Advanced Oxidation with Nanofilm Photacatalyst’S on Stainless Steel Wire as Secondary Treatment of Wastewater

In this paper,authors reported the results of wastewater treatment of discharges from sanitary facilities and laboratories from de Metropolitan Autonomous University Azcapotzalco campus in Mexico city in a pilot plant integrated with a unit of coagulation-flocculation and sedimentation of suspended particulate and multilayer filtration with sand,zeolite and anthracite that filtered particulate higher than 5 nanometer of diameter as primary treatment and advanced oxidation based in the use of hydroxyl radical through ozonation and UV Photocatalysis with zinc oxide,zinc oxide doped with silver and zinc oxide doped with zirconia as fine films photocatalysts on a US 100 stainless steel wire as secondary treatment,and finally with activated carbon adsorption as final polish.COD and ORP were evaluated after each step as representative of BOD stablished as MAC’s in Mexican regulation on wastewater effluents,obtaining values that comply with the regulation.

Performance of a Demonstrative (Scale-Pilot) Double Advanced Oxidation Wastewater Treatment Plant to Treat Discharges from a Small Community in Morelia, Michoacán, México

This paper,reports the performance of a wastewater treatment scale-pilot plant to treat 2 GPM(Gallons per Minute)discharges with 5,205 mg/L of pollutants expressed in COD(Chemical Oxygen Demand),from“Lomas de la Maestransa”a small community in Morelia City,Michoacan,Mexico.The scale-pilot plant is a train with(1)pretreatment with a triturated pump for floating solid,(2)primary treatment with“in line”coagulation,and rapid filtration to retain suspended colloids and dissolved solids higher of 5μm diameter,(3)double advanced oxidation as secondary treatment with ozone and heterogeneous photo catalysis to oxidize volatile solids,and(4)tertiary treatment with activated carbon to retain refractory compounds.Plant performance was analyzed by a certified laboratory that belongs to Potable Water,Sewage and Sanitation Department from Morelia City Government.Results show that treated water effluent complied with the Mexican Official Standard NOM-001-SEMARNAT-1996 for discharges into national waters,with exception of fecal coliforms,since the raw water contains an average of 64,228,351 MNP/100 mL of fecal coliforms,and in spite that we obtained a 99.998%efficiency,the maximum level allowable 2,000 MPN/100 mL standard,was exceeded by 400 MPN/100 mL.After this experience,the wastewater treatment plant is equipped with a residual chlorine tank to keep a 1.5 ppm chlorine residual concentration to keep the treated water clean.This project was possible because we had the support of the Morelia Sanitation Department.

Improving Compost Process Efficiency by Leachates Inoculation and Shredding of the Organic Fraction of Municipal Solid Waste at Bordo Poniente Composting Plant,Mexico City

Management of MSW(Municipal Solid Waste)is a major downside in most of the biggest cities.The composting of the organic fraction of MSW is one of the oldest and simplest ways of organic waste stabilization.It is a self-heating biological conversion that generates appropriate finished merchandise such as soil conditioner or fertilizers.Mexico City generates about 12,500 ton/day of MSW,44%of it is food scraps and yard trimmings which are the OFMSW(Organic Fraction of Municipal Solid Waste),2,500 ton/day of it is composted at the BPCP(Bordo Poniente Composting Plant)yielding 500 ton/day of compost.The purpose of this study was to evaluate three treatments to accelerate the composting process,so eventually the city could increase the amount of the OFMSW at BPCP.We compared three different treatments;one of them showed a significant reduction in time of the composting process(p≤0.05)i.e.,it took less time to reach the thermophilic stage,maturity and stabilization phases.Maturity was achieved at 35 days and 60 days to stabilize.We conclude that shredding the feedstock plus leachate inoculum addition at the beginning of the process,reduces the composting time in about 61%with respect to the time it takes at the BPCP,where lasted 90 days.

Comparison between Two Urban Wastewater Primary Treatment Trains

This paper evaluated two different wastewater primary treatments of wastewater from the“Universidad Autonoma Metropolitana,Azcapotzalco Campus”,a conventional one integrated for coagulation,flocculation,sedimentation and filtration versus one alternative integrated for in-line coagulation to precondition to rapid filtration.The wastewater was from the Azcapotzalco Campus in Mexico City,and in both cases,we characterized the wastewater,measured:pH,conductivity,temperature,total dissolved solids,dissolved oxygen,ORP(Oxide Reduction Potential),turbidity,and COD(Chemical Oxygen Demand).Conventional treatment was slightly better treatment,but the alternative treatment represents saving in equipment,reactive,energy and time,so it was considered a viable technical and economic wastewater primary treatment.