The mechanisms by which complex products released from the organic matrix of cattle manure impact phosphorus (P) behavior and transport are largely undefined. Effects of a dairy slurry isolate on sorption characteristics of three benchmark soils and the breakthrough of phytate-P were determined in short soil columns of Mattapex loam (fine-silty, mixed, active, mesic Aquic Hapludults) under saturated flow conditions. The manure liquid isolate was obtained after a 7-day incubation of reconstituted dairy manure (1.6:1, feces-to-urine) at 37 °C and centrifugation at 16,000×g. The liquid isolate, at dilutions of 20:1 to 4:1 water-to-isolate, decreased soil sorption of phytate-P, with reduction in logₑ K averaging 30%. Whether the influent contained artificial rainwater or the manure isolate at a water-to-isolate ratio of 20:1, P retention and breakthrough curves were differentially impacted. Only inorganic phosphate-P was eluted in a multiple-stage process, and breakthrough occurred after 16 pore volumes of rainwater. Both inorganic- and enzyme-labile P (TBIOP) appeared in the effluent when either a dilute solution of 0.05 M EDTA (ethylenediamine-N, N, N′, N′-tetraacetate) or one containing 5% of manure liquid isolate was used as influent. The polydentate ligand-like substances reduced (i) the soil’s affinity for phytate and (ii) the hydrolysis rate in soil, allowing phytate to be eluted. Therefore, dissolved components of the manure matrix played critical roles in controlling transport and dispersion of phytate-derived P forms in soil and may hold the key to the understanding of biogeochemical bases of persistent effects of legacy P in agricultural watersheds.

Dynamics of chemical characteristics and hygienic quality, particularly nutrients, heavy metals, and bacterial pathogens, were investigated along the storage of anaerobically digested slurry derived from chicken and pig manure. The average total solid (TS) content decreased by 3.6 and 24.1%, while soluble chemical oxygen demand (SCOD) decreased by 23.7 and 31.4%, in chicken manure- and pig manure-digested slurries storage, respectively. A rapid increase in NH₄ ⁺-N concentration from 1600 to 4800 mg/L in chicken manure-digested slurry and from 1200 to 1700 mg/L in pig manure-digested slurry was noted, particularly during the first 10 days of storage. A positive correlation between TS and content of heavy metals (Cu, Zn, Cr, and Pb) in the digested slurry was clearly shown. These metals are mainly associated with suspended particles and tend to be settled in the bottom during the storage process. Increasing attention should be paid to the land application of these bottom-settled digestates with higher TS content. The number of total coliforms and Escherichia coli in the both digested slurries decreased continuously during the whole storage period. The higher reduction rate observed during the storage of chicken manure-digested slurry may be due to the higher content of NH₄ ⁺-N, which may cause the inhibition of gram-negative bacteria. The results of this study provides a better understanding of the storage process of anaerobically digested slurry, which could benefit the digested slurry further utilization as agriculture fertilizer.

Activated carbon has widespread application in antibiotic-loaded wastewater treatment in recent years, owing to its developed pore structure, high superficies reactivity, and excellent mechanical and chemical stability. In this work, sorption experiments of four representative antibiotics, including sulfadiazine (SDZ), norfloxacin (NOR), metronidazole (MDE), and tetracycline (TC), over granular activated carbon (GAC), which was made from maize straw, were firstly studied. Kinetics, mechanism, and isotherm models related to the sorption process were employed. Results revealed that the sorption capacity by GAC followed the order SDZ > NOR > MDE > TC. The sorption kinetics of the four antibiotics well conformed to the pseudo-second-order model. Both the Weber-Morris intraparticle diffusion and Boyd kinetic models conveyed the information that film diffusion was dominant in the sorption process. The sorption isotherm was better fitted to the Langmuir model. This research may pave a basic way for removing antibiotics in municipal and industrial wastewater by activated carbon.

Phytoremediation using vetiver grass (Vetiveria zizanioides) has been regarded as an effective technique for removing contaminants in polluted water. This study was conducted to assess the removal efficiency of heavy metals (Cu, Fe, Mn, Pb, Zn) using vetiver grass (VG) at different root lengths and densities and to determine metals uptake rate by plant parts (root and shoot) between treatments (low and high concentration). Removal efficiency for heavy metals in water by VG is ranked in the order of Fe>Pb>Cu>Mn>Zn. Results showed that VG was effective in removing all the heavy metals, but removals greatly depend on root length, plant density and metal concentration. Longer root length and higher density showed greater removals of heavy metals due to increased surface area for metal absorption by plant roots. Results also demonstrated significant difference of heavy metals uptake in plant parts at different concentrations indicating that root has high tolerance towards elevated concentration of heavy metals. However, the effects were less significant in plant shoot suggesting that metals uptake were generally higher in root than in shoot. The findings have shown potential of VG in phytoremediation for heavy metals removal in water thus providing significant implication for treatment of metal-contaminated water.

