Labour Productivity in Construction Industry in Nigeria: Case of Lagos and Port Harcourt, Southern Nigeria

The problem of labor productivity in construction industry in Nigeria has been an issue of concern to most contractors and professionals.  This paper attempts to identify the factors that affect labor productivity by conducting a survey that relates to these problems encountered at construction sites.  Eighteen (18) problems that could affect construction labor productivity were identified and a qualitative survey was conducted using questionnaires.  One hundred and twenty (120) questionnaires were distributed out of which 104 were returned (87%).  The problems were ranked in their answers in terms of ‘very often’, ‘often’, ‘sometimes’ , ‘rarely’ , or ‘never’.  The analysis of the survey was performed using the importance index.  The values of the importance indices identified the involvement of non professionals, material shortages; variation in cost of materials, recruitment of supervisors, inclement weather, stoppage because of owner/landowners conflict, stoppage because of insolvency of subcontractor/suppliers, labor disruption, delay in material deliveries to site, disruption of power/water supply as the major factors affecting labor output.  The recruitment of workers was identified as of little significance in the studied areas. Keywords: Construction, Labour productivity

Investigative performance of activated anthill clay on the sorption of lead(II) ion from textile wastewater: Characterization, parametric optimization, isotherm, kinetics and thermodynamics studies

The increase in population have had a negative impact on the water quality environment despite the strong polices implemented on the wastewater treatment as the problem remains demanding. However, it is imperative to secure the environment of aquatic and human life. In this study, Anthill clay was activated with H2SO4 to obtain activated Anthill clay (AAC). The adsorbent was analyzed using the state of art techniques. The Brunner emitter teller (BET) surface area of AAC was 228.453 m2/g. The response surface methodology (RSM) was introduced for the optimization of lead (II) ion uptake where the removal efficiency of 92.73% was observed at optimum condition of 35 °C, 0.1g and 10 min respectively. Various adsorption parameter such as pH, temperature, adsorbent dosage and contact time was carried out. The interaction effect between the parameters were investigated. The Jovanovich model and Pseudo second order revealed the adsorption data fitted well for both isotherm and kinetics model. The thermodynamic results showed that the reaction is endothermic, spontaneous, and chemisorption in nature. From the various analysis conducted it can therefore be inferred that anthill clay can be effective and efficient for treatment of harmful substance present in wastewater