Polyalkylphenyl-sulphonic acids with acid groups of variable strength from animal-vegetable wastes

The insoluble organic fraction isolated from rice-hulls residues and animal fecal matter mixture is sulphonated in liquid SO3 at 200 degrees C to a water soluble sulphonate (III). III is compared to the sulphonate (IV) obtained from the same mix after composting. Both products have been found to contain mixtures of molecules with close molecular weight. These molecules consist of a central cicloaliphatic cluster with peripheral pending aromatic chains. III and IV appear to have the same sulphonation degree. However, the latter contains higher concentrations of cicloaliphatic fragments and of amide, phenol and ether bonds, but less carboxylic and amine functional groups. These differences may be reasonably traced back to the starting materials. By comparison with commercial lignosulphonates derived from the paper and pulp industry, the above arylsulphonates are likely candidates for a variety of applications in the chemical industry and in agriculture. We conclude that sulphonation, even under the drastic experimental conditions of this work, does not seem to erase the memory of the parent matter structure. This reaction is capable of upgrading recalcitrant organic matter in vegetable waste residues to an interesting variety of lignosulphonates.     

An IR study to investigate the structural relationship of lignin-like matter and lignosulphonates obtained from animal-vegetable wastes

Lignin-like matter (I) from rice hull residues and humin-like matter and (II) from rice hull-fecal matter compost yield, upon sulphonation by SO(3), the lignosulphonates III and IV, respectively. The solid state IR spectra of I and II are analysed and interpreted based on the functional groups content values obtained for III and IV by solution NMR spectroscopy. IR absorbance values at five selected wavelengths for I and II correlate well with functional groups content values for III and IV according to Beer's law. It is concluded that the sulphonated derivatives, aside from the -SO(3)H content, reflect well the chemical structure of the parent materials. No side reaction of I or II with SO(3), other than C sulphonation, is apparent. The above correlation may be useful for waste management purposes.     

The challenge of remediation technology development

A huge commercial environmental industry, currently estimated at some $130 billion in size in the United States alone, has sprung up to manage and remediate environmental problems. Hundreds of innovative remediation technologies are being developed under EPA's SITE program, which has provided R&D funding for more than 100 new treatment technologies. Despite the obvious demand, numerous regulatory, marketing, technical, and financial barriers have impeded progress in the field of remediation technology development. Developers of remediation technologies are faced with a significant challenge to overcome these barriers and successfully bring a technology to market. This article examines the barriers to technology development and offers strategic planning alternatives for long-term economic success and commercial viability of remediation technologies.     

The Market for Waste Vitrification Technology

Waste vitrification technology has largely been developed by the United States Department of Energy (DOE). Numerous vendors offer vitrification units, and a number of commercial and large pilot applications have been made. Nevertheless, the industry is still in its infancy and does not dominate any waste treatment niche. DOE funding of vitrification technology development is nearing an end, and DOE waste treatment is being privatized, with private bidders selecting the technologies and offering to treat wastes for a per-unit fee. Thus, the DOE market is shifting from a cost-plus, largely R&D environment to a fixed-fee environment in which vendors and waste treatment contractors must accept technological risks. Significant quantities of DOE waste are still uncommitted, but the number of vendors is larger than the market can possibly sustain. Domestic private sector opportunities are limited and vendors are looking to foreign markets with less mature treatment capacity and growing demand.     

Vitrification as an alternative to landfilling of tannery sewage sludge

Due to high content of heavy metals such as chromium, tannery sewage sludge is a material which is difficult to be biologically treated as it is in the case of organic waste. Consequently, a common practice in managing tannery sewage sludge is landfilling. This poses a potential threat to both soil and water environments and it additionally generates costs of construction of landfills that meet specific environment protection requirements. Vitrification of this kind of sewage sludge with the addition of mineral wastes can represent an alternative to landfilling.The aim of this study was to investigate the possibility of obtaining an environmentally safe product by means of vitrification of tannery sewage sludge from a flotation wastewater treatment process and chemical precipitation in order to address the upcoming issue of dealing with sewage sludge from the tannery industry which will be prohibited to be landfilled in Poland after 2016. The focus was set on determining mixtures of tannery sewage sludge with additives which would result in the lowest possible heavy metal leaching levels and highest hardness rating of the products obtained from their vitrification.The plasma vitrification process was carried out for mixtures with various amounts of additives depending on the type of sewage sludge used. Only the materials of waste character were used as additives.One finding of the study was an optimum content of mineral additives in vitrified mixture of 30% v/v waste molding sands with 20% v/v carbonate flotation waste from the zinc and lead industry for the formulations with flotation sewage sludge, and 45% v/v and 5% v/v, respectively, for precipitation sewage sludge. These combinations allowed for obtaining products with negligible heavy metal leaching levels and hardness similar to commercial glass, which suggests they could be potentially used as construction aggregate substitutes. Incineration of sewage sludge before the vitrification process lead to increased hardness of the vitrificates and reduced leaching of some heavy metals.     

