Characteristics and quality of gray water and the possibility of reuse for irrigation purposes from the houses of some areas of the left side of the city of Mosul

The research dealt with assessing the quality of gray water generated from houses in some areas of the left side of the city of Mosul and determining the suitability of reusing it for irrigation; for this purpose, 90 samples of gray water were collected from fifteen neighborhoods of the left side for a period of six months during the period from November 2020 to April 2021. The research aims to conduct a monthly study to assess the quality and suitability of gray water for irrigation by conducting physical, chemical, and biological tests for gray water generated from houses Where the values of E.C. ranged (751-1621) μS/cm and T.D.S. (483-684) mg/L, and pH ranged (6.3-8.2), and the concentration of sodium ions ranged between (7.8-147) mg/L as for the concentration of C.O.D. (Chemical Oxygen Demand) ranged between (69-200) mg/L While the C.O.D. values ranged between (69-200) mg /L , The S.A.R. values were between (0.18-2.98) meq/L, and the phosphate ions values ranged between (0.25-3.7) mg/L; finally, the average of fecal coliform bacteria was (0.0-4) x 105/100 ml. The study concluded that the water was classified under the category (C3-S1) high salinity - low sodium, which is suitable for irrigation of plants that are well tolerant to salinity and is suitable for use in soils that do not contain complex layers that prevent leaching because these soils will need to be washed when irrigated with this water. This study recommended diluting gray water by mixing it with fresh water and using it for irrigation.

Reduction of Gray Water and Run-off in a Residential Environment with Rain Garden Model (Case Study “Settlements in Makassar City”)

Residential neighborhoods produce wastewater originating from soapy water, oil, and similar wastes which are included in the gray water category, as well as rainwater runoff from tiles and those that fall in the house, so the best way to consider is to install a water treatment system. integrated waste. The purpose of this study is to identify a Rain Garden model that is suitable for application in the residential areas of Makassar City. The method used is by identifying the suitability of the Rain Garden land, calculating the dimensions, and making the right Rain Garden model. From the results of the study it was concluded that the Rain Garden model for the reduction of gray water and rainwater runoff in the Makassar City residential environment was designed to have three cropping variations. Time to fill RG with the design of the design of Gray Water discharge reservoir and runoff discharge based on water loss in the residential environment. With a flow rate of V = 0.3 m3 / s, the depth of flow Y = l.2 m. Based on the relationship between the width and depth of flow at the best hydraulic section in rectangular shape, the channel bottom is B = 0.8 m, guard height (F) 30% Y=0.36 m. The effectiveness of household waste treatment and rainwater runoff using this Rain Garden model, for BOD = 102.8 mg / L (inlet) to 8.4 mg / L (outlet). The highest TSS value was 79 mg / L (inlet) to 8.3 mg / L (outlet). The highest detergent value was 59.84 mg / L (inlet) and showed the yield after processing was 1.25 mg / L (outlet). Treatment of gray water and rainwater runoff in residential environments is to reduce the volume of liquid waste that enters the city drainage system and create a sustainable urban sanitation ecology.

Water footprint in family farming

Currently, the management of water resources has gained greater visibility and has become indispensable, with the need for different methodologies which consider all water used and incorporated in the processes and products. In this way, the water footprint concept has been introduced to calculate the appropriation of fresh water on the part of the humankind. Thus, the objective of this work was to determine the water footprint in some sectors of family farming in the municipality of Teófilo Otoni – MG, analyzing the agricultural production of crops cultivated exclusively by the sector in 2017 in Teófilo Otoni. The cultivation of pumpkin, banana, chayote, beans, cassava, Maize, peppers, okra, cabbage, and tangerine were studied. Thus, the total water footprint for the year 2017 was 13,996,735.05 m3.t-1, in which the green water footprint represents 86%, the blue water footprint represents 12.5% and the gray water footprint equals 1.5%. The family farming sector of Teófilo Otoni demands an average of 196.73 liters for a production of R$ 1.00.

Gray water treatment by air-gap multi-effect membrane distillation with pre-treatment by electrocoagulation

The gap between supply and demand of fresh water is widening due to increase in global population. Hence, an alternative source of water such as gray water could potentially save significant amount of precious fresh water. Gray water is distinct from black water by amount and composition of its chemical and biological contaminants. In this paper, an air-gap Multi-effect membrane distillation (MEMD) module performance for gray water treatment is described. Surfactant present in the gray water was wetting membrane pores. Hence, electrocoagulation was used as a pre-treatment of gray water feed. About 99.14% surfactants were removed by electrocoagulation and the experiment shows excellent performance of the MEMD module. The 4-stage MEMD module offered permeate fluxes nearly to 50.12 l/m2 h at 80 °C. It was also found that a high thermal efficiency and output gain ratio was possible with lower specific energy and no cooling water. Hence, it is apparent that the air gap MEMD technology could be used for gray water treatment. Pre-treatment by electrocoagulation (EC) operation seems an important step in the overall treatment process when large amount of surfactants are present in the treatment water.