Coagulation is often used for the pre-treatment of industry wastewater, with effectiveness strictly dependent on technological conditions. This study aimed at determining what technological parameters of coagulation of cosmetic industry wastewater provide the highest efficiency of clarification. The dosages of reagents, the order of dosing, as well as the one-and two-stage processes were investigated. The samples of raw wastewater were collected from average daily effluent from a cosmetics manufacturing plant. Liquid coagulant PIX 111 (FeCl 3 ) and NaOH as a pH-adjusting agent were used. Jar-test experiments were carried out to determine the optimum conditions for turbidity and total organic carbon (TOC) removal. The efficiency of clarification was high (90-99%) across a wide range of pH values (6-9) and coagulant doses (0.5-1.25 mL/L). What is important is that the coagulant dose of 0.56 mL/L provided 97.6% clarification efficiency without the addition of the alkali. The minimal stoichiometric excess of alkalinity for effective coagulation was 0.5 mmol/L. In all samples, the removal efficiency for TOC was lower than for turbidity, because some of the organic carbon forms were non-coagulating dissolved compounds. The wastewater from tonic and fluid production was very susceptible to coagulation. The addition of the coagulant before the alkali resulted in better wastewater treatment efficiency than the reverse order. Single-stage process with optimal doses of the reagents allowed to clarify wastewater to a level of 10 NTU. On the other hand, the two-stage process brought the turbidity down to 1 NTU level.

This paper reports the results of determinations of crystalline phase type, specific surface area, point of zero charge pH (pHpzc), and Ni(II) sorption capacities of beds for groundwater treatment. Bed materials from iron and manganese removal filters (FeRF, MnRF) as well as a catalytic bed (G1) were investigated. The reference material was MnO2-coated quartz sand (MnQS). The efficiency of Ni(II) sorption was investigated as a function of pH. It was found that the naturally formed coating on FeRF was characterised by the highest sorption efficiency (80–88%) in the wide pH range (4–9) of the solution. Sorption on MnRF was weaker (35–45%). G1 and MnQS, which contained only manganese oxides, were characterised by a very low sorption efficiency of 0–6% and 3–8%, respectively. A lower Ni(II) removal efficiency was observed at an initial pH close to the pHpzc values. During Ni(II) sorption, the pH of the solution was not constant and tended towards the value of pHpzc for all tested materials. The slightly pH-dependent sorption of Ni(II) indicates that its removal depends more on the chemical composition and the specific surface area of the oxide coatings covering the bed materials.

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The aim of the study was to assess the usefulness of fly ashes produced by co-combustion of hard coal with biomass (WB1, WB2) and biomass combustion (B) in the adsorption process of lead(II) ions. Adsorption isotherms of Pb(II) ions was determined. The analysis of the results was based on equilibrium adsorption models. Langmuir, Freundlich as well as Redlich-Peterson and Langmuir-Freundlich models were used. Langmuir and Freundlich models were analyzed in both general and linear forms. Experimental data were best described by Langmuir equation in linear form (r 2 > 0.9). Comparison of the three ashes showed that the lowest sorption capacity was obtained for that from the green block (15.3 mg/g), significantly higher for both from co-combustion (34.8 mg/g for WB1, 29.9 mg/g for WB2). Analysis of the chemical composition of the surface confirmed the determined sorption capacity with respect to lead. The ashes were characterized by alkaline properties.Keywords: fly ash, biomass, co-combustion, adsorption, Pb(II) ions WstępMetale ciężkie zawarte w ściekach przemysłowych są istotnym źródłem zanieczyszczenia środowiska. Główne ich źródła to przede wszystkim górnictwo i przemysł metalurgiczny. Usuwanie metali ciężkich z wód ściekowych jest bardzo ważnym zagadnieniem ze względu na ich toksyczność -szkodliwe oddziaływanie na organizmy żywe. Przeciwdziałanie ich przedostawaniu się do środowiska wodno-glebowego realizowane jest z wykorzystaniem różnych metod. Zaliczają się do nich procesy adsorpcyjne prowadzone z użyciem różnych adsorbentów. Do najbardziej skutecznych należą węgle aktywne. Ze względu na ich cenę wciąż poszukuje się tańszych