Evaluation of biogas upgrading technologies and future perspectives: a review

Environmental Science and Pollution Research - Biogas is acknowledged as one of the foremost bioenergy to address the current environmental and energy challenges being faced by the world. Commonly,...     

Adsorption characteristics of Cu and Ni on Irish peat moss

Peat has been widely used as a low cost adsorbent to remove a variety of materials including organic compounds and heavy metals from water. Various functional groups in lignin allow such compounds to bind on active sites of peat. The adsorption of Cu(2+) and Ni(2+) from aqueous solutions on Irish peat moss was studied both as a pure ion and from their binary mixtures under both equilibrium and dynamic conditions in the concentration range of 5-100mg/L. The pH of the solutions containing either Cu(2+) or Ni(2+) was varied over a range of 2-8. The adsorption of Cu(2+) and Ni(+2) on peat was found to be pH dependent. The adsorption data could be fitted to a two-site Langmuir adsorption isotherm and the maximum adsorption capacity of peat was determined to be 17.6 mg/g for Cu(2+) and 14.5mg/g for Ni(2+) at 298 K when the initial concentration for both Cu(2+) and Ni(2+) was 100mg/L, and the pH of the solution was 4.0 and 4.5, respectively. Column studies were conducted to generate breakthrough data for both pure component and binary mixtures of copper and nickel. Desorption experiments showed that 2mM EDTA solution could be used to remove all of the adsorbed copper and nickel from the bed.     

A comparative assessment of the impact of different occupations on workers' static musculoskeletal fitness.

An ergonomic assessment of the involvement of static muscular forces like back strength, grip strength and pinch strength in different occupations was made. A study was conducted on 45 normal adult males (15 subjects per group) which included video display terminal (VDT) operators, industrial workers and safety inspectors. Their maximum back strength, handgrip strength and pinch strength were measured with dynamometers. The observed values of back strength were significantly lower in VDT operators while significantly higher in safety inspectors and moderate in industrial workers. The values of grip strength and pinch strength of all sample groups were more or less similar. The findings clearly indicate that static muscular strength varies significantly in different occupations. Heavy static muscular load might lead to an accumulation of metabolic waste and toxins on the back resulting in lower back strength in VDT operators and industrial workers.     

Modeling the energy content of combustible ship-scrapping waste at Alang-Sosiya, India, using multiple regression analysis

Alang-Sosiya is the largest ship-scrapping yard in the world, established in 1982. Every year an average of 171 ships having a mean weight of 2.10 x 10(6)(+/-7.82 x 10(5)) of light dead weight tonnage (LDT) being scrapped. Apart from scrapped metals, this yard generates a massive amount of combustible solid waste in the form of waste wood, plastic, insulation material, paper, glass wool, thermocol pieces (polyurethane foam material), sponge, oiled rope, cotton waste, rubber, etc. In this study multiple regression analysis was used to develop predictive models for energy content of combustible ship-scrapping solid wastes. The scope of work comprised qualitative and quantitative estimation of solid waste samples and performing a sequential selection procedure for isolating variables. Three regression models were developed to correlate the energy content (net calorific values (LHV)) with variables derived from material composition, proximate and ultimate analyses. The performance of these models for this particular waste complies well with the equations developed by other researchers (Dulong, Steuer, Scheurer-Kestner and Bento's) for estimating energy content of municipal solid waste.     

Oxygen uptake in relation to group size in the juveniles of a climbing perch, Anabas testudineus (Bloch)

The present work reports oxygen uptake in relation to group size in the juveniles (body weight: 0.70 to 1.30 g) of a climbing perch, Anabas testudineus (Bloch). The experiments were conducted at 21.5 +/- 1.0 degrees C using a cylindrical glass respirometer having continuous water flow system. With an increase in the number of fish at an interval of 5 from 5 to 40 in each fourth subsequent experiment, the weight specific aquatic oxygen uptake of a fish decreased from 0.192 +/- 0.030 to 0.800 +/- 0.006 ml O2 x g(-1)x(h(-1). When compared with a controlled fish, there was a reduction of 27.80% in the oxygen uptake in a group of 5 but 58.39% in a group of 40. A negative and significant correlation (r = 0.8411, p < 0.01) was calculated between oxygen uptake and group size of fishes. The investigation showed that probably due to shoaling behaviour, the aquatic oxygen uptake in the juveniles of A. testudineus always remained high in controlled fish or a fish in isolation than when they were in a group.