Modification of Soy Protein Plastic with Functional Monomer with Reactive Extrusion

Chemical modification of soy protein with monomers such as maleic anhydride, glycidyl methacrylate and styrene was accomplished using reactive extrusion technology. Thermal and mechanical properties of the modified soy protein plastics were characterized with differential scanning calorimetry (DSC), a dynamic mechanical analyzer (DMA) and a United Testing System load frame. It was found that the denaturation temperature and the glass transition temperature of soy protein plastic changed. In addition, the tensile properties of modified soy protein plastic improved. Attenuated total reflection Fourier transform infrared (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS) were used to characterize the structure of modified soy proteins. A suggestion of the interaction between soy protein and functional group in functional polymers is given. Through the in-situ interaction between the polymer and soy protein plastic, the mechanical properties of the soy protein plastic can be adjusted and controlled.     

Fertilization of maize with compost from cattle manure supplemented with additional mineral nutrients

An alternative approach for cattle manure management on intensive livestock farms is the composting process. An industrial-scale composting plant has been set up in northwest Spain for producing compost from cattle manure. Manure composting involved an increase in pH, electrical conductivity (EC), cation exchange capacity (CEC) and NO3(-)--N concentration, and a decrease in temperature, moisture content, organic matter (OM) content, NH4+--N concentration and C/N ratio. Cu, Zn and Ni concentrations increased due to the reduction of pile mass during the composting process. The resulting compost was applied to a field to study the viability of applying this compost combined with a nitrogen mineral fertilizer as a replacement for the mineral fertilization conventionally used for maize (Zea mays L.). The thermophilic phase of the composting process was very prolonged in the time, which may have slowed down the decomposition of the organic matter and reduced the nitrification process, leading to an over-short maturation phase. The humification and respirometric indexes, however, determined immediately after compost application to the soil, showed it to be stable. Compost application did not decrease the grain yield. A year later, soil pH, OM content and CEC were higher with the compost treatment. Total P, K, Ca and Na concentrations in compost-amended plots were higher than in mineral-fertilized ones, and no significant differences between treatments were found in soil concentrations of NH4+--N,NO3- --N, available P, Mg and B. Compost caused no heavy metal pollution into the soil. Therefore, this compost would be a good substitute for the mineral fertilizers generally used for basal dressing in maize growing.     

Overview of waste stabilization with cement

Cement can treat a variety of wastes by improving physical characteristics (solidification) and reducing the toxicity and mobility of contaminants (stabilization). Potentially adverse waste-binder interactions are an important consideration because they can limit solidification. Stabilization occurs when a contaminant is converted from the dissolved (mobile) phase to a solid (immobile) phase by reactions, such as precipitation, sorption, or substitution. These reactions are often strongly affected by pH, so the presence of components of the waste that control pH are critical to stabilization reactions. Evaluating environmental impacts can be accomplished in a tiered strategy in which simplest approach would be to measure the maximum amount of contaminant that could be released. Alternatively, the sequence of release can be determined, either by microcosm tests that attempt to simulate conditions in the disposal zone or by mechanistic models that attempt to predict behavior using fundamental characteristics of the treated waste.     

Biofiltration of airstreams contaminated with MTBE

The treatment of groundwater contaminated with low concentrations of methyl tertiary butyl ether (MTBE) is of nationwide concern. Many treatment techniques include removing MTBE vapors from groundwater, resulting in airstreams that require treatment. One method used for air‐phase MTBE treatment is biofiltration. In a biofilter, the vapors pass through a reactor that contains MTBE‐biodegrading organisms attached to a porous media. This article reports the results of a biofiltration study to treat air contaminated with MTBE at concentrations of 0.2 to 0.33 mg/l, concentrations frequently encountered in the field. The results indicate that MTBE removal at these low concentrations is not as efficient as removals seen at higher concentrations. Activated carbon was shown to be a superior biofiltration medium, compared with media that do not adsorb MTBE vapors. Activated carbon was especially helpful in treatment shock loads of MTBE. © 2002 Wiley Periodicals, Inc.     

