Effect of dissolved oxygen in reclaimed wastewater transformation during transportation. Case study: Tenerife, Spain

1998 ◽  
Vol 37 (1) ◽  
pp. 123-130 ◽  
Author(s):  
S. Delgado ◽  
M. Alvarez ◽  
E. Aguiar ◽  
L.E. Rodríguez-Gómez

During treated wastewater transport, phenomena related to the presence or absence of dissolved oxygen (DO) have been observed. In Tenerife reclaimed urban wastewater (RUWW) transport from the capital, Santa Cruz to the south of the island for agriculture reuse was studied. Anoxic conditions and H2S generation were noted during transport. As RUWW has an electrical conductivity (EC) of about 1600 μS/cm, BALTEN decided to add fresh water (FW) with low EC, saturated or over saturated in DO at an intermediate point in the pipe to reduce the conductivity of water supplied to agriculture, also thus reducing the organic load and consequently H2S generation. However, injection of DO over-saturated fresh water brought on the appearance of nitrification and later denitrification. A study was carried out of H2S generation, nitrification and denitrification during RUWW transport with and without added FW.

2021 ◽  
Vol 7 (4) ◽  
pp. 1-22
Author(s):  
Mukasa Tebandeke I.Z ◽  
Karume I ◽  
Ssebuwufu J ◽  
Wasajja H.Z ◽  
Nankinga R ◽  
...  

Pollution resulting from unsustainable agricultural and urbanization activities in the Ruhezamyenda and Bunyonyi catchments are threatening lake Bunyonyi. These have led to high chemical oxygen demand (COD), electrical conductivity, turbidity, pH, iron (II) concentration and low dissolved oxygen (DO5). In this study we have investigated the how COD, turbidity, pH, concentration of iron, total suspended solids, total nutrients and DO5 of water changed with distance in lake. Water sampled from different distances in the lake filtered using Whatman paper at ambient temperatures was tested for COD, electrical conductivity, turbidity, total nutrients, iron, hardness and DO5. COD was 20.8±.0.03mg/L to 16 ± 0.03mg/L; total hardness was 16.5±0.2 mg/L to 18.6 ± 0.3 mg/L total nitrate was 103.5± 2 mg/L to 88 ± 3 mg/L; total phosphate was 100.8 ±.2.5 to 87± 3 mg/L; high TSS values from 3.4 ± 0.1 mg/L to 2.5 ± 0.1 mg/L showed contamination of water. As pH decreased from 8.3 ± 0.03 to 7.6 ± 0.04 revealed that bases were getting removed. The turbidity dropped from 25.7 ± 0.3 NTU to 20 ± 2 NTU due settling down of sediments. Iron (II) concentration ranging from 1.1± 0.1 to 0.8± 0.1 mgL-1 . Dissolved oxygen decreased from 7.9 ±0.3 mg/L to 4.8 ± 0.2 mg/L indicating surface water can uphold life of aquatic organisms. Total hardness ranged from 0.22± 0.05 to 0.19± 0.05 mg/L Electrical conductivity was high and ranged from 130± 5 to 150± 5 µS/cm indicating presence of electrolytes. Lake Bunyonyi water is not greatly polluted, but requires to be safe guarded against poor unsustainable agricultural practices, sewage draining from towns, schools and hotels in nearby settlements.


Water ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1276 ◽  
Author(s):  
Motasem N. Saidan ◽  
Mohammad Al-Addous ◽  
Radwan A. Al-Weshah ◽  
Ibrahim Obada ◽  
Malek Alkasrawi ◽  
...  

