Mutagenicity assessment of textile dyes from Sanganer (Rajasthan)

Sanganer town, district Jaipur (Rajasthan, India) is famous worldwide for its hand block dyeing and textile printing industries. These industries use a variety of chemicals and dyes during processing and finishing of raw materials. Most of the textile dyes used by these industries have not been evaluated for their impact on health and the environment. The workers in these industries are exposed to such dyes with no control over the length and frequency of exposure. Further, untreated and sometimes even treated effluents from these industries are released into surface waters of Amani Shah drainage or through the drainage systems, seep into the ground water and adjoining water bodies. Since many textile dyes are known carcinogens and mutagens, a complete evaluation of the safety of these dyes in the human environment must include an evaluation of their genotoxicity or mutagenicity. A total of 12 textile dyes from Sanganer were tested for their mutagenicity, by Ames Salmonella reversion assay using strain TA 100 of Salmonella typhimurium. Only 1 dye, Red 12 B showed absence of mutagenic activity. The remaining 11 dyes were all positively mutagenic.     

Isolation of Thiobacillus sp from aerobic sludge of distillery and dairy effluent treatment plants and its sulfide oxidation activity at different concentrations

In the present study two strains of Thiobacillus sp were isolated from aerobic sludge of distillery and dairy effluent treatment plant using standard methods of isolation and enrichment. Experiments were conducted using isolated cultures in batch bioreactor with initial sulfide concentration of 75 and 150 mg/l. The effect of initial sulfide concentration on the activity of isolated Thiobacillus sp was studied. Sulfide oxidizing capacity was also determined at different initial sulfide concentrations. The results from the study indicate the possible isolation of Thiobacillus cultures from native source and application in the full-scale reactor     

Antihyperglycemic and antihyperlipidemic effects of Tephrosia purpurea leaf extract in streptozotocin induced diabetic rats

Diabetes mellitus is a worldwide leading metabolic syndrome, associated with profound alterations in carbohydrate, lipids, lipoproteins and protein metabolisms. Worldwide, traditional practitioners for the treatment of diabetes and its complications use a wide variety of medicinal plants. In the present study the aqueous extract of Tephrosia purpurea leaves (TpALet) was evaluated for its antihyperglycemic and antihyperlipidemic effects in streptozotocin induced diabetic rats. Profound alterations in the concentrations of blood glucose, lipids and lipoproteins were observed in diabetic rats. Oral administration of TpALet to diabetic rats at a dose of 600 mg/kg body weight significantly reduced the level of blood glucose and increased the level of plasma insulin as well as normalized the lipids and lipoproteins profile. The present study thus demonstrated that TpALet has prominent antihyperglycemic and antihyperlipidemic effects in streptozotocin induced diabetic rats.     

Fluorosis caused by indoor coal combustion in China: discovery and progress

In this study, investigations into endemic fluorosis were conducted and fluorine concentration in environmental samples determined. In an indoor coal-combustion-type fluorosis area, local clay was used to mix with coal for indoor combustion. There are two key steps in the procedure of the indoor transition of fluorine: indoor wet corns and vegetables strongly absorbed fluorine from indoor air; and fluorine strongly accumulated in clay, which was mixed with coal for combustion. Therefore, with the increasing of the percentage of clay in the clay-mixed coal as well as corn in foodstuff, the ratio of fluorosis will be increased.     

Modelling municipal solid waste generation: a review

The objective of this paper is to review previously published models of municipal solid waste generation and to propose an implementation guideline which will provide a compromise between information gain and cost-efficient model development. The 45 modelling approaches identified in a systematic literature review aim at explaining or estimating the present or future waste generation using economic, socio-demographic or management-orientated data. A classification was developed in order to categorise these highly heterogeneous models according to the following criteria--the regional scale, the modelled waste streams, the hypothesised independent variables and the modelling method. A procedural practice guideline was derived from a discussion of the underlying models in order to propose beneficial design options concerning regional sampling (i.e., number and size of observed areas), waste stream definition and investigation, selection of independent variables and model validation procedures. The practical application of the findings was demonstrated with two case studies performed on different regional scales, i.e., on a household and on a city level. The findings of this review are finally summarised in the form of a relevance tree for methodology selection.     

A management system for end-of-life tyres: a Portuguese case study

The European Union introduced several policy instruments based in the extended producer responsibility (EPR) in order to improve the environmental performance of products and services through their life cycles. In this context, the Portuguese government decided to apply the EPR concept to tyres, and producers were obliged to constitute an end-of-life management system to promote the collection, recycling and reuse of end-of-life (EOL) tyres. This required producers, distributors, recyclers and retreaders to be identified and characterized, and local processing infrastructures to be analyzed. The information was used to design an economically optimised EOL tyre management system while promoting the activity of all EOL operators in order for the imposed collecting and recovery targets to be fulfilled. This paper discusses the interaction between the different governmental, private and academic institutions for the creation of the integrated management system for EOL tyres, the approach taken, the technical, political and legal aspects underneath them, as well as the environmental consequences induced by the creation of the management system. The results obtained during the first years of operation are reported and show an increase in the collection and recycling of EOL tyres and the consolidation of the collection and processing infrastructures.     

