment plant effluent and river for cisplatin, carboplatin and oxaliplatin were determined. Calculated RQ_hww showed that \(\sum {\text{RQ}}_{\text{hww}} = 1.19\). Thus, the total platinum compound drug could have potential toxicity effect on aquatic organisms. It was concluded that monitoring of cytotoxic drugs residue in hospital effluent must be considered because of their toxicity and impact on aquatic pollution. The results also revealed that PEC < 10 ng/L for all the platinum compound drugs and sum of the PEC calculation (\(\sum {\text{PEC}}_{{{\text{cis}},{\text{carbo}},{\text{oxali}}}}\)).     

利用13X沸石分子筛净化含Pb~(2+)废水的实验研究

采用静态间歇法 ,实验研究了含Pb2 +废水的 pH值及吸附时间对 13X沸石分子筛吸附Pb2 +性能的影响 ,得出了最佳去除效果的优化条件为 :废水的 pH值接近中性 ,吸附时间 10min。通过吸附实验 ,确定了在Pb2 +初始浓度为 2 0mg/L的条件下 ,13X沸石对Pb2 +的吸附量为 2 1 4 2mg/g ,即每克沸石净化含Pb2 +废水的最大体积量约为 75 0mL。解析实验表明 ,加入沉淀剂 ,浓缩洗脱液中的Pb2 +即以PbS的形式生成沉淀 ,为回收金属铅提供了可能 ;13X沸石在循环使用 5次的条件下 ,对废水中Pb2 +的吸附率仍高达 98% ,重复使用性能良好。经处理后的净化水中Pb2 +的浓度小于 0 4mg/L ,显著低于国家废水排放标准GB8978 88的指标 ( 1 0mg/L)。 13X沸石对Pb2 +的主要吸附形式是离子交换和表面络合反应。     

吗啉废水的生化处理工艺

以含有吗啉、甲基吗啉的高浓度有机废水为研究对象,提出了曝气吹脱-吸附-生物处理的联合工艺,并在室内进行了小试实验。结果表明：原废水经过2次曝气吹脱后,ρ(NH₃-N)从62 500 mg/L降为431 mg/L,ρ(COD)从50 840 mg/L降为26 051 mg/L。通过吸附实验,ρ(COD)从26 051 mg/L降为2 769 mg/L,ρ(NH₃-N)从412 mg/L降为134 mg/L。在生物处理室内小试实验中,采用了活性污泥反应器与曝气生物滤池相结合的处理工艺。在活性污泥反应系统中,当废水pH为7.5、ρ(DO)为4.3 mg/L、水力停留时间为30 h时,COD的去除率最高,可以达到83.1%。在曝气生物滤池中,当ρ(DO)为3.3 mg/L时,COD去除率最高,达到55.8%。在生物处理的最佳参数条件下进行连续监测,当进水ρ(COD)为2 769 mg/L、出水ρ(COD)平均值为387 mg/L时,COD去除率可达到85.9%。吗啉废水经过此联合工艺的处理,ρ(COD)从50 840 mg/L降为387 mg/L。