Heavy Metal Contaminated Food Crops Irrigated with Wastewater in Peri Urban Areas, Zambia

Studies on peri urban farming in Zambia have not adequately tackled the issues pertaining to heavy metal contaminated wastewater irrigation farming. The study investigated heavy metal contamination of water, soils and crops at two peri urban areas in Zambia. Two study sites were New Farm Extension in Mufulira Town in the Copperbelt Province and Chilumba Gardens in Kafue Town in Lusaka Province. The heavy metals investigated were lead, copper, cobalt, nickel and chromium. These heavy metals were found to be higher than acceptable limits in wastewater used to irrigate crops and there are potential human health risks associated with consumption of heavy metal contaminated food crops which have implications on the livelihoods of people. Samples of water, soil and crops were collected and analysed for lead (Pb), copper (Cu), chromium (Cr), cobalt (Co) and nickel (Ni) using the Atomic Absorption Spectrometer (AAS). The data on heavy metals was analysed using mean, standard error and T-test. The results indicated that the levels of heavy metals in wastewater, soil and food crops were above acceptable limits at two study sites. It can be concluded that there was heavy metal contamination of wastewater, soil and food crops at the two peri-urban areas in Zambia. The study highlighted the actual levels of heavy metal contaminant uptake in food crops consumed by the peri urban population. The information from this study can be used by the relevant authorities to develop appropriate measures for monitoring and control of heavy metal contamination in wastewater irrigation farming systems in peri urban areas inZambia.

Distribution and State of Ni Contaminants on Resid Fluid Catalytic Cracking Catalysts—Characterization by AEM, EPMA, UV-Vis and TPR

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Concept for Separation of Different Wastewater Streams in Order to Minimize Emerging Contaminants in Drinking Water

Abstract:In the recent past,trace levels of many contaminants were reported in drinking water.Substances that are resistant to bacterial degradation will flow along with treated effluent and will end up in inland surface waters from which raw water is extracted for public water supply systems.In certain extreme situations,presence of excessive concentrations of these contaminants can inhibit bacterial degradation of biological wastewater treatment processes.Therefore,there is a natural tendency for build-up of these contaminants in water sources.The emerging contaminants found in drinking water are heavy metals and hazardous substances that flow along with industrial effluent,hospital effluent and agricultural runoff.In order to remove these substances that are resistant to biological wastewater treatment,it is recommended to separate them in concentrated form by a separate collection system without allowing to mix with other wastewater streams.For wastewater other than domestic nature containing heavy metals,residual dies etc.and hazardous wastewater generated from hospitals such as radioactive iodine treatment for cancer patients,chemicals used for X-ray processing,amalgam used by dentists to fill up cavities,antibiotics,laboratory chemicals such as salicylic acid,benzoic acid,ethidium bromide(used for molecular biology research),xylene,formalin for preserving biological specimens,etc.,must be separated in concentrated form in a separate collection system without mixing with wastewater of domestic nature and disposed after treatment as hazardous wastewater.As per the“Policy on Siting of High Polluting Industries”,it is not possible to locate industries that are categorized as Type“A”high polluting industries upstream of intakes that extract raw water to produce potable water supply as it is very difficult to remove these substances by conventional water treatment techniques.

Characterization of Four University Hospitals Wastewater in Cotonou, Benin

Introduction: Because of the specificity of their care activities, hospital wastewater contains various contaminants such as germs, disinfectants, metals, pharmaceuticals and chemical reagents, potentially infectious or toxic, which can be harmful to living organisms, or create ecological damage. This study aimed to analyze the quality of wastewaters produced by university hospitals of Cotonou in Benin. Methods: We conduct an analytical cross-sectional study including 30 wastewater samples from selected hospitals. An analysis of variance was performed at the significance level of 0.05. Results: Microbiological analysis showed the presence of germs such as total coliform types, faecal coliforms, fecal streptococcus, staphylococcus, yeasts and Clostridium perfringens in hospital wastewater samples. There was a significant difference (p < 0.05) in the microbial loads of various germs, except staphylococcus, between hospitals. With regard to the physicochemical parameters, only the conductivity complied with the standards for the discharge of wastewater into the environment. A significant difference was noted between hospitals, for the electrical conductivity of wastewater (p < 0.05). The average levels of metals detected in the wastewaters were in line with Benin’s standards. There was no difference between the average concentrations of metals except for copper (p < 0.05). Conclusion: The wastewater produced by the university hospitals of Cotonou is of poor quality and therefore requires adequate prior treatment before discharge into the environment.

