scholarly journals Influence of volumetric loading rate on aerobic sewage treatment for indigenous algal growth

2019 ◽  
Vol 80 (7) ◽  
pp. 1287-1294
Author(s):  
L. Mendoza ◽  
M. M. Aray-Andrade ◽  
R. Bermudez ◽  
J. Amaya ◽  
L. Zhang ◽  
...  
Keyword(s):  
Developing Countries ◽  
Rural Areas ◽  
Sewage Treatment ◽  
Algal Growth ◽  
Organic N ◽  
Yield Coefficient ◽  
Partial Recovery ◽  
Economic Resource ◽  
Chlorella Sp ◽  
Volumetric Loading

Abstract Many rural areas of Latin America and the Caribbean (LAC) region are economically depressed. Rural sewage treatment in most areas of LAC is deficient or non-existent. Consequently, the possibility of generating economic revenue from treated sewage is an attractive option for deprived areas of developing countries. Given its peculiar characteristics, rural sewage may be coupled with biological systems such as algae for nutrient cycling. Acceptable algae growth and nutrient elimination were obtained from rural sewage whose treatment may have fallen short of current disposal standards. In this study, aerobic systems working on an 8-month cycle at three different volumetric loading rates (Bv) were assessed in relation to the lifetime growth of three algae strains native to Ecuador. Results indicate Chlorella sp. M2 as the optimal algal strain, with the highest growth rate at Bv of 1 g COD L−1 d−1 and a removal of organic-N (30%), PO43–-P (87%) and NH4+-N (95%). Concomitantly, the kinetic constants of the sewage resulted in a low biomass yield coefficient, making the proposed system highly suitable for developing countries. Finally, the proposed partial recovery stream method, combining nutrient recovery with economic resource generation, appears to contain great potential.

Management of Water Cycle: An Approach to Urban Ecology

1992 ◽  
Vol 27 (2) ◽  
pp. 221-238 ◽  
Author(s):  
W. Ripl
Keyword(s):  
Rural Areas ◽  
Urban Areas ◽  
Water Cycle ◽  
Cooling System ◽  
Thermal Power ◽  
Sewage Treatment ◽  
Balance Sheet ◽  
River System ◽  
Soil Restoration ◽  
Environmental Damage

Abstract Densely populated urban areas, which have developed over the last century, depend heavily on centralized water supply, sewage treatment plants, and hydroelectric or thermal power generation with vast demand of cooling water. Considerable areas have been drained or sealed, and the short-circuited water cycle has been distorted. Large rivers have been converted to shipping canals with the permanent risk of accidental pollution. Technical means such as sewage treatment, air filters, emission control and lake and soil restoration measures have contributed to correct the environmental damage. However, a balance sheet for irreversible matter losses (mainly base cation charges) from the urbanized areas and the surrounding landscape into the sea shows ever-increasing trends. These losses are destabilizing the ecosystems. In this paper, management of the water cycle in urban areas, together with the coupled matter cycles, is discussed. Particular reference is given to Metropolitan Berlin, with a network of shipping canals, which move biologically treated waste, containing base cations and nutrients to the surrounding rural areas. This could create manageable productive wetlands and re-establish soil fertility. At the same time, the natural cooling system close to the urban areas will be improved by providing more areas with permanent vegetation. In addition, reduction of the present large oscillations of the groundwater table, resulting from groundwater pumping and its recharge with less polluted surface water, is contemplated. The widely used shoreline infiltration of the Havel River should then be eliminated and the severe damage of the littoral vegetation in large sections of the Havel River system be avoided.

Sewage Treatment in Helophyte Beds–First Experiences with a New Treatment Procedure

1987 ◽  
Vol 19 (10) ◽  
pp. 1-10 ◽  
Author(s):  
K. Bucksteeg
Keyword(s):  
Waste Water ◽  
Rural Areas ◽  
Root Zone ◽  
Waste Water Treatment ◽  
Sewage Treatment ◽  
Uptake Capacity ◽  
Humid Climate ◽  
Climate Conditions ◽  
Trickling Filters ◽  
Operation Conditions

