石煤渣制橡胶填料的研究

以钛酸酯偶联剂为表面处理剂,对石煤渣进行表面改性处理,制得橡胶填料,测试了该填料对橡胶的补强作用,并与陶土、碳酸钙、炭黑等填料的补强性能进行了比较。实验表明,表面改性后的石煤渣填料对橡胶具有较好的补强作用,可完全替代碳酸钙、碳酸镁或陶土,产生较好的补强效果,用替代部分炭黑,可以减少炭黑用量,降低橡胶成本。     

新型管式微孔曝气器性能研究

以废旧橡胶为主要原料研制的微孔曝气器,传质效率高,曝气充氧性能优良,搅拌能力强;沿管长方向具有很好的均匀布气性,输气曝气合二为一;制造工艺简单,价格低廉,安装方便;拓展了废旧橡胶的综合利用途径,以废治废,减少了废旧橡胶对环境的污染。     

填料床处理污染河水的冬季运行特性

对冬季填料床处理滇池流域污染河水进行了试验研究。结果表明：通过相关性分析可知,在2～6℃时,废砖块中微生物活性较低,温度回升后,微生物活性也随之增强;2～12℃时,废混凝土/沸石/煤渣组合生物量高,耗氧速率大且较为稳定,COD去除率保持在50%左右。降温期（5～12℃）时,废砖块对TN、NH⁺₄-N和DTP去除率最高,平均可达64.5%、64.7%和69.7%;低温期（2～6℃）时,废混凝土/沸石/煤渣组合对NH⁺₄-N、TN的去除率能达到56.4%～75.1%、56.5%～63.0%,大石子/小石子/煤渣组合削减DTP负荷量达到了2.1 g/(m²·d)。废砖块和大石子/小石子/煤渣组合分别适合在低负荷和高负荷下运行。综上所述,在整个试验过程中（2～12℃）,废混凝土/沸石/煤渣组合表现出了对COD、N和DTP去除率相对稳定的特征,是冬季处理滇池流域污染河水的适宜填料。     

废塑料制造水泥减水剂

中国科学院兰州分院研发成功废塑料制造水泥减水剂技术,从而使通常称作“白色污染”的废塑料变成环保型产品。水泥减水剂是用于水泥混凝土拌制的一种添加剂,既可减少混凝土拌制时的用水量,提高混凝土的强度,又可使混凝土保持较好的流动性。该技术利用废旧聚苯乙烯泡沫塑料,经过化学预处理后,加入有机溶剂和填料,制造成高效减水剂。检测表明,使用该减水剂后,混凝土各项技术指标达到和部分超过国标一等品水平,具有广阔的市场前景。     

自来水厂污泥制得陶粒对污水中磷和氨氮的吸附

自来水厂在制水过程中使用了铝系、铁系无机混凝剂,故而污泥中含有较多的铝、铁成分。本研究从固体废物综合利用角度,结合自来水厂污泥成分特点,探索自来水厂污泥陶粒化后作为污水处理污染物吸附填料的可行性。通过对四种不同温度条件下煅烧制得陶粒填料的污染物吸附性能及物理化学特征的对比研究表明,4种陶粒填料对磷均有较好的吸附效果,其中以400℃条件下制得的吸附效果最好,去除率可达98%;EDS、XRD等物化表征显示了4种陶粒填料中均含有铝的氧化物,但纯度不高,含量因煅烧温度不同而有所不同,800℃条件下制得的最低;比较吸附前后填料中Al-P的含量变化,400℃条件下制得的陶粒填料Al-P吸附量最大,达448.23 mg/kg,而800℃的最低,仅为116.11 mg/kg,煅烧后陶粒中铝氧化物是这类陶粒填料对磷吸附效果主要因素。     

生活垃圾制造地板砖

上海天南垃圾工程有限公司开发成功垃圾利用的专利技术。该技术将生活垃圾经过一系列除臭、粉碎、杀菌、搅拌和生物试剂及辅料混合，再由多功能制砖机制成各种地板砖、路基砖、图形墙体板等建筑材料，整个生产过程在常温下进行，不产生二次污染。该技术对废弃物要求低，几乎涵盖了任何生活废弃物，包括废水泥、废砖瓦、塑料、玻璃、木材、橡胶、果皮纸张、甚至沙石。不同材料经过分选，可制成高档的材料，如耐火砖、人工大理石等，也可以不经分选，直接制成低档产品，如人行道地砖。经权威部门检测，制得的产品无毒、无味、无菌、强度高、硬度大，产品质量甚至超过一般建筑材料技术标准，可取代一般建筑材料，但成本仅为一般建筑材料的70％～80％。     