Chemically Induced Bioremediation of Heavy MetalContaminated Sewage-irrigated Soils in Tianjin Municipality

Festuca arundinacea L.was planted in sewage-irrigated soils from the sewage irrigation regions of Tianjin.Different concentrations of nitrilotriacetic acid（NTA）and sodium dodecylsulphate（SDS）were applied in bioremediation of Cd,Cu and Zn in sewage irrigation regions.According to the results,under the treatment of 15 mmol/kg NTA＋1 mmol/kg SDS,the concentrations of Cd and Zn reached the highest in shoots of F.arundinacea,which were 3.03 and 9.28 times over that in control,respectively;the concentrations of Cd and Zn in roots of F.arundinacea displayed the same trend as shoots.The combined addition of surfactant SDS and chelator NTA significantly increased Cd concentration in F.arundinacea,but the effect was not significant on Cu enrichment.Considering comprehensively the biomass,bioaccumulation effect and economic cost,it is economical and effective to remediate heavy metal-contaminated sewage-irrigated soils with 5mmol/kg NTA＋1 mmol/kg SDS or 10 mmol/kg NTA＋1 mmol/kg SDS.

Environmental Properties of Minerals and Contaminants Purified by the Mineralogical Method

The investigation of the environmental properties of minerals, i.e., environmental mineralogy, is a branch of science dealing with interactions between natural minerals and spheres of the Earth surface as well as a reflection of global change, prevention of ecological destruction, participation in biomineralogy, and remediation of environmental pollution. Pollutant treatment by natural minerals is based on the natural law and reflects natural self-purification functions in the inorganic world, similar to that of the organic world - a biological treatment. A series of case studies related to natural self-purification, which were mostly completed by our group, are discussed in this paper. In natural cryptomelane there is a larger pseudotetragonal tunnel than that formed by [MnO6] octahedral double chains, with an aperture of 0.462-0.466 nm2, filled with K cations. Cryptomelane might be a real naturally-occurring mineral of the active octahedral molecular sieve (OMS-2). CrⅥ-bearing wastewater can be treated by natural pyrrhotite, which is used as a reductant to reduce CrⅥ and as a precipitant to precipitate CrⅢ simultaneously. Batch experiments were conducted using the CTMAB-Montmorillonite as an adsorbent for aromatic contaminants (phenol, aniline, benzene, toluene and xylenes), which are detected frequently in the leaching water from municipal waste deposits around China. The CTMAB modification has proved very effective to enhance the adsorption capacity of the sorbent. Expansion of vermiculite develops loose interior structures, such as pores or cracks, inside briquettes, and thus brings enough oxygen for combustion and the sulfation reaction. Effective combustion of the original carbon reduces the amount of dust in the fly ash.

Geochronology, Geochemistry and Sr-Nd-Pb-Hf Isotopes of No. I Complex from the Shitoukengde Ni–Cu Sulfide Deposit in the Eastern Kunlun Orogen, Western China: Implications for the Magmatic Source, Geodynamic Setting and Genesis

The Shitoukengde Ni-Cu deposit, located in the Eastern Kunlun Orogen, comprises three mafic-ultramafic complexes, with the No. I complex hosting six Ni-Cu orebodies found recently. The deposit is hosted in the small ultramafic bodies intruding Proterozoic metamorphic rocks. Complexes at Shitoukengde contain all kinds of mafic-ultramafic rocks, and olivine websterite and pyroxene peridotite are the most important Ni-Cu-hosted rocks. Zircon U-Pb dating suggests that the Shitoukengde Ni-Cu deposit formed in late Silurian （426-422 Ma）, and their zircons have ~Hf（t） values of-9.4 to 5.9 with the older TDMm ages （0.80-1.42 Ga）. Mafic-ultramafic rocks from the No. I complex show the similar rare earth and trace element patterns, which are enriched in light rare earth elements and large ion iithophile elements （e.g., K, Rb, Th） and depleted in heavy rare earth elements and high field strength elements （e.g., Ta, Nb, Zr, Ti）. Sulfides from the deposit have the slightly higher ~34S values of 1.9-4.3%o than the mantle （0 ~ 2%o）. The major and trace element characteristics, and Sr-Nd-Pb and Hf, S isotopes indicate that their parental magmas originated from a metasomatised, asthenospheric mantle source which had previously been modified by subduction-related fluids, and experienced significant crustal contamination both in the magma chamber and during ascent triggering S oversaturation by addition of S and Si, that resulted in the deposition and enrichment of sulfides. Combined with the tectonic evolution, we suggest that the Shitoukengde Ni-Cu deposit formed in the post-collisional, extensional regime related to the subducted oceanic slab break-off after the Wanbaogou oceanic basalt plateau collaged northward to the Qaidam Block in late Silurian.