Recovery of coagulant from water supply plant sludge and its effect on clarification

Spent coagulant in water supply plant sludge was extracted with H₂SO₄ and the efficiency of the reused coagulant was studied. The optimum pH values for coagulant extraction and clarification with the reused coagulant were 3.0–4.0 and about 6, respectively. In treating raw influent obtained from a sewage treatment plant and wastewater from a coastal landfill site, the removal of chemical oxygen demand (COD), total nitrogen, and total phosphorous with the recovered coagulant was higher than that with commercial aluminum sulfate or polyaluminum chloride. In addition, the sludge settling properties, the extra sludge mass formation, the supernatant quality, and the cost of reagents were also studied. The coagulant recovered from water supply plant sludge by H₂SO₄ extraction could be successfully reused for the clarification of domestic and food industry wastewaters.     

Recycling carbon fibre reinforced polymers for structural applications: technology review and market outlook

Both environmental and economic factors have driven the development of recycling routes for the increasing amount of carbon fibre reinforced polymer (CFRP) waste generated. This paper presents a review of the current status and outlook of CFRP recycling operations, focusing on state-of-the-art fibre reclamation and re-manufacturing processes, and on the commercialisation and potential applications of recycled products. It is shown that several recycling and re-manufacturing processes are reaching a mature stage, with implementations at commercial scales in operation, production of recycled CFRPs having competitive structural performances, and demonstrator components having been manufactured. The major challenges for the sound establishment of a CFRP recycling industry and the development of markets for the recyclates are summarised; the potential for introducing recycled CFRPs in structural components is discussed, and likely promising applications are investigated.     

Perceived values of benefits from Mississippi's forestry Best Management Practices

Numerous studies in the United States have shown that, in addition to accomplishing their primary objective of preventing or reducing non-point source (NPS) pollution, silvicultural Best Management Practices (BMPs) provide additional direct and indirect benefits. These benefits are valuable to a host of forestry-related groups because they improve forest habitat, improve the public's perception of the timber industry, and increase the overall value of the timber asset. In an effort to gauge the perceived value that forestry-related groups place on BMPs, Mississippi non-industrial private forest (NIPF) landowners (n=63), forestry consultants (n=30), and timber industry professionals (n=8) were surveyed using a combination of in-person, telephone interviews, and mail surveys in spring 2001. Each group was asked to rank 35 potential benefits from 1 to 5 (1 being least beneficial; 5 being most beneficial) according to their perceived value of the benefit. Results showed little variation in the overall mean response for all benefits among groups. In general, all groups assigned a ranking of average, more beneficial, or most beneficial to 31 of 35 (88%) potential benefits. Results indicated that, although these groups may have differing perceptions of the value of some benefits, all have a largely positive perception of the potential benefits from BMPs.     

Poly(lactic acid)/Cellulose Composites Obtained from Modified Cotton Fibers by Successive Acid Hydrolysis

This work is focused on the hydrolysis of cotton fibers from waste textiles to obtain micro and nanofibers to be used as reinforcements in polymer composites. To promote their compatibility with polymeric matrix, hydrolyzed cotton fibers were surface modified with various silane compounds. Thus, these fibers were mixed with commercial poly(lactic acid) (PLA) at 5% w/w loading by melt compounding. Acid treatments caused a decrease of the crystallinity index whereas the thermal stability was significantly improved, especially for cellulose fibers hydrolyzed in two steps. Morphological analysis revealed a reduction of the fibers diameter and a decrease of their length as a consequence of the hydrolysis. NMR analysis confirmed the silanization of the fibers by reaction with the silane agent. Tensile tests revealed that silanization treatments were able to increase the composite Young’s modulus and the stress at break with respect to the neat matrix, indicating that silanization improved the polymer/fiber compatibility interfacial adhesion. The overall results demonstrated that applying suitable surface modification strategies, waste cotton textiles can be effectively recycled as fillers in polymer based composites.     

