Impact of groundwater discharges on marine water quality in Doha, Qatar

Qatar is classified, according to its geographical location and climate, as a hot subtropical desert. Qatar's average annual rainfall is less than 130 mm/year [5 in]. Doha, the capital of State of Qatar, is served by a collection system of groundwater and storm water which finally is disposed off into the marine water through three outfalls. In the future, another four proposed outfalls will be operating. This study aimed at assessing the impact of groundwater discharge on the receiving marine water quality. Water Samples were collected from the outfalls it themselves, Sea water from different sites around these outfalls at different distances, sea water Samples from different sites around the proposed points at different distances, and offshore samples Es reference. Samples were collected during year 2007 and were analyzed physicochemically and microbiologically. Physicochemical characterization of the discharges showed that all measured parameters were complied with the environmental limits of both Qatar and GCC laws except turbidity and total suspended solids. The values of total and fecal coliform were higher than the permissible limits for Qatar and GCC environmental laws. The Physico-chemical characterization of the sea water samples collected from different sites around the discharged points recorded higher total suspended solids than the permissible limits stated by the Qatari law while the other parameters were complying with the law. Total suspended solids were higher than the permissible limits in all marine water samples while samples around the discharges points were the highest. The excees of some parameters reported by the study is due to the state urbanization and constructions activities in general. An integrated management plan must be carried out by all governmental and non-governmental authorities to protect the groundwater and avoid the deterioration of marine water quality

Assessment of the quality of treated sewage sludge [Doha, Qatar]

This study aims at evaluating the quality of currently produced sewage sludge in Doha, State of Qatar. Doha urban areas are currently served by two tertiary wastewater treatment plants at Al-Neaaga [Doha south plant] and Al-Sailiyah [Doha west plant]. Industrial areas around Doha are getting wastewater treatment facilities where extra amounts of sludge will be generated. Sludge is composed of primary and secondary sludge and sedimented sand filters backwash. It undergoes further treatment by drying beds for Doha south plant and centrifugation for Doha west plant. Doha south plant produced 190 m[3]/d sludge, Doha west plant produced 110 m[3]/d sludge, and industrial region plant produced 16 m[3]/d sludge. Samples were collected weekly for two months before and after drying beds from Doha south plant, after centrifuge and after storage from Doha west plant, and from industrial region plant. Samples were analyzed chemically and microbiologically. The results revealed that sludge produced by the three plants had heavy metals concentration way below the EBA ceiling limits for land application. On the other hand, the microbiological characterization of the product classified it as class B sludge according to EBA classification which requires significantly reduction of pathogen. Ascaris lombricoides and Toxocara cati were the most dominant ova detected. The sludge produced needs monitoring and further treatment before its application on land