In an effort to customize biochars for soil amendments, multiple feedstocks have been combined in various ratios prior to pyrolysis. The resulting variation in the chemistry and structure can affect a biochar’s adsorption capacity, which influences the bioavailability of many chemical compounds in the soil system including phenolic acids. This study characterizes the sorption of 14C-labeled ferulic acid, syringic acid, and chlorocatechol to four biochars prepared from individual feedstocks and four from mixed feedstocks using batch equilibration. Pure feedstock biochar sorption followed switchgrass< swine solids< poultry litter< pine chip for both ferulic (Kd= 1.4-75) and syringic acid (Kd= 0.07-6.03), and appeared to be influenced by the properties of the biochars as well as the chemicals themselves. All biochar Kd values, except pine chip, were lower than that of the reference soil (Waukegan silt loam). The sorptive properties of the combined feedstock biochars could not be predicted from their pure feedstock components and sorption coefficients were both unexpectedly higher and lower than the individual parent materials’ biochars. Further research is necessary to understand the characteristics of these combination biochars, particularly their sorption, which this study has shown is not merely an intermediary of its components.

This is the first study that investigates in detail the effect of different sulfate concentrations on trichloroethene-dechlorinating microbial communities, both in terms of dechlorinating performance and microbial composition. The study used a series of Dehalococcoides-containing trichloroethene-dechlorinating microbial communities, which operated for more than 800 days in the presence of different sulfate concentrations and limiting-electron donor conditions. This study proves the ability of Dehalococcoides spp., the only genus able to completely dechlorinate trichloroethene, to predominate in mixed anaerobic microbial communities regardless of the magnitude of sulfate concentration, even under limiting-electron donor conditions. Although other microorganisms, such as the Sulfurospirillum spp. bacteria and members of the sulfate-reducing bacteria group were able to thrive, they were not able to predominate in such a competitive environment. However, this picture was not reflected in reductive dechlorination, which demonstrated a much better performance under methanogenic conditions or in the presence of low sulfate concentration (30 mg/l) than in the presence of higher sulfate concentrations (>400 mg/l). Therefore, different species of Dehalococcoides or other dechlorinating bacteria, which are not able to thrive in the presence of high sulfate concentrations (>400 mg/l), are possibly responsible for the higher dechlorination efficiency that was observed under methanogenic conditions.

This study evaluates the degree of pollution of marine sediments using two methods: standard (physico-chemical parameters) and instrumental techniques: thermogravimetric analysis (TG) and infrared spectroscopy (ATR-FTIR). ATR-FTIR proved to be a tool capable of identifying the organic and inorganic compounds in sediments such as organic carbon, clay, and carboxylate groups which can bind metal contaminants. TG results of 14 sediment samples were compared with organic matter (OM), organic carbon (OC), total nitrogen (TN), clay, and carbonate (CaCO₃) contents obtained by standard methods. The results showed that weight losses for a specific range of temperatures are closely correlated with the content of OM (R ² = 0.92), OC (R ² = 0.82), TN (R ² = 0.96), clay content (R ² = 0.87), and CaCO₃ (R ² = 0.9) for sediment samples. It is concluded that TG and ATR-FTIR allows a simultaneous, rapid, and reliable screening of sediment properties.

The nanoscale zero-valent iron supported on biochar (B-nZVI) was prepared by liquid-phase reduction method and used for the removal of acid orange 7 (AO₇). The structure of composited B-nZVI was characterized by transmission electron microscopy, scanning electron microscopy, X-ray diffraction analysis, X-ray photoelectron spectroscopy, and Brunauer-Emmett-Teller surface area analysis. nZVI was well dispersed on the surface of biochar with a specific surface area 52.21 m²/g, and no obvious aggregation was observed. Batch experiments demonstrated that the degradation of AO₇(20 mg/L) by B-nZVI (2 g/L) at initial pH 2 reached 98.3 % within 10 min. There was a good linearity (r² = 0.99) between kₒbₛand B-nZVI dosage. The reductive cleavage of the azo group in AO₇to amino group may be the dominant stage. This study demonstrated that B-nZVI has the potential to be a promising material for the removal of azo dyes.