Water scarcity remains the major looming challenge that is facing Jordan. Wastewater reclamation is considered as an alternative source of fresh water in semi-arid areas with water shortage or increased consumption. In the present study, the current status of wastewater reclamation and reuse in Jordan was analyzed considering 30 wastewater treatment plants (WWTPs). The assessment was based on the WWWTPs’ treatment processes in Jordan, the flowrates scale, and the effluents’ average total dissolved solid (TDS) contents. Accordingly, 60% of the WWTPs in Jordan used activated sludge as a treatment technology; 30 WWTPs were small scale (˂1 × 104 m3/day); and a total of 17.932 million m3 treated wastewater had low TDS (˂1000 ppm) that generally can be used in industries with relatively minimal cost of treatment. Moreover, the analysis classified the 26 million m3 groundwater abstraction by major industries in Jordanian governorates. The results showed that the reclaimed wastewater can fully offset the industrial demand of fresh water in Amman, Zarqa, and Aqaba governorates. Hence, the environmental assessment showed positive impacts of reclaimed wastewater reuse scenario in terms of water depletion (saving of 72.55 million m3 groundwater per year) and climate change (17.683 million kg CO2Eq reduction). The energy recovery assessment in the small- and medium-scale WWTPs (˂10 × 104 m3/day) revealed that generation of electricity by anaerobic sludge digestion equates potentially to an offset of 0.11–0.53 kWh/m3. Finally, several barriers and prospects were put forth to help the stakeholders when considering entering into an agreement to supply and/or reuse reclaimed water.


Agronomy ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 649
Author(s):  
Jorge De las Heras ◽  
Pilar Mañas

Having drinking water is one of the sustainable development goals (SDG no. 6) that is not always easy to ensure, especially in countries like Spain or arid regions marked by water deficit. The reuse of treated water should be considered when planning water resources, but it is necessary to verify that this effectiveness is applicable to real situations. A field trial was carried out in several study areas distributed in agricultural parcels of south east Spain. Soils from two olive groves and two vineyards irrigated with treated wastewater (TW) were monitored for to compare with other plantations irrigated with conventional well water (WW) since July 2016–September 2018. Five different irrigation water sources were analyzed (two from well water and three from reclaimed wastewater). No microbiological, metal content, toxicity or organic compounds (PAHs and PCBs) in the studied water samples were detected and reclaimed municipal wastewater was comparable in quality to the conventional sources at all the demonstration sites, except for higher electrical conductivity. Soils irrigated with TW had higher values for electrical conductivity, N, K, Na, Mg, Mn and cation exchange capacity. The main precautions to be considered when irrigating with treated wastewater are its salt content and its tendency to high values of electrical conductivity. Otherwise, they are an interesting contribution of nutrients to soil. Hence adopting this water type to irrigate orchards, vineyards and olive groves could help to save primary water resources.


Erdkunde ◽  
2020 ◽  
Vol 74 (3) ◽  
pp. 191-204
Author(s):  
Marcus Hübscher ◽  
Juana Schulze ◽  
Felix zur Lage ◽  
Johannes Ringel

Short-term rentals such as Airbnb have become a persistent element of today’s urbanism around the globe. The impacts are manifold and differ depending on the context. In cities with a traditionally smaller accommodation market, the impacts might be particularly strong, as Airbnb contributes to ongoing touristification processes. Despite that, small and medium-sized cities have not been in the centre of research so far. This paper focuses on Santa Cruz de Tenerife as a medium-sized Spanish city. Although embedded in the touristic region of the Canary Islands, Santa Cruz is not a tourist city per se but still relies on touristification strategies. This paper aims to expand the knowledge of Airbnb’s spatial patterns in this type of city. The use of data collected from web scraping and geographic information systems (GIS) demonstrates that Airbnb has opened up new tourism markets outside of the centrally established tourist accommodations. It also shows that the price gap between Airbnb and the housing rental market is broadest in neighbourhoods that had not experienced tourism before Airbnb entered the market. In the centre the highest prices and the smallest units are identified, but two peripheral quarters stand out. Anaga Mountains, a natural and rural space, has the highest numbers of Airbnb listings per capita. Suroeste, a suburban quarter, shows the highest growth rates on the rental market, which implies a linkage between Airbnb and suburbanization processes.