废铸砂作为建筑材料资源化再利用研究进展

废铸砂是铸造工业在金属制品的生产过程中次生出来的一种细颗粒固体废弃物。研究其作为一种资源进行合理再利用是当前处置废铸砂、保护生态环境的良好对策。本文对废铸砂的环境特征、物理性质及废铸砂作为建筑材料在多种建筑制品及工程中的资源化再利用进行了综述研究,涉及的再利用领域包括混凝土、热拌沥青混合料、低强度填料、水泥、路基、路堤、阻水帷幕（屏障）和衬垫。调查发现,次生于黑色金属（铁和钢）铸造生产线的废铸砂是一种无害固体废弃物,正确处置和科学利用,对环境不会产生二次污染,在以上建筑制品及工程中的应用能满足相关技术、性能要求,可以替代相关的材料进行资源化再利用。     

序批式生物膜反应器处理农村生活污水的填料对比研究

选用4种填料进行序批式生物膜反应器(SBBR)处理农村生活污水的研究,通过出水COD、NH4+-N等指标的测定以及生物膜的扫描电镜观察,考察了运用不同填料时SBBR的污染物去除情况和生物膜的长势,以期筛选出适用于农村生活污水处理的填料。结果表明,3#、4#SBBR(分别选用组合填料和碳素纤维填料)的DO、pH波动幅度均相对较小,比1#、2#SBBR(分别选用立体网状填料及海绵填料)更加稳定;4#SBBR的COD去除效果最好,水力停留时间仅需5h,3#SBBR的COD去除效果其次,所需水力停留时间为6h,而1#、2#SBBR在运行8h时也无法将COD完全消化;3#、4#SBBR出水的NH4+-N、TN去除效果均高于1#、2#SBBR;采用4种填料的SBBR的生物膜长势优劣情况为碳素纤维填料>组合填料>海绵填料>立体网状填料;碳素纤维填料及组合填料在受到进水负荷冲击后,能相对较快适应环境,且填料上的微生物活性较高,较适合运用于中国农村生活污水的处理。     

3种固定式填料在中试IFAS系统中的性能比较及菌群结构解析

为考察固定式填料在生物膜-活性污泥工艺(IFAS)中的性能和菌群结构,选取弹性立体填料、组合填料以及自制填料3种固定式填料投入中试级别的IFAS反应器好氧池中进行对比,另于小试系统中进行3种填料的脱膜实验。结果表明:组合填料的亲水性最高(接触角为38°),生物膜厚且致密,加上结点的存在,易结团,脱膜率最高为63%;弹性填料21 d基本可以完成生物膜的更新;而自制填料脱膜速率先快后慢,第24天时脱膜率高达80%。在系统运行期间,3种填料对COD、氨氮去除率均在90%以上,出水均达到一级A排放标准。自制填料和组合填料系统的总氮去除率高于弹性填料。当自制填料系统运行27 d以后,TN出水可稳定达到一级A排放标准。与组合填料和弹性填料相比,由于自制填料结构的特殊性,其负载的生物量最多,生物多样性最高,同时,对硝化细菌、反硝化菌和反硝化除磷菌均表现出富集优势。     

废水处理用生物填料的研究进展

概述了废 (污 )水处理用生物填料的现状和发展 ,并针对现今水处理用生物填料存在的亲水性和生物亲和性(活性 )不足这一问题 ,提出了解决办法和发展方向 ,指出生物亲和亲水活性磁种填料的应用 ,可望大大提高废水生物降解的效率。     

Chloroaromatic pollutants in mussels incubated in two finnish watercourses polluted by industry

Concentrations of different chlorinated compounds were measured in mussels incubated in two polluted watercourses, a river (the River Kymijoki) and a lake (Lake Vanaja) for four weeks in summer 1995. The sum concentrations of polychlorinated phenols (PCP) and biphenyls (PCB) were both about 1 μg/g lipid weight (lw) in Lake Vanaja mussels, while in the River Kymijoki mussels PCPs were non-detectable and PCBs were measured 120 ng/g lIw. The concentrations of toxic polychlorinated dibenzo-p-dioxin (PCDD) and dibenzofuran (PCDF) congeners ranged between <17 and 370 pg/g Iw in Lake Vanaja mussels and between <38 and 11,000 pg/g lw in the River Kymijoki mussels. Polychlorinated diphenyl ethers (PCDE) were detected in the mussels incubated in the River Kymijoki (0.4–1.1 ng/g Iw), but not in those incubated in Lake Vanaja. Polychlorinated phenoxyanisoles (PCPA) were measured 33 ng/g lw and polychlorinated phenoxyphenols (PCPP) 300 ng/g lw in the mussels incubated in the River Kymijoki. PCPAs were also detected in reference samples, which were sediment and pike from the River Kymijoki and Baltic salmon, seal and white-tailed sea eagle.     