Baked Foams Based on Cassava Starch Coated with Polyvinyl Alcohol with a Higher Degree of Hydrolysis

The aims of this work were to produce trays based on cassava starch, coated with polyvinyl alcohol (PVA) with a higher degree of hydrolysis (98%), and to study the effects of the coating on the mechanical and water sorption properties of the trays. Two types of PVA were tested: SELVOL? 325 (degree of polymerization?=?1000–1500) and SELVOL? 107 (degree of polymerization?=?350–650). A decrease in the water absorption capacity of 50% was observed when the coated samples were compared with the control sample after 30 min of immersion in water. It was observed in both coated samples a reduction of the initial rate of water adsorption sorption and a decrease in hydrophilicity compared with the control sample. Tensile strength and elongation were increased with application of the coatings. The use of the two types of PVA resulted in materials with similar mechanical and water sorption properties.     

Remediation of sites contaminated with TCE

Widespread use of trichloroethylene (TCE) in the U.S. has resulted in its frequent detection in soil and groundwater. TCE can become a health hazard after being processed in the human liver; or reductive dehalogenation in the environment may result in production of vinyl chloride, a known carcinogen. This has generated a high degree of interest in efficient and cost-effective technologies that can be used to remediate soil and ground-water contaminated with TCE. The purpose of this paper is to present and discuss relevant physicochemical properties and reactive mechanisms of TCE, and to delineate and discuss promising remediation methodologies that have been proposed and/or demonstrated for restoring contaminated subsurface environments. The information in this article has been funded wholly or in part by the U.S. EPA under contract No. 68–C8–0058 to Dynamac Corporation; it has been subjected to the Agency's peer and administrative review process and approved for publication.     

Soil reinforcement with recycled carpet wastes.

A root or fibre-reinforced soil behaves as a composite material in which fibres of relatively high tensile strength are embedded in a matrix of relatively plastic soil. Shear stresses in the soil mobilize tensile resistance in the fibres, which in turn impart greater strength to the soil. A research project has been undertaken to study the influence of synthetic fibrous materials for improving the strength characteristics of a fine sandy soil. One of the main objectives of the project is to explore the conversion of fibrous carpet waste into a value-added product for soil reinforcement. Drained triaxial tests were conducted on specimens, which were prepared in a cylindrical mould and compacted at their optimum water contents. The main test variables included the aspect ratio and the weight percentage of the fibrous strips. The results clearly show that fibrous inclusions derived from carpet wastes improve the shear strength of silty sands. A model developed to simulate the effect of the fibrous inclusions accurately predicts the influence of strip content, aspect ratio and confining pressure on the shear strength of reinforced sand.     

How to negotiate remediation projects with regulatory agencies

The news that a company has been identified as a potentially responsible party (PRP) at a federal or state Superfund site usually sends a current of fear through the company's management. Even executives with experience in Superfund projects foresee a lengthy, complicated process that involves enormous expenditures and a possible public relations disaster. The author argues, however, that the Superfund process can be managed in a cost-effective way, prevent reactive responses, inaction, and ineffective action, and applying the business acumen that enabled the company to prosper in the first place. This article explores a critical aspect of the remediation process—negotiation of settlements with regulatory agencies (EPA or a state department of environmental protection)—and details the practical steps needed to conduct those negotiations. It also describes common mistakes that can be avoided. For brevity and clarity, it is assumed that the company in question is the only PRP that has received a notice letter from the regulatory agency.     

用钢渣处理含砷废水

对用钢渣处理含硫废水进行了试验，用配水探讨了钢渣投加量，水样，ＰＨ，混合时间等因素对除砷效果的影响，结果表明，钢渣具有较好的除砷效果。     

Phytoremediation experimentation with the herbicide bentazon

An experiment was performed on six species of trees to determine the feasibility of remediating groundwater contaminated with an agricultural herbicide, bentazon, at a site in southern Louisiana. Fate studies on bentazon support that it is translocated to the plant leaves where it is degraded by photolysis to lower-order derivative compounds within short periods of time. Both transpiration observations and dosing tests suggest that the most favorable phreatophyte and tolerant specie of tree to bentazon exposure was the black willow (Salix nigra).     

