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NaOH precipitation applied to cheese whey wastewater (CWW) has been investigated in the pH range of 8.5–12.5. Optimum conditions were found at pH 11.0. High reductions of chemical oxygen demand—COD (40%), turbidity—T (91%), total suspended solids—TSS (69%), sulphates (93%), phosphorus (53%), total hardness (40%), calcium (50%), magnesium (27%), chlorides (12%), Kjeldahl nitrogen (23%), etc. were achieved. Treated CWW by the aforementioned process has been used for agricultural irrigation of two tomato cultivars (Roma and Rio Grande) after dilution with fresh water, which was used as control experiment (1.44 dS m−1). Five different irrigation treatments, with salinity level in the range of 1.75–10.02 dS m−1, were implemented with treated wastewater. Treatment did not show a significant effect on the total and marketable yield, production losses and tomato yield with physiological disorder of blossom-end rot. Nevertheless, the cultivar Rio Grande presented an increase up to 21% in the marketable yield, for salinity levels of 1.75–3.22 dS m−1, owing to an increment of the fruit fresh weight. Furthermore, treatment significantly influenced the tomato yield with epidermis deformations by solar exposure, unit fruit fresh weight and tomato number per kilogram. Fruit epidermis deformations due to solar exposition were minimized in about 27–93% when using treated wastewater. Raw sludge generated in the NaOH precipitation presented an average content of organic matter, phosphorus and nitrogen of (g kg−1 on a dry basis) 512, 5.8 and 11.2, respectively. Additionally, this sludge was treated by means of several processes. Centrifugation was quite efficient in the sludge volume reduction. The integrated sequence: aerobic digestion + sedimentation + centrifugation constituted a suitable treatment line, achieving a sludge volume reduction of 80% and simultaneously producing an effluent with organic matter depletion around 40%. Infiltrated water from sand filters was more contaminated organic and inorganically than the effluent obtained in the sequence: aerobic digestion + sedimentation + centrifugation.

The major and trace element component of 48 recent sediment samples in three distinct intervals (0–10, 10–20, and 20–30 cm) from Lake Acıgöl is described to present the current contamination levels and grift structure of detrital and evaporate mineral patterns of these sediments in this extreme saline environment. The spatial and vertical concentrations of major oxides were not uniform in the each subsurface interval. However, similar spatial distribution patterns were observed for some major element couples, due mainly to the detrital and evaporate origin of these elements. A sequential extraction procedure including five distinct steps was also performed to determine the different bonds of trace elements in the < 60-µ particulate size of recent sediments. Eleven trace elements (Ni, Fe, Cd, Pb, Cu, Zn, As, Co, Cr, Al and Mn) in nine surface and subsurface sediment samples were analyzed with chemical partitioning procedures to determine the trace element percentage loads in these different sequential extraction phases. The obtained accuracy values via comparison of the bulk trace metal loads with the total loads of five extraction steps were satisfying for the Ni, Fe, Cd, Zn, and Co. While, bulk analysis results of the Cu, Ni, and V elements have good correlation with total organic matter, organic fraction of sequential extraction characterized by Cu, As, Cd, and Pb. Shallow Lake Acıgöl sediment is characteristic with two different redox layer a) oxic upper level sediments, where trace metals are mobilized, b) reduced subsurface level, where the trace metals are precipitated. © 2018, Springer International Publishing AG, part of Springer Nature.

The OECD guidelines 308 and 309 define simulation tests aimed at assessing biotransformation of chemicals in water-sediment systems. They should serve the estimation of persistence indicators for hazard assessment and half-lives for exposure modeling. Although dissipation half-lives of the parent compound are directly extractable from OECD 308 data, they are system-specific and mix up phase transfer with biotransformation. In contrast, aerobic biotransformation half-lives should be easier to extract from OECD 309 experiments with suspended sediments. Therefore, there is scope for OECD 309 tests with suspended sediment to serve as a proxy for degradation in the aerobic phase of the more complicated OECD 308 test, but that correspondence has remained untested so far. Our aim was to find a way to extract biotransformation rate constants that are universally valid across variants of water-sediment systems and, hence, provide a more general description of the compound's behavior in the environment. We developed a unified model that was able to simulate four experimental types (two variants of OECD 308 and two variants of OECD 309) for three compounds by using a biomass corrected, generalized aerobic biotransformation parameter (k'bio). We used Bayesian calibration and uncertainty assessment to calibrate the models for individual experimental types separately and for combinations of experimental types. The results suggested that k'bio was a generally valid parameter for quantifying biotransformation across systems. However, its uncertainty remained significant when calibrated on individual systems alone. Using at least two different experimental types for the calibration of k'bio increased its robustness by clearly separating degradation from the phase-transfer processes taking place in the individual systems. Overall, k'bio has the potential to serve as a system-independent descriptor of aerobic biotransformation at the water-sediment interface that is equally and consistently applicable for both persistence and exposure assessment purposes.

Nematode density along a depth gradient (206-2760 m) in the northeastern Atlantic (Goban Spur) is linearly and positively related to organic matter mineralization in the sediment. It is estimated that nematodes contribute at most 13% to total carbon turnover, and this contribution decreases with water depth. The vertical distribution df nematodes in the sediment closely follows concentration vs depth profiles of total nitrogen in the sediment. Both nematodes and total nitrogen tend to be more concentrated towards the surface with increasing water depth. There is no indication that nematode vertical distribution is directly influenced by the oxygen penetration in the sediment. However, it is hypothesized that the sediment oxygen concentration dan explain the relatively greater importance of smaller organisms in benthic communities with increasing water depth. The nitrogen vs sediment depth profiles are consistent with a greater impact of larger organisms on sediments at the shallow stations and decreased sediment mixing with increasing water depth. [KEYWORDS: Deep-sea transect; vertical-distribution; organic-carbon; ne atlantic; metazoan meiofauna; marine-sediments; abyssal-plain;bottom water; shelf break; meiobenthos]