Effects of free formaldehyde emission reduction by ammonia fuming on physical and strength properties of particleboards made from formaldehyde based resins

Particleboards made using formaldehyde adhesives cause substantial emission of free formaldehyde over time. Free formaldehyde is harmful to the user’s health and it also weakens internal bonds of particleboards in use. Emissions levels of formaldehyde lie between 0.8 to 2.2 g/m3 of indoor air in particleboards constructed homes. This study was carried out to quantify the amount of free pormaldehyde in particleboards from Raiply Ltd in Eldoret, suggest possible ways to reduce the emissions and determine the effect of the treatment on physical and mechanical  properties of the particleboards. Five samples were selected randomly and, different sections of the boards were prepared and soaked in distilled water for different times. Samples fumed with ammonia at different  durations from 15 to 60 minutes were subsequently soaked for 1 to 24 hours to determine water absorption. High Pressure Gas Chromatography (HPGC) was used to quantify free formaldehyde present in each leachate. Ammonia treated and untreated samples were tested for both physical andmechanical properties at the Kenya Bureau of Standards. The study revealed that fuming particleboards with ammonia reduces the amount of free formaldehydes, on average, by 100%. Ammonia fuming reduces particleboards thickness swelling by between 14.01 and 11.5% and waterabsorption by between 95.6 and 90.5%. the fuming increased MOE of particleboards from 2689.9 to 3405.3 kN/mm and MOR from 10.3 N/mm to 9.3 N/mm. Ammonia fuming should therefore be used to reduce free formaldehyde emission indoor. It’s recommended that further studies becarried out to determine long-term effect of ammonia fumes on particleboards.Key words: Particleboards, ammonia fuming, formaldehyde adhesives and emissio

Five Year Growth and Survival of Eucalyptus Hybrid Clones in Coastal Kenya

Twelve eucalyptus hybrid clones (6 grandis-camaldulensis i.e. GC and 3 grandis-urophylla i.e. GU hybrids) and 3 local landraces (E. camaldulensis, E. tereticornis, and E. urophylla) were established in Gede, Sokoke, and Msambweni in the Coast Province of Kenya in 2002, to compare growth, survival, and adaptability in the 3 sites.  By the end of the 1st year, trees in Sokoke were more than 3 times the mean height of those in Gede and Msambweni. However, these growth advantages during the 1st year in Sokoke were not maintained and by year 2 Gede had caught up, although Msambweni still lagged behind. By age 5 there were significant growth differences between clones. Of the tree sites, Msambweni had the lowest tree growth.  GC167, GC14, GC581, and GC584 proved themselves as the better clones, while E. camaldulensis and E. urophylla were the better local land races. Overall, the “local land races” performed poorly in all sites.  Survivals were over 80% in all sites for the best performing clones. However, in Sokoke, 1 clone died (GU7) while another (GU8) had a survival of less than 20%, while EC and ET had survivals less than 35%. GC796 died in Msambweni and had 8% survival at Gede. The poor survivals in Sokoke may have been due to a severe drought in the 3rd year.  The initial outstanding growth performance in Sokoke may have been due to the fact that Sokoke was a ‘virgin’ forest site and presumably more fertile than the other two sites. These results show that recommendations on outstanding clones or new germplasm for planting or sale to farmers are best done at the end of the rotation for a particular intended product or use

Five Year Growth and Survival of Eucalyptus Hybrid Clones in Coastal Kenya

Twelve eucalyptus hybrid clones (6 grandis-camaldulensis i.e. GC and 3 grandis-urophylla i.e. GU hybrids) and 3 local landraces (E. camaldulensis, E. tereticornis, and E. urophylla) were established in Gede, Sokoke, and Msambweni in the Coast Province of Kenya in 2002, to compare growth, survival, and adaptability in the 3 sites.  By the end of the 1st year, trees in Sokoke were more than 3 times the mean height of those in Gede and Msambweni. However, these growth advantages during the 1st year in Sokoke were not maintained and by year 2 Gede had caught up, although Msambweni still lagged behind. By age 5 there were significant growth differences between clones. Of the tree sites, Msambweni had the lowest tree growth.  GC167, GC14, GC581, and GC584 proved themselves as the better clones, while E. camaldulensis and E. urophylla were the better local land races. Overall, the “local land races” performed poorly in all sites.  Survivals were over 80% in all sites for the best performing clones. However, in Sokoke, 1 clone died (GU7) while another (GU8) had a survival of less than 20%, while EC and ET had survivals less than 35%. GC796 died in Msambweni and had 8% survival at Gede. The poor survivals in Sokoke may have been due to a severe drought in the 3rd year.  The initial outstanding growth performance in Sokoke may have been due to the fact that Sokoke was a ‘virgin’ forest site and presumably more fertile than the other two sites. These results show that recommendations on outstanding clones or new germplasm for planting or sale to farmers are best done at the end of the rotation for a particular intended product or use

