Dissolved organic matter (DOM) may alter the sorption of hydrophobic organic contaminants (HOC) to metal oxide nanoparticles (NPs), but the role of DOM and NP types is poorly understood. Here, phenanthrene sorption was quantified on four types of nano-TiO2 (three rutile, one anatase), and a bulk, raw TiO2 powder. Prior to the sorption experiments, these nanoparticles were coated using four different organic materials: Lignin (LIG), tannic acid (TAN), Congo red (CON), and capsorubin (CAP). Lignin, tannic acid, congo red and capsorubin coating substantially enhanced phenanthrene sorption to various TiO2 particles. After coating with a specific DOM, Kd values by the DOM-coated TiO2 particles on percent organic carbon content and surface area (SA) basis (Koc/SA) generally followed the order: TiO2 NPs with hydrophobic surfaces > bulk TiO2 particles > other TiO2 NPs. Different Koc/SA values of various DOM-TiO2 complexes resulted from distinct conformation of the coated DOM and aggregation.

Anthropogenic nitrogen (N) discharges has caused eutrophication in coastal zones. Ammonia-oxidizing bacteria (AOB) convert ammonia to nitrite and play important roles in N transformation. Here, we used pyrosequencing based on the amoA gene to investigate the response of the sediment AOB community to an N pollution gradient in the East China Sea. The results showed that AOB assemblages were primarily affiliated with Nitrosospira-like lineages, and only 0.4% of those belonged to Nitrosomonas-like lineage. The Nitrosospira-like lineage was separated into four clusters that were most similar to the sediment AOB communities detected in adjacent marine regions. Additionally, one clade was out grouped from the AOB lineages, which shared the high similarities with pmoA gene. The AOB community structures substantially changed along the pollution gradient, which were primarily shaped by NH4+–N, NO3−–N, SO42−–S, TP and Eh. These results demonstrated that coastal pollution could dramatically influence AOB communities, which, in turn, may change ecosystem function.

The simultaneous removal of phenol and ammonium using heterotrophic nitrifying-denitrifying bacterium Serratia sp. LJ-1 was investigated. The maximum removal rates of ammonium nitrogen and phenol were 1.08 ± 0.05 and 2.14 ± 0.08 mg L⁻¹ h⁻¹, respectively. The ammonium oxidation had much higher tolerance to phenol toxicity than that of the autotrophic nitrifying bacteria. The increase in phenol concentration led to an increase in ammonium oxidation rate under the phenol concentration of 600 mg L⁻¹. The increase in ammonium concentration caused an increase in phenol biodegradation rate under the ammonium nitrogen concentration of 150 mg L⁻¹. Maximum rates of phenol biodegradation and total nitrogen removal in the treatments with nitrification metabolite (nitrate or nitrite) as the sole nitrogen source were more than 30 % lower than those of the treatment with ammonium as the sole nitrogen source. Ammonium was removed through nitrification and subsequent aerobic denitrification while phenol was biodegraded through the ortho-cleavage pathway and subsequently mineralized. Since phenol often coexists with nitrogen pollutants, these findings have significant environmental implications in terms of the simultaneous removal of these contaminants.

The effect of anaerobic digestion (AD), coarse solids removal, and a manure additive More Than Manureᵀᴹ (MTMᵀᴹ) on ammonia (NH₃) emission from raw (Non AD) dairy manure and AD manure was studied during 110 days of storage. The study consisted of eight treatments in duplicate: AD manure and non AD manure, with and without coarse solids, and with and without MTMᵀᴹ additive. These studies were conducted in a naturally ventilated barn. The nitrogen content of manure, especially the ammoniacal nitrogen, played an important role in NH₃ emission. During the first 11 weeks of the storage, AD manure had significantly greater peak (33 to 38 ppm) concentrations of NH₃, and NH₃ fluxes (94 to 130 μg min⁻¹ m⁻²) compared to raw manure (14 to 25 ppm and 55 to 81 μg min⁻¹ m⁻², respectively). From the 11th week until the end of storage, there was no significant difference in NH₃ emissions across the manure treatments. The presence of course solids resulted in significanlty less peak NH₃ for non AD manure when data were evaluated for the whole storage period. The manure additive MTMᵀᴹ did not have a significant effect on NH₃ emissions during storage, however, temperature was positively related to NH₃ emissions. Total ammoniacal nitrogen and solids concentration in manure was the most important factors affecting NH₃ emissions during storage.

