Current Research in Landfills
Pathogenic Microbes from Unprotected Landfills Pose Health Hazards with Potentials of Disease Outbreaks in Nigeria
Aims: This study assessed some health hazards associated with landfills and waste dumping by comparing pathogenic microbes from Olusosun Landfill and a control field in Lagos, Nigeria.
Study Design: A comparative, investigative survey.
Place and Duration of Study: Biotechnology Laboratory, Federal Institute of Industrial Research, Oshodi, Lagos, between August 2015 and February 2016.
Methodology: Soil samples were collected from the superficial layers (1-20 cm) of alfisol at the landfill and a field located about 1000 meters from the dumpsite. Coliform counts, identification of bacteria and susceptibility to antibiotics were carried out. One-way Analysis of variance (ANOVA) was used for statistical analysis, with level of significance at 0.05.
Results: Coliform counts were 51×105 and 38 ×105 CFU g-1 dry soil for landfill soil and field soils respectively. Species of Gram-negative bacteria (16) and Gram-positive bacteria (20) found in landfill soil outnumbered Gram-negative bacteria (7) and Gram-positive bacteria (10) found in field soil. potential pathogenic species isolated from landfill soil were Enterobacter, Escherichia coli, Klebsiella, Pseudomonas aeruginosa, Clostridium, Corynebacterium, Micrococcus, and Staphylococcus, outnumbering pathogenic species in field soil. 56.3% of Gram-negative bacteria and 55.0% of Gram-positive bacteria from landfill soil gave Multiple Antibiotic Resistance (MAR) Index above 0.5. Significant differences (P < 0.05) existed between the MAR Index of Gram-negative bacteria in landfill and field soils, but no significant differences (P = 0.6348) between Gram-positive bacteria in landfill and field soils.
Conclusion: The findings reveal that pathogenic species of bacteria inhabiting landfill soil are more diverse and numerous than in field soil. The presence of coliforms in landfill soil is an indication of faecal contamination. This implies that the presence of landfills, though needful, poses health hazards which cannot be overlooked. The author emphasises the importance of sterilizing waste before dumping, citing landfills far from residential areas, water bodies and farms, as well as provision of potable water.
Soil Contamination from Non-sanitary Waste Landfill in Langat Water Catchment Area, Malaysia
Soil is a complex matrix and a major reservoir of contamination. It has the ability to bind many potential toxic elements such as heavy metals and they can exist in various forms. Leachate triggered soil contamination in waste landfill through sorption and migration process. This study determined heavy metals contamination in the soil of non-sanitary landfills in Langat river water catchment area in Selangor. Topsoil samples were collected from four landfill sites and three non-landfill sites for comparison. Soil type, soil pH, organic matter and exchangeable cations were determined using specified method. Available heavy metals in soil samples were determined using Ethylenediaminetetraacetic acid (EDTA). The distribution of heavy metals across landfill sites were performed using ArcGIS. Statistical Package for the Social Sciences (SPSS) statistical software was used to analyse the finding. The overall findings have indicated that Al (2340±575 mg/kg), Fe (2110±330 mg/kg), Cu (65.1±29.6 mg/kg) and Cd (4.99±1.3 mg/kg) were very high in the agriculture soil. Al and Fe also were high in the residential area soils with the mean ± SD of 2760±128 mg/kg and 1620±710 mg/kg respectively. Other elements such as Mn, Zn and Pb were highly detected in waste landfills. The highest Mn and Zn were detected in landfill site B with the mean ± SD of 76.5±13.9 mg/kg and 17.8±24.0 mg/kg respectively. High concentration of Pb was detected in landfill site D (37.9±37.8 mg/kg) and site B (37.5±24.3 mg/kg) while Cd was high in landfill site A (4.61±0.6 mg/kg) and site D (4.39±1.0 mg/kg). Ni was commonly detected as low in all sites. The highest Ni concentration was determined in landfill site B (1.55±3.06 mg/kg). In conclusion, all heavy metals in the studied soils were within the soil standard except for Cd and Cu. Most of heavy metals were retained at the boundary of the landfills. The mobility of heavy metals in the soil was possibly associated with the acidic-pH soils environment, high organic matter and clay content. In conclusion, the soil contamination occurred in both landfills and non-landfill sites where Cu contamination was found in agriculture soil, residential area and landfill site A while Cd contamination was present in all study sites.
