RESUMO
Developing cities like Khulna, the third largest metropolitan city in Bangladesh, have now begun to confess the environmental and public health risks associated with uncontrolled dumping of solid wastes mainly due to the active participation of non-governmental organizations [NGOs] and community-based organizations [CBOs] in municipal solid waste [MSW] management. A survey was conducted to observe the present scenarios of secondary disposal site [SDS], ultimate disposal site [UDS], composting plants, medical wastes management and NGOs and CBOs MSW management activities. A total of 22 NGOs and CBOs are involved in MSW management in 31 wards of Khulna City Corporation. About 9 to 12% of total generated wastes are collected by door-to-door collection system provided by mainly NGOs and CBOs using 71 non-motorized rickshaw vans. A major portion of collected wastes is disposed to the nearest SDS by these organizations and then transferred to UDS or to private low-lying lands from there by the city authority. A small portion of organic wastes is going to the composting plants of NGOs. The participation of NGOs and CBOs has improved the overall MSW management system, especially waste collection process from sources and able to motivate the residents to store the waste properly and to keep clean the premises
Assuntos
Organizações , Poluição Ambiental , Eliminação de Resíduos , Países em DesenvolvimentoRESUMO
In this work a field study was conducted to evaluate the effect of coloured plastic mulch on growth and yield of chilli from October 2005 to April 2006. The plastic mulches were transparent, blue, and black and bare soil was the control. Different mulches generated higher soil temperature and soil moisture under mulch over the control. Transparent and blue plastic mulches encouraged weed population which were suppressed under black plastic. Plant height, number of primary branches, stem base diameter, number of leaves and yield were better for the plants on plastic. At the mature green stage, fruits had the highest vitamin-C content on the black plastic. Mulching produced the fruits with the highest chlorophyll-a, chlorophyll-b and total chlorophyll contents and also increased the number of fruits per plant and yield. However, mulching did not affect the length and diameter of the fruits and number of seeds per fruit. Plants on black plastic mulch had the maximum number of fruits and highest yield. Thus, mulching appears to be a viable tool to increase the chilli production under tropical conditions.
RESUMO
A total of 7690 tons of municipal solid waste generated daily at the six major cities of Bangladesh, namely, Dhaka, Chittagong, Khulna, Rajshahi, Barisal and Sylhet, as estimated in 2005. Sampling was done at different waste generation sources such as residential, commercial, institutional and open areas, in different seasons. The composition of the entire waste stream was about 74.4% organic matter, 9.1% paper, 3.5% plastic, 1.9% textile and wood, 0.8% leather and rubber, 1.5% metal, 0.8% glass and 8% other waste. The per capita generation of municipal solid waste was ranged from 0.325 to 0.485 kg/cap/day while the average rate was 0.387 kg/cap/day as measured in the six major cities. The potential for waste recovery and reduction based on the waste characteristics are evaluated and it is predicted that 21.64 million US$/yr can be earned from recycling and composting of municipal solid waste