RD复合净水剂对阳离子染料RL的吸附脱色

考察了RD复合净水剂吸附处理阳离子艳兰染料RL废液的实验条件,探讨了RD吸附脱色的实质。结果表明,加入0.3gRD到浓度为200mg/L的染液中,在25℃、pH=7.0条件下,吸附时间为10m in时,废液的脱色率达到80%,RD单位质量吸附量为10.7mg/g;当50mg/L的染料废液中,RD的投加量为0.2g时,脱色率达到了96%以上,RD单位质量吸附量为8.12mg/g;pH值和温度对吸附脱色效果影响不显著,而且RL废液的浓度增大,RD单位质量吸附量增大,但是脱色率有所下降。RD对染料的吸附符合Langmu ir吸附模型。     

蜂窝电话用锂离子电池的环境试验

国家标准GB/T18287-2000《蜂窝电话用锂离子电池总规范》中明确规定了锂离子电池的20℃常温,高温,恒定湿热性能,震动,碰撞,自由跌落等环境试验的具体方法及环境试验后的放电性能测试方法。     

用2-萘酚高盐废水浓缩液制备水泥减水剂

2-萘酚生产废液中含有多种有机化合物,直接排放会造成环境污染及资源浪费。为了保护环境,同时利用废液中的有机物资源,提出利用2-萘酚生产废液制备水泥减水剂的路线。实验测定了不同工艺条件对水泥净浆流动度的影响,得出合成萘磺酸甲醛缩合物的最优工艺条件为:总酸度为31%,甲醛进料温度85℃,甲醛与萘磺酸的摩尔比为1,缩合温度为115℃,缩合时间为5 h。     

柔性苯并咪唑钴有机骨架吸附刚果红研究

通过一个简单的合成方法制备了基于柔性苯并咪唑的含钴金属有机骨架[Co(L)(tp)]n(L=1,3-二(5,6-二甲基苯并咪唑基)丙烷,H2tp=对苯二甲酸),研究了该材料对刚果红的吸附作用和吸附模型。实验结果表明:pH为5.5,吸附剂浓度为0.16g/L,反应温度为45℃,吸附120min,刚果红溶液的脱除率接近100%。[Co(L)(bdc)]n对刚果红染料的吸附较好地符合Langmuir等温模型。     

活性炭纤维（ACF）脱硫动力学研究

本文在消除内外扩散的条件下对SO2－O2－N2－H2O（g）体系下,自制ACF脱除气相中二氧公硫的过程进行了动力学研究。认为在F＞400ml/min时可消除外扩散的影响。在空速为5000Nm3／tACF*h～24000Nm3／tACF*h,SO2浓度为0.1%～0.5%,氧浓度为1%～14%,反应温度为323K～403K,增湿温度在313K～363K之间探讨了温度、水、SO2及O2对ACF脱硫性能的影响,求出了反应动力学方程为rD＝0.006exp(-8852.8/RT)Cso20.4936Co20.7381CH2O0.7021。     

磺化石油焦酸催化剂的制备

以石油焦为原料、浓硫酸为磺化剂，通过磺化反应制得磺化石油焦酸催化剂。分析了制备条件的影响，获得了制备磺化石油焦的优化条件：反应温度120℃、反应时间30h、酸（摩尔）焦（g）比0．8mol／g。在优化条件下，磺化石油焦的交换容量可达2．6mmol／g。与强酸性阳离子交换树脂K2641相比，在相同的反应条件下，磺化石油焦作为酸催化剂催化合成乙酸乙酯表现出较高的催化活性，且重复使用5次后催化剂活性基本保持不变。     