Many of municipal wastewater treatment plants (WWTPs) are operated by biological process with their excellent performances. However, the early warning system in the influent line is required to avoid the process malfunction because the biological wastewater treatment system has serious drawback to toxic chemicals in the influent. In order to develop a new type of biosensor using anaerobic granules in an online device for rapid detection of toxic inhibitory to the biological process, a porous pot reactor and an anaerobic granule biosensor (AGB) were demonstrated as an upset early warning device (UEWD) in this study. In the first group of toxic loading tests, the prepared cupric chloride solutions were separately injected into both the porous pot and AGB systems at six different concentrations, and phenol solutions were used at three different concentrations in the second group of tests. The results showed the chemical oxygen demand (COD) and ammonia nitrogen (ammonia-N) removal efficiency from porous pot reactor decreased dramatically in response to the addition of Cu²⁺and phenol with the variation of the oxidation-reduction potential (ORP) in AGB. The response of AGB system was 6 to 20 h in advance of porous pot reactor performance response, which suggests that the AGB could potentially be used as an online UEWD.

A study on the surface modification of uncontaminated sediment dredged for new port development with surfactant was performed, and the effectiveness of surface modified sediment for in-situ capping to control pollutant (N, P) release from the contaminated coastal sediments into seawater was also investigated. From this experiment, the adsorbed amount of surfactants on the surface of sediment particles was increased with the increase in the surfactant concentration. A more feasible method for the sediment modification with surfactants was mechanical shaking for 3 h, compared to sonication for 30 min or microwave radiation for 3 min. The adsorption capacities of the sediments modified with cationic surfactant (hexadecyltrimethylammonium bromide [HDTMA]) were 40 mg g⁻¹ for ammonia-nitrogen, 16 mg g⁻¹ for nitrate-nitrogen, 31 mg g⁻¹ for phosphorus, which are higher those of the sediment modified with anionic (SDS) and nonionic surfactants (TX-100). The capping layer with the sediment modified with HDTMA in column experiment was effective for inhibiting the release of nitrogen and phosphorus from the contaminated sediment into overlying seawater, indicating that the cationic surfactant modified sediment is reusable as a good in-situ capping material for contaminated coastal sediment.

Water quality degradation is often a severe consequence of rapid economic expansion in developing countries. Methods to assess spatial-temporal patterns and trends in water quality are essential for guiding adaptive management efforts aimed at water quality remediation. Temporal and spatial patterns of surface water quality were investigated for 54 monitoring sites in the Wen-Rui Tang River watershed of eastern China to identify such patterns in water quality occurring across a rural-suburban-urban interface. Twenty physical and chemical water quality parameters were analyzed in surface waters collected once every 4–8 weeks from 2000 to 2010. Temporal and spatial variations among water quality parameters were assessed between seasons (wet/dry) and among major land use zones (urban/suburban/rural). Factor analysis was used to identify parameters that were important in assessing seasonal and spatial variations in water quality. Results revealed that parameters related to organic pollutants (dissolved oxygen (DO), chemical oxygen demand (manganese) (CODMₙ), and 5-day biochemical oxygen demand (BOD₅)), nutrients (ammonia nitrogen (NH₄⁺-N), total nitrogen (TN), total phosphorus (TP)), and salt concentration (electrical conductivity (EC)) were the most important parameters contributing to water quality variation. Collectively, they explained 70.9 % of the total variance. A trend study using the seasonal Kendall test revealed reductions in CODMₙ, BOD₅, NH₄⁺-N, petrol, V-phen, and EC concentrations over the 11-year study period. Cluster analysis was employed to evaluate variation among 14 sampling sites representative of dominant land use categories and indicated three, three, and four clusters based on organic, nutrient, and salt water quality characteristics, respectively. Factors that are typically responsible for water quality degradation (including population, topography, and land use) showed no strong correlation with water quality trends implying considerable point source inputs in the watershed. The results of this study help inform ongoing water quality remediation efforts by documenting trends in water quality across various land use zones.