Ametryne is an herbicide applied to sugar cane cultures to prevent the emergence of weeds. It is a persistent compound that percolates ground and surface water thus impacting aquatic communities. In this study, we evaluated microbial activity in soil with increased concentrations of ametryne solution and commercial Microgeo biofertilizer. The soil subject to analysis was obtained from a sugar cane cultivation area. The concentration used in the experiment was ametryne 12 μg/L and 1 % of biofertilizer. It was used with the Bartha and Pramer respirometric method to quantify CO₂production and determine microbial activity. Complimentary phytotoxicity tests with Lactuca sativa seeds after respirometry experiments were conducted in the soluble fraction of the soil. According to the results, the addition of biofertilizer promoted microbial activity in the presence of ametryne and reduced ametryne phytotoxicity for Lactuca sativa seeds. Thus, Microgeo biofertilizer can potentially improve biodegradation of ametryne through both bioaugmentation and bioestimulation.

A novel sorbent, chitosan-immobilized pumice, has been prepared for the sorption of As(V) from waters prior to its determination by hydride generation atomic absorption spectrometry. The success of the immobilization has been checked with such characterization techniques as scanning electron microscopy, thermal gravimetric analysis, and elemental analysis. Points of zero charge of the sorbents were determined with potentiometric mass titration. Batch-type equilibration studies have shown that the novel sorbent can be employed at a wide pH range resulting in quantitative sorption (>90 %) at pH 3.0–7.0 and greater than 70 % sorption at pH >8.0. These results demonstrate the advantage of immobilizing chitosan onto pumice, because, under the same conditions, pumice displays <20 % sorption toward As(V), whereas chitosan gives approximately 90 % sorption only at pH 3.0. The validity of the method was verified through the analysis of ultrapure, bottled drinking, and tap water samples spiked with arsenate; the respective sorption percentages of 93.2 (±0.7), 89.0 (±1.0), and 80.9 (±1.3) were obtained by batch-type equilibration. Arsenic sorption was also examined in the presence of common interfering ions resulting in competing effects of PO₄ ³⁻ and NO₃ ⁻ on As(V) adsorption.

Filtration can be a convenient technique for removing phosphorus (P) at on-site wastewater treatment facilities to recycle this non-renewable element. When testing potentially suitable materials for these filters, the properties of the influent and the method used to analyse measured effluent concentrations both affect the P binding capacity determined in filter tests and therewith filter longevity predictions. At present, there is a lack of robust methods for material investigation and filter test interpretation. This study was conducted to investigate the effect of inflow PO₄–P concentrations (concentration) and hydraulic surface load (load) on P binding capacity and to analyse possible interpretations of laboratory filter tests. A 2²factorial experiment with replicates was performed on the calcium-based filter material Filtra P. The investigated concentrations ranged from 12 to 50 mg L⁻¹and loads from 419 to 1,023 L m⁻² day⁻¹. P binding capacity (calculated by mass balance including data until PO₄–P breakthrough point) was negatively affected by concentration and positively affected by load, with the effect of concentration being slightly greater. Depending on the factors' settings and on the method of evaluation (i.e. analysing all pre-saturation data or considering only pre-breakthrough results), the total measured P binding capacity varied between 2.2 and 9.0 g kg⁻¹. The part of the breakthrough curve between the breakthrough point and saturation contributed significantly to the measured P binding capacity, and it took about three times longer for the filters to become saturated than to reach breakthrough. Furthermore, a considerable amount of P that had reacted with the filter material was washed out of the filters as particle-bound P. This indicates that it is important to determine both the PO₄–P and the particle-bound P phases in the filter effluent.