三元锂离子电池正极材料浸出回收工艺进展

对从锂离子电池阴极材料中浸出回收有价金属的研究进行综述。从浸出试剂、浸出条件及机理方面分析了酸浸法、氨浸法和生物浸出等浸出方法对废旧锂离子电池阴极材料中金属的浸出效果。在还原剂存在条件下,无机酸能高效浸出阴极材料中有价金属;氨浸能选择性浸出金属。总结了各分离纯化工艺的优缺点,萃取能专一性地回收目标金属,沉淀法因工艺简单而广泛应用。综上,只有充分考虑各工艺优缺点,才能实现废旧锂离子电池的无害化回收。     

粉煤灰—膨润土颗粒吸附材料的制备及其处理含铅离子废水的研究

通过振荡吸附实验,研究了粉煤灰-膨润土颗粒吸附材料的制备方法及颗粒吸附材料在含铅离子废水中的吸附特性.结果表明,制备颗粒吸附剂的优化条件为:粉煤灰∶膨润土=5∶5(质量比),在600℃下焙烧2h.在温度25℃、pH值为5、Pb2+初始浓度为40mg/L、吸附剂用量为2g/L、吸附时间为1h条件下,吸附剂对废水中Pb2+的去除率可达95.27%.     

废锂离子电池的资源化利用及环境控制技术

随着电池在日常生活中的使用量越来越大,电池的产销量与日俱增,继而产生大量废弃电池的回收处理、处置问题。本文立足于废旧锂离子电池的循环利用,介绍了废锂离子电池的组成成分及当前国内外废旧电池的回收处理技术,以及由废旧电池到电池材料的"定向循环"技术,并针对在其循环利用过程中遇到的"重金属-氨氮复合废水"环境污染问题,提出了控制解决方法。     

硅铁粉制氢废液综合利用之——制备细孔硅胶

一、概述我国有的气象站和用硅铁粉与氢氧化钠的作用制备氢气,其化学反应可表示为:Si+2NaOH+H_2O70～80℃Na_2SiO_3+2H_2↑产生的氢气用来盛充氢气球,其余全作废液弃去了。由于该废液中含有未反应     

Nutrients and nonessential elements in soil after 11 years of wastewater irrigation

Irrigation of citrus (Citrus aurantium L. × Citrus paradise Macf.) with urban reclaimed wastewater (RWW) can be economical and conserve fresh water. However, concerns remain regarding its deleterious effects on soil quality. We investigated the ionic speciation (ISP) of RWW and potential impacts of 11 yr of irrigation with RWW on soil quality, compared with well-water (WW) irrigation. Most of nutrients (～53-99%) in RWW are free ionic species and readily available for plant uptake, such as: NH(4+), NO(3-), K(+), Ca(2+), Mg(2+), SO(4)(2-), H(3)BO(3), Cl(-), Fe(2+), Mn(2+), Zn(2+), Co(2+), and Ni(2+), whereas more than about 80% of Cu, Cr, Pb, and Al are complexed with CO(3-), OH(-), and/or organic matter. The RWW irrigation increased the availability and total concentrations of nutrients and nonessential elements, and soil salinity and sodicity by two to three times compared with WW-irrigated soils. Although RWW irrigation changed many soil parameters, no difference in citrus yield was observed. The risk of negative impacts from RWW irrigation on soil quality appears to be minimal because of: (i) adequate quality of RWW, according to USEPA limits; (ii) low concentrations of metals in soil after 11 yr of irrigation with RWW; and (iii) rapid leaching of salts in RWW-irrigated soil during the rainy season.     

Economies of scale for future lithium-ion battery recycling infrastructure

While lithium-ion battery (LIB) technology has improved substantially to achieve better performance in a wide variety of applications, this technological progress has led to a diverse mix of batteries in use that ultimately require waste management. Development of a robust end-of-life battery infrastructure requires a better understanding of how to maximize the economic opportunity of battery recycling while mitigating the uncertainties associated with a highly variable waste stream. This paper develops and applies an optimization model to analyze the profitability of recycling facilities given current estimates of LIB technologies, commodity market prices of materials expected to be recovered, and material composition for three common battery types (differentiated on the basis of cathode chemistry). Sensitivity analysis shows that the profitability is highly dependent on the expected mix of cathode chemistries in the waste stream and the resultant variability in material mass and value. The potential values of waste streams comprised of different cathode chemistry types show a variability ranging from $860 per ton¹ for LiMn₂O₄ cathode batteries to $8900 per ton for LiCoO₂ cathode batteries. In addition, these initial results and a policy case study can also help to promote end-of-life management and relative policymaking for spent LIBs.     

