微生物菌剂复配及强化厨余垃圾好氧堆肥效果分析

厨余垃圾中有机组分的降解速率是影响其堆肥过程的重要因素。针对厨余垃圾中脂肪、蛋白质等特异组分设计了微生物菌剂复配方案,筛选了复配的微生物菌剂适宜接种量,并验证了厨余垃圾堆肥的强化效果。结果表明:厨余垃圾堆肥的适宜复配比为m(米曲霉)∶m(地衣芽孢杆菌)∶m(解脂假丝酵母)∶m(绿色木霉)∶m(褐球固氮菌)=1.5∶1∶1.2∶2∶1;且当接种量为6‰时,厨余垃圾中特异性组分脂肪降解率可达76.2%,氮损失率最低为11.8%。同时发现,固氮菌可以减少堆肥过程中氮素的损失,但固氮效果与初始加入固氮菌的量有关,且与菌剂间多种微生物的协作有关,进一步说明了微生物菌剂复配必要性和有效性。     

网络版论文摘要

<正>改性粉煤灰烧结陶粒吸附SO2的研究李英赞1宋元平2(1.吉林市环境保护监测站,吉林吉林132001;2.上海交通大学机械与动力工程学院,上海200240)采用热电厂粉煤灰为主要原料制备改性粉煤灰,以改性粉煤灰、膨润土、石灰石、水泥质量比为20∶2∶2∶1的比例     

粉煤灰-H2O2催化氧化水中对氨基苯酚的试验研究

研究了利用电厂粉煤灰作为非均相催化剂,催化H2O2氧化对氨基苯酚(PAP),讨论了各种因素对PAP去除率的影响.结果表明,在30℃,pH=1.5,H2O2和PAP的起始浓度分别为0.50 mol/L和0.10 mol/L,反应时间为100min,粉煤灰用量为6.0%,搅拌速度为1000r/min的条件下,粉煤灰具有良好的催化活性,能有效地催化H2O2氧化PAP,PAP的去除率可达81%左右.该法可用于预处理含PAP的工业废水.     

氨碱法制纯碱废渣制备免烧砖

利用氨碱法生产纯碱产生的废弃物——碱渣为主要原料制备免烧砖,研究了碱渣、粉煤灰、钢渣和石粉等不同含量对免烧砖强度的影响,优化了配比。研究表明:碱渣、粉煤灰、钢渣、石粉质量配比为4∶3∶2∶1时,免烧砖的7d和28d的抗压强度分别达到了14.0MPa和20.6MPa,吸水率为13.4%;扫描电镜表征结果,免烧砖内部颗粒分布均匀,界面结合良好;X-射线衍射表征其主要矿相为CaCO_3、Ca_2SiO_3Cl_2、Ca_3Si_6O_(12)(OH)_6·5H_2O。实验结果表明,免烧砖能有效利用碱渣,工艺简单,成本低。     

铁碳微电解/H_2O_2耦合类Fenton法深度处理制药废水

采用铁碳微电解/H2O2耦合类Fenton法深度处理制药废水,考察不同铁碳比、H2O2投加量、溶液p H及反应时间对COD去除效果的影响,通过单因素实验和正交实验确定最优条件并与铁碳微电解法的去除效果进行对比。结果表明,各因素对COD的去除效果均呈现先增加后降低或趋于稳定的趋势,且对去除效果的影响顺序为:Fe/CH2O2投加量溶液p H反应时间;在固液比为1∶10的条件下,Fe/C(质量比)为1∶1,溶液p H为2.5,反应时间为60 min,H2O2(30%)投加量为12.24 mmol/L时对COD的去除效率最高,可达71.56%;H2O2对铁碳微电解法有显著的加强作用。     