Book review

The Pesticide Manual ‐ A World Compendium, 8th Edition, C.R. Worthing, Editor and S.B. Walker, Assistant Editor, British Crop Protection Council, BCPC Publications Sales, Bear Farm, Binfield, Bracknell, Berkshire RG12 5QE, England. 1987, 1100 pp., UK £50; Overseas £56. ISBN 0–948404–01–9.     

Organochlorine compounds in a three-step terrestrial food chain

The concentrations of 15 organochlorine chemicals (PCBs and pesticides) were studied in a Central European oak wood food chain system: Great tit (Parus major), caterpillars (Tortrix viridana, Operophtera brumata, Erannis defoliaria), and oak-leaves (Quercus robur). Juvenile tits receive organochlorines from the mother via egg transfer and, eventually to a greater extent, from the caterpillar food source during nestling period. The concentrations of PCB 153 (2,2′,4,4′,5,5′-hexachlorobiphenyl, the most abundant in this study) was found in leaf material at ca. 1 ng/g, in caterpillars 10 ng/g, and in bird eggs 170 ng/g on an average and on a dry mass basis.     

The chemical stability of formulations of some hydrolyzable insecticides in aqueous mixtures with hydrolysis catalysts

Abstract

The active ingredients in commercial formulations of malathion, oxamyl, carbaryl, diazinon, and chlorpyrifos diluted to “spray tank”; concentrations with buffered distilled or natural water of pH 4–9 were stable for at least 24 hr. Formulations of trichlorfon were not stable at pH 7 or above but disappearance rates were slower than for the pure chemical in homogeneous solution. Cupric ion was observed to be an effective catalyst for the hydrolysis of a variety of pure organophosphorus insecticides but did not catalyze hydrolysis of the active ingredients of the formulations examined. Increasing the dilution of the formulation increased the susceptibility of malathion, oxamyl, and carbaryl to hydrolysis.     

Observations on the influence of water and soil pH on the persistence of insecticides

Abstract

The pH‐disappearance rate profiles were determined at ca. 25°C for 24 insecticides at 4 or 5 pH values over the range 4.5 to 8.0 in sterile phosphate buffers prepared in water‐ethanol (99: 1 v/v). Half‐lives measured at pH 8 were generally smaller than at lower pH values. Changes in half lives between pH 8.0 and 4.5 were largest (>1000x) for the aryl carbamates, carbofuran and carbaryl, the oxime carbamate, oxamyl, and the organophosphorus insecticide, trichlorfon. In contrast, half lives of phorate, terbufos, heptachlor, fensulfothion and aldicarb were affected only slightly by pH changes. Under the experimental conditions described half lives at pH8 varied from 1–2 days for trichlorfon and oxamyl to >1 year for fensulfothion and cyper‐methrin. Insecticide persistence on alumina (acid, neutral and basic), mineral soils amended with aluminum sulfate or calcium hydroxide to different pH values and four natural soils of different pH was examined. No correlation was observed between the measured pH of these solids and the rate of disappearance of selected insecticides applied to them. These observations demonstrate the difficulty of extrapolating the pH dependent disappearance behaviour observed in homogeneous solution to partially solid heterogeneous systems such as soil.     

Evaluation of trichloroethene recovery processes in heterogeneous aquifer cells flushed with biodegradable surfactants

The ability of two biodegradable surfactants, polyoxyethylene (20) sorbitan monooleate (Tween 80) and sodium dihexyl sulfosuccinate (Aerosol MA), to recover a representative dense non-aqueous-phase liquid (DNAPL), trichloroethene (TCE), from heterogeneous porous media was evaluated through a combination of batch and aquifer cell experiments. An aqueous solution containing 3.3% Aerosol MA, 8% 2-propanol and 6 g/l CaCl(2) yielded a weight solubilization ratio (WSR) of 1.21 g TCE/g surfactant, with a corresponding liquid-liquid interfacial tension (IFT) of 0.19 dyn/cm. Flushing of aquifer cells containing a TCE-DNAPL source zone with approximately two pore volumes of the AMA formulation resulted in substantial (>30%) mobilization of TCE-DNAPL. However, a TCE mass recovery of 81% was achieved when the aqueous-phase flow rate was sufficient to displace the mobile TCE-DNAPL toward the effluent well. Aqueous solutions of Tween 80 exhibited a greater capacity to solubilize TCE (WSR=1.74 g TCE/g surfactant) and exerted markedly less reduction in IFT (10.4 dyn/cm). These data contradict an accepted empirical correlation used to estimate IFT values from solubilization capacity, and indicate a unique capacity of T80 to form concentrated TCE emulsions. Flushing of aquifer cells with less than 2.5 pore volumes of a 4% T80 solution achieved TCE mass recoveries ranging from 66 to 85%, with only slight TCE-DNAPL mobilization (<5%) occurring when the total trapping number exceeded 2 x 10(-5). These findings demonstrate the ability of Tween 80 and Aerosol MA solutions to efficiently recover TCE from a heterogeneous DNAPL source zone, and the utility of the total trapping number as a design parameter for a priori prediction of DNAPL mobilization and bank angle formation when flushing with low-IFT solutions. Given their potential to stimulate microbial reductive dechlorination at low concentrations, these surfactants are well-suited for remedial action plans that couple aggressive mass removal followed by enhanced bioremediation to treat chlorinated solvent source zones.     