Methane generation from corncobs treated with xylanolytic consortia

Consortia were developed for the treatment of corncobs for use as a feedstock in a biogas fermentor. The treatment of corncobs with xylanolytic consortia enhanced the production of methane and biogas. All five consortia developed produced the maximum biogas and methane at a 6% loading rate and 20 days hydraulic retention time (HRT). The maximum biogas yield of 0.59m³/kg volatile solids (VS) with a methane content of 62% was produced with the KK-10 consortium. This was apparently due to a maximum hemicellulose degradation of 88%.     

Vacuum pyrolysis of waste tires with basic additives

Granules of waste tires were pyrolyzed under vacuum (3.5-10kPa) conditions, and the effects of temperature and basic additives (Na(2)CO(3), NaOH) on the properties of pyrolysis were thoroughly investigated. It was obvious that with or without basic additives, pyrolysis oil yield increased gradually to a maximum and subsequently decreased with a temperature increase from 450 degrees C to 600 degrees C, irrespective of the addition of basic additives to the reactor. The addition of NaOH facilitated pyrolysis dramatically, as a maximal pyrolysis oil yield of about 48wt% was achieved at 550 degrees C without the addition of basic additives, while a maximal pyrolysis oil yield of about 50wt% was achieved at 480 degrees C by adding 3wt% (w/w, powder/waste tire granules) of NaOH powder. The composition analysis of pyrolytic naphtha (i.b.p. (initial boiling point) approximately 205 degrees C) distilled from pyrolysis oil showed that more dl-limonene was obtained with basic additives and the maximal content of dl-limonene in pyrolysis oil was 12.39wt%, which is a valuable and widely-used fine chemical. However, no improvement in pyrolysis was observed with Na(2)CO(3) addition. Pyrolysis gas was mainly composed of H(2), CO, CH(4), CO(2), C(2)H(4) and C(2)H(6). Pyrolytic char had a surface area comparable to commercial carbon black, but its proportion of ash (above 11.5wt%) was much higher.     

促脱剂协同传统吹脱法处理高氨氮工业废水

在中试吹脱装置上,通过投加低浓度促脱剂协同传统吹脱法处理高氨氮工业废水(氨氮质量浓度2 369～3 600 mg/L)。结果表明:在相同处理条件下,阴离子促脱剂的氨氮去除效果优于阳离子促脱剂,且促脱剂的碳数越高越有利于氨氮的去除;废水处理的最佳工艺条件为废水pH 12.0、废水温度50℃、吹脱时间5 h、促脱剂投加量25 mg/L、气液比600∶1;该条件下,以木质素磺酸钠为促脱剂协同吹脱法处理高氨氮废水,氨氮去除率可达99%以上,高于传统吹脱法20个百分点以上。     

炼钢污泥生产球团的实验技术

通过对瓦斯泥、OG泥、BF-Q灰和SINTER灰的性能分析及对比性实验,对生产的污泥球团进行生球强度、干球强度检测。在满足球团的强度要求下,确定污泥球团的最佳成球条件(成球压力、水分、粘结剂的种类及用量)。     

Upgrading mixed polyolefin waste with magnetic density separation

Polyolefin fractions are often end fractions resulting from the recycling of end-of-life consumer products. Polypropylene (PP) and polyethylene (PE) are present in such fractions as a mixture. For instance, the ratio of PP and PE in car scrap is 70:30 on average. However, the grade of the PP and PE should typically be better than 97% to be reused again as a high quality product. Density separation of the different polyolefins can be a solution. A promising separation technique is the inverse magnetic density separator (IMDS). This paper discusses the potential of shredder residue, one of the possible polyolefin’s waste stream sources for the IMDS, in detail. Experiments with the separation of polyolefins with an IMDS prototype show both high grade and high recovery. The paper concludes with the economic opportunities of the IMDS in the recycling of polyolefins.     