Waste water treatment in helophyte beds under humid climate conditions has been favoured by some German ecologists for some years. The idea is to cause waste water to flow horizontally through the root zone of helophytes to achieve satisfactory effluent properties. There exist many highly different proposals regarding the choice of soil and helophytes to be applied, bed area, design of inlets and outlets and operation conditions. A few plants have been operated in practice for some years. It appears that clogging is one of the main problems occurring in these plants. The hydraulic uptake capacity of soil is discussed in Darcy's law. Comparisons with observations of plants in operation are drawn. The interactions between soil properties, its uptake capacity, BOD5-, COD-, N- and P-reduction are evaluated. The effluent results of helophyte beds are compared with those of low-loaded trickling filters and of ponds used for sewage treatment in small villages in rural areas of Germany. It has been proved that the total construction costs of sewage treatment plants with helophyte beds used as the biological stage are higher when compared with those of conventional plants in general.

Sludge Treatment and Disposal Systems for Rural Areas in Germany

1993 ◽  
Vol 27 (9) ◽  
pp. 159-171 ◽  
Author(s):  
Eberhard Steinle
Keyword(s):  
Sewage Sludge ◽  
Rural Areas ◽  
Public Awareness ◽  
Sewage Treatment ◽  
Treatment Needs ◽  
Sludge Treatment ◽  
Sewage Treatment Plants ◽  
Sewage Purification ◽  
Treatment And Disposal ◽  
Nitrogen Phosphorus

First an overview of the systems currently in use and being discussed for sludge treatment is presented will) particular emphasis on distinguishing between the object of the system (conditioning objective of the various phases in the system) and a system concept (concept of various phases of the system in sequence to attain the disposal objective). More detailed information is given as to the salient systems as used with smaller sewage treatment plants in rural areas, such as digestion, dewatering, hygienization, composting and thermal drying. A further item of discussion is how sludge treatment influences the sewage treatment process. For the critical emissions (nitrogen, phosphorus) demanded in Germany, and thus for the degree of sewage treatment required, the load of the sewage treatment system resulting from sludge treatment needs to be taken into account. Accordingly, operation of sludge treatment and sewage purification must always be harmonized. The extent of these return loads also limits the spatial centralization of the system phases; this applies in particular to smaller sewage treatment plants in rural areas. In conclusion, an attempt is made to present a perspective for the agricultural utilization of such sludge in Germany. Since the critical values for emissions have been further tightened by new regulations, thus considerably elevating the associated sophistication of monitoring techniques, it is to be expected that the use of sewage sludge in agriculture will also be further reduced in rural areas, especially since public awareness of emission control has considerably reduced the acceptance of sewage sludge as fertilizer.

Relating Household Consumption Expenditures to Road Traffic Fatalities: A Rural–Urban Study

2021 ◽  
pp. 036119812110332
Author(s):  
Ruchika Agarwala ◽  
Vinod Vasudevan
Keyword(s):  
Developing Countries ◽  
Traffic Safety ◽  
Rural Areas ◽  
Urban Areas ◽  
Household Consumption ◽  
Household Expenditure ◽  
Traffic Fatality ◽  
Rural And Urban Areas ◽  
Rural And Urban ◽  
The Relationship

Research shows that traffic fatality risk is generally higher in rural areas than in urban areas. In developing countries, vehicle ownership and investments in public transportation typically increase with economic growth. These two factors together increase the vehicle population, which in turn affects traffic safety. This paper presents a study focused on the relationship of various factors—including household consumption expenditure data—with traffic fatality in rural and urban areas and thereby aims to fill some of the gaps in the literature. One such gap is the impacts of personal and non-personal modes of travel on traffic safety in rural versus urban areas in developing countries which remains unexplored. An exhaustive panel data modeling approach is adopted. One important finding of this study is that evidence exists of a contrasting relationship between household expenditure and traffic fatality in rural and urban areas. The relationship between household expenditure and traffic fatality is observed to be positive in rural areas and a negative in urban areas. Increases in most expenditure variables, such as fuel, non-personal modes of travel, and two-wheeler expenditures, are found to be associated with an increase in traffic fatality in rural areas.

scholarly journals The Extent of Heat on Health and Sustainable Farming in Ghana –Bawku East