Radionuclides in pinon pine (Pinus edulis) nuts from los alamos national laboratory lands and the dose from consumption

Abstract

One of the dominant tree species growing within and around the eastern portion of Los Alamos National Laboratory (LANL), Los Alamos, NM, lands is the pinon pine (Pinus edulis). Pinon pine is used for firewood, fence posts, and building materials and is a source of nuts for food—the seeds are consumed by a wide variety of animals and are also gathered by people in the area and eaten raw or roasted. This study investigated the (1) concentration of ³H, ¹³⁷Cs, ⁹⁰Sr, ^totU, ²³⁸Pu, ^{239, 240}Pu, and²⁴¹ Am in soils (0‐ to 12‐in. [31 cm] depth underneath the tree), pinon pine shoots (PPS), and pinon pine nuts (PPN) collected from LANL lands and regional background (BG) locations, (2) committed effective dose equivalent (CEDE) from the ingestion of nuts, and (3) soil to PPS to PPN concentration ratios (CRs). Most radionuclides, with the exception of ³H in soils, were not significantly higher (p < 0.10) in soils, PPS, and PPN collected from LANL as compared to BG locations, and concentrations of most radionuclides in PPN from LANL have decreased over time. The maximum net CEDE (the CEDE plus two sigma minus BG) at the most conservative ingestion rate (10 lb [4.5 kg]) was 0.0018 mrem (0.018 μSv); this is far below the International Commission on Radiological Protection (all pathway) permissible dose limit of 100 mrem (1000 μSv). Soil‐to‐nut CRs for most radionuclides were within the range of default values in the literature for common fruits and vegetables.     

Degradation and sorption of imidacloprid in dissimilar surface and subsurface soils

Degradation and sorption/desorption are important processes affecting the leaching of pesticides through soil. This research characterized the degradation and sorption of imidacloprid (1-[(6-chloro-3-pyridinyl)-methyl]-N-nitro-2-imidazolidinimine) in Drummer (silty clay loam) and Exeter (sandy loam) surface soils and their corresponding subsurface soils using sequential extraction methods over 400 days. By the end of the incubation, approximately 55% of imidacloprid applied at a rate of 1.0 mg kg^?1 degraded in the Exeter sandy loam surface and subsurface soils, compared to 40% of applied imidacloprid within 300 days in Drummer surface and subsurface soils. At the 0.1 mg kg^?1 application rate, dissipation was slower for all four soils. Water-extractable imidacloprid in Exeter surface soil decreased from 98% of applied at day 1 to > 70% of the imidacloprid remaining after 400 d, as compared to 55% in the Drummer surface soil at day 1 and 12% at day 400. These data suggest that imidacloprid was bioavailable to degrading soil microorganisms and sorption/desorption was not the limiting factor for biodegradation. In subsurface soils > 40% of ¹⁴C-benzoic acid was mineralized over 21 days, demonstrating an active microbial community. In contrast, cumulative ¹⁴CO₂ was less than 1.5% of applied ¹⁴C-imidacloprid in all soils over 400 d. Qualitative differences in the microbial communities appear to limit the degradation of imidacloprid in the subsurface soils.     

Biochemical interaction of six op delayed neurotoxicants with several neurotargets

Abstract

Five organophosphorous insecticides: Leptophos, EPN, Cyano‐fenphos, trichloronate and salithion proved to cause irreversible ataxia not only to chicken but also to mice and sheep. TOCP was included as a reference. Cyanofenphos blocked the catecholamine B‐receptor binding activity with ³H‐norepinephrine at a level similar to that of the specific inhibitor propranolol in the mouse heart preparation. In the lamb heart preparation, the B‐receptor was more sensitive to Leptophos, salithion and TOCP than to propranolol. The six compounds and their oxons were screened for their in‐vitro inhibition to monamine oxidase (MAO), acetyl cholinesterase (AChE) and neurotoxic esterase (NTE) in the brain of either mouse, lamb or chicken. It is believed that their AChE inhibition stands for their acute toxicity, while NTE inhibition is responsible for their paralytic ataxia.     