The setting-up of anammox granules reactor is time-consuming and highly sensitive to the environment. Metal ions were reported to facilitate granulation; however, there is no report of a practical guide to metal ion application in anammox, especially relative to the effects of different ions at different concentrations on granulation. Adding recycle to reactors is important in treating industrial wastewater with high levels of NH₄ ⁺-N, but the optimum recycle ratio is still unclear. This study investigated the effect of Ca, Mg, Fe ions, their concentration, and recycle ratio of an upflow anaerobic sludge blanket reactor on anammox granulation as well as on reactor performance. The main physical properties of granules tested were sludge granulation rate, settling velocity, mixed liquor suspended solids (MLSS), mixed liquor volatile suspended solids/MLSS, and specific anammox activity (SAA)/nitrogen removal rate. The results demonstrated that introducing cations into cultivating mediums accelerates the anaerobic granulation process and improves specific anammox activity. In particular, Mg and Fe runs reached maximum SAAs with concentrations of 0.06 mmol/L and improved by ~ 25% of SAA compared with the control. SAAs of Ca runs were lower than those of Mg and Fe runs and showed a peak at a concentration of 0.03 mmol/L. In addition, recirculation enhanced the granulation. Granulation and retention of the anammox biomass were benefitted most when the recycle flow added was equal to the influent injection (noted as Q). Nitrogen removal also reached a maximum at Q, with removal efficiency of 97.3% with NH₄ ⁺-N and 98% with NO₂ ⁻-N. Thus, appropriately adding metal ions and recycle flow helped achieve quick setting-up and better performance. We also considered the relationship between four properties of granules tested and the performance of the reactor.

The effect of different Cr and Zn concentrations in the soil on the development of Albares wheat and Pedrezuela barley plants at the physiological, biochemical, and structural levels was evaluated during the crop cycle in a greenhouse assay, as well as their potential use in phytoremediation strategies. The accumulation of Cr and Zn in plants was dose-dependent for both cultivars. The highest contents were found in root and the lowest in grain. In the Cr treatments, the decrease with respect to the control in the biomass, relative water content (RWC), chlorophyll content (Chl), and chlorophyll fluorescence values (Fv/Fm) was more pronounced in wheat than in barley. For the Zn treatments, the behavior was the opposite. Barley showed less tolerance to Zn concentrations although its higher translocation factor (TF) and greater biomass make this plant adequate to use in phytoremediation process in soil contaminated with Zn. The electron microscopy studies showed evidence that treatment with both Cr and Zn produced alterations in the cellular ultrastructure of the plant leaves. Cr and Zn induced the production of malondialdehyde (MDA) in both cultivars; the highest concentrations were observed in barley leaves. In general, the ascorbate peroxidase activity (APX) was higher in the plants exposed to metal treatments. The catalase activity (CAT) showed a different behavior depending on the metal studied. These results highlight the potential capacity of Albares wheat for use in the phytoremediation of soils contaminated by Zn and of Pedrezuela barley for use in Cr- and Zn-contaminated soils.

Microbial fuel cell (MFC) is a sustainable technology to treat cattle manure slurry (CMS) for converting chemical energy to bioelectricity. In this work, two types of allochthonous inoculum including activated sludge (AS) and domestic sewage (DS) were added into the MFC systems to enhance anode biofilm formation and electricity generation. Results indicated that MFCs (AS + CMS) obtained the maximum electricity output with voltage approaching 577 ± 7 mV (~ 196 h), followed by MFCs (DS + CMS) (520 ± 21 mV, ~ 236 h) and then MFCs with autochthonous inoculum (429 ± 62 mV, ~ 263.5 h). Though the raw cattle manure slurry (RCMS) could facilitate electricity production in MFCs, the addition of allochthonous inoculum (AS/DS) significantly reduced the startup time and enhanced the output voltage. Moreover, the maximum power (1.259 ± 0.015 W/m²) and the highest COD removal (84.72 ± 0.48%) were obtained in MFCs (AS + CMS). With regard to microbial community, Illumina HiSeq of the 16S rRNA gene was employed in this work and the exoelectrogens (Geobacter and Shewanella) were identified as the dominant members on all anode biofilms in MFCs. For anode microbial diversity, the MFCs (AS + CMS) outperformed MFCs (DS + CMS) and MFCs (RCMS), allowing the occurrence of the fermentative (e.g., Bacteroides) and nitrogen fixation bacteria (e.g., Azoarcus and Sterolibacterium) which enabled the efficient degradation of the slurry. This study provided a feasible strategy to analyze the anode biofilm formation by adding allochthonous inoculum and some implications for quick startup of MFC reactors for CMS treatment.