Investigating a Southern Manchester Landfill Leachate
The leachate was analyzed for physicochemical parameters and Total Organic Carbon (TOC). The pH and electrical conductivity (EC) levels were determined using pH meter and EC meter respectively, whilst TOC analyzer and Palintest Photometer were used to collect TOC and Ammonia (NH3) concentrations respectively. The results were evaluated in relation to soil standards recommended for soil remediation.The physicochemical characteristic of the leachate from the landfill suggests that they were more acidic (average pH = 6.86) in nature, with EC range of 540 to 1420 µS/cmwhile the TOC values were far above the regulated limit. High NH3 concentration values of up to 2.42 mg/L attests to the humic nature of this Landfill.The high concentration of colour observed could be due to the presence of organic substances. More landfill leachate parameters need to be monitored if a holistic analysis of this particular landfill leachate must be ensured.
LANDFILL SITE SELECTION IN DELTA STATE NIGERIA
Solid waste management is considered as one of the most serious environmental problems confronting municipal authorities in developing countries. With rising urbanization pressurizing land availability for waste disposal; landfills are now sited in unsuitable areas especially in developing countries like Nigeria. This work reviews the literature on landfill siting techniques and brings to the fore the need for proper landfill site selection taking into cognisance significant amount of spatial information, engineering data, environmental, social and economic criteria to locate sites which protects the public and the environment in Delta State.
ENERGY- AND RESOURCE SAVING TECHNOLOGIES OF BUILDING MATERIALS PRODUCTION USING SOLAR ENERGY
The article deals with the production of building materials as an important sector of the country’s economy. This sector of the economy is characterized by a high level of material intensity. The problem of finding new sources of energy is the most important thing in the world. The article considers several methods of using solar energy for heat treatment of various types of concrete: heat treatment of conventional concrete in solar cells in polygon conditions, thermal treatment of ordinary concrete, polystyrene concrete, arbolite with the use of a solar system with an intermediate coolant at landfills and in closed shops, heat treatment of ordinary concrete, polystyrene concrete, arbolite at polygons in helioforms with energy duplication through solar modules, thermal treatment of foam concrete with the use of solar and electric energy at landfills. The use of solar energy for heat treatment of various concretes is a new energy-efficient promising direction, developed by scientists of Korkyt Ata Kyzylorda state university. The use of solar technology makes it possible to save 50-100% of traditional fuels with an environmentally friendly environment, without emissions from fuel combustion, high quality and low cost of concrete products and structures. All developed technologies of the university are aimed at reducing the impact on the environment, energy- and resource saving and achieving a high level of quality for life for the population. As a whole, the scientists of the Korkyt Ata Kyzylorda state university, see the formula for the development of science in the new decade sustainable development of Kazakhstan in the future.
EXPERIMENTAL INVESTIGATIONS OF CUTTING PARAMETERS INFLUENCE ON SURFACE ROUGHNESS IN MACHINING TITANIUM ALLOY (Ti-6Al-4V) USING TiAlN PVD COATED CARBIDE INSERTS UNDER DRY ENVIRONMENT
In the machining of titanium alloys productivity is adversely affected by rapid tool wear as a consequence of high cutting zone temperature. Recently, dry cutting is becoming increasingly more popular as a means of reducing overhead costs while protecting the environment. From environmental perspective, dry cutting can be characterized as green machining. Reducing or eliminating when possible the use of cutting fluids in green machining means less waste dumped in landfills, less mist in the factory atmosphere, no residue on the chip which will be reflected in reducing disposal and cleaning cost, cleaner workshop floors, and fewer dermatological problem for operators. Dry cutting is ecologically desirable and it will be considered as a necessity for manufacturing enterprises in the near future; therefore, the studies on the machinability of titanium and its alloys under green machining are urgently essential. For that purpose, the performance of PVD-coated carbide tool in green turning of aviation material Ti-64 (36Rc) is undertaken in this study.
In addition response surface model for surface roughness has also been developed. The model predictions have found to agree with the experimental results.