The dynamic behavior of water quality and quantity in the Egyptian drains is often viewed as a disruption to the normal operation and performance of the process of water reuse in irrigation. The control of such behavior has been challenging and often elusive in practice. Therefore, this paper presents a framework to advance the understanding and opportunities for improving the reuse process by developing a multivariate process control model. The model starts with preliminary analysis for water quality data that are collected at the reuse site on the examined drain. This phase comprises investigating data distribution and dependency. Then, univariate control charts are used to investigate the state of control for the independent and normally distributed variables. For dependent variables, principal components analysis is used as a method of synthesizing the variables information. In this case, principal component scores are displayed using multivariate control charts. If in-control case existed, process capability index is used to provide a numerical measure of whether or not the reuse process is capable of producing water that satisfies the irrigation quality standards. Since the model will only detect assignable causes if out-of-control or in-capable case existed, management, operational, and/or engineering action will usually be necessary to sustain the reuse process. In these cases, an action plan in response to the model signals will be vital. The main function of the proposed model is to safely manage the reuse practice using statistical quality control techniques. The model was demonstrated using water quality data collected during the period from January 2006 to July 2011 from Hanut (EH02) and El-Salam 3 (ESL03) pump stations along Hadus drain, Eastern Nile Delta-Egypt. The recommended model is automatic, algorithmic, self-tuning, and computerizable.

Water quality protection has become a key concern in water resources development and management. Uncontrolled nutrient input may challenge the quality of some water bodies. This study uses the relatively steep Kan watershed located in the north-west of Tehran (Iran) as an example case study, where an artificial lake is currently under construction for recreational purposes. Two approaches to predict the total annual phosphorous load were assessed: the soil and water assessment tool (SWAT) and the export coefficient approach. River discharge and sediment transport were simulated prior to modeling of the total phosphorous (TP) load in SWAT to make the model more accurate. In addition, an upstream to downstream calibration method was utilized. Findings reveal that the SWAT-simulated phosphorous load had sound Nash–Sutcliffe efficiency (ENS) values (ENSof 75 % for calibration and ENSof 52 % for validation). The relative error in estimating annual TP load was 7 %. The export coefficient approach assigning coefficients of export for each land use is known as an alternative method that can be used for estimating the TP load. Four sets of export coefficients were selected from the literature to examine their suitability in TP load prediction. The results showed significant errors in TP load prediction, which indicates that export coefficients are likely to be watershed-specific. Likewise, the export coefficients were found to vary through four wet months with errors ranging from 9 % to 33 %. This paper demonstrates that the export coefficient method may estimate the pollution load in the Kan watershed with less data than the advance SWAT model. However, it is associated with a higher level of error.

In this work, the sorption of pentachlorophenol (PCP) by non-viable biomass of Rhizopus oryzae ENHE was evaluated. The kinetics and isotherm studies were performed at pH 5.0, 6.0, and 8.0. The point of zero charge of the biomass was determined; this value allowed us to explain the changes of pH during sorption studies. The analyzed experimental kinetic data revealed that Ho’s model adjusted better to the experimental data than Lagergren’s model. PCP sorption was fast; an equilibrium sorption time was reached within 30 min, regardless of pH. PCP sorption at pH 5.0 and 6.0 was better described by the Freundlich isotherm than by the Langmuir isotherm. In contrast, at pH 8.0, the Langmuir isotherm describes better the PCP sorption. Sorption data showed that at pH 5.0 and 6.0, the sorption capacity of PCP was higher than at pH 8.0. Sorption of PCP by the fungal biomass occurred spontaneously; it was endothermic and due to physical sorption. Finally, FT-IR analysis of the dried biomass indicated that amino and hydroxyl groups were involved in the sorption of PCP. This work is one of the few reporting the effect of pH and temperature on the sorption of PCP by microbial biomass from a filamentous fungus belonging to the genus Rhizopus.