WASTEWATER

Wastewater -used water (from human activity) -contains pollutants

Pollutant -In the recipient the creature’s life circumstances ( significant changes in the existing biological, biochemical processes) and the further use of water for humans will be limited or impossible

Other problems -aesthetic problems -odour problems -infection problems CLOSED sewerage system from the source to the recipient

History In the antique Rome was sewerage system also, and it caused no problem. Why is it a problem nowdays? What happend with the wastewater in the past years?

Organic substances -micro-organisms eat the most of it 2 CH O 2 → 2 CO H 2 O +energy + cell material LARGE OXYGEN-DEMAND!

Organic substances -higher lifeforms cannot get enough oxygen -photosynthesis is not enough -that much oxigen cannot dissolve from the air

Solution We have to reduce the amunt of organic materials getting into the recipient ↓ in order to keep the DO value above the critical level (DO = Dissolved Oxygen)

Dangerous wastewater ALWAYS: -infection danger PAST YEARS: -increasing population -urbanization -developing industry (chemicals) -concentration

Wastewater types Domestic wastewater: - human waste and washwater from houses (homes) Institutional wastewater: - human waste and washwater from public buildings and commercial establishments

Wastewater types -Industrial wastewater: used water from manufacturing processes - contains different chemical compounds -Municipal wastewater: mixture of domestic and industrial wastewater

Wastewater types Agricultural wastewater: dung from keeping animals Stormwater: surface runoff caused by rainfall - carries organics, suspended and dissolved solids, etc.

Amounts Domestic wastewater: Developing countries: less than 100 L/pe/day Middle-Europe:~100 L/pe/day Western countries: ~160 L/pe/day Hungary: (BP:180) L/pe/day

Amounts Industrial wastewater: - what kind of industry - number of working factories and units - type and level of the used technology

Industry -cooling water -producing chemicals -producing food -electronic industry -textile industry

Amounts Agricultural wastewater: - what kind of animals - number of the animals - level of the used technology

Characterization Chemical characterization Individual components: Sewage – impossible Industrial wastewaters – sometimes there is a possibility Municipal wastewater - impossible

Characterization Group characterization: Carbon Chemical Oxygen Demand (COD Cr = mg/l) Biochemical Oxygen Demand (BOD 5 = mg/l, BOD 7, BOD 20 ) Total Organic Carbon (TOC) Dissolved Organic Carbon (DOC) Volatile Organic Carbon (VOC)

WATER POLLUTION: Oxygen deficiency

EFFECT OF RAW WASTEWATER - BOD 5 emission increases, BOD 5 concentration increases, dissolved O 2 concentration decreases - O 2 is an important water quality indicator

WATER QUAILTY (O 2 ) - raw wastewater: 0 mg/l - saturation concentration (Henry’s law): ~ 10 mg/l (20 °C ) - fish reproduction:  6 mg/l (different sensitivity: age, specie (eg. trout 6-7 mg/l, carp 4 mg/l) - further water uses

Balance ORGANIC MATERIAL (C, N) SEDIMENT RESPIRATION DIFFUSION FROM AIR PHOTOSYNTHESIS TRIBUTARIES IN – OUT + O 2 diff – C decomposition – nitrification – sediment + photosynthesis – respiration +- tributaries

BOI O2O2 DISCHARGEO 2 INPUT SEDIMENTATION Streeter & Phelps (1925, River Ohio)

Characterization Group characterization: –Nitrogen –Phosphorus –Suspended solids –Other chemical, physical and biological parameters

NITROGEN ORGANICALLY BOUND INORGANIC AMMONIUM (NH 4 -N) NITRATE (NO 3 -N) NITRITE (NO 2 -N) 30 mg/l 50 mg/l 0.1 mg/l 0.5 mg/l No exact values!!!

PHOSPHORUS MAIN SOURCE DETERGENTS (50%) HUMAN EXCRETA (50%) ORGANICALLY BOUND SOLID INORGANIC POLYPHOSPHATES ORTHOPHOSPHATES (PO 4 3- ) DISSOLVED TP

PHOSPHORUS MAIN SOURCE DETERGENTS (50%) HUMAN EXCRETA (50%) ORGANICALLY BOUND SOLID INORGANIC POLYPHOSPHATES ORTHOPHOSPHATES (PO 4 3- ) DISSOLVED TP

PHOSPHORUS ORGANICALLY BOUND mg/L POLYPHOSPHATES mg/L ORTHOPHOSPHATES (PO 4 3- ) mg/L TOTAL PHOSPHORUS mg/L

ESTIMATING POLLUTANT LOAD AND CONCENTRATION BOD 5 : 60 g/d/person COD: 120 g/d/person TSS: 70 g/d/person TN: 11 g/d/person TP: 2.5 g/d/person drinking water consumption: q d = l/d/person

ESTIMATING POLLUTANT CONCENTRATION BOD 5 : 60 g/d/person TN: 11 g/d/person TP: 2.5 g/d/person calculating with 200 l/d/person: BOD 5 concentration: 60/200 = 0.03 g/l = 300 mg/l TN concentration: 11/200 = g/l = 55 mg/l TP concentration: 2.5/200 = g/l = 12.5 mg/l

Other parameters -pH -temperature -salt concentration ( ~ ability of leading electricity)

Europian Union -All member state should follow some rules -Derogation can be asked for (Hungary: 2015)

Europian Union - Difference between drinking water and the sewerage system supply - Difference between sewerage system supply and treating the collected wastewater

Europian Union Sensitive or non-sensitive area More or less, than 2000 person’s emission