Survey of solid waste generation and composition in a rapidly growing urban area in Central Nigeria

The objective of this study was to carry out a field survey of the solid waste generation profile in parts of Makurdi, a rapidly growing urban city in north central Nigeria. The areas surveyed covered low, medium and high-density residential quarters, representing high/medium/low income groups in the area. Results of the survey show that the bulk ( approximately 82%) of the solid waste generated in the area originates from households, rather than from commercial, institutional or industrial premises. Of the waste from households, a substantial proportion consists of various putrescible materials (36-57%), with ash, dust and sand (combined) forming another significant proportion (21-41%). From the non-household sources, putrescible matter is also significant (23-45%), as is the combined ash/dust/sand fraction (32-36%). The quantity of plastics/cellophane materials from household and non-household sources was, however, comparable (6-10%). There was more paper from commercial and institutional premises (9-12%) than from household or small/medium scale industrial premises (2-4%). Glass (0.1-6.9%), metals (mostly cans and bottle corks, 0.7-3.4%) and textiles (0.3-6%) form only a minor proportion of the waste across generators. Waste generation rates were for households, 0.54kg/cap/day; for commercial, 0.018kg/m(2)/day; institutional, 0.015kg/m(2)/day while for small and medium scale industries, the rate was 0.47kg/m(2)/day. As there is no previous study of this kind in the Makurdi urban area, what is reported here may be taken as baseline for the entire area. The implications of the findings for solid waste management planning are discussed.     

Composting of a solid olive-mill by-product ("alperujo") and the potential of the resulting compost for cultivating pepper under commercial conditions

A pollutant solid material called "alperujo" (AL), which is the main by-product from the Spanish olive oil industry, was composted with a cotton waste as bulking agent, and the compost obtained (ALC) was compared with a cattle manure (CM) and a sewage sludge compost (SSC) for use as organic amendment on a calcareous soil. The experiment was conducted with a commercial pepper crop in a greenhouse using fertigation. Composting AL involved a relatively low level of organic matter biodegradation, an increase in pH and clear decreases in the C/N and the fat, water-soluble organic carbon and phenol contents. The resulting compost, which was rich in organic matter and free of phytotoxicity, had a high potassium and organic nitrogen content but was low in phosphorus and micronutrients. The marketable yields of pepper obtained with all three organic amendments were similar, thus confirming the composting performance of the raw AL. When CM and SSC were used for soil amendment, the soil organic matter content was significantly reduced after cultivation, while it remained almost unchanged in the ALC-amended plots.     

Improving the two-step remediation process for CCA-treated wood: Part I. Evaluating oxalic acid extraction

In this study, three possible improvements to a remediation process for chromated-copper-arsenate- (CCA) treated wood were evaluated. The process involves two steps: oxalic acid extraction of wood fiber followed by bacterial culture with Bacillus licheniformis CC01. The three potential improvements to the oxalic acid extraction step were (1) reusing oxalic acid for multiple extractions, (2) varying the ratio of oxalic acid to wood, and (3) using a noncommercial source of oxalic acid such as Aspergillus niger, which produces oxalic acid as a metabolic byproduct. Reusing oxalic acid for multiple extractions removed significant amounts of copper, chromium, and arsenic. Increasing the ratio of wood to acid caused a steady decline in metal removal. Aspergillus niger removed moderate amounts of copper, chromium, and arsenic from CCA-treated wood. Although A. niger was effective, culture medium costs are likely to offset any benefits. Repeated extraction with commercial oxalic acid appears to be the most cost-effective method tested for the two-step process.     

Production of artificial aggregates by granulation and carbonation of recycled concrete fines

There is a growing need to find ways to reuse fine concrete waste from the construction industry. In this study, recycled concrete fines were granulated and used as lightweight aggregates. Ladle slag, a steel industry residue, was used as a co-binder in different ratios (0, 10, 20, and 30%). The materials were blended and granulated, and then the granules were cured in three conditions: ambient condition, humidity chamber, and carbonation chamber. The results showed that the ladle slag content of 30% cured in a humidity chamber produced the strongest granules, with a crushing strength of 127 N, which was 135% greater than a commercial lightweight aggregate. The granules generally had satisfactory density and water absorption with a higher ladle slag content. Carbonation increased the granule strength with a low ladle slag content and decreased the granules’ water absorption. The improved physical and mechanical properties of carbonated granules are attributed to the formation of calcium carbonate during the carbonation process. The granules produced in this study show good potential for use as lightweight aggregates in the construction industry.

Graphical abstract

     

Converting Waste Polystyrene into Adsorbent: Potential Use in the Removal of Lead and Cadmium Ions from Aqueous Solution

Waste of polystyrene was converted into a cation exchange resin and was used for the removal of lead and cadmium metals from aqueous solution. Wastes consisting of coffee cups were crushed into small pieces and immersed into a solution of sulfuric acid in order to attach sulfonic group to polymer chain, these groups are responsible for the exchange properties of the modified plastic. The cation exchange capacity (CEC) was determined and was comparable to commercial exchangers. The adsorption isotherms of resin with synthetic wastewater containing lead and cadmium ions were tested. Adsorption analysis results obtained at various concentrations showed that the adsorption pattern on the resin followed Langmuir isotherms.     

