A hydrochemical study of the Hammam Righa geothermal waters in north-central Algeria

This study focuses on the hydrochemical characteristics of 47 water samples collected from thermal and cold springs that emerge from the Hammam Righa geothermal ?eld, located in north-central Algeria. The aquifer that feeds these springs is mainly situated in the deeply fractured Jurassic limestone and dolomite of the Zaccar Mount. Measured discharge temperatures of the cold waters range from 16.0 to 26.5 °C and the hot waters from 32.1 to 68.2 °C. All waters exhibited a near-neutral p H of 6.0–7.6. The thermal waters had a high total dissolved solids(TDS) content of up to 2527 mg/l, while the TDS for cold waters was 659.0–852.0 mg/l. Chemical analyses suggest that two main types of water exist: hot waters in the up?ow area of the Ca–Na–SO_4type(Hammam Righa) and cold waters in the recharge zone of the Ca–Na–HCO_3type(Zaccar Mount). Reservoir temperatures were estimated using silica geothermometers and?uid/mineral equilibria at 78, 92, and 95 °C for HR4, HR2,and HR1, respectively. Stable isotopic analyses of the δ^(18)O and δD composition of the waters suggest that the thermal waters of Hammam Righa are of meteoric origin. We conclude that meteoric recharge in?ltrates through the fractured dolomitic limestones of the Zaccar Mount and is conductively heated at a depth of 2.1–2.2 km. The hot waters then interact at depth with Triassic evaporites located in the hydrothermal conduit(fault), giving rise to the Ca–Na–SO_4water type. As they ascend to the surface,the thermal waters mix with shallower Mg-rich groundwater, resulting in waters that plot in the immature water?eld in the Na–K–Mg diagram. The mixing trend between cold groundwaters from the recharge zone area(Zaccar Mount) and hot waters in the up?ow area(Hammam Righa) is apparent via a chloride-enthalpy diagram that shows a mixing ratio of 22.6 \ R \ 29.2 %. We summarize these results with a geothermal conceptual model of the Hammam Righa geothermal ?eld.

Suitability of Groundwater from the Kherzet Youcef Lead-Zinc Deposit (North-Eastern Algeria) for Irrigation and Drinking Water Supply

As part of the hydro geological study of the Kherzet Youcef deposit, a drilling battery was carried out. The objective of this achievement is the satisfaction of the water needs of the city of Ain Azel (drinking water supply, irrigation and industrial water supply) and even the transfer to other municipalities suffering by the lack of water and the resumption of mining activity at the deposit of Kherzet Youcef. This water table is located in carbonate formations of Paleo-Neogene age linked to lead-zinc mineralization. Knowledge of water quality and its suitability for human consumption is an obligation. These metals have adverse health effects. We used the results of Sonarem’s analyses from 1973 to 1979. In addition, we carried out two analyses, during two years 2015-2016, on five boreholes. The parameters analyzed are major elements, physical parameters and trace metal elements (Zn, Pb and Fe). The analyses were done by ICP-AES. In our work, it has been shown that waste water is suitable for use in agriculture. For this we used the electrical conductivity at 25°C and those of the sodium adsorption ratio (SAR). For drinking water supply, monitoring the change in trace metal element (Zn, Pb and Fe) for two years has allowed us to conclude that groundwater in the groundwater table east of the Kherzet Youcef fault is generally acceptable. They are eligible by the quality standard set by Algerian regulations. However, they exceed the world health organization (WHO) standards, especially for lead. We recommend a revision of drinking water quality standards set by Algerian regulations, rigorous monitoring of TME content variation and water treatment before distribution.