Electrochemical reduction characteristics and mechanism of nitrobenzene compounds in the catalyzed Fe-Cu process

The reduction of the nitrobenzene compounds （NBCs） by the catalyzed Fe-Cu process and the relationship between the electrochemical reduction characteristics of NBCs at copper electrode and reduction rate were studied in alkaline medium（pH=11）. The catalyzed Fe-Cu process was found more effective on degradation of NBCs compared to Master Builder＇s iron. The reduction rate by the catalyzed Fe-Cu process decreased in the following order： nitrobenzene 〉4-chloro-nitrobenzene ≥m-dinitrobenzene ：〉 4-nitrophenol ≥2,4-dinitrotoluene 〉2-nitrophenol. The reduction rate by Master Builder＇s iron decreased in the following order： m-dinitrobenzene ≥4-chloro-nitrobenzene 〉4-nitrophenol 〉2,4-dinitrotoluene ≈nitrobenzene 〉2-nitrophenol. NBCs were reduced directly on the surface of copper rather than by the hydrogen produced at cathode in the catalyzed Fe-Cu process. The reduction was realized by the hydrogen produced at cathode and Fe（OH）2 in Master Builder＇s iron, It is an essential difference in reaction mechanisms between these two technologies. For this reason, the reduction by the catalyzed Fe-Cu depended greatly on NBC＇s electron withdrawing ability.

Chemical and Organic Contamination of Phreatic Aquifer of Sidi Bouzid （Center West of Tunisia）

An understanding of the long-term changes in the nitrate and microbial contamination pattern of the groundwater of Sidi Bouzid （Centre West of Tunisia） is critical to conservation of drinking water in rural areas supporting mixed land-use activities such as cropping, livestock farming, and residence. The phreatic aquifer was revealed polluted by domestic disposals of the wastewaters in the urban zone. The average nitrate concentration in the groundwater of the east of the mioplioquaternary aquifer of Saddaguia （Sidi Bouzid） rose from 50 mg NO3- during 1996 to over 100 mg in 2003, which represents an increase of some 10 mg per year. Nitrate groundwater pollution during the period 1996-2003 was the result of the abusive use of fertilizers.In the cultivated zone, we must reduce the effects of the excessive use of the nitrogen fertilizers on the basis of monitoring soil once a year, managing water resources, rationalizing the use of the chemical substances. In urban zones, most of lost wells located in the perimeter reveal the gravity of the state of the aquifer. This last is organically polluted and requires an immediate action for the generalization of the purification network. We need to take into account the reality of under soil in all future planning＇s and arrangements. A scheme of sanitation seems necessary before all plans of arrangement. The extension of the sewer network must give the priority to the most vulnerable zones.

Influence of the Silicon- and Element-Organic Compounds on the Process of Biochemical Oxidation in the Organic Contaminations

One of the methods used in practice for the purification of wastewater from vegetable-processing enterprises is biological method of aerobic purification. With the aim to increase air-tank capacity used in traditional systems of biochemical purification of wastewater, different ways effecting to the process of vital activity of microorganisms of active sludge are applied. On the one hand, using the compositions of different salts and complex organic biogenous supplements prevents from the accumulation of some anions in the amounts exceeding the limited concentration, on the other hand- allows different groups of microorganisms to choose biogenous elements, which they assimilate easily and fully. It is known, that compounds of silicon and germanium can cause stimulating effects [1] to the organisms of active sludge. The goal of present studies is the intensification of biological processes of oxidation of organic contamination in wastewater by new bio-degradable chemical compounds or compositions on their basis, and by bio-sorbents.

