摘要：
The unquenchable demand for rock materials has attracted many companies within the building and construction sector to invest in stone quarrying. However, this has brought about environmental impacts with health threats to people. There is a paucity of information about the magnitude of pollution on air and water and how it varies with quarry sites. This study, therefore, investigated the physical impacts of quarrying on air and water and explored the in-situ mitigations to undesirable effects due to stone quarrying. Four active quarry sites were identified. Field measurements of dust (particulate matter) were conducted within the four quarry sites and in the nearby community. Water samples were collected from quarry pits and nearby shallow wells for laboratory analysis of water quality. Statistical Analysis of Variance (ANOVA) was used to test for differences in pollution across the four studied sites. Results revealed that, amidst the use of wet crushing and water sprinkling on bare surfaces, dust emission was higher than the recommended permissible standards levels with a significant variation across the quarry sites with ANOVA (P-value = 0.003) for PM 2.5 and (P-value = 0.04366) for PM 10. Water pollution was mainly contributed by the non-permissive levels of nitrates, chromium, and pH. Polluted air and water are associated with sparking off health threats to the users in the community. In conclusion, quarry companies should strengthen the already existing mitigation of dust suppression. The study recommends additional measures such as treating quarry pit water before discharging to the open environment to enhance environmental protection against the accumulating undesirable quarry impacts.
摘要：
汽車尾氣排放是空氣污染最主要的來(lái)源之一,已有技術(shù)以機(jī)內(nèi)凈化技術(shù)和機(jī)外凈化技術(shù)為主,少有關(guān)注如何從發(fā)動(dòng)機(jī)前端入手減少汽車尾氣污染物排放。Warp Air Clean(WAC)裝置可以通過(guò)靜電作用改善發(fā)動(dòng)機(jī)進(jìn)氣質(zhì)量,優(yōu)化發(fā)動(dòng)機(jī)燃燒過(guò)程,因此基于國(guó)五Ⅰ型測(cè)試進(jìn)行了WAC裝置減排效果研究。結(jié)果表明:(1)WAC裝置對(duì)汽油車尾氣排放的總碳?xì)浠衔?THC)、CO、氮氧化物(NO_(x))、顆粒物(PM)、CH_(4)和非甲烷總烴(NMHC)都有著較好的減排效果;(2)總體而言,WAC裝置對(duì)汽油車舊車的減排效果優(yōu)于新車;(3)對(duì)汽油車THC、CH_(4)和NMHC的市區(qū)工況減排效果優(yōu)于市郊工況,而對(duì)CO和NO_(x)的市郊工況減排效果優(yōu)于市區(qū)工況;(4)對(duì)不超過(guò)九座的載客車輛的減排效果優(yōu)于最大設(shè)計(jì)總質(zhì)量不超過(guò)3500 kg的載貨車輛。
摘要：
After lunch,Rick and Mary were waiting for Uncle George.He had promised to see them and to talk with them in the den as soon as he had finished a phone call.They wanted to learn more about the weather.
摘要：
Air quality is one of key issues to be addressed in the Vietnam environmental security strategy. As part of the strategy, this study investigates the temporal patterns of PM2.5 variations in Hanoi using data measured from January 2017 to December 2018. The loglinear regression is used to analyze how the meteorological factors affect the PM2.5 variations. The analysis indicates the seasonal, monthly and diurnal variations of PM2.5 concentrations. The lowest concentration level is found in the summer due to hot climatic conditions with strong winds and high solar radiation. The highest PM2.5 concentration is observed in winter as a result of stagnation. The concentration levels from 2:00 AM to 8:00 AM tend to be higher than other hours of the day while the downtrend is recorded from 11:00 AM to 7:00 PM and reaches the lowest levels of the day at 2:00 PM to 3:00 PM. The study results provide important information for government authorities, international and civil society organizations on when and why the PM2.5 concentration levels increase. This predictive analysis would be useful to develop early warning systems and to minimize the negative impacts of air pollution on public health.
摘要：
Land reclamation is gradually posing negative impact on man due to unplanned urbanization. A study was carried out on impact of land reclamation through sand mining of coastal communities in Ikate and Ilubirin in Lagos, Nigeria. Ten waters (8 surface and 2 groundwater sources), 10 soil samples and air were collected and taken for analysis. Results of water revealed concentrations lower than WHO (2017) and SON (2007) standards. Soil/sediment with average crustal value revealed Pb and Cd above standard values, which is attributed to anthropogenic influence on soils. Quality of air in the study was mainly particulate matter arising from the sea and reclaimed land in the surroundings of the environment with the highest Total Suspended Particulate of 0.8 mg/m3 in sulfur dioxide. This explains corrosion found on the roofs of the communities. Therefore, in the development planning adequate precautions should be put in place to avert environmental degradation.
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