Application of Moringa Oleifera seed extract to treat coffee fermentation wastewater.

Wastewater generated from wet processing of coffee cherries degrades stream water quality downstream of processing mills and impacts human health. The widespread popularity of coffee as an export makes this a global problem, although the immediate impact is local. Approximately 40% of all coffee around the world is wet processed, producing wastewater rich in organic nutrients that can be hazardous to aquatic systems.

Identification of chlorinated oligomers formed during anodic oxidation of phenol in the presence of chloride.

Chlorinated oligomer intermediates formed during the anodic electrochemical oxidation of phenol with a boron-doped diamond electrode were studied at two different concentrations of chloride (5mM and 50mM). Under the same ionic strength, with sodium sulfate being the make-up ion, a 10-fold increase in Cl(-) led to removal rates 10.8, 1.

Effects of oligomerization phenomenon on dissolved organic matter removal kinetics on novel activated carbons.

The overall objective of this research was to determine the effects of oxidative coupling (oligomerization) phenomenon on the adsorption kinetics of dissolved natural organic matter (DOM) on novel tailored activated carbons. A comparison of adsorption kinetics data collected in the presence and absence of phenolic compounds under both oxic (presence of molecular oxygen) and anoxic (absence of molecular oxygen) conditions showed that the adsorption rate of DOM was strongly affected by the oligomerization phenomenon. The diffusion rate of DOM is in inverse proportion to the critical oxidation potential of the phenolic compound.

Elucidating the role of phenolic compounds in the effectiveness of DOM adsorption on novel tailored activated carbon.

Two novel tailored activated carbons (BC-41-OG and BC-41-MnN) with favorable physicochemical characteristics were successfully prepared for adsorption of dissolved natural organic matter (DOM) by applying systematically chemical and thermal treatment. This research was conducted to investigate the impact of the presence of phenolics on the adsorption capacity of DOM. Isotherm tests were performed for both humic acid (HA) and phenolics on both novel tailored activated carbons and commercial activated carbon F400.

Using toxicity testing to evaluate electrochemical reactor operations.

In the present study, the Microtox® test was used to track the toxicity of electrochemical effluents to the marine bacteria Vibrio fischeri as a function of reaction time. When electrochemistry was used to degrade aqueous phenol using different reactor configurations, two reaction pathways were identified, chlorine substitution and oxidation, depending on whether the electrolyte contained chloride. For a boron-doped diamond (BDD) anode, electrochemistry using Na₂SO₄ electrolyte produced a significantly more toxic effluent than when using NaCl electrolyte with all other conditions remaining the same.

Evaluation of surface sampling techniques for collection of Bacillus spores on common drinking water pipe materials.

Drinking water utilities may face biological contamination of the distribution system from a natural incident or deliberate contamination. Determining the extent of contamination or the efficacy of decontamination is a challenge, because it may require sampling of the wetted surfaces of distribution infrastructure. This study evaluated two sampling techniques that utilities might use to sample exhumed pipe sections.

Comparing the solid phase and saline extract Microtox assays for two polycyclic aromatic hydrocarbon-contaminated soils.

The performance of remedial treatments is typically evaluated by measuring the concentration of specific chemicals. By adding toxicity bioassays to treatment evaluations, a fuller understanding of treatment performance is obtained. The solid phase Microtox assay is a useful tool in characterizing the toxicity of contaminated soils and sediments.