Currently, the poor water quality in Taihu Lake is a major problem in China, so pollution control in the upstream areas has become a government priority. In Jiangsu Province, pollution emissions around the western areas of Taihu Lake, including Changzhou Municipality and Yixing City, need to be highly restricted, and calculating the water environmental capacity is important if pollution is to be reduced. In this study, 19 control units in these areas were established, and a 0-D mathematical model was used to calculate the water environmental capacity. For three important control units with important cross sections, a 1-D model was established to redress the results. Finally, the total maximum monthly loads of each control unit were obtained using temporal allocation principles. The results suggested that (1) the total pollution control of chemical oxygen demand was 58,894.2 tonnes per annum (t a⁻¹), with ammonia nitrogen, total nitrogen, and total phosphorus amounting to 3,808, 6,054.6, and 386.6 t a⁻¹, respectively; (2) water environmental capacity per unit water area in the ambient control units was smaller than that in the middle control units; and (3) the largest water environmental capacity was in June, and the smallest capacity was in December. The study provides important information for local governments, which will enable them to implement pollution control strategies that will improve the water quality in Taihu Lake.

Struvite precipitate obtained from yeast industry anaerobic effluent with high ammonium nitrogen (NH₄–N) was investigated for fertilizer effect on plant growth and nutrition according to applications of N, nitrogen/phosphorus/potassium (NPK), and control. Optimum struvite formation conditions were determined via Box–Behnken design. Optimum condition was obtained at pH 9.0 and Mg/N/P molar ratio of 1.5:1:1. Under these conditions, heavy metal concentrations in the obtained struvite precipitate (except Cu) were below the detection limits. In addition to high N, P, and Mg content, energy-dispersive X-ray (EDX) analysis showed that the struvite also included the nutritional elements Ca, K, Na, and Fe. X-ray diffraction (XRD) analysis revealed the complex structures of NaAl(SO₄)₂(H₂O)₁₂, NaMn²⁺Fe₂(PO₄)₃, and (Na₂,Ca)O₂(Fe,Mn)O.P₂O₅in the precipitate. High Na⁺and Ca²⁺concentrations in the anaerobic effluent reacted with phosphate during struvite precipitation. Different applications and struvite dosages significantly affected fresh and dry weights and nutrient element uptakes by plants (P < 0.05). N, P, and Mg uptakes of plants were significantly higher at struvite ×2, ×3, and ×4 dosages compared with NPK application. For adequate nutrition and supply of optimum dry weight, struvite ×2 dosage (5.71 g struvite/kg soil) was found appropriate for both maize and tomato plants.

The coking wastewater generally comprises highly concentrated, recalcitrant, and toxic organic pollutants, so its treatment has been of great importance to prevent living beings and their environment from these hazardous contaminations. The treatment of pretreated coking wastewater by flocculation-coagulation, alkali out, air stripping, and three-dimensional (3-D) electrocatalytic oxidation was performed (gap between the used β-PbO₂/Ti anode and titanium cathode, 12 mm; mass ratio of Cu-Mn/granular activated carbon (GAC) to effluent, 1:4; cell voltage, 7 V). The results showed that the pH adjusting from 3.7 to 6.1 was necessary for coagulants; alkali out played an important role because it brought up precipitation containing higher fatty acids as well as other contaminants to decrease the chemical oxygen demand (COD) in the effluent, and it had also forced the reduction of ammonia nitrogen (NH₃-N) by incorporating with air stripping; for 3-D electrocatalytic oxidation with a bleaching liquid assisting, the initial pH 8.5 of effluent was suitable for Cu-Mn/GAC; moreover, it was considered that its Cu component was dedicated to the decrease of COD and NH₃-N, while the Mn component specialized in the decay of NH₃-N. The residual COD and NH₃-N values in the final effluent with pH 6.5 were 95.8 and 8.8 mg/L, respectively, demonstrating that the whole processes applied were feasible and low in cost.