No abstract

Removal of nickel ions from aqueous solutions containing 1-100 mg l(-1), using pine tree (Pinus nigra) materials modified with HCl, was investigated on a laboratory scale. For this purpose, two natural adsorbents such as the modified pine bark (MPB) and the modified pine cone (MPC) materials with HCl solution were studied. At first, the required concentration level of the HCl solution for the modification was observed, and then this was followed by the determinations of optimum levels of adsorbent amount, stirring rate, contact time and pH values. Various adsorption isotherms were also obtained by using different concentrations of the heavy metal cations tested in the experiment. As a result, the maximum removal efficiency levels obtained were as follows; 97% for the modified pine bark at pH 8 and 80% for the modified pine cone at pH 8.

Chromium (VI) is one of the heavy metals in water and wastewater that has the most toxic characteristic. Consequently, it is dangerous for human and environmental health. Various methods are used for removal of the chromium from wastewater, and new methods have been developed in recent years. Recent studies and investigations on the removal of environmental pollution selected methods that were economical, of optimum efficiently and could be carried out easily. In this study, the removal of Cr6+ in the leather industry wastewater is investigated using MnSO4 that was used easily and economically. Experimental studies are performed in two phases. In the first phase, the optimum MnSO4 dose for removal of Cr6+ was determined. In the second phase, the optimum pH was studied. About 96% removal of chromium was launched with 530 mg l(-1) MnSO4 dose at pH value 9 in the wastewater sample.

The Ministry of Environment and Urbanization (MoEU) initiated an important project, ‘Reuse of Treated Wastewater in Turkey’, in 2017. With this project, all wastewater treatment plants (WWTPs) were investigated to determine wastewater reuse purposes for the first time. The results obtained from this project were that although there are 1,015 existing WWTPs, only 15 of them realized wastewater reuse. In 2017, the total volume of reused treated wastewater in Turkey amounted to 29.6 million m3/year, accounting for 0.78% of the treated urban wastewater. With the present water potential and sectoral water use rates, Turkey should make key administrative and technical regulations in the coming years for water reuse. This paper aims to give an overview of wastewater reuse activities from present status to future potential in Turkey and the opportunities and challenges in expanding water reuse. The status of WWTPs, treatment processes and their compliance with the WWTPs where reuse is carried out in Turkey are evaluated in this study. The realization of the planned goals and challenges are discussed after regulatory changes in Turkey for reclaimed wastewater and reuse targets for 2023.