Assessment of Reclaimed Municipal Wastewater Application on Rice Cultivation

Field research was carried out to assess the effects of the application of reclaimed municipal wastewater on rice cultivation in Thessaloniki, Greece during a 2-year period (1999–2000). Effects on production cost, soil composition, and health risk were examined. A randomized complete block design was used for the paddy field with three treatments and four replicates. The treatments were (1) river irrigation water with N–P fertilization, (2) reclaimed wastewater irrigation with surface N fertilization, and (3) reclaimed wastewater irrigation without fertilization. The results showed that the total production cost decreased 8.8% and 11.9% by applying the second and third treatments, respectively, compared to the first treatment, without significant differences in the agronomic and rice quality traits. Soil composition showed discrepancies between the 2 years and the three treatments, whereas the pathogens of the reclaimed wastewater and rice tissues posed a low human risk when taking the needed precautions.     

Emergy evaluation of an integrated livestock wastewater treatment system

Wastewater treatment practices should pay more attention to their environmental performances due to their resources consumption and emissions’ impact. While reclaimed water reuse seems to have become a promising practice, is it always feasible in any condition? To address this issue, this study carried out an extended emergy evaluation of a holistic wastewater treatment system. On one hand, this method was extended to include the emissions’ impact. On the other hand, this study integrated a wastewater treatment plant, its excess sludge disposal system and treated water disposal system into an integrated wastewater treatment system (IWTS), so as to evaluate its performances more completely. And then several indicators, including cost per unit pollutant eliminated (CUPE), ratio of positive output (RPO), environmental load ratio (ELR), and sustainability index (SI), were proposed for evaluating the performances of an IWTS. Two scenarios (scenario A: wastewater treatment + sludge landfilling + treated water discharges; scenario B: wastewater treatment + sludge landfilling + reclaimed water reuse) for a livestock wastewater treatment plant in Sichuan Agricultural University located in Ya’an City in Southwest China, as cases, were researched. The results show that scenario B has lower positive output efficiency and greater environmental load than scenario A. Meanwhile, the reclaimed water reuse raises cost per unit pollutant eliminated compared with the treated water being discharged directly; emissions’ impact enhances the environmental load of the two scenarios to different degree; emissions’ impact has decisive effect on the sustainability of the two scenarios. These results mean that the reclaimed water reuse should not be advocated in this case. This study provides some policy implications: (1) wastewater treatment process should be comprehensively evaluated from its resources consumption and impact of emissions; (2) reclaimed water reuse should be carefully evaluated from its pros and cons simultaneously; (3) the local conditions should be considered when implementing reclaimed water reuse, such as local water body conditions, market demands, the related laws and regulations, corporations’ economic conditions, etc.     

Synthesis and characterization of multi-walled carbon nanotubes from silkworm cocoons to use as the cathode material for Al-air battery

ABSTRACT

Carbon nanotubes have been synthesized by chemical vapor deposition at 850°C using silkworm cocoons as a precursor. The impregnation method with 3 wt% ferrocene as a catalyst was utilized for growth of carbon nanotubes. The flow rates of C₂H₂, H₂, and N₂ were fixed at 100, 150, and 350 ml/min, respectively. Morphology, microstructure and quality of the synthesized carbon nanotubes were investigated by scanning electron microscopy, transmission electron microscopy, and Raman spectroscopy techniques. Results showed that the prepared carbon nanotubes were multiwalled and good graphitic quality. When used as the cathode material for aluminum-air battery, prepared carbon nanotubes cathode exhibited higher current density than commercial graphite cathode. Based on our study, there is a successful conversion of silkworm cocoons into value-added nanomaterial products, promoting the natural biotechnological materials.     