Measurement of odour with focus on sampling techniques

The treatment of waste and many manufacturing processes cause odour emissions. In order to prevent odours, the residents and businesses in the neighbourhood of such plants complain about odour, and it becomes necessary to reduce the emissions. To achieve that, the emissions have to be investigated and evaluated in a representative and reproducible manner. The DIN EN 13725 (2003) [DIN EN 13725. 2003. Luftbeschaffenheit--Bestimmung der Geruchsstoffkonzentration mit dynamischer Olfaktometrie--Air quality--Determination of odour concentration by dynamic olfactometry, Deutsche Fassung EN 13725:2003. Beuth Verlag, Berlin (DE)] provides a European standard for the measurement of odour. Nevertheless, the subject of sampling is not standardised; even though it has a substantial influence on the results of the measurements. In this paper, the odour measurement itself, as well as the different kinds of sampling methods (depending on the specific type of source), will be presented and discussed.     

Landfill gas upgrading with countercurrent water wash

A pilot-scale countercurrent absorption process for upgrading landfill gas to produce vehicle fuel was studied using absorption and desorption units and water as absorbent. The height-to-diameter ratio of the absorption column used was 3:1 instead of the more conventionally used 20:1 ratio, and a higher pressure was used along with a lower water flow rate. The effects of pressure (10-30bar) and water and gas flow-ratios on the upgrading process were studied. Methane content in the product gas increased to near or above 90% with both gas flows (50 and 100l/min) used at over 20bar pressure with 10l/min water flow and at 30bar pressure with 5l/min water flow. Carbon dioxide content with these upgrading parameters ranged from 3.2% to 4.8%. The remaining fraction of the product gas was nitrogen (from 6% to 7%), while hydrogen sulphide was removed to below the detection limit with all of the upgrading parameters used. The methane content of exhaust gas increased with increasing pressure. In conclusion, the pilot-scale gas upgrading process studied here appears to be able to produce gas with high energy content (>90% methane), apparently suitable as vehicle fuel, from landfill gas.     

Noncatalytic liquefaction of tar with low-temperature hydrothermal treatment

Water at hydrothermal and supercritical conditions is considered a promising solvent for the degradation of hazardous waste into harmless compounds. Tar liquefaction experiments were conducted using a batch-type reactor at temperatures between 623 K and 673 K and at pressures between 25 and 40 MPa. A reaction mechanism for tar liquefaction is proposed. Moreover, on the basis of the experimental results, this method could become an efficient method for tar liquefaction, producing high yields of valuable chemical intermediates.     

Mechanochemical dechlorination of polyvinyl chloride with calcium sulfates

Polyvinyl chloride (PVC) was milled with hydrated or unhydrated calcium sulfates (CaSO₄·2H₂O or CaSO₄) in air by using a planetary mill to investigate mechanochemical dechlorination behavior. The milling process resulted in size reduction and in the breaking of bonds leading to mechanically induced solid state reaction, forming CaCl₂ and dechlorinated hydrocarbon with C=C double bonds in the product. Washing the milled mixtures with water at room temperature allowed removal of the chloride formed during milling, and more than 95% of the chlorine in PVC was removed from a mixture milled for 4 h. This process could offer a potential route for the handling and disposal of both PVC and gypsum wastes. H₂S gas was generated during milling; more H₂S was released from the unhydrated sample than from the hydrated sample.     

锌粉对1,2,4-三氯苯的脱氯性能

采用锌粉对1,2,4-三氯苯（1,2,4-TCB）进行了脱氯的研究。实验结果表明,在40mL质量浓度为22.94m g/L的1,2,4-TCB水溶液中加入1.0g锌粉,反应24h时,1,2,4-TCB的还原率可达94.6%;反应16h时,试样中的Cl-浓度约为1,2,4-TCB完全脱氯所得Cl-理论浓度的30%;锌粉还原1,2,4-TCB的反应能在较宽的pH范围内进行,弱碱性条件下的脱氯效果最好,1,2,4-TCB的还原率达70%。