Thermogravimetric and reaction kinetic analysis of biomass samples from an energy plantation

The products of a Hungarian experimental plantation for energy crops were investigated. Young shoots of poplar clones (Populus x euramericana and Populus x interamericana), black locust (Robinia pseudoacacia), willow (Salix alba), and an herbaceous plant (Miscanthus sinensis) revealed unexpectedly similar thermal behavior in inert and oxidative atmospheres, as well. An 8-fold difference in the level of grinding did not result in substantial differences in the thermal decomposition. The effect of oxygen in the ambient gas was studied at low sample masses (0.2-0.4 mg) that excluded the overheating due to the high reaction heat of the combustion process. The presence of oxygen affects the decomposition from ca. 220 degreesC. Nevertheless, the extrapolated onset temperature of the hemicellulose decomposition is practically the same at 0, 5, and 21 V/V% oxygen. A group of 12 experiments, representing two grinding levels, three plant genera and four different heating programs were evaluated simultaneously by the method of least squares employing the model of independent pseudocomponents. All evaluated experiments were well described by the same set of kinetic parameters; only the parameters describing the peak area of the partial processes differed. A technique was recommended for the appropriate handling of the nonrandom errors in the simultaneous evaluation of experiment series

The Commercial Profitability of Growing Hybrid Eucalyptus Clones in The Coast Province, Kenya

Due to the current high demand for timber, fuelwood, and building poles and the realization that tree growing may pay dividends in the short and long term, many farmers are planting trees on their farms. Farmers are increasingly planting eucalyptus partly due to the fast growth rates of the hybrid clones as well as the opportunity to earn money within a short time. In this paper we report on the profitability of growing eucalyptus hybrid clones in the coastal region, Kenya. Tree growth and cost data was sourced from farmers in Malindi, Kilifi, and Msambweni. Market information was sourced from hardwares in North and South Coast while tree growth models were used to provide average tree sizes at various ages. Results showed that a farmer could make a net income of upto Kshs.500,000.00 (USD6,250) in 5 years. Farmers in the South Coast (Kwale and Msambweni) spent more on transport than their counterparts in the North Coast (near Gede-KEFRI). This, added to the fact that trees in the South Coast (Msambweni) grew less compared to those in North Coast meant that farmers in the south made less profits

Ojunga(Etiegni)_Impact of a Kraft Pulp and Paper Mill Effl uent on

Phytoplankton and macroinvertebrate assemblages were used to assess the impact of a kraft pulp and paper mill effluent in Kenya, on River Nzoia downstream of the discharge point in relation to changes in water quality during May to June and November 2008 (rainy and dry seasons, respectively). Total phosphorus concentration increased from 0.027 mg·L-1 upstream to 0.04 mg·L-1 downstream. Ammonia nitrogen (NH3-N) concentration was 0.51 mg·L-1 upstream and 0.86 mg·L- 1 downstream. Nitrate concentration stood at 1.18 mg·L-1 upstream compared with the 2.23 mg·L-1 downstream. The pH changed from 4.5 to 5.0 upstream to 5.5 to 6.0 downstream, while DO increased from 6.57 to 7.03 mg·L-1 downstream. The BOD5 (biochemical oxygen demand after five days) values remained almost unchanged from 4.63 mg·L-1 upstream to 4.67 mg·L-1 downstream. Taxon composition of phytoplankton and macroinvertebrates correlated with adverse environmental gradients resulting from the mill’s effluent discharge. Overall, there was a shift in composition and abundance of both phytoplankton and macroinvertebrates, with the downstream site recording high numbers of tolerant taxa (i.e., Microcystis sp. and Chironomus sp.). It was recommended that water quality monitoring with effluents of this nature be done using a combination of chemical analysis and biological indicators such as phytoplankton and macroinvertebrate