Phytoextraction of lead-contaminated soil using vetivergrass (<Emphasis Type="Italic">Vetiveria zizanioides</Emphasis> L.), cogongrass (<Emphasis Type="Italic">Imperata cylindrica</Emphasis> L.) and carabaograss (<Emphasis Type="Italic">Paspalum conjugatum</Emphasis> L.)

Background, Aims and Scope The global problem concerning contamination of the environment as a consequence of human activities is increasing. Most of the environmental contaminants are chemical by-products and heavy metals such as lead (Pb). Lead released into the environment makes its way into the air, soil and water. Lead contributes to a variety of health effects such as decline in mental, cognitive and physical health of the individual. An alternative way of reducing Pb concentration from the soil is through phytoremediation. Phytoremediation is an alternative method that uses plants to clean up a contaminated area. The objectives of this study were: (1) to determine the survival rate and vegetative characteristics of three grass species such as vetivergrass, cogongrass and carabaograss grown in soils with different Pb levels; and (2) to determine and compare the ability of the three grass species as potential phytoremediators in terms of Pb accumulation by plants. Methods The three test plants: vetivergrass (Vetiveria zizanioides L.); cogongrass (Imperata cylindrica L.); and carabaograss (Paspalum conjugatum L.) were grown in individual plastic bags containing soils with 75 mg kg⁻¹ (37.5 kg ha⁻¹) and 150 mg kg⁻¹ (75 kg ha⁻¹) of Pb, respectively. The Pb contents of the test plants and the soil were analyzed before and after experimental treatments using an atomic absorption spectrophotometer. This study was laid out following a 3 × 2 factorial experiment in a completely randomized design. Results On the vegetative characteristics of the test plants, vetivergrass registered the highest whole plant dry matter weight (33.85–39.39 Mg ha⁻¹). Carabaograss had the lowest herbage mass production of 4.12 Mg ha⁻¹ and 5.72 Mg ha⁻¹ from soils added with 75 and 150 mg Pb kg⁻¹, respectively. Vetivergrass also had the highest percent plant survival which meant it best tolerated the Pb contamination in soils. Vetivergrass registered the highest rate of Pb absorption (10.16 ± 2.81 mg kg⁻¹). This was followed by cogongrass (2.34 ± 0.52 mg kg⁻¹) and carabaograss with a mean Pb level of 0.49 ± 0.56 mg kg⁻¹. Levels of Pb among the three grasses (shoots + roots) did not vary significantly with the amount of Pb added (75 and 150 mg kg⁻¹) to the soil. Discussion Vetivergrass yielded the highest biomass; it also has the greatest amount of Pb absorbed (roots + shoots). This can be attributed to the highly extensive root system of vetivergrass with the presence of an enormous amount of root hairs. Extensive root system denotes more contact to nutrients in soils, therefore more likelihood of nutrient absorption and Pb uptake. The efficiency of plants as phytoremediators could be correlated with the plants’ total biomass. This implies that the higher the biomass, the greater the Pb uptake. Plants characteristically exhibit remarkable capacity to absorb what they need and exclude what they do not need. Some plants utilize exclusion mechanisms, where there is a reduced uptake by the roots or a restricted transport of the metals from root to shoots. Combination of high metal accumulation and high biomass production results in the most metal removal from the soil. Conclusions The present study indicated that vetivergrass possessed many beneficial characteristics to uptake Pb from contaminated soil. It was the most tolerant and could grow in soil contaminated with high Pb concentration. Cogongrass and carabaograss are also potential phytoremediators since they can absorb small amount of Pb in soils, although cogongrass is more tolerant to Pb-contaminated soil compared with carabaograss. The important implication of our findings is that vetivergrass can be used for phytoextraction on sites contaminated with high levels of heavy metals; particularly Pb. Recommendations and Perspectives High levels of Pb in localized areas are still a concern especially in urban areas with high levels of traffic, near Pb smelters, battery plants, or industrial facilities that burn fuel ending up in water and soils. The grasses used in the study, and particularly vetivergrass, can be used to phytoremediate urban soil with various contaminations by planting these grasses in lawns and public parks. ESS-Submission Editor: Dr. Willie Peijnenburg (wjgm.peijnenburg@rivm.nl)