粉煤灰复合氧化钙去除铬渣渗滤液中的总铬

粉煤灰虽然具有较大的比表面积,但单独做为处理剂处理含铬废水,效果并不理想,具有吸附容量小、溶解损失大、且有毒性浸出等特点。为了解决粉煤灰以上缺陷,提出氧化钙复合粉煤灰去除铬渣渗滤液中总铬的技术,研究表明,在室温25℃条件下,总铬初始浓度在0.30~80.00 mg/L范围内,选择粉煤灰与Ca O配比为1∶1时,以150 r/min转速充分振荡24 h,总铬去除率均能达到90%以上。通过空白对照实验研究表明,粉煤灰复合Ca O使用,对总铬的去除远优于单独使用粉煤灰或Ca O做为吸附剂的处理效果。利用SEM,XRD,红外光谱分析3种材料表征方法,对粉煤灰原料、Ca O-粉煤灰处理后残渣等进行分析,结果表明,在水介质条件下,粉煤灰与Ca O能生成晶体矿物。当溶液中有铬存在时,晶体矿物在形成的过程中能将铬裹入其结构中。通过浸出实验表明,此晶体矿物对铬具有很好的固定作用。     

改性粉煤灰与过氧化氢联合作用深度处理皂素生产废水的研究

利用改性粉煤灰与过氧化氢(H2O2)联合的方法对二次处理过的皂素生产废水进行深度处理,研究了pH、改性粉煤灰投加量、H2O2投加量、反应时间对皂素生产废水脱色率和COD去除率的影响,分析了其作用机制.结果表明,试验最佳条件为:pH=6、反应时间60 min、改性粉煤灰投加量10 g/L、H2O2投加量4 mL/L.在最...     

新型微电解填料-Fenton联用处理硝基苯废水

研究通过单因素分析和正交实验法确定新型微电解填料-Fenton联用预处理硝基苯废水的最佳操作条件。结果表明,新型微电解填料降解硝基苯的影响因素从大到小依次为固液比>进水p H值>气水比>HRT,在微电解最佳条件:HRT为60 min,固液比为0.6,进水p H值为2,气水比为15∶1;Fenton试剂最佳条件:反应时间为20 min、p H值为4.5、m(H2O2):m(COD)为2.5、n(H2O2)∶n(Fe2+)为6,硝基苯和COD总去除率可分别达到97.6%和68.3%。处理后的废水可生化性提高,为后续的生物处理创造了良好的条件。     

含砷污泥的粉煤灰固化研究

硫酸废水处理系统的中和污泥属于有害废渣,其中As浸出率超标.采用固化的方法处理某冶炼厂硫酸废水中和污泥,发现以水泥∶粉煤灰∶污泥=1∶1∶2的配比固化后,固化块浸出液浓度达到国标规定(1.5 mg/L).研究表明,粉煤灰替代水泥50%可达到较好的固化效果,浸泡24 d后浸出浓度达到稳定值,pH值为7时浸出浓度最小,外加剂对固化有负影响,采用湿养护可获得更好的效果.     

矿山边坡绿化基质的优化配比

矿山边坡生态恢复和重建是矿区生态环境建设的有效途径,而绿化基质是矿山边坡生态恢复和重建的重要因素。基于正交实验和盆栽实验,以土壤、活性污泥、炉渣、粉煤灰、保水剂、尿素和秸秆等物质为基质原料,研究绿化基质的理化性质及出苗率特征。研究结果表明:与对照黄土相比,绿化基质pH相对较低,仍属于碱性土壤,而电导率、有机质和铵态氮相对较高,表明盐分和养分含量较高;污泥的配比含量是影响绿化基质入渗、蒸发、pH、电导率、有机质和出苗率等指标的关键因素;各因素对出苗率的影响强度从大到小依次为:污泥和粉煤灰、秸秆、土壤和炉渣、尿素、保水剂;基质的最优配比为:保水剂(11~15 g)、污泥和粉煤灰(150∶600)、土壤和炉渣(375∶375~600∶150)、尿素(0 g)、秸秆(30 g)。     

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)