Water quality for agriculture , Water quality for agriculture , مرکز فناوری اطلاعات و اطلاع رسانی کشاورزی

Water quality for agriculture

https://www.thelancet.com/pdfs/journals/lancet/PIIS0140-6736(07)60076-2.pdf

Child development: risk factors for adverse outcomes in developing countries

Physico-chemical treatment techniques for wastewater laden with heavy metals

At present and more so in the future, irrigated agriculture will take place under water scarcity. Insufficient water supply for irrigation will be the norm rather than the exception, and irrigation management will shift from emphasizing production per unit area towards maximizing the production per unit of water consumed, the water productivity. To cope with scarce supplies, deficit irrigation, defined as the application of water below full crop-water requirements (evapotranspiration), is an important tool to achieve the goal of reducing irrigation water use. While deficit irrigation is widely practised over millions of hectares for a number of reasons—from inadequate network design to excessive irrigation expansion relative to catchment supplies—it has not received sufficient attention in research. Its use in reducing water consumption for biomass production, and for irrigation of annual and perennial crops is reviewed here. There is potential for improving water productivity in many field crops and there is sufficient information for defining the best deficit irrigation strategy for many situations. One conclusion is that the level of irrigation supply under deficit irrigation should be relatively high in most cases, one that permits achieving 60–100% of full evapotranspiration. Several cases on the successful use of regulated deficit irrigation (RDI) in fruit trees and vines are reviewed, showing that RDI not only increases water productivity, but also farmers’ profits. Research linking the physiological basis of these responses to the design of RDI strategies is likely to have a significant impact in increasing its adoption in water-limited areas.

Deficit irrigation for reducing agricultural water use

http://fac.ksu.edu.sa/sites/default/files/Abdel-Raouf%20et%20al%2C2012.pdf

Microalgae and wastewater treatment.

Waste stabilisation pond decommissioning: a painful but necessary decision

Despite the considerable research effort put into understanding the physicochemical and in particular the biological interactions occuring in waste stabilization ponds their design still remains conservative and based on long established criteria for the efficient functioning of industrial process reactors. The assumption that complete mixing improves treatment efficiency in ponds is questioned in favour of allowing stratification to occur to improve bacterial pathogen removal in maturation ponds and possibly BOD removal in facultative ponds. Excessive mixing in anaerobic ponds is likely to increase the risk of odour release and may reduce sludge digestion by inhibiting methanogenisis. Shallow maturation ponds favour the formation of high pH concltions which promote bacterial die-off and may further assist any synergistic effects between high pH and light. The construction of large ponds is critisized in favour of the use of more, smaller ponds, aligned in parallel at all stages in the series. The stimulation of zoopiankton grazing of microaigae to improve effluent quality is discussed and the use of variable height inlet and outlet structures in all ponds is recommended. The need for operational data on radical new pond designs collected so as to allow detailed analysis of the results fa worldwide application is stressed as a research priority

Rationalizing waste stabilization pond design: the biological factor

Marine-based waste stabilisation ponds: an evaluation of the hydraulic viability.

The ventilated improved pit (VIP) latrine is now widely recognized as one of the most important, affordable and appropriate on-site sanitation technologies for use in both urban and rural areas of developing countries. The Technology Advisory Group (TAG) has been one of the major agencies responsible for its promotion in several countries (principally in Africa and South America) and has published several technical notes describing the design of various types of VIP latrines. This discussion paper provides guidelines that will enable a design engineer to make a rational selection of the VIP latrine design option most appropriate to the community for which they are responsible. The designer is aiming at a technical choice that will be affordable to the householder and will give the best long-term service at the least cost. It is assumed for the purpose of this paper that a VIP latrine of some sort is the most appropriate sanitation facility for the community under consideration, and also that the reader is aware of how VIP latrines function and how they are able to control odors and insects. What remains for the designer is to select the type of VIP latrine that is compatible with available resources as well as with the prevailing physical, socio-cultural, institutional, economic and financial conditions. In doing so, special emphasis is placed on technology costs and affordability.

