The health and environmental consciousness of waste tires has increased tremendously over the years. This has motivated efforts to develop secondary applications that will utilize tire when they reach the end of their life cycle and limit their disposal in landfills. Among the applications of waste tires which are discussed in this review, the use of rubber crumbs in artificial turf fields has gained worldwide attention and is increasing annually. However, there are serious concerns regarding chemicals that are used in the manufacturing process of tires, which ultimately end up in rubber crumbs. Chemicals such as polycyclic aromatic hydrocarbons (PAH) and heavy metals which are found in rubber crumbs have been identified as harmful to human health and the environment. This review paper is intended to highlight some of the methods which have been used to manage waste tire; it also looks at chemicals/materials used in tire compounding which are identified as possible carcinogenic.
We assessed the quality and pollution status of source surface waters in Zaria, Nigeria by monitoring the nature, cause and
extent of pollution in Samaru stream, Kubanni River and Kubanni dam over a period of 10 months, between March and December
2002. A total of 228 water samples was collected from 12 sites and analysed for a total of ten physicochemical and one bacteriological
quality indicators, using standard methods. Aesthetic water quality impairment parameters were also observed. The mean values
of most water quality parameters were significantly higher (P < 0.05) in both the stream and river than in the dam. There was no significant correlation between faecal coliform counts
(FCC) and water temperature (in the range 15–33°C); pH (5.77–7.32); and turbidity (1.4–567 NTU). The high FCC ranged from
2.0 × 101 to 1.6 × 106 MPN/100 ml and exceeded the WHO standards for drinking water and water used for fresh-produce irrigation, and correlated
positively (P < 0.05) with conductivity (in the range 68–1,029 μS/cm); TDS (10.0–70.0 mg/l); TSS (10.0–70.0 mg/l); Cl (7.5–181 mg/l); PO4−P (0.01–0.41 mg/l); NO3−N (0.6–3.8 mg/l) and BOD5 (0.1–14.9 mg/l). The main pollution sources were municipal wastewater, stormwater runoffs, the ABU sewage treatment plant,
abattoir effluents and irrigation farms treated with chemical fertilisers. We conclude that these water bodies are potentially
hazardous to public health and that proper sewage treatment and river quality monitoring are needed to warn against hazards
to public health. 相似文献
This work centered on a 1-year evaluation campaign of point source pollution from a sewage treatment oxidation pond and its receiving stream. Water samples were collected from the sewage treatment oxidation pond and the receiving stream during July 2002 and June 2003. Concentrations of heavy metals were determined using Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) after a triple acid digestion of samples using open beaker method. Generally, the results showed high levels of toxic metals such as Cd, Pb, As, Al, Cr, Mn, Co, and Fe in the influent and effluent samples as well as in the receiving stream. The annual mean concentration of metals in the sewage samples ranged from 11.90 to 16.05, 64.96 to 88.27, 38.91 to 76.35, 17.46 to 24.45 mug/L for Cd, As, Pb, Co, and 4.31 to 8.77, 1.71 to 2.45, 0.46 to 0.74 and 13.82 to 20.47 mg/l for Al, Cr, Mn and Fe, respectively; while in the receiving stream, the concentrations were between 6.89 to 10.45, 35.50 to 59.26, 22.85 to 35.94, 11.33 to 18.83 mug/l for Cd, As, Pb, Co, and 1.99 to 3.49, 1.35 to 2.08, 0.21 to 0.48, and 8.93 to 14.15 mg/l for Al, Cr, Mn and Fe, respectively. The discharge of the effluent from the sewage pond into the receiving stream has therefore led to increase in the concentrations of some heavy metals downstream, thus impacting the receiving stream negatively and could pose a serious health hazard to aquatic ecosystems and humans particularly for rural dwellers and peasant farmers downstream that utilize the water from the receiving stream for various domestic and agricultural purposes untreated. 相似文献
We assessed the biodegradation of a typical oily sludge waste (PB401) in Mexico using several regimes of indigenous microbial consortium and relevant bioremediation strategies in slurry-phase system. Abiotic loss of total petroleum hydrocarbons (TPH) in the PB401 was insignificant, and degradation rates under the various treatment conditions ranged between 666.9 and 2168.7 mg kg(-1) day(-1) over a 15 days reaction period, while viable cell count peaked at between log(10)5.7 and log(10)7.4 cfu g(-1). Biostimulation with a commercial fertilizer resulted in 24% biodegradation of the TPH in the oily waste and a corresponding peak cell density of log(10)7.4 cfu g(-1). Addition of non-indigenous adapted consortium did not appear to enhance the removal of TPH from the oily waste. It would appear that the complexities of the components of the alkylaromatic fraction of the waste limited biodegradation rate even in a slurry system. 相似文献