An Aquifer Storage and Recovery system with reclaimed wastewater to preserve native groundwater resources in El Paso, Texas

The traditional concept of Aquifer Storage and Recovery (ASR) has been emphasized and extensively applied for water resources conservation in arid and semi-arid regions using groundwater systems as introduced in Pyne's book titled Groundwater Recharge and Wells. This paper extends the ASR concept to an integrated level in which either treated or untreated surface water or reclaimed wastewater is stored in a suitable aquifer through a system of spreading basins, infiltration galleries and recharge wells; and part or all of the stored water is recovered through production wells, dual function recharge wells, or by streams receiving increased discharge from the surrounding recharged aquifer as needed. In this paper, the author uses the El Paso Water Utilities (EPWU) ASR system for injection of reclaimed wastewater into the Hueco Bolson aquifer as an example to address challenges and resolutions faced during the design and operation of an ASR system under a new ASR system definition. This new ASR system concept consists of four subsystems: source water, storage space-aquifer, recharge facilities and recovery facilities. Even though facing challenges, this system has successfully recharged approximately 74.7 million cubic meters (19.7 billion gallons) of reclaimed wastewater into the Hueco Bolson aquifer through 10 recharge wells in the last 18 years. This ASR system has served dual purposes: reuse of reclaimed wastewater to preserve native groundwater, and restoration of groundwater by artificial recharge of reclaimed wastewater into the Hueco Bolson aquifer.     

Regeneration of industrial district wastewater using a combination of Fenton process and ion exchange—A case study

Regeneration studies of wastewater effluent from an organized industrial district (OID) for possible reuse in textile industry as process water was investigated. Advanced treatment methods including Fenton process, polyaluminium chloride (PAC) coagulation and ion exchange were applied on OID effluent. In Fenton process removal efficiencies for suspended solids (SS), chemical oxygen demand (COD), SAC₄₃₆ (spectral absorption coefficient), SAC₅₂₅ and SAC₆₂₀ were determined 61%, 36%, 35%, 49% and 67%, respectively. After Fenton process, wastewater samples were coagulated with PAC. Optimum removal efficiencies for SS, COD, Fe ion, SAC₄₃₆, SAC₅₂₅ and SAC₆₂₀ were determined 83%, 18%, 93%, 32%, 36% and 58%, respectively. Ion exchange experiments were conducted on chemically coagulated wastewater samples to improve the quality of wastewater. Optimum dosage of resins was determined. The experiments revealed that 1:1 resin ratio (20 mL H-type resin:20 mL OH-type resin) gave the best removal rates for the parameters considered in this study. Study results indicated that quality of the wastewater was suitable for the process water characteristics of textile industry and unit wastewater treatment cost was determined as 2.54 €/m³.     

Application of groundwater thresholds for trace elements on percolation water: a case study on percolation water from Northern German lowlands

The German insignificance thresholds (GFS) for groundwater, derived with an added risk approach, will soon be adopted as trigger values for percolation water entering groundwater. The physicochemical properties of the vadose zone differ considerably from those of groundwater, which may lead to difficulties in the applicability of groundwater-derived GFS to percolation water. To test the applicability of the GFS to percolation water regarding the concentration level and the field-scale variability, 46 sites in Northern Germany were sampled, including arable land, grassland, and forest, situated on three spatially dominant parent materials: sand, glacial loam, and loess. Concentrations of As, Ba, Cd, Co, Cr, Cu, Mo, Ni, Pb, Sb, Sn, V, Zn, and F were analyzed in percolation water from the transition between the unsaturated to the saturated zone. We compared median and 90th percentile values of the background concentrations with the GFS. In more than 10% of all samples, background concentrations of Cd, Co, Ni, V, or Zn exceeded the GFS. We evaluated the applicability of the GFS on field-scale medians of background concentrations taking field-scale interquartile distance and the bootstrap percentile confidence interval of the field scale median of trace element background concentrations into consideration. Statements about exceedance or nonexceedance of GFS values could only be made with acceptable statistical uncertainty (α ≤ 0.1) when operational median concentrations were about one third higher or lower than the corresponding GFS.     