Ventilated improved pit latrines : guidelines for the selection of design options

I read with great interest the article by Ng and others entitled “Assessing the contribution of malaria vector control and other maternal and child health interventions in reducing all-cause under-five mortality in Zambia.” Considering that malaria was possibly not the most important cause of death in children under 5 years of age (U5) in Zambia, and that maternal and child health interventions were possibly not the most important cause of the decline in U5 deaths, I checked the data in global burden of disease (GBD) Compare, the data visualization hub on the Institute of Health Metrics and Evaluation website. The information I obtained (in under an hour—such is the power of GBD Compare) is given in Table 1. In fact, neonatal disorders were the most important causes of U5 deaths in 2010 and 2013 (malaria was most important in 2000), although childhood undernutrition was the most important risk factor. One striking feature in Table 1 is that U5 deaths have been a very high, but decreasing, proportion of total all-age deaths: 39.2% in 2000, 35.4% in 2010, and 33.3% in 2013. A potentially more informative metric is disability-adjusted life year (DALY) losses. Table 2 shows the DALY losses in 2000, 2010, and 2013 for the causes and risk factors considered in Table 1. This shows a similar ranking of cause and risk factor, and an extremely high, but decreasing, proportion of the overall burden of disease in the U5s: 51.1% in 2000, 47.6% in 2010, and 45.0% in 2013. What do Tables 1 and 2 tell us about disease priorities? What can Zambia do to reduce U5 deaths and the U5 burden of disease? Obviously, the good work on reducing malarial deaths must be continued. Childhood nutrition is clearly a major issue, including stunting (2,278 U5 deaths in 2013), underweight (5,186), wasting (12,199), suboptimal breastfeeding (4,135 U5 deaths in 2013), and nutritional deficiencies (4,671). Infantand child-feeding programs should be established, together with nutrition education for mothers and mothers-to-be. Stunting is strongly associated with unsafe water, sanitation, and hygiene (WASH), especially unsafe sanitation. Environmental enteropathy is the principal pathway for this association, which is exacerbated by open defecation (OD). In Zambia, 22% of the rural population—about 2 million people—practices OD. The elimination of OD is part of the sustainable development goals; and therefore, Zambia needs to get its rural population served with at least basic, and preferably safely-managed, sanitation by 2030. Lower respiratory-tract infections, particularly pneumonia, exert a high burden of disease and death in the U5s. Pneumococcal conjugate vaccine was launched only in mid-2013, so it is too early to say how successful this program will be. Neonatal disorders are very important. Deaths due to neonatal sepsis and other neonatal infections have been rising steadily from 2,121 in 2000 to 2,704 in 2013. This may reflect poor WASH, the difficulty of accessing even basic-level health-care facilities in rural areas, and/or rural mothers not recognizing early symptoms of these diseases. Poor WASH should be addressed, as it is known to adversely affect maternal, infant, and child mortality. There also needs to be improved rural health care and targeted health/hygiene education for mothers and mothers-to-be. Diarrheal diseases caused significantly fewer deaths in 2013 than in 2000. This parallels the decrease in unsafe water, unsafe sanitation, and unsafe hand hygiene, which must be sustained. The most dramatic decrease, nearly 60%, was seen in the number of human immunodeficiency virus, acquired immune deficiency syndrome, and tuberculosis deaths during 2010–2013. This truly excellent performance needs, of course, to continue. As highlighted in this letter, an initial broad-brush approach using GBD Compare (or similar tools) is likely to produce good guidance on health priorities, especially in rural areas and periurban slums. Targeted detail can then follow.

/pdf/disease-priorities-in-zambia-3limz9zbmi.pdf

Duncan Mara

Papers

Waste stabilisation pond decommissioning: a painful but necessary decision

Rationalizing waste stabilization pond design: the biological factor

Marine-based waste stabilisation ponds: an evaluation of the hydraulic viability.

Ventilated improved pit latrines : guidelines for the selection of design options

Disease Priorities in Zambia.