Soil Explorations and Groundwater Monitoring to Evaluate Subsurface Contamination Due to Chromium in District Kasur, Pakistan

Due to improper tannery wastewater management in district Kasur Pakistan, groundwater has been reported to be highly contaminated. It was aimed to find out the extent up to which subsurface has contaminated due to chromium in areas adjacent to the tannery units. Eight （8） soil bores were conducted up to the depth of 30.5 meters and soil samples were tested for total and hexavalent chromium concentrations retained in soil by aqua regia digestion at the every depth of 1.5 meters. Afterwards monitoring wells were installed in these eight （8） bores so as to monitor chromium concentrations in the groundwater on monthly basis. The main source of contamination was considered to be the four （4） drains carrying tanneries effluent therefore samples were collected from these drains so as to observe seasonal variation in chromium concentration.

塔里木陆块周缘岩浆Cu-Ni-Co硫化物矿床形成的探讨

因新发现的夏日哈木超大型岩浆铜镍钴硫化物矿床成岩成矿研究存在争议,对岩浆铜镍钴硫化物矿床的成因机制又引发新一轮的关注。中国造山带中铜镍钴硫化物矿床具有鲜明的分布特点,20世纪80年代东天山黄山东等一批岩浆铜镍钴硫化物矿床的发现,曾经提出蛇绿岩形成铜镍钴硫化物矿床的观点,而后出现了洋壳削减闭合陆-陆碰撞后新生陆壳裂陷槽环境形成铜镍钴矿的主流认识;进入21世纪后,随着塔里木早二叠世大火成岩省的提出,开始将东天山和新疆北山的岩浆铜镍钴硫化物矿床与塔里木大火成岩省的形成关联起来,并认为是地幔柱作用的结果。但随着研究的深入,由于含铜镍钴镁铁-超镁铁岩地球化学具有典型的岛弧特征,又将东天山铜镍钴矿床的形成与俯冲削减的板片再次联系了起来,导致岩浆型铜镍钴硫化物矿床形成背景还存在较大争议。我们认为岩石微量元素显示岛弧信息,是俯冲交代及地壳混染引起的地球化学屏蔽效应;铬尖晶石成分及所反映的氧逸度环境指示为张性环境,而非岛弧。塔里木陆块周缘3期岩浆铜镍钴硫化物矿床成矿代表了中国最重要的3期成镍事件,实际反映了塔里木陆块在全球大陆聚散演化中与超大陆之间关键的聚散事件:(1)新元古代金川Cu-Ni-PGE矿成矿代表了由于地幔柱作用以塔里木、扬子和西澳大利亚陆块之间的裂解为起点的罗迪尼亚超大陆裂解事件,直至早古生代形成原特提斯洋-古亚洲洋;(2)早古生代末夏日哈木Ni-Co矿则是代表冈瓦纳大陆南部裂解从而形成古特提斯洋的标志性事件;(3)晚古生代早二叠世坡-Cu-Ni矿应是地幔柱作用潘吉亚超大陆生长大火成岩省的深成相组成。本文系统总结了3个矿床的成矿特征,并对比了3个矿床的区别。尽管坡-在3个矿床中有基性程度最高的母岩浆,但坡-相对于夏日哈木、金川显示出低的地壳混染程度,特别是地壳硫混染程度,这可能是坡-成矿相对差的主要原因。此外坡-不仅地壳混染程度低,且其混染了较多的钙质,抑制了硫化物饱和。

镇江城内运河水COD含量的分析

通过对镇江城内运河水定点、连续采样,用重铬酸钾法测定分析,发现水中COD含量在4 82～119mg/L之间,部分水域的水质已经污染,COD含量随水流方向逐渐升高,生活污水的排放是影响COD含量的最主要因素。

Wastewater degradation by iron/copper nanoparticles and the microorganism growth rate

Nowadays, trends in wastewater treatment by zero-valent iron（ZVI） were turned to use bimetallic NZVI particles by planting another metal onto the ZVI surface to increase its reactivity. Nano size zero-valent iron/copper（NZVI/Cu0） bimetallic particles were synthesized in order to examine its toxicity effects on the wastewater microbial life, kinetics of phosphorus, ammonia stripping and the reduction of chemical oxygen demand（COD）.Various concentrations of NZVI/Cu0 and operation conditions both aerobic and anaerobic were investigated and compared with pure NZVI experiment. The results showed that addition10 mg/L of NZVI/Cu0 significantly increased the numbers of bacteria colonies under anaerobic condition, conversely it inhibited bacteria activity with the presence of oxygen. Furthermore,the impact of nanoparticles on ammonia stripping and phosphorus removal was also linked to the emitted iron ions electrons. It was found that dosing high concentration of bimetallic NZVI/Cu0 has a negative effect on ammonia stripping regardless of the aeration condition. In comparison to control, dosing only 10 mg/L NZVI/Cu0, the phosphorus removal increased sharply both under aerobic and anaerobic conditions, these outcomes were obtained as a result of complete dissolution of bimetallic nanoparticles which formed copper-iron oxides components that are attributed to increasing the phosphorus adsorption rate.