Reuse of thermosetting plastic waste for lightweight concrete

This paper presents the utilization of thermosetting plastic as an admixture in the mix proportion of lightweight concrete. Since this type of plastic cannot be melted in the recycling process, its waste is expected to be more valuable by using as an admixture for the production of non-structural lightweight concrete. Experimental tests for the variation of mix proportion were carried out to determine the suitable proportion to achieve the required properties of lightweight concrete, which are: low dry density and acceptable compressive strength. The mix design in this research is the proportion of plastic, sand, water-cement ratio, aluminum powder, and lignite fly ash. The experimental results show that the plastic not only leads to a low dry density concrete, but also a low strength. It was found that the ratio of cement, sand, fly ash, and plastic equal to 1.0:0.8:0.3:0.9 is an appropriate mix proportion. The results of compressive strength and dry density are 4.14N/mm(2) and 1395kg/m(3), respectively. This type of concrete meets most of the requirements for non-load-bearing lightweight concrete according to ASTM C129 Type II standard.     

Variations of metal distribution in sewage sludge composting

In the study, the variations of heavy metal distributions (of Cu, Mn, Pb, and Zn) during the sewage sludge composting process were investigated by sequential extraction procedures. The total content of Cu and Zn in the composted mixture increased after the composting process. Mn and Zn were mainly found in mobile fractions (exchangeable fraction (F1), carbonate fraction (F2), and Fe/Mn oxide fraction (F3)). Cu and Pb were strongly associated with the stable fractions (organic matter/sulfides fraction (F4) and residual fraction (F5)). These five metal fractions were used to calculate the metal mobility (bioavailability) in the sewage sludge and composted mixture. The mobility (bioavailability) of Mn, Pb, and Zn (but not Cu) increased during the composting process. The metal mobility in the composted mixture ranked in the following order: Mn>Zn>Pb>Cu.     

Biodegradability of biodegradable/degradable plastic materials under aerobic and anaerobic conditions

A study was conducted on two types of plastic materials, Mater-Bi Novamont (MB) and Environmental Product Inc. (EPI), to assess their biodegradability under aerobic and anaerobic conditions. For aerobic conditions, organic fractions of municipal solid wastes were composted. For the anaerobic process, anaerobic inoculum from a wastewater treatment plant was used. Cellulose filter papers (CFP) were used as a positive control for both mediums. The composting process was monitored in terms of temperature, moisture and volatile solids and the biodegradation of the samples were monitored in terms of mass loss. Monitoring results showed a biodegradation of 27.1% on a dry basis for MB plastic within a period of 72 days of composting. Biodegradability under an anaerobic environment was monitored in terms of biogas production. A cumulative methane gas production of 245ml was obtained for MB, which showed good degradation as compared to CFP (246.8ml). However, EPI plastic showed a cumulative methane value of 7.6ml for a period of 32 days, which was close to the blank (4.0ml). The EPI plastic did not biodegrade under either condition. The cumulative carbon dioxide evolution after 32 days was as follows: CFP 4.406cm(3), MB 2.198cm(3) and EPI 1.328cm(3). The cumulative level of CO(2) varying with time fitted sigmoid type curves with R(2) values of 0.996, 0.996 and 0.995 for CFP, MB and EPI, respectively.     

Sorption of the veterinary antimicrobials sulfadimethoxine and ormetoprim in soil

Currently, limited research on the fate of antimicrobials in the environment exists, once they are discharged in human and animal wastes. Sorption of two antimicrobials, sulfadimethoxine (SDM) and ormetoprim (OMP), was investigated in two soils and sand using a series of batch experiments. Because OMP and SDM are often administered in combination, their sorption was also investigated in combination as co-solutes. The rate of SDM and OMP sorption was rapid over the first few hours of the experiments, which then slowed considerably after 16 to 68 h. OMP sorption was enhanced at high concentrations when in combination with SDM, with linear sorption coefficients ranging from 1.3 to 58.3 L.kg(-1) in the single solute experiments and 4.96 to 89.7 L.kg(-1) in the co-solute experiments. Sorption of OMP as a single solute seems to provide a better fit with the Freundlich equation, which became more linear (n approached 1) when SDM was present. Overall, SDM sorbed less than OMP in the two soils and sand. SDM linear sorption coefficients ranged from 0.4 to 25.8 L.kg(-1) as a single solute and 2.5 to 22.1 L.kg(-1) as a co-solute. Sorption of SDM becomes more nonlinear (n < 1) when SDM is present in combination with OMP. Overall, sorption of both antimicrobials increased in the selected soils and sand as the organic matter, clay content, and cation exchange capacity increased. These experiments indicate relatively low sorption of SDM and OMP in natural soils, making them a potential threat to surface and ground water.