Evaluation of Tannery Wastewater Treatment by Integrating Vesicular Basalt With Local Plant Species in a Constructed Wetland System

Tannery wastewater is composed of a complex mixture of organic and inorganic components from various processes that can critically pollute the environment, especially water bodies if discharged without treatment. In this study, integrated vesicular basalt rock and local plant species were used to establish a horizontal subsurface flow constructed wetland system and to investigate the treatment efficiency of tannery wastewater. Four pilot units were vegetated with P. purpureum, T. domingensis, C. latifolius, and E. pyramidalis, and a fifth unit was left unvegetated (control). The constructed wetland units in horizontal subsurface flow systems were effective in removing total chromium (Cr), chemical oxygen demand (COD), and 5-day biological oxygen demand (BOD5) from the inflow tannery wastewater. The removal efficiency reached up to 99.38, 84.03, and 80.32% for total Cr, COD, and BOD5, respectively, in 6 days of hydraulic retention time (HRT). The removal efficiency of total suspended solid (TSS), total phosphorus (TP), and nitrate (NO3−) of the constructed wetland units reached a maximum of 70.59, 62.32, and 71.23%, respectively. This integrated system was effective for treating tannery wastewater, which is below the Ethiopian surface water standard discharge limit set to BOD5 (200 mg L−1), COD (500 mg L−1), total Cr (2 mg L−1), NO3− (20 mg L−1), TSS (50 mg L−1), and TP (10 mg L−1).

Calcite U-Pb dating of altered ancient oceanic crust in the North Pamir, Central Asia

The North Pamir, part of the western syntax of the India-Asia collision zone, preserves remnants of a poorly investigated Paleozoic intra-oceanic subduction zone. To constrain the age of this ancient ocean floor, we analyzed calcite phases in vesicular basalt and basaltic volcanic breccia with U-Pb geochronology using laser-ablation inductively-coupled-plasma mass-spectrometry (LA-ICP-MS). Calcite dating yielded Mississippian ages, mostly overlapping each other within errors. REE + Y data reveal that the basaltic host rock of the calcite and oxidizing seawater are major sources of trace elements during calcite precipitation. U-Pb ages seem to be independent of REE + Y concentrations. Our results demonstrate the potential of calcite dating to constrain the age of ancient ocean floors and provide a test of the hypothesis that a continuous early Paleozoic Kunlun Terrane extended from northern Tibet into the North Pamir.

Development of Self-Cured Sustainable Concrete Using Local Water-Entrainment Aggregates of Vesicular Basalt

The environmental and economic concerns pertaining to the construction industry have necessitated the development of sustainable concrete. Durability and strength are the two primary properties which determine the sustainability of concrete. This study evaluated the performance of self-cured concrete produced from local vesicular basalt porous aggregates. The durability indicators, porosity, permeability and pore size of the hardened concrete, were obtained from the water sorptivity (water permeability under capillary action) test, the water permeability under pressure action test and the Brunauer–Emmett–Teller (BET) surface area test and strength was evaluated in terms of compressive strength of concrete. The concrete specimens were produced with 10% porous vesicular basalt aggregate in replacement of coarse aggregate. The concrete specimens were tested at 3, 7 and 28 days. The self-curing effect on concrete strength was evaluated against water, air and membrane cured specimens, at surface/volume ratio of 26.4/40 and w/c ratio of 0.35/0.5. A 20% decrease in sorptivity coefficient, 10% increase in solid surface area and about 10% increase in compressive strength of the self-cured concrete was observed over the conventionally cured concrete. The study concludes that the addition of water-entrainment aggregates to concrete reduces water permeability, results in a finer pore structure of concrete and increases the quality and durability of concrete.

Mineralogy and Chemical Composition of Basalt Stone Tools in Some Iraqi Archaeological Sites

Basalt stone tools were collected from some Iraqi Archaeological Sites. Twenty-one samples were studied petrographically, mineralogically, and chemical composition. Five samples were from the Gaara Depression north of Rutba town, seven samples from Tarmiya, north Baghdad, seven samples from Dalmij site, east of Diwaniya city, and two samples from Jordan, which were used for comparison. The studied samples were classified into three groups, according to their mineralogy and texture: Group A: Vesicular Basalt, Group B: Dolerite, and Group C: Olivine Basalt. These stones most probably were used as a hand axe, grinder, hammer, and other uses, as well as for buildings, like those used in Qasar Al- Azraq and Umm Al- Jamal archaeological sites in Jordan. These basalt rocks most probably were transported by an ancient man from Harrat Al-Sham, which extends through Syria-Jordan-Saudi Arabia, or from NE Syria through a trade route that connected between source areas and the studied archaeological sites in Iraq.