Removal of Ni(Ⅱ) from strongly acidic wastewater by chelating precipitation and recovery of NiO from the precipitates

Strongly acidic wastewater produced in nonferrous metal smelting industries often contains high concentrations of Ni(Ⅱ), which is a valuable metal. In this study, the precipitation of Ni(Ⅱ) from strongly acidic wastewater using sodium dimethyldithiocarbamate(DDTC) as the precipitant was evaluated. The effects of various factors on precipitation were investigated, and the precipitation mechanism was also identified. Finally, the nickel in the precipitates was recovered following a pyrometallurgical method. The results show that, under optimised conditions(DDTC:Ni(Ⅱ) molar ratio = 4:1;temperature = 25 ℃), the Ni(Ⅱ) removal efficiency reached 99.3% after 10 min. In strongly acidic wastewater, the dithiocarbamate group of DDTC can react with Ni(Ⅱ) to form DDTC –Ni precipitates. Further recovery experiments revealed that high-purity Ni O can be obtained by the calcination of DDTC –Ni precipitates, with the nickel recovery efficiency reaching 98.2%. The gas released during the calcination process was composed of NO_(2), CS_(2), H_(2)O, CO_(2), and SO_(2). These results provide a basis for an effective Ni(Ⅱ) recovery method from strongly acidic wastewater.

Phenol contaminated municipal wastewater treatment using date palm frond biochar:Optimization using response surface methodology

Phenol is classified as an emerging contaminant which can be very toxic even at low concentrations and should be removed from wastewaters before reaching the environment.In this study date palm frond and leaf were pyrolyzed at different temperatures to identify the best adsorbent(feedstock)and pyrolysis temperature to remove phenol from aqueous solutions.Date palm frond pyrolyzed at 600℃,termed DPF600,achieved the highest phenol removal rates of 64%and adsorption capacity of 15.93 mg/g.Response surface methodology approach using Box-Behnken design was implemented to obtain the optimal pH(6),contact time(20 h)and dosage(0.1 g)for the maximum phenol adsorption.A predicted adsorption capacity was found as 16.62 mg/g which was in close agreement with the experimental adsorption capacity of 17.38 mg/g.Isotherm and kinetic models in both linear and non-linear forms indicated that Freundlich model(R^(2)=0.99,χ^(2)=0.02,RMSE=1.09)and pseudo-second order model(R^(2)=0.99,χ^(2)=0.85,RMSE=5.41)fit best the obtained experimental data.Thermodynamics calculations affirmed that the adsorption of phenol onto DPF600 biochar was endothermic and spontaneous.The point of zero charge was found to be at 6.5 for DPF600 biochar.Scanning electron microscopy coupled with energy dispersive X-ray,Fourier transform infrared spectroscopy and X-ray diffraction confirmed adsorption of phenol onto DPF600 biochar.Application of DPF600 biochar to remove phenol from synthetic primary and secondary treated wastewater samples achieved 60 and 85%removal rates and 241 mg/g and 22.28 mg/g adsorption capacities,respectively.Regeneration studies showed promising adsorption capacities indicating the efficacy of DPF600 for the removal of phenol from wastewater.

Contaminant Removal of Domestic Wastewater by Constructed Wetlands： Effects of Plant Species

A comparative study of the efficiency of contaminant removal between five emergent plant species and between vegetated and unvegetated wetlands was conducted in small-scale （2.0 m×1.0 m×0.7 m, lengthxwidthxdepth） constructed wetlands for domestic wastewater treatment in order to evaluate the decontaminated effects of different wetland plants. There was generally a significant difference in the removal of total nitrogen （TN） and total phosphorus （TP）, but no significant difference in the removal of organic matter between vegetated and unvegetated wetlands. Wetlands planted with Canna indica Linn., Pennisetum purpureum Schum., and Phragmites communis Trin. had generally higher removal rates for TN and TP than wetlands planted with other species. Plant growth and fine root （root diameter ≤ 3 mm） biomass were related to removal efficiency. Fine root biomass rather than the mass of the entire root system played an important role in wastewater treatment. Removal efficiency varied with season and plant growth. Wetlands vegetated by P. purpureum significantly outperformed wetlands with other plants in May and June, whereas wetlands vegetated by P. communis and C. indica demonstrated higher removal efficiency from August to December. These findings suggest that abundance of fine roots is an important factor to consider in selecting for highly effective wetland plants. It also suggested that a plant community consisting of multiple plant species with different seasonal growth patterns and root characteristics may be able to enhance wetland performance.

