ABSTRACT

 This study presents the findings of a fieldwork conducted to determine the amount of wood waste generated from sawmills, and an appraisal of the wood waste management technique in Oke-Baba, Lagos located at latitude 6° 291 10llN5 and longitude 5° 391 18"E and Sapele located latitude 5°54i45“N and longitude 5° Nigeria. The two sawmills were studied for volume of wood waste generation during conversion in Oke-Baba, Lagos and Sapele, Delta State. For thirteen months August 2008 to August 2009, data on wood waste generation and post-impact effect on the bio-physical environment ofthe sampled sawmills location for five effective working days per week were collected. The volumes of all the round logs to be converted were determined using absolute form factor formula; specific sampled pairs were compared using t-test. After conversion, the volumes of all lumbers converted were determined and were subtracted from those obtained in the morning, whatever was obtained was the volumes of wood wastes generated in each of the sampled sawmills. This study revealed that: Total solid waste (TSW) ranged from 22.5 to 65.5%. In logs that ① have high form factor (ii) are straight and (iii) are sound, TSW decreased as log volume increased; the value of r2 is 60.0%. Results showed that out of a total waste of 40.0%, bark volume contributed 3.7%, sawdust 12.2%, while the remaining components contributed 24.0%. For the bio-physical environmental impact case study, Noise level showed high values of above 90dB(A) over an 8 hour period using a dosimeter to measure maximum and minimum noise level at the centre of each work area and movement out from 500 - 1 OOOmeters apart. The water quality variables and F value for ANOVA were, conductivity 89.91, BOD5 67.99 nitrate-nitrogen 114.26, phosphate-phosphorus 180.50 and transparency 11.76 which were significantly different (P<0.05) among the stations. ANOVA showed that, station 2(the impacted site) was the cause of the difference in Sapele, The data analysis for air quality using air pump via a mobile laboratory with dylos air quality monitor and exposure limits stationed 500m away from point source with dynamic sensors measured nitric oxide (NO), ammonia (NH3), methane (CH4), hydrogen sulphide (H2S), nitrogen dioxide (NO2), total nitrogen oxide (NOX), sulphur dioxide (SO2), particulate matter (PM10) and ozone (O3) recorded at Lagos urban, and Sapele showed higher volume concentration in Lagos compared to Sapele with t = 4.471. Based on these findings, there is need for educational awareness for the empowerment of the citizens to achieve a healthy and sustainable environment. The underutilization ofthe sawmill waste has resulted in high pollution of the Ebute- Metta environment and aesthetic insult compared to the Sapele environment. It is suggested that the enormous volumes of wood waste generated in virtually all the sawmills in Nigeria (approximately 2000t in all) be collected together at some designated central points throughout Nigeria, converted into briquettes and carbonized into charcoal, be burnt in some specially designed electricity generation plants or conversion through the Torrefaction and Pelletization Process (TOP) to torrefied pellets pooled together, formed into briquettes and carbonized into charcoal. This has a higher heat value than that of wood itself.