珠江三角洲经济区污水系统设计原则

分析了珠江三角洲经济区水环境现状；阐述了城市污水分散处理与集中处理的利弊；指出污水深度处理与回用是形成良性水循环的有效途径，更是经济可持续发展的必然要求；通过对已建排水系统存在问题的分析，探讨了珠江三角洲经济开发区污水系统的设计原则，认为污水系统规划要改变传统设计方法，应方便再生水回用，由经济、技术、地理等综合因素确定排水分区、污水厂厂址与数量，选择适合各排水区域水质水量的工艺流程，预留污水厂与再生水回用管线分期发展的空间，应优先选用国产污水处理设备，尽可能维持城市河涌自然生态。     

Total Contents and Sequential Extraction of Heavy Metals in Soils Irrigated with Wastewater,Akaki, Ethiopia

The Akaki River, laden with untreated wastes from domestic, industrial, and commercial sources, serves as a source of water for irrigating vegetable farms. The purpose of this study is to identify the impact of waste-water irrigation on the level of heavy metals and to predict their potential mobility and bioavailability. Zn and V had the highest, whereas Hg the lowest, concentrations observed in the soils. The average contents of As, Co, Cr, Cu, Ni, Zn, V, and Hg of both soils; and Pb and Se from Fluvisol surpassed the mean + 2 SD of the corresponding levels reported for their uncontaminated counterparts. Apparently, irrigation with waste water for the last few decades has contributed to the observed higher concentrations of the above elements in the study soils (Vertisol and Fluvisol) when compared to uncontaminated Vertisol and Fluvisol. On the other hand, Vertisol accommodated comparatively higher average levels of Cr, Cu, Ni, Zn, etc V, and Cd, whereas high contents of Pb and Se were observed in Fluvisol. Alternatively, comparable levels of Co and Hg were found in either soil. Except for Ni, Cr, and Cd in contaminated Vertisol, heavy metals in the soils were not significantly affected by the depth (0–20 and 30–50 cm). When the same element from the two soils was compared, the levels of Cr, Cu, Ni, Pb, Se, Zn, V, Cd at 0–20 cm; and Cr, Ni, Cu, Cd, and Zn at 30–50 cm were significantly different. Organic carbon (in both soils), CEC (Fluvisol), and clay (Vertisol) exhibited significant positive correspondences with the total heavy metal levels. Conversely, Se and Hg contents revealed perceptible associations with carbonate and pH. The exchangeable fraction was dominated by Hg and Cd, whereas the carbonate fraction was abounded with Cd, Pb, and Co. conversely, V and Pb displayed strong affinity to reducible fraction, where as Cr, Cu, Zn, and Ni dominated the oxidizable fraction. Cr, Hg, Se, and Zn (in both soils) showed preference to the residual fraction. Generally, a considerable proportion of the total levels of many of the heavy metals resided in non residual fractions. The enhanced lability is generally expected to follow the order: Cd > Co > Pb > Cu > Ni > Se > V and Pb > Cd > Co > Cu > Ni > Zn in Vertisol and Fluvisol, respectively. For the similar wastewater application, the soil variables influence the status and the distribution of the associated heavy metals among the different soil fractions in the study soils. Among heavy metals that presented relatively elevated levels and with potential mobility, Co, Cu, Ni (either soil), V (Vertisol), Pb, and Zn (Fluvisol) could pose health threat through their introduction into the food chain in the wastewater irrigated soils.