1998 ◽  
Vol 38 (1) ◽  
pp. 87-95 ◽  
Author(s):  
M. Roš ◽  
J. Vrtovšek

A combined anaerobic anoxic aerobic reactor for the treatment of the industrial wastewater that contains nitrogen and complex organic compounds as well as its design procedure is presented. The purpose of our experiments was to find a simple methodology that would provide combined reactor design. The reactor is based on the combination of anaerobic, anoxic and aerobic process in one unit only. It was found that the HRT even under 1 hour in the anaerobic zone is long enough for the efficient transformation of complex organic compounds into readily biodegradable COD which is then used in dentrification process. In the N-NO3 concentration range 1.5-50 mg/l the denitrification rate could be expressed as half-order reaction when the CODrb was in excess. N-NO3 removal efficiency is controlled by the recycle flow from the aerobic to the anoxic zone. Nitrification rate can be expressed as first, half or zero-order reaction with respect to effluent N-NH4 concentration. Nitrification rate depends on the dissolved oxygen concentration and hydrodynamic conditions in the reactor. Case study for design of a pilot plant of the combined reactor for treatment of pre-treated pharmaceutical wastewater is shown. Characteristics of pre-treated wastewater were: COD=200 mg/l, BOD5=20 mg/l, N-Kjeldahl=80 mg/l, N-NH4=70 mg/l, N-NOx<1 mg/l, P-PO4=5 mg/l. Legal requirements for treated wastewater were: COD=<100 mg/l, BOD5<5 mg/l, N-NH4=<1 mg/l, N-NOx=<10 mg/l.


1999 ◽  
Vol 40 (4-5) ◽  
pp. 43-50 ◽  
Author(s):  
Marcelo Juanico ◽  
Eran Friedler

Most of the water has been captured in the rivers of Israel and they have turned into dry river-beds which deliver only sporadic winter floods. In a semi-arid country where literally every drop of water is used, reclaimed wastewater is the most feasible water source for river recovery. Two topics are addressed in this paper: water quality management in rivers where most of the flowing water is treated wastewater, and the allocations of reclaimed wastewater required for the recovery of rivers and streams. Water quality management must consider that the main source of water to the river has a pollution loading which reduces its capability to absorb other pollution impacts. The allocation of treated wastewater for the revival of rivers may not affect negatively the water balance of the region; it may eventually improve it. An upstream bruto allocation of 122 MCM/year of wastewater for the recovery of 14 rivers in Israel may favor downstream reuse of this wastewater, resulting in a small neto allocation and in an increase of the water resources available to the country. The discharge of effluents upstream to revive the river followed by their re-capture downstream for irrigation, implies a further stage in the intensification of water reuse.


2000 ◽  
Vol 42 (1-2) ◽  
pp. 75-79 ◽  
Author(s):  
C. Campos ◽  
G. Oron ◽  
M. Salgot ◽  
L. Gillerman

A critical objective for any wastewater reuse programme is to minimise health and environmental hazard. When applying wastewater to soil–plant systems, it is to be noted that the passage of water through the soil considerably reduces the number of microorganisms carried by the reclaimed wastewater. Factors that affect survival include number and type of microorganisms, soil organic matter content, temperature, moisture, pH, rainfall, sunlight, protection provided by foliage and antagonism by soil microflora. The purpose of this work was to examine the behaviour of fecal pollution indicators in a soil irrigated with treated wastewater under onsurface and subsurface drip irrigation. The experiment was conducted in a vineyard located at a commercial farm near the City of Arad (Israel). Wastewater and soil samples were monitored during the irrigation period and examined for fecal coliforms, somatic and F+ coliphages and helminth eggs. Physico-chemical parameters were controlled in order to determine their relationship with removal of microorganisms. The results showed high reduction of the concentration of microorganisms when wastewater moves through the soil; and a good correlation between the reduction of fecal pollution indicators and moisture content, organic matter concentration and pH. The application of secondary treated domestic wastewater in this specific soil and under these irrigation systems affect the survival of microorganisms, thus reducing the health and environmental risk.


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