2014 ◽  
Vol 3 (3) ◽  
pp. 56 ◽  
Author(s):  
Frimpong Kwasi ◽  
Jacque Oosthuizen ◽  
Eddie Van Etten
Keyword(s):  
Developing Countries ◽  
Health Effects ◽  
Rural Areas ◽  
High Heat ◽  
Northern Ghana ◽  
Tropical Regions ◽  
Wet Bulb Globe Temperature ◽  
Time Period ◽  
Outdoor Work ◽  
Globe Temperature

<p>Little is known about the health effects of heat in outdoor work and appropriate work and rest schedules for farmers working in developing countries. As temperatures continue to increase in tropical regions, such as Northern Ghana, it is necessary to evaluate how farmers experience and respond to high heat exposures. In this study, WBGT (Wet Bulb Globe Temperature) estimates and the ISO work / rest standards were applied to a cohort of farmers in the rural areas of Bawku East, Northern Ghana, to assess how farmers respond to high heat and how much they rest to protect their health, as well as the level of heat on their productivity. WBGT data was recorded over a period of 6 months among vegetable, cereals, and legume farmers. The ISO proposed and actual rest regimes observed by farmers in the same time period were evaluated. In the dry season the dry bulb temperature rose as high as 45 ºC, while during the humid months of March and April WBGT rose to levels as high as 34 ºC. Farmers worked for nine hours a day during these hot periods with insufficient rest, which has adverse consequences on their health and productivity.</p>

Acute Pituitary Apoplexy following Snake Bite: A Rare but Treatable Complication

2017 ◽  
Vol 16 (06) ◽  
pp. 397-399
Author(s):  
Narendrakumar Barad
Keyword(s):  
Public Health ◽  
Acute Kidney Injury ◽  
Developing Countries ◽  
Rural Areas ◽  
Pituitary Apoplexy ◽  
Kidney Injury ◽  
Snake Bite ◽  
Important Public Health ◽  
Russell’S Viper ◽  
Public Health Hazards

AbstractPoisonous snake bite is one of the important public health hazards in developing countries, such as India, where majority of the population resides in rural areas. Among various poisonous species of snakes, Russell's viper venom causes neurotoxicity, myotoxicity, hemolysis, and coagulopathies leading to shock and acute kidney injury. Pituitary apoplexy causing acute hypopituitarism is an extremely rare but treatable complication following viper bite. Here in, we report the case of a 14-year-old boy admitted with Russell's viper bite complicated by disseminated intravascular coagulation (DIC), acute kidney injury, and pituitary apoplexy with secondary acute hypopituitarism.

COD removal efficiency and mechanism of HMBR in high volumetric loading for ship domestic sewage treatment

2016 ◽  
Vol 74 (7) ◽  
pp. 1509-1517 ◽  
Author(s):  
Linan Zhu ◽  
Hailing He ◽  
Chunli Wang
Keyword(s):  
Removal Efficiency ◽  
Removal Rate ◽  
Sewage Treatment ◽  
Oxygen Demand ◽  
Domestic Sewage ◽  
Cod Removal ◽  
Aeration Tank ◽  
Remarkable Effect ◽  
Cod Removal Efficiency ◽  
Volumetric Loading

The hybrid membrane bioreactor (HMBR) has been applied in ship domestic sewage treatment under high volumetric loading for ship space saving. The mechanism and influence factors on the efficiency, including hydraulic retention time (HRT), dissolved oxygen (DO) of chemical oxygen demand (COD) removal were investigated. The HMBR's average COD removal rate was up to 95.13% on volumetric loading of 2.4 kgCOD/(m3•d) and the COD concentration in the effluent was 48.5 mg/L, far below the International Maritime Organization (IMO) discharge standard of 125 mg/L. DO had a more remarkable effect on the COD removal efficiency than HRT. In addition, HMBR revealed an excellent capability of resisting organics loading impact. Within the range of volumetric loading of 0.72 to 4.8 kg COD/(m3•d), the effluent COD concentration satisfied the discharge requirement of IMO. It was found that the organics degradation in the aeration tank followed the first-order reaction, with obtained kinetic parameters of vmax (2.79 d−1) and Ks (395 mg/L). The original finding of this study had shown the effectiveness of HMBR in organic contaminant degradation at high substrate concentration, which can be used as guidance in the full scale of the design, operation and maintenance of ship domestic sewage treatment devices.

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