Enzyme-Mediated Reactions of Oligosaccharides and Polysaccharides

Two types of enzymatic reactions are given here as examples of synthetic problems encountered in industry. In the first case, commercially available -D-galactosidase from Escherichia coli was used as a catalyst to transfer galactose from -lactose to oligosaccharides. A preference for galactosyl transfer to the 3- or 4-position of the sugar moiety of the oligosaccharide was observed for the products. As expected, only the -anomer was produced. A wide variety of sugars, including disaccharides, trisaccharides, cellotetraose, and maltodextrins, has been shown to act as acceptors, yielding oligosaccharides. In the second example, -galactomannan that had been previously treated to contain cationic groups (cationic guar gum) was subjected to treatment with a series of inexpensive commercial enzymes such as lipases, protease, and cellulases. Some enzyme preparations showed significant changes in the viscosities of 1% cationic guar solution. For example, lipases from Aspergillus niger and Aspergillus saitoi and protease XIII from Rhizopus niveus produced a substantial viscosity reduction (0–20% of original viscosity). These examples demonstrate the utility of low-cost enzymes in manipulating polymer structures.     

A Forecast Model Of Refuse Tonnage With Recapture And Uncertainty Bounds

A spreadsheet model for forecasting solid waste tonnages is described. The model uses generation coefficients from the technical literature associated with individual material components (paper, glass, metals, plastics and rubber, organic materials, construction waste, inerts and other) to express the amount of waste produced per capita and per employee in the labor force. Estimates of quantities being generated by two major groups, namely domestic and industrial/commercial/institutional sources are reflected in the model's output. Using this disaggregated format, the model estimates total waste, recaptured waste (as a result of policy initiatives), and net refuse. Confidence intervals are developed using a regression model related to the business cycle. Two worked examples are given for data obtained in Canada.     

Recovery elemental sulfur from calcium sulfide prepared by red gypsum in sulfuric acid wastewater treatment

Journal of Material Cycles and Waste Management - Red gypsum comes from TiO2 production industry by sulfate method, which comes from the low acidic liquid stream treatment using lime or limestone....     

Leaching of heavy metals in acid mine drainage.

Acid mine drainage is one of the most serious environmental problems that the coal and metal mining industry is currently facing. The generation of low pH drainage enhances the dissolution of heavy metals in water. The samples used in this research originated from three pits at mine dumps. In a study reported in this paper, three types of tests; namely static test, kinetic test and column test were conducted to estimate acid generation and acid neutralization reaction rates, and to predict the solubility of metals and their release rates. Static test showed that all samples had a pH of net acid generation (NAG pH) <4, a net acid producing potential (NAPP) >10 kg H2SO4tonne(-1), and a S-content >3%, which can be classified as a high acid-forming capacity. Simulated runoff in the column tests was equivalent to 5-year average rainfall in Indonesia, the resultant leachates showed acidic behaviour (pH < 3.5). Based on the results, it was found that high mobilization of heavy metals (Cr, Cu, Zn, Cd and Pb) takes place under strong acidic conditions (pH approximately equal 2).     

Toxicity screening of biodegradable polymers. II. Evaluation of cell culture test with medium extract

Cell culture testing with material extracts was applied to toxicity screening of some commercial degradable plastics: a plasticized cellulose acetate, an aliphatic polyester (Bionolle), polyhydroxybutyrate-co-hydroxyvalerate (Biopol), and polycaprolactone (TONE polymer). Cell culture medium with serum was used as extraction medium. Methods for the determination of morphology and viability of cells cultured in the extract were investigated. Phase-contrast light microscopy of cells, enhanced by neutral red staining, provides high-contrast images for qualitative evaluation of cell morphology and lysis. Compared to the determination of protein using the Bradford method and of neutral red uptake, the determination of dehydrogenase activity using 3-[4,5-dimethylthia-zol-2-yl]-2,5-diephenyl-tetrazolium bromide (MTT) is more sensitive and accurate. The relative MTT activity of cells cultured in fresh extracts indicate that TONE polymer (all shapes) and Bionolle (test bars and films) are comparable to materials currently used in the food industry (polyethylene terephthalate, atactic and isotactic polystyrene) with no toxic effects on cells.     

Reuse of spent bleaching earth by polymerisation of residual organics

Spent bleaching earth (SBE) is a waste generated by the edible oil industry that currently has limited options for beneficial reuse. In excess of ～2 million tonnes per year of SBE is generated world-wide with major quantities available in the middle-east where significant volumes of edible oils are produced. Low pressure compaction followed by heat treatment at 150 °C causes polymerisation of the residual organic components in SBE and this produces monolithic samples with high unconfined compressive strengths (54 MPa). SBE can therefore be used to manufacture novel clay blocks for use in construction that are bonded by polymerised vegetable oil. This represents a new, innovative and resource efficient application for SBE. In this research, commercial SBE has been characterised and the effects of key processing variables (temperature and compaction pressure) on the compressive strength, porosity and density of the SBE clay blocks are reported and the mechanisms responsible for strength development are discussed.