Fukushima wastewater release:unanswered questions and global concerns

The decision by Japan to begin discharging the Fukushima wastewater into the ocean on August 24,2023 was followed by protests from several countries,including China,Russia,Korea,Vietnam,and deep concerns from the international community.This decision is related to the aftermath of the Fukushima Daiichi nuclear disaster that occurred in 2011,which destroyed the cooling system of the nuclear power plant and caused the reactor cores to overheat.Much water was used to cool down the reactors fuel rods;about 1.3 million cubic meters contaminated water with highly radioactive material was generated,which can fill more than 500 Olympic swimming pools[1].In order to reduce the levels of radioactivity,an Advanced Liquid Processing System(ALPS)was used to remove most radioactive contaminants from water.ALPS works by circulating water through a system of tanks and filters,which removes specific contaminants such as cesium and strontium,using a multi-step process that includes coagulation,flocculation,ion exchange,and absorption[1].Japan's government and some scientists have argued that the ALPS-treated water is safe for release into the ocean.According to their claims,the discharged water poses minimal risk to human health and the environment.However,concerns about the long-term effects of this discharge remain in scientists′minds.

New concept of contaminant removal from swine wastewater by a biological treatment process

Pollution from concentrated animal feeding operations(CAFOs)are the most serious pollution source in China now,and swine wastewater contains high concentrations of nutrients such as chemical oxygen demand(COD),biochemical oxygen demand 5(BOD 5),ammonium,and emergent contaminants related to public health.Biological processes are the most popular treatment methods for COD and ammonium removal.Considering the low operation cost,easy maintenance and high removal rate of contaminants in recent years,nitrogen removal via nitrite and real-time control processes using oxidation-reduction potential(ORP)and/or pH as parameters to control the aerobic and anaerobic cycles of a system has received much attention for animal wastewater treatment.During the biological treatment process,the emergent contaminants such as estrogen,antibiotics,and disinfec-tion reagents have been the focus of research recently,and degradation bacteria and resistance bacteria have also been extracted from activated sludge.The microbial analysis technique is also advancement in the field of biodegrada-tion bacteria and resistance bacteria.All of these advance-ments in research serve to improve wastewater treatment and decrease environmental hazards,especially for using manure as a fertilizer source for crop production.

Biochar and zero-valent iron sand filtration simultaneously removes contaminants of emerging concern and Escherichia coli from wastewater effluent

Advanced treated municipal wastewater is an important alternative water source for agricultural irrigation.However,the possible persistence of chemical and microbiological contaminants in these waters raise potential safety concerns with regard to reusing treated wastewater for food crop irrigation.Two low-cost and environmentally-friendly filter media,biochar(BC)and zero-valent iron(ZVI),have attracted great interest in terms of treating reused water.Here,we evaluated the efficacy of BC-,nanosilver-amended biochar-(Ag-BC)and ZVI-sand filters,in reducing contaminants of emerging concern(CECs),Escherichia coli(E.coli)and total bacterial diversity from wastewater effluent.Six experiments were conducted with control quartz sand and sand columns containing BC,Ag-BC,ZVI,BC with ZVI,or Ag-BC with ZVI.After filtration,Ag-BC,ZVI,BC with ZVI and Ag-BC with ZVI demonstrated more than 90%(>1 log)removal of E.coli from wastewater samples,while BC,Ag-BC,BC with ZVI and Ag-BC with ZVI also demonstrated efficient removal of tested CECs.Lower bacterial diversity was also observed after filtration;however,differences were marginally significant.In addition,significantly(p<0.05)higher bacterial diversity was observed in wastewater samples collected during warmer versus colder months.Leaching of silver ions occurred from Ag-BC columns;however,this was prevented through the addition of ZVI.In conclusion,our data suggest that the BC with ZVI and Ag-BC with ZVI sand filters,which demonstrated more than 99%removal of both CECs and E.coli without silver ion release,may be effective,low-cost options for decentralized treatment of reused wastewater.