Electrokinetics (EK) was investigated as a possible technique for in-situ treatment of leachable chromium at a built site contaminated with chromium ore processing residues (COPR). A preliminary EK experiment was carried out at the laboratory scale on an undisturbed COPR core sample. Methods applied for material and pore water characterization before and after EK treatment addressed physical aspects by laser diffraction granulometry, pycnometry and pore water content, mineralogical aspects by X-ray diffraction, scanning electron microscopy coupled with energy dispersive X-ray spectroscopy, and chemical aspects by inductively coupled plasma-atomic emission spectroscopy and atomic absorption spectroscopy for elemental composition, spectrophotometry for Cr(VI) analysis, and potentiometry for pH determination. EK was run at 1 V/cm with no external constraints on current intensity. The EK experiment reached an extraction of 72% of the total leachable Cr(VI) after only 10 days of treatment and 84% after 20 days. Material texture, composition, and pH remained similar. These results indicate that EK presents a potential solution for extracting leachable Cr(VI) from COPR sites. The impounded COPR material appeared to be heterogeneous in composition at all scales, from field to lab sample, adding to the challenge of in-situ treatment.

A novel cement-polyurethane hybrid material invented to stop massive water ingress during e.g. tunnel construction is presented in this study. A special emphasis is put on the leaching behaviour and the environmental impact of the material. For this purpose, a batch test as worst-case scenario and a tank leaching test were used to compare different material combinations. Besides sum parameters like pH value, major elements from cement and organic species were analysed in the leachates. Simulations about the release behaviour of ionic species as well as the total organic carbon were performed. Release was governed by surface wash-off effects for all species except for Al which was controlled by diffusion. Leaching of major elements correlated with the amount of ground granulated blast furnace slag added to substitute ordinary Portland cement. Total organic carbon content was measured, and the cumulative value was in the range of 83 to 49 mmol/m² after 64 days of leaching. All investigated parameters were below the threshold values governed by German authorities. In addition, ecotoxicological tests with earthworm species (Enchytraeus albidus) have been performed to explore the impact of the leachates on the environment. While in pure eluate tests the early age leachates showed toxic effects, in soil and sand tests the buffering function plays a key role to prevent possible hazardous effects.

Biochars, derived from rambutan (Nepheliumlappaceum) peel through slow pyrolysis, were characterised and investigated as potential adsorbent for the removal of copper ion, Cu(II) from aqueous solution. Characteristics of five biochars of rambutan peel with different pyrolytic temperatures ranging from 300 to 700 °C (B300, B400, B500, B600, B700) were studied, and adsorption abilities of respective biochars were evaluated. Adsorption experiments were carried out by varying adsorbent dosage (0.2, 0.4, 0.8, 1.0, 2.0, and 4.0 g/L) and initial copper ion, Cu(II) concentrations (50 and 100 mg/L) to determine the optimum pyrolytic temperature of biochar with high adsorption affinity. The adsorption kinetics were best described by the pseudo-second order model for all the tested biochars, while the adsorption equilibrium best fitted by Langmuir isotherm. The overall results showed that biochar derived at 600 °C can be used as an effective adsorbent for removal of Cu(II) from aqueous solutions. Furthermore, feedforward artificial neural network (FFBP) modelling was performed to compare the simulated results with experimental output data of Thermogravimetric analysis (TGA) and atomic absorption spectroscopy (AAS) analysis which were trained using Levenberg-Marquardt (LM) backpropagation algorithm. The FFBP structure for pyrolysis process comprised of TGA temperature as input and biomass final weight as output. The adsorption modelling was simulated using adsorption time, temperature, biochar dosage and initial Cu(II) concentration as input data, while final Cu(II) concentration was used as output data to the network. Finally, modelling structure of 1-9-1 and 4-8-1 gave best performance with regression, R ² value of 0.9999 and 0.9547